As an efficient large-scale energy storage technology, flow batteries demonstrate broad application prospects in the fields of renewable energy integration and grid peak shaving. Nevertheless, challenges such as sluggish electrode reaction kinetics, low energy efficiency, and poor cycling stability continue to hinder the further development and widespread adoption of flow batteries. Defect engineering is an effective strategy for modulating the physicochemical properties of materials and offers a novel way to improve the overall performance of flow batteries. Against this backdrop, this review investigates how defect design affects the electronic structure, reaction kinetics, ion transport properties, and structural stability of electrode materials. This study highlights that integrating defect engineering with catalytic electrode design can effectively modulate the performance of flow batteries. This paper provides a systematic review of the research progress and application outcomes of defect engineering in four types of flow batteries: all-vanadium, polysulfide-iodide, zinc-based, and organic flow batteries. This further validates the feasibility of this strategy. Furthermore, the challenges and future research directions in this field are outlined. A comprehensive analysis of existing studies demonstrates that defect engineering, when designed with a specific purpose in mind, can significantly improve the overall performance of flow batteries. This provides a scientific basis and technical support for the rational design of high-performance flow battery systems.

A wireless stimulation platform that is based on a bioresorbable phototransistor can provide precise, programmable and multi-site electrotherapy through tissue-penetrating optical modulation.

Aqueous zinc-ion batteries (AZIBs) are promising for their inherent safety and low cost. However, the inevitable hydrogen evolution reaction (HER) within the aqueous electrolytes corrodes the zinc anode and promotes dendrite growth, thereby shortening cycling life. Gel polymer electrolytes (GPEs), with their abundant hydrogenbonding networks, can suppress HER via hydrogen-bonding networks that reduce water activity. In this study, we designed a mesoporous silica-reinforced dual-network interpenetrating polymer electrolyte (PAN/SiO2-PAMCS) to improve overall performance. It combines an electrospun polyacrylonitrile (PAN) skeleton with a cross-linked network of acrylamide (AM) and chitosan (CS) formed via Michael addition. The incorporated SiO2 significantly improves mechanical strength, and its uniform mesoporous structure promotes homogeneous ion transport, unlike conventional fillers. Polyacrylamide (PAM) contributes excellent tensile strength, ionic conductivity, and mechanical robustness, while the hydrophilic groups of CS effectively reduce water activity and mitigate HER. The optimized electrolyte demonstrates outstanding comprehensive properties: a maximum tensile force of 82 N and an ionic conductivity of 1.82 x 10-3 S cm-1 at room temperature (25 degrees C). Symmetric Zn cells using this electrolyte achieved stable zinc plating/stripping for up to 2000 h, while Zn||VO2 full cells maintained over 85 % capacity retention after 200 cycles. Overall, this study significantly enhanced the mechanical properties and electrochemical stability while maintaining high ionic conductivity by constructing a double-network interpenetrating structure electrolyte with mesoporous silica. It provides an effective electrolyte design strategy for the development of long-life and high-safety aqueous zinc-ion batteries.

Metal single-atom catalysts (SACs) offer exceptional atomic efficiency and remarkable properties, making them highly valuable for energy and environmental applications. However, existing SAC preparation methods face challenges, such as the need for high temperatures or limitations in metal loading. In this study, we present a room-temperature synthesis strategy for stable SACs with high metal loadings (>10 wt %), achieved through electrochemical redox reactions within lithium-ion batteries. The reaction mechanism was thoroughly elucidated, revealing that bulk metallic compounds (denoted as MaXb, where M represents a metal and X is F, S, or O) disintegrate from the millimeter scale down to single atoms at room temperature. This process is driven by lithiation-delithiation-induced grain refinement and the dissolution of metals, which are subsequently captured by the substrate. The resulting single-atom catalyst (e.g., Cu SAC) demonstrates outstanding reactivity for electrocatalytic CO2 reduction, showcasing excellent electrochemical stability and superior performance. This room-temperature redox method is versatile and compatible with a wide range of metals and supports, highlighting its potential for broad applications in sustainable catalytic technologies.

The automotive industry is currently undergoing a profound transformation, with sustainability emerging as a core tenet of this evolution [...]

