Effect of different MnO_2 precursors on the electrochemical properties of spinel LiNi_(0.5)Mn_(1.5)O_4 cathode active materials for high-voltage lithium ion batteries

摘要

LiNi_(0.5)Mn_(1.5)O_4 (LNMO) cathode materials with different morphologies are prepared via a facile template method using various MnO_2 precursors. The structures, morphologies and electrochemical properties of the as-prepared LiNi_(0.5)Mn_(1.5)O_4 samples are tested by various physical and electrochemical methods. The results of characterization show that the spinel LNMO cathode materials have good crystal structure and the MnO_2 precursors have no effect on the final products. Moreover, the specific morphology of LNMO is closely related to that of MnO_2 precursor, and further influence the electrochemical performance. In addition, the LNMO sample using NH_4HCO_3 as precipitant exhibits excellent rate capability and cyclic stability in all as-prepared samples. Cycled at 0.5 and 1 C, the discharge capacities of LNMO cathode active particles using NH_4HCO_3 as precipitant are 110.6 and 102.2 after 200 charge-discharge cycles, respectively, which are the largest compared with the LNMO using (NH_4)_2S_2O_8 and KMnO_4 as oxidants.