Search Results (395)

The performance, safety, and long-term durability of electric vehicle (EV) battery systems are strongly governed by the chemical stability and thermophysical properties of their constituent materials. In response to the limitations of conventional lithium-based batteries—particularly with respect to thermal stability, material sustainability, and degradation under high operational loads—this study presents a thermodynamic and electrochemical modeling framework for evaluating alternative battery materials relevant to electric vehicle energy storage systems. Xenon difluoride (XeF₂) and zirconium carbide (ZrC) are proposed as functional battery components and comparatively analyzed based on chemical stability, bond enthalpy, mass–capacity relationships, and energy density characteristics. Analytical modeling is employed to investigate voltage–capacity–mass interactions over a wide operating range (3–48 V and 100–1000 mAh), representing diverse EV operating scenarios, including high-load and elevated-temperature conditions. In addition, temperature-dependent degradation behavior and cycle life performance are assessed using logarithmic degradation models and Arrhenius-based life cycle formulations. The results indicate that ZrC, with a high total bond enthalpy of 561 kJ mol⁻¹, demonstrates superior energy density, reduced material mass requirements, and enhanced resistance to thermal degradation, making it particularly suitable for high-temperature and long-life EV battery applications. In contrast, XeF₂ exhibits stable electrochemical performance under moderate temperature and capacity conditions but shows increased sensitivity to thermal effects at higher operating ranges, suggesting potential applicability in balanced-performance EV battery configurations. Overall, the proposed modeling framework provides a systematic approach for assessing alternative battery materials under electric vehicle-relevant operating conditions and offers guidance for future experimental validation, material selection, and battery design aimed at improving safety, durability, and sustainability in next-generation electric vehicle energy storage systems. Full article

In the context of the rapid growth of the electric and hybrid vehicle fleet, ensuring the reliability, safety, and durability of traction lithium-ion battery packs has become a key scientific and engineering challenge. The technical condition of battery packs, characterized by such parameters as state of charge (SOC), state of health (SOH), and remaining useful life (RUL), directly affects vehicle performance and the total cost of ownership of electric vehicles. This review article systematizes and analyzes current approaches to assessing the technical condition of battery packs. Fundamental degradation mechanisms and factors are considered, including operational, thermal, and mechanical effects. A detailed analysis is presented for the three main classes of diagnostic methods: model-based approaches, data-driven approaches (machine learning and deep learning), and hybrid methods combining the advantages of the former two. Particular attention is paid to methods for early fault detection, thermal runaway prediction, and condition assessment based on real-world operational data. The article presents quantitative results demonstrating the accuracy and effectiveness of various algorithms and also discusses key challenges and promising research directions, such as the use of cloud platforms, digital twins, and explainable artificial intelligence methods. Full article

Layered sodium transition-metal oxides are promising cathode materials for sodium-ion batteries due to their high theoretical capacity; however, their practical application is often limited by sluggish Na⁺ diffusion kinetics and structural instability during cycling. P2/O3 phase coexistence has been proposed as an effective strategy to balance capacity and stability, yet it is typically achieved through precise Na-content tuning or complex synthesis conditions, which restrict compositional flexibility. Herein, we demonstrate a phase-engineering approach that induces stable P2/O3 phase coexistence without adjusting the overall Na stoichiometry by controlling the dopant incorporation pathway. Using Na_0.8(Ni_0.25Fe_0.33Mn_0.33Cu_0.07)O₂ (NaNFMC) as a model system, Mg doping via a wet chemical route enables homogeneous dopant distribution, which triggers local stacking rearrangement and the formation of prismatic Na⁺ diffusion channels characteristic of the P2 phase. In contrast, dry-doped samples with identical Mg content retain a predominantly O3-type structure, highlighting the decisive role of dopant incorporation in governing phase evolution. As a result of the phase-engineered P2/O3 coexisting framework, the Mg wet-doped cathode exhibits enhanced initial reversibility, superior rate capability, and improved long-term cycling stability compared to pristine and dry-doped counterparts. Voltage-resolved dQ/dV and cyclic voltammetry analyses reveal stabilized redox behavior with reduced polarization, while electrochemical impedance spectroscopy confirms suppressed impedance growth and improved Na⁺ transport kinetics after cycling. This study establishes that phase engineering through controlled dopant incorporation provides an effective alternative to conventional Na-content tuning strategies for layered sodium cathodes. The findings offer a scalable and versatile design principle for optimizing the electrochemical performance and structural durability of next-generation sodium-ion battery cathode materials. Full article

