Next Article in Journal
Interfacial Mechanism of Biological Property Enhancement in Irradiated MAO Coatings by HIPIB
Previous Article in Journal
Surface Modification of Screen-Printed Carbon Electrodes
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Coatings
Volume 15
Issue 10
10.3390/coatings15101183
coatings-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

The Application of Carbon-Based Materials in Cathodes for High-Performance K-Se Batteries: A Review

by
Jingyang Wang
1,*,†,
Yanfang Liang
1,†,
Dongqi Gu
1,
Can Li
2,
Zening Sui
1,
Xibo Tang
1,
Xiaobin Sun
3,* and
Yong Liu
1,*
1
Henan Key Laboratory of Non-Ferrous Materials Science & Processing Technology, School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China
2
Modo Institute of Technology, Henan University of Science and Technology, Luoyang 471023, China
3
China Lithium Battery Technology (Luoyang) Co., Ltd., Luoyang 471032, China
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Coatings 2025, 15(10), 1183; https://doi.org/10.3390/coatings15101183
Submission received: 29 July 2025 / Revised: 27 August 2025 / Accepted: 9 September 2025 / Published: 9 October 2025
Browse Figures
Versions Notes

Abstract

Potassium–selenium (K-Se) batteries have emerged as a promising energy storage system in view of their high theoretical energy density and low cost. However, their practical application is restricted due to challenges such as polyselenide shuttling, low redox activity, and significant cathode volume expansion during cycling, leading to inferior Coulombic efficiency and a short cycling lifespan. Carbon-based materials, with their superior electronic conductivity, adjustable pore structures, and robust chemical stability, have been extensively studied and employed as cathode materials in K-Se batteries, demonstrating remarkable potential in addressing the above-mentioned issues. Considering the rapidly growing research interest in this topic in recent years, herein, we comprehensively summarize recent advances in the application of carbon-based materials as cathodes in K-Se batteries. First, we introduce the properties, key challenges, and optimization strategies of K-Se batteries, including encapsulating Se within carbon materials, engineering chemisorptive hosts, and electrocatalyzing redox reactions. Furthermore, we discuss the relationship between fabrication strategies, micro/nanostructures, and electrochemical performances. Finally, we propose future prospects for the rational design and application of carbon-based cathodes in K-Se batteries and other alkaline metal–chalcogen batteries.

1. Introduction

Currently, lithium-ion batteries (LIBs) are widely used in the fields of portable electronics, smart grids, and electric vehicles due to their extended lifespan and minimal self-discharge [1,2]. However, the scarcity of lithium resources (crustal reserves are only 0.0017 wt%), along with their uneven spatial distribution and high cost, severely limits the further development of LIBs [3,4,5,6]. In this context, potassium-ion batteries (PIBs) have become a potential candidate due to their similar working principle to LIBs, abundant K resources (crustal reserves are ~2.1–2.6 wt%), and low cost [7,8]. Nevertheless, the large ionic radius of K+ can cause electrode volume expansion and kinetic retardation, driving researchers to explore high-performance K-based systems [9,10]. The electrochemical performance of PIBs is highly dependent on the cathode materials, particularly their capacity and redox potential [11]. The development of cathode materials with high capacity and high operating voltage is crucial yet remains challenging for constructing high-performance PIBs. Selenium-based cathodes have become a promising cathode system due to their high theoretical volume capacity (3253 mAh g−1) and high conductivity (1 × 10−3 S m−1) [12]. Compared with lithium–selenium (Li-Se) and sodium–selenium (Na-Se) batteries, which suffer from severe polyselenide dissolution and sluggish reaction kinetics, potassium–selenium (K-Se) batteries exhibit significantly reduced solubility of potassium polyselenide, thereby fundamentally suppressing the shuttle effect [13,14]. This advantage endows K-Se batteries with the potential for higher Coulombic efficiency and longer cycle life, making them a competitive candidate for next-generation energy storage systems [7,15].
A K-Se battery functions through the reversible conversion reaction between Se and K [16]. However, its practical application is mainly limited by challenges associated with the Se cathode, including the shuttle effect of polyselenide, low conductivity, low redox activity, and significant volume expansion during cycling [7,17,18]. In order to address these challenges, researchers have developed strategies including Se/C composites and Se/S molecular hybrids [19]. Among them, carbon-based materials have demonstrated remarkable potential for Se cathodes in K-Se batteries owing to their adjustable pore structures and high electrical conductivity, which enable both physical confinement of Se and chemical anchoring of polyselenide [20,21,22]. To date, most studies have focused on the application of carbon-based materials for cathodes in K-Se batteries. For example, Yao et al. developed a Se@NOPC-CNT composite cathode for a K-Se battery that maintained a capacity of 335 mAh g−1 after 700 cycles at 0.8 A g−1; the excellent electrochemical performance can be ascribed to the synergistic effects of N, O heteroatom co-doping, three-dimensionally interconnected carbon frameworks for efficient electron/ion transport, and nanopores for effective polyselenide confinement [23]. Furthermore, Lim et al. fabricated a Se@h-NMCNF composite cathode that exhibited enhanced rate and cycling performance due to its hierarchical porous carbon nanofiber structure that significantly improved Se utilization [24]. Some reviews have provided an overview of the development of carbon-based materials for K-Se batteries. For instance, Huang et al. comprehensively summarized recent advances in potassium–chalcogen (S, Se, and Te) batteries, including cathode materials [7]. Additionally, Du et al. systematically reviewed the applications of biomass-derived carbon in alkali-metal (Li, Na, K)–Se battery systems [25]. Although some reviews have summarized progress in K-Se batteries, to our knowledge, few comprehensive and timely reviews have systematically focused on carbon-based materials for cathodes in K-Se batteries, particularly regarding their structure and properties, applications, and future prospects.
Here, we summarize the recent developments in carbon-based materials for cathodes in high-performance K-Se batteries, including strategies such as encapsulating Se within carbon materials, engineering chemisorptive hosts, and electrocatalyzing redox reactions, as shown in Scheme 1. Moreover, the mechanism, main challenges, and optimization strategies for K-Se batteries are systematically discussed, while the current lack of a comprehensive understanding of their reaction mechanisms (particularly in small-molecule selenium systems) is also highlighted. In addition, some rational suggestions and future prospects for the application of carbon-based materials in cathodes for K-Se batteries are presented. Hopefully, this review will draw greater attention to the application of carbon-based materials in cathodes for K-Se batteries and accelerate their practical applications.

2. Mechanism, Challenges, and Optimization Strategies of Potassium–Selenium Batteries

Given the numerous advantages of selenium-based cathodes, selenium-based batteries have been extensively studied. In selenium-based batteries, both Li-Se and Na-Se systems are generally plagued by severe polyselenide dissolution/shuttling and sluggish reaction kinetics, leading to poor cycling stability [13]. In contrast, K-Se batteries exhibit significantly reduced solubility of selenium and polyselenide in carbonate-based electrolytes, which fundamentally suppresses the shuttle effect and contributes to improved energy density, Coulombic efficiency, and cycling stability [14]. Therefore, rechargeable potassium–selenium batteries have garnered considerable attention as an emerging energy storage technology. This section reviews the properties, challenges, and potential optimization strategies of K-Se batteries.

2.1. The Mechanism and Challenges of Potassium–Selenium Batteries

Rechargeable potassium–selenium batteries include a selenium cathode, a separator, an electrolyte, and a potassium anode [19]. Their electrochemical mechanism depends on the oxidation reaction of potassium and reduction reaction of selenium, with the reaction pathway determined by Se molecular configurations: the ring-like Se8 undergoes a two-step conversion to K2Se via polyselenide intermediates, while the polymeric Sen transforms either directly into K2Se or through polyselenide transition states; small-molecular Se species follow a solid-phase transformation pathway to form K2Se, which can effectively mitigate the shuttle effect [7,19]. Some progress in identifying the electrochemical mechanisms of K-Se batteries has been realized; however, a complete understanding of their electrochemistry remains elusive, especially mechanistic understanding in small-molecule Se systems. Although the understanding of its electrochemical behavior remains incomplete, selenium offers exceptional advantages for K-Se batteries, including excellent electronic conductivity (1 × 10−3 S m−1), high theoretical specific capacity (675 mAh g−1), and remarkable volumetric capacity (3253 mAh cm−3) [26]. Critically, studies confirm the unique stability of Se-based cathodes in carbonate electrolytes. Their one-step conversion mechanism avoids polyselenide formation, mitigating side reactions and enhancing electrode/electrolyte compatibility [18,27].
However, K-Se batteries still face many critical challenges: (1) Serious polyselenide shuttling. The reaction between the Se cathode and the K anode generates soluble polyselenide, whose shuttling causes active material loss and rapid capacity decay [16]. (2) Large volume expansion of Se cathode during cycling. K+ insertion during discharge triggers a 400% volume change in the cathode due to the different mass densities between Se and K2Sex, severely damaging electrode structural integrity [16,19]. (3) Low redox activity. The large atomic size of selenium restricts reaction kinetics, resulting in inferior Coulombic efficiency and cyclic stability [14,18].

