Lithium batteries represent a highly promising energy storage technology and have attracted significant attention due to their high energy density. Porous carbon materials have gained extensive interest as critical electrode materials in advanced lithium-based batteries. However, when applied to battery cathodes and anodes, the core challenges requiring resolution for porous carbon and the corresponding design strategies exhibit fundamental differences. This paper systematically reviews porous carbon preparation techniques, including soft/hard template methods, self-templating approaches, activation methods, and heteroatom doping modification strategies. It emphasizes customized design principles tailored to the distinct functional requirements of anodes and cathodes. For anode materials, porous carbon primarily serves as a mechanical buffer and conductive matrix. Its design centers on constructing a hierarchical pore structure with high porosity and toughness to accommodate significant volume expansion. For cathode materials, porous carbon must evolve to integrate physical confinement, chemical adsorption, and catalytic conversion functions. Performance enhancement critically depends on the future development trajectory of the material in high-performance lithium batteries, aiming to provide rational design guidance for carbon materials tailored to specific applications.

Most of the traditional synthesis of lithium titanate is to synthesize lithium titanate first and then coat it with carbon. This study constructs a one-step hydrothermal in-situ construction of a three-dimensional carbon scaffold structure with internal and external connectivity, wherein submicron flower-like Li4Ti5O12 is encapsulated within it. The hierarchical micro flower morphology shortens Li+ diffusion pathways, while the carbon encapsulation establishes continuous grain-boundary electron transport channels, synergistically accelerating charge transfer kinetics. The carbon network also serves as a robust structural buffer against particle pulverization and electrolyte corrosion under high-rate cycling. The optimized electrode delivers a reversible capacity of 129 mAh g−1 at 10C with 96.14% retention after 1000 cycles, and maintains 96.28% retention at 20C over 1000 cycles. Structural and electronic state analyses reveal that the accelerated kinetics and reinforced structural integrity stem from the hierarchical carbon-encapsulated micro flower structure, providing a mechanistic foundation for designing long-life, high-rate lithium titanate anodes.

Given the widespread application and subsequent short lifespan of lithium-ion batteries (LIBs), the development of effective recycling technologies for spent batteries is critical. This study proposes a closed-loop recovery process for spent lithium iron phosphate (LiFePO4) batteries using a low-temperature chlorination leaching and co-precipitation method. A selective oxidative leaching process, employing a ferric chloride-hydrochloric acid (FeCl3-HCl) solution, was utilized to extract valuable metals from the cathode material. Mechanistically, Fe3+ in the leachant serves as an oxidant that oxidizes Fe2+ within the LiFePO4 olivine structure to Fe3+, triggering the topotactic conversion of LiFePO4 to FePO4 while simultaneously releasing Li+ into the solution. Thermodynamic calculations indicated an optimal leaching temperature range of 40–90 °C. The optimal conditions for selective lithium leaching are a temperature of 70 °C, a duration of 80 min, a liquid-to-solid ratio of 100 mL/g, an HCl concentration of 3 mol/L and a FeCl3 concentration of 30 g/L. The Li leaching efficiency exceeds 95%, while the Fe leaching efficiency is controlled at approximately 3%. Kinetic analysis revealed that the lithium leaching process was controlled by an interfacial chemical reaction. Subsequently, LiFePO4/C material was successfully regenerated from the purified leachate. Single-factor calcination experiments established the optimal regeneration conditions as a temperature of 700 °C, a duration of 15 h, a lithium mixing ratio of 1.01, and a pure nitrogen atmosphere. The regenerated material exhibited excellent electrochemical performance, with an initial discharge specific capacity of 166.2 mAh·g−1 at 0.1C and a capacity retention of 86.2% after 100 cycles at 1C. The regenerated material displayed a well-defined crystal structure and enhanced electrochemical properties, providing a significant reference for the sustainable recycling and reuse of spent lithium-ion batteries.

