Research and Development of Solid-State Batteries and its Application

Abstract

The overconsumption of fossil fuels has led to energy and environmental crises, making the development of safe and efficient energy storage systems a key research focus. Lithium-ion batteries are widely applied due to their high energy density, yet conventional liquid electrolytes suffer from flammability and leakage issues. All-solid-state lithium batteries (ASSBs), which replace liquid electrolytes with solid counterparts, exhibit superior safety and potential for next-generation applications. This review summarizes the characteristics and advances of oxide, sulfide, and polymer solid electrolytes, with comparative analysis of thermal stability, ionic conductivity, interfacial resistance, and mechanical strength. Results indicate that sulfide electrolytes achieve the highest conductivity but poor stability; oxide electrolytes offer excellent safety yet rigid interfacial contact; polymer electrolytes provide outstanding flexibility and processability but limited room-temperature conductivity. Composite electrolytes, through complementary effects, show promise in enhancing interfacial stability and overall performance. Moreover, industrial efforts by Toyota, Volkswagen, and Solid Power highlight accelerating commercialization. In conclusion, despite challenges in interface control, ion transport, and scalable fabrication, solid-state batteries are expected to achieve breakthroughs and drive the future development of electric vehicles.