Hierarchical core-shell heterostructures are effective for enhancing supercapacitor performance, yet the role of electrodeposition time in governing shell morphology and interfacial coupling remains underexplored. Herein, we systematically investigate the time-dependent evolution of Co3O4@NiCo-LDH core-shell nanoarrays. By optimizing the electrodeposition duration to 500 s, we obtain a well-defined nanosheet shell (NC-3) that provides abundant active sites, shortened ion diffusion paths, and strong electronic interaction with the Co₃O₄ nanowire core. The NC-3 electrode achieves a high specific capacitance of 2647.5 F g⁻¹ at 1 A g⁻¹ with excellent cycling stability. An assembled asymmetric supercapacitor delivers an energy density of 86 Wh kg⁻¹ at 800 W kg⁻¹ and retains 89.8% of its initial capacitance after 10,000 cycles. This work highlights the critical role of deposition time in tailoring core-shell architectures and provides a controllable electrodeposition route for high-performance energy storage.

Bismuth vanadate (BiVO4) is a promising photoanode material for photoelectrochemical (PEC) water splitting. However, its performance is often constrained by inefficient charge separation and sluggish surface reaction kinetics. Herein, we report a facile and scalable modified successive ionic layer adsorption and reaction (SILAR) method to fabricate BiVO4 photoanodes, circumventing the equipment-intensive electrodeposition step conventionally used for BiOI template preparation. This approach involves the electroless deposition of BiOI precursor templates on FTO substrates, followed by conversion to porous monoclinic BiVO4. By systematically adjusting the SILAR precursor concentration from 2 to 9.5 mM, we established its critical influence on the grain size and porous network interconnectivity of the resulting BiVO4 films. At the optimal concentration of 6.5 mM, the BiVO4 photoanode achieves a considerable photocurrent density of 2.41 mA & sdot;cm-2 at 1.23 V vs. RHE under AM 1.5 G illumination. This value represents a highly competitive performance for undoped, cocatalyst-free BiVO4 photoanodes prepared by the SILAR method. Comprehensive PEC analyses reveal that this considerable performance originates from a synergistic combination of enhanced carrier dynamics: an increased carrier density, a substantially reduced charge transfer resistance (by 46%), and a prolonged carrier lifetime (a 2.5-fold increase). These improvements are attributed to the formation of a highly interconnected porous framework composed of ultrafine grains, which provides a significantly enlarged electrochemically active surface area. This work presents a straightforward and scalable strategy for fabricating high-performance BiVO4 photoanodes through precise parameter control in the SILAR process, offering valuable insights for the controlled synthesis of other metal oxide photoelectrodes.

Metal-organic frameworks (MOFs) are promising electrode materials for supercapacitors because of their tunable composition, high porosity, and abundant redox-active sites. However, their practical use is still limited by low intrinsic conductivity, slow ion transport, and limited structural stability during long cycling. In this review, we propose a multiscale framework that shows how to improve ion and electron transport together across different length scales. At the atomic and nanoscale levels, the electronic structure and pore environment are adjusted through metal-node selection, ligand design, and pore tuning to improve conductivity and lower ion-diffusion barriers. At the mesoscale, we build composites and engineer interfaces. This creates continuous electron pathways without blocking ion channels. At the device level, binder-free electrodes, asymmetric configurations, and solid-state electrolytes are highlighted as practical ways to widen the voltage window and improve mechanical stability. Finally, we discuss future opportunities in theory-guided design, operando characterization, and data-driven materials discovery for accelerating the development of MOF-based supercapacitors.

In this study, a facile CO2 etching method is employed to modify microcrystalline graphite (MG), successfully introducing abundant structural defects and pores, increasing the surface area to 58.54 m2 g-1, approximately five times that of pristine MG. This material (MG-CO2-4h) exhibits excellent rate capability: it delivers an initial discharge capacity of 630.72 mAh g-1 with an initial Coulombic efficiency (ICE) of 79.78%, and a discharge specific capacity of 258.9 mAh g-1 at 1 A g-1, representing a 3.1-fold enhancement compared to pristine MG. Moreover, the electrode delivers a stable capacity of 550.08 mAh g-1 over 400 cycles with a Coulombic efficiency (CE) of 99.43% at 0.1 A g-1; even at 1 A g-1, it retains 264.8 mAh g-1 after 1500 cycles with 99.54% CE. These results highlight the material's superior rate capability and cycling stability. This work provides a straightforward and effective modification method, demonstrating that the CO2-etched microcrystalline graphite holds promising potential as an advanced lithium-ion battery (LIB) anode material.

