Search Results (69)

Lithium- and sodium-ion batteries (LIBs and SIBs) suffer from the significant degradation of electrochemical performance at low temperatures. This work presents promising hybrid anodes synthesized by the rapid thermolysis of ammonium tetrathiomolybdate and graphene oxide (GO) at 600 and 700 °C. Transmission electron microscopy revealed the formation of MoS₂ crystallites oriented along or perpendicular to the surface of reduced GO (rGO) layers. X-ray photoelectron spectroscopy found the covalent C–S bonds connecting components in the MoS₂/rGO hybrids. The MoS₂/rGO_600 hybrid showed higher specific capacities in LIBs of 1370 mAh/g, 835 mAh/g, and 711 mAh/g at a current density of 0.1 A/g and temperatures of 25 °C, 0 °C, and −20 °C, respectively, due to the presence of excess sulfur in the sample. Increasing the current density to 2 A/g retained 78 and 34% of the capacity at 25 °C and −20 °C. In SIBs, the MoS₂/rGO_700 hybrid showed more promising results, achieving 550 mAh/g at 0.1 A/g and 400 mAh/g at 2 A/g, while lowering the temperature to −20 °C retained 48 and 17% of the capacity. Such good SIB performance is attributed to the enrichment of the sample with vertically oriented MoS₂ layers covalently bonded to the rGO surface. Full article

With the rapid development of electrical energy storage technologies, traditional battery systems are limited in practical applications by insufficient energy density and short cycle life. This review provides a comprehensive and critical summary of MXene or MXene-based composites as electrode materials for high-performance energy storage devices. By integrating the synthesis techniques of MXenes that have been studied, this paper systematically illustrates the physicochemical properties, synthesis strategies, and mechanisms of MXenes, and analyzes the bottlenecks in their large-scale preparation. Meanwhile, it collates the latest research achievements of MXenes in the field of metal–ion batteries in recent years, focusing on integrating their latest progress in lithium–ion, sodium–ion, lithium–sulfur, and multivalent ion (Zn²⁺, Mg²⁺, Al³⁺) batteries, and reveals their action mechanisms in different electrode material cases. Combining DFT analysis of the effects of surface functional groups on adsorption energy with experimental studies clarifies the structure–activity relationships of MXene-based composites. However, the development of energy storage electrode materials using MXenes and their hybrid compounds remains in its infancy. Future development directions for MXene-based batteries should focus on understanding and regulating surface chemistry, investigating specific energy storage mechanisms in electrodes, and exploring and developing electrode materials related to bimetallic MXenes. Full article

Layered double hydroxides (LDHs), notable for their unique two-dimensional layered structures, have attracted significant research attention due to their exceptional versatility and promising performance in energy storage and conversion applications. This comprehensive review systematically addresses the fundamentals and diverse synthesis strategies for LDHs, including co-precipitation, hydrothermal synthesis, electrochemical deposition, sol-gel processes, ultrasonication, and exfoliation techniques. The synthesis methods profoundly influence the physicochemical properties, morphology, and electrochemical performance of LDHs, necessitating a detailed understanding to optimize their applications. In this paper, the role of LDHs in batteries, supercapacitors, and hydrogen production is critically evaluated. We discuss their incorporation in various battery systems, such as lithium-ion, lithium–sulfur, sodium-ion, chloride-ion, zinc-ion, and zinc–air batteries, highlighting their structural and electrochemical advantages. Additionally, the superior pseudocapacitive behavior and high energy densities offered by LDHs in supercapacitors are elucidated. The effectiveness of LDHs in hydrogen production, particularly through electrocatalytic water splitting, underscores their significance in renewable energy systems. This review paper uniquely integrates these three pivotal energy technologies, outlining current innovations and challenges, thus fulfilling a critical need for the scientific community by providing consolidated insights and guiding future research directions. Full article

