Construction of cobalt vacancies in cobalt telluride to induce fast ionic/electronic diffusion kinetics for lithium-ion half/full batteries

Designing novel electrode materials with unique structures is of great significance for improving the performance of lithium ion batteries (LIBs). Herein, copper-doped Co1-x[email protected] carbon hollow nanoboxes (Cu-Co1-x[email protected] HNBs) have been fabricated by chemical etching of CuCo-ZIF nanoboxes, followed by a successive high-temperature tellurization process. The as-synthesized Cu-Co1-x[email protected] HNBs composite demonstrated faster ionic and electronic diffusion kinetics than the pristine [email protected] HNBs electrode. The existence of Co-vacancy promotes the reduction of Gibbs free energy change (∆GH*) and effectively improves the Li+ diffusion coefficient. XPS and theoretical calculations show that performance improvement is ascribed to the electronic interactions between Cu-Co1-xTe and nitrogen-doped carbon (NC) that trigger the shift of the p-band towards facilitation of interfacial charge transfer, which in turn helps boost up the lithium storage property. Besides, the proposed Cu-doping-induced Co-vacancy strategy can also be extended to other conversion-type cobalt-based material (CoSe2) in addition to as-obtained Cu-Co1-xSe2@NC HNBs anodes for long-life and high-capacity LIBs. More importantly, the fabricated LiCoO2//Cu-Co1-x[email protected] HNBs full cell exhibits a high energy density of 403 Wh kg−1 and a power density of 6000 W kg−1. We show that the energy/power density reported herein is higher than that of previously studied cobalt-based anodes, indicating the potential application of Cu-Co1-x[email protected] HNBs as a superior electrode material for LIBs.