Optimized Synthesis and Electrochemical Performance of LiCoMnO₄ Cathode Material for Lithium-Ion Batteries

With a spinel structure, LiCoMnO₄ has been developed as a cathode material for lithium-ion batteries due to the existence of lithium-ion and valence-variable Co and Mn cations. The potential advantages for this cathode material come from the high energy density caused by the output voltage around 5.3 V. However, Li₂MnO₃ inactive impurity is generated during the synthesis, which affects its charge and discharge capacity. The effects of Li excess, particle size of precursor materials, forming pressure and sintering temperature on the purity of synthesized LiCoMnO₄ were discussed by orthogonal experimental study. An optimized material synthesis approach is obtained through the study and related electrochemical performance of the prepared samples were tested. The results show that, the initial specific capacity of the optimized 17# cathode material can be improved to 99.7 mAh·g^–1, with a coulombic efficiency of 93.3%. For the 1# cathode material, the specific capacity is 94.6 mAh·g^–1 and the value for coulombic efficiency is 94.2%. Big difference is observed for capacity retention after 100 cycles. Sample 17# showed high capacity retention of 79.4% when compared to the value of 41.6% for 1# sample. For the rate performance, the sample 17# presents a high capacity of 67.2 mAh·g^–1 even at 5 C current density. Such results indicate that the electrochemical performance of the material is greatly prompted, showing the high potential to serve as a candidate cathode for a new generation of lithium-ion batteries.