Increased rate capability of Li⁺ doped LiNi_0·5Mn_1·5O₄ prepared by a novel solution combustion synthesis

Abstract

High voltage LiNi_0·5Mn_1·5O₄ and Li_1·1Ni_0·5Mn_1·4O₄ spinels are prepared by a novel solution combustion method at 600°C for 4 h. Although the phase composition, ordered structure, micromorphology and the amount of Mn³⁺ of the products with or without Li⁺ doping are similar, Li_1·1Ni_0·5Mn_1·4O₄ with Li⁺ doping shows superior rate capability. The capacity retention ratio of Li_1·1Ni_0·5Mn_1·4O₄ with Li⁺ doping takes 46 times as much as that without Li⁺ doping at 5 C rate, and the polarisation of Li_1·1Ni_0·5Mn_1·4O₄ shows smaller number as well. It suggests that doping Li⁺ is more effective and promising for improving the rate capability of LiNi_0·5Mn_1·5O₄ by solution combustion method.

Keywords:

• Lithium ion batteries
• Li⁺ doping
• Solution combustion method
• Electrochemical properties

Acknowledgements

The present work was supported by the National Natural Science Foundation of China (grant nos. 51362011 and 51362012), Natural Science Foundation of Yunnan Province (grant no. 2012FB173), the Chemistry Discipline Master's Site Construction Open Foundation of Honghe University of Yunnan Province (grant no. HXZ1309) and Innovation and Entrepreneurship Training Program (grant no. DCXL1319).