A polypropylene (PP) supported solid polymer electrolyte enables high-stability organic lithium batteries at low temperature

We innovatively used a polypropylene (PP) separator as a substrate and PEO-LiTFSI-SN as a paste to coat on both of the PP surfaces, and formed a sandwich-like solid polymer electrolyte (SPE). The SPE shows a conductivity of 4.22 × 10−3 S cm−1 at room temperature and 7.75 × 10−5 S cm−1 at 0 °C. The pyrene-4,5,9,10-tetraone (PTO)||SPE||Li battery shows a maximum discharge specific capacity of 187.8 mA h g−1 at a current density of 20 mA g−1 under 0 °C. After 100 cycles, the capacity could still be obtained at 88.4 mA h g−1, and the coulombic efficiency stayed stable at 98%. This work paved a new way for the development of solid-state organic batteries (SSOBs) at low temperatures.