Search Results (171)

Zinc dendrite growth and side reactions remain critical challenges hindering the advancement of aqueous zinc-ion batteries (AZIBs). This study proposes a gel-based strategy for designing high-performance separators by regulating the crystal morphology of the metal–organic framework UiO-66 within a cellulose nanofiber (CNF) gel matrix. The resulting gel-derived separators exhibit distinctive structural and interfacial properties that significantly enhance battery performance. Compared with hierarchical porous structures (H-UiO-66), the octahedral morphology (O-UiO-66) disperses more uniformly in the CNF gel network, forming well-defined ion transport channels through its integrated gel architecture. The fabricated O-UiO-66/CNF gel separator demonstrates exceptional hydrophilicity (contact angle 21°), high porosity (73.2%), and significantly improved zinc ion migration number (0.72). Electrochemical tests reveal that this gel-based separator effectively guides uniform zinc deposition while suppressing dendrite growth. Zn/Zn symmetric cells using the O-UiO-66/CNF gel separator achieve a cycle life exceeding 800 h at 1 mA cm⁻². The Zn/MnO₂ full cell maintains 98.1% capacity retention after 100 cycles at 1 A g⁻¹. This work establishes a structure–performance relationship between MOF morphology and gel separator properties, providing new insights for designing advanced gel-based materials for AZIBs. Full article

Metal–organic frameworks (MOFs) have emerged as versatile precursors and templates for developing high-performance electrode materials for aqueous zinc-ion batteries (ZIBs), owing to their adjustable porosity, abundant metal-coordination sites, and structural flexibility. Among the diverse array of MOFs investigated, those based on manganese, copper, and cobalt, as well as their derivatives, have shown exceptional potential, exhibiting enhanced redox activity, structural integrity, and advantageous zinc-ion storage kinetics compared with many other MOF systems. This study emphasizes the synthesis methodologies, structural characteristics, and electrochemical benefits of these three significant MOF families. After a succinct overview of MOF chemistry, synthesis methodologies, and fundamental design principles for ZIB electrode materials, the article presents a systematic, comparative evaluation of Mn-MOFs, Cu-MOFs, Co-MOFs and V-MOFs, along with their corresponding metal oxides, sulfides, phosphates, carbon composites, and multidimensional hybrid structures. Recent publications for each MOF type are detailed in separate tables, including synthesis methods, morphological development, electrochemical behavior, and performance metrics. The discourse highlights the distinct properties of each metal center, Mn’s multivalent redox chemistry, Cu’s superior electron transport and coordination adaptability, and Co’s elevated activity and stable structures, which together facilitate improved ion diffusion, substantial reversible capacity, and prolonged cycling durability. Ultimately, existing obstacles and potential research avenues are delineated to advance MOF-based materials for next-generation aqueous ZIB systems. Full article

As demand for high-performance energy storage grows across grid and mobility sectors, multivalent ion batteries (MVIBs) have emerged as promising alternatives to lithium-based systems due to their potential for higher volumetric energy density and material abundance. This review comprehensively examines recent breakthroughs in magnesium, zinc, aluminum, and calcium-based battery chemistries, with a focus on overcoming barriers related to slow ion transport, limited reversibility, and electrode degradation. Advances in aqueous and non-aqueous electrolyte formulations, including solvation shell engineering, interfacial passivation, and dual-zone ion transport, are discussed for their role in improving compatibility and cycling stability. Particular focus is placed on three high-impact innovations: solvation-optimized Mg-ion systems for improved mobility and retention, interface-engineered Zn-ion batteries enabling dendrite-free operation, and sustainable Al-ion technologies targeting grid-scale deployment with eco-friendly electrolytes and recyclable materials. Cross-cutting insights from operando characterization techniques and AI-guided materials discovery are also evaluated for their role in accelerating MVIB development. By integrating fundamental materials innovation with practical system design, multivalent ion batteries offer a compelling path toward next-generation, safer, and more sustainable energy storage platforms. Full article

Inherent conductivity and high redox activity endow polyaniline (PANI) with great potential to serve as a cathode material for aqueous zinc-ion batteries. However, compared with traditional strongly acidic electrolytes (pH < 1), its electrochemical performances are moderated in weakly acidic zinc salt electrolytes (pH > 3) because of spontaneous deprotonation. Herein, a carboxyl-modified PANI was designed and synthesized by introducing carboxyl groups at the para-position of the terminal benzene rings within the polymer chains. In this conjugated system, the electron density in the polymer chains was redistributed with a higher one around the substituent due to the electron-withdrawing effect of carboxyl groups and meanwhile carboxyl groups characterized by a proton donor render PANI achieve a proton-involved electrochemical reaction. Consequently, the carboxyl-modified PANI cathode, in a Zn//PANI cell, delivers an impressive specific capacity of 226 mAh g⁻¹ along with excellent rata capability and cycling stability. This work presented some new insights into the molecule structure design of PANI-based polymers applied in advanced aqueous batteries. Full article