Bismuth vanadate (BiVO₄) has emerged as a promising photoanode material for photoelectrochemical (PEC) water splitting due to its suitable band gap and excellent chemical stability. However, its practical application is often constrained by inefficient charge separation and sluggish surface reaction kinetics. In this work, we report a systematic investigation into the precursor concentration-regulated synthesis of porous BiVO₄ thin-film photoanodes using a modified sequential ionic layer adsorption and reaction (SILAR) method combined with a BiOI template. By precisely controlling the precursor concentration from 2.0 mM to 9.5 mM, we establish a clear structure–property–performance correlation. The optimized photoanode obtained at a precursor concentration of 6.5 mM exhibits a highly interconnected porous network composed of ultrafine grains, which significantly enlarges the electrochemically active surface area and enhances charge carrier dynamics. Remarkably, this undoped, cocatalyst-free BiVO₄ photoanode achieves a benchmark photocurrent density of 2.41 mA cm⁻² at 1.23 V vs. RHE under AM 1.5G illumination, representing a 2.5-fold enhancement over the control sample. Comprehensive photoelectrochemical analyses reveal that this superior performance originates from synergistic improvements in charge carrier dynamics: a 62% reduction in charge transfer resistance, a 2.5-fold prolonged carrier lifetime (20.04 ms), and a negatively shifted flat-band potential. This work establishes a clear structure–property–performance relationship for BiVO₄ thin-film photoanodes fabricated via the SILAR-BiOI template route, offering a simple, scalable, and cost-effective strategy for the controlled synthesis of high-performance metal oxide photoelectrodes.

Layered double hydroxides (LDHs) are promising supercapacitor electrode materials but suffer from poor conductivity and inadequate cycling stability. To address these issues, we report a room-temperature impregnation strategy to coat conductive Ti₃C₂Tₓ MXene nanosheets onto NiCoAl LDH, forming a three-dimensional network composite. The optimal MXene loading (16 wt%) yields a well-defined interconnected architecture, delivering a specific capacitance of 1742 F g⁻¹ at 1 A g⁻¹ and retaining 82.1% of its initial capacitance after 5000 cycles at 10 A g⁻¹. An asymmetric supercapacitor (ASC) assembled with this material achieves an energy density of 31.5 Wh kg⁻¹ at 750 W kg⁻¹ with 83.3% capacitance retention after 5000 cycles. These results demonstrate the potential of the NiCoAl LDH/MXene composite for high-performance supercapacitors.

All-solid-state lithium batteries have attracted considerable attention for next-generation energy storage, yet their practical development remains limited by the complex trade-off among ionic conductivity, electrochemical stability, and interfacial compatibility of solid electrolytes. Recently, high-entropy strategies have provided new opportunities for regulating the structural complexity of solid electrolytes. However, the role of entropy in determining Li+ transport and interfacial stability remains insufficiently understood. This review summarizes recent advances in high-entropy solid-state electrolytes, with emphasis on the relationship between configurational entropy, local structural regulation, ionic transport, and electrochemical stability. The fundamental concepts and criteria for high-entropy design are first discussed, followed by an overview of representative oxide, sulfide, halide, and polymer/composite electrolyte systems. Particular attention is given to how high-entropy-induced structural complexity influences Li+ migration pathways, defect structures, and interfacial behavior, while distinguishing entropy-related effects from conventional multicomponent modification. Finally, emerging computational and machine-learning approaches are discussed to highlight future directions for rational high-entropy electrolyte design.

With the increasing demand for energy conservation and environmental protection, supercapacitors have attracted considerable attention due to their superior advantages. In this study, the Co3O4@NiCo2S4 heterostructure composite materials have been synthesized by combining hydrothermal and electrodeposition techniques. The unique core-shell heterostructures significantly enhanced the electron migration rate and electrolyte ion diffusion. The prepared magnolia-like Co3O4 exhibited specific capacitance of 850 F g-1 at discharge current density of 0.5 A g-1 and capacitance retention of 89.3% after 10,000 continuous cycles at 1 A g-1, possessing favorable cycling stability. The Co3O4@NiCo2S4 composites presented excellent electrochemical performance, exhibiting a high specific capacitance (1552 F g-1 at 0.5 A g-1 and 1093 F g-1 at 20 A g-1) and remarkable cycle stability (92.6% retention after 10,000 cycles and 84.4% after 20,000 cycles). In addition, the Co3O4@NiCo2S4//activated carbon asymmetric supercapacitor (Co3O4@NiCo2S4//AC ASC) device was fabricated. The specific capacitance retention of 87.6% was obtained after 20,000 continuous cycles at 1 A g-1. Furthermore, the maximum energy density and power density reached 65.3 Wh kg-1 and 16,000 W kg-1, respectively. These findings indicated the developed Co3O4@NiCo2S4 composites have significant potential application in energy storage fields.

