Electrochemical properties of Li-riched LiLi_(0.2)Co_(0.4)Mn_(0.4)O_2 cathode material for lithium ion batteries

摘要

The Li[Li_(0.2)Co_(0.4)Mn_(0.4)]O_2 cathode material was prepared by a sol-gel method. The X-ray diffraction (XRD) spectroscopic showed that the material was a solid solution of LiCoO_2 and Li_2MnO_3. The material showed a reversible discharge capacity of 155.6 mAhg~(-1) in the voltage window of 2.0-4.3 V after percharge to 4.6 V. While the material cycled in the same voltage window without precharge could only deliver capacity of 77.6 mAhg~(-1). This high capacity was attributed to the loss of oxygen and structural rearrangement in the precharge process.