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 excel-lent 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 bat-tery 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.