Development of nonflammable lithium ion battery using a new all-solid polymer electrolyte

For solving the safety issue of lithium ion batteