Synthesis of well-dispersed ZnO-Co-C composite hollow microspheres as advanced anode materials for lithium ion batteries

In this study, ZnO-Co-C composite hollow microspheres made up of massive nanometer-sized subunits are fabricated through a facile adsorption treatment at room temperature, followed by heating processing in inert atmosphere. When they function as active materials in lithium ion batteries, the as-obtained ZnO-Co-C composites show good electrochemical properties in terms of relatively high first coulombic efficiency, high specific capacity, distinguished cyclic property and exceptional rate capacity. ZnO-Co-C composite hollow microspheres possess an initial coulombic efficiency of about 70.1%, which is one of the best results for ZnO-based anodes reported. During repetitive lithiation-delithiation 300 times, a high discharge capacity of 794 mA h g(-1) is harvested at 200 mA g(-1). The unique advantages, including metal Co and carbon modification, hierarchical hollow architecture and the nanoscale building blocks, account for the superiority in electrochemical performance of the ZnO-Co-C composites.