Redox flow batteries (RFBs) have demonstrated considerable potential for application prospects in the domain of large-scale energy storage. This potential can be attributed to their notable advantages, which include the decoupling of power and capacity, a prolonged cycle life, and a high level of safety. However, the enhancement of their energy efficiency and power density remains significantly constrained by critical issues, including sluggish reaction kinetics, the shuttle effect of active species, and inadequate interfacial stability. In recent years, heterojunctions have emerged as an efficient interfacial engineering strategy, providing novel solutions for enhancing the key performance of RFBs. This enhancement is achieved through the reconstruction of the interfacial electronic structure and modulation of the built-in electric field. This study provides a comprehensive review of the research progress related to heterojunctions in RFBs. The study focuses on summarizing the construction strategies and action mechanisms of heterojunction electrodes and heterojunction ion exchange membranes. It also discusses the regulatory effects of these materials on redox reaction kinetics, ion transport behavior, and cycling stability of RFBs. Additionally, the development trend of machine learning-assisted rational design of heterojunctions is discussed in detail. The objective of this work is to establish a theoretical framework and to elucidate the research insights pertinent to the precision design and engineering application of heterojunction materials in high-performance RFBs.

Grain boundaries (GBs), which are inherent and unavoidable microstructural features in polycrystalline materials, play a decisive role in determining the overall performance of solid-state electrolytes (SSEs). Although SSEs hold great promise for enabling safer and higher-energy-density all-solid-state lithium batteries (ASSLBs), their functional properties are largely dominated by GBs. These GBs severely impede ionic transport, promote lithium dendrite propagation, and accelerate interfacial degradation, thereby compromising the performance and lifespan of the cell. However, despite the significant research on GB regulation, a comprehensive review of their formation mechanisms and improvement strategies specific to ASSLBs is still lacking. In this review, we highlight the formation mechanism of GBs and the effect of their fundamental physical and electrochemical characteristics on the safety and electrochemical performance of SSEs, integrating recent insights from experimental and computational analyses. The effective strategies for suppressing and mitigating GB-related limitations are summarized to enhance the performance of SSEs, along with proposed future research directions in GB engineering. By consolidating current knowledge, this review aims to connect fundamental understanding to practical battery design and provide actionable guidance for addressing the GB challenges in ASSLBs.

The evaluation of the efficacy of electrochemical treatment of heavy-metal-bearing wastewater has evolved from a focus on peak removal in simplified solutions to a consideration of selectivity, stability, and product value to withstand the complex chemical processes occurring in industrial streams. The present review employs a systematic approach to evaluate the extant literature on the subject. This approach involves a series of steps, including decomposition, capture, separation/concentration, and purification/recovery. The review places a premium on studies that report on real or chemically complex wastewaters, metal speciation or release, normalized energy use, continuous operation, effluent quality, product purity, and residual-stream fate. Ligand-rich Cu- and Ni-bearing wastewaters serve as the primary evidence base due to their combination of strong complexation, competing ions, high salinity, organic interference, and relatively mature recovery-oriented data. These wastewaters also expose failure modes relevant to other heavy-metal systems. Across a range of electrochemical processes, including electrooxidation, electroreduction, electrocoagulation, electrodialysis, bipolar membrane electrodialysis, capacitive deionization, and electrodeposition, the central finding is that removal, recovery, and product-end validation are distinct claims requiring different evidence. The efficacy of removal is substantiated by engineering evidence when it is associated with species transformation, stable stream control, energy and boundary accounting, product purity, impurity carryover, and the fate of residual liquid or solid streams. The resulting evidence-oriented reporting framework is intended to translate laboratory electrochemistry into continuous, resource-recovery-oriented treatment of complex heavy-metal wastewater.

Understanding how Cu catalysts fail under operating conditions is essential for durable CO2 electroreduction. Here we integrate theoretical calculations, electrochemical analysis, and time-evolving structural monitoring to link metal-support interaction (MSI) with degradation mode. Calculations reveal that shrinking Cu dimensions strengthens interfacial bonding through enhanced charge transfer and electronic coupling. Experimentally, two model catalysts, larger Cu nanoparticles (weak MSI) and highly dispersed Cu nanoclusters (strong MSI) on identical carbon spheres, exhibit comparable initial activity but fundamentally different lifetimes. Weak-MSI nanoparticles accumulate defects and undergo a rapid collapse of long-range order and fast deactivation, whereas strong-MSI nanoclusters resist atom mobility and instead follow a slow, quasi-equilibrated surface reconstruction that sustains activity for over 180 h before facet-level erosion diminishes selectivity. MSI thus acts as a kinetic lever that bifurcates the reconstruction trajectory, suggesting interface engineering as a route to steer inevitable degradation into slower, more manageable modes.