2.2. The Optimization Strategies of Potassium–Selenium Batteries

Considering the challenges mentioned above, some optimization strategies have been proposed and applied to optimize the cathode of K-Se batteries, including encapsulating Se within carbon materials, engineering chemisorptive hosts, and electrocatalyzing redox reactions (Figure 1).
The optimization methods of K-Se batteries primarily focus on effectively inhibiting polyselenide shuttling, enhancing reaction kinetics, and improving electrode stability. Current studies mainly concentrate on the design of cathode materials, among which encapsulating Se within carbon materials has become the research focus due to their unique structural advantages [20,21]. The porous carbon materials effectively relieve the volume change in Se and facilitate ion transport through the hierarchical pore structure [26], while the closed space of hollow carbon structures inhibits the dissolution of polyselenide [28]. Heteroatom doping can enhance the chemical adsorption of polyselenide, improving the conductivity of materials and catalyzing the redox reaction [23]. Biomass-derived carbon materials maintain excellent electrochemical performance and reduced costs due to their natural porous structure and intrinsic heteroatom doping [29]. Notably, limiting Se to small molecules (Se2-4) can significantly reduce the phase transition stress and accelerate the reaction kinetics, offering a new approach to address the slow conversion of traditional ring-like Se8 [19,30]. Moreover, in terms of chemical adsorption, the introduction of polar materials or single-atom catalysts can achieve strong anchoring and efficient conversion of polyselenide [31]. In addition to the strategies mentioned above, the electrocatalytic strategy can lower the barrier for the Se conversion reaction and simultaneously accelerate the redox reaction kinetics [32].
Coatings 15 01183 g001
Figure 1. Schematic diagram of the challenges in K-Se batteries and the corresponding strategies in cathodes for K-Se batteries. Adapted with permission [25]. Copyright 2022, MDPI. Adapted with permission [26]. Copyright 2021, Elsevier B.V. Adapted with permission [32]. Copyright 2025, Elsevier B.V. Adapted with permission [31]. Copyright 2022, Elsevier Ltd.
Figure 1. Schematic diagram of the challenges in K-Se batteries and the corresponding strategies in cathodes for K-Se batteries. Adapted with permission [25]. Copyright 2022, MDPI. Adapted with permission [26]. Copyright 2021, Elsevier B.V. Adapted with permission [32]. Copyright 2025, Elsevier B.V. Adapted with permission [31]. Copyright 2022, Elsevier Ltd.
Coatings 15 01183 g001

3. Application of Carbon-Based Materials in Cathodes for Potassium–Selenium Batteries

The cathode represents a critical challenge for K-Se batteries; hence, stabilizing selenium-based cathodes plays an important role in improving the electrochemical performances of potassium–selenium batteries. Even though selenium has higher electronic conductivity than insulating sulfur, pure Se cannot be used directly as a cathode and requires conductive matrices to facilitate electron transfer [33]. The reversible conversion of Se in the cathode generates soluble potassium polyselenide that dissolves into the electrolyte, resulting in severe capacity degradation and eventual battery failure [7]. This critical challenge necessitates the development of spatially confined host materials to effectively inhibit the polyselenide shuttle effect, requiring cathode designs that simultaneously meet two essential parameters: high electronic conductivity for efficient charge transfer and robust immobilization of active Se species. Carbon-based materials have demonstrated significant potential in K-Se batteries owing to their unique combination of high electrical conductivity, adjustable pore structures, large specific surface area, and superior chemical stability. The inherent physicochemical characteristics make carbon-based materials a promising candidate to address the aforementioned challenges through innovative solutions. This section focuses on rational design strategies for carbon-based cathodes in K-Se battery cathodes, encompassing three key aspects: encapsulating Se within carbon materials, engineering chemisorptive hosts, and electrocatalyzing redox reactions. More details about the K-Se batteries’ performance employing different carbon-based cathode materials can be found in Table 1.

3.1. Encapsulating Se Within Carbon Materials

Encapsulating Se within carbon materials effectively addresses the inherent limitations of Se by utilizing the superior electrical conductivity of carbon to facilitate electron transport and enhance reaction kinetics. The substantial porous structure enables high Se loading capacity and promotes electrolyte penetration, while the high specific surface area offers abundant reaction sites for electrochemical reactions. Furthermore, the carbon materials could inhibit polyselenide dissolution/shuttling and accommodate the substantial volume variations in Se during cycling, thereby ensuring excellent electrode structural stability. Currently, the carbon-based materials employed in selenium-based cathodes include porous carbon [34,37], hollow carbon [42], doped carbon [44], and biomass-derived carbon [19].

3.1.1. Se/Porous Carbon Composites

Se/porous carbon composites have emerged as one of the most prevalent strategies for enhancing Se-based cathodes in recent years. According to their sizes, the pores are divided into three types: micropores, mesopores, and macropores. Microporous carbon may promote penetration of the liquid electrolyte, but its highly restricted pore volume does not provide sufficient storage space for Se. Mesoporous carbon can effectively improve the loading capacity of Se and promote the rapid transfer of ions, but often reduces the spatial confinement of Se species [54,55]. Therefore, the rational design of hierarchically porous carbon materials with precisely controlled pore size distribution represents an optimal strategy for Se-based cathode optimization [56]. For example, Cheng et al. synthesized graphitized hierarchically porous carbon (HPC) through a metallothermic reduction reaction of CO2, which was subsequently compounded with Se to form the HPC/Se composite material [34]. The material provided an ultrahigh specific surface area (1740 m2 g−1) with a hierarchically porous structure comprising micropores, mesopores, and macropores, which can effectively confine Se physically, demonstrating excellent rate capability. Beyond physical confinement, chemical anchoring represents another crucial strategy for inhibiting polyselenide shuttling. As illustrated in Figure 2a, Zhou et al. engineered a three-dimensional “water-cube”-inspired Se/C hybrid material (Se-O-PCS) using Na2CO3 as a structural template [26]. The Se was firmly anchored within the carbon matrix pores through robust Se-O-C chemical bonding, achieving a superior Se content of 51 wt% (Figure 2b). In K-Se batteries, this composite material demonstrated a reversible specific capacity of 624 mAh g−1 at 0.1 A g−1, while maintaining 280 mAh g−1 at 2.0 A g−1, along with exceptional cycling stability (Figure 2c,d). The exceptional rate capability and cycling stability originated from the unique ‘‘water cube” architecture and effective selenium confinement within carbon materials.
Metal–organic frameworks (MOFs) have gained recognition as superior precursors to prepare porous carbon materials [57,58]. These coordination polymers, composed of metal ions and organic linkers, exhibit highly porous carbon networks upon pyrolysis and subsequent metal removal. The resulting architectures effectively encapsulate Se species [59] and retain the desirable morphological characteristics and high surface areas inherent to the parent MOFs [60]. As illustrated in Figure 2f, Huang’s team employed ZIF-67 as a precursor to synthesize nitrogen-doped porous carbon (MDPC) through a sequential carbonization and acid treatment process [35]. Subsequently, the Se/MDPC composite with 53 wt% Se loading was fabricated via the melt-diffusion method. The TEM image displayed in Figure 2e demonstrates that MDPC kept the geometrical polyhedral shape, and Figure 2g shows that the Se had perfectly diffused into the hierarchical pore network of MDPC. As a result, the half-cell delivered discharge capacities of 405, 267, 211, 150, and 101 mAh g−1 at current densities of 0.05 C, 0.1 C, 0.2 C, 0.5 C, and 1 C, respectively, with Coulombic efficiency approaching 90% (Figure 2h). Furthermore, the Se/MDPC cathode delivered a good cyclic stability, which maintained a discharge capacity of ~130 mAh g−1 with Coulombic efficiency exceeding 95% after 100 cycles (Figure 2i). These remarkable electrochemical properties could be ascribed to the hierarchical porous architecture of MDPC, which effectively accommodated the substantial volume expansion of Se (~400%), while nitrogen doping enhanced electronic conductivity and physical confinement inhibited polyselenide shuttling. In a similar approach, Huang, H. et al. fabricated a selenium host material (designated as N-HCNS) by integrating ZIF-8-derived microporous carbon with N-doped porous carbon nanosheets through a melt-diffusion process [37]. This composite architecture effectively inhibited polyselenide shuttle effects, enhanced Se utilization efficiency, and accommodated volume expansions during electrochemical cycling. Comparatively, Sun’s team fabricated interconnected microporous carbon nanorods (denoted as Se@HCR) from Zn-MOF-74, demonstrating superior rate capability due to the enhanced porous architecture [36]. These studies collectively demonstrate the critical role of MOF-derived carbons in addressing the key challenges of Se cathodes, particularly in terms of polyselenide confinement and the accommodation of volume expansion during cycling.
Moreover, alternative carbon-based materials with tailored porosity or heteroatom doping have also demonstrated excellent performance. For instance, the highly efficient nitrogen-doped porous carbon sponge developed by Huang’s team [39] and the N-doped multi-channel carbon nanofibers (h-NMCNFs) fabricated via electrospinning by Lim et al. [24] both significantly improved the performance of potassium–selenium batteries through optimized pore structures. In addition to single-atom doping, Kim’s team developed N, S-co-doped hierarchical porous carbon (denoted as NSHPC) microspheres through spray pyrolysis followed by chemical activation at 650–800 °C (Figure 3a) [38]. As seen in Figure 3c,d, the SEM images of NSHPC-700 and NSHPC-700/Se retain the hierarchical porous architecture. By precisely optimizing the micropore volume and micro/mesopore ratio, the optimized cathode (NSHPC-700/Se) exhibited excellent rate capability. As shown in Figure 3b, NSHPC-700/Se exhibited reversible capacities of 492, 461, 356, 256, and 137 mAh g−1 at the current densities of 0.1 C, 0.2 C, 0.5 C, 1 C, and 2 C, respectively. When the current density decreased to 0.1 C, it still retained a capacity of 482 mAh g−1, showing little capacity decline. Figure 3e shows that the NSHPC-700/Se exhibited an outstanding cycling stability at 0.2 C, demonstrating an excellent reversible capacity of 436 mAh g−1 over 120 cycles. The Coulombic efficiencies stabilized at 98.5% during the initial 20 cycles and consistently exceeded 99% in subsequent cycles. This enhanced performance originates from the substantial micropore volume enabling effective selenium confinement and the precisely tuned micro/mesopore ratio facilitating optimal mass transport. The selenium-filled micropores effectively suppressed polyselenide generation and dissolution through physical confinement, while the interconnected mesoporous network simultaneously enabled efficient electrolyte ion transport and accommodated volumetric fluctuations of selenium during cycling. Furthermore, Zhao’s group proposed a S/O-co-doped porous carbon (SO-HPC) as a high-capacity selenium host material [40]. After selenium melting-diffusion, the Se50/SO-HPC3 composite maintained the original porous morphology (Figure 3f), demonstrating that Se species had thoroughly and homogeneously permeated the micro/mesoporous carbon framework. The composite delivered a reversible capacity of 450 mAh g−1 at 0.5 C after 1700 cycles with a Coulombic efficiency close to 100% (Figure 3g). The improved electrochemical performance can be ascribed to the strong physicochemical synergistic adsorption and immobilization, which effectively inhibited the dissolution of Se anions and mitigated side reactions.

