Titanicone-derived TiO2 quantum dot@carbon encapsulated ZnO nanorod anodes for stable lithium storage

摘要

To address the issues of large volume expansion and low electrical conductivity of ZnO anode nano-materials during lithium ion battery operation, herein we engineered a rod-like ZnO anode with robust and conductive TiO2 quantum dot (QD)@carbon coating derived from molecular layer deposited titanicone, in which the TiO2 QDs are well confined inside the carbon layer. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) confirm the formation of TiO2 QDs and carbonization of fumaric acid in hybrid films after annealing in H-2 atmosphere at 700 degrees C. Benefiting from a unique protective layer design, the prepared TiO2 QD@carbon@ZnO nanorod (NR) anodes display outstanding cycling performance with a discharge capacity of 1154 mA h g(-1) after 100 cycles and 70% capacity retention, along with a high rate capacity of 470 mA h g(-1) for 500 cycles at 2 A g(-1). Moreover, our work demonstrates an innovative and promising approach toward a robust and conductive metal oxide QD@carbon nanocomposite layer for electrode materials in the future.