The practical application of vanadium-based cathode materials in aqueous zinc-ion batteries (AZIBs) is severely hindered by vanadium dissolution, low electronic conductivity, and sluggish reaction kinetics in aqueous electrolytes. In this work, a three-dimensional confined V₂O₅@ nitrogen-doped carbon (V₂O₅@NC) composite was rationally designed and constructed through a dual-regulation strategy combining oxygen-vacancy engineering and conductive network enhancement. In this architecture, the nitrogen-doped carbon framework provides a highly conductive network and robust structural support, while in situ carbonization induces the generation of oxygen vacancies within V₂O₅. These oxygen vacancies cause lattice distortion and expand the interlayer spacing, thereby accelerating Zn²⁺ diffusion and improving reaction kinetics. Benefiting from this synergistic effect, the V₂O₅@NC electrode exhibits an excellent specific capacity of 437 mAh g⁻¹ at 0.1 A g⁻¹ and maintains a remarkable 89.3% capacity retention after 2000 cycles at 3 A g⁻¹, demonstrating outstanding rate performance and cycling stability. This study provides new insights and an effective design strategy for developing high-performance cathode materials for next-generation aqueous zinc-ion batteries. Full article

This comprehensive review examines the transformative role of metal–organic frameworks (MOFs) in advancing battery separator technology to address critical safety challenges in rechargeable lithium metal batteries. MOF-based separators leverage their highly specific surface area, tunable pore structures, and functionalized organic ligands to enable precise ion-sieving effects, uniform lithium-ion flux regulation, and dendrite suppression—significantly mitigating risks of internal short circuits and thermal runaway. We systematically analyze the mechanisms by which classical MOF families (e.g., ZIF, UiO, MIL series) enhance separator performance through physicochemical properties such as electrolyte wettability, thermal stability (>400 °C), and mechanical robustness. Furthermore, we highlight innovative composite strategies integrating MOFs with polymer matrices (e.g., PVDF, PAN) or traditional separators, which synergistically improve ionic conductivity while inhibiting polysulfide shuttling in lithium–sulfur batteries and side reactions in aqueous zinc-ion systems. Case studies demonstrate that functionalized MOF separators achieve exceptional electrochemical outcomes: Li–S batteries maintain >99% Coulombic efficiency over 500 cycles, while solid-state batteries exhibit 2400 h dendrite-free operation. Despite promising results, scalability challenges related to MOF synthesis costs and long-term stability under operational conditions require further research. This review underscores MOFs’ potential as multifunctional separator materials to enable safer, high-energy-density batteries and provides strategic insights for future material design. Full article

Aqueous zinc-ion batteries (AZIBs) have attracted considerable attention due to their intrinsic safety, low cost, and environmental friendliness. However, drastic volume expansion, sluggish reaction kinetics, and the insufficient structural stability of electrode materials still remain key challenges. In this work, a cascade structure-guided electron transport strategy was used to construct a vanadium nitride@carbon nanosheet/carbon nanofiber (VN@CNS/CNF) composite as a high-performance cathode for AZIBs. In this rationally engineered architecture, carbon-coated VN nanoparticles are uniformly anchored on a conductive carbon nanofiber network, forming a multidimensional interconnected structure that enables fast electron/ion transport and robust mechanical stability. The carbon shell effectively alleviates volume expansion and prevents VN nanoparticle agglomeration, while the continuous carbon fiber backbone reduces charge transfer resistance and enhances reaction kinetics. Benefiting from this synergistic structural design, the VN@CNS/CNF electrode delivers a high specific capacity of 564 mAh g⁻¹ at 0.1 A g⁻¹, maintains 99% capacity retention after 50 cycles, and retains 280 mAh g⁻¹ even at 8 A g⁻¹ after prolonged cycling. This study provides a new structural engineering strategy for vanadium nitride-based electrodes and provides strategic guidance for the development of fast-charging, durable aqueous zinc-ion batteries. Full article