Carbon-based bifunctional oxygen electrocatalysts with rationally designed architectures are essential for high-performance rechargeable zinc–air batteries (ZABs), yet the concurrent optimization of catalytic activity, durability, and mass transport remains challenging. Herein, hierarchical ZnCo carbon nanofibers/carbon nanotubes (CNFs@CNTs) are fabricated via single-nozzle electrospinning followed by melamine-assisted pyrolysis under a ZnCl₂-regulated atmosphere. During thermal treatment, Co species embedded within carbon nanofibers catalyze in situ carbon nanotube growth, while ZnCl₂ vapor modulates the carbonization process and surface chemistry, collectively generating a hierarchical CNFs@CNTs architecture with high surface area and abundant exposed active sites. As a result, ZnCo CNFs@CNTs exhibit outstanding bifunctional ORR/OER activity, surpassing Zn-free and Co-free counterparts. Combined structural and electrochemical analyses reveal that the synergistic interaction between Co active centers and Zn-assisted carbon structural regulation enhances reaction kinetics and long-term stability. When implemented as air electrodes in rechargeable ZABs, ZnCo CNFs@CNTs deliver high power density, reduced charge–discharge polarization, and excellent cycling durability, demonstrating strong practical applicability. This work presents an effective strategy for constructing hierarchical CNFs@CNTs composites via electrospinning and dual-component thermal regulation, offering new insights into the design of high-efficiency bifunctional air electrodes for advanced ZABs. Full article

Although halide solid electrolytes (HSEs) demonstrate a higher voltage window and superior interfacial stability toward Li-rich layered oxides (LLOs) compared to sulfide systems, HSE-based all-solid-state lithium batteries (HSE-ASSLBs) still face a fundamental trade-off between achieving high capacity and maintaining cycling stability. To resolve this issue, a rational adjustment of the depth-of-discharge (DOD) via discharge cut-off voltage control is proposed. Analysis of dQ/dV profiles and post-cycled electrodes indicates that excessive DOD (lower cut-off voltages) aggravates structural degradation and interfacial side reactions, whereas insufficient DOD (higher cut-off voltage) fails to fully utilize the compensatory capacity from low-voltage redox couples. Notably, an optimized cut-off voltage of 2.6 V activates a stable low-voltage redox reaction centered around 2.85 V, which effectively offsets high-voltage capacity loss while suppressing unfavorable interfacial evolution. As a result, the ASSLB configured with a Li_1.2Ni_0.13Mn_0.54Co_0.13O₂ cathode and a Li_2.75In_0.75Zr_0.25Cl₆ HSE delivers an initial discharge capacity of 281.6 mAh g⁻¹ at 1C and achieves significantly improved capacity retention from 71.8% to 86.1% over 300 cycles. This study confirms that DOD regulation offers a simple and effective electrochemical protocol for enabling durable high-capacity output in LLO-based ASSLBs. Full article

The development of lithium-ion batteries (LIBs) capable of extreme fast charging (XFC) while preserving safety, durability, and practical energy density remains a central challenge for next-generation electric transportation and grid-scale storage. Conventional graphite anodes are fundamentally limited at high current densities by sluggish intercalation kinetics, which cause lithium plating, motivating the exploration of alternative insertion materials. This review provides a comprehensive and internally consistent assessment of titanium-based oxide anodes, encompassing TiO₂ polymorphs, lithium titanate (Li₄Ti₅O₁₂), and Wadsley–Roth titanium niobium oxides, through the combined lenses of crystal topology, diffusion pathways, redox chemistry, interfacial behavior, and resource scalability. By systematically comparing structural frameworks and electrochemical mechanisms across these material classes, we demonstrate that fast-charging performance is governed not by nano-structuring alone, but by the intrinsic coupling between operating potential, framework rigidity, and multi-electron redox activity. While Li₄Ti₅O₁₂ establishes the benchmark for safety and cyclability, and TiO₂ polymorphs provide structural versatility, titanium niobium oxides uniquely reconcile high theoretical capacity with minimal lithiation strain and open diffusion channels, positioning them as highly promising candidates for sub-10 min charging without catastrophic degradation. This review highlights the persistent obstacles these materials suffer, such as limited round-trip energy efficiency (RTE), interfacial gas evolution, poor dopant stability, and unsustainable extraction, while simultaneously exploring targeted design strategies to overcome them. Finally, this review provides a materials design and comparison framework for the development of safe, high-power, and commercially viable ultrafast-charging LIBs. Full article