3.1.2. Se/Hollow Carbon Composites

Recently, using hollow nanostructures to modify the positive electrode of K-Se batteries has been widely reported as an innovative method to overcome the performance bottleneck. Firstly, hollow nanostructures can provide more space to alleviate significant volume expansion [7]. Secondly, they exhibit strong chemical binding to polyselenide and provide an effective transport pathway for the movement of ions and electrons [28].
In order to construct this hollow carbon structure, many studies have designed hollow nanostructures by rationally controlling the process of MOFs. For example, Huang et al. reported the synthesis of Se-HPC with porous carbon polyhedrons derived from MOFs via a freeze-drying process and a facile melt-diffusion method [42]. Representing a novel category of engineered structures, MOFs have been widely used in the fields of gas adsorption, separation, and catalysis. As shown in Figure 4a, Zhou’s group built a NO-nanocage/CNT, which was prepared using the solution method to synthesize ZIF-8, adopting zinc nitrate and dimethylimidazole as precursors [28]. First, the polyhedral structure of NO-nanocage/CNT was observed via TEM and SEM, as shown in Figure 4b. Notably, the Se@NO-nanocage/CNT composite demonstrated exceptional rate capability, delivering 304 mAh g−1 at 5 A g−1 with the capacity retained at 80% (380 mAh g−1) at 2 A g−1 (Figure 4c). At the same time, Se@NO-nanocage/CNT demonstrated excellent K storage performance due to its rich micropores and mesopores for efficient K+ capture, N/O co-doping engineering, and superior conductivity. The experimental results have shown that, after 3500 cycles, Se@NO-nanocage/CNT retained an excellent capacity of 274 mAh g−1 (Figure 4d). In order to achieve higher electronic conductivity, which is needed to improve the material’s rate performance, Jia and co-workers successfully fabricated a CFS@N-C using a hollow carbon sphere via a self-assembly method (Figure 4e) [41]. Figure 4f displays the SEM image of CFS@N-C, revealing a uniform hollow carbon sphere structure. At the same time, the CFS@N-C electrode exhibited an optimal cycling ability of up to 500 cycles at a current density of 100 mA g−1 and could maintain a high capacity (Figure 4g). The excellent performance of the CFS@N-C cathode is mainly attributed to the fact that the self-assembled structure resulted in increased K storage performance and structural stability, while maximizing the contact area between the electrode and the electrolyte. In some studies, hollow carbon spheres were directly used to load carbon. Ding et al. reported the synthesis of Se@AHCS via a typical synthesis process. The O-rich functional groups and defective graphitic domains in the carbon matrix provided strong chemisorption sites that effectively immobilized Se intermediates, effectively suppressing polyselenide diffusion [43].

3.1.3. Se/Heteroatom-Doped Carbon Composites

Heteroatom doping is one of the core strategies to enhance the performance of carbon-based materials in cathodes for potassium–selenium batteries. The defect-induced carbon material has a strong adsorption capacity for polyselenide, which can improve the electrochemical performance [7]. In order to alleviate the problems of polyselenide shuttling and significant volume expansion, researchers have proposed single doping to optimize cathode materials. For instance, Park et al. prepared Se-loaded nitrogen single-doped carbon materials (Se@NCHS) with an ordered flower-inspired hierarchical architecture [44].
In addition to single-doped carbon materials, binary-doped carbon-based materials can produce synergistic coupling effects [23,47]. In particular, nitrogen and oxygen heteroatom co-doping has been shown to increase carrier concentration, surface energy, and chemical affinity [46,47]. For example, Yao et al. constructed porous carbon nanosheets interlaced with carbon nanotubes, which were co-doped with N, O (denoted as NOPC-CNT), and encapsulated selenium within them (Se@NOPC-CNT) [23]. Figure 5a details the synthesis of the Se@NOPC-CNT thin-film cathode. The experimental results confirmed the stability of the Se@NOPC-CNT cathode after 700 cycles at 0.8 A g−1. The electrode demonstrated a reversible capacity of 335 mAh g−1 with Coulombic efficiency close to 100% (Figure 5b). As shown in Figure 5c, when the current density was adjusted back to 0.1 A g−1 from 5 A g−1, the capacity reverted to 546 mAh g−1, with almost no attenuation, indicating that the electrode had accelerated reaction kinetics and high stability. The exceptional electrochemical properties could be attributed to the fact that NOPC-CNT had both flexibility and high conductivity, which effectively buffered volume expansion during cycling and strongly adsorbed Se species. In order to enhance the conductivity and reaction kinetics of the electrode, and thus achieve high capacity and long cycle stability, Du et al. used carrageenan and SiO2 as precursors to prepare N/O-co-doped hollow porous carbon (MSTC) via the molten salt method, and then loaded Se via the melt-diffusion method to form a high-efficiency positive electrode material for potassium–selenium batteries [45]. The experimental results showed that the design of a three-dimensional interconnected freestanding carbon film structure endowed the composite material with an excellent conductive network and mechanical stability, showing excellent electrochemical performance. As shown in Figure 5d, the MSTC@Se electrode achieved a rate performance of 507 mAh g−1 at 0.1 A g−1 and maintained a good cycle stability of 201 mAh g−1 after 2000 cycles at a current density of 2 A g−1 (Figure 5e). This can be attributed to the specific design allowing for the high loading (~60 wt%) of selenium by enhancing chemical affinities, due to abundant N and O groups. Furthermore, introducing a N-reinforced O-site on a carbon substance could provide high conductivity and suppress the shuttle effect during cycling. Additionally, Li and co-workers achieved a high-performance flexible potassium–selenium battery by designing N/O-co-doped hierarchical porous carbon nanofibers (denoted as MMCFs) as the host material [46]. The carbon matrix serves as a physical barrier, suppressing the formation of polyselenide and stabilizing the cycling performance.

3.1.4. Se/Biomass-Derived Carbon Composites

The utilization of biomass-derived carbon materials in K-Se batteries has emerged as an increasingly active research area in recent years [61]. Owing to the sustainability, environmental friendliness, and cost-effectiveness of biomass-derived carbon materials, encapsulating Se within porous biochar materials as a cathode for K-Se batteries has garnered increasing attention. Nevertheless, due to their intrinsically limited electrochemical storage capacity, the practical application of biomass-derived carbon materials in K-Se batteries remains a challenge [19,62]. In recent investigations, researchers have engineered biomass-derived carbons with diverse structures and compositions to inhibit the polyselenide shuttle effect, alleviate volume expansion, and enhance conductivity of K-Se batteries [25].
Biomass-derived porous carbon-based materials are widely employed as Se hosts within cathode architectures. Recently, Ma and co-workers designed a biomass-derived 3D N-doped cross-linked porous carbon (3D-N-CPC) as a Se host for the cathode, which was synthesized from eggplant biomass through a freeze-drying and pyrolysis process (Figure 6a) [48]. The material had an abundance of hierarchical three-dimensional microporous structures. After Se infiltration, the 3D-N-CPC retained its original three-dimensional framework, while the Se element was uniformly permeated throughout the interconnected pore channels (Figure 6b,c). Qiu et al. synthesized an interconnected foam-like N-doped porous carbon (FNDPC) from natural cotton to serve as a Se host for the cathode (Figure 6d,e) [29], thereby offering a viable strategy for the advancement of low-cost Se-based cathode materials. Moreover, several researchers have further advanced cathode performance by co-incorporating biochar with graphene or analogous carbonaceous scaffolds to jointly act as the Se host. For example, Cai et al. reported a novel cathode material called PC/Se/GO, fabricated by combining porous biochar derived from walnut shells with graphene oxide (GO) [49]. The composite exhibited an irregular cubic morphology (Figure 6f). This structure markedly improved both capacity and cycling stability, with PC/Se/GO exhibiting a reversible capacity of 426.3 mAh g−1 in the second cycle (Figure 6g). This can be attributed to the uniform dispersion of selenium within PC/Se domains.

3.1.5. Small-Molecular Se/Carbon Composites

Small-molecule Se has recently received much attention in view of its high specific surface area and size effect, which lead to small-molecule Se-based cathodes with high specific capacity and high ionic conductivity [19]. To enhance the energy density and cycle life of batteries, researchers compounded small molecules of Se with carbon-based materials (such as porous carbon nanofibers and bio-derived carbon) [30].
For example, Xu et al. prepared a flexible potassium–selenium battery by using small-molecule selenium embedded in freestanding thin-film N-doped porous carbon nanofibers (Se@NPCFs) as the cathode (Figure 7a) [30], which had a unique pod-like morphology with abundant pores. The Se@NPCFs resulted in a superior capacity retention of 367 mAh g−1 at 0.5 A g−1 over 1670 cycles with Columbic efficiency close to 100% (Figure 7b). These superior electrochemical properties can be ascribed to the pea pod-like 1D N-doped porous carbon nanofiber structure, which promoted electrolyte permeation and K+ diffusion, buffered volume expansion, and reduced electrical resistance. In order to enhance the cycling stability of cathode materials, Wang et al. introduced small-molecule Se to the natural nanoscale pores of N/S-co-doped walnut shell-derived biomass carbon using a two-step carbonization method and melt-diffusion method (Figure 7c) [50]. As seen in Figure 7d, the capacity of Se@PWC-NS remained at 211.7 mAh g−1 after 3500 cycles. This enhanced performance originated from the use of N/S-co-doped walnut shell-derived carbon as a selenium carrier, which inhibited Se volume expansion and improved electrochemical stability. Furthermore, carbon-based material derivatives have also been used to reinforce small-molecule Se cathodes [13].

3.2. Engineering Chemisorptive Hosts

Another strategy to improve the stability of Se-based cathode materials is to design chemisorptive hosts [63,64]. Chemisorptive hosts can construct strong chemical interaction sites with Se/polyselenide by modulating the chemical composition of carbon or surface functional groups. This strategy could inhibit the dissolution and shuttle effect of polyselenide, enhance the binding of Se to the carbon hosts, and reduce the loss of Se species during charging and discharging [19].
Among many applications of engineering chemisorptive hosts, Wu et al. designed novel dual-wall hollow carbon spheres (DWHCSs) optimized with cetyltrimethylammonium bromide (CTAB) to serve as a selenium host material (C-DWHCSs) for constructing the selenium cathode (C-DWHCSs/Se) (Figure 7e) [31]. The C-DWHCSs/Se exhibited a double-walled hollow structure with a high specific surface area, enabling strong polyselenide adsorption and thus greatly improving the loading capacity of the Se cathode. The C-DWHCSs/Se cathode exhibited an excellent capacity of 411 mAh g−1 at 0.1 C after 100 cycles (Figure 7f). The enhanced cycling performance can be ascribed to the large specific surface area and hollow structure of DWHCSs, which provided ample loading space for Se species and significantly increased the Se loading. In addition, the natural buffer space of the double-wall gap could accommodate the volume expansion of Se during cycling. Furthermore, Yang et al. introduced a polar material, MoSe2, into chitosan-derived hierarchical porous carbon (MoSe2-HPC) via a simple freeze-drying carbonization method, with this material used as a host material of Se [51], exhibiting remarkable cycling and rate performance. These studies demonstrate the great potential of chemisorptive hosts for improving the performance of Se-based cathodes.

