The electrochemical performances of La2O3-doped ZnO in Ni-Zn secondary batteries

The La2O3-doped ZnO was synthesized successfully via a simple calcination method subsequent to a co-precipitation process. The X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images show that the as-prepared sample has a main wurtzite structure and a pie-like morphology. The electrochemical performances were investigated through galvanostatic charge-discharge, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. As the anode material, La2O3-doped ZnO has an initial discharge capacity of 455.7 mAh g−1 and a capacity retention ratio of 83.5% at 90th cycle, showing an obviously superior stability of cycle life compared with pure ZnO. Furthermore, La2O3-doped ZnO has a lower resistance and a better reversibility. All these results prove that the La2O3-doped ZnO can deliver a better electrochemical performance than pure ZnO in alkaline electrolyte.