Improvement in the electrochemical properties of LiNi0.5Mn1.5O4 lithium-ion battery cathodes prepared by a modified low temperature solution combustion synthesis

Abstract

The LiNi0.5Mn1.5O4 (LNM) spinel lithium-ion battery cathodes were prepared by a modified low temperature solution combustion synthesis method at 600°C for 3h. Structural analyses reveal that the modified method is an effective process to eliminate an impurity phase. In comparison with the LNM prepared by a conventional method, the modified sample has higher purity, better crystallinity, smaller amount of Mn3+ ions and higher structural ordering. It exhibits remarkably superior initial discharge specific capacity of 117.0mAh/g, and delivers a reversible capacity of ~116.0, 116.6, 113.8, 108.9 and 85.9mAh/g at 0.2C, 0.5C, 1C, 2C and 5C, respectively. While the LNM prepared by the conventional method offers a lower reversible capacity of ~96.3, 95.4, 89.1, 77.0 and 40.6mAh/g at the same rate. After 50 cycles, about 95.5% of reversible capacity is retained for the LNM prepared by modified method vs. 90.7% for the LNM prepared by the conventional method. It suggests that the modified method is a simple and effective method to prepare LiNi0.5Mn1.5O4 with high performance at low temperature and in short time.