In order to address the interfacial issues associated with the rigidness of polyacrylonitrile (PAN) polymer electrolyte, polyethylene oxide (PEO) polymer electrolyte layers are firstly proposed to paste on the both sides of PAN membrane, resulting in the formation of a sandwiched PEO-PAN-PEO polymer electrolyte. Under the high temperature, the flexible PEO offers the enlarged contact area between the electrolyte and the electrode with the reduced internal resistance. It indicates that the novel sandwich polymer electrolyte is one of the ideal candidates for all-solid lithium battery. The cell consisting of metallic Li anode and LiFePO4 cathode demonstrates the initial discharge capacity of 153 mAh/g and the capacity retention rate of 87% at 40th cycle under the operation temperature of 60℃.
