Effects of Electrolyte Additives on the Properties of Zinc-Bismuth Electrodes in Zinc-Air Batteries

Abstract

With the aim of developing zinc-air batteries with a large capacity and long life, submicron ultrafine zinc-bismuth powders with a high surface area, high activity and low cost were prepared by a DC arc evaporation method. To reduce the corrosion rate of zinc-air batteries composed of ultrafine zinc-bismuth powders and to improve the charge and discharge performance of the zinc electrode, organic additives such as benzotriazole (BTA), thiourea (CH4N2S) and sodium dodecyl benzene sulfonate (SDBS) were added individually into the electrolyte. The hydrogen evolution rate of the zinc electrode composed of zinc-bismuth powders and the properties of zinc-air batteries were investigated by hydrogen evolution experiments and electrochemical tests. The adsorption mechanism of different electrolyte additives on the zinc electrode was studied based on SEM, Raman spectroscopy and electrochemical tests. The corrosion performance of BTA was the best of the single electrolyte additives. The charge-discharge performance and cycle performance of the zinc-air battery were greatly improved, and the corrosion inhibition efficiency of the zinc electrode was 76.9%. The capacity after 60 cycles was 458.2 mAh/g, and the capacity retention rate was 91%. Of the two-element compound electrolyte additives, the combination of BTA and SDBS was the best; the optimum corrosion inhibition efficiency of the zinc electrode was 88.5%, the capacity was 497.0 mAh/g after 60 cycles, and the capacity retention rate was 96%.