Massively Reconstructing Hydrogen Bonding Network and Coordination Structure Enabled by a Natural Multifunctional Co‐Solvent for Practical Aqueous Zn‐Ion Batteries

Abstract

The practical application of aqueous Zn-ion batteries (AZIBs) is hindered by the crazy Zn dendrites growth and the H₂O-induced side reactions, which rapidly consume the Zn anode and H₂O molecules, especially under the lean electrolyte and Zn anode. Herein, a natural disaccharide, d-trehalose (DT), is exploited as a novel multifunctional co-solvent to address the above issues. Molecular dynamics simulations and spectral characterizations demonstrate that DT with abundant polar -OH groups can form strong interactions with Zn²⁺ ions and H₂O molecules, and thus massively reconstruct the coordination structure of Zn²⁺ ions and the hydrogen bonding network of the electrolyte. Especially, the strong H-bonds between DT and H₂O molecules can not only effectively suppress the H₂O activity but also prevent the rearrangement of H₂O molecules at low temperature. Consequently, the AZIBs using DT30 electrolyte can show high cycling stability even under lean electrolyte (E/C ratio = 2.95 µL mAh^-1), low N/P ratio (3.4), and low temperature (-12 °C). As a proof-of-concept, a Zn||LiFePO₄ pack with LiFePO₄ loading as high as 506.49 mg can be achieved. Therefore, DT as an eco-friendly multifunctional co-solvent provides a sustainable and effective strategy for the practical application of AZIBs.