Mitigating kinetic hindrance of single-crystal Ni-rich cathodes through morphology modulation,nickel reduction,and lithium vacancy generation achieved by terbium doping  

作　　者：Jiyuan Jian Shuang Lin Guokang Han Xianglian Zhan Yinghui Shan Rang Xiao Ziwei Liu Dandan Sun Xin Zhang Qingjie Zhou Geping Yin Hua Huo Yulin Ma Pengjian Zuo Xinqun Cheng Chunyu Du 

机构地区：[1]State Key Laboratory of Space Power-sources,School of Chemistry and Chemical Engineering,Harbin Institute of Technology,Harbin 150001,Heilongjiang,China [2]Zibo Torch Energy Co.Ltd,Zibo 255051,Shandong,China

出　　处：《Journal of Energy Chemistry》2024年第10期566-574,I0012,共10页能源化学（英文版）

基　　金：financial support from the horizontal project“Research and Application of All-Solid-State Lithium-Ion Battery Technology” (MH20220255)from Zibo Torch Energy Co.,Ltd;the Heilongjiang Touyan Innovation Team Program (HITTY20190033);Zibo Torch Energy Co.,Ltd.;China State Shipbuilding Corporation,Limited for their financial support。

摘　　要：Single crystallization has proven to be effective in enhancing the capacity and stability of Ni-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(SNCM)cathode materials,particularly at high cut-off voltages.Nevertheless,the synthesis of high-quality single-crystal particles remains challenging because of severe particle agglomeration and irregular morphologies.Moreover,the limited kinetics of solid-phase Li^(+)diffusion pose a significant concern because of the extended diffusion path in large single-crystal particles.To address these challenges,we developed a Tb-doped single-crystal LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2)(SNCM-Tb)cathode material using a straightforward mixed molten salt sintering process.The Tb-doped Ni-rich single crystals presented a quasi-spherical morphology,which is markedly different from those reported in previous studies.Tb^(4+)oping significantly enhanced the dynamic transport of Li^(+)ions in the layered oxide phase by reducing the Ni valence state and creating Li vacancies.A SNCM-Tb material with 1 at%Tb doping shows a Li^(+)diffusion coefficient up to more than 9 times higher than pristine SNCM in the non-diluted state.In situ X-ray diffraction analysis demonstrated a significantly facilitated H1-H2-H3 phase transition in the SNCM-Tb materials,thereby enhancing their rate capacity and structural stability.SNCM-Tb exhibited a reversible capacity of 186.9 mA h g^(-1)at 5 C,retaining 94.6%capacity after 100 cycles at 0.5 C under a 4,5 V cut-off.Our study elucidates the Tb^(4+)doping mechanisms and proposes a scalable method for enhancing the performance of single-crystal Ni-rich NCM materials.

关 键 词：Lithium-ion batteries Ni-rich layered oxides Single crystals Tb^(4+) doping Li^(+) diffusion kinetics 

分 类 号：TB34[一般工业技术—材料科学与工程] TM912[电气工程—电力电子与电力传动]