Engineering Chemo-Mechanical Properties of Zn Surfaces via Alucone Coating

Abstract

Aqueous zinc (Zn)-ion batteries (AZIB) are promising candidates for the nextgeneration energy store systems due to their high capacity and low cost. Despite their nominal performance, Zn anodes tend to rapidly develop dendrite and fracture, leading to substantial capacity loss and cycling stability failure. Well-controlled coating using organic-inorganic hybrid molecules is highly promising to substantially improve their chemo-mechanical stability without compromising their performance.We herein present a critical assessment of the chemical and mechanical stability of alucone-coated Zn surfaces using first-principles simulations. Negative adsorption energies indicate strong cohesive strengths between alucone and the selected Zn surfaces. Energetically favorable alucone coatings are further verified by charge transfer at interfaces as seen through Bader charge analysis. Negative surface stress profiles at alucone coated interface are mostly responsible for surface reconstruction.The contributions of surface elastic constants are dependent on the selection of slip planes and the thickness of the thin film. By considering plane stress conditions, we calculate the mechanical properties which indicate the ductility of the alucone-coated basal thin film. I. INTRODUCTIONFossil-fuel consumption in transportation technologies is the second largest source of CO 2 emission, and expected to increase by 28% by 2040 [1]. Greener energy applications highly depends on the development of well-performing, reliable, and cost-effective energy storage systems such as batteries, fuel cell, and supercapacitors [2][3][4]. Regardless of any battery design, electrodes are the main components that determine the bottleneck of battery capacity, power output, cyclic stability, and lifetimes of energy storage systems [5,6]. Thus,