A novel and green synthesis of mixed phase CoO@Co3O4@C anode material for lithium ion batteries

CoO composite materials had attracted wide attention due to their potential application in lithium ion batteries (LIBs). We report a green and novel solution method for making pristine Co3O4 and mixed phase CoO@Co3O4@C composite anode electrodes in LIBs. The anode materials characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD diffraction pattern reveals that composite anode contains as a major phase of CoO and small amounts of cubic Co3O4 and Co metal peaks are found as impurity phases. The SEM micrographs showed that CoO, Co3O4, and Co phases are distributed in amorphous carbon network. The electrochemical behavior of anodes material is investigated by galvanostatic discharge/charge measurements and cyclic voltammetry. The composite anode shows a reversible specific capacity approaching 447 +/- 5mAhg(-1) after 10cycles at 100 and 107 +/- 5mAhg(-1) after 50cycles at 500mAg(-1)as well as improved cyclic stability and excellent rate capability. The enhancement of the electrochemical performance is attributed to the good electric contact between the particles, easier lithium ion diffusion, and suppression of volume change of anode.