Core Insights - The solid-state battery industry is exploring multiple technical routes, including oxide, sulfide, polymer, and halide, but each route faces significant challenges [2][3][4][5] - A new trend is emerging where researchers are combining different routes to leverage their strengths and mitigate weaknesses, leading to the development of composite routes [5][6][7] Group 1: Technical Challenges - Each technical route has its own "roadblocks," with oxides facing issues related to contact resistance and lithium stability, while sulfides struggle with stability and reactivity with moisture [3][4] - The cost of sulfide solid electrolytes is high, and their corrosive nature requires expensive production equipment, making commercial viability challenging [4][9] - The polymer route offers good interface contact but has issues with conductivity and stability, while halides also face challenges in electrochemical stability and processing [4] Group 2: Composite Route Development - The integration of different materials is seen as a necessary step for improving electrolyte performance, with researchers advocating for a balanced approach that combines the strengths of various routes [5][6] - Composite routes have shown promising results, such as improved ionic conductivity and high-rate performance at elevated temperatures [6][7] - Companies are increasingly adopting composite technologies, with significant advancements in solid-state battery performance being reported [7][8] Group 3: Market and Economic Considerations - The current market prices for sulfide electrolytes are significantly higher than traditional lithium iron phosphate, making it difficult for solid-state batteries to compete economically [9][10] - Companies are targeting substantial cost reductions for solid-state battery cells by 2025 and beyond, focusing on raw material cost reduction, process improvements, and economies of scale [9][10] - The solid-liquid hybrid semi-solid state battery is expected to remain a viable option for a long time due to the challenges in achieving cost-effective solid-state batteries [8][10]