Surface-targeted functionalization of nickel-rich cathodes through synergistic slurry additive approach with multi-level impact using minimal quantity

LiNi0.8Co0.1Mn0.1O_(2)(NCM811),a Ni-rich layered oxide,is a promising cathode material for high-energy density lithium-ion batteries(LIBs).However,its structural instability,caused by adverse phase transitions and continuous oxygen release,as well as deteriorated interfacial stability due to excessive electrolyte oxidative decomposition,limits its widespread application.To address these issues,a new concept is proposed that surface targeted precise functionalization(STPF)of the NCM811 cathode using a synergistic slurry additive(SSA)approach.This approach involves coating the NCM811 particle surface with 3-aminopropyl dimethoxy methyl silane(3-ADMS),followed by the precise deposition of ascorbic acid via an acid-base interaction.The slurry additives induce the formation of an ultra-thin spinel surface layer and a stable cathode–electrolyte interface(CEI),which enhances the electrochemical kinetics and inhibits crack propagation.The STPF strategy implemented by the SSA approach significantly improves the cyclic stability and rate performance of the NCM811 cathode in both half-cell and full-cell configurations.This work establishes a promising strategy to enhance the structural stability and electrochemical performance of nickel-rich cathodes and provides a feasible route to promote practical applications of high-energy density lithium-ion battery technology.

Silicon lithium-ion battery anode with enhanced performance： Multiple effects of silver nanoparticles

Silicon has been regarded as one of the most promising next generation lithium-ion battery anode. How- ever, the poor cyclic stability of the Si based anode has severely limited its practical applications, which is even worse with high mass loading density （〉1 mg cm^-2 ）. A new concept has been developed to enhance the electrochemical performance of the Si nanoparticle anode. Silver nanoparticles are composited with the silicon nanoparticles in a facile way for the first time. It is found that the mechanical properties of the Si electrode have been significantly improved by the incorporation of the silver nanoparticles, leading to enhanced cyclic performance. With the Si/Ag mass ratio of 4：1, the reversible specific discharge capacity is retained as l 156 mA h g^-1 after 100 cycles at 200 mAg^-1, which is more than three times higher than that of the bare silicon （318 mA h g^-1 ）. The rate performance has been effectively improved as well due to excellent electron conductivity of the silver nanoparticles.

通过构筑嵌覆型碳结构提升Nb_(2)O_(5)的储锂性能

嵌入型过渡金属氧化物因具有安全的工作电压、高比容量和快速的嵌锂能力而受到广泛关注.但低本征电导率特性严重影响其作为锂电负极材料的寿命和性能.本文通过简便易行、可规模化放大的二氧化碳热处理方法构筑了具有新型嵌覆型碳结构的Nb_(2)O_(5)/C纳米杂化材料.在控制碳含量的前提下,实现了颗粒聚集体内部表面可控碳包覆.以嵌覆型碳结构的Nb_(2)O_(5)/C纳米杂化材料为负极组装的锂离子电池在40 mA g(-1)电流密度下容量可达387 mA hg(-1),而在200 mA g(-1)电流密度下循环500次后,容量保持率在92%以上.采用电化学滴定、差分电化学质谱(DEMS)等方法对嵌覆型五氧化二铌/碳纳米杂化材料脱嵌锂动力学过程以及产气行为进行了研究.本文提出的嵌覆型碳结构有望为高性能嵌入型过渡金属氧化物的结构设计提供参考.