The development of high-performance electrode materials is crucial for advancing supercapacitor technology, which is limited by the trade-off between energy density and power density. Metal-organic frameworks (MOFs) show great promise, but their practical application is often hindered by poor electrical conductivity and complex synthesis routes. This work presents a facile one-step electrodeposition strategy for the direct growth of manganese-doped nickel-metal organic frameworks (NiMn-MOFs) on nickel foam. The effects of key synthesis parameters, including the Ni/Mn molar ratio and deposition potential, on the material's morphology, structure, and electrochemical performance were systematically investigated. Comprehensive characterization confirmed the successful formation of NiMn-MOFs with a tunable structure and the presence of Ni-O-Mn bridging bonds, which induce favorable electronic synergy. The optimized electrode (NiMn-MOF-2 with a Ni/Mn ratio of 5: 2) exhibited an outstanding specific capacitance of 1590 F g-1 at 3 A g-1 and good rate capability, retaining 1250 F g-1 (78.6% retention, equivalent to a 21.4% decay) at 10 A g-1 and 850 F g-1 (53.5% retention) at 30 A g-1. Furthermore, an asymmetric supercapacitor assembled with NiMn-MOF-2 as the positive electrode and activated carbon as the negative electrode achieved a high energy density of 68.3 Wh kg-1 at a power density of 2100 W kg-1, along with excellent cycling stability (96% capacitance retention after 10,000 cycles). This study demonstrates that one-step electrodeposition is an efficient method for fabricating high-performance bimetallic MOF electrodes for next-generation energy storage devices.

With the increasing demand for energy conservation and environmental protection, supercapacitors have attracted considerable attention due to their superior advantages. In this study, the Co3O4@NiCo2S4 heterostructure composite materials have been synthesized by combining hydrothermal and electrodeposition techniques. The unique core–shell heterostructures significantly enhanced the electron migration rate and electrolyte ion diffusion. The prepared magnolia-like Co3O4 exhibited specific capacitance of 850 F g−1 at discharge current density of 0.5 A g−1 and capacitance retention of 89.3

Although bismuth vanadate (BiVO4) holds great promise as a photoanode material for photoelectrochemical (PEC) water splitting, its performance is constrained by inefficient charge separation and sluggish surface reaction kinetics. Herein, we report a facile modified successive ionic layer adsorption and reaction (SILAR) approach to construct BiVO4 photoanodes. This approach involves the deposition of BiOI precursor templates on FTO substrates, followed by conversion to porous monoclinic BiVO4. By systematically adjusting the SILAR precursor concentration from 2 to 9.5 mM, we reveal its critical role in determining the grain size and porous network interconnectivity of the resulting BiVO4 films. At the optimal concentration of 6.5 mM, the BiVO4 photoanode delivers a benchmark photocurrent density of 2.41 mA cm−2 at 1.23 V vs. RHE under AM 1.5 G illumination. This value represents a state-of-the-art performance for undoped, cocatalyst-free BiVO4 photoanodes prepared by the SILAR method. Comprehensive PEC analyses reveal that this benchmark performance originates from a synergistic combination of enhanced carrier dynamics: an increased carrier density, a substantially reduced charge transfer resistance (by 62%), and a prolonged carrier lifetime (a 2.5-fold increase). These improvements are attributed to the formation of a highly interconnected porous framework composed of ultrafine grains, which provides a significantly enlarged electrochemically active surface area. This work presents a straightforward and scalable strategy for fabricating high-performance BiVO4 photoanodes through precise parameter control in the SILAR process, offering valuable insights for the controlled synthesis of other metal oxide photoelectrodes.