3.3. Electrocatalysis of Redox Reactions

In addition to the above strategies, in recent years, researchers have begun to introduce catalysts to enhance the adsorption and transformation of polyselenide [52]. Studies have shown that the cycling stability and rate performance of K-Se batteries are significantly improved by synthesizing different materials design strategies on the basis of carbon materials and introducing a porous structure and an electrocatalyst. These studies provide an important theoretical and experimental basis to achieve high-performance K-Se batteries [32,52,53].
On the one hand, Cho et al. prepared a one-dimensional N-doped carbon framework (denoted as P-N-C@Mo2C) via electrospinning, carbonization, and KOH activation, and applied it to the infiltration of Se (Se@P-N-C@Mo2C), as shown in Figure 8a [32]. P-N-C@Mo2C showed a 1D porous structure, and the subsequently formed Se@P-N-C@Mo2C also exhibited a similar structure (Figure 8b,c). The porous structure was helpful for electrolyte penetration and electron/ion diffusion, reducing diffusion distance and adapting to volume expansion. The N doping improved the electronic conductivity of the carbon frame, and the ultrafine Mo2C catalyst could effectively capture and electrocatalytically transform potassium–selenides through electrophilic coupling interaction with Mo and Se, thus improving the utilization rate of active materials.
Chemical adsorption and electrocatalysis are also frequently combined. Zhou et al. developed a Se-W2N/C composite by employing melt-diffusion to achieve uniform Se distribution throughout the W2N/C porous carbon structure [53]. This design not only utilizes the catalytic performance of W2N, but also uses the adsorption performance of porous carbon. Considering that the porous carbon matrix had a micropore structure (Figure 8d), the material exhibited enough space for Se species, which effectively alleviated the volume expansion of Se during cycling. Therefore, as seen in Figure 8e, the Se-W2N/C exhibited a capacity of 286 mAh g−1 after 500 cycles at 1 A g−1. The superior electrochemical performance could be ascribed to the fact that W2N can adsorb Se species and inhibit the dissolution and shuttling of polyselenide in the electrolyte due to its high conductivity and chemical polarity. Moreover, W2N had a bidirectional catalytic effect in the K-Se battery, which can promote the redox reaction of Se.

3.4. Summary

Encapsulating Se within carbon materials is an effective strategy to improve the performance of K-Se batteries. By using the high electrical conductivity, adjustable pore structures, and large specific surface area of carbon materials, this approach significantly improves electron transfer efficiency and reaction kinetics of Se, while effectively suppressing polyselenide dissolution and shuttle effects, as well as mitigating volume expansion of selenium during charge/discharge processes [7]. Commonly employed carbon hosts include porous carbon, hollow carbon, heteroatom-doped carbon, biomass-derived carbon, and small-molecule Se/C composite systems [19]. Each type offers distinct advantages: porous carbon efficiently accommodates volume changes in selenium and facilitates ion transport [34]; hollow carbon enhances polyselenide confinement through its enclosed structure [42]; heteroatom-doped carbon improves chemisorption and conductivity via defect sites [47]; biomass-derived carbon combines sustainability with low cost [48]; and small-molecule Se/C composites promote reaction kinetics due to size effects [30]. Nevertheless, this method exhibits notable limitations: the melt-diffusion process often leads to uneven selenium distribution within the carbon matrix, reducing active material utilization [35]; MOF-derived carbon and heteroatom-doped carbon involve complex and costly synthesis, hindering large-scale production [36]; biomass-derived carbon typically exhibits low intrinsic electrochemical capacity and requires additional modification [48]; and small-molecule selenium suffers from poor storage stability and tends to agglomerate over time [30]. Moreover, the physical confinement capability of carbon materials is significantly compromised under high selenium loading [19].
Engineering chemisorptive hosts is necessary to construct a strong chemical interaction site with selenium/polyselenide by regulating the chemical composition or surface functional groups of carbon materials, so as to break through the limitation of simple physical confinement and realize the efficient anchoring of polyselenide. The strong binding of Se can improve the cycle stability and active material utilization of the battery [31]. However, its limitations are as follows: the number and strength of chemical adsorption sites are difficult to accurately regulate; excessive doping or composite polar materials can easily lead to a decrease in the conductivity of carbon materials; and the chemical adsorption sites are easily saturated under high selenium loading, which cannot effectively inhibit the shuttling of polyselenide [51]. The synthesis steps of the introduced additional components are usually more complicated and costly, which is not conducive to large-scale applications. In addition, the dynamic evolution of the adsorption mechanism in the actual battery operating environment, and the stability and failure behavior in the long-term cycle still lack in situ research, and the sustainability of the chemical adsorption efficiency needs to be verified [19].
The introduction of electrocatalysts into K-Se batteries to enhance the adsorption and conversion of polyselenide represents an emerging research direction. By designing carbon-based composite structures incorporating porous architectures and electrocatalytic sites, the cycling stability and rate capability of the batteries can be significantly improved [19]. This approach offers the advantage of effectively lowering the energy barrier of Se conversion reactions and accelerating the redox kinetics, thereby enhancing the overall battery performance [52]. However, strategies for electrocatalysis of redox reactions also face several limitations. For instance, catalyst nanoparticles are prone to agglomeration and may detach during long-term cycling due to weak interfacial bonding, leading to degradation of catalytic activity. Moreover, the synthesis processes often rely on high-temperature reduction or complex procedures, which are costly and yield low production efficiency. Most importantly, the underlying catalytic mechanisms remain insufficiently understood, and the lack of in situ characterization of intermediate polyselenide species hinders precise optimization of catalyst performance [32,53]. Therefore, it is imperative to develop low-cost, highly stable catalysts and to deepen mechanism research to promote practical applications.

4. Conclusions and Outlook

In summary, this review provides comprehensive elaboration on carbon-based cathodes for potassium–selenium batteries, including strategies such as encapsulating Se within carbon materials, engineering chemisorptive hosts, and electrocatalyzing redox reactions. It details how these materials enhance electronic conductivity, buffer volume expansion, and inhibit the shuttle effects of polyselenide through various mechanisms. Carbon-based materials demonstrate multiple inherent advantages for improving the electrochemical properties of potassium–selenium batteries. Firstly, they have adjustable pores and large surface areas, which can effectively confine Se and alleviate volume expansion. Secondly, they can offer efficient electron transport to accelerate Se redox kinetics. Thirdly, heteroatom-doped carbon materials could anchor polyselenide, inhibiting the shuttle effect. Although many studies have explored the cathode materials of K-Se batteries, there are still some existing challenges that remain to be solved. Some suggestions to further enhance the electrochemical performance of carbon-based materials in cathodes for K-Se batteries are presented (Figure 9):
  • Mechanism exploration. In K-Se battery cathodes, carbon-based materials are primarily used as Se host matrices, conductive frameworks, and polyselenide adsorption media, effectively enhancing battery performance through synergistic physical confinement, chemical anchoring, and conductivity enhancement mechanisms. Nevertheless, current studies do not clearly establish the quantitative relationship between carbon pore structures and selenium loading capacity, the differential adsorption energies of polyselenide at heteroatom doping sites, and the mechanistic links between Se phase transition pathways (particularly intermediate states during Se8 to K2Se conversion) and the structural stability of carbon-based materials. Therefore, it is imperative to employ in situ characterization techniques (e.g., in situ XRD and Raman spectra) to track the evolution of Se species and polyselenide, combined with theoretical simulations (such as density functional theory calculations of adsorption energies) [65,66], to illustrate the dynamic interactions between carbon-based materials and Se, thereby providing a foundation for designing high-performance materials.
  • Novel composite materials. Currently, the applications of carbon-based materials in cathodes for potassium-selenium batteries primarily include Se/porous carbon composites, Se/heteroatom-doped carbon composites, Se/hollow carbon composites, and Se/biomass-derived carbon composites. Although current carbon-based materials exhibit substantial diversity and have successfully elevated battery performance, the development of novel carbon composite materials is still essential for achieving superior electrochemical properties. For instance, the hybridization of carbon materials with graphene, metal-based materials (e.g., MOFs and MXenes), and carbides or nitrides enables the fabrication of carbon materials with enhanced electrochemical activity. Moreover, using artificial intelligence (AI) to accelerate the selection of high-performance materials has emerged as a leading frontier in the field [66]. These novel composite materials can simultaneously provide efficient ion/electron transport pathways and effectively inhibit polyselenide shuttling via chemical anchoring, thereby significantly enhancing overall stability. Furthermore, through precise morphological control, further performance optimization can be achieved, endowing these materials with significant potential for future applications.
  • Advanced synthesis methods. The melt-diffusion method has been widely adopted for preparing Se/carbon composites due to its operational simplicity, cost-effectiveness, and scalability for large-scale production. The uniformity and loading capacity of Se can be significantly enhanced through precise regulation of the porous structure of the carbon host and optimization of the melt-diffusion temperature. Recently, researchers have proposed some effective ways to optimize the melt-diffusion method. For example, microwave-assisted melting significantly reduces both the reaction duration and Se volatilization. Another approach is template-guided melting, which demonstrates considerable potential by enhancing confinement effects through predesigned pore architectures. Furthermore, the development of novel carbon-based composites will significantly advance their synthetic applications and performance optimization. Beyond the melt-diffusion method, alternative synthetic approaches including electrospinning have been systematically investigated. Comprehensively evaluating the advantages and limitations of different methods and selecting the optimal strategy are expected to drive significant progress in the application of carbon-based materials for K-Se batteries.
  • Promising applications. With the advancement of flexible energy storage technologies, potassium–selenium batteries are expected to become a new focus in portable and wearable electronic devices due to their excellent energy density and low-cost K resource advantages. By constructing a self-supporting flexible cathode in the carbon framework, the excellent flexibility and conductivity of carbon materials can be efficiently used to provide high endurance power for thin wearable and foldable-screen devices. Notably, in view of the fact that the ionic conductivity of the K-Se battery is less affected by low temperature, the system can be applied to wearable monitoring equipment in extreme low-temperature conditions. Therefore, with the continuous progress in the preparation technologies of carbon-based cathode materials, flexible potassium–selenium batteries are expected to reach large-scale production and further accelerate the commercial advancement of wearable electronics. Moreover, K-Se batteries could be coupled with energy harvesting technologies (such as capturing biomechanical and environmental energy), and K-Se batteries can greatly extend the runtime of wearable biometric sensors and other sustainable devices. This integration could enhance functionality and reliability while providing sustainability and energy efficiency. As carbon-based cathode materials advance, scalable production of flexible K-Se batteries is expected, accelerating the commercialization of next-generation wearable technology and promoting a more sustainable future.
Ultimately, this review systematically outlines recent advances in carbon-based materials in cathodes for K-Se batteries. However, several critical challenges, as discussed above, still require further optimization and resolution. We firmly believe that through the persistent efforts of researchers, these challenges will ultimately be overcome, which will contribute to breakthroughs in the design and development of novel Se/carbon composites. This review provides valuable insights and facilitates the application of carbon-based materials for K-Se batteries and other emerging energy storage systems.

