Layered double hydroxide/carbon nanotubes composite as a high performance anode material for Ni–Zn secondary batteries

Abstract

Nanostructured Zn–Al layered double hydroxide (LDH) and carbon nanotubes (CNTs) have been successfully assembled to form LDH/CNT composite by electrostatic force. The morphology and microstructure of LDH/CNT composites were investigated by transmission electron microscopy and X-ray diffractometer. The assembly mechanism of LDH with CNTs was also discussed. Furthermore, the unique three-dimensional composite thus prepared was used as a new anode material for Ni–Zn secondary batteries to enhance the cell performance for the first time. The electrochemical performances of LDH/CNT composite as anode active material for Ni–Zn cells were investigated by galvanostatic charge/discharge cycling and cyclic voltammogram. The obtained results clearly demonstrated that the LDH/CNT composite had superior cycle stability compared with the conventional ZnO and Zn–Al–LDH, and the discharge capacity could maintain 390mAhg−1 after 200 cycling tests. At the same time, the LDH/CNT composite also exhibited lower charge plateau voltage and higher discharge plateau voltage, and the average utilization ratio of the anode could reach 95.6%. These results indicated that this kind of composite is a promising anode material for Ni/Zn cells. It exhibits a high capacity (∼400mAhg−1) and high cycling stability.