With the evolution of energy storage battery technology, potassium-ion batteries (PIBs) have emerged as an effective alternative to lithium-ion batteries (LIBs), leveraging natural potassium abundance and cost advantages. Carbon materials represent the most promising anodes candidates for PIBs, among which biomass-derived carbon anode materials have garnered significant research interest due to their environmental sustainability, resource availability, low synthesis costs, and inherent structural benefits. This review comprehensively examines recent progress in the synthesis of biomass-derived carbon and their application as anode for PIBs. Primary focus is given to biomass precursors, morphological and structural characteristics, and synthesis methodologies. Strategies for enhancing potassium storage performance through material modification are systematically evaluated, and the underlying potassium storage mechanisms of biomass-derived carbon anodes are elucidated. Finally, the challenges and strategies for potassium storage in biomass-derived carbon anodes are emphasized. This work provides fundamental insights and design principles for developing high-performance biomass-derived carbon anodes for PIBs.

Sodium-ion battery O3-type layered oxides typically experience sluggish kinetics and detrimental phase transitions at deep desodiation states (i.e., >4.0 V), resulting in poor rate performance and severe capacity degradation. To tackle these handicaps, we leveraged the high-entropy strategy and regulated the Na+ ion content to create a specific number of Na vacancies and optimized their concentration. The results indicate that reducing the Na content to form Na vacancies can enhance Na+ diffusion kinetics and structural stability, thereby improving the rate performance and cycling stability. Meanwhile, the introduction of Na vacancies increases the valence states of various transition metals, thereby enhancing the antioxidative capability of the material. Notably, the O3-type Na0.8 cathode exhibits a discharge capacity of 137.8 mAh g-1 at 0.1 C, much higher than that of the Na1 cathode (124.5 mAh g-1). Additionally, the Na0.8 cathode delivers an initial discharge capacity of 110.9 mAh g-1 at 0.5 C and retains 82% of its capacity after 200 cycles. In situ diffraction analysis demonstrated that the formation of Na vacancies significantly suppresses the phase transition from O3 to P3 during desodiation and sodiation processes. These results suggest that Na-deficient O3-type cathodes are promising candidates for large-scale applications in sodium-ion batteries.

Molybdenum diselenide (MoSe2), a transition metal diselenide, exhibits substantial pseudocapacitive behavior but suffers from intrinsically low electrical conductivity. This limitation impedes rapid electron transport within electrodes, particularly during high-rate charge/discharge cycles. To address this challenge, we engineered MoSe2/C composites by integrating conductive carbon matrices that serve as efficient “electron highways,” significantly enhancing overall electrical conductivity. The composites were synthesized via a one-step hydrothermal method using glucose as the carbon source directly introduced into the MoSe2 precursor system. Structural and morphological characterizations (SEM, XRD, and XPS) confirmed the successful formation of lamellar MoSe2/C nanocomposites. Electrochemical evaluation revealed the special performance of the supercapacitor. At 1 A g−1, the specific capacitance of the optimized composite electrode was 235.85 F g−1, which was 69.4

Metal‑nitrogen-carbon (M-N-C) materials originating from prussian blue analogs (PBAs) are regarded as attractive catalysts toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Nevertheless, they suffer from drawbacks of poor conductivity and catalyst deactivation owing to metal aggregation. In this work, through a dual optimization strategy depending on structure regulation and interface engineering, we prepared a bead-like iron diselenide/nickel diselenide‑nitrogen-doped carbon@carbon nanofibers (FeSe2/NiSe2-NC@CNF) electrocatalyst with FeSe2/NiSe2-NC evenly anchored in the carbon nanofibers (CNF) one by one. FeSe2/NiSe2-NC@CNF demonstrates outstanding dual-functional electrocatalytic activity toward OER (Ej=10 = 254 mV, Ej=300 = 403 mV) and HER (Ej=450 = 601 mV) at high current densities. In addition, when applied to overall water splitting, the potential of FeSe2/NiSe2-NC@CNF at 10 mA·cm-2 is only 1.63 V, indicating its outstanding water electrolysis capability. X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations indicate that the additional unsaturated coordinated NiSe bonds in FeSe2/NiSe2-NC@CNF are beneficial to optimizing the adsorption/desorption behaviors of intermediates and accelerating the rate-determining step (*O transforming into *OOH). The present study proposes a rational design strategy to optimize the performance of M-N-C catalysts, and lays the foundation for the advancement of superior bifunctional non-noble metal catalysts toward overall water electrolysis.