Author Contributions

Conceptualization, methodology, J.W., Y.L. (Yanfang Liang), D.G. and C.L.; validation, J.W., Z.S. and X.T.; investigation, J.W., X.S. and Y.L. (Yanfang Liang); writing—original draft preparation, J.W.; writing—review and editing, J.W., X.S. and Y.L. (Yong Liu); funding acquisition, J.W. and Y.L. (Yong Liu). Project administration, X.S.; Supervision, Y.L. (Yong Liu). All authors have read and agreed to the published version of the manuscript.

Funding

This work was financially supported by the Student Research Training Plan of Henan University of Science and Technology (2024054, 2025049).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

No new data were created or analyzed in this study.

Acknowledgments

The authors sincerely thank Yong Liu for his insightful discussions in this research. His expertise and dedication in shaping the conceptual framework were pivotal to the realization of this work. We are deeply grateful for his contribution to enriching the depth of this study.

Conflicts of Interest

The authors declare no conflicts of interest. Xiaobin Sun: “I hereby disclose my conflict of interest as outlined by the MDPI guidelines. I am currently employed by China Lithium Battery Technology (Luoyang) Co., Ltd. while contributing to this manuscript. My contributions to this work and manuscript were made independently without any requirement, guidance or input by my employer. I received no financial compensation from any source for the contributions I made to this scientific work and manuscript”.

