Correlating Nanoscale Structure with Electrochemical Property of Solid Electrolyte Interphases in Solid-State Battery Electrodes

TL;DR

This study links the nanoscale structure and composition of solid electrolyte interphases with electrochemical performance in solid-state batteries, revealing how morphology and chemical distribution influence efficiency.

Contribution

It introduces a method combining ESM and XPS to analyze the nanoscale morphology and composition of SEI layers and correlates these features with electrochemical performance.

Findings

Morphological variations affect Coulomb efficiency

Li and F distribution correlates with electrode performance

Optimal composite surface composition enhances battery efficiency

Abstract

Here, we correlate the nanoscale morphology and chemical composition of solid electrolyte interphases (SEI) with the electrochemical property of graphite-based composite electrodes. Using electrochemical strain microscopy (ESM) and X-ray photoelectron spectroscopy (XPS), changes of chemical composition and morphology (Li and F distribution) in SEI layers on the electrodes as a function of solid electrolyte contents are analyzed. As a result, we find a strong correlation between morphological variations on the electrode, Li and F distribution in SEI layer, and Coulomb efficiency. This correlation determines the optimum composition of the composite electrode surface that can maximize the physical and chemical uniformity of the solid electrolyte on the electrode, which is a key parameter to increase electrochemical performance in solid-state batteries.