The extensive use of sodium-ion batteries has made it important to develop high-performance anode materials. Owing to their good sustainability, low cost, and excellent electrochemical properties, hard carbon materials are expected to be a good choice, especially biomass-derived hard carbon. In this study, we successfully synthesized a coir-based carbon nanosphere as an anode material. The hard carbon has a low degree of structural ordering, small particle size, and multiple pore networks for easy sulfur doping compared to the conventional direct high-temperature sulfur doping. The material has a high reversible capacity of 536 mAh g⁻¹ and an initial Coulombic efficiency of 53%, maintaining a reversible capacity of 308 mAh g⁻¹ at a high current density of 5 A g⁻¹, achieving a capacity retention of 90.3% after 1000 cycles. The performance enhancement stems from a combination of enlarged layer spacing, an increased specific surface area, enhanced porosity, and doped sulfur atoms. This study provides an effective strategy for the conversion of biomass waste into high-performance sodium-ion anode material batteries. Full article

The imperative for sustainable energy has driven the demand for efficient energy storage systems that can harness renewable resources and store surplus energy for off-peak usage. Among the numerous advancements in energy storage technology, polymeric nanofibers have emerged as promising nanomaterials, offering high specific surface areas that facilitate increased charge storage and enhanced energy density, thereby improving electrochemical performance. This review delves into the pivotal role of nanofibers in determining the optimal functionality of energy storage systems. Electrospinning emerged as a facile and cost-effective method for generating nanofibers with customizable nanostructures, making it attractive for energy storage applications. Our comprehensive review article examines the latest developments in electrospun nanofibers for electrochemical storage devices, highlighting their use as separators and electrode materials. We provide an in-depth analysis of their application in various battery technologies, including supercapacitors, lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, lithium–sulfur batteries, and lithium–oxygen batteries, with a focus on their electrochemical performance. Furthermore, we summarize the diverse fabrication techniques, optimization of key influencing factors, and environmental implications of nanofiber production and their properties. This review aims to offer an inclusive understanding of electrospinning’s role in advancing electrochemical energy storage, providing insights into the factors that drive the performance of these critical materials. Full article

MoS₂, a key material for supercapacitors, batteries, photovoltaics, catalysis, and sensing applications, was synthesized using the hydrothermal method. Different precursors such as molybdenum sources (ammonium heptamolybdate tetrahydrate ((NH₄)₆Mo₇O₂₄·4H₂O) and sodium molybdate hydrate (Na₂MoO₄·2H₂O)) combined with L-cysteine, thiourea, and thioacetamide, as the sulfur source, were involved. The obtained samples were morphologically and structurally characterized by X-ray diffraction, Raman spectroscopy, N₂ adsorption/desorption measurements, and Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM–EDX). Electrochemical impedance spectroscopy was involved in MoS₂ characterization as electrode materials. The objective of this study was to ascertain the impact of precursor combinations on the morphological, structural, and electrochemical characteristics of MoS₂. A thorough examination of the empirical data revealed that the MoS₂ compounds, which were synthesized using thiourea as the sulfur source, exhibited a more pronounced flower-like morphology, increased crystallite size, and enhanced electrochemical properties with potential electrochemical applications. Full article

Polyphenylene sulfide (PPS)-based separators have garnered significant attention as high-performance components for next-generation lithium-ion batteries (LIBs), driven by their exceptional thermal stability (>260 °C), chemical inertness, and mechanical durability. This review comprehensively examines advances in PPS separator design, focusing on two structurally distinct categories: porous separators engineered via wet-chemical methods (e.g., melt-blown spinning, electrospinning, thermally induced phase separation) and nonporous solid-state separators fabricated through solvent-free dry-film processes. Porous variants, typified by submicron pore architectures (<1 μm), enable electrolyte-mediated ion transport with ionic conductivities up to >1 mS·cm⁻¹ at >55% porosity, while their nonporous counterparts leverage crystalline sulfur-atom alignment and trace electrolyte infiltration to establish solid–liquid biphasic conduction pathways, achieving ion transference numbers >0.8 and homogenized lithium flux. Dry-processed solid-state PPS separators demonstrate unparalleled thermal dimensional stability (<2% shrinkage at 280 °C) and mitigate dendrite propagation through uniform electric field distribution, as evidenced by COMSOL simulations showing stable Li deposition under Cu particle contamination. Despite these advancements, challenges persist in reconciling thickness constraints (<25 μm) with mechanical robustness, scaling solvent-free manufacturing, and reducing costs. Innovations in ultra-thin formats (<20 μm) with self-healing polymer networks, coupled with compatibility extensions to sodium/zinc-ion systems, are identified as critical pathways for advancing PPS separators. By addressing these challenges, PPS-based architectures hold transformative potential for enabling high-energy-density (>500 Wh·kg⁻¹), intrinsically safe energy storage systems, particularly in applications demanding extreme operational reliability such as electric vehicles and grid-scale storage. Full article

