Redox flow batteries (RFBs) represent a cornerstone for large-scale long-duration energy storage; however, the sluggish redox kinetics of carbonaceous electrodes remain the primary bottleneck for high-power-density applications. Over the past half-century, while heteroatom functionalization has emerged as a pivotal strategy for electrode modification, the field is still challenged by a lack of mechanistic clarity and significant debates regarding the identification of active sites. This scientific impasse stems from the multi-dimensional coupling inherent in electrode modification: a single treatment typically triggers the simultaneous evolution of specific surface area, defects, functional groups, and doping elements, making it exceptionally challenging to decouple individual contributions to catalytic activity. This review aims to resolve these long-standing discrepancies by exploring advancements in heteroatom-functionalized carbonaceous materials and their significant impact on enhancing the electrochemical performance of RFBs. Various substrates are evaluated, ranging from traditional carbon felts, papers, and cloths to emerging electrospun and biomass-derived fibers, etc. Methodologies for their treatment are systematically discussed, including thermal, chemical, and electrochemical techniques. A key focus is placed on the roles of oxygen, nitrogen, and multi-element doping, alongside a forward-looking discussion on single-atom and dual-atom catalysts. The review highlights the current challenges in this field and potential future directions, underscoring the pivotal role of these advanced materials in enhancing the capabilities of RFBs for sustainable energy storage.

The high-rate performance of MoS2 anodes in lithium-ion batteries (LIBs) is constrained by their intrinsic anisotropic ion diffusion behavior within interlayers. Herein, we present a microwave-induced local hotspot strategy achieved through atomic Fe doping in the MoS2 lattice, enabling the synthesis of single-layered MoS2 and realizing isotropic ion transport. Additionally, Fe atoms can be converted into finer Fe nanoparticles (similar to 2 nm) in single-layered MoS2 than in few-layered ones, which can trigger stronger spin-polarized surface capacitance effect demonstrated by in situ magnetometry. Importantly, the Fe nanoparticles can catalyze the formation of a stable LiF-rich solid electrolyte interphase, as confirmed by X-ray photoelectron spectroscopy and ab initio molecular dynamics simulations. These combined advantages equip the MoS2 with ultrahigh-rate lithium storage (870.1 mAh g-1) up to 50 A g-1 (similar to 75 C) in half cells. Notably, 1.6 Ah pouch cells utilizing the MoS2 anode deliver an unprecedented fast-charging capability (81.3% retention) at 3 C. This study develops an ultrahigh-rate MoS2-based anode and elucidates its ion transport enhancement mechanism, laying a theoretical foundation for the development of fast-charging LIBs.

Sodium-ion batteries (SIBs) are widely regarded as a promising alternative to lithium-ion batteries because of their low cost and the abundance of sodium resources. However, although SIBs share similar electrochemical operating principles with lithium-ion batteries, differences in battery materials and operating voltage windows hinder the direct transfer of charging strategies developed for lithium-ion systems. Therefore, to simultaneously achieve high charging rates and enhanced safety, a comprehensive experimental investigation combined with numerical simulations is conducted to analyze the fast-charging behavior of SIBs and to systematically develop an optimized charging strategy. Experimental results demonstrate that heat generation during the fast-charging process of SIBs can be divided into three distinct stages: an initial rapid temperature rise, a subsequent moderate heating stage, and a final sharp temperature increase. Based on these thermal characteristics, an optimal charging strategy incorporating multi-stage charging is developed using an adaptive particle swarm optimization (APSO) algorithm. Experimental validation indicates that, compared with the conventional 3C constant-current charging protocol, the proposed strategy reduces the maximum temperature rise by 2.32 degrees C. Furthermore, the effectiveness of the optimized strategy is corroborated by numerical modeling results. Overall, this study provides a feasible and effective approach for improving fast-charging safety and enhancing thermal management performance in sodium-ion batteries.