References

  1. Goodenough, J.B.; Kim, Y. Challenges for Rechargeable Li Batteries. Chem. Mater. 2010, 22, 587–603. [Google Scholar] [CrossRef]
  2. Rangarajan, S.S.; Sunddararaj, S.P.; Sudhakar, A.; Shiva, C.K.; Subramaniam, U.; Collins, E.R.; Senjyu, T. Lithium-Ion Batteries—The Crux of Electric Vehicles with Opportunities and Challenges. Clean Technol. 2022, 4, 908–930. [Google Scholar] [CrossRef]
  3. Yao, Q.; Zhu, C. Advanced Post-Potassium-Ion Batteries as Emerging Potassium-Based Alternatives for Energy Storage. Adv. Funct. Mater. 2020, 30, 2005209. [Google Scholar] [CrossRef]
  4. Scrosati, B.; Garche, J. Lithium batteries: Status, prospects and future. J. Power Sources 2010, 195, 2419–2430. [Google Scholar] [CrossRef]
  5. Wu, N.; Shen, J.; Li, Q.; Li, S.; Guo, D.; Li, J.; Liu, G.; Zhao, J.; Cao, A.; Mi, H.; et al. Synergistic Bimetallic Interaction and Regulated Void Size in Isocubanite CuFe2S3 Enables UltraFast and Durable Sodium Storage. ACS Sustain. Chem. Eng. 2025, 13, 5546–5556. [Google Scholar] [CrossRef]
  6. Liu, Y.-H.; Wang, F.; Wang, H.-B.; Kong, C.-Y.; Wang, G.-X.; Liu, X.-M.; Liu, Y. Shining light on fillers uniform dispersion of PVDF/garnet composite electrolytes for high-performance solid-state Li batteries: Fundamentals, progress and perspectives. Rare Met. 2025, 44, 5957–5979. [Google Scholar] [CrossRef]
  7. Huang, X.; Sun, J.; Wang, L.; Tong, X.; Dou, S.X.; Wang, Z.M. Advanced High-Performance Potassium-Chalcogen (S, Se, Te) Batteries. Small 2021, 17, 2004369. [Google Scholar] [CrossRef]
  8. Zheng, J.; Wu, Y.; Sun, Y.; Rong, J.; Li, H.; Niu, L. Advanced Anode Materials of Potassium Ion Batteries: From Zero Dimension to Three Dimensions. Nano-Micro Lett. 2020, 13, 12. [Google Scholar] [CrossRef]
  9. Eftekhari, A.; Jian, Z.; Ji, X. Potassium Secondary Batteries. ACS Appl. Mater. Interfaces 2017, 9, 4404–4419. [Google Scholar] [CrossRef]
  10. Kim, H.C.; Kim, H.; Moon, S.O.; Jo, C.; Park, H.S. Carbon-based materials for potassium-ion battery anodes: Storage mechanisms and engineering strategies. J. Energy Chem. 2025, 105, 764–796. [Google Scholar] [CrossRef]
  11. Deng, Q.; Pei, J.; Fan, C.; Ma, J.; Cao, B.; Li, C.; Jin, Y.; Wang, L.; Li, J. Potassium salts of para-aromatic dicarboxylates as the highly efficient organic anodes for low-cost K-ion batteries. Nano Energy 2017, 33, 350–355. [Google Scholar] [CrossRef]
  12. Zhang, W.; Liu, Y.; Guo, Z. Approaching high-performance potassium-ion batteries via advanced design strategies and engineering. Sci. Adv. 2019, 5, eaav7412. [Google Scholar] [CrossRef]
  13. Liu, Y.; Tai, Z.; Zhang, Q.; Wang, H.; Pang, W.K.; Liu, H.K.; Konstantinov, K.; Guo, Z. A new energy storage system: Rechargeable potassium-selenium battery. Nano Energy 2017, 35, 36–43. [Google Scholar] [CrossRef]
  14. Liu, Q.; Deng, W.; Pan, Y.; Sun, C.-F. Approaching the voltage and energy density limits of potassium–selenium battery chemistry in a concentrated ether-based electrolyte. Chem. Sci. 2020, 11, 6045–6052. [Google Scholar] [CrossRef]
  15. Liang, Y.; Liu, H.; Wang, G.; Wang, C.; Ni, Y.; Nan, C.-W.; Fan, L.-Z. Challenges, interface engineering, and processing strategies toward practical sulfide-based all-solid-state lithium batteries. InfoMat 2022, 4, e12292. [Google Scholar] [CrossRef]
  16. Lee, S.; Lee, J.; Kim, J.; Agostini, M.; Xiong, S.; Matic, A.; Hwang, J.-Y. Recent Developments and Future Challenges in Designing Rechargeable Potassium-Sulfur and Potassium-Selenium Batteries. Energies 2020, 13, 2791. [Google Scholar] [CrossRef]
  17. Park, J.; Kim, H.; Celeste, A.; Park, H.; Kansara, S.; Zumpano, R.; Piacentini, V.; Brutti, S.; Matic, A.; Agostini, M.; et al. Prospects of Alkali Metal–Se Batteries and Beyond: From Redox Mechanisms to Electrode Design. ACS Energy Lett. 2025, 10, 2512–2531. [Google Scholar] [CrossRef]
  18. Zhou, X.; Rui, X.; Yu, Y. High Energy Density Na (K)-Se Batteries: Some Challenges and Potential Solutions. Acc. Mater. Res. 2023, 4, 467–471. [Google Scholar] [CrossRef]
  19. Huang, X.L.; Guo, Z.; Dou, S.X.; Wang, Z.M. Rechargeable Potassium-Selenium Batteries. Adv. Funct. Mater. 2021, 31, 2102326. [Google Scholar] [CrossRef]
  20. Li, H.; Dong, W.; Li, C.; Barakat, T.; Sun, M.; Wang, Y.; Wu, L.; Wang, L.; Xia, L.; Hu, Z.-Y.; et al. Three-dimensional ordered hierarchically porous carbon materials for high performance Li-Se battery. J. Energy Chem. 2022, 68, 624–636. [Google Scholar] [CrossRef]
  21. Liu, H.; Wang, Q.; Sun, X.; Gou, H.; Zhang, C.; Wang, G. Carbon host pore structure regulation boosting fast and stable Se-K electrochemistry towards Se-K ion capacitors. Carbon 2023, 203, 141–151. [Google Scholar] [CrossRef]
  22. Gao, Y.-M.; Liu, Y.; Feng, K.-J.; Ma, J.-Q.; Miao, Y.-J.; Xu, B.-R.; Pan, K.-M.; Akiyoshi, O.; Wang, G.-X.; Zhang, K.-K.; et al. Emerging WS2/WSe2@graphene nanocomposites: Synthesis and electrochemical energy storage applications. Rare Met. 2024, 43, 1–19. [Google Scholar] [CrossRef]
  23. Yao, Y.; Chen, M.; Xu, R.; Zeng, S.; Yang, H.; Ye, S.; Liu, F.; Wu, X.; Yu, Y. CNT Interwoven Nitrogen and Oxygen Dual-Doped Porous Carbon Nanosheets as Free-Standing Electrodes for High-Performance Na-Se and K-Se Flexible Batteries. Adv. Mater. 2018, 30, 1805234. [Google Scholar] [CrossRef]
  24. Lim, J.B.; Kim, H.J.; Na, J.H.; Kim, J.K.; Jeong, S.-Y.; Park, S.-K. Hierarchical nitrogen-doped multichannel carbon nanofibers for efficient potassium-selenium batteries. Rare Met. 2025, 44, 3839–3851. [Google Scholar] [CrossRef]
  25. Du, Y.; Ma, S.; Dai, J.; Lin, J.; Zhou, X.; Chen, T.; Gu, X. Biomass Carbon Materials Contribute Better Alkali-Metal-Selenium Batteries: A Mini-Review. Batteries 2022, 8, 123. [Google Scholar] [CrossRef]
  26. Zhou, L.; Cui, Y.; Kong, D.; Feng, W.; Gao, X.; Yan, Y.; Ren, H.; Hu, H.; Xue, Q.; Yan, Z.; et al. Amorphous Se species anchored into enclosed carbon skeleton bridged by chemical bonding toward advanced K-Se batteries. J. Energy Chem. 2021, 61, 319–326. [Google Scholar] [CrossRef]
  27. Khan, M.; Ding, X.; Zhao, H.; Wang, Y.; Zhang, N.; Chen, X.; Xu, J. Recent Advancements in Selenium-Based Cathode Materials for Lithium Batteries: A Mini-Review. Electrochem 2022, 3, 285–308. [Google Scholar] [CrossRef]
  28. Zhou, X.; Wang, L.; Yao, Y.; Jiang, Y.; Xu, R.; Wang, H.; Wu, X.; Yu, Y. Integrating Conductivity, Captivity, and Immobility Ability into N/O Dual-Doped Porous Carbon Nanocage Anchored with CNT as an Effective Se Host for Advanced K-Se Battery. Adv. Funct. Mater. 2020, 30, 2003871. [Google Scholar] [CrossRef]
  29. Qiu, R.; Fei, R.; Zhang, T.; Liu, X.; Jin, J.; Fan, H.; Wang, R.; He, B.; Gong, Y.; Wang, H. Biomass-derived, 3D interconnected N-doped carbon foam as a host matrix for Li/Na/K-selenium batteries. Electrochim. Acta 2020, 356, 136832. [Google Scholar] [CrossRef]
  30. Xu, R.; Yao, Y.; Wang, H.; Yuan, Y.; Wang, J.; Yang, H.; Jiang, Y.; Shi, P.; Wu, X.; Peng, Z.; et al. Unraveling the Nature of Excellent Potassium Storage in Small-Molecule Se@Peapod-Like N-Doped Carbon Nanofibers. Adv. Mater. 2020, 32, 2003879. [Google Scholar] [CrossRef]
  31. Wu, X.; Chen, X.; Wu, H.; Xie, B.; Wang, D.; Wang, R.; Zhang, X.; Piao, Y.; Diao, G.; Chen, M. Encapsulation of Se in dual-wall hollow carbon spheres: Physical confinement and chemisorption for superior Na-Se and K-Se batteries. Carbon 2022, 187, 354–364. [Google Scholar] [CrossRef]
  32. Cho, S.W.; Choi, H.H.; Senthamaraikannan, T.G.; Lim, D.-H.; Park, G.D.; Cho, C.; Jeong, S.M.; Saroha, R.; Cho, J.S. Hierarchical porous one-dimensional N-doped C framework comprising ultrafine Mo2C catalysts for stable Na/K-Se batteries: Experimental and theoretical investigations. Chem. Eng. J. 2025, 512, 162456. [Google Scholar] [CrossRef]
  33. Zeng, L.; Zeng, W.; Jiang, Y.; Wei, X.; Li, W.; Yang, C.; Zhu, Y.; Yu, Y. A Flexible Porous Carbon Nanofibers-Selenium Cathode with Superior Electrochemical Performance for Both Li-Se and Na-Se Batteries. Adv. Energy Mater. 2015, 5, 1401377. [Google Scholar] [CrossRef]
  34. Cheng, L.; Ma, C.; Lu, W.; Wang, X.; Yue, H.; Zhang, D.; Xing, Z. A graphitized hierarchical porous carbon as an advanced cathode host for alkali metal-selenium batteries. Chem. Eng. J. 2022, 433, 133527. [Google Scholar] [CrossRef]
  35. Huang, X.; Xu, Q.; Gao, W.; Yang, T.; Zhan, R.; Deng, J.; Guo, B.; Tao, M.; Liu, H.; Xu, M. Rechargeable K-Se batteries based on metal-organic-frameworks-derived porous carbon matrix confined selenium as cathode materials. J. Colloid Interface Sci. 2019, 539, 326–331. [Google Scholar] [CrossRef]
  36. Sun, Y.; Liao, J.; Sun, J.; Duan, L.; Du, Y.; Bao, J.; Zhou, X. Zn-MOF-74-Derived Carbon Nanorods as an Efficient Se Host for K-Se Batteries. ACS Appl. Energy Mater. 2022, 5, 13023–13030. [Google Scholar] [CrossRef]
  37. Huang, H.; Luo, X.; Yao, Y.; Zhou, X.; Jiang, Y.; Guo, C.; Liu, J.; Wu, X.; Yu, Y. Binding Se into nitrogen-doped porous carbon nanosheets for high-performance potassium storage. InfoMat 2021, 3, 421–431. [Google Scholar] [CrossRef]
  38. Kim, J.K.; Kang, Y.C. Encapsulation of Se into Hierarchically Porous Carbon Microspheres with Optimized Pore Structure for Advanced Na-Se and K-Se Batteries. ACS Nano 2020, 14, 13203–13216. [Google Scholar] [CrossRef]
  39. Huang, X.; Deng, J.; Qi, Y.; Liu, D.; Wu, Y.; Gao, W.; Zhong, W.; Zhang, F.; Bao, S.; Xu, M. A highly-effective nitrogen-doped porous carbon sponge electrode for advanced K-Se batteries. Inorg. Chem. Front. 2020, 7, 1182–1189. [Google Scholar] [CrossRef]
