Lithium-rich layered oxide(LLO)cathode materials have drawn extensive attention due to their ultrahigh specific capacity and energy density.However,their commercialization is still restricted by their low initial coul...Lithium-rich layered oxide(LLO)cathode materials have drawn extensive attention due to their ultrahigh specific capacity and energy density.However,their commercialization is still restricted by their low initial coulombic efficiency,slow intrinsic kinetics and structural instability.Herein,a facile surface treatment strategy via gaseous phosphine was designed to improve the rate performance and capacity stability of LLOs.During the solid-gas reaction,phosphine reacted with active oxygen at the surface of LLOs due to its reductivity,forming oxygen vacancies and spinel phase at the surface region.As a result,Li ion conductivity and structural stability were greatly enhanced.The phosphinetreated LLOs(LLO@P)showed a layered-spinel hybrid structure and delivered an outstanding rate performance of156.7 mA h g^-1 at 10 C and a high capacity retention of 74%after 300 cycles at 5 C.展开更多
基金financial support from the Ministry of Science and Technology of China(MoST,2016YFA0200200)the National Natural Science Foundation of China(NSFC,21421001 and 51633002)+1 种基金Tianjin city(16ZXCLGX00100)111 Project(B12015)。
文摘Lithium-rich layered oxide(LLO)cathode materials have drawn extensive attention due to their ultrahigh specific capacity and energy density.However,their commercialization is still restricted by their low initial coulombic efficiency,slow intrinsic kinetics and structural instability.Herein,a facile surface treatment strategy via gaseous phosphine was designed to improve the rate performance and capacity stability of LLOs.During the solid-gas reaction,phosphine reacted with active oxygen at the surface of LLOs due to its reductivity,forming oxygen vacancies and spinel phase at the surface region.As a result,Li ion conductivity and structural stability were greatly enhanced.The phosphinetreated LLOs(LLO@P)showed a layered-spinel hybrid structure and delivered an outstanding rate performance of156.7 mA h g^-1 at 10 C and a high capacity retention of 74%after 300 cycles at 5 C.