Sodium-ion batteries have emerged as a sustainable alternative to lithium-ion batteries, supported by the wide availability and low cost of sodium resources. However, many reported cathodes suffer from low redox potentials, sluggish kinetics, limited cycling stability and temperature sensitivity. Herein, we employed a donor-strength-tuning strategy to design and synthesize an all-donor conjugated polymer cathode, TPPAPZ, via cross-coupling polymerization of a moderate donor (N 1,N 1,N 4,N 4-tetrakis(4-bromophenyl)benzene-1,4-diamine, TPPA-4Br) with a strong donor (5,10-dihydrophenazine, PZ). The combination of two electronically differentiated donor units modulates the frontier electronic structure while maintaining a rigid conjugated backbone, providing a favorable electronic structure for charge transport. The TPPAPZ cathode delivers a high average discharge potential of 3.4 V, exceptional rate capability (128 mAh g-1 at 10 A g-1) and ultra-long cycling stability (50 000 cycles). Notably, it exhibits robust performance across a wide temperature range from -30 °C (118 mAh g-1) to 50 °C (160 mAh g-1). In full cells, TPPAPZ achieves ∼159 mAh g-1. This all-donor polymer design strategy provides a transferable route to mitigate the voltage-capacity trade-off in organic electrodes, enabling the development of long-cycle and wide-temperature sodium dual-ion batteries.

The demand for high-power and fast-charging energy storage systems necessitates sustainable electrode materials that combine ultrafast kinetics, long-term stability, and structural durability. In this work, we present TP-IPA, an imine-linked covalent framework consistent with a 1D covalent organic framework (COF) architecture and featuring a donor-acceptor (D-A) design. It enables ultrafast and reversible anion storage. By integrating a D-A architecture with an ordered 1D nanochannel structure, TP-IPA enhances both electronic conductivity and ion transport. As a p-type cathode material, TP-IPA enables each repeating unit motif to reversibly store two PF6 - anions via oxidation. It delivers high average discharge voltages (similar to 3.58 V vs. Li+/Li and similar to 3.54 V vs. Na+/Na), outstanding rate performance (64 mAh g-1 in Li half-cells and 67 mAh g-1 in Na half-cells at 10 A g-1, equivalent to similar to 120 C), and remarkable cycling stability. Notably, it retains 80% of its initial capacity after 20 000 cycles in Li half-cells and 40 000 cycles in Na half-cells at ultrahigh C-rates (similar to 60 C). This makes TP-IPA one of the most stable and rate-resilient organic cathodes reported to date. This work provides a new strategy for developing next-generation high-power, long-life organic cathode materials.

Proton exchange membrane fuel cells (PEMFCs) are highly susceptible to performance limitations at high current densities due to competing gas and liquid transport mechanisms. While microporous layers (MPLs) reduce contact resistance, they often exacerbate the risk of flooding. This study leverages the topological advantages of highly interconnected cage-like MPLs. By integrating X-ray computed tomography (X-CT) with digital techniques (reconstructed geometry and numerical simulation), it reveals the mass transfer mechanisms within cross-scale composite microstructures. Considering in-situ compression and surface wettability, the research delves into the influence of MPL thickness and crack morphology on multiphase flow dynamics. The results indicate that despite the significant non-steady-state velocity fluctuations and reduced liquid permeability caused by cascading Haines jumps due to increased MPL thickness, its unique high-porosity cage-like network structure still maintains robust oxygen diffusion performance. In-situ compaction further weakens the macropore transport capacity of the gas diffusion layer (GDL), leading to a significant reduction in permeability. In contrast, fractures effectively break through transport bottlenecks. Vertical through-holes maximize oxygen diffusion efficiency through the shortest path effect, while 45 degrees inclined fractures optimize gas-liquid convective permeability while enabling directed high-speed drainage of liquid water. This study elucidates the regulation mechanism of microstructural parameters across scales, providing theoretical guidance for designing next-generation gas diffusion layers that combine high gas-phase diffusion with efficient drainage capabilities.