This article focuses on the preparation of multifaceted metal sulfides through the design of a rational experimental scheme. By employing component modulation strategies and nanostructure design, the cyclic stability can be enhanced, and the volume expansion of polymetallic sulphides is effectively controlled. Nano-spherical Co8NiS8/ZnS/Cu1.8S is prepared under the optimized experimental conditions, and the results demonstrate that the strategies of nanoengineering design and providing a large volume space to relieve mechanical stresses improve both the sodium storage performance and electrochemical kinetic properties of the mixed-metal sulfides. When Co8NiS8/ZnS/Cu1.8S is used as the working electrode to assemble sodium-ion half-cells, the half-cells exhibit excellent electrochemical performance: a capacity of 498.2 mAh g− 1 at a current density of 1.0 A g− 1, and a capacity retention of 72.1

Hot rolling production scheduling (HRPS) is an essential process in modern steel manufacturing. Its effectiveness is influenced by three primary challenges: selecting suitable slabs to maximize efficiency and maintain product quality, adhering to increasingly stringent carbon tax regulations, and managing uncertainties in processing times stemming from fluctuations in rolling speed. This article presents a novel robust HRPS problem under carbon tax regulation (RHRPSP-CTR) that considers slab selection, carbon tax regulation, and uncertain processing times simultaneously for the first time. Based on a budgeted uncertainty set, we develop a robust counterpart model that utilizes a classical dualization scheme and dynamic programming recursive equations to address the challenges associated with evaluating the worst case cost of carbon emissions (CEs) and determining the worst case completion time for each slab caused by processing time uncertainty, respectively. Recognizing the characteristics of slab selection and the high computational complexity in the large-scale RHRPSP-CTR, we propose an adaptive large neighborhood search algorithm incorporating two enhancement strategies: a slab selection rule and a max-min weight update mechanism. Extensive computational experiments demonstrate that the proposed method yields optimal solutions for small-scale problem instances and high-quality, robust solutions for large-scale instances within a relatively short computation time. Moreover, the results indicate that compared with deterministic HRPS schemes, robust HRPS schemes lead to only a slight increase in cost. Notably, a higher carbon tax does not necessarily lead to lower CEs, and a larger uncertainty budget coefficient or uncertainty range does not always result in higher CEs.

This article focuses on the preparation of multifaceted metal sulfides through the design of a rational experimental scheme. By employing component modulation strategies and nanostructure design, the cyclic stability can be enhanced, and the volume expansion of polymetallic sulphides is effectively controlled. Nano-spherical Co8NiS8/ZnS/Cu1.8S is prepared under the optimized experimental conditions, and the results demonstrate that the strategies of nanoengineering design and providing a large volume space to relieve mechanical stresses improve both the sodium storage performance and electrochemical kinetic properties of the mixed-metal sulfides. When Co8NiS8/ZnS/Cu1.8S is used as the working electrode to assemble sodium-ion half-cells, the half-cells exhibit excellent electrochemical performance: a capacity of 498.2 mAh g- 1 at a current density of 1.0 A g- 1, and a capacity retention of 72.1% after 500 cycles at a high current of 2.0 A g- 1.This work presents a novel anode material for sodium-ion batteries with considerable potential.

