Oxygen-rich vacancy nickel–cobalt oxide cathode with low temperature adaptability for high-rate performance of alkaline zinc battery

Abstract

The study of alkaline zinc battery shows great prospects due to the advantages of high energy density, high safety and low cost. However, the traditional cathode materials exhibit slow ion transmission rate, poor electrochemical reversibility, and poor stability, especially in the low temperature environment. Herein, amorphous oxygen-rich vacancy nickel–cobalt-oxide nanomaterials (AM-Ov-NCO) with Co-MOF as a self-supporting template is synthesized as the cathode material for alkaline zinc-based batteries. Notably, the rich ion-diffusion channels of the amorphous compounds improve the electrochemical properties of the AM-Ov-NCO/NF electrodes. The metal–organic frame and rich oxygen vacancies promote the penetration of the electrolyte, effectively improve the conductivity of the material and the number of active sites, making the AM-Ov-NCO/NF electrode with good energy storage capacity. Aqueous alkaline zinc-based battery was assembled by coupling the AM-Ov-NCO/NF cathode with the Zn anode, the AM-Ov-NCO/NF//Zn full battery has excellent specific capacity (322.8 mAh g−1 at 1 A g−1) and extraordinary cycle durability (91.9% retained after 2000 cycles) with a maximum energy density of 539.08 Wh kg−1. Even in a low-temperatures of −25 °C, the AM-Ov-NCO/NF//Zn battery also maintains the 238.5 mAh g−1 at the current density of 1 A g−1. The research results provide a reasonable idea for the study of ultra-durable, low-temperature and high-performance nickel-zinc batteries.