ABSTRACT Sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs) have emerged as significant contenders for large‐scale energy storage technology due to their substantial resource reserves and cost effectiveness. However, their large‐scale development is hindered by several key challenges, including the structural degradation of electrode materials during cycling, slow kinetics, and instability at the electrode–electrolyte interface. Entropy‐regulation strategies, particularly medium‐to‐high‐entropy designs, represent an emerging paradigm in materials design. The integration of multiple components, with the aim of leveraging their synergistic effects, presents a novel approach to address the aforementioned challenges in a systematic manner. It has been demonstrated that, owing to its elevated configurational entropy, this strategy accomplishes two objectives: first, it provides thermodynamic stabilization of the crystal structure, and second, it suppresses undesirable phase transitions. Additionally, it induces kinetic effects that result in slow diffusion, thereby effectively delaying element migration and side reactions. Concurrently, entropy regulation fosters the establishment of a stable interfacial film at the electrode‐electrolyte interface, thereby enhancing interfacial ionic transport efficiency and chemical stability. This paper systematically reviews the mechanistic insights and research progress of entropy‐regulation strategies in cathode materials, anode materials, and interface engineering for SIBs and PIBs, and outlines future directions for this field.

To improve the compatibility, photothermal responsiveness, and batch stability of Karstedt catalyst microcapsules, Karstedt/silicone wax/PDA microcapsules were prepared by a melt-dispersion method combined with insitu PDA coating. In this system, silicone wax served as a double-layer wall material, while PDA acted as a photothermal layer. The morphology, structure, thermal stability, photothermal behavior, catalyst release, curing kinetics, and mechanical properties were characterized by SEM, FTIR, TGA, DSC, ICP-OES, infrared thermal imaging, and tensile testing. The prepared microcapsules showed regular morphology, relatively uniform particle-size distribution, and good coating integrity, with a photothermal conversion efficiency of 25.39%, stable photothermal response after five heating/cooling cycles, and a room-temperature latency period exceeding 30 days. The microcapsules exhibited a two-stage release behavior, namely slow Pt accumulation followed by accelerated release, which was attributed to the temperature-induced softening/melting of the silicone wax shell and reduced diffusion resistance. The curing kinetics conformed to an autocatalytic model. Compared with neat Karstedt-cured silicone rubber, the silicone rubber cured with Karstedt/silicone wax/PDA microcapsules showed an increase in elongation at break from 252.31% to 287.81%, while the tensile strength decreased from 0.465 to 0.310 MPa. This work provides a simplified strategy for preparing latent photothermally responsive Karstedt catalyst microcapsules for light-controlled curing of silicone rubber.

Abstract The development of high-performance cathode materials is crucial for advancing sodium-ion batteries (SIBs). This study investigates the impact of La doping on the structural and electrochemical properties of a P2-type layered oxide cathode material, Na0.7Fe0.14Cu0.09Mn0.77O2 (FCM). X-ray diffraction confirmed successful incorporation of La3+ into the crystal lattice without altering the primary P2 structure, while also inducing an expansion of the Na+ layer spacing. Scanning electron microscopy and transmission electron microscopy revealed well-defined particle morphology with homogeneous element distribution. Electrochemical tests demonstrated that moderate La doping (2%, FCML-2) significantly enhanced the rate capability and cycling stability. The FCML-2 delivered a high discharge capacity of 137.3 mAh g−1 at an ultra-high rate of 10 C, vastly superior to the 111.0 mAh g−1 of FCM. Furthermore, FCML-2 exhibited an exceptional capacity retention of 90.8% after 500 cycles at 1 C, compared to 56.3% for FCM. These improvements are attributed to the “pillar effect” of La3+, which stabilizes the crystal structure and widens Na+ diffusion pathways. This work underscores the dual benefits of La doping in enhancing ionic kinetics and structural integrity, presenting an effective strategy for developing advanced cathode materials for SIBs.

To boost supercapacitor (SC) energy density, we introduced redox-active molecules into an aqueous H2SO4 electrolyte. Using retrosynthetic analysis, we identified aminoquinones, specifically triaminochlorobenzoquinone (TACBQ), as promising candidates. Characterization via elemental analysis, Fourier Transform Infrared Spectrometer (FT-IR), nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS) confirmed structure of TACBQ. We incorporated varying TACBQ concentrations into 1 M H2SO4, finding that 2 mg mL-1 optimized SC performance. Compared to 1 M H2SO4 alone, the 2 mg mL-1 TACBQ system showed marked improvements: in a three-electrode setup, specific capacitance increased from 141 F g-1 to 358 F g-1 at 1 A g-1. In a two-electrode quasi-solid-state device, capacitance rose from 27 F g-1 to 35 F g-1 at 1 A g-1, the voltage window expanded from 1 V to 1.6 V, and energy density improved from 3.75 Wh kg-1 to 12.43 Wh kg-1 at 1000 W kg-1. After 10,000 cycles at 10 A g-1, the device retained 84 % capacity.

