Abstract
Lithium ion battery becomes one of the most promising energy storage systems recently, because of its high theoretical energy density and high power. The Li2MnSiO4 as cathode material has been widely studied because it has high theoretical discharge capacity which is more than 300 mAh/g. However, due to its low electronic and ionic conductivity and structural instability, Li2MnSiO4 has poor cycle life and unobvious voltage platform. In this experiment, we used sol-gel method to synthesis Li2MnSiO4 and partially substituted with LiMnPO4 in order to improve performance by increasing its conductivity, improving its structural stability, and enhancing electrochemical reactivity. With the partial substitution of LiMnPO4, there was no LiMnPO4 phase synthesized. The materials remain less Pmn21 phase and more P121/n1 phase. The electrical performances of the one partially substituted with LiMnPO4 is better than that without substitution. The discharge capacity of Li2MnSiO4 which was not substituted was about 100 mAh/g at 0.05C and that substituted by 10 % LiMnPO4 was about 160 mAh/g at 0.05C having more obvious voltage platform as well.