Ultrathin Electrolyte Membranes With Reinforced Concrete Structure for Fast‐Charging Solid‐State Lithium Metal Batteries

Abstract Realizing solid‐state lithium (Li) metal batteries with fast charging capability and desirable energy density remains a key challenge for emerging applications for drones and consumer electronics, which require solid electrolytes to maintain good ionic conductivity and mechanical integrity with fast reaction kinetics. Herein, an 8.4 µm ultrathin solid electrolyte membrane is manifested with a reinforced concrete structure and expedited ion hopping migration capability, enabling the solid‐state battery with fast charging capability. The rapid multi‐dimensional Li‐ion transportation network is well‐constructed based on nanosized ceramic conductor aggregation and polymer chain induction, which allows homogenized Li⁺ distribution on the interface with a continuous uniform and steady plating/stripping process, thereby enhancing interfacial stability and inhibiting dendrite growth. Attributed to its structural superiorities, the assembled solid‐state lithium metal battery maintains an excellent capacity retention rate of 89.2% after 1300 cycles at 10 C. A 1.2 Ah pouch cell is fabricated with a high energy density of 415.2 Wh kg⁻¹ and also capable of cycling at 5 C, showing great potential for the practical application of solid‐state batteries for next‐generation energy storage devices.