Element doping technology is widely recognized as an effective strategy for high-performance MnO₂-based cathode materials. While this approach improves the electronic and ionic conductivity of MnO₂, it is often accompanied by the introduction of oxygen vacancies. This synergistic effect poses challenges for precisely investigating the effect of doping elements on the d-electron configuration of the Mn site and establishing atomic-level structure-activity relationships for high-energy aqueous zinc-MnO₂ batteries. In this paper, the rational design of d-electron configurations in the Mn site has been achieved through simple Co doping in α-MnO₂ (CMO). Experimental results confirm that the introduction of Co can delocalize the d-electrons of the Mn site and increase the ratio of e_g (d_z² and d_x²_−y²) occupancy. Consequently, the charge transfer resistance, electrode polarization, and Zn²⁺ diffusion coefficient of the CMO-2 cathode have been greatly optimized. Thus, the as-prepared electrode delivers a high specific capacity of 287.4 mAh g⁻¹ at 1 A g⁻¹, with a capacity retention rate of 92.8% and a corresponding remaining capacity of 199.7 mAh g⁻¹ after 700 cycles. This study paves the road for the designation and construction of high-energy MnO₂ cathodes with optimized electronic structures for advanced aqueous zinc ion batteries. Full article

Water-induced corrosion and zinc dendrite formation seriously disrupt the Zn plating/stripping process at the anode/electrolyte interface, which results in the instability of the Zn metal anode in aqueous zinc-ion batteries. To address the issues of the zinc metal anode, three water-soluble polymers with different hydrophilic groups—polyacrylic acid (PAA), polyacrylamide (PAM), and polyethylene glycol (PEG)—were designed as electrolyte additives in ZnSO₄ electrolytes. Among them, the PAA-based system exhibited an optimal electrochemical performance, achieving a stable cycling for more than 360 h at a current density of 5 mA cm⁻² with an areal capacity of 2 mA h cm⁻². This improvement could be attributed to its carboxyl groups, which effectively suppresses zinc dendrite growth, electrode corrosion, and side reactions, thereby enhancing the cycling performance of zinc-ion batteries. This work provides a reference for the optimization of zinc anodes in aqueous zinc-ion batteries. Full article

Owing to the inherent safety, environmental friendliness, and high theoretical capacity (820 mAh g⁻¹) of zinc metal, aqueous zinc-ion batteries (AZIBs) have emerged as up-and-coming alternatives to organic lithium-ion batteries. However, the insufficient electrochemically active sites, poor structural stability, and severe interfacial side reactions of cathode materials have always been key challenges, restricting battery gravimetric energy density and cycling stability. This article systematically reviews current mainstream AZIB cathode material systems, encompassing layered manganese- and vanadium-based metal oxides, Prussian blue analogs, and emerging organic polymers. It focuses on analyzing the energy storage mechanisms of different material systems and their structural evolution during Zn²⁺ (de)intercalation. Furthermore, mechanisms of innovative strategies for improving cathodes are thoroughly examined here, such as nanostructure engineering, lattice doping control, and surface coating modification, to address common issues like structural degradation, manganese/vanadium dissolution, and interface passivation. Finally, this article proposes future research directions: utilizing multi-scale in situ characterization to elucidate actual reaction pathways, constructing artificial interface layers to suppress side reactions, and optimizing full-cell design. This review provides a new perspective for developing practical AZIBs with high specific energy and long lifespans. Full article

Aqueous zinc-ion batteries (ZIBs) have attracted growing interest as promising candidates for large-scale and flexible energy storage due to their intrinsic safety, low cost, and environmental sustainability. However, several persistent issues—such as uncontrolled Zn dendrite growth, hydrogen evolution-induced anode corrosion, and cathode dissolution—continue to hinder their commercial deployment. To address these challenges, hydrogel polymer electrolytes (HPEs) have emerged as an effective strategy. Their unique three-dimensional polymer networks not only retain water and confine ion transport, but also provide a solid–liquid hybrid environment that enhances ionic conductivity and interfacial compatibility. These features enable HPEs to suppress side reactions and improve both electrochemical stability and mechanical adaptability, which are especially valuable for flexible ZIB devices. This review first summarizes fundamental energy storage mechanisms in aqueous ZIBs, including reversible Zn²⁺ insertion/extraction, proton co-insertion, and cathode phase evolution. It then highlights recent progress in HPE design, with emphasis on polyacrylamide (PAM), polyvinyl alcohol (PVA), and polyacrylic acid (PAA)-based systems, with strategies for dendrite suppression, interfacial regulation, and mechanical robustness. Finally, current challenges and future directions are discussed, with a forward-looking perspective on scalable fabrication methods, advanced electrolyte design, and deeper mechanistic understanding necessary to fully realize the potential of HPE-enabled aqueous ZIBs. Full article