Aqueous organic redox flow batteries (AORFBs) have been widely recognized as promising solutions for longduration, large-scale energy storage owing to their use of the earth-abundant active materials. However, the low stability of reported extended viologen-based anolytes limits the performance of AORFBs. Here, we report a stable extended viologen-based anolyte with electron-withdrawing imidazole group, N,N'-di [(3-methylimidazolium)ethyl]-4,4'- [1,4-bis(4-pyridyl)benzene] dichloride (DBPyImCl4), for use in AORFBs. This anolyte exhibits a low redox potential of -0.90 V (vs. Ag/AgCl) and an ultra-low permeability of 6.12 & times; 10-12 cm2 s- 1. The assembled AORFB with 0.1 M DBPyImCl4 as the anolyte maintains a capacity retention of as high as 93.3% after 1,216 cycles, resulting in a low decay rate of 0.0055% average per cycle. Post-cycling analysis, including nuclear magnetic resonance, cyclic voltammograms, and high-resolution mass spectrometry, confirms the anolyte's high stability, with its chemical structure fully preserved and crossover absent after long-term cycling. Results from the single crystal structure and theoretical calculations demonstrate that the high stability of the anolyte is attributed to the inductive effect of the electron-withdrawing imidazole group, which weakens the positive charge on the sp3 carbon bonded to the pyridinic nitrogen in DBPyImCl4, thereby suppressing its reactivity and enhancing overall stability. Moreover, a 0.5 M flow battery with 1.0 M electron concentration displays a capacity retention of 95.9% (0.0122% per cycle) after 330 cycles. This work demonstrates a highperformance anolyte for AORFBs and provides an effective strategy for designing highly stable AORFB electrolytes.

The gas diffusion layer (GDL) of proton exchange membrane fuel cells (PEMFCs) is a critical component for the transport of reactants. The efficiency of reactant gas transport remains a major technical challenge in the field today. The anisotropic structure of the GDL gives rise to substantial variations of gas diffusion as well as permeability in different directions. The study employs X-CT technology to obtain the actual GDL's geometry, aiming to investigate a spatial structure at the microscale and its gas transport characteristics. The computational fluid dynamics (CFD) method is used to simulate and study the gas diffusivity and gas permeability of GDL with four different thicknesses. The numerical simulation results show that the diffusivity and permeability in the through-plane (TP) direction are lower than those in the in-plane (IP) direction. Moreover, the effective diffusion coefficient (EDC) decreases with increasing thickness, but is also dependent on the solid fibre structure of GDL. Horizontal alignment of the carbon fibers and the disc-shaped adhesive contributes to the anisotropy between the TP and IP directions, resulting in anisotropic gas transport. The purpose of the study is to supply critical references for manufacturing techniques and optimization of gas transport in GDLs.

O3-type layered oxide cathodes for sodium-ion batteries suffer from severe capacity decay and structural instability, due to Jahn-Teller distortion from Ni2+/Ni3+ redox and detrimental interfacial side reactions. Herein, we report a surface gradient dual-site doping strategy using Sr2+ and Mo6+ to tune the local electronic structure and chemical environment, enabling the in-situ reconstruction of a protective, surface-enriched spinel phase on O3-type layered oxides. This gradient doping drives the directed enrichment and growth of a Jahn-Teller-inactive spinel phase at the surface via local chemical modulation. The resulting surface-spinel reconstruction layer acts as a key barrier, isolating the bulk from direct electrolyte contact, significantly inhibiting irreversible phase transitions, mitigating electrolyte decomposition and transition-metal dissolution, and preserving structural and chemical integrity during prolonged cycling. Benefiting from the dominant role of this surface spinel reconstruction layer, the optimized NFMSM cathode delivers outstanding cycling stability in a pouch-type full cell, retaining 99.8% of its initial capacity after 500 cycles. This work demonstrates that integrating surface gradient doping with intrinsic electronic structure modulation represents a reliable and universal strategy for constructing protective interfaces, which significantly enhances the long-term cycling stability of layered oxide cathodes and promotes the practical application of high-performance sodium-ion batteries.

Abstract Solid-state sodium batteries offer a promising route toward safe and cost-effective energy storage, yet their practical implementation remains limited by the difficulty of coupling fast ion transport with stable electrode–electrolyte interfaces, especially under fast-charging and long-cycling conditions. Here we report a covalent organic framework/poly(sodium acrylate-co-fluorinated ethylene) (COF/PNSE) composite electrolyte developed through synergistic structural and chemical regulation. The aligned nanoporous COF provides continuous Na⁺ transport pathways while mechanically reinforcing the PNSE matrix, delivering an ionic conductivity of 1.2 mS cm −1 at 30 °C. This integrated electrolyte enables robust Na metal compatibility, as demonstrated by symmetric Na cells operating for 6,750 h with low polarization of 85 mV and a critical current density of 1.9 mA cm −2 . Na | |Na 2/3 Ni 1/3 Mn 2/3 O 2 batteries deliver 82.5 mAh g −1 at 1 A g −1 and retain 77.2% capacity after 1,000 cycles at 100 mA g −1 , while maintaining 92.7% retention at 4.2 V over 180 cycles and 83.5% retention at 1 A g −1 over 2,000 cycles. Ah-level pouch cells further retain 87.3% capacity after 488 cycles at 1 A. Mechanistic analyses reveal that the COF framework guides uniform Na deposition and promotes dual-gradient NaF/Na 2 O-rich interphases, suppressing dendrite growth and stabilizing both electrodes. These findings inform future composite electrolyte design for solid-state sodium batteries.

