Yiyong Zhang

LiNi _0.8 Co _0.1 Mn _0.1 O ₂ (NCM811) cathode material has attracted considerable attention because of its potential to achieve substantially higher energy densities, but the practical deployment of NCM811 remains hindered by severe interfacial and structural degradation during repeated cycling. Atomic layer deposition (ALD) was employed in this study to construct an amorphous Li─Si─O (LSO) coating layer with different thicknesses on the surface of NCM811 cathode materials, and their effects on the structural characteristics, interfacial properties, and electrochemical performance were systematically investigated. Among all the samples, 50 LSO@NCM811 exhibits the best electrochemical performance, retaining a discharge capacity of 115.96 mAh g ⁻¹ after 500 cycles at 1 C under a cutoff voltage of 4.3 V. By constructing a stable and ionically conductive interfacial protective layer, the LSO coating achieves the synergistic optimization of interfacial stability, structural stability, and electrochemical kinetics, thereby markedly enhancing the electrochemical performance of NCM811 cathode materials. This work provides important insights into interfacial engineering design for high‐nickel layered cathode materials of lithium‐ion batteries.

Uncontrolled Li ₂ S accumulation and high nucleation barriers severely hinder the sulfur utilization and cycle lifespan of lithium‐sulfur batteries (LSBs). Herein, we report an advanced bimetallic Mo ₂ V ₂ C ₃ T _x MXene as a functional separator modifier designed to accelerate the Li ₂ S nucleation and growth kinetics. Compared with V ₄ C ₃ T _x , strategic substitution of Mo ²⁺ effectively modulates the d ‐orbital occupancy of V ²⁺ centers. This electronic reconfiguration drives an upshift of the d ‐band center toward the Fermi level, accompanied by a significant broadening of the d ‐band. Theoretical calculations combined with in situ analyses reveal that the unique Mo‐V bimetallic coupling induces d ‐orbital delocalization, which strengthens d‐p orbital hybridization between the Mo ₂ V ₂ C ₃ T _x and polysulfides, ultimately achieving an isotropic electric field distribution. This precise modulation dictates the Li ₂ S deposition morphology, facilitating the isotropic growth of ultra‐uniform 3D spheres while maintaining high interfacial Li ⁺ flux. Consequently, the full battery exhibits a low‐capacity fading rate of 0.017% per cycle after 1500 cycles at 2 C. Even under a high sulfur loading of 6.8 mg cm ⁻² , the cell retains 92.1 of its initial capacity over 200 cycles at 1 C. This work establishes a new paradigm for the structure‐property relationship between Li ₂ S deposition morphology and electrochemical performance by employing a bimetallic coupling strategy.

Developing efficient and durable Fe‐based electrocatalysts for the hydrogen evolution reaction (HER) across a broad pH range remains challenging because of sluggish interfacial charge transfer, inefficient water activation, limited active‐site accessibility, and insufficient structural stability. Herein, hierarchical porous S‐ FeS ₂ /Fe ₃ O ₄ ‐CNT microspheres are constructed to integrate FeS ₂ /Fe ₃ O ₄ heterointerfaces, interconnected carbon nanotube networks, and penetrative mass‐transport channels. Spectroscopic characterization, operando Raman analysis, and density functional theory calculations reveal that interfacial electronic redistribution at the FeS ₂ /Fe ₃ O ₄ heterojunction facilitates water adsorption and dissociation while optimizing H ^* adsorption energetics. The CNT framework provides continuous electron‐transport pathways, whereas three‐dimensional tomography and permeability simulations demonstrate that accessible heterointerfaces are distributed throughout the microspheres and connected pores promote electrolyte transport to the internal active sites. Consequently, S‐FeS ₂ /Fe ₃ O ₄ ‐CNTs exhibit competitive HER activity across acidic, alkaline, and neutral seawater, requiring overpotentials of 273.52, 82.97, and 248.04 mV, respectively, to reach 10 mA cm ⁻² , together with long‐term operational stability. Moreover, the S‐FeS ₂ /Fe ₃ O ₄ ‐CNTs||RuO ₂ electrolyzer delivers lower cell voltages than the Pt/C||RuO ₂ benchmark under identical seawater electrolysis conditions. This work establishes a multiscale design strategy for earth‐abundant electrocatalysts by coupling interfacial electronic regulation, conductive‐network construction, active‐site accessibility, and mass‐transport engineering.

