Engineering the Structural Uniformity of Gel Polymer Electrolytes via Pattern‐Guided Alignment for Durable, Safe Solid‐State Lithium Metal Batteries

Abstract

AbstractUltrathin 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 is proposed. The special patterned structure provides fast Li+ transport channels and tailoring solvation structure of traditional LiPF6‐based carbonate electrolyte, enabling rapid ionic transfer kinetics and uniform Li+ flux, and boosting stability against Li anodes, thus realizing ultralong Li plating/stripping in the symmetrical cell over 3000 h at 1.0 mA cm−2, 1.0 mAh cm−2. Moreover, the SSLMBs with high LiFePO4 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% depth‐of‐discharge). Patterned GPEs systems are powerful strategies for producing durable and safe SSLMBs.