Recent Advances in Stability Issues of Inorganic Solid Electrolytes and Composite Solid Electrolytes for All‐Solid‐State Batteries

Abstract The development of solid‐state batteries has become one of the most promising directions in rechargeable secondary batteries due to their considerable energy densities and favorable safety. However, solid‐state batteries with higher energy density and more durable and stable cycle life should be developed for large‐scale energy storage and adaption to the rapidly increasing lithium battery production and sales market. Although inorganic solid electrolytes (ISEs) and composite solid electrolytes (CSEs) are relatively advantageous solid‐state electrolytes, they also face severe challenges. This review summarizes the main stability issues related to chemical, mechanical, thermal, and electrochemical aspects faced by ISEs and CSEs. The corresponding state‐of‐the‐art improvement strategies have been proposed, including filling of modified particles, electrolyte pore adjustment, electrolyte internal structure arrangement, and interface modification.