Petroleum asphalt, due to its low cost and high carbon content, is a promising precursor of high-value carbon materials. However, electrospinning-based fabrication requires complex pretreatment and substantial amounts of additives like polyacrylonitrile (PAN), polyvinyl pyrrolidone (PVP), or polystyrene (PS), which limit asphalt utilization. Furthermore, comparative studies on different types of supported asphalt-based carbon fibers remain limited. Here, N,N-dimethylacetamide (DMA) was employed as a solvent to achieve a mass ratio of asphalt to PAN of 2 : 1, facilitating the preparation of asphalt-based carbon fibers loaded with various metal salts, including metalloporphyrin salts, nitrates, and metal oxides. Comparative analysis indicated that small amounts of nitrates promoted the formation of well-defined fiber morphologies, whereas oxides interacted with asphalt to create unique bead-on-string structures. Additionally, the presence of oxides delayed the release of gaseous products during carbonization, resulting in carbon fibers with finer diameters. Electrochemical evaluations demonstrated that the bead-on-string structures exhibited notable advantages in oxygen evolution reaction (OER) activity. These findings offer valuable insights into the design of carbon fibers with high asphalt content for advanced applications.

Layered double hydroxide (LDH) holds a prospective position in the realm of electrode materials for super-capacitors, due to its distinctive layered structure. However, its inherent low conductivity hinders its possible utilization in supercapacitors. In this study, we synthesized CoFe-LDH nanosheets and introduced multi-walled carbon nanotubes (MWCNTs) to construct MWCNTs wrapped CoFe-LDH nanocomposites. The results show that the CoFe-LDH/MWCNTs nanocomposite has a specific capacitance of 752.5 F/g under a current density of 1 A/g. The potential electrochemical capability of the CoFe-LDH/MWCNTs nanocomposite is excited via the construction of the conductive network of MWCNTs. High energy density (71 Wh/kg) and power density (9800 W/ kg) are generated in an asymmetric supercapacitor with CoFe-LDH/MWCNTs nanocomposite as electrochemical active material, showing excellent cycle stability of 88.9 % capacitance remaining even after 10,000 cycles. These results indicate that MWCNTs wrapped CoFe-LDH composites are promising candidates for high performance supercapacitors.

A three-dimensional (3D) TiO2@Bi2MoO6 heterojunction array was successfully fabricated through the in situ growth of aligned Bi2MoO6 nanosheets (NSs) on highly ordered TiO2 nanorod (NR) arrays. The synthesized type-II band-aligned heterostructure exhibits extended light absorption, a significantly enlarged active surface area, and remarkably improved charge separation efficiency, leading to exceptional photoelectrochemical (PEC) performance. The optimized TiO2@Bi2MoO6 (TiO2-0.8Bi) photoanode achieves an outstanding photocurrent density of 3.7 mA cm-2 at 1.23 V vs. RHE, representing a 4.6-fold enhancement compared to pristine TiO2. Furthermore, the heterostructure demonstrates a maximum incident photon-to-current conversion efficiency (IPCE) of 71.4 +/- 0.7% at similar to 380 nm, which is approximately 2.5 times higher than that of pure-phase TiO2 NR arrays (31.2%). These superior PEC properties are attributed to the synergistic effects of enhanced light harvesting, efficient interfacial charge transfer, and suppressed carrier recombination. This work provides a promising strategy for designing high-performance heterojunction-based photoanodes for solar energy conversion applications.

Against a global imbalance between limited metal resources and growing demand, recovering valuable metals efficiently from spent lithium-ion batteries (LIBs) is crucial to promoting sustainable development. However, existing recycling methods typically suffer from excessive energy demand and significant carbon emissions, impeding the advancement of green recycling technologies. This study proposes a mechanochemical activation-assisted hydrogen reduction strategy (MCA-CLCH) based on chemical looping principles, aiming to achieve efficient and low-carbon recovery of lithium (Li) and cobalt (Co) from spent LiCoO2 (LCO) cathode materials. This method leverages chemical looping principles by using LCO as the oxygen carrier and combines mechanochemical activation-induced structural modulation to promote efficient reduction of the oxygen carrier under a hydrogen atmosphere. A series of microscopic experiments confirmed that MCA induces particle refinement, lattice distortion, and oxygen vacancy generation, thus modulating the material's microstructure and providing essential active sites for hydrogen reduction. Experimental results show that compared with the single CLCH recovery method, the MCA-CLCH strategy enables a reduction in temperature from 800 degrees C to 600 degrees C or a decrease in reaction time from 120 to 90 min. Kinetic calculations reveal that MCA reduces the average activation energy of the hydrogen thermal reduction of LCO by 26.24 kJ/mol, confirming its promoting effect on reaction kinetics. Furthermore, Process analysis indicates 22.94 % lower energy consumption, 4.83 kg CO2 per kg LCO (about 84 % below a pyrometallurgical route), and a net profit of 69.5$ per kg LCO, highlighting the green and economical potential of MCA-CLCH.

