Yannan 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.

Developing green and sustainable regeneration technologies for spent lithium‐ion battery cathode materials is of great significance for establishing a self‐sufficient and sustainable production model. In this study, full utilization of all metal components in spent LiMn ₂ O ₄ cathode materials is achieved through a strategy involving the directional separation of manganese and lithium. Based on the Ostwald ripening principle, spent LiMn ₂ O ₄ is regenerated into high‐performance single‐crystal cathodes. The recycled single‐crystal lithium manganate (R‐LMO) cathode mitigates lattice strain, suppresses Jahn‐Teller effect‐driven irreversible phase transitions, and enhances structural integrity. Simultaneously, the introduction of oxygen vacancies (OVs) lowers the Li ⁺ diffusion energy barrier, thereby improving lithium storage performance in R‐LMO. Compared to commercial LiMn ₂ O ₄ (LMO), the R‐LMO cathode exhibits superior electrochemical performance at both ambient and elevated temperatures (55°C). After 1000 cycles at 1C, the capacity retention rate of recycled R‐LMO reached 81.2%, surpassing that of LMO (68.6%). Moreover, this method avoids the introduction of external ions that could contaminate the final product and generates no chemical waste during the recycling process, eliminating the need for post‐treatment of waste streams or effluents. This work provides new insights into component separation from spent cathodes and lays the foundation for sustainable, cobalt‐free cathode production.

Cobalt‐free LiNi _0.5 Mn _1.5 O ₄ (LNMO) has recently emerged as a highly promising cathode material owing to its benefits of a high operating voltage platform (≈4.7 V vs Li), high theoretical energy density (≈650 Wh kg ⁻¹ ), eco‐friendliness, and resource abundance. However, it has also demonstrated low cycle and poor rate performances. Researchers have hitherto identified multiple LNMO failure and degradation mechanisms, including the Jahn‐Teller effect, Transition Metal (TM) dissolution, electrolyte decomposition, and Oxygen Vacancies (OVs). The Jahn‐Teller effect causes structural material degradation, while TM dissolution could lead to the loss of reactive species and interfacial side reactions. On the other hand, OVs and electrolyte decomposition accelerate capacity decay. Notably, deeply understanding LNMO structural failure mechanisms and the targeting of corresponding modifications presents a vital avenue for modulating its surface‐interface structure and improving its electrochemical performance. Although researchers have extensively investigated the failure mechanisms of LNMO to elucidate its modification strategies, a comprehensive and detailed summary of the latest research advancements has yet to be provided. In this work, the research background, encompassing the advantages and disadvantages of LNMO cathode materials, is first introduced. The crystal structure and discharge mechanisms, among other fundamental principles of LNMO, are subsequently analyzed. Finally, recent research findings on the aforementioned failure mechanisms in high‐voltage spinel LNMO are synthesized. Subsequently, a critical assessment of recent advancements in modification strategies targeting the failure mechanisms of LNMO is performed, encompassing the tools employed (e.g., doping modification, surface coating, morphology and size management, and surface orientation management) as well as their synergistic effects. Finally, potential future research directions to guide the rational design of high‐performance LNMO, particularly manganese‐based spinel cathode material, are proposed.

Silicon suboxide (SiOx) anode materials are sought to substitute graphite-based anodes due to their high theoretical capacity and lower volume expansibility. Present chemical vapor deposition industrial production inevitably produces about 15 wt % submicro SiOx wastes. To improve the reuse of submicro SiOx wastes in a more economical, efficient, and sustainable way, present research focuses on exploring spherical porous SiOx/poly(acrylic acid) (PAA) microparticles via a spray-drying process to enhance resilience and adhesivity. The PAA polymer membrane uniformly coats the SiOx matrix via strong hydrogen bond interactions, providing mechanical strength to whole particles. The availability of polymer also possesses excellent electrochemical stability and adhesion, remaining almost free from pulverization during cycling. In half-cell testing, the synthesized micro SiOx/PAA particles demonstrate a higher initial capacity efficiency of 68% compared to that of submicro SiOx and a high reversible capacity of 1102 mAh g^-1 with a fading rate of 0.036% per cycle after 200 cycles at 2 A g^-1. Even after 1000 ultralong cycles, the capacity still remains above 200 mAh g^-1. The full-cell measurement shows a capacity of 160.25 mAh g^-1 for 600 cycles, suggesting their practicality for industrial production. Microsized SiOx anodes have shown impressive performance, achieving high Coulombic efficiency (>99.8%), exceptional rate capability, and outstanding cycling stability over 600 cycles.