The performance of solid oxide electrolysis cells (SOECs) is closely related to its flow channel structure, stoichiometric ratio, and operating temperature. In this study, multiphysics numerical models were developed, incorporating coupled heat and mass transport alongside electrochemical reaction processes. The model validity was confirmed by comparing simulated results with experimentally measured I-V curves. The impacts of the fuel-to-air stoichiometric ratio (F:A from 2:1 to 2:4), channel aspect ratio (L:W from 1:1 to 4:1), temperature (from 873.15 K to 1073.15 K), and flow arrangements (co-current vs. counter-current) on the performance of a single-channel electrolyzer were systematically investigated, complemented by an analysis of multi-channel behavior under cross-flow conditions. The findings reveal that among the investigated parameters, temperature exerts the most significant influence on cell performance. Increasing the temperature facilitates the substitution of electrical energy with thermal energy, reducing the cell voltage from 1.5364 V to 1.1142 V at 1.2 A/cm2. Furthermore, varying the stoichiometric ratio effectively improves the oxygen partial pressure in the catalyst layer, thereby reducing concentration polarization. At the same current density, the required cell voltage decreased from 1.5364 V to 1.5153 V. Increasing the channel aspect ratio improves mass transport, reducing the required cell voltage from 1.5444 V to 1.5053 V. In contrast, flow arrangements were found to have a negligible impact on overall performance, though the counter-flow arrangement demonstrated marginal superiority over the co-flow arrangement.

Efforts to increase power density, primarily motivated by the need to reduce capital cost, have become a central focus in research on redox flow batteries (RFBs). However, the increase in power density intensifies the parasitic hydrogen evolution reaction (HER) at the negative electrode, posing a significant operational challenge for RFBs. Conventional engineering countermeasures frequently involve lowering the charging cut-off voltage to mitigate HER. However, this approach reduces electrolyte utilization, ultimately leading to increased electrolyte costs. To enable more rigorous control strategies and elucidate the mechanistic basis of hydrogen evolution, a three-dimensional model incorporating HER phenomena in vanadium RFBs is developed in this work. The numerical simulation and accompanying experiments indicate that HER displays pronounced spatial heterogeneity across the porous electrode, producing hotspots for gas formation and accumulation, where active-species concentrations are low and under-rib convection is weak. Enhancing mass transport and improving the uniformity of active-species distribution are shown to substantially mitigate HER. We find that increasing the electrolyte flow rate from 1 to 11 mL min(-1) cm(-2) reduced the hydrogen gas fraction within the electrode from similar to 1.2% to similar to 0.4% while raising state of charge (SOC) from 0.8 to 0.9, a strategy that suggests simultaneous improvement of SOC and suppression of the HER side reaction is achievable, but this method incurs higher pumping losses. Moreover, HER is sensitive to other operating conditions (e.g., current density and cut-off voltage), which similarly imply trade-offs between instantaneous power density, electrolyte utilization, and parasitic losses. Collectively, the model and supporting experiments provide mechanistic insight into HER behavior during RFB operation, offering guidance to mitigate these trade-offs and minimize parasitic reactions, thereby enhancing overall system efficiency and durability.

