A flexible, ion-conducting solid electrolyte with vertically bicontinuous transfer channels toward high performance all-solid-state lithium batteries

All-solid-state lithium batteries, featuring high security and volume energy density, hold great potential as next-generation energy storage device. However, their development needs the fabrication of ionic conductive and structural stable solid electrolyte. Herein, Li 0.33 La 0.557 TiO 3 (LLTO) framework with interlocked porous structure is synthesized by sintering the gel permeated nylon. Then, poly(ethylene oxide) (PEO) is incorporated in the pores to produce PEO-LLTO framework solid electrolyte (PLLF electrolyte) with vertically bicontinuous phase. We demonstrate that LLTO framework fast transports Li + through the intrinsic vacancy; meanwhile the confined PEO with low crystallization displays fast Li + transfer ability, thus synergistically realizing efficient Li + conduction. This novel PLLF electrolyte exhibits a remarkable ionic conductivity of 2.04 × 10 −4 S cm −1 , which is ~72 times higher than that of traditional PEO-based electrolytes and superior to most reported solid electrolytes. Moreover, the interconnected networks endow PLLF electrolyte with excellent structural stability. Thus, the LiFePO 4 (LFP)/Li cell exhibits extraordinary cycling stability: the discharge capacity of 154.7 mAh g −1 at 1 C after 150 cycles with capacity decay of only 0.03% per cycle. Briefly, such a vertically bicontinuous phase structure maximizes the cooperation between the conduction function of ceramic framework and the stability of polymer, offering a promising approach for all-solid-state batteries.