Conventional lithium-ion batteries with liquid organic electrolytes generally suffer potential security risks concerning volatilization, flammability and explosion. Nonflammable and thin solid-state electrolytes particularly composite solid electrolytes (CSEs) that integrate the merits of different electrolyte systems have attracted increasing attention for advanced lithium batteries with improved energy density and high safety. In this work, a three-dimensional (3D) fiber-network-reinforced CSE, which consists of a mechanically robust, porous polyimide (PI) film as a host, Li_6.75La₃Zr_1.75Ta_0.25O₁₂ (LLZTO) nanoparticles and poly (vinylidene fluoride) (PVDF) polymer matrix with bis-trifluoromethanesulfonimide lithium salt as electrolyte filler, is designed and fabricated. Such unique 3D CSE films with PI fiber network holding for uniform dispersion of LLZTO in PVDF show continuous lithium ion transfer pathways and effective prevention for lithium dendrite growth, consequently exhibiting improved mechanical property (high tensile strength of 11.5 MPa) and high cyclic stability (more than 1000 h of cycling for Li symmetric batteries). Furthermore, solid-state LiNi_0.5Co_0.2Mn_0.3O₂/Li pouch cells with the PI-PVDF/LLZTO CSE exhibit excellent cyclic stability (152.6 mA h g^-1 with capacity retention of 94.9% at 0.1 C after 80 cycles) at room temperature, and high functionality and safety (withstand harsh environments such as folding, cutting and nail penetration) in practical applications.

具有液体有机电解质的常规锂离子电池通常遭受有关挥发，可燃性和爆炸的潜在安全风险。集成了不同电解质系统优点的不可燃，稀薄的固态电解质，尤其是复合固体电解质（CSE），对于具有改进的能量密度和高安全性的高级锂电池引起了越来越多的关注。在这项工作中，三维（3D）纤维网络增强的CSE由机械坚固的多孔聚酰亚胺（PI）膜作为主体，Li _6.75 La ₃ Zr _1.75 Ta _0.25 O _12组成设计并制备了以双三氟甲烷磺酰亚胺锂盐为电解质填料的（LLZTO）纳米粒子和聚偏氟乙烯（PVDF）聚合物基体。这种具有PI纤维网络的独特3D CSE膜可保持LLZTO在PVDF中的均匀分散，显示出连续的锂离子传递路径并有效防止了锂树枝状晶体的生长，因此具有改善的机械性能（11.5 MPa的高拉伸强度）和高循环稳定性（更多） Li对称电池的循环时间超过1000小时）。此外，具有PI-PVDF / LLZTO CSE的固态LiNi _0.5 Co _0.2 Mn _0.3 O ₂ / Li袋式电池表现出出色的循环稳定性（152.6 mA hg ^-1 在室温下，在0.1 C下80循环后的容量保持率为94.9％，在实际应用中具有很高的功能性和安全性（可承受苛刻的环境，例如折叠，切割和钉子穿透）。