Silane coupling agents (SCA) was used as additives to improve the performance of the PEO-based solid composite polymer electrolytes (SCPE). The properties of electrolyte films were characterized using XRD, DSC, SEM, FTIR, EIS and tensile strength test. The effect of the SCA on the performance of the SCPE was discussed. The test results show that the crystallinity of SCPE film decreases obviously, the electrochemical and mechanical properties are improved when the SCA was added into the SCPE film, the conductivity of the PEO₈-LiClO₄-5%SiO₂-SCA reach up to 9.0×10^－4 S/cm and yield stress is 2.04 MPa (25 ℃), simultaneously, SCA may smooth SCPE film, which favors to low contact resistance between the film and electrode.

Key words: solid polymer electrolyte, PEO, silane coupling agent, SiO₂, modification