Nickel‑cobalt layered double hydroxides (NiCo-LDHs) have attracted considerable attention as promising battery-type electrode materials for supercapacitors because of their abundant redox reaction, high theoretical capacitance. Despite significant progress in the synthesis, structural design, and electrochemical applications of NiCo-LDHs, their practical performance is still hindered by several intrinsic limitations. Moreover, underlying degradation mechanisms remain insufficiently understood. This review comprehensively summarizes the recent advances in NiCo-LDHs electrode materials for supercapacitor applications. The major challenges limiting the electrochemical performance of NiCo-LDHs are analyzed, including phase instability, oxygen/hydrogen evolution side reactions, poor electrical conductivity, Jahn-Teller distortion, and low active-site utilization. Subsequently, various optimization strategies are systematically reviewed from a challenge-oriented perspective. Ion doping, which can induce oxygen vacancies and regulate the local electronic environment, is highlighted as an effective strategy for increasing active-site utilization and suppressing irreversible phase transitions. Advanced electrolyte strategies, particularly Deep eutectic solvents, are emphasized for suppressing oxygen/hydrogen evolution reactions and widening the electrochemical stability window. PN heterostructures and conductive composite networks effectively address the intrinsically low electrical conductivity of NiCo-LDHs by enhancing electron/ion transport and charge-transfer kinetics. Core-shell architectures mitigate volume expansion, preserve structural integrity, and improve long-term cycling stability. High-entropy engineering is further discussed as a promising approach for simultaneously enhancing structural stability and electrochemical activity through entropy stabilization and polymetallic synergistic effects. Finally, the current challenges and future research directions of NiCo-LDHs electrode materials are analyzed, providing insights into rational design strategies and promoting their practical application in advanced aqueous supercapacitors.

The inevitable graphitization of bituminous coal during pyrolysis inhibits its application as a precursor for carbon anodes in sodium ion batteries. Heterogeneous crosslinking modification is an effective pathway to enhance its degree of disorder. In this paper, carbon dots (CDs) were employed as a regulator to modulate the structure of bituminous coal-based carbon. The C(O)-O groups formed through cross-linking reactions between oxygencontaining groups of CDs and bituminous coal suppress the long-range ordered arrangement of carbon microcrystals during coal pyrolysis, thereby enhancing the disorder of coal-based carbon. The test results reveal that the obtained BCDs-75 possesses expanded interlayer spacing, abundant closed pores and surface defects. As an anode for SIBs, BCDs-75 releases an exceptional initial charge capacity of 302 mAh g- 1 at 0.1 A g- 1, with an initial coulombic efficiency of 65.5%. The combined electrochemical measurement and carbon structure characterization indicate that the disordered structure and closed pores increase the plateau capacity of BCDs-75 anode, while the increase of surface oxygen-containing groups enhance its slope capacity.

Fe2O3 has aroused wide attention due to its high theoretical specific capacity with cost-effectiveness. However, the violent volume fluctuation and undesirable reaction kinetics during charge-discharge cycling cause significant structural deformation and capacity decay, thereby hindering its practical applications. In this study, we report a simple one-step thermal treatment to synthesize Fe2O3 nanoparticles with an ant-nest-like three‑dimensional (3D) porous nanostructure (AP‑Fe2O3). The self-assembled porous structure with void space leads to the enhancement of mechanical stability, which alleviates severe volume expansion issues during cycling. Furthermore, the 3D bicontinuous nanopores with high specific surface area provide rich electrochemical active sites and shorten the transport pathways of Li+ ions and electrons, reinforcing the electrochemical reversibility and reaction kinetics. As a result, AP‑Fe2O3 exhibits a high reversible specific capacity (1140 mAh g-1 after 90 cycles) and excellent rate capability. The simple 3D porous nanostructure design strategy developed in this work enables the fabrication of high‑performance metal oxide anodes as well as other high‑capacity anode materials for energy storage applications.

