Fatigue of Li metal anode in solid-state batteries.

Abstract

Solid-state lithium metal batteries (SSBs) are promising for electric vehicles because of their potential to provide high energy density and enhanced safety. However, these batteries face short-circuit challenges caused by uncontrolled lithium dendrite growth during cycling. Using operando scanning electron microscopy and phase-field simulations, we determined that failure of SSBs is closely linked to the fatigue of the lithium metal anode, which markedly contributes to interface degradation and dendrite growth in SSBs. This fatigue follows the Coffin-Manson equation in mechanics, indicating that it is an innate characteristic. Clarifying the essential role of fatigue provides a physical basis for understanding failures of SSBs and paves the way to extending their lifespan.