Transition-metal-based hydrogen evolution reaction (HER) catalysts lose activity at high current densities because of structural degradation, agglomeration and gas-bubble accumulation, which ultimately limit durability. Here we construct a multiscale cathode, Ni4Mo/MoO2@GF-NVG, in which Ni4Mo/MoO2 are integrated into nitrogen-doped vertical graphene (NVG) grown on graphite felt (GF) via a spatially confined Joule-heating strategy. The vertically aligned NVG network supports uniformly dispersed sub-20 nm Ni4Mo/MoO2 nano-particles, forms an embedded, low-resistance interface between the catalyst layer and the graphite felt current collector, and provides open, mechanically robust channels for rapid bubble disengagement and electrolyte replenishment, thereby effectively coupling the engineered alloy/oxide interfacial active sites with efficient charge and mass transport. Spectroscopic analyses show a Mo4+-dominated oxide component and reduced Ni-Ni and Ni-Mo coordination numbers at the Ni4Mo/MoO2 heterointerfaces, indicating nanoscale alloy/oxide junctions with under-coordinated Ni and Mo sites in the heterostructure. Density functional theory (DFT) calculations further demonstrate that these alloy/oxide interfaces substantially lower the Volmer water-dissociation barrier and yield hydrogen-adsorption free energies close to thermoneutral values compared with the individual Ni4Mo and MoO2 phases. Benefiting from this architecture, Ni4Mo/MoO2@GF-NVG requires an overpotential of 19 mV to reach 10 mA cm-2 and sustains 1.65 V at 500 mA cm-2 for 600 h in an AEMWE cell with negligible voltage increase, providing design guidelines for designing durable platinum-group-metal-free (PGM-free) cathodes for alkaline membrane electrolysis.

The lithium plating reaction in graphite electrodes acts as a root cause for the accelerated degradation and the internal short circuits in lithium-ion batteries. Here, an electrochemical model based on multi-scale microstructural images was established to identify lithium plating-stripping processes, thereby supporting the predictive outcomes of electrochemical monitoring techniques. Experiments revealed that the open-circuit voltage differential curve (dOCV/dt) led to ambiguous delineation of the safe state-of-charge (SOC) operating range. The established lithium plating-stripping model was used to compare with experimental results, revealing the dynamic evolution of electrode-scale kinetics and quantified the impact of lithium metal residue on electrode performance. Ex situ X-ray computed tomography (XCT) captured micrometer-resolution microstructural details of graphite electrodes and plated lithium, enabling further correlation of spatially heterogeneous lithium plating-stripping reactions with electrode microstructure. The sensitivity of lithium plating to electrode microstructure was examined at the particle scale, attributed to competition between electrode kinetic rates and active reaction areas. Theoretical mechanism analysis and experimental results from high-energy-density electrodes demonstrated that positioning small particles on the current collector side effectively mitigates solid-state diffusion polarization while confining side reactions to a limited area. The integration of experiments and multiscale modeling elucidates the relationship between lithium plating-stripping reactions and electrode structure, providing mechanistic insights for similar structural optimization designs.

Carbon corrosion induced by anode localized flooding severely compromises the durability of proton exchange membrane fuel cell (PEMFC). Limited by the computational stability and efficiency, existing simulations are always in 2D or single-channel scales, which overlooks the influence of the actual flow field structure in commercial PEMFC on carbon corrosion behavior. In this study, a performance-coupled 3D carbon corrosion model is established to investigate the carbon corrosion behavior and performance degradation in a 306 cm2 commercial-scale PEMFC under anode localized flooding conditions. The research demonstrates that the carbon corrosion zone exhibits a quasi-trapezoidal distribution influenced by hydrogen transport and in-plane proton conduction. Carbon loading undergoes rapid loss during the initial flooding phase, followed by a gradual leveling off. After 120 min of local flooding, the PEMFC exhibits an electrochemically active surface area (ECSA) loss of 23.97 % and an output power loss of 16.83 %. This model provides deeper insights into carbon corrosion behavior under localized flooding in large-scale PEMFC and offers a valuable reference for formulating carbon corrosion mitigation strategies.

The vanadium‑oxygen fuel cell is a liquid-fuel-based electrochemical energy conversion system with considerable potential for energy storage and renewable energy integration. However, its power density remains substantially lower than that of vanadium redox flow batteries with the same vanadium anode and hydrogen‑oxygen fuel cells with the same oxygen cathode, hindering its broader development and application. To address this challenge, a numerical model, supported by targeted experimental validation, was developed to elucidate the origins of polarization losses and identify strategies for cell performance optimization. Guided by the numerical insights, bismuth nanoparticles are electrodeposited onto the electrode fibers, significantly enhancing anodic reaction kinetics and reducing the anode loss by nearly 83%. The optimized design enabled the cell to attain the peak power density of 213 mW cm−2, corresponding to an approximate 177% increase over the control group. This research offers a detailed comprehension of the electrochemical behavior and polarization mechanisms in vanadium‑oxygen fuel cells and offers practical design strategies to improve performance.