Aqueous zinc-ion batteries (ZIBs) have emerged as a promising candidate for large-scale energy storage due to their inherent safety, low cost, and environmental friendliness. However, manganese dioxide (MnO₂)-based cathodes, which are widely studied for ZIBs owing to their high theoretical capacity and low cost, face severe capacity fading issues that hinder the commercialization of ZIBs. This performance degradation mainly stems from the weak van der Waals forces between MnO₂ layers leading to structural collapse during repeated Zn²⁺ insertion and extraction; it is also exacerbated by irreversible Mn dissolution via Mn³⁺ disproportionation that depletes active materials, and further aggravated by dynamic electrolyte pH fluctuations promoting insulating zinc hydroxide sulfate (ZHS) formation to block ion diffusion channels. To address these interconnected challenges, in this study, a synergistic strategy was developed combining crystal engineering and pH buffer regulation. We synthesized three MnO₂ polymorphs (α-, δ-, γ-MnO₂), identified δ-MnO₂ with flower-like microspheres as optimal, and introduced sodium dihydrogen phosphate (NaH₂PO₄) as a pH buffer (stabilizing pH at 2.8 ± 0.2). The modified electrolyte improved δ-MnO₂ wettability (contact angle of 17.8° in NaH₂PO₄-modified electrolyte vs. 26.1° in base electrolyte) and reduced charge transfer resistance (Rct = 78.17 Ω), enabling the optimized cathode to retain 117.25 mAh g⁻¹ (82.16% retention) after 2500 cycles at 1 A g⁻¹. This work provides an effective strategy for stable MnO₂-based ZIBs, promoting their application in renewable energy storage. Full article

Aqueous zinc-ion batteries (AZIBs) have attracted significant attention for large-scale energy storage owing to their high safety, low cost, and environmental friendliness. However, issues such as dendrite growth, hydrogen evolution, and corrosion at the zinc anode severely limit their cycling stability. In this study, a “synergistic solvation shell–interfacial adsorption regulation” strategy is proposed, employing potassium gluconate (KG) and dimethyl sulfoxide (DMSO) as composite additives to achieve highly reversible zinc anodes. DMSO integrates into the Zn²⁺ solvation shell, weakening Zn²⁺-H₂O interactions and suppressing the activity of free water, while gluconate anions preferentially adsorb onto the zinc anode surface, inducing the formation of a robust solid electrolyte interphase (SEI) enriched in Zn(OH)₂ and ZnCO₃. Nuclear magnetic resonance(NMR), Raman, and Fourier transform infrared spectroscopy(FTIR) analyses confirm the reconstruction of the solvation structure and reduction in water activity, and X-ray photoelectron spectroscopy(XPS) verifies the formation of the SEI layer. Benefiting from this strategy, Zn||Zn symmetric cells exhibit stable cycling for over 1800 h at 1 mA cm⁻² and 1 mAh cm⁻², and Zn||Cu cells achieve an average coulombic efficiency of 96.39%, along with pronounced suppression of the hydrogen evolution reaction. This work provides a new paradigm for the design of low-cost and high-performance electrolyte additives. Full article

The cycling stability and widespread practical implementation of aqueous zinc ion batteries (AZIBs) are impeded by dendrite growth and the hydrogen evolution reaction (HER). Herein, theaflavins, a low-cost organic bio-compounds and a major component of tea, were innovatively introduced as an electrolyte additive for AZIBs to address these challenges. When added into the electrolyte, theaflavins, with their strong de-solvation capability, facilitated the more uniform and stable diffusion of zinc ions, effectively suppressing dendrite formation and HER. This, in turn, significantly enhanced the coulombic efficiency (>95% in Zn/Cu system) and the stability of the zinc deposition/stripping process in Zn/Zn system. The Zn/Zn symmetric battery system stably cycled for approximately 3000 h at current densities of 1 mA/cm². Compared with H₂O molecules, theaflavins exhibited a narrower LUMO and HOMO gap and higher adsorption energy on zinc surfaces. These properties enabled theaflavins to be preferentially adsorbed onto zinc anode surfaces, forming a protective layer that minimized direct contact between water molecules and the zinc surface. This layer also promoted the electron transfer associated with zinc ions, thereby greatly enhancing interfacial stability and significantly mitigating HER. When 10 mmol/L of theaflavins was present in the electrolyte, the system exhibited lower impedance activation energy, a smoother zinc ion deposition process, reduced corrosion current, and higher HER overpotential. Furthermore, incorporating theaflavins into the electrolyte enhanced the vanadium redox reaction and accelerated zinc ion diffusion, thereby significantly improving battery performance. This work explores the design of a cost-effective electrolyte additive, providing essential insights for the progress of practical AZIBs. Full article