A High-Performance Carbonate-Free Lithium|Garnet Interface Enabled by a Trace Amount of Sodium.

Garnet-type solid-state electrolytes (SSEs) are promising for the realization of next-generation high-energy-density Li metal batteries. However, a critical issue associated with the garnet electrolytes is the poor physical contact between the Li anode and the garnet SSE and the resultant high interfacial resistance. Here, it is reported that the Li|garnet interface challenge can be addressed by using Li metal doped with 0.