The surface-modified effects of Zn anode with CuO in Zn-air batteries

Copper oxide nanoparticles (CuO-NPs) can be used to prevent dendrite formation and increase the reversibility of Zn anode. The zinc surface was modified with CuO and the Cu source used was copper nitrate. It also contained 0.1 wt%, 0.5 wt%, 1.0 wt%, and 3.0 wt% CuO by weight of zinc. The morphologies of the Zn surfaces modified by CuO-NPs were observed by scanning electron microscopy (SEM). The structures of the surface-modified and bare zinc powders showed that the modification did not affect the crystal structure, but Cu 2p details from XPS were detected in the form of a satellite peak of CuO. SEM images of CuO modified on the zinc particles revealed homogeneous modification on the Zn surface. The use of an appropriate CuO particle can prevent direct contact with Zn and KOH electrolyte, and minimize side reactions within the batteries. In a DC-cycling test, the 0.1 wt% CuO-modified Zn anode powder provided the best cycle performance up to 24 h. A surface-modified zinc electrode can increase reversibility and reduce self-discharge with electrochemical stability. The results suggest that surface modification is effective for improving the comprehensive properties of Zn anode materials for Zn-air batteries.