Xin Su

Eliminating Co from ultrahigh‐Ni layered cathodes often exacerbates Li/Ni mixing, impeding Li ⁺ transport, amplifying reaction heterogeneity, and accelerating structural degradation. Most strategies focus on minimizing the overall degree of cation mixing, whereas thermodynamic control of antisite spatial organization remains underexplored. Here, we address this central stability challenge by developing a thermodynamics‐guided defect‐engineering strategy that stabilizes spatially correlated Li/Ni antisite configurations in cobalt‐free ultrahigh‐Ni cathodes. Density functional theory screening of high‐valence dopants reveals that Te ⁶⁺ exhibits the strongest energetic preference for spatially correlated antisite configurations. This prediction guides the synthesis of LiNi _0.948 Al _0.045 Te _0.007 O ₂ containing coherent local antisite‐ordered superlattice domains. These ordered domains persist after prolonged cycling, strengthen interlayer coupling, suppress H2–H3 phase separation and c ‐axis contraction, and preserve low‐barrier Li ⁺ migration pathways. Local Te–O coordination further stabilizes lattice oxygen and mitigates oxygen‐loss‐induced surface reconstruction. Consequently, the cathode delivers 185 mAh g ⁻¹ at 10 C, retains 96.7% of its initial capacity after 200 cycles at 1 C with a 4.4 V cutoff, and retains 92% of its initial capacity after 100 cycles with a 4.6 V cutoff. These findings establish the spatial organization of defects as a critical design variable for mitigating the stability‐transport trade‐off in cobalt‐free ultrahigh‐Ni layered cathodes.

High‐capacity and long‐lifespan anode materials are essential to advance the practical deployment of sodium‐ion batteries (SIBs). Transition metal sulfides are promising anode candidates due to their high theoretical capacity, yet their practical applications are hindered by cycling‐induced volume expansion, inferior conductivity, and sodium polysulfide shuttling. This work constructs a novel composite material by embedding ZnS/SnS ₂ heterojunctions into nitrogen‐doped porous glucose‐derived hard carbon (H‐ZSS/NC‐950P) to solve these drawbacks. Electrochemical tests confirm the optimized material delivers outstanding sodium storage performance. It retains a reversible capacity of 588.1 mAh·g ⁻¹ after 300 cycles at 1.0 A·g ⁻¹ , maintains 395.8 mAh·g ⁻¹ at an ultrahigh current of 50 A·g ⁻¹ , and achieves 68% capacity retention over 6000 cycles at 10 A·g ⁻¹ . Such superior performance stems from synergistic effects of the heterostructure. The ZnS/SnS ₂ heterointerface builds an internal electric field to boost charge transfer. Nitrogen doping promotes surface pseudocapacitance. The porous carbon matrix accelerates ion diffusion, relieves volume strain, and anchors sodium polysulfides. Combined with CV and in situ XRD results, a conversion‐alloying sodium storage mechanism is verified. Full‐cell tests with a Na ₃ V ₂ (PO ₄ ) ₃ cathode further prove its practical feasibility. This research clarifies the storage mechanism of metal sulfide‐carbon heterostructures and offers a reliable strategy for high‐performance SIBs anode development.

Fast‐charging lithium batteries (LBs) are regarded as a key technical aspect for electric vehicles (EVs) and advanced energy storage systems. However, their practical application is still severely hindered due to the slow lithium‐ion transfer, unstable interfaces, severe polarization, and safety issues during high‐rate operation. Among the various strategies developed to address these challenges, electrolyte engineering has emerged as one of the most effective and economically viable approaches. This review first provides a detailed account of the critical processes related to electrolytes that determine the fast‐charging performance of LBs, as well as the current challenges faced by electrolyte design. Then, recent advances in electrolyte design for fast‐charging LBs are summarized from the perspectives of new materials discovery and emerging formulation strategies, which are highlighted with encouraging examples to demonstrate how electrolyte chemistry can be used to improve the fast‐charging performance via reconciling the trade‐offs among fast ion transport, interfacial stability, wide‐temperature adaptability, high‐voltage compatibility, and safety concerns. Finally, the remaining challenges and future opportunities are outlined and discussed. This review aims to provide a comprehensive understanding of fast‐charging processes related to electrolytes and to provide useful guidance for the rational design of next‐generation electrolytes for high energy density and safe LBs.