A comprehensive roadmap for advancing Electric Micromobility (EMM) systems addressing the fragmented and scarce information available in the field is defined as a transformative solution for urban transportation, targeting short-distance trips with compact, lightweight vehicles under 350 kg and maximum speeds of 45 km/h, such as bicycles, e-scooters, and skateboards, which offer flexible, eco-friendly alternatives to traditional transportation, easing congestion and promoting sustainable urban mobility ecosystems. This review aims to guide researchers by consolidating key technical insights and offering a foundation for future exploration in this domain. It examines critical components of EMM systems, including electric motors, batteries, power converters, and control strategies. Likewise, a comparative analysis of electric motors, such as PMSM, BLDC, SRM, and IM, highlights their unique advantages for micromobility applications. Battery technologies, including Lithium Iron Phosphate, Nickel Manganese Cobalt, Nickel-Cadmium, Sodium-Sulfur, Lithium-Ion and Sodium-Ion, are evaluated with a focus on energy density, efficiency, and environmental impact. The study delves deeply into power converters, emphasizing their critical role in optimizing energy flow and improving system performance. Furthermore, control techniques like PID, fuzzy logic, sliding mode, and model predictive control (MPC) are analyzed to enhance safety, efficiency, and adaptability in diverse EMM scenarios by using cutting-edge semiconductor devices like Silicon Carbide (SiC) and Gallium Nitride (GaN) in well-known configurations, such as buck, boost, buck–boost, and bidirectional converters to ensure great efficiency, reduce energy losses, and ensure compact and reliable designs. Ultimately, this review not only addresses existing gaps in the literature but also provides a guide for researchers, outlining future research directions to foster innovation and contribute to the development of sustainable, efficient, and environmentally friendly urban transportation systems. Full article

Recycling of spent lithium-ion batteries is important due to the increasing demand for electric vehicles and efforts to realize a circular economy. There is a need to develop environmentally friendly processes for the refining of nickel, cobalt, and other metals contained in the batteries. Electrodialysis is an appealing method for recycling of battery metals with selective separation and low chemical input. In this study, sodium sulfate was used in an electrodialysis metathesis procedure to sequentially separate EDTA-chelated nickel and cobalt. Replacing hitherto used sulfuric acid with sodium sulfate mitigates membrane fouling caused by precipitation of EDTA. It was possible to separate up to 97.9% of nickel and 96.6% of cobalt at 0.10 M, a 30-times higher concentration than previously reported for electrodialysis of similar solutions. Through the thermally activated persulfate method, new to this application, 99.7% of nickel and 87.0% of cobalt could be precipitated from their EDTA chelates. Impurity behavior during electrodialysis of battery leachates has not previously been described in the literature. It is paramount to remove copper, iron, and phosphorous prior to electrodialysis since they contaminate the nickel product. Aluminum was difficult to remove in the solution purification step and ended up in all electrodialysis products. Full article

