Multifunctional zinc-nickel alloy enabling high-performance aqueous zinc ion batteries

Abstract

Aqueous zinc ion batteries are considered to be the new type of secondary batteries that have the potential to replace lithium-ion batteries as the most widely used in the future due to their green environment, high specific capacity and abundant zinc resources. However, due to the contact between the zinc anode and electrolyte, the generation of by-products and corrosion phenomena are not completely avoided, which can easily lead to problems such as short cycle life and poor electrochemical performance of the battery. In this study, uniform zinc-nickel alloy (ZnNi) was prepared by melting method. The element nickel has excellent corrosion resistance and is widely used to improve the corrosion resistance of metal alloys, so the introduction of nickel effectively enhances the corrosion resistance of ZnNi alloys. In addition, metallic nickel shows strong attraction to Zn2+, which can promote the uniform distribution and deposition of Zn2+ and inhibit the dendrites growth to prolong the battery life. Notably, the ZnNi-assembled symmetric cell exhibited excellent cycling performance compared with the Zn//Zn cell (100 h), with a cycle life of up to 1000 h at 2 mA cm−2. In addition, the capacity retention rate of the ZnNi//MnO2 full cell was still as high as 90.6 % after 1000 cycles. The preparation of the ZnNi alloy anode may provide a new idea for future alloying strategies.