Interfacial Atomistic Mechanisms of Lithium Metal Stripping and Plating in Solid-State Batteries

All-solid-state batteries based on a Li metal anode represent a promising next-generation energy storage system, but are currently limited by low current density and short cycle life. Further research to improve the Li metal anode is impeded by the lack of understanding in its failure mechanisms at lithium-solid interfaces, in particular, the fundamental atomistic processes responsible for interface failure. Here, using large-scale molecular dynamics simulations, the first atomistic modeling study of lithium stripping and plating on a solid electrolyte is performed by explicitly considering key fundamental atomistic processes and interface atomistic structures. In the simulations, the interface failure initiated with the formation of nano-sized pores, and how interface structures, lithium diffusion, adhesion energy, and applied pressure affect interface failure during Li cycling are observed. By systematically varying the parameters of solid-state lithium cells in the simulations, the parameter space of applied pressures and interfacial adhesion energies that inhibit interface failure during cycling are mapped to guide selection of solid-state cells. This study establishes the atomistic modeling for Li stripping and plating, and predicts optimal solid interfaces and new strategies for the future research and development of solid-state Li-metal batteries.

Automated summary

This study conducts atomistic modeling for lithium stripping and plating on solid electrolytes, observing the initiation of interface failure with the formation of nano-sized pores, and the effects of interface structures, lithium diffusion, adhesion energy, and applied pressure on interface failure during lithium cycling. The simulations map the parameter space of applied pressures and interfacial adhesion energies that inhibit interface failure, providing guidance for the selection of solid-state cells and predicting optimal solid interfaces for future research and development of solid-state Li-metal batteries.