Synthesis Routes on Electrochemical Behavior of Co-Free Layered LiNi(0.5)Mn(0.5)O(2) Cathode for Li-Ion Batteries

Co-free layered LiNi(0.5)Mn(0.5)O(2) has received considerable attention due to high theoretical capacity (280 mAh g(−1)) and low cost comparable than LiCoO(2). The ability of nickel to be oxidized (Ni(2+)/Ni(3+)/Ni(4+)) acts as electrochemical active and has a low activation energy barrier, while the stability of Mn(4+) provides a stable host structure. However, selection of appropriate preparation method and condition are critical to providing an ideal layered structure of LiNi(0.5)Mn(0.5)O(2) with good electrochemical performance. In this study, Layered LiNi(0.5)Mn(0.5)O(2) has been synthesized by sol-gel and solid-state routes. According to the XRD, the sol-gel method provides a pure phase, and solid-state process only minimize the secondary phases to certain limit. The Ni(2+)/Mn(4+) content in the sol-gel process was higher than in the solid-state reaction, which may be due to the chemical composition homogeneity of the sol-gel samples. Regarding the electrochemical behavior, sol-gel process is better than solid-state reaction. The discharge capacity is 145 mAh/g and 91 mAh/g for the sol-gel process and solid-state reaction samples, respectively.