Raising the upper cutoff voltage is an effective route to high‐energy lithium‐metal batteries (LMBs), but severe interfacial instability at Ni‐rich cathodes and lithium‐metal anodes limits their operation. Conventional additives such as vinylene carbonate (VC), fluoroethylene carbonate (FEC), and lithium bis(oxalato)borate (LiBOB) are usually regarded as sacrificial film‐forming agents, while their role in regulating bulk Li ⁺ solvation remains underexplored. Herein, we develop a ternary‐additive carbonate electrolyte and reveal a “solvation reconstruction‐interphase coupling” mechanism, supported by spectroscopy, simulations, and interphase analyses. VC/FEC/LiBOB synergistically reshapes the Li ⁺ primary solvation sheath and tunes the SSIP/CIP/AGG distribution, shifting the electrolyte from a solvent‐dominated structure toward an anion‐/additive‐involved coordination environment without compromising bulk ion transport. Meanwhile, their preferential decomposition constructs inorganic‐rich CEI/SEI layers with enhanced mechanical robustness and reduced interfacial resistance, thereby suppressing electrolyte oxidation, cathode degradation, and Li dendrite growth. As a result, Li||NCM92 cells deliver >185 mAh g ⁻¹ after 50 cycles at 3.0−4.7 V and 150 mAh g ⁻¹ at 10 C, Li||Li cells operate stably for >1300 h, and Gr||NCM811 pouch cells retain 90% capacity after 100 cycles. This work redefines conventional film‐forming additives as dual‐function solvation/interphase regulators for high‐voltage LMBs.

Lithium manganese iron phosphate (LMFP) is a promising cathode material for lithium‐ion batteries, featuring high theoretical energy density, low cost, and excellent safety. However, the practical application of LMFP cathode material is critically limited by their inherent poor electronic conductivity and structural degradation during cycling. To address these bottlenecks, we reported a rational design of an indium (In)‐doped LMFP material. Comprehensive characterizations confirm the successful incorporation of In ³⁺ into the olivine lattice, which induces a slight lattice expansion while maintaining the particle morphology. Crucially, In doping effectively suppresses the Jahn–Teller distortion and mitigates transition metal dissolution. The optimized LiMn _0.5 Fe _0.49 In _0.01 PO ₄ cathode exhibits superior rate capability (157 mAh/g at 0.1C and 125 mAh/g at 5C) and outstanding cycling stability, with nearly zero capacity decay after 300 cycles at 1C. Electrochemical impedance spectroscopy and post‐cycling analysis reveal that the enhanced performance originates from reduced charge‐transfer resistance, accelerated reaction kinetics due to increased electron delocalization, and effective suppression of structural degradation and interfacial side reactions. This work establishes In doping as a potent strategy for concurrently enhancing the electronic conductivity and structural integrity of LMFP cathodes. The successful demonstration of kilogram‐scale synthesis underscores the industrial viability of this approach, thereby paving the way for developing advanced cathode materials toward high‐power and long‐life energy storage.

O3-type layered oxide materials are generally regarded as the most potential cathode candidates for sodium-ion batteries (SIBs) owing to their exceptional energy density and suitable initial Coulombic efficiency. However, the development of the O3-type cathode materials in practical applications is hindered by their poor cyclic and air stability. Herein, we creatively develop a dual-layer interface modification strategy for the O3 cathode (NaNi_0.45Mn_0.4Cu_0.05Ti_0.1O₂), aimed at decreasing the diffusion barrier of Na⁺ and alleviating structural deterioration during the cycle process. The optimized sample (O3@P2@NAO) exhibits a comprehensive improvement in electrochemical properties, characterized by not only high capacity (150 mAh g^-1 at 0.1C) and superior rate capability (126.6 mAh g^-1 at 5C), but also extended cycling stability (90.5% capacity retention after 120 cycles). In addition, the O3@P2@NAO cathode delivers an excellent capacity retention of 85.5% after air exposure to wet air (40% RH) for 7 days. The physicochemical structure and electrochemical tests indicate that the unique double interface modification layers provide rapid Na⁺ transport channels and slow down the corrosion effects of the electrolyte and air on the cathode surface. This work provides a feasible approach for developing O3-type cathodes with application potential and accelerating advancements toward the commercialization of SIBs.

