Nanocomposite Design for Solid-State Lithium Metal Batteries: Progress, Challenge, and Prospects

Lithium metal batteries have gained significant attention due to their high energy density, making them a promising candidate for various applications, including electric vehicles and grid-scale energy storage. Nevertheless, the practical development of lithium metal batteries faces challenges related to dendrite formation, low cycling efficiency, and poor safety due to the use of liquid electrolytes. Solid-state electrolytes (SSEs) are the most attractive alternatives for next-generation safe and high-energy density energy storage systems. However, conventional SSEs fail to meet the simultaneous demands of high ionic conductivity and mechanical properties, due to their intrinsic solid-state chemical properties. Among numerous modifying strategies for SSE chemistry, composite polymer electrolytes (CPEs) with advanced nanocomposite design display suitable processability, wettability, high flexibility, low density, and low cost of production. This review comprehensively outlines the merits and functions of advanced nanocomposite designs in CPEs. This review provides valuable insights into the recent progress in nanocomposite designs of solid-state electrolytes, offering guidance for future research and development efforts in this field.