The rapid advancement of flexible and wearable electronics demands energy storage systems that are flexible, high-power, and durable. Flexible supercapacitors (FSCs) have emerged as promising candidates due to their high-power density, excellent cycling stability, and mechanical flexibility. This review systematically summarizes recent progress, challenges, and future perspectives in FSCs. We first elucidate the charge storage mechanisms of electric double-layer capacitors, pseudocapacitors, and hybrid systems. We then explore electrode architectures across one-dimensional fibers, two-dimensional films, and three-dimensional porous scaffolds. Key electrode materials — carbon materials, conductive polymers, transition metal compounds, and MOFs — are analyzed, along with gel polymer electrolytes. The device manufacturing process from electrode preparation to final assembly is briefly outlined, and the dominant failure mechanisms under mechanical deformation are discussed with corresponding mitigation strategies. Modification strategies from material selection and structural design are also presented. Finally, we outline major commercialization barriers and future research directions. This review aims to provide insights for developing high-performance, durable, and integrable flexible energy storage for wearable electronics.

MXene-based electrode materials for supercapacitors are hindered in large-scale applications by inherent drawbacks such as severe restacking, susceptibility to oxidation, and limited energy density. To overcome these limitations, a multi-component synergistic design strategy is proposed. In this work, nickel phthalocyanine (NiPc) molecular complexes are anchored onto MoS2 wrapped on MXene sheets, constructing a three-dimensional (3D) hierarchical heterostructure electrode material denoted as NiPc@MoS2/Ti3C2Tx. MXene acts as a conductive framework, providing efficient electron transport pathways. The intercalation of MoS2 effectively suppresses MXene restacking while introducing abundant electrochemically active sites. Meanwhile, NiPc complexes function as molecular pillars to expand the interlayer spacing, donate electrons to induce a partial phase transition of MoS2 (from 2H to 1T phase), and provide reversible redox-active centers. Density functional theory (DFT) calculations confirm that the introduction of NiPc thermodynamically and electronically facilitates the phase transition from 2H to 1T in MoS2. Consequently, the composite exhibits a substantial specific capacitance of 351.4 F g−1 at a current density of 0.5 A g−1, while maintaining approximately 82.1% of its capacitance at 10 A g−1, thereby demonstrating exceptional rate capability. An asymmetric supercapacitor assembled with this material exhibits an energy density of 33.89 Wh kg−1 at a power density of 800 W kg−1 and maintains 88% capacity after 10,000 cycles. These results demonstrate the strong potential of NiPc@MoS2/Ti3C2Tx for next-generation supercapacitors.

To address the bottlenecks of insufficient catalytic activity, low target product selectivity, and ambiguous interfacial reaction mechanism of non-precious metal catalysts for the electrocatalytic glycerol oxidation reaction (GOR), we controllably fabricated a series of three-dimensional nanoflower-like Vs-NiCo2S4-x electrocatalysts with tunable sulfur vacancy contents via a solvothermal method coupled with a NaBH4 liquid-phase reduction strategy. Structural characterizations confirm that the moderate introduction of sulfur vacancies effectively modulates the surface electronic structure and increases the number of undercoordinated active sites, while preserving the main spinel crystal phase and 3D nanoflower morphology of NiCo2S4. Electrochemical measurements show that the optimal sample Vs-NiCo2S4-0.15 achieves a current density of 155 mA·cm-2 at 1.7 V (vs. RHE) with a formate selectivity of 67.4%, and maintains stable operation for 36 h without obvious performance decay. In-situ Fourier transform infrared spectroscopy tracks the dynamic evolution of multi-carbon oxygenated intermediates, verifying that sulfur vacancies stabilize reaction intermediates, promote the selective cleavage of C–C bonds, and inhibit the deep over-oxidation side reaction of glycerol. This work provides experimental support for constructing high-performance GOR electrocatalysts through defect engineering, and offers in-situ spectroscopic and kinetic insights into the interfacial reaction mechanism.

