Olivine structured LiFePO4 cathode is the promising cathode active material for lithium secondary batteries due to its low cost and quite excellent reversibility. On the other hand, lithium polymer secondary batteries (LPBs) have been studied for the purpose of large-scaled batteries (for example, electric power load leveling). In this study, we prepared LPBs using the LiFePO4 cathode. By measuring the charge-discharge properties and electrochemical impedance spectroscopy, basic properties were investigated compared with the LPBs using the 4V-class LiCoO2 cathode.