In recent years, anode-free lithium metal batteries (AFLMBs) have garnered significant attention as prospective next-generation high-energy batteries. However, the advancement of high-performance AFLMBs is severely impeded by challenges such as the uncontrolled growth of lithium dendrites and excessive volume expansion during cycling. Consequently, the design of three-dimensional (3D) lithiophilic carbon-based hosts to substitute conventional metal current collectors has emerged as a promising strategy for constructing high-performance AFLMBs. Herein, we present a critical and timely review of recent advances in the design of 3D lithiophilic carbon-based hosts for AFLMBs. Specifically, the intrinsic properties of various carbon materials, such as graphene, carbon nanotubes, porous carbon and carbon fibers, and their applications in AFLMBs, are first summarized. This is followed by a systematic classification of lithiophilic modification strategies, including surface heteroatom doping, surface decorating, and lithiophilic structural engineering and framework design, along with their research progress. Furthermore, the classifications, mechanisms, and structural configurations of lithiophilic gradient designs for 3D carbon-based hosts are summarized, with a specific focus on their application in high-performance AFLMBs. Finally, future challenges and perspectives regarding the lithiophilic structural design and practical application of novel 3D lithiophilic carbon-based hosts are proposed, offering valuable insights for the development of advanced AFLMBs.

The poor thermal stability of commercial polyethylene (PE) separators hinders the further application of lithium-ion batteries (LIBs), yet previous modifications struggle to balance between safety and electrochemical performance. This study proposes an interface modification strategy by forming a poly(melamine terephthalamide) (PTM) coating on the PE separator surface, constructing a “thermal–mechanical–electrochemical synergistic barrier”. The PTMs@PE separator achieves synergistic improvements in thermal shutdown behavior, thermal stability, mechanical strength, and electrochemical compatibility by taking advantage of the temperature-sensitive response of the PE separator, the flame-retardants of the rigid conjugated skeleton with the high nitrogen of PTM, and the electrolyte-affinity of its functional groups. Importantly, the principles between the molecular structure of the PTM coating and the thermal behavior is verified. The results demonstrate that PTM participates in the decomposition process of the PE separator and slows down the degradation rate of the PE chain structure, thereby resulting in a wide-temperature-range thermal shutdown temperature. The PTMs@PE effectively reduces the risk of runaway. The PTMs@PE separator achieves outstanding electrochemical compatibility, achieving a capacity retention rate of 99.27% at 2 C for 500 cycles. Notably, the separator shows high potential for scalable fabrication. This work provides a novel material system and technical pathway for developing highly safe and high-performance LIB separators.

For lithium-sulfur batteries (LSBs), transition region metals offer d electron counts from 1 to 10, making them an ideal platform to study electronic configuration and catalytic performance. This study selects zinc and cobalt because their 3d orbitals lie at two extremes: Zn2+ has a fully filled [Ar]3d10 configuration, while Co2+ has an unsaturated [Ar]3d7 configuration. Such extreme differences reveal a long overlooked hidden variable: the transition region d electron count. Using Zn(TFSI)2 and Co(TFSI)2 as model additives for LSBs, we demonstrate that the decisive factor is not the metal type but the 3d orbital occupancy. This hidden variable leads the two systems toward distinct pathways in catalyzing polysulfide conversion and suppressing lithium dendrites.In the d10 system (Zn2+), an electric field drives Zn2+ to react with polysulfides, forming an in situ ZnS nanocatalytic interface. This interface accelerates sulfur redox and suppresses shuttling, but the fully filled d orbital causes strong electron localization, offering limited dendrite suppression. In the d7 system (Co2+), the higher d band center induces strong orbital hybridization, generating ultrafine CoS nanocrystals with abundant defects for targeted polysulfide capture. A reversible Co2+/Co3+ redox cycle lowers the reaction barrier and accelerates conversion kinetics. Moreover, the unsaturated 3d7 configuration enables an electron/ion dual conductive interface, significantly inhibiting lithium dendrites. The d10 system is far inferior in dendrite suppression. Thus, the transition region d electron count is the overlooked hidden variable for LSBs, and understanding it enables rational design of high performance additives.

