Surface Control Behavior toward Crystal Regulation and Anticorrosion Capacity for Zinc Metal Anodes
Tingting Su, Ke Wang, Changyou Shao, Jiabo Le, Wenfeng Ren, Run‐Cang Sun
Abstract
The commercial application of high-safety aqueous zinc (Zn) secondary batteries is hindered by the poor cycling life of Zn metal anodes. Here we propose a dendrite growth and hydrogen evolution corrosion reaction mechanism from the binding energy of the deposited crystal plane on the Zn surface and the adsorption energy of H 2 O molecules on different crystal planes as well as the binding energy of H 2 O molecules with Zn 2+ ions. The biomass-based alkyl polyglucoside (APG) surfactant is adopted as an electrolyte additive of 0.15% to regulate the preferential growth of a parallel Zn(002) plane and enhance the anticorrosion ability of Zn metal anodes. The robust binding and adsorption energies of APG with Zn 2+ ions in the aqueous electrolyte and the Zn(002) plane on Zn surface generate a synergistic effect to increase the concentration of Zn 2+ ions on the APG-adsorbed Zn(002) plane, endowing the continuous growth of the preferential parallel Zn(002) plane and the excellent anticorrosion capacity. Accordingly, the long-term cycle stability of 4000 h can be achieved for Zn anodes with APG additives, which is better than that with pure ZnSO 4 electrolyte. With the addition of APG in the anolyte electrolyte, Zn-I 2 full cells display excellent cycling performance (70 mAh g –1 after 20000 cycles) as compared with that without APG additives.