Owing to its high theoretical sodium-storage capacity of approximately 1000 mAh g⁻¹ and cost-efficient characteristics, Fe₂VO₄ has emerged as a highly attractive anode material for sodium-ion batteries (SIBs). In this work, MXene-incorporated Fe₂VO₄ composites were successfully synthesized. Comprehensive electrochemical characterization demonstrates that MXene incorporation significantly enhances the electronic conductivity and sodium-ion diffusion kinetics of Fe₂VO₄, while effectively mitigating volume expansion during cycling. The synthetic substantially improves its cycling stability and rate capability. When the MXene loading ratio is optimized at 5 wt%, the composite exhibits outstanding cyclic durability, with a remarkable reversible specific capacity of 323.3 mAh g⁻¹ maintained after 200 cycles at a current density of 0.1 A g⁻¹. Furthermore, the composite demonstrates outstanding rate performance, with a specific capacity of 164.5 mAh g⁻¹ achieved at a current density of 2 A g⁻¹. The synergistic integration of Fe₂VO₄ and MXene not only constructs a three-dimensional electrically conductive framework for efficient charge transport but also reinforces strong structural stability against cycling-induced degradation. This work proposes a versatile engineering strategy that can be adapted for other conversion-type electrode materials in the context of advanced energy storage technologies. Full article

This review aims to assess the clinical performance and application results of oral wearable devices in in vivo trials. Following a systematic search of PubMed, Cochrane, Embase, and Scopus databases up to 15 October 2025, and strict screening in accordance with PRISMA 2020 guidelines, 13 in vivo human trials were finally included for analysis. These were analyzed across four clinical functions: diagnosis, treatment, monitoring, and prevention. These devices have evolved from bulky prototypes into miniaturized, wireless systems with diverse diagnostic and therapeutic functions. Their applications now extend beyond common conditions like caries and bruxism to postoperative recovery and pediatric dental anxiety intervention. The findings show that some devices already offer practical value for clinical screening and auxiliary diagnosis. They demonstrate significant potential in early disease detection and medical cost control. However, development still faces many challenges. Technical issues include limited battery life, insufficient mechanical durability, and wireless transmission constraints within the oral environment. Furthermore, clinical evidence levels remain low, indications are narrow, and dedicated ethical and regulatory frameworks are lacking. Inconsistent regulatory standards, production costs, and clinician adoption hurdles slow its commercial development. In the future, the integration of AI, breakthroughs in energy harvesting, and the creation of digital health platforms will be key to overcoming technical bottlenecks. Full article

Calcium-ion batteries (CIBs) offer several advantages. CIBs are viable alternatives to lithium-based battery systems owing to the natural abundance, low cost, and high volumetric capacity of calcium. However, their development has been severely constrained by electrolyte instability and water sensitivity. We conducted a systematic examination of Ca(ClO₄)₂ and Ca(PF₆)₂ electrolytes, focusing on low-cost salt production, solvent selection, and stringent dehydration procedures. Acetonitrile (ACN) was the ideal solvent for high salt solubility and reversible Ca²⁺ electrochemistry, while carbonate solvents failed rapidly. We found that even a small amount of moisture in the electrolyte significantly affected the electrochemical performance. This study improved the dehydration process by using 3 Å molecular sieve (MS3A) and vacuum drying to reduce moisture to ppm levels, stabilizing the electrolyte. Prussian blue (PB) half cells exhibited reversible capacities of up to ≈95 mAh g⁻¹, whereas PB-hard carbon full cells utilizing dried Ca(ClO₄)₂ showed stable cycling over 240 cycles with a Coulombic efficiency of ≈99% and capacity loss of only ≈17%. This study establishes a moisture-controlled electrolyte as a critical enabler for practical CIBs. Full article

