Synchronous Regulation of D–Band Centers in Zn Substrates and Weakening Pauli Repulsion of Zn Ions Using the Ascorbic Acid Additive for Reversible Zinc Anodes

Abstract

AbstractThe advanced aqueous zinc–ion batteries (AZIBs) are still challenging due to the harmful reactions including hydrogen evolution and corrosion. Here, a natural small molecule acid vitamin C (Vc) as an aqueous electrolyte additive has been selectively identified. The small molecule Vc can adjust the d band center of Zn substrate which fixes the active H+ so that the hydrogen evolution reaction (HER) is restrained. Simultaneously, it could also fine–tune the solvation structure of Zn ions due to the enhanced electrostatics and reduced Pauli repulsion verified by energy decomposition analysis (EDA). Hence, the cell retains an ultra–long cycle performance of over 1300 cycles and a superior Coulombic efficiency (CE) of 99.5 %. The prepared full cells display increased rate capability, cycle lifetime, and self–discharge suppression. Our results shed light on the mechanistic principle of electrolyte additives on the performance improvement of ZIBs, which is anticipated to render a new round of studies.