| The polymer electrolyte is one of the key to development of lithium batteries. In this work, solution casting method was used to prepare solid composite polymer electrolyte (SCPE) films with poly(ethylene oxide) (PEO) as polymer base. The properties of electrolyte films were characterized using electrochemical performance testing, X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), electrochemical impedance spectra (EIS) and tensile strength test. The effects of each single component and SCA-inorganic particles composite modified were studied, while the composite modified mechanism was discussed in some detail.The relations between electrolyte membrane properties and lithium salts, inorganic powders and SCA were studied by the single component variable experimental. Both SCA1 and SiO2 were used as additives for composite modified, which was decided according to the results of performance compare.The composite modified by SCA1-SiO2 got obvious performance that electrochemical and mechanical properties were significantly improved, and better than the modified of SiO2 or SCA alone. The ionic conductivity of PEO8-LiClO4-5wt%SiO2-SCA1 reached 1.2×10-3S/cm, ion transport number is 0.71, and yield strength and tensile strength are 2.0MPa and 5.5 MPa respectively, plastic strain is more than 500% (25℃). The test results of FTIR,XRD,DSC and SEM showed that the composite modified play a role in three main fields:①To reduce the crystallization. The crystallinity of pure PEO is 81.1%, PEO8-LiClO4-5.0wt%SiO2 is 20.3%, while PEO8-LiClO4-5.0wt%SiO2-SCA1 is only 2.4%.②The addition of SCA1 make SiO2 particles better solubility and decentralization, and inhibit aggregation and deposition of SiO2 particles.③SCA may smooth SCPE film, which favors to low contact resistance between the film and electrode. The essence of the changings is the result of synergy between SCA1 and SiO2.
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