Delicate design of lithium‐ion bridges in hybrid solid electrolyte for wide‐temperature adaptive solid‐state lithium metal batteries

Abstract Hybrid solid electrolytes have emerged as promising candidates for next‐generation high‐energy‐density solid‐state lithium metal batteries owing to the enhanced safety and processability. Nevertheless, the practical implementation remains hindered by severe interfacial Li + transport barriers at ceramic‐polymer junctions, particularly under ambient low‐temperature or high‐power‐density surroundings. Herein, the lithium‐ion bridge concept has been proposed to accelerate Li + transport kinetics across the ceramic‐polymer interphase through the delicate design of a chemical bonding strategy. As demonstrated, the poly(vinylidene fluoride‐co‐hexafluoropropylene) (PH) chain with Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) particles can be connected by lithium benzene sulfonate as Li + conductive bridges. With these Li + bridges, this unique hybrid PH‐LLZTO solid‐state electrolyte exhibits an exceptional ionic conductivity of 0.71 mS cm −1 at 25°C with a superior Li + transference number of 0.67. Impressively, this advanced solid‐state electrolyte empowers high‐voltage LiNi 0.8 Co 0.1 Mn 0.1 O 2 /Li cells under fast charge/discharge capability as high as 4C and a wide temperature range from −20°C to 60°C. Consequently, the optimal solid‐state Li metal battery could stabilize at −20°C with a high discharge specific capacity of 130 mAh g −1 . Moreover, a bipolar pouch cell by stacking 4 units can be successfully assembled using this advanced solid‐state electrolyte with fast Li + transport kinetics and delivers an ultra‐high voltage of 15.12 V, showcasing the great potential of integrated module application in the future. image