Superior cycle stability and high rate capability of Zn-Al-In-hydrotalcite as negative electrode materials for Ni-Zn secondary batteries

Zn-Al-In layered double hydroxides (LDHs) are synthesized by hydrothermal method and investigated as negative electrode materials for Ni-Zn batteries. The Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show the as-prepared samples are well-crystallized and hexagon structure. The electrochemical performances of Zn-Al-LDHs and Zn-Al-In-LDHs with different Zn/Al/In molar ration are investigated by the cyclic voltammograms (CV), Tafel polarization and galvanostatic charge-discharge measurements. Zn-Al-LDHs shows good stability in the first 300-cycles. However, during the subsequent cycles, the discharge capacity decreases with increasing of the cycles. Compared with Zn-Al-LDHs, Zn-Al-In-LDHs with different Zn/Al/In molar rations, especially the sample of Zn/Al/In = 3:0.75:0.25 (molar ration) have higher discharge capacity and more stable cycling performances. This battery can undergo at least 800 charge-discharge cycles at constant current of 1C without dendrite and short circuits. The discharge capacity of Zn-Al-In-LDHs after the 800th cycle remains about 380 mAh g−1. Zn-Al-In-LDHs possess a high rate capability to meet the needs of high-storage applications.