Redox flow batteries, by virtue of their advantages in power/capacity decoupling, high safety, and long cycle life, have become a strategic support for long-duration energy storage systems; however, capacity degradation remains a bottleneck for their commercialization. This review systematically identifies the multi-dimensional mechanisms of capacity degradation: including volume imbalance caused by transmembrane migration, inactivation and decomposition of active species, electrode degradation, and valence imbalance induced by side reactions. Targeting these challenges, the review deeply explores recovery strategies from physical repair to intelligent scheduling: covering the research and development of high-selectivity membranes, precise regulation of valence states, functionalized repair of electrodes, and model-driven predictive pathways integrating digital twins. Finally, current challenges such as characterization limitations and incomplete recovery rates are summarized, and future development directions for capacity recovery are envisioned. This review aims to provide a theoretical basis and technical guidance for extending the system cycle life of flow batteries and improving capacity recovery efficiency.

The gas diffusion layer (GDL) is a critical component for gas transport in proton exchange membrane fuel cells (PEMFCs). Gas transport efficiency significantly impacts PEMFC performance. This study employs integrated micro-computed tomography (Micro-CT) for 3D reconstruction of the GDL and utilizes computational fluid dynamics (CFD) to investigate gas diffusion and convection in GDLs with varying perforation/thickness ratios. Results indicate that perforations enhance the effective diffusion coefficient (EDC) of GDLs, while GDL thickness has minimal impact on EDC. EDC variations are primarily influenced by internal geometric structures. The anisotropy arising from fiber orientation during carbon paper manufacturing results in higher diffusion rates in the in-plane (IP) direction than in the through-plane (TP) direction. Perforations reduce inlet pressure and improve gas flow, thereby increasing GDL permeability; conversely, permeability decreases with increasing GDL thickness. High-velocity regions in the GDL correspond to large pore areas, indicating that pore distribution influences gas transport. This study aims to elucidate the fundamental mechanisms of gas transport in GDLs as functions of thickness and perforation, thereby providing crucial theoretical guidance for GDL design.

Water in Proton Exchange Membrane Fuel Cells (PEMFCs) holds significance and complexity. The study of water is crucial for enhancing the efficiency and extending the lifespan of the batteries. This study used micro-CT technology to obtain tomographic images of the gas diffusion layer (GDL) in PEMFCs. Subsequently, the samples were reconstructed in three dimensions using Avizo, and the internal fluid flow in the GDL was simulated using the Volume of Fluid (VOF) method. The local and average porosities of all sample types were calculated, providing insight into the distribution of the internal pore structure of the GDL. Analyzed the impact of the pressure difference at the inlet and outlet(Delta P), contact angle, and the thickness of the model on the flow of liquid. The research results indicate that for the TGP-H-60 model of GDL, the Delta P must be at least 6 kPa to allow liquid water to flow from one end to the other. The contact angle within the GDL significantly impacts the removal of liquid water. In practical applications, the selection of GDL thickness must ensure mechanical strength while also considering fluid transport efficiency to enhance battery performance. An overly thick can make the flow of water more difficult, resulting in flooding phenomena.

Thermal runaway (TR) is a severe challenge to the widespread commercial adoption of high energy-density lithium-ion batteries (LIBs). Nonetheless, the current strategies lack responsiveness for both extreme heat dissipation and explosion suppression. Here, a thermal safety protection strategy based on liquid immersion cooling (LIC) is proposed. The peak temperature of overcharge-induced TR is decreased below 300 degrees C through boiling heat exchange of FS49, rapidly (3 min) stabilizing the LIB temperature around 49 degrees C. Simultaneously, critical radicals are captured by FS49 in the combustion chain reaction, reducing emissions of combustible toxic gases by approximately 62.65%. This effectively prevents LIB explosions and secondary re-ignition disasters. Surprisingly, when applied as 1 mm interlayers between cells for a pack with four LIBs, the FS49 not only suppresses the TR propagation but also maintains the adjacent LIB temperature at 53.89 degrees C. Additionally, it is further demonstrated that the thermal safety of a large-scale 36-cell LIB pack through finite volume method simulations. This strategy can represent a critical step forward in enhancing the safety performance of electric vehicles and grid-scale energy storage systems.