  40. Zhao, X.; Yin, L.; Yang, Z.; Chen, G.; Yue, H.; Zhang, D.; Sun, Z.; Li, F. An alkali metal-selenium battery with a wide temperature range and low self-discharge. J. Mater. Chem. A 2019, 7, 21774–21782. [Google Scholar] [CrossRef]
  41. Jia, X.-X.; Yu, X.-Z.; Lu, B.-A. Fe0.8CoSe2 nanosphere coated by N-doped carbon for ultra-high rate potassium selenium battery. Rare Met. 2021, 40, 2455–2463. [Google Scholar] [CrossRef]
  42. Huang, X.; Wang, W.; Deng, J.; Gao, W.; Liu, D.; Ma, Q.; Xu, M. A Se-hollow porous carbon composite for high-performance rechargeable K-Se batteries. Inorg. Chem. Front. 2019, 6, 2118–2125. [Google Scholar] [CrossRef]
  43. Ding, J.; Wang, Y.; Huang, Z.; Song, W.; Zhong, C.; Ding, J.; Hu, W. Toward Theoretical Capacity and Superhigh Power Density for Potassium-Selenium Batteries via Facilitating Reversible Potassiation Kinetics. ACS Appl. Mater. Interfaces 2022, 14, 6828–6840. [Google Scholar] [CrossRef] [PubMed]
  44. Kim, H.-J.; Na, J.-H.; Park, S.-K. Monodisperse Hierarchical N-Doped Carbon Microspheres with Uniform Pores as a Cathode Host for Advanced K-Se Batteries. Batteries 2025, 11, 101. [Google Scholar] [CrossRef]
  45. Du, Y.; Fan, H.; Zhu, Y.; Zhang, X.; Wei, D.; Jin, C.; Cui, Y.; Lv, M. Anchoring active sulfur/selenium into enhanced carbon hosts with multiple chemical affinities for efficient K-S/Se batteries. Green Chem. 2025, 27, 2309–2318. [Google Scholar] [CrossRef]
  46. Li, D.; Wang, L.; Cheng, X.; Yao, Y.; Jiang, Y.; Shi, P.; Wu, Y.; Wu, X.; Ma, C.; Yu, Y. Manipulating selenium molecular configuration in N/O dual-doped porous carbon for high performance potassium-ion storage. J. Energy Chem. 2021, 62, 581–589. [Google Scholar] [CrossRef]
  47. Zhao, X.; Wang, D.; Qi, H.; Li, Z.; Yue, H. N/O-doped porous carbon matrix for improved potassium-selenium battery cathode in different electrolyte systems. J. Alloys Compd. 2023, 930, 167395. [Google Scholar] [CrossRef]
  48. Ma, Q.; Chen, S.; Li, Y.; Yan, Z.; Liu, Y.; Fang, Z. Encapsulating Selenium into Biomass-Derived Nitrogen-Doped Porous Carbon As the Cathode for Sodium-Selenium and Potassium-Selenium Batteries. ACS Appl. Nano Mater. 2024, 7, 16599–16608. [Google Scholar] [CrossRef]
  49. Cai, R.; Chen, X.; Liu, P.; Chen, T.; Liu, W.; Fan, X.; Ouyang, B.; Liu, K. A Novel Cathode Based on Selenium Confined in Biomass Carbon and Graphene Oxide for Potassium-Selenium Battery. ChemElectroChem 2020, 7, 4477–4483. [Google Scholar] [CrossRef]
  50. Wang, H.; Wang, P.; Cao, J.; Liang, C.; Yu, K. N/S co-doped biomass-based porous carbon surface-embedded small-molecule selenium as cathode circumflex accent A for high-performance K-Se batteries. Electrochim. Acta 2022, 432, 141158. [Google Scholar] [CrossRef]
  51. Yang, W.; Jamil, S.; Xu, M. Hierarchical Porous Carbon Embedded MoSe2 Effectively Improve Cycle Stability in K-Se Battery. ChemistrySelect 2023, 8, e202300470. [Google Scholar] [CrossRef]
  52. Ding, Y.; Cai, J.; Sun, Y.; Shi, Z.; Yi, Y.; Liu, B.; Sun, J. Bimetallic Selenide Decorated Nanoreactor Synergizing Confinement and Electrocatalysis of Se Species for 3D-Printed High-Loading K-Se Batteries. ACS Nano 2022, 16, 3373–3382. [Google Scholar] [CrossRef]
  53. Zhou, L.; Li, B.; Hu, H.; Liu, H.; Nan, J.; Wu, W.; Xu, H.; Cai, T.; Liu, P.; Li, X.; et al. Regulating Redox Kinetics by a W2N Electrocatalyst toward High-Performance K-Se Batteries. Energy Fuels 2023, 37, 18103–18110. [Google Scholar] [CrossRef]
  54. He, J.; Lv, W.; Chen, Y.; Xiong, J.; Wen, K.; Xu, C.; Zhang, W.; Li, Y.; Qin, W.; He, W. Three-dimensional hierarchical C-Co-N/Se derived from metal-organic framework as superior cathode for Li-Se batteries. J. Power Sources 2017, 363, 103–109. [Google Scholar] [CrossRef]
  55. Wu, T.; Ding, Z.; Jing, M.; Zou, G.; Hou, H.; Tian, Y.; Jiang, Y.; Hong, W.; Ji, X. Chem-Bonding and Phys-Trapping Se Electrode for Long-Life Rechargeable Batteries. Adv. Funct. Mater. 2019, 29, 1809014. [Google Scholar] [CrossRef]
  56. Li, F.; Zhou, Z. Micro/Nanostructured Materials for Sodium Ion Batteries and Capacitors. Small 2018, 14, 1702961. [Google Scholar] [CrossRef]
  57. Xu, Q.; Yang, T.; Gao, W.; Zhan, R.; Zhang, Y.; Bao, S.; Li, X.; Chen, Y.; Xu, M. Jackfruit-like electrode design for advanced Na-Se batteries. J. Power Sources 2019, 443, 227245. [Google Scholar] [CrossRef]
  58. Xu, Q.; Liu, T.; Li, Y.; Hu, L.; Dai, C.; Zhang, Y.; Li, Y.; Liu, D.; Xu, M. Selenium Encapsulated into Metal–Organic Frameworks Derived N-Doped Porous Carbon Polyhedrons as Cathode for Na–Se Batteries. ACS Appl. Mater. Interfaces 2017, 9, 41339–41346. [Google Scholar] [CrossRef]
  59. Dong, W.; Chen, H.; Xia, F.; Yu, W.; Song, J.; Wu, S.; Deng, Z.; Hu, Z.-Y.; Hasan, T.; Li, Y.; et al. Selenium clusters in Zn-glutamate MOF derived nitrogen-doped hierarchically radial-structured microporous carbon for advanced rechargeable Na–Se batteries. J. Mater. Chem. A 2018, 6, 22790–22797. [Google Scholar] [CrossRef]
  60. Zhang, S.; Yang, D.; Tan, H.; Feng, Y.; Rui, X.; Yu, Y. Advances in K-Q (Q = S, Se and SexSy) batteries. Mater. Today 2020, 39, 9–22. [Google Scholar] [CrossRef]
  61. Luo, C.; Xu, Y.; Zhu, Y.; Liu, Y.; Zheng, S.; Liu, Y.; Langrock, A.; Wang, C. Selenium@Mesoporous Carbon Composite with Superior Lithium and Sodium Storage Capacity. ACS Nano 2013, 7, 8003–8010. [Google Scholar] [CrossRef]
  62. Huang, X.L.; Zhou, C.; He, W.; Sun, S.; Chueh, Y.-L.; Wang, Z.M.; Liu, H.K.; Dou, S.X. An Emerging Energy Storage System: Advanced Na-Se Batteries. ACS Nano 2021, 15, 5876–5903. [Google Scholar] [CrossRef] [PubMed]
  63. Liu, X.; Huang, J.-Q.; Zhang, Q.; Mai, L. Nanostructured Metal Oxides and Sulfides for Lithium–Sulfur Batteries. Adv. Mater. 2017, 29, 1601759. [Google Scholar] [CrossRef] [PubMed]
  64. Xin, S.; Yu, L.; You, Y.; Cong, H.-P.; Yin, Y.-X.; Du, X.-L.; Guo, Y.-G.; Yu, S.-H.; Cui, Y.; Goodenough, J.B. The Electrochemistry with Lithium versus Sodium of Selenium Confined to Slit Micropores in Carbon. Nano Lett. 2016, 16, 4560–4568. [Google Scholar] [CrossRef] [PubMed]
  65. Antil, B.; Olhan, S.; Vander Wal, R.L. Production of Graphitic Carbon from Renewable Lignocellulosic Biomass Source. Minerals 2025, 15, 262. [Google Scholar] [CrossRef]
  66. Feng, J.; Yu, S.; Shi, C.; Tang, X.; Zhao, X.; Chen, S.; Song, J. Advanced Cathode Designs for High-Energy Lithium/Sodium–Selenium Battery. Adv. Funct. Mater. 2025, 35, 2422013. [Google Scholar] [CrossRef]
Coatings 15 01183 g002
Figure 2. (a) Synthesis illustration of the Se-O-PCS composite. (b) SEM image of the Se-O-PCS. (c) Rate performance of various electrodes. (d) Cycling performance at 0.2 A g−1 of various electrodes. (e) FE-SEM image of Se/MDPC composite. (f) Schematic illustration of the synthesis process for the Se/MDPC composite. (g) TEM image of Se/MDPC composite. (h) Rate performance of Se/MDPC cathodes. (i) Cycling performance at 0.2 C of Se/MDPC cathodes. (a–d) are adapted with permission [26]. Copyright 2021, Elsevier B.V. (e–i) are adapted with permission [35]. Copyright 2019, Elsevier B.V.
Figure 2. (a) Synthesis illustration of the Se-O-PCS composite. (b) SEM image of the Se-O-PCS. (c) Rate performance of various electrodes. (d) Cycling performance at 0.2 A g−1 of various electrodes. (e) FE-SEM image of Se/MDPC composite. (f) Schematic illustration of the synthesis process for the Se/MDPC composite. (g) TEM image of Se/MDPC composite. (h) Rate performance of Se/MDPC cathodes. (i) Cycling performance at 0.2 C of Se/MDPC cathodes. (a–d) are adapted with permission [26]. Copyright 2021, Elsevier B.V. (e–i) are adapted with permission [35]. Copyright 2019, Elsevier B.V.
Coatings 15 01183 g002
Coatings 15 01183 g003
Figure 3. (a) Synthesis illustration of Se-infiltrated N, S-co-doped hierarchically porous carbon. (b) Rate performance of NSHPC-700/Se. (c) SEM image of NSHPC-700. (d) SEM image of NSHPC-700/Se. (e) Cycling performance of NSHPC-700/Se. (f) SEM image of the Se50/SO-HPC3 electrode. (g) Cycling performance of Se50/SO-HPC3 at 0.5 C. (a–e) are adapted with permission [38]. Copyright 2020, American Chemical Society. (f,g) are adapted with permission [40]. Copyright 2019, Royal Society of Chemistry.
Figure 3. (a) Synthesis illustration of Se-infiltrated N, S-co-doped hierarchically porous carbon. (b) Rate performance of NSHPC-700/Se. (c) SEM image of NSHPC-700. (d) SEM image of NSHPC-700/Se. (e) Cycling performance of NSHPC-700/Se. (f) SEM image of the Se50/SO-HPC3 electrode. (g) Cycling performance of Se50/SO-HPC3 at 0.5 C. (a–e) are adapted with permission [38]. Copyright 2020, American Chemical Society. (f,g) are adapted with permission [40]. Copyright 2019, Royal Society of Chemistry.
Coatings 15 01183 g003
Coatings 15 01183 g004
Figure 4. (a) Synthesis illustration of Se@NO-nanocage/CNT cathode. (b) SEM image of Se@NO-nanocage/CNT electrode. (c) Rate performance of Se@NO-nanocage/CNT cathode. (d) Cycling performance and Coulombic efficiency at 1.0 A g−1 over 3500 cycles. (e) Schematic illustration of the synthesis process for CFS@N-C. (f) SEM image of CFS@N-C. (g) Rate performance of CFS@N-C. (a–d) are adapted with permission [28]. Copyright 2020, Wiley-VCH. (e–g) are adapted with permission [41]. Copyright 2021, Springer Nature.