The "shuttle effect" and slow reaction kinetics caused by the diffusive polysulfides (LiPSs) in lithium-sulfur batteries have seriously hindered the superiorities of high theoretical capacity and energy density of sulfur cathode. Metal compounds serve as cathode carrier materials for lithium-sulfur batteries can adsorb LiPSs and accelerate the sulfur redox reaction. Compared with monometallic systems, bimetallic components usually expose richer active sites, which facilitates the kinetics of LiPSs during the redox process. However, due to the limitation of morphology and structure, the catalytic capacity of single metal atom and the synergistic effect between bimetal atom are still not fully utilized, leading to the still poor reaction kinetics. Especially, their application effect in thick electrode with high sulfur load is significantly reduced. In this study, chemical etching reaction was utilized to convert zeolitic imidazolate framework (ZIF) 67 into a polyhedral hierarchical structured material stacked with layered double hydroxide (NiCo-LDH) nanosheets, and based on this, it was transformed into nickel cobalt sulfoselenide (NiCoSSe) with quaternary hierarchical structure. The bimetallic sulfoselenide obtained by this strategy retain the high specific surface area of the ZIF structure, thus providing more active sites for adsorption of LiPSs and catalyzing sulfur redox. Importantly, it was demonstrated by density-functional theory (DFT) calculations that, selenium doping can further enhance the interaction between Ni and Co atoms in NiCoSSe, which promotes the conversion of LiPSs and significantly improves the redox kinetics of the battery. An initial specific capacity of up to 1093.4 mAh g-1 at a current density of 0.1C as well as a capacity retention of 98.2 % after 500 charge-discharge cycles at a current density of 2C were obtained based on the cathode with NiCoSSe carrier. By systematically investigating the synthesis of bimetallic sulfoselenide compounds and their enhancement effects on the reaction kinetics of lithium-sulfur battery cathode, this study will provide a detailed reference for the conformational relationship between the structure of quaternary NiCoSSe materials and electrochemical performance.

High-voltage lithium metal batteries (LMBs) have emerged as ideal candidates for achieving high-energy-density energy storage devices. Notably, high-reactive lithium metal and high-voltage transition metal oxide cathodes require electrolytes with superior electrochemical stability and interfacial compatibility. Herein, a solvent chemistry electrolyte design strategy is proposed that a weakly-solvated fluorinated bis(2,2,2-trifluoroethyl) carbonate (TFEC) was introduced into carbonate electrolyte for enhanced high voltage performance. The weakly solvated TFEC shows weak interaction with lithium ions, facilitating ionic transport and improving the interfacial wettability. More importantly, the thin and even TFEC-derived LiF-rich interface retards interfacial side reactions between the electrolyte and electrodes, enabling LMBs to cycle stably. Herein, the Li symmetric cells maintain stable operation for 400 h. even at a high cut-off voltage of 4.5 V, Li full cells demonstrate the excellent specific capacity of 158.1 mAh g-1 and cycle stability with capacity retention of 90.2 % over 100 cycles. The innovative strategy of self-adapting interface design is broadly applicable, providing new insight into designing stable and high-performance LMBs.

Designing a stable electrode-electrolyte interface (EEI) is critical for developing lithium metal batteries with high energy density, enhanced safety, and broad applicability. Lithium nitrate (LiNO3) is an attractive sacrificial additive for lithium metal anode, while its poor solubility in high-voltage-resistant ester/nitrile electrolytes severely limits its utility. To solve it, a novel suspension electrolyte strategy is proposed that uniformly disperses LiNO3 particles in an ester/nitrile mixed electrolyte to stabilize the electrode interface. The suspended LiNO3 particles exhibit dual functionality: LiNO3 enhances the compatibility between the electrode and the electrolyte by affecting the Li+ solvation environment and preferentially adsorb on the electrode surface; moreover, the in situ formed LiNxOy-rich EEI by LiNO3 decomposition with accelerated Li⁺ transport kinetics, effectively suppresses parasitic reactions and improves rate performance. The optimized electrolyte makes Li||NCM523 battery run stably for 100 cycles with a high capacity retention of 90.05% at 60 °C and stably operated at low temperature (-10 °C). Moreover, the electrolyte shows excellent electrochemical stability at a high-voltage of 4.5 V. This work presents a dual-strategy advancement featuring wide-temperature electrolyte formulation and precision interface engineering, synergistically achieving high-specific-energy lithium metal batteries.

