Safety issues (e.g., burn and aerogenesis) triggered by flammable liquid electrolyte (LE) have impeded the large-scale applications of lithium metal batteries (LMBs). It is of great importance to introduce flame-retardant constituent into LMBs system to alleviate above problems. Succinonitrile (SN) is ideally suited for application as a flame-retardant additive due to the merits of excellent thermal stability and high dielectric constant. However, the severe parasitic reactions with Li anode restrict the extensive application of SN. Herein, an in-situ polymerized gel electrolyte consisting of fumaronitrile (FN), methyl methacrylate (MMA) and ethoxylated trimethylolpropane triacrylate (ETPTA) is prepared. FN segment is fixed in polymer chains and shows the similar molecular structure with SN after polymerization, therefore the flame retardant effect is achieved and the parasitic reaction with Li anode is suppressed. Furthermore, the cross-linked structure contributed by ETPTA plays an important role in strengthening electrochemical performance of fumaronitrile based gel polymer electrolyte (FGPE) by inhibiting the growth of lithium dendrites and promoting the transfer of Li ions. Li/FGPE/Li symmetrical cell exhibits a great performance with the maximum voltage of about 11 mV after 7850 h, while a high reversible capacity of 147.6 mAh g⁻¹ is maintained after 1000 cycles for LiFePO₄/FGPE/Li battery.

由易燃液体电解质（LE）引发的安全问题（例如，燃烧和产气）阻碍了锂金属电池（LMB）的大规模应用。在LMBs体系中引入阻燃成分对于缓解上述问题具有重要意义。由于出色的热稳定性和高介电常数的优点，琥珀腈 (SN) 非常适合用作阻燃添加剂。然而，锂负极严重的寄生反应限制了SN的广泛应用。在此，原位制备了由富马腈（FN）、甲基丙烯酸甲酯（MMA）和乙氧基化三羟甲基丙烷三丙烯酸酯（ETPTA）组成的聚合凝胶电解质。FN链段固定在聚合物链中，聚合后呈现出与SN相似的分子结构，从而达到阻燃效果，抑制与锂负极的寄生反应。此外，ETPTA贡献的交联结构通过抑制锂枝晶的生长和促进锂离子的转移，在增强富马腈基凝胶聚合物电解质（FGPE）的电化学性能方面发挥着重要作用。Li/FGPE/Li对称电池表现出良好的性能，7850 h后最大电压约为11 mV，同时具有147.6 mAh g ^-1的高可逆容量LiFePO ₄ /FGPE/Li 电池在 1000 次循环后保持不变。