Room-temperature all-solid-state sodium–sulfur (Na-S) batteries are being regarded as a promising technology for large-scale energy storage. However, the low ionic conductivity of existing sulfide solid electrolytes has been hindering the potential and commercialization of Na-S batteries. Na₃PS₄ has garnered extensive attention among sulfide solid electrolytes due to its potential ionic conductivity (primarily predominated by vacancies) and ease of fabrication. Herein, we demonstrated a combined melt-quenching with Br doping technique to pre-generate abundant defects (vacancies) in the Na₃PS₄, which expanded ion transport channels and facilitated Na⁺ migration. The quenched Na_2.9PS_3.9Br_0.1 holds an ionic conductivity of 8.28 × 10⁻⁴ S/cm at room temperature. Followed by the hot-pressed fabrication at 450 °C was conducted on the quenched Na_2.9PS_3.9Br_0.1 to reduce interface resistance, the resultant Na_2.9PS_3.9Br_0.1 pellet shows an ionic conductivity up to 1.15 × 10⁻³ S/cm with a wide electrochemical window and chemical stability towards Na alloy anodes. The assembled all-solid-state Na₂S/Na_2.9PS_3.9Br_0.1/Na₁₅Sn₄ cell delivers an initial reversible capacity of 550 mAh/g at a current density of 0.1 mA/cm². After 50 cycles, it still maintains 420 mAh/g with a capacity retention of 76.4%. The integration of melt-quenching, doping, and hot-pressing provides a new strategy to enable sulfide electrolytes with high ionic conductivity and all-solid-state Na-S batteries with high performance. Full article

Sodium–sulfur batteries have been provided as a highly attractive solution for large-scale energy storage, benefiting from their substantial storage capacity, the abundance of raw materials, and cost-effectiveness. Nevertheless, conventional sodium–sulfur batteries have been the subject of critique due to their high operating temperature and costly maintenance. In contrast, room-temperature sodium–sulfur batteries exhibit significant advantages in these regards. The most commonly utilized cathode active material is the S₈ molecule, whose intricate transformation process plays a crucial role in enhancing battery capacity. However, this process concomitantly generates a substantial quantity of polysulfide intermediates, leading to diminished kinetics and reduced cathode utilization efficiency. The pivotal strategy is the design of catalysts with adsorption and catalytic functionalities, which can be applied to the cathode. Herein, we present a summary of the current research progress in terms of nanostructure engineering, catalyst strategies, and regulating sulfur species conversion pathways from the perspective of high-performance host design strategy. A comprehensive analysis of the catalytic performance is provided from four perspectives: metal catalysts, compound catalysts, atomically dispersed catalysts, and heterojunctions. Finally, we analyze the bottlenecks and challenges, offering some thoughts and suggestions for overcoming these issues. Full article

The ever-increasing global energy demand necessitates the development of efficient, sustainable, and high-performance energy storage systems. Nanotechnology, through the manipulation of materials at the nanoscale, offers significant potential for enhancing the performance of energy storage devices due to unique properties such as increased surface area and improved conductivity. This review paper investigates the crucial role of nanotechnology in advancing energy storage technologies, with a specific focus on capacitors and batteries, including lithium-ion, sodium–sulfur, and redox flow. We explore the diverse applications of nanomaterials in batteries, encompassing electrode materials (e.g., carbon nanotubes, metal oxides), electrolytes, and separators. To address challenges like interfacial side reactions, advanced nanostructured materials are being developed. We also delve into various manufacturing methods for nanomaterials, including top–down (e.g., ball milling), bottom–up (e.g., chemical vapor deposition), and hybrid approaches, highlighting their scalability considerations. While challenges such as cost-effectiveness and environmental concerns persist, the outlook for nanotechnology in energy storage remains promising, with emerging trends including solid-state batteries and the integration of nanomaterials with artificial intelligence for optimized energy storage. Full article