Hard carbon stands as the most commercially viable anode material for sodium‐ion batteries. Numerous studies confirm that closed nanopore design ensures the competitiveness of hard carbon compared to other anodes. However, the complex multi‐scale microstructure of hard carbon poses challenges to the establishment of sodium storage mechanisms and quantitative relationships within closed nanopores. In this regard, closed nanopore engineering has been comprehensively summarized as a significant research direction in the field of hard carbon. Firstly, the sodium storage behavior of distinct nanopore types is compared. Subsequently, the structure and sodium storage behavior of closed nanopores are revealed through contact/non‐contact techniques. Importantly, closed nanopore construction strategies are summarized based on their origins, which are divided into two categories: in situ formation and open nanopore conversion. Finally, perspectives on emerging frontiers are offered, including 3D pore topology visualization, defect modulation effects, multifield‐coupled synthesis techniques, and the data‐driven research paradigm for hard carbons. By synthesizing these advances and proposing a novel design framework, this review is anticipated to provide valuable insights for the design of high‐performance hard carbon, thereby advancing the practical applications of sodium‐ion batteries.

Li₅FeO₄ is a promising pre-lithiation additive for the positive electrode in lithium-ion batteries, offering the potential to enhance energy density. However, its susceptibility to air degradation presents a significant challenge for commercialization. In this study, we develop an effective carbon coating strategy utilizing pitch to improve the air stability of Li₅FeO₄. The coating process results in the formation of a compact carbon layer on the surface of Li₅FeO₄ particles, enabling the coated Li₅FeO₄ to retain a high specific capacity of 743.4 mAh g⁻¹ after 72 h of exposure to air with 20% relative humidity. This retention represents 92.3% of its initial capacity and 85.7% of its theoretical maximum capacity. In contrast, uncoated Li₅FeO₄ undergoes rapid degradation, losing most of its electrochemical activity within just 4 h under identical conditions. Beyond improving air stability, the carbon coating enhances Li₅FeO₄’s specific capacity, rate capability, and cycling stability. To substantiate the practical application of carbon-coated Li₅FeO₄, we construct a pouch-type cell, which exhibits a 13.7% increase in energy density compared to the cell without the prelithiation additive. These findings collectively suggest that the carbon-coated Li₅FeO₄ represents a viable strategy for advancing the commercial deployment of this material in lithium-ion batteries.

As a lithium-supplementing agent, Li₅FeO₄ (LFO) is typically utilized to provide an additional lithium source for mitigating significant initial capacity loss, particularly when employing Si-based anodes. However, systematic investigations into the impact of LFO incorporation on the performance of cathode materials, as well as the determination of an optimal LFO loading amount, are still lacking. Herein, we first synthesize a high-capacity LFO (781.9 mA h g^-1) and assemble batteries using this LFO in conjunction with ultrahigh nickel ternary cathode material (NCM92). We then systematically investigate the effects of LFO incorporation on both the cathode material and overall battery performance. The results indicate that the inclusion of LFO enhances the initial discharge capacity of the full cell from 190.7 mA h g^-1 to 226.2 mA h g^-1. Moreover, the addition of LFO to the cathode can facilitate smoother lithium-ion migration, mitigate the polarization phenomenon, and reduce the electrochemical potential difference of the high-nickel cathode materials during the H2-H3 phase transition. Besides, it is discovered that the discrepancy between the theoretical and actual loading amounts of LFO is likely due to the involvement of some lithium ions in the formation of the solid electrolyte interface (SEI) film. Failure analyses confirm that the incorporation of LFO does not lead to the deposition of transition metal elements on the separator or anode. This study provides robust support for the potential of LFO in practical applications and validates its positive contributions to battery performance.