A novel ceramic/polyurethane composite solid polymer electrolyte for high lithium batteries

Abstract

Compared with the organic electrolyte, the solid electrolyte is more stable and non-volatile at high potential, which solves the decomposition problem of organic electrolyte and the potential safety hazard of flammability and explosion. Based on the advantages of inorganic solid electrolyte and polymer solid electrolyte, a ceramic/polyurethane composite polymer electrolyte (CPPE) based on Li0.35La0.55TiO3 (LLTO) and polyurethane (LPU) was prepared in this work. First, a linear polyurethane (LPU) was synthesized via 2,4-toluene diisocyanate (TDI) and poly(propylene oxide) (PPO), owing to the high ionic conductivity of LLTO and good mechanical property of LPU. The CPPE has a satisfactory lithium ion conductivity (3.8 × 10−4 S cm−1) at room temperature. Furthermore, the assembled LiFePO4|CPPE|Li battery exhibit excellent cycle performance at room temperature, the discharge capacity was still 149.8 mAh g−1 after 200 cycles and with a superior capacity retention of 97.8% at 0.5 °C. Additionally, the LiNi0.8Co0.1Mn0.1O2|CPPE|Li exhibited remarkable rate capacity that the initial capacity reached to 216.4 mAh g−1 at 0.1 °C and maintains the excellent specific capacity of 138 mAh g−1 at 1 °C. These findings suggest that CPPE provides a viable idea for the development of high-performance lithium batteries.