Lithium dendrites in all-solid-state batteries: From formation to suppression

All-solid-state lithium (Li) metal batteries combine high power density with robust security, making them one of the strong competitors for the next generation of battery technology. By replacing the flammable and volatile electrolytes commonly found in traditional Li-ion batteries (LIBs) with noncombustible solid-state electrolytes (SSEs), we have the potential to fundamentally enhance safety measures. Concurrently, SSE would be capable of fitting high specific capacity (3860 mAh g⁻¹) metal Li and is expected to break through the upper limit of mass-energy density (350 Wh kg⁻¹) of existing LIBs system. Nevertheless, the growth of Li dendrites on the negative side or the nucleation of Li inside SSEs may give rise to battery short circuits, which is the primary factor limiting the application of Li metal. Recognizing this, the focus of this review is to provide a perspective for experimentalists and theorists who closely monitor various surface/interface and microstructure phenomena to understand Li dendrites. The strategies to reveal the complicated deposition mechanism and to control the dendrite growth of metal Li in solid-state batteries, as well as the advanced characterization methods of metal Li, provide suggestions for the practical research of solid-state Li metal batteries.