Addressing the thermal management challenges of prismatic aluminum shell lithium battery modules in electric vehicles under high-rate charge–discharge conditions, this study proposes a multi-objective optimization design method for integrated biomimetic liquid cooling plates. By integrating various highly efficient heat transfer structures from nature, including fractal-tree-like networks, leaf vein branching systems, and spider web radial distribution, a novel biomimetic liquid cooling plate topology was constructed. A multi-physics coupled numerical model considering electrochemical heat generation, thermal conduction, convective heat transfer, and thermal stress deformation was established. The NSGA-II algorithm was employed to globally optimize 12 design variables including channel geometric parameters, operating conditions, and structural dimensions, achieving collaborative optimization objectives of maximum temperature minimization, temperature uniformity maximization, pressure drop minimization, and structural lightweighting. The weight coefficients for the four optimization objectives were determined through the Analytic Hierarchy Process (AHP) with verified consistency (CR = 0.02 < 0.10), ensuring rational priority allocation aligned with automotive safety standards. The optimization results demonstrated that compared to the initial design, the optimal solution reduced the maximum temperature under 3C discharge conditions by 9.9% to 34.7 °C, decreased the temperature difference by 31.3% to 3.3 °C, lowered the pressure drop by 24.6% to 2150 Pa, reduced structural mass by 4.0%, and decreased maximum stress by 16.7%. Quantitative comparison with single biomimetic structures under identical boundary conditions showed that the integrated design achieved a 3.3% lower maximum temperature and 25.7% better flow uniformity than the best-performing single structure, demonstrating the synergistic advantages of multi-biomimetic integration. These synergistic performance improvements can be attributed to the hierarchical multi-scale architecture where fractal networks provide macro-scale flow distribution, leaf vein branches ensure meso-scale coverage, and spider web radials achieve micro-scale thermal matching. Long-term cycling tests conducted at 1C/1C rate with 25 ± 1 °C ambient temperature showed that the optimized design maintained a capacity retention rate of 92.3% after 1000 charge–discharge cycles, demonstrating excellent durability. The complex biomimetic channel structure can be fabricated using selective laser melting technology with minimum feature sizes below 0.3 mm, indicating promising manufacturing feasibility. The research findings provide theoretical guidance and technical support for the engineering design of high-performance battery thermal management systems. Full article

Conductive thread is an integral aspect of smart textiles in the domain of electronic textiles (e-textiles). This study unveils the development of twelve distinct variants of conductive threads using the twisting method: the fusion of copper filament with cotton and polyester threads. The threads are coated with a carbon paste solution enriched with dissolved sea salt. The carbon paste is obtained from non-functional dry cell batteries, conventionally categorized as hazardous electronic waste (e-waste), which underscores an economically viable and environmentally sustainable approach. Experiments proved that each variant demonstrates minimal electrical resistance. The lowest resistance, 0.0164 ± 0.0001 Ω/cm, was achieved by Carbon-Coated Cotton Twisted Copper Thread-II. Comparative evaluation with commercially available conductive threads, including Bekaert Bekinox^® VN type (12/1x275/100z), indicated comparable or moderately lower resistance values for the developed copper-based threads. Mechanical–electrical stability under bending, twisting, and wash–dry cycles confirmed consistent conductive performance with minimal resistance variation. Practical demonstrations further validated the integration of the threads into fabric-based flexible circuits and wearable electronic systems. These findings demonstrate that twisted copper-based conductive threads derived from sustainable coating materials provide a promising alternative for smart textile and wearable electronic applications. Future research should focus on scalable fabrication, enhanced coating fixation, and long-term durability assessment. Full article

This review synthesizes recent progress in modern energy storage technologies and proposes a selection-oriented comparison for power-system stabilization. Technologies are grouped into electrochemical, mechanical, chemical, and thermal storage, and evaluated using harmonized criteria (power and energy capability, response time, round-trip efficiency, lifetime, cost proxies, and maturity level). A comparative dataset and use-case mapping are used to link technology characteristics to grid services, with emphasis on voltage support, operational durability, and waste-heat utilization. The analysis highlights pumped-storage hydropower as the most robust option for long-duration, high-capacity applications, while battery energy storage systems are best suited for fast ancillary services, provided that cycle life, safety, and system integration constraints are met. Finally, the review discusses current technology trends (e.g., LFP and sodium-ion deployment, solid-state development, and commercialization barriers for lithium-sulfur) and identifies evidence-based directions for future research and deployment. Full article

