Zn defective ZnCo2O4 nanorods as high capacity anode for lithium ion batteries

Zn defective ZnCo2O4 nanorods, made of nanoparticles in the size range 10–20 nm, re-arranged in tubular superstructures are investigated as lithium ion battery anode material. They are prepared by a step-wise synthetic procedure, consisting of a co-precipitation with a chelating agent assisted by a dispersing agent, autoclave treatment and subsequent calcination. Zn vacancies are, then, introduced by an alkaline etching procedure. An extensive structural and morphological characterization is performed by thermogravimetry coupled with differential thermal analysis, X-ray diffraction, X-ray photoelectron spectroscopy, surface area measurements, inductively coupled plasma atomic emission spectroscopy, scanning and transmission electron microscopies. The defective ZnCo2O4 nanorods-based anode exhibits a high specific capacity, i.e. 1398.8 mAh g−1, at the current density of 0.4 A g−1. The reversible charge/discharge lingers between 1140/1135.0 mAh g−1 and 1058.8/1051.4 mAh g−1, at the 200th cycle, with a high stability as indicated by CEs between 99.7% and 98.7%. A large average capacity is reinstated after cycling at high rates.