Enhanced electrochemical performance of nanoscale single crystal NMC811 modification by coating LiNbO_(3)  

作　　者：Fengyu Zhang Yali Liang Zhangran Ye Lei Deng Yunna Guo Ping Qiu Peng Jia Qiaobao Zhang Liqiang Zhang 

机构地区：[1]Clean Nano Energy Center State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China [2]School of New Energy and Materials,China University of Petroleum Beijing,Beijing 102249,China [3]Hebei Key Laboratory of Applied Chemistry,College of Environmental and Chemical Engineering,Yanshan University,Qinhuangdao 066004,China [4]State Key Laboratory of Physical Chemistry of Solid Surfaces,College of Materials,Xiamen University,Xiamen 361005,China

出　　处：《Chinese Chemical Letters》2024年第5期514-518,共5页中国化学快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.52022088,51971245,51772262,U20A20336,21935009);Natural Science Foundation of Hebei Province(Nos.F2021203097,B2020203037);China Postdoctoral Science Foundation(No.2021M702756)。

摘　　要：Single crystallization is an important strategy to resolve intergranular cracks and unnecessary side reactions with electrolytes in layered transition metal oxide cathodes LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811).Due to the limitations of high-temperature sintering and multi-step calcination,single crystal NMC811 generally shows irregular particles with a size of 2-3μm.However,the prolonged Li-ion diffusion pathway and the stress generated by the uneven de-/intercalation sluggish Li-ion diffusion kinetics,what is more,cause structural damage such as intragranular cracks.A slow Li extraction rate or particle size reduction will ameliorate the structural damage and improve the cycling stability.As the most promising cathodes for next-generation power batteries,NMC811 required fast charge performance and cycle stability.Particle size reduction appears to be the displacement option.Nanonization is an effective strategy to mitigate intragranular cracks of single crystal NMC811.However,the serious aggregation and increased specific surface area become new challenges.In this article,we synthesized monodisperse nanoscale single crystal NMC811 by molten salt method and modified the surface by LiNbO3 coating.The electrochemical performance shows that nanoscale single crystal NMC811 has faster kinetic and higher capacity retention,so the strategy of combining nanonization and surface coating is an alternative way to prepare high specific capacity and cycle stable single crystal NMC811.

关 键 词：Ni-rich NMC811 Molten salt method Nanonization Surface coating Micron cracks 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ131.11[化学工程—无机化工]