High-voltage Solid-State Lithium Batteries: A Review of Electrolyte Design, Interface Engineering, and Future Perspectives

Solid-state lithium batteries have become a research hotspot in the field of large-scale energy storage due to their excellent safety performance. The development of high-voltage positive electrode materials matched with lithium metal anode have advanced the energy density of solid-state lithium batteries close to or even exceeding that of lithium batteries based on a liquid electrolyte, which is expected to be commercialized in the future. However, in high voltage conditions (> 4.3 V), the decomposition of electrolyte components, structural degradation, and interface side reactions significantly reduce battery performance and hinder its further development. This review summarizes the latest research progress of inorganic electrolytes, polymer electrolytes, and composite electrolytes in high-voltage solid-state lithium batteries. At the same time, the designs of high-voltage polymer gel electrolyte and high-voltage quasi solid-state electrolyte are introduced in detail. In addition, interface engineering is crucial for improving the overall performance of high-voltage solid-state batteries. Finally, we highlight the challenges faced by high-voltage solid-state lithium batteries and put forward our own views on future research directions. This review offers instructive insights into the advancement of high-voltage solid-state lithium batteries for large-scale energy storage applications.