The ultra-high nickel cathode material has important application prospect in power lithium-ion batteries.However,the poor structural stability and serious surface/interfacial side reactions during long cycles severely...The ultra-high nickel cathode material has important application prospect in power lithium-ion batteries.However,the poor structural stability and serious surface/interfacial side reactions during long cycles severely hinder the material's practical application.In this paper,Cs^(+)doping and polymethyl methacrylate(PMMA)coating are used to synergistically modify the NCM955 material.The results show that the corresponding discharge specific capacity of NCMCs-2@P-2 material reaches 152.02 m Ah/g at 1 C(1 C=200 m A/g)and 125.66 m Ah/g at 5 C after 300 cycles,and the capacity retention is 78.11%and72.21%,respectively.In addition,it still maintains 156.36 m Ah/g discharge specific capacity at 10 C,and these rate and cycle properties exceed those reported on ultra-high nickel cathode material.Moreover,NCMCs-2@P-2 material has higher migration energy barrier of Ni^(2+)and lower migration energy barrier of Li+than that of NCM955 material.Therefore,NCMCs-2@P-2 material has excellent electrochemical properties,which has been proved by a series of structural characterization,theoretical calculation and performance test.The synergistic enhancement of Cs^(+)doping and PMMA coating accelerates lithium ion diffusion kinetics,stabilizes crystal structure,and inhabits surface/interface side reaction.展开更多
基金supported the National Science Foundation of China(Nos.22362011,22169007,51804199)the Science and Technology Major Project of Guangxi(No.AA19046001)+2 种基金the Open Research Fund of Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials(Nos.EMFM20201105,EMFM20181119)Shenzhen Medical Research Fund(No.20231211121324001)Shenzhen Science and Technology Program(No.KQTD20180412181422399)。
文摘The ultra-high nickel cathode material has important application prospect in power lithium-ion batteries.However,the poor structural stability and serious surface/interfacial side reactions during long cycles severely hinder the material's practical application.In this paper,Cs^(+)doping and polymethyl methacrylate(PMMA)coating are used to synergistically modify the NCM955 material.The results show that the corresponding discharge specific capacity of NCMCs-2@P-2 material reaches 152.02 m Ah/g at 1 C(1 C=200 m A/g)and 125.66 m Ah/g at 5 C after 300 cycles,and the capacity retention is 78.11%and72.21%,respectively.In addition,it still maintains 156.36 m Ah/g discharge specific capacity at 10 C,and these rate and cycle properties exceed those reported on ultra-high nickel cathode material.Moreover,NCMCs-2@P-2 material has higher migration energy barrier of Ni^(2+)and lower migration energy barrier of Li+than that of NCM955 material.Therefore,NCMCs-2@P-2 material has excellent electrochemical properties,which has been proved by a series of structural characterization,theoretical calculation and performance test.The synergistic enhancement of Cs^(+)doping and PMMA coating accelerates lithium ion diffusion kinetics,stabilizes crystal structure,and inhabits surface/interface side reaction.
