The preparation and electrochemical performance of In(OH)3-coated Zn-Al-hydrotalcite as anode material for Zn-Ni secondary cell

In(OH)3-coated Zn-Al-hydrotalcite is prepared by homogeneous precipitation method. The X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images reveal that the In(OH)3 is successfully coated on the surface of the Zn-Al-hydrotalcite particles. And about 2.5 wt% of coating is determined through the energy dispersive X-ray spectrum (EDS). The electrochemical performance of In(OH)3-coated Zn-Al-hydrotalcite is investigated by cyclic voltammetry (CV), electrochemical impedance spectroscope (EIS), Tafel polarization curves and galvanostatic charge-discharge measurements. The EIS exhibits a higher charge-transfer resistance and the Tafel polarization curves reveal a more positive corrosion potential for the In(OH)3-coated Zn-Al-hydrotalcite, in comparison with the pristine Zn-Al-hydrotalcite and the mixture of Zn-Al-hydrotalcite and In(OH)3. After 50 cell cycles, the In(OH)3-coated Zn-Al-hydrotalcite retains a specific discharge capacity of 364.0 mAh g−1 with a retention rate of 96.9%, which is much superior to that of 262.2 mAh g−1 with a retention rate of 67.6% for the pristine Zn-Al-LDHs and 299.2 mAh g−1 with a retention rate of 81.2% for the mixture of Zn-Al-LDHs with In(OH)3.