Hydrogen/Electron Amphiphilic Bi‐Functional Water Molecular Inactivator‐Assisted Interface Stabilization in Highly Reversible Zn Metal Batteries

Abstract

Continuous hydrogen-bond-network in aqueous electrolytes can lead to uncontrollable hydrogen transfer, and combining the interfacial parasitic electron consumption cause the side reaction in aqueous zinc metal batteries (AZMBs). Herein, hydrogen/electron amphiphilic bi-functional 1,5-Pentanediol (PD) molecule was introduced to stabilize the electrode/electrolyte interface. Stronger proton affinity of -OH in PD can break bulk-H₂O hydrogen-bond-network to inhibit the activity of water, and electron affinity can enhance electron acceptation capability, which ensures that PD is preferentially bound to electrode material over H₂O. Besides, the participation of PD in the Zn²⁺ solvation structure reduces water content at the solid-liquid interface and promotes uniform deposition process by optimizing Zn²⁺ de-solvation energy. Accordingly, dense and vertical zinc texture based on intrinsic steric hindrance effect of PD and formed SEI protective layer to induce stable Zinc anode-electrolyte interface. Moreover, an organic-inorganic shielding water layer was formed at the cathode side to suppress vanadium dissolution in vanadium Oxide. Consequently, Zn//Zn symmetric cell could cycle for more than 5600 hours at 1 mAh cm^-2@1 mA cm^-2 (more than 250 hours at 50 °C). Besides, the VO₂ and I₂ cathode all achieved stable cycling performance and former pouch cell could reach average capacity of 0.13 Ah.