With the increasing demand for power batteries and energy storage devices, developing solid-state lithium metal batteries (LMBs) with high energy density and outstanding safety is urgent. Gel polymer electrolyte (GPE), a quasi-solid polymer electrolyte (SPE), is a currently promising electrolyte candidate for solid-state LMBs due to its outstanding performance. Herein, a solid-state LMB constructed with a GPE containing tetraethylene glycol dimethyl ether (G4) and succinonitrile (SN) is prepared, whose electrochemical performance is enhanced by synergistic enhancement effect of G4 and SN, and mechanical strength is reinforced by a PET nonwoven supporting layer. G2S2-GPE (a GPE contains the equal weight of G4 and SN) has a high room-temperature ionic conductivity of 0.90 mS cm−1 and Young's modulus of about 200 MPa, as well as enhanced thermal stability (decomposition temperature of 224 °C). Furthermore, the Li||LiFePO4 full battery can maintain 136.4 mAh g−1 high capacity with a 94.7 % capacity retention rate and 99.9 % average coulombic efficiency after 800 cycles at 0.5 C. Moreover, high voltage Li||LiNi0.6Co0.2Mn0.2O2 cell and Li||LiFePO4 pouch cell employing G2S2-GPE demonstrate satisfactory cycling and safety characteristics, indicating their potential for superior practicability. We believe popularizing this synergistic enhancement strategy in the electrolyte field is beneficial for developing high-performance LMBs.

中文翻译：

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PET无纺布增强锂金属电池用凝胶聚合物电解质中G4和SN的协同增强作用


随着对动力电池和储能器件的需求不断增加，开发具有高能量密度和出色安全性的固态锂金属电池 （LMB） 迫在眉睫。凝胶聚合物电解质 （GPE） 是一种准固体聚合物电解质 （SPE），由于其出色的性能，是目前很有前途的固态 LMB 电解质候选者。在此，制备了由含有四乙二醇二甲醚 （G4） 和琥珀腈 （SN） 的 GPE 构建的固态 LMB，其电化学性能通过 G4 和 SN 的协同增强作用得到增强，机械强度由 PET 无纺布支撑层增强。G2S2-GPE（包含等重量的 G4 和 SN 的 GPE）具有 0.90 mS cm-1 的高室温离子电导率和约 200 MPa 的杨氏模量，以及增强的热稳定性（分解温度为 224 °C）。此外，Li||LiFePO4 满电池在 0.5 C 下循环 800 次后，可保持 136.4 mAh g-1 的高容量，容量保持率为 94.7%，平均库仑效率为 99.9%。此外，高压 Li||LiNi0.6Co0.2Mn0.2O2 电池和 Li||采用 G2S2-GPE 的 LiFePO4 软包电池表现出令人满意的循环和安全特性，表明它们具有卓越的实用性潜力。我们相信，在电解质领域推广这种协同增强策略有利于开发高性能 LMB。