Voltage hysteresis in layered oxide cathodes of Li/Na-ion batteries, a significant barrier to energy efficiency, is commonly attributed to reversible cation migration. This is particularly prevalent in materials utilizing anionic redox for high capacity, yet the strong coupling between cation migration and complex anionic processes (such as O-O dimerization, oxygen loss, and charge transfer) has obscured a definitive causal link. To decouple these phenomena, we designed a series of P2-type Na2/3Ni0.1M0.1Mn0.8O2 compounds, where M is an electrochemically inactive trivalent cation (Al3+, Ga3+, Sc3+) of increasing ionic radius (0.535 Å, 0.62 Å, 0.745 Å). Interestingly, these systems exhibit negligible anionic redox activity but display increasing voltage hysteresis that scales with the size of the M3+ cations. Through a combination of experimental and theoretical analyses, we correlate this hysteresis with an enhanced tendency for reversible interlayer cation migration of M3+, which is facilitated by a larger cationic size that is more adaptive to the large Na interlayer spacing. By successfully isolating cation migration from anionic redox, this work establishes its direct role in driving voltage hysteresis, providing fundamental insights into the design of cathode materials having less cation migration and reduced voltage hysteresis for Na-ion batteries.

Lithium-rich manganese-based layered oxides (LRMO) are regarded as promising cathode materials for future energy storage applications owing to their exceptional specific capacity. However, their practical application is hindered by unstable anionic redox during cycles, which lead to lattice oxygen loss and transition metal ion migration. Herein, a Li2WO4 surface coating along with bulk W doping the synergistic strategy is proposed and developed to solve these issues for Li1.2Mn0.54Ni0.13Co0.13O2 cathode. This synergistic approach effectively shields reactive oxygen species against degradation by the electrolyte, suppressing interfacial side reactions and associated capacity decay. Theoretical calculations demonstrates that the synergistic strategy regulates both the antibonding (TM-O)* orbitals and O 2p nonbonding states in LRMO. This electronic structure modulation improves charge transfer reversibility and oxygen stability, effectively inhibiting structural degradation and undesirable side reactions. The optimized cathode maintained higher capacity retention of 93.1 % at 1C after 150 cycles in comparison to 74.9 % for the pristine LRMO. This method helps explain how bulk and surface modifications work together to stabilize oxygen redox in LRMO cathodes for lithium-ion batteries.

Bismuth (Bi) is a promising alloy-type anode material for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), yet it suffers from severe volume expansion during cycling. Herein, Bi nanoparticles were encapsulated within N/O dual-doped carbon frameworks (Bi/NOCFs) via a facile sol-gel and pyrolysis strategy. In-situ coordination between N-sites and Bi ions ensured uniform dispersion (similar to 20 nm) and robust interfacial coupling. The optimal Bi/NOCFs-4 composite exhibited rapid charge transfer and structural integrity, delivering superior capacity, rate capability, and cycling endurance in both LIBs and SIBs. Kinetic analyses confirmed dominant capacitive-controlled storage and fast ion diffusion. This work provides a rational design strategy for high-performance Bi-based composite anodes through compositional and interfacial engineering.

Layered double hydroxides (LDHs) are promising electrode materials, but their practical application is restricted by structural instability. Although Mn3+ offers high redox activity, its severe Jahn-Teller distortion destabilizes the LDH framework via internal strain. Herein, we report a progressive in-situ oxidation strategy to stabilize Mn3+ in CoNi-LDH(CNM-x) by first introducing Mn2+ and gradually oxidizing it within the host lattice. Experimental Extended X-ray Absorption Fine Structure (EXAFS) characterizations and Density Functional Theory (DFT) calculations firmly verify that this localized lattice strain effectively shifts the d-band center upwards towards the Fermi level. This electronic structure regulation significantly optimizes the intermediate adsorption energy (e.g., OH*), thereby fundamentally promoting the electrocatalytic kinetics. It is worth noting that the mass loading of the active materials on the nickel foam was controlled at approximately 2 mg cm-2. Consequently, the optimized CNM-2 electrode delivers an exceptionally high specific capacity of 745 C g-1 and maintains remarkable long-term structural stability. Furthermore, it exhibits superior electrocatalytic activity for the urea oxidation reaction (UOR). This work provides a crystallographic and kinetic-driven strategy to stabilize Jahn-Teller-active dopants for multidimensional electrochemistry.