Stabilizing Zinc Anode for High-Performance Aqueous Zinc Ion Batteries Via Employing a Novel Inositol Additive

Abstract

Here, a natural and non-toxic inositol additive with six hydroxyl groups is added into the 2 M ZnSO4 aqueous baseline electrolyte to enhance the electrochemical performances of the zinc ion batteries (ZIBs). 2H chemical shift in the Nuclear magnetic resonance demonstrates that the inositol molecule exhibits strongly coordinate with Zn2+ to change its solvation structure, which would significantly decrease the released water molecules number during the reduced deposition on Zn anode surface, hence effectively suppressing the HER, corrosion and by-product formation. Furthermore, the inositol molecules are more wettability to the zinc anode according to the density functional theory (DFT) calculations and the contact angle experimental results, which could restrict the two-dimensional diffusion of Zn2+, avoiding the agglomeration and zinc dendrite growth. As a result, the Zn||V2O5 employing the 2 M ZnSO4 aqueous electrolyte with 200 mM inositol additive presents a highest discharge specific capacity of 213 mAh g-1, and it still maintains a high reversible specific capacity of 99 mAh g-1 after 1800 cycles under the 1.0 A g-1 current density. The corresponding fundamental mechanism is deeply disclosed, which might devote guidance for solving the issues of ZIBs through electrolyte chemistries.

Keywords: Zinc ion battery, aqueous electrolyte, inositol additive, Zn anode, solvation structure