Renewable Energy Communities (RECs) are recognized as effective collective models to accelerate decarbonization through shared renewable generation, consumption, and local flexibility provision. However, their large-scale deployment remains constrained by the temporal mismatch between variable renewable generation and strongly time-dependent demand, particularly in buildings where heating and cooling dominate final energy use. This state-of-the-art review provides an integrated and comparative assessment of Thermal Energy Storage (TES) and Battery Energy Storage Systems (BESS) within RECs, with explicit focus on power-to-heat (PtH) pathways and phase change material (PCM)-based cooling storage. Based on a structured analysis of the peer-reviewed literature published between 2015 and 2025, the review shows that TES represents a cost-effective and durable complement to electrochemical storage in heating- and cooling-dominated communities. Reported results indicate that TES integration can reduce peak electrical demand by 20–35%, increase local renewable self-consumption by 15–40%, and significantly lower required battery capacity in hybrid configurations. While BESS remains indispensable for short-term electrical balancing and fast-response grid services, TES offers lower costs per kWh stored, longer operational lifetimes (often exceeding 25–40 years), and lower lifecycle greenhouse gas emissions, typically 70–85% lower than those of BESS when thermal energy is used directly. Among TES technologies, PCM-based systems demonstrate particular effectiveness in cooling-dominated RECs, enabling peak cooling power reductions of up to 30% through diurnal load shifting. Across climatic contexts, the literature converges on hybrid TES–BESS architectures as the most robust storage solution, with reported reductions in grid imports and renewable curtailment of up to 35–40%. In addition, TES uniquely enables seasonal energy shifting, for which no cost-competitive electrochemical alternative currently exists. Despite these advantages, the review identifies persistent gaps related to the limited availability of long-term operational data and the need for empirical validation of hybrid control strategies. Future research should prioritize multi-year field demonstrations, advanced data-driven energy management, and policy frameworks that explicitly recognize thermal flexibility and sector coupling within Renewable Energy Communities. Full article

Silicon-based materials offer exceptional theoretical capacity for lithium-ion batteries (LIBs), but their practical application remains severely hindered by large volume expansion, low electrical conductivity, and unstable solid electrolyte interphase (SEI) formation during cycling. Herein, a binder-free silicon-containing carbon composite anode (denoted as CP-Si@C-4, where CP represents the conductive carbon paper substrate) is designed: carbon constitutes the structural and conductive framework, while silicon nanoparticles serve as a functional alloying component contributing characteristic lithiation/delithiation behavior. This framework comprises a conductive carbon paper (CP) scaffold, a resin-derived carbon matrix for homogeneous silicon dispersion, an interconnected carbon nanotube (CNT) network enabling long-range electron transport, and a conformal chemical vapor deposition (CVD) carbon layer for interfacial stabilization. Rather than simply increasing the overall carbon content, a series of control electrodes with distinct carbon configurations are deliberately designed to decouple the respective roles of bulk stress buffering and particle-level interfacial stabilization during cycling. The results indicate that functionally differentiating and coordinately regulating these two functions is critical for achieving durable binder-free silicon-containing carbon composite anodes. Benefiting from this cooperative multidimensional carbon architecture, the optimized CP-Si@C-4 anode delivers an initial Coulombic efficiency (ICE) of 86.3% and maintains a reversible capacity of ~990 mA h g⁻¹ at 2 A g⁻¹ after 1000 cycles. This work provides a structural design concept for improving long-term stability in binder-free silicon-containing carbon composite anodes. Full article

The growing demand for higher-energy lithium-ion batteries, encompassing consumer electronics, stationary grid storage, and electric mobility to specialized sectors like aerospace, medical devices, and industrial robotics, requires cathode materials that offer higher capacity while remaining cost-effective. This trend has intensified the development of nickel-rich LiNi_1−x−yMn_xCo_yO₂ (NMC) systems. However, high-Ni NMCs such as LiNi_0.9Mn_0.05Co_0.05O₂ (NMC90) suffer from limited thermal and cycling stability. Core–shell architectures using LiNi_0.6Mn_0.2Co_0.2O₂ (NMC622) as a shell can partially alleviate these drawbacks, but structural degradation caused by interdiffusion between the core and shell persists as a major challenge. This study investigates whether a tungsten oxide interlayer can act as a protective barrier that suppresses interdiffusion, stabilizes the crystal structure, and improves long-term electrochemical performance. In this work, NMC cathode powders were synthesized via a one-pot oxalate co-precipitation route, followed by structural characterization using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and ion scattering spectroscopy (ISS). Electrochemical performance, including capacity retention, cycling stability, and internal resistance, was evaluated through galvanostatic charge–discharge (GCD) testing and electrochemical impedance spectroscopy (EIS). The core–shell configuration delivered higher specific discharge capacity compared to the individually synthesized core-only and shell-only reference materials, and the incorporation of a tungsten oxide interlayer resulted in a twofold increase in cycle life. These results demonstrate that tungsten oxide effectively enhances cycling stability by inhibiting core–shell interdiffusion, offering a promising pathway toward more durable high-Ni NMC cathodes. Full article