Towards lithium-free solid-state batteries with nanoscale Ag/Cu sputtered bilayer electrodes

Enhancing the reversible Li growth efficiency in "Li-free" solid-state batteries is key for the deployment of this technology. Here, we demonstrate a nanoscale material design path that enables the reversible cycling of a lithium-free solid-state battery, using Li 7 La 3 Zr 2 O 12 (LLZO) electrolyte. By means of nanometric Ag-Cu bilayers, directly sputtered onto the LLZO, we can effectively control Li deposition. The robust thin film bilayer, which is compatible with LLZO, enables stable cycling, accommodating the volume changes without the need for extra external pressure. This work demonstrates the viability to design nanoscale bilayers that enable the efficient cycling of lithium-free solid-state batteries.