电/离子导体双包覆的LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)锂离子电池阴极材料及其电化学性能  

Electron/ion Conductor Double-coated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) Li-ion Battery Cathode Material and Its Electrochemical Performance

作　　者：陈守潇 刘君珂 郑伟琛 魏国祯 周尧 李君涛 Chen Shouxiao;Liu Junke;Zheng Weichen;Wei Guozhen;Zhou Yao;Li Juntao(College of Energy,Xiamen University,Xiamen 361102,China;College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China;Xiamen Tungsten Co.,Ltd.,Xiamen 361026,China)

机构地区：[1]厦门大学能源学院,厦门361102 [2]厦门大学化学与化工学院,厦门361005 [3]厦门厦钨新能源材料股份有限公司,厦门361026

出　　处：《化学学报》2022年第4期485-493,共9页Acta Chimica Sinica

基　　金：厦门市重大科技项目(No.3502Z20201012)资助。

摘　　要：高镍三元材料 Li Ni_(0.8)Co_(0.1)Mn_(0.1)O_(2) (NCM)比容量高且成本低,但材料结构在电化学循环过程中的不稳定性影响了其大规模的应用,可采用表面包覆的策略来改善材料的结构稳定性,从而提高其电化学性能.本工作结合高速固相包覆法和高温烧结法,分别将电子导体氧化锡锑(ATO)和锂离子导体偏磷酸锂(LOP)共同包覆在 NCM 材料表面.双包覆后的 NCM 材料的电子电导率从 2.17×10^(-3) S·cm^(-1)提高至 1.02×10^(-2) S·cm^(-1),锂离子扩散系数也从 7.05×10^(-9) cm^(2)·s^(-1)提高至 2.88×10^(-8) cm^(2)·s^(-1).同时,NCM 表面的双包覆层可以在循环过程中阻止电极材料与电解液发生氧化还原反应,抑制材料不利相变,减少氧的析出,稳定材料结构.电化学性能测试表明,经过表面包覆后,NCM 材料在 1 C (180m A·g^(-1))的电流下和 2.7~4.3 V (vs.Li/Li^(+))的电压范围内,循环 150 周后容量为 161.1 m Ah·g^(-1),保持率为 87.1%,而在10 C 的充放电倍率下具有 133 m Ah·g^(-1)的可逆比容量.The Ni-rich layered cathode material LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) presents a high specific capacity and relatively low cost,however,the inherent structure instability during the electrochemical cycling process hinders its application widely.Universally,the strategy of surface coating can be used to improve the structural stability of the material and then improve its electrochemical performance.This work combines the high-speed solid-phase coating method and the high-temperature sintering method to coat the electronic conductor antimony tin oxide and lithium-ion conductor lithium metaphosphate on the surface of the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material,respectively.The electron/ion conductor double coating layer forms a charge conversion and transport channel on the surface of the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2).The electronic conductivity of the double-coated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material increased from 2.17×10^(-3) S·cm^(-1) to 1.02×10^(-2) S·cm^(-1),and the diffusion coefficient of lithium-ion also increased from 7.05×10^(-9) cm~2·s^(-1) to 2.88×10^(-8) cm~2·s^(-1).At the same time,due to strong P—O bonds and stable metal oxides,the double-coating layer on the surface of the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material can effectively restrain the irreversible phase transitions,and it also can inhibit the interfacial reactions under high electrode potential.The electrochemical performance test demonstrated that the cyclability and rate performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material improved due to surface modification.The cathode assembled with double-coated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material can maintain a reversible capacity of 161.1 mAh·g^(-1) after 150 cycles at 1 C(after being activated at 0.1 C for two cycles,1 C=180 mA·g^(-1)) during 2.7~4.3 V(vs.Li/Li^(+)),with a capacity retention of 87.1%.This coated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material also displays a specific capacity as high as 133 mAh·g^(-1) at 10 C.In comparison,the pristine LiNi_(0.8)Co_(0.1)Mn_(0.1)

关 键 词：锂离子电池 富镍阴极材料 电子导体 锂离子导体 快速充电 

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]