Abstract：
The utilization of solid polymer electrolytes (SPEs) in all-solid-state sodium metal batteries has been extensively explored due to their excellent flexibility, processability adaptability to match roll-to-roll manufacturing processes, and good interfacial contact with a high-capacity Na anode; however, SPEs are still impeded by their inadequate mechanical strength, excessive thickness, and poor stability with Na anodes. Herein, a robust, thin, and cost-effective polyethylene (PE) film is employed as a skeleton for infiltrating poly(ethylene oxide)-sodium bis(trifluoromethanesulfonyl)imide (PEO/NaTFSI) to fabricate PE-PEO/NaTFSI SPE. The resulting SPE features a remarkable thickness of 25 μm, lightweight property (2.1 mg cm-2), superior mechanical strength (tensile strength = 100.3 MPa), and good flexibility. The SPE also shows an ionic conductivity of 9.4 × 10-5 S cm-1 at 60 °C and enhanced interfacial stability with a sodium metal anode. Benefiting from these advantages, the assembled Na-Na symmetric cells with PE-PEO/NaTFSI show a high critical current density (1 mA cm-2) and excellent long-term cycling stability (3000 h at 0.3 mA cm-2). The all-solid-state Na||PE-PEO/NaTFSI||Na3V2(PO4)3 coin cells exhibit a superior cycling performance, retaining 93% of the initial capacity for 190 cycles when matched with a 6 mg cm-2 cathode loading. Meanwhile, the pouch cell can work stably after abuse testing, proving its flexibility and safety. This work offers a promising strategy to simultaneously achieve thin, high-strength, and safe solid-state electrolytes for all-solid-state sodium metal batteries.
摘要：
固体聚合物电解质（SPE）在全固态钠金属电池中的利用由于其优异的灵活性而得到了广泛的探索，可加工性适应性，以匹配卷对卷制造工艺，与高容量Na阳极的良好界面接触；然而，SPE仍然受到机械强度不足的阻碍，厚度过大,Na阳极稳定性差。在这里，一个健壮的，薄,和成本有效的聚乙烯（PE）膜用作渗入聚（环氧乙烷）-双（三氟甲磺酰基）酰亚胺钠（PEO/NaTFSI）的骨架，以制造PE-PEO/NaTFSISPE。所得的SPE具有25μm的显着厚度，轻质性能（2.1mgcm-2），优越的机械强度（抗拉强度=100.3MPa），和良好的灵活性。SPE在60°C下还显示出9.4×10-5Scm-1的离子电导率，并且与金属钠阳极的界面稳定性增强。受益于这些优势,用PE-PEO/NaTFSI组装的Na-Na对称电池显示出高临界电流密度（1mAcm-2）和出色的长期循环稳定性（在0.3mAcm-2下3000小时）。全固态Na||PE-PEO/NaTFSI||Na3V2(PO4)3硬币电池具有优越的循环性能，当与6mgcm-2的阴极负载匹配时，将初始容量的93％保留190次循环。同时,袋装电池在滥用测试后可以稳定工作，证明了它的灵活性和安全性。这项工作提供了一个有前途的策略，同时实现薄，高强度,和全固态金属钠电池的安全固态电解质。
