Homogenizing Interfacial Stress by Nanoporous Metal Current Collector to Enable Stable All-Solid-State Li Metal Battery

Abstract

All-solid-state lithium-metal batteries are prone to shorting due to lithium penetration through the electrolyte layer. Li experiences creep during compression which creates stress in the electrolyte layer. Uneven deposition and stripping of Li further exaggerate the heterogeneity of stress distribution. To overcome this challenge, we design a current collector for Li metal. Its specific properties can homogenize interfacial stress distribution and prevent the solid electrolyte layer from developing additional defects that encourage penetration by Li metal during processes of fabrication and electrochemical cycling. Compared with a conventional current collector, our current collector effectively enhances the critical current density (1.7 vs. 0.5 mA/cm2) and extends cycle life (> 360 vs. 12 hours) for Li/Li symmetric cells. This development provides a chemistry-agnostic approach to improving the cycle life of solid-state Li batteries.