Samsung Advanced Institute of Technology

Lithium metal batteries (LMBs) are considered the most promising next-generation battery system because of their high energy density and safety. Significant research effort has been devoted to developing more stable and energy-dense LMBs than the state-of-the-art Li-ion batteries. However, the LMB performance remains unsatisfactory for commercialization, primarily owing to the inability of solid electrolytes to block Li dendrite propagation. Herein, we demonstrate highly stable LMB employing garnet-type oxide electrolyte by introducing a carbon-based interlayer with careful interface engineering. We theoretically and experimentally demonstrate that our design effectively regulated Li deposition away from the solid electrolyte, preventing dendrite penetration. We further demonstrated that the interface condition between the interlayer and solid electrolyte is critical and present an effective strategy to achieve an optimal interface. Overall, our garnet-type oxide-based LMB exhibited a high energy density of ~680 Wh/L for over 800 cycles at room temperature without using external pressure.