Regeneration of spent LiFePO4 as a high-performance cathode material by a simultaneous coating and doping strategy  

作　　者：Hui Tong Yi Li Gaoqiang Mao Chaolei Wang Wanjing Yu Yong Liu Mudan Liu 

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,China [2]Guangdong Provincial Key Laboratory of Development and Comprehensive Utilization of Mineral Resources,Guangzhou 510560,China [3]National&Regional Joint Engineering Research Center of Nonferrous Metal Resource Recycling,Changsha 410083,China [4]Engineering Research Center of the Ministry of Education for Advanced Battery Materials,Central South University,Changsha 410083,China [5]Institute of Resources Utilization and Rare Earth Development,Guangdong Academy of Sciences,Guangzhou 510560,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2023年第6期1162-1170,共9页矿物冶金与材料学报（英文版）

基　　金：supported by the Science and Technology Innovation Program of Hunan Province(No.2020SK2007);the Natural Science Foundation of Hunan Province(No.2019JJ50814);the Fundamental Research Funds for the Central Universities of Central South University(No.1053320211765);the Science and Technology Planning Project of Guangdong Province of China(No.2017B030314046);Guangdong Academy of Sciences for Innovation Capacity Building(No.2016GDASRC0201).

摘　　要：With the number of decommissioned electric vehicles increasing annually,a large amount of discarded power battery cathode material is in urgent need of treatment.However,common leaching methods for recovering metal salts are economically inefficient and polluting.Meanwhile,the recycled material obtained by lithium remediation alone has limited performance in cycling stability.Herein,a short method of solid-phase reduction is developed to recover spent LiFePO4 by simultaneously introducing Mg2+ions for hetero-atom doping.Issues of particle agglomeration,carbon layer breakage,lithium loss,and Fe3+defects in spent LiFePO4 are also addressed.Results show that Mg2+addition during regeneration can remarkably enhance the crystal structure stability and improve the Li+diffusion coefficient.The regenerated LiFePO4 exhibits significantly improved electrochemical performance with a specific discharge capacity of 143.2 mAh·g^(−1)at 0.2 C,and its capacity retention is extremely increased from 37.9%to 98.5%over 200 cycles at 1 C.Especially,its discharge capacity can reach 95.5 mAh·g^(−1)at 10 C,which is higher than that of spent LiFePO4(55.9 mAh·g^(−1)).All these results show that the proposed regeneration strategy of simultaneous carbon coating and Mg2+doping is suitable for the efficient treatment of spent LiFePO4.

关 键 词：spent LiFePO4 solid-phase reduction repair and regeneration cathode materials lithium-ion batteries 

分 类 号：TQ131.11[化学工程—无机化工] X734.2[环境科学与工程—环境工程]