Fly ash consists of significant amounts of lithium, which is an essential resource for developing batteries. This study proposed an efficient method for extracting lithium from fly ash. First, we explored the parameters affecting the activation effect of sodium carbonate roasting and the leaching efficiency of lithium using acid leaching. Additionally, ultrasonic pre-treatment was applied to enhance activation. A further mechanism for the roasting extraction of lithium was symmetrically analyzed. The results showed that ultrasonic treatment at 200 W for 1 h under alkaline leaching conditions (sodium hydroxide solution 4 mol/L, reaction temperature 80 °C, leaching time 2 h, solid–liquid ratio 1 g:30 mL) achieved a lithium leaching rate of 90.74%, surpassing the 84.72% with traditional roasting–alkaline leaching. Under optimal acid leaching conditions (850 °C for reaction of 2.5 h, fly ash-to-sodium carbonate ratio (R_fs) 1:2, sulfuric acid 2 mol/L, reaction temperature 80 °C, solid–liquid ratio 1 g:30 mL, and leaching time 1.5 h), the leaching rate reached 96.62%. With ultrasonic pre-treatment and acid leaching, the highest leaching rate of 98.68% achieved under optimal conditions: reaction temperature 850 °C for 2.5 h, mass R_fs at 1:1.5, sulfuric acid 2 mol/L, reaction temperature 80 °C, solid–liquid ratio 1 g:35 mL, and leaching time 120 min. The study demonstrated that ultrasonic pre-treatment outperforms the traditional method, achieving a higher leaching rate with fewer roasting additives and lower energy consumption. Full article

The development of metal sulfides as anodes for sodium-ion batteries (SIBs) is significantly obstructed by the slow kinetics of the electrochemical reactions and the substantial volume changes on the cycling. Herein, we introduce a selenium-substituted cobalt disulfide embedded within a dual carbon–graphene framework (Se-CoS₂/C@rGO) for high-performance SIBs. The Se-CoS₂/C@rGO was prepared via a synchronous sulfurization/selenization strategy using Co-alkoxide as the precursor and SeS₂ as the source of selenium and sulfur, during which the EG anions are converted in situ to a S, Se codoped carbon scaffold. The dual carbon–graphene matrix not only improves the electronic conductivity but also stabilizes the electrode material effectively. In addition, the Se substitution within the CoS₂ lattice further improves the electrical conductivity and promotes the Na⁺ reaction kinetics. The enhanced intrinsic electronic/ionic conductivity and reinforced structural stability endow the Se-CoS₂/C@rGO anode with a high reversible capacity (558.2 mAh g⁻¹ at 0.2 A g⁻¹), superior rate performance (351 mAh g⁻¹ at 20 A g⁻¹), and long cycle life (93.5% capacity retention after 2100 cycles at 1 A g⁻¹). This work provides new insights into the development of stable and reversible anode materials through Se substitution and dual carbon encapsulation. Full article

Room-temperature sodium–sulfur (RT Na–S) batteries offer a superior, high-energy-density solution for rechargeable batteries using earth-abundant materials. However, conventional RT Na–S batteries typically use sulfur as the cathode, which suffers from severe volume expansion and requires pairing with a sodium metal anode, raising significant safety concerns. Utilizing Na₂S as the cathode material addresses these issues, yet challenges such as Na₂S’s low conductivity as well as the shuttle effect of polysulfide still hinder RT Na–S battery development. Herein, we present a simple and cost-effective method to fabricate a Na₂S–Na₆CoS₄/Co@C cathode, wherein Na₂S nanoparticles are embedded in a conductive carbon matrix and coupled with dual catalysts, Na₆CoS₄ and Co, generated via the in situ carbothermal reduction of Na₂SO₄ and CoSO₄. This approach creates a three-dimensional porous composite cathode structure that facilitates electrolyte infiltration and forms a continuous conductive network for efficient electron transport. The in situ formed Na₆CoS₄/Co electrocatalysts, tightly integrated with Na₂S, exhibit strong catalytic activity and robust physicochemical stabilization, thereby accelerating redox kinetics and mitigating the polysulfide shuttle effect. As a result, the Na₂S–Na₆CoS₄/Co@C cathode achieves superior capacity retention, demonstrating a discharge capacity of 346 mAh g⁻¹ after 100 cycles. This work highlights an effective strategy for enhancing Na₂S cathodes with embedded catalysts, leading to enhanced reaction kinetics and superior cycling stability. Full article