Improvement in rate capability of lithium-rich cathode material Li[Li0.2Ni0.13Co0.13Mn0.54]O2 by Mo substitution

Abstract

Lithium-rich cathode material Li[Li0.2Ni0.13Co0.13Mn0.54]O2 doped with trace Mo is successfully synthesized by a sol-gel method. The X-ray diffraction patterns show that trace Mo substitution increases the inter-layer space of the material, of which is benefiting to lithium ion insertion/extraction among the electrode materials. The (CV) tests demonstrate the decrease of polarization, and on the other hand, the lithium ion diffusion coefficient (DLi) of the modified material turns out to be larger, which indicates a faster electrochemical process. As a result, the Mo doped material possesses high rate performance and good cycling stability, and the initial discharge capacity reaches 149.3 mAh g−1 at a current density of 5.0 °C, and the residual capacity is 144.0 mAh g−1 after 50 cycles with capacity retention of 96.5 % in the potential range of 2.0–4.8 V at room temperature.