Novel solid-state composite polymer electrolytes based on poly (ethylene oxide) (PEO) by using LiClO4 as doping salts and inorganic–organic hybrid poly (cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) microspheres as fillers were prepared. Electrochemical and thermal properties of PEO-based polymer electrolytes incorporated with PZS microspheres were studied. Differential scanning calorimetry (DSC) results showed there was a decrease in the glass transition temperature of the electrolytes and the crystallinity of the samples in the presence of the fillers. Maximum ionic conductivity values of 1.2 × 10−5 S cm−1 at ambient temperature and 7.5 × 10−4 S cm−1 at 80° were obtained and lithium ion transference number was 0.29. Compared with traditional ceramic fillers such as SiO2, the addition of PZS microspheres increased the ionic conductivity of the electrolytes slightly and led to remarkable enhancement in the lithium ion transference number.