The development of efficient and cost-effective energy storage systems is crucial for addressing the intermittency of renewable energy sources. Redox flow batteries (RFBs) have emerged as promising candidates for large-scale energy storage due to their scalability and flexibility. However, the sluggish kinetics of polysulfide redox reactions at conventional carbon-based electrodes limit their performance. In this study, we report a novel copper sulfide (CuS) nanoflower-modified carbon felt (CuS-CF) electrode for polysulfide–ferrocyanide redox flow batteries (PFRFBs). The CuS nanoflowers were synthesized via a low-temperature water bath method, exhibiting a highly ordered hexagonal crystal structure with minimal defects. The CuS-CF composite electrodes demonstrated superior electrochemical performance, including enhanced conductivity, reduced overpotential, and improved reversibility of polysulfide redox reactions. At a current density of 120 mA cm−2, the CuS-CF composite electrodes achieved an energy efficiency of 68.9

Volume expansion during repeated cycling is the primary cause of degradation of SiOx anodes, impeding their practical application in next-generation high-energy-density lithium-ion batteries. Herein, a self-healing polymer binder incorporating both dynamic covalent and hydrogen bonding interactions is developed to accommodate volume changes and enhance the stability of SiOx anodes. This self-healing binder (PPC) is prepared through the physical cross-linking of poly(α-lipoic acid) (PLA) and poly(acrylic acid) (PAA), together with the ion-conducting choline chloride (ChCl), which induces the formation of a network structure. Physical cross-linking effectively dissipates the stress and strain induced by the SiOx expansion. And in this self-healing network, rigid PAA provides structural integrity, whereas elastic PTA with dynamic S-S bonds serves as a buffer, enabling a tunable balance between mechanical strength and flexibility to accommodate lithiation-induced volume expansion. As expected, the SiOx electrode with the PPC binder demonstrates a decent performance with a specific discharge capacity of 998.6 mAh g-1 after 200 cycles at 2000 mA g-1, corresponding to a capacity retention of 85%. Meanwhile, the binder enabled the SiOx||NCM622 full cell to achieve remarkable capacity retention of 95.1% after 100 cycles at 0.5 C.

Lithium metal batteries (LMBs) are expected to increase energy density due to the high capacity and low electrode potential of lithium metal. However, lithium dendrite growth and organic liquid electrolytes exacerbate the risk of thermal runaway. To improve the safety of the battery, a multifunctional flame-retardant separator was developed through the synergistic effect of decabromodiphenyl ethane (DBDPE)/Al2O3 nanoparticle composite modification. Among these, DBDPE acts as a flame retardant to reduce the combustibility of the battery, while Al2O3 with high mechanical strength inhibits dendrite growth, and its amphiphilic nature favors the uniform distribution of lithium ions. Thus, a multifunctional flame-retardant separator simultaneously achieves excellent flame suppression, enhanced thermal conductivity (71.3 mW·m-1 k-1), and excellent electrochemical performance. Lithium (Li) symmetrical batteries based on this separator stably run over 500 h at a current density of 0.5 mA·cm-2, and Li/LiFePO4 batteries retain a capacity of 138 mAh g-1 capacity over 100 cycles at a rate of 0.5 C. This flame-retardant separator design, leveraging synergistic regulation of microstructure and thermal properties, provides a groundbreaking roadmap for suppressing thermal runaway while maintaining electrochemical performance, thereby redefining safety paradigms for next-generation high-energy-density battery systems.

How to further improve the fuel economy and emission performance of hybrid vehicles through scientific and reasonable energy management strategies has become an urgent issue to be addressed at present. This paper proposes an energy management model based on speed prediction using Long Short-Term Memory (LSTM) neural networks. The initial learning rate and dropout probability of the LSTM speed prediction model are optimized using a Double Deep Q-Network (DDQN) algorithm. Furthermore, the LSTM speed prediction function is implemented within a Model Predictive Control (MPC) framework. A fuzzy logic-based driving mode recognition system classifies driving cycles and identifies real-time conditions. The fuzzy logic-based driving mode is used to divide the typical driving cycle into different driving modes, and the real-time driving modes are identified. The LSTM-MPC method achieves low RMSE across different prediction horizons. Using predicted power demand, battery SOC, and real-time power demand as inputs, the model implements MPC for real-time control. In our experiments, four prediction horizons (5 s, 10 s, 15 s, and 20 s) were set. The energy management strategy demonstrated optimal performance and the lowest fuel consumption at a 5 s horizon, with fuel usage at only 6.3220 L, saving 2.034 L compared to the rule-based strategy. Validation under the UDDS driving cycle revealed that the LSTM-MPC-DDQN strategy reduced fuel consumption by 0.2729 L compared to the rule-based approach and showed only a 0.0749 L difference from the DP strategy.