The poor interfacial contact and notorious instability issues between solid electrolyte and electrodes seriously handicap the practical applications of solid-state lithium metal batteries (LMBs). In-situ polymerization is a considerable choice to upgrade the interfacial transport properties by directly curing the liquid precursor inside the cell. Herein, a ∼ 17 μm poly(ethylene glycol) methyl ether methacrylate (PEGMEA) based solid polymer electrolyte (SPE) is prepared by this method. Trimethyl phosphate (TMP) and LiNO₃ are introduced to promote the ion transport as well as enhance the electrodes/electrolyte interfacial stability. Interestingly, although LiNO₃ increases the electrolyte’s glass transition temperature thus hinders the anion transport, while higher Li⁺ conductivity is obtained due to the weakened interaction between Li⁺ and its ligands, ethylene oxide (EO) and TMP. The optimal electrolyte (PTLiN1) shows an acceptable ionic conductivity of 1.2 ×10^-4 S cm^-1 at 55°C and lithium ion transference number (${\mathrm{t}}_{{\mathrm{L}\mathrm{i}}^{+}}$) of 0.46, which enables the Li||Li symmetric cells to run stability within 1500 h (0.2 mA cm^-2, 0.4 mAh cm^-2) at 55°C and 1000 h (0.1 mA cm^-2, 0.2 mAh cm^-2) at 25°C. Meanwhile, the LiFePO₄||Li cell with PTLiN1 shows superior long cycle lifetime with a high capacity retention of 88.4% over 300 cycle at 0.5 C. The cells coupled with LiCoO₂ can even work stably under room temperature in the voltage range of 3.0 ∼ 4.3 V. Pouch cells based on PTLiN1 are also prepared and show outstanding flexibility and high security, which provides new idea for the development of economical and convenient solid-state batteries.

固体电解质和电极之间不良的界面接触和臭名昭著的不稳定性问题严重阻碍了固态锂金属电池（LMB）的实际应用。原位聚合是通过直接固化电池内的液体前体来提升界面传输性能的一个重要选择。在此，通过该方法制备了约 17 μm 的聚（乙二醇）甲基醚甲基丙烯酸酯（PEGMEA）基固体聚合物电解质（SPE）。引入磷酸三甲酯 (TMP) 和 LiNO ₃以促进离子传输以及增强电极/电解质的界面稳定性。有趣的是，尽管 LiNO ₃提高了电解质的玻璃化转变温度，从而阻碍了阴离子的传输，而较高的 Li ^{+由于Li +}与其配体环氧乙烷（EO）和TMP之间的相互作用减弱，因此获得了导电性。最佳电解质 (PTLiN1)在 55 ^° C和锂离子迁移数⁽${\mathrm{吨}}_{{\mathrm{大号}\mathrm{一世}}^{+}}$) 为 0.46，这使得 Li||Li 对称电池在 55°C 和 1000 小时^（ 0.1 mA cm ^{-2 ,} 0.2 mAh cm ^{- 2} ) 在 25°C。同时，采用 PTLiN1 的 LiFePO ₄ ||Li 电池表现出优异的长循环寿命，在 0.5 C 下 300 次循环后容量保持率高达 88.4%。与 LiCoO ₂结合的电池甚至可以在室温下在 3.0 的电压范围内稳定工作∼ 4.3 V. 还制备了基于PTLiN1的软包电池，表现出优异的柔韧性和高安全性，为开发经济、便捷的固态电池提供了新思路。