Abstract
The effect of partial substitution of Mg for Ni on a high-sodium and lithium-free layered P2-type Na45/54Mg6/54Ni12/54Mn34/54O2 cathode with high initial Coulombic efficiency and excellent cyclic stability has been investigated in this study.Based on the crystal structural analysis,the Mg doping can retain the P2 structure up to 4.3 V,thus restraining the detrimental phase transformation of P2-O2 during the Na-ion intercalation/deintercalation process.Therefore,the obtained Mg-doped P2-type cathode exhibits a reversible specific capacity of 109 mAh·g-1 at 0.1C between 2.0 and 4.3 V and a retention rate of 81.5％after 200 cycles at 1C.In addition,the full cell consisting of Mg-doped P2-type cathode and hard carbon anode shows a capacity retention rate of 85.6％after 100 cycles.This study provides new insight into the development of durable cathode mate-rials for sodium-ion batteries.
基金项目
National Natural Science Foundation of China(21978193)
Natural Science Foundation of Shanxi Province(20210302123107)
Natural Science Foundation of Shanxi Province(20181102005)
Natural Science Foundation of Shanxi Province(20181102019)
NETL
NSTL
万方数据