Steric‐hindrance Effect Tuned Ion Solvation Enabling High Performance Aqueous Zinc Ion Batteries

Abstract

AbstractDespite many additives have been reported for aqueous zinc ion batteries, steric‐hindrance effect of additives and its correlation with Zn2+ solvation structure have been rarely reported. Herein, large‐sized sucrose biomolecule is selected as a paradigm additive, and steric‐hindrance electrolytes (STEs) are developed to investigate the steric‐hindrance effect for solvation structure regulation. Sucrose molecules do not participate in Zn2+ solvation shell, but significantly homogenize the distribution of solvated Zn2+ and enlarge Zn2+ solvation shell with weakened Zn2+−H2O interaction due to the steric‐hindrance effect. More importantly, STEs afford the water‐shielding electric double layer and in situ construct the organic and inorganic hybrid solid electrolyte interface, which effectively boost Zn anode reversibility. Remarkably, Zn//NVO battery presents high capacity of 3.9 mAh ⋅ cm−2 with long cycling stability for over 650 cycles at lean electrolyte of 4.5 μL ⋅ mg−1 and low N/P ratio of 1.5, and the stable operation at wide temperature (−20 °C~+40 °C).