Toward the Scale‐Up of Solid‐State Lithium Metal Batteries: The Gaps between Lab‐Level Cells and Practical Large‐Format Batteries

Abstract The scale‐up process of solid‐state lithium metal batteries is of great importance in the context of improving the safety and energy density of battery systems. Replacing the conventional organic liquid electrolytes (OLEs) with solid‐state electrolytes (SSEs) opens a new path for addressing increasing energy demands. Advanced approaches have been validated in lab‐scale cells, but only a few successful results can be applied on the practical scale. Herein, the battery systems enabled by SSEs are briefly reviewed and the difficulties and challenges for both lab‐level cells and large‐scale batteries from the perspective of SSEs, cathodes, anodes, and battery configurations, are described. On this foundation, promising opportunities to eliminate problems are also summarized and evaluated. The key gaps between lab‐level cells and practical batteries in the integral technology chains including electrolyte preparation, layer fabrication, cell design, and assembly processes are then identified. Finally, feasible future strategies are summarized and possible development directions are described, which will provide guidance for follow‐up research.