Engineering the Structural Uniformity of Gel Polymer Electrolytes via Pattern-guided Alignment for Durable, Safe Solid-state Lithium Metal Batteries.

Ultrathin and super-toughness gel polymer electrolytes (GPEs) are the key enabling technology for durable, safe, and high-energy density solid-state lithium metal batteries (SSLMBs) but extremely challenging. However, GPEs with limited uniformity and continuity exhibit an uneven Li + flux distribution, leading to nonuniform deposition. Herein, a fiber patterning strategy for developing and engineering ultrathin (16 μm) fibrous GPEs with high ionic conductivity (∼ 0.4 mS cm -1 ) and superior mechanical toughness (∼ 613%) for durable and safe SSLMBs was proposed. The special patterned structure provides fast Li + transport channels and tailoring solvation structure of traditional LiPF 6 -based carbonate electrolyte, enabling rapid ionic transfer kinetics and uniform Li + flux, and boosting stability against Li anodes, thus realizing ultralong Li platting/stripping in the symmetrical cell over 3000 h at 1.0 mA cm -2 , 1.0 mAh cm -2 . Moreover, the SSLMBs with high LiFePO 4 loading of 10.58 mg cm -2 deliver ultralong stable cycling life over 1570 cycles at 1.0 C with 92.5% capacity retention and excellent rate capacity of 129.8 mAh g -1 at 5.0 C with a cut-off voltage of 4.2 V (100% DOD). Patterned GPEs systems are powerful strategies for producing durable and safe SSLMBs. This article is protected by copyright. All rights reserved.