Liquid leakage and lithium dendrite growth are common safety hazards of lithium-ion batteries, and the application of quasi-solid electrolytes are considered to be the most promising material for inhibiting the safety problems. Herein, a new type of bi-functional ionic liquid is synthesized and polymerized into double cross-linked poly(ionic liquid) electrolyte (denoted as PIL-PEI) by dual cross-linking method [ring-opening polymerization network: epoxy groups in 1-vinyl-3-epoxypropylimidazolium bis(trifluoromethanesulfonyl)imide (VEIM-TFSI) cross-linked with amino-groups in poly(ethylene imine) (PEI), radical cross-linking network: VEIM-TFSI cross-linked with poly(ethylene glycol) diacrylate (PEGDA)]. The Double cross-linked network of PIL-PEI reveals satisfactory flexibility, thermal stability and remarkable electrochemical performances (room-temperature ionic conductivity, 1.03×10^-3 S cm⁻¹ and lithium-ion transference number, 0.47). Furthermore, the compact network of PIL-PEI enables the formation of a strong solid electrolyte interface (SEI) layer on the lithium metal leading to the inhibition of lithium dendrite growth. As results, the batteries electrochemical performances, such as high charge-discharge capacity (165.6 mAh g^-1), robust rate behavior (5.0C for 94 mAh g^-1) and long-term lifespan (97.8% coulomb efficiency after 200 cycles) are significantly improved after assembled by LiFePO₄-based cells equipping PIL-PEI as electrolyte. The soft package cell assembled with PIL-PEI is able to successfully light up the LED light and keep illuminating under varying hazardous situations such as bending and cutting, indicating that the PIL-PEI will have potential application value in highly secure flexible electronic devices.

漏液和锂枝晶生长是锂离子电池常见的安全隐患，准固体电解质的应用被认为是抑制安全问题的最有希望的材料。在此，通过双交联法[开环聚合网络：1中的环氧基团]，合成新型的双功能离子液体并聚合成双交联的聚离子液体电解质（表示为PIL-PEI）。 -乙烯基-3-环氧丙基咪唑双（三氟甲磺酰基）酰亚胺（VEIM-TFSI）与聚（乙烯亚胺）（PEI）中的氨基交联，自由基交联网络：VEIM-TFSI与聚乙二醇交联）二丙烯酸酯（PEGDA）]。PIL-PEI的双重交联网络显示出令人满意的灵活性，^-3 S cm ^-1和锂离子转移数，0.47）。此外，PIL-PEI的紧凑网络可在锂金属上形成牢固的固体电解质界面（SEI）层，从而抑制了锂枝晶的生长。结果，电池的电化学性能，例如高充放电容量（165.6 mAh g ^-1），稳健的速率行为（94 mAh g ^-1为5.0C ）和长期寿命（200次循环后库仑效率为97.8％）由LiFePO ₄组装后得到显着改善电池，配备PIL-PEI作为电解质。与PIL-PEI组装在一起的软包装电池能够成功点亮LED灯，并在弯曲和切割等各种危险情况下保持照明，这表明PIL-PEI在高度安全的柔性电子设备中具有潜在的应用价值。