Practical Challenges and Future Perspectives of All-Solid-State Lithium-Metal Batteries

The fundamental understandings and technological innovations in lithium-ion batteries are essential for delivering high energy density, stable cyclability, and cost-effective energy storages with the growing demands in the applications of electrical vehicles and smart grid. Solid-state electrolytes (SSEs) are more promising than organic liquid electrolyte in terms of excellent safety in developing lithium-metal anode as well as other high-capacity cathode chemistries, such as sulfur and oxygen. Considerable efforts have been made to give birth to the superionic conductors with ionic conductivities higher than 10(-3) S cm(-1) at room temperature. However, the high interfacial impedances from the poor compatibility of SSEs with electrodes limit their practical applications, which are discussed in this review. Furthermore, the recent advances and critical challenges for all-solid-state lithium-metal batteries based on the cathode materials of lithium-intercalation compounds, sulfur, and oxygen are overviewed, and their future developments are also prospected.