Engineering Chemo-Mechanical Properties of Zn Surfaces via Alucone Coating

TL;DR

This study uses first-principles simulations to evaluate how alucone coatings improve the chemical and mechanical stability of zinc surfaces, aiming to enhance zinc-ion battery performance.

Contribution

It provides a detailed first-principles analysis of alucone coatings on zinc surfaces, highlighting their strong cohesion and potential to improve stability in zinc-ion batteries.

Findings

Strong cohesive strength between alucone and Zn surfaces.

Favorable charge transfer at the interface.

Alucone coatings induce surface reconstruction and ductility.

Abstract

Aqueous zinc (Zn)-ion batteries (AZIB) are promising candidates for the next-generation 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.