Interfacial H-bond Network/Concentration Fields/Electric Fields Regulation Achieved by D-Valine Anions Realizes the Highly Efficient Aqueous Zinc Ion Batteries

Abstract

Uncontrolled mobile anions and proton transport result in many issues, including interfacial anion depletion, irregular multiphysics fields fluctuations, space charge layer-induced interfacial Zn dendrites, and hydrogen evolution reaction (HER), which seriously exacerbates the cycling stability of zinc-ion batteries. Herein, this work constructs an efficient D-valine anion interface structure to reversely regulate the Zn²⁺/H⁺ dynamic chemistry and unlocks the multiple regulation effects of this anionic interface by investigating interfacial proton transport and complex concentration/electric fields distribution of Zn anode through dynamic in-situ spectroscopy analysis, static energy calculations, and molecular dynamics simulation. We unravel core factors affecting complicated interfacial HER processes and the generation of the space charge layer. This anionic interfacial layer severs proton hopping transport by rupturing the initial water–water hydrogen bond, which effectively restrains uncontrolled HER processes. Further, the anion-immobilized interfacial layer accelerates Zn²⁺ transfer to optimize the interfacial concentration fields. Also, the anionic interface restrains the formation of the anion depletion layer by relieving rapid Zn²⁺ ions exhaustion and strengthening the uniformity of interfacial electrical field distribution, which suppresses space charges-induced Zn dendrite growth. Consequently, Zn||Zn symmetric cells deliver an ultralong cycle life of 4150 h. Importantly, the multiple regulation effects enable Zn||I₂ cells exhibit long-term stable life.