Lithium (Li) metal anodes have been considered as the “Holy Grail” for next-generation batteries due to their high theoretical capacity and low redox potential. However, nonuniform Li⁺ deposition leads to hazardous dendrite growth and poor electrochemical performance, which still severely hinders the practical applications of Li metal batteries. Herein, we propose a bifunctional composite separator to guide homogenous Li⁺ deposition, which smartly learns abundant experience from the dendrite-free design of solid-state batteries. A hierarchical porous composite solid-state electrolyte (CSE) consisting of polyvinylidene fluoride (PVDF) and Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) is coated on one side of polypropylene (PP) separator to fabricate the composite separator. The interactions between PVDF and LLZTO provide a three-dimensional fast Li⁺ channel along the PVDF, LLZTO, and PVDF/LLZTO interfaces, which can effectively redistribute uneven Li⁺ flux coming from the insulated PP separator. In addition, the CSE layer can further immobilize the anions, regulating a facile Li⁺ transport to evenly deposit on the Li anode. The synergetic effects between Li⁺ redistribution and anion immobilization result in higher Coulombic efficiency and enhanced cycling stability for Li metal batteries. This work presents fresh insights into CSE modified PP separator, which is an effective and simple solid-state-battery strategy for protected Li metal anodes and large-scale production.

锂（Li）金属阳极由于其高理论容量和低氧化还原电位而被认为是下一代电池的“圣杯”。然而，不均匀的Li ⁺沉积导致危险的枝晶生长和不良的电化学性能，这仍然严重阻碍了锂金属电池的实际应用。本文中，我们提出了一种双功能复合隔板来引导均匀的Li ⁺沉积，该隔板从固态电池的无枝晶设计中聪明地吸取了丰富的经验。由聚偏二氟乙烯（PVDF）和Li _6.4 La ₃ Zr _1.4 Ta _0.6 O ₁₂组成的分层多孔复合固态电解质（CSE）（LLZTO）涂覆在聚丙烯（PP）隔板的一侧，以制造复合隔板。PVDF和LLZTO之间的相互作用提供了沿着PVDF，LLZTO和PVDF / LLZTO界面的三维快速Li ⁺通道，可以有效地重新分配来自绝缘PP隔板的不均匀Li ⁺焊剂。另外，CSE层可以进一步固定阴离子，从而调节便捷的Li ⁺传输，使其均匀地沉积在Li阳极上。Li ⁺之间的协同作用重分布和阴离子固定化可提高锂金属电池的库仑效率并增强循环稳定性。这项工作为CSE改性PP隔膜提供了新的见解，这是一种有效且简单的固态电池策略，可用于受保护的Li金属阳极和大规模生产。