For lithium-sulfur batteries (LSBs), transition region metals offer d electron counts from 1 to 10, making them an ideal platform to study electronic configuration and catalytic performance. This study selects zinc and cobalt because their 3d orbitals lie at two extremes: Zn2+ has a fully filled [Ar]3d10 configuration, while Co2+ has an unsaturated [Ar]3d7 configuration. Such extreme differences reveal a long overlooked hidden variable: the transition region d electron count. Using Zn(TFSI)2 and Co(TFSI)2 as model additives for LSBs, we demonstrate that the decisive factor is not the metal type but the 3d orbital occupancy. This hidden variable leads the two systems toward distinct pathways in catalyzing polysulfide conversion and suppressing lithium dendrites.In the d10 system (Zn2+), an electric field drives Zn2+ to react with polysulfides, forming an in situ ZnS nanocatalytic interface. This interface accelerates sulfur redox and suppresses shuttling, but the fully filled d orbital causes strong electron localization, offering limited dendrite suppression. In the d7 system (Co2+), the higher d band center induces strong orbital hybridization, generating ultrafine CoS nanocrystals with abundant defects for targeted polysulfide capture. A reversible Co2+/Co3+ redox cycle lowers the reaction barrier and accelerates conversion kinetics. Moreover, the unsaturated 3d7 configuration enables an electron/ion dual conductive interface, significantly inhibiting lithium dendrites. The d10 system is far inferior in dendrite suppression. Thus, the transition region d electron count is the overlooked hidden variable for LSBs, and understanding it enables rational design of high performance additives.

Silicon (Si) anodes possess ultrahigh theoretical capacity and are regarded as highly promising candidates for next-generation lithium-ion batteries (LIBs). However,their practical deployment remains hampered by drastic volume fluctuations and rapid capacity decay during cycling. To address these challenges, we propose an innovative aqueous physically cross-linked binder, which is fabricated by compounding tannic acid (TA) containing pyrogallol groups with tremella polysaccharide (TP) rich in carboxyl and hydroxyl groups. Via the synergistic effects of hydrogen bonds and covalent bonds between the components, a stable cross-linked network structure is constructed. This unique chemical structure not only enhances the bonding strength and mechanical robustness (1.83 N), effectively dissipating the stress and strain induced by the volume change of Si particles, but also establishes a robust conductive framework to facilitate electron transfer. The Si anode employing the optimized TA-TP binder demonstrates high initial Coulombic efficiency, excellent rate capability (839 mAh g-1 at 2 C) and remarkable cyclic stability (1360 mAh g-1 after 100 cycles at 0.1 C, 1252 mAh g-1 after 100 cycles at 0.5 C). This study presents an innovative strategy for preparing high-performance Si-based anodes, which leverages the structural characteristics of polysaccharide molecules to construct a three-dimensional (3D) spatial cross-linked network, thereby significantly improving the cyclic stability of the electrode. This strategy can be extended to other high-capacity electrode materials that undergo significant volume expansion during cycling, exhibiting broad applicability. Overall, this work provides novel insights and technical references for the development of low-cost, highly adaptable binders for Si-based anodes, and holds great significance for promoting the engineering application of high-capacity anode materials in next-generation LIBs.

Aqueous zinc-ion batteries present several advantages, including high safety and low cost. However, severe dendrite growth and side reactions at the zinc anode significantly impede their cycle life and efficiency. This study proposes a zinc deposition regulation strategy based on a synergistic “chelation-relay” mechanism achieved by constructing a phthalocyanine functional layer on the surface of a cellulose separator. The phthalocyanine layer, which is rich in nitrogen coordination centers, effectively chelates Zn²⁺, reshaping the electrode/electrolyte interface structure and inhibiting side reactions. Its macrocyclic conjugated architecture functions as an “ion relay”, facilitating reversible storage and providing ordered migration channels for Zn²⁺, thereby alleviating concentration polarization and promoting uniform deposition. COMSOL simulation results demonstrate that this functional layer can homogenize the interfacial electric field and Zn²⁺ flux, thereby suppressing the “tip effect” associated with dendrite formation. Consequently, stable zinc deposition and stripping over 1000 cycles under conditions of 1 mA cm⁻² and 1 mAh cm⁻² yield an average coulombic efficiency of 99.1%. Furthermore, the Zn/I₂ full cell exhibits a capacity retention rate of 98.83% after 10 000 cycles at a discharge rate of 1 A g⁻¹. These findings underscore the potential of phthalocyanine to regulate zinc deposition, contributing to the development of high-performance aqueous zinc-ion batteries.