Novel composite anodes based on layered lithium transition metal nitrides for lithium secondary batteries

The Li-rich structure hinders the potential applications of the hexagonal lithium transition metal nitrides as insertion anodes for lithium ion batteries. This deterrent can be overcome by introducing a certain amount of spinel LiTi2O4 into the electrodes based on the above hosts. LiTi2O4 can extract lithium from the lithium transition metal nitrides and function as an inert-conducting material in the electrodes. The initial coulombic efficiency of ca. 100% is feasible by controlling the ratio of the nitrides to the LiTi2O4 in the electrodes. The composite electrode based on Li2.6Co0.2Cu0.2N and LiTi2O4 shows a volumetric capacity of 798 mAh cm−3 on the first cycle. After 80 cycles, 82% of the initial capacity can still be retained. Some factors influencing the electrode performance are presented and discussed.