Figure 4. (a) Synthesis illustration of Se@NO-nanocage/CNT cathode. (b) SEM image of Se@NO-nanocage/CNT electrode. (c) Rate performance of Se@NO-nanocage/CNT cathode. (d) Cycling performance and Coulombic efficiency at 1.0 A g−1 over 3500 cycles. (e) Schematic illustration of the synthesis process for CFS@N-C. (f) SEM image of CFS@N-C. (g) Rate performance of CFS@N-C. (a–d) are adapted with permission [28]. Copyright 2020, Wiley-VCH. (e–g) are adapted with permission [41]. Copyright 2021, Springer Nature.
Coatings 15 01183 g004
Coatings 15 01183 g005
Figure 5. (a) Synthesis process of Se@NOPC-CNT electrode. (b) Rate performance at current densities from 0.1 A g−1 to 5 A g−1. (c) Cycling performance of Se@NOPC-CNT cathode at 0.8 A g−1. (d) The galvanostatic discharge/charge of MSTC@Se at different current densities. (e) Cycling performance of MSTC@S and MSTC@Se at 2 A g−1. (a–c) are adapted with permission [23]. Copyright 2018, Wiley-VCH. (d,e) are adapted with permission [45]. Copyright 2025, Royal Society of Chemistry.
Figure 5. (a) Synthesis process of Se@NOPC-CNT electrode. (b) Rate performance at current densities from 0.1 A g−1 to 5 A g−1. (c) Cycling performance of Se@NOPC-CNT cathode at 0.8 A g−1. (d) The galvanostatic discharge/charge of MSTC@Se at different current densities. (e) Cycling performance of MSTC@S and MSTC@Se at 2 A g−1. (a–c) are adapted with permission [23]. Copyright 2018, Wiley-VCH. (d,e) are adapted with permission [45]. Copyright 2025, Royal Society of Chemistry.
Coatings 15 01183 g005
Coatings 15 01183 g006
Figure 6. (a) Synthesis illustration of the 3D-N-CPC/Se cathode. (b) SEM image of 3D-N-CPC/Se composites. (c) TEM image of 3D-N-CPC/Se composites. (d) Synthesis illustration of FNDPC@Se. (e) TEM image of FNDPC. (f) SEM image of PC/Se/GO. (g) Cycling performance of PC/Se/GO at 0.5 C. (a–c) are adapted with permission [48]. Copyright 2024, American Chemical Society. (d,e) are adapted with permission [29]. Copyright 2020, Elsevier Ltd. (f,g) are adapted with permission [49]. Copyright 2020, Wiley-VCH.
Figure 6. (a) Synthesis illustration of the 3D-N-CPC/Se cathode. (b) SEM image of 3D-N-CPC/Se composites. (c) TEM image of 3D-N-CPC/Se composites. (d) Synthesis illustration of FNDPC@Se. (e) TEM image of FNDPC. (f) SEM image of PC/Se/GO. (g) Cycling performance of PC/Se/GO at 0.5 C. (a–c) are adapted with permission [48]. Copyright 2024, American Chemical Society. (d,e) are adapted with permission [29]. Copyright 2020, Elsevier Ltd. (f,g) are adapted with permission [49]. Copyright 2020, Wiley-VCH.
Coatings 15 01183 g006
Coatings 15 01183 g007
Figure 7. (a) Schematic illustration of the synthesis process for the Se@NPCF composite electrode. (b) Long-cycle performance of Se@NPCFs at 0.5 A g−1. (c) A synthesis illustration of the Se@PWC-NS composite. (d) Cycling performance of Se@PWC-NS and pure Se electrodes at 10 C. (e) Synthesis illustration of C-DWHCSs/Se. (f) Cycling performances of various electrodes at 0.1 C. (a,b) are adapted with permission [30]. Copyright 2020, Wiley-VCH. (c,d) are adapted with permission [50]. Copyright 2022, Elsevier Ltd. (e,f) are adapted with permission [31]. Copyright 2022, Elsevier Ltd.
Figure 7. (a) Schematic illustration of the synthesis process for the Se@NPCF composite electrode. (b) Long-cycle performance of Se@NPCFs at 0.5 A g−1. (c) A synthesis illustration of the Se@PWC-NS composite. (d) Cycling performance of Se@PWC-NS and pure Se electrodes at 10 C. (e) Synthesis illustration of C-DWHCSs/Se. (f) Cycling performances of various electrodes at 0.1 C. (a,b) are adapted with permission [30]. Copyright 2020, Wiley-VCH. (c,d) are adapted with permission [50]. Copyright 2022, Elsevier Ltd. (e,f) are adapted with permission [31]. Copyright 2022, Elsevier Ltd.
Coatings 15 01183 g007
Coatings 15 01183 g008
Figure 8. (a) Schematic illustration of synthesis process for Se@P-N-C@Mo2C NF. (b) FE-SEM image of P-N-C@Mo2C. (c) FE-SEM result for Se@P-N-C@Mo2C NF. (d) SEM image of Se-W2N/C. (e) Cycling performance of Se-W2N/C and Se-C at 1.0 A g−1. (a–c) are adapted with permission [32]. Copyright 2025, Elsevier B.V. (d,e) are adapted with permission [53]. Copyright 2023, American Chemical Society.
Figure 8. (a) Schematic illustration of synthesis process for Se@P-N-C@Mo2C NF. (b) FE-SEM image of P-N-C@Mo2C. (c) FE-SEM result for Se@P-N-C@Mo2C NF. (d) SEM image of Se-W2N/C. (e) Cycling performance of Se-W2N/C and Se-C at 1.0 A g−1. (a–c) are adapted with permission [32]. Copyright 2025, Elsevier B.V. (d,e) are adapted with permission [53]. Copyright 2023, American Chemical Society.
Coatings 15 01183 g008
Coatings 15 01183 g009
Figure 9. Prospects of carbon-based materials in cathodes for K-Se batteries.
Figure 9. Prospects of carbon-based materials in cathodes for K-Se batteries.
Coatings 15 01183 g009
Coatings 15 01183 sch001
Scheme 1. The application of carbon-based materials in cathodes for K-Se batteries.
Scheme 1. The application of carbon-based materials in cathodes for K-Se batteries.
Coatings 15 01183 sch001
Table 1. The electrochemical performance of K-Se batteries with various carbon-based positive electrode materials.
Table 1. The electrochemical performance of K-Se batteries with various carbon-based positive electrode materials.
MaterialsSe Content (wt%)/Loading (mg cm–2)Synthesis MethodElectrolyte aVoltage Window (V)Electrochemical Performance (DC b, CD c, CRR d, CN e)Ref.
Encapsulating Se within Carbon Materials
HPC/Se-/1–1.2Melt-diffusion1 M KPF6 in EC/DEC0.5–3.0527, 0.1 C, ~85%, 100[34]
Se-O-PCS51/~1.0Template and melt-diffusion1 M KFSI in EC/DEC0.5–3.0514, 0.2 C, ~80%, 45[26]
Se/MDPC53/1.0–1.8Melt-diffusion1 M KPF6 in EC/PC0.7–2.3~280, 0.2C, ~50%, 100[35]
Se@HCR55/~0.8Solvothermal and melt-diffusion0.8 M KPF6 in EC/DEC0.5–3.0581.4, 0.1 C, 86%, 200[36]
Se@N-HCNS45.6/-Melt-diffusion0.7 M KPF6 in EC/DEC0.5–3.0610, 0.3 C, ~89%, 100[37]
NSHPC-700/Se57–59/1.8–2.1Spray pyrolysis and melt-diffusion1 M KFSI in EC/DEC0.5–3.0461, 0.2 C, ~95%, 120[38]
Se@NPCS60/-Melt-diffusion1 M KPF6 in EC/DEC0.5–2.5604, 0.5 C, ~52%, 300[39]
Se@h-NMCNF60/~1.9Electrospinning and melt-diffusion3 M KFSI in EC/DEC-384, 0.5 C, 54.9%, 1000[24]
Se50/SO-HPC350/~1.5Melt-diffusion1 M KPF6 in EC/DEC0.5–2.5~620, 0.5 C, ~88%, 1700[40]
Se@NO-nanocage/CNT49/-Solution method and melt-diffusion0.7 M KPF6 in EC/DEC0.5–3.0470, 1.5 C, ~82%, 200[28]
CFS@N-C55/0.8–1.0Self-assembly method4 M KFSI in DME-392, 0.15 C, ~97%, 500[41]
Se-HPC42/0.5–1.0Freeze-drying process and melt-diffusion1 M KPF6 in EC/PC0.5–2.5~580, 0.2 C, ~80%, 100[42]
Se@AHCS51.7/~1.0Melt-diffusion0.8 M KPF6 in EC/DEC0.5–2.8547.8, 0.3 C, 59%, 300[43]
Se@NCHS60/~1.2Melt-diffusion3 M KFSI in EC/DEC0.5–3.0~320, 0.5 C, ~62%, 500[44]
Se@NOPC-CNT60/~1.5Melt-diffusion0.7 M KPF6 in EC/DEC0.5–3.0~420, 1.2 C, ~80%, 700[23]
MSTC@Se60/~1.5Melt-diffusion1 M KFSI in EC/DEC0.5–3.0~300, 3 C, ~70%, 2000[45]
Se2–3/Se4–7@MMCFs49.4/1.2–1.5Electrospinning and melt-diffusion0.7 M KPF6 in EC/DEC0.5–3.0443, 1.5 C, 90%, 2000[46]
Se/HHPC47/~1.5Melt-diffusion0.1 M KTFSI in DOL/DME0.5–2.5589, 0.2 C, 39%, 200[47]
3D-N-CPC/Se54/1.0–1.5Freeze-drying and pyrolysis process0.85 M KPF6 in EC/DEC0.5–3.0~590, 2 C, ~39%, 800[48]
PC/Se/GO40/-Melt-diffusion0.8 M KPF6 in EC/DEC0.5–2.5426.3, 0.5 C, 74%, 150[49]
FNDPC@Se40/-Melt-diffusion0.8 M KPF6 in EC/DEC0.5–3.0~150, 3 C, ~72%, 500[29]
Se@NPCFs62/~1.5Electrospinning and melt-diffusion0.7 M KPF6 in EC/DEC0.5–3.0~580, 0.75C, ~63%, 1670[30]
Se@PWC-NS9.75/~3.4Two-step carbonization and melt-diffusion1 M KTFSI in EC/DEC0.001–3.0642.7, 0.2 C, 90%, 200[50]
C-PAN-Se40/0.3–0.5Mixed sintering1 M KPF6 in EC/PC0.7–2.3652, 0.2 C, ~61%, 100[13]
Engineering Chemisorptive Hosts
C-DWHCSs/Se62/1.6–2.0Template and melt-diffusion1 M KPF6 in EC/DEC0.5–3.0612.5, 0.2 C, 91%, 100[31]
Se@MoSe2-HPC35/-Freeze-dried carbonization and melt-diffusion1 M KPF6 in EC/PC0.5–3.0572.4, 1 C, 56%, 500[51]
Electrocatalysis of Redox Reactions
Se@P-N-C@Mo2C58/~1.0Electrospinning and
melt-diffusion		0.7 M KPF6 in EC/DEC0.5–3.0~300, 1 C, ~78%, 220[32]
Se/CoNiSe2-NR76.05/1.0–1.5 (typical); 1.7–3.8 (3D printing)Melt-diffusion and 3D printing1 M KPF6 in EC/DEC0.5–3.0~450, 0.1 C, ~87%, 150[52]
Se-W2N/C45/~1.0Melt-diffusion1 M KTFSI in EC/DEC0.5–3.0540.7, 0.15 C, 74%, 100[53]
1 C = 675 mAh g−1. a EC: ethylene carbonate; DEC: diethyl carbonate; PC: propylene carbonate; DME: 1,2-dimethoxyethane; DOL: 1,3-dioxolane. b DC: discharge capacity (mAh g−1). c CD: current density. d CRR: capacity retention rate. e CN: cycle number.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Wang, J.; Liang, Y.; Gu, D.; Li, C.; Sui, Z.; Tang, X.; Sun, X.; Liu, Y. The Application of Carbon-Based Materials in Cathodes for High-Performance K-Se Batteries: A Review. Coatings 2025, 15, 1183. https://doi.org/10.3390/coatings15101183

AMA Style

Wang J, Liang Y, Gu D, Li C, Sui Z, Tang X, Sun X, Liu Y. The Application of Carbon-Based Materials in Cathodes for High-Performance K-Se Batteries: A Review. Coatings. 2025; 15(10):1183. https://doi.org/10.3390/coatings15101183

Chicago/Turabian Style

Wang, Jingyang, Yanfang Liang, Dongqi Gu, Can Li, Zening Sui, Xibo Tang, Xiaobin Sun, and Yong Liu. 2025. "The Application of Carbon-Based Materials in Cathodes for High-Performance K-Se Batteries: A Review" Coatings 15, no. 10: 1183. https://doi.org/10.3390/coatings15101183

APA Style

Wang, J., Liang, Y., Gu, D., Li, C., Sui, Z., Tang, X., Sun, X., & Liu, Y. (2025). The Application of Carbon-Based Materials in Cathodes for High-Performance K-Se Batteries: A Review. Coatings, 15(10), 1183. https://doi.org/10.3390/coatings15101183

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop