The work entitled "An Overcrowded Water-Ion Solvation Structure for Robust Anode Interphase in Aqueous Lithium-Ion Batteries" is published online. Check out the following link for the full text.

https://pubs.acs.org/doi/10.1021/acsami.1c15742

This study reports a long-awaited electrolyte design of overcrowded aqueous electrolyte, filling the blank in the field of high-voltage aqueous batteries.In recent years, water-in-salt (WIS) electrolytes have drawn immense research attentions in various battery systems, including aqueous Li-ion, aqueous Na-ion, aqueous K-ion aqueous Zn batteries, etc. Because of intimate interactions between cation and anion, WIS electrolyte induces the formation of anion-derived solid electrolyte interphase (SEI) and expands the aqueous electrolyte voltage window to > 3.0 volts. Previous studies mainly focus on further increasing the total salt concentration (21 m~63 m), but the effect is limited and artificial coating layers are usually added to stabilize the anode. Here, we seek a new approach of designing an overcrowded solvation structure to further intensify ion-solvent interactions in aqueous batteries by adding a novel shielding agent (1,4-dioxane, DX). Owing to its hydrogen bonding ability, DX perfectly solves the long-standing dilemma of miscibility with H₂O and retaining H₂O-ion solvation structure. As a result, the anion reaction chemistry on the anode surface could be enhanced to a level unattainable in WIS electrolytes. With a robust SEI with unprecedented LiF presence and a wide electrolyte operation window of 3.7 V, the Li₄Ti₅O₁₂/LiMn₂O₄ full cell demonstrates outstanding performance compared to other aqueous batteries, despite of a very low salt concentration (<2 m). 

Thanks for Qingshun's creative work and great efforts, as well as kind help from all collaborators!