In this study, the three-dimensional (3D) architectures of Co3O4@Ni(OH)2 core-shell heterostructures (CSHs) were engineered on nickel foam (NF) via a facile two-step hydrothermal route. The integrated structure of the resulting material enables its use as a binder-free supercapacitor electrode with significantly improved electrochemical properties. It achieves a superior specific capacitance (Cs) of 2332.5 F g-1 at 1 A g-1 and 2350 F g-1 at 2 A g-1 within a potential window of 0-0.40 V (vs. SCE), along with exceptional cycling durability evidenced by 82.4 % capacity retention over 10000 cycles. The assembled Co3O4@Ni(OH)2 CSHs/NF//CNTs asymmetric supercapacitor (ASC) exhibits a high energy density of 65.8 Wh kg-1 (1600 W kg-1) and exceptional long-term stability, retaining 82.5 % of its initial capacitance with nearly 100 % coulombic efficiency after 10000 cycles. The exceptional performance arises from a unique 3D hierarchical architecture that ensures high conductivity, offers abundant active sites, and fosters a synergistic effect between the wire-like Co3O4 core and the ultrathin Ni(OH)2 shell. This work opens a new avenue for the rational design of high-performance electrode materials for advanced energy storage systems.

Metal-organic frameworks (MOFs) with redox-active metal ions and a variety of organic linkers have been widely investigated as prospective electrode materials for supercapacitors. Here, we generate uniformly dense spherical particles on a nickel foam substrate by a simple and binder-free one-step electrodeposition method by adjusting the deposition conditions. The active cobalt in the Co-MOF thin films can provide a large number of redox sites for the electrochemical reaction, while the uniform binder-free Co-MOF structure can keep enough contact area with the electrolyte to reduce the ion transport resistance. As-prepared CTB-0.9 (Co-MOF with a deposition voltage of − 0.9 V) thin film has a specific capacitance of 797.5 F g−1 at a current density of 1 A g−1, exhibiting excellent electrochemical properties. An asymmetric supercapacitor with CTB-0.9 as the positive material and activated carbon as the negative material also demonstrates competitive electrochemical performances, which has a high energy density of 34.3 Wh Kg−1 at a power density of 36,317.6 W Kg−1. This work may open up an effective approach to realize the electrosynthesis of Co-MOF films, promoting the utilization of Co-based MOFs in energy storage and conversion fields.

H 2 V 3 O 8 has been regarded as a compelling cathode material for aqueous zinc-ion batteries (AZIBs) owing to its elevated theoretical capacity, abundance of vanadium valence states, and advantageous layered configuration. Nonetheless, the intrinsically low conductivity and sluggish ionic reaction kinetics of H 2 V 3 O 8 result in undesirable, constraining its broader implementation in AZIBs. In this study, a facile hydrothermal approach was utilized to prepare H 2 V 3 O 8 nanowires with an abundance of oxygen vacancies. The combination of nanowire nanostructure and oxygen vacancies of the H 2 V 3 O 8 offer improved ion diffusion kinetics and enhanced electronic conductivity, leading to a superior improved electrochemical performance. Particularly, the H 2 V 3 O 8 nanowire cathodes with the optimal oxygen vacancy concentration (HVO-20) exhibit a specific capacity of 461.7 mAh g − 1 at 0.3 A g − 1 and exceptional cycle life of 198.8 mAh g − 1 after 1000 cycles at 1.0 A g − 1 . The investigation unveils the impact of oxygen vacancy vanadium-based oxides on the performance of AZIBs, presenting a viable strategy for advanced cathode materials in AZIBs.

In order to improve the performance of the compressed air energy storage (CAES) system, a novel design is proposed: the CAES system is combined with the municipal solid waste power generation systems, including a waste incineration power generation system and a biogas power generation system. During the charging process, the feedwater and the condensate from the waste incineration power generation system are used to cool the compressed air. During the discharge process, the released compressed air is heated by the flue gas from the waste incineration power generation system, and the high-temperature compressed air works in the expander. Finally, the expanded air from the expander is fed into the combustor of the biogas power generation system, thus replacing the compressor of the gas cycle. Through the system integration, the efficiency of the CAES system is improved, and some equipment of the original CAES system is reduced. Based on the systems simulation, energy analysis, exergy analysis, economic analysis, and sensitivity analysis are performed. As a result, for the CAES subsystem, the round-trip efficiency, the energy storage density, and the exergy efficiency can reach 75.32%, 14.10 MJ/m3, and 74.31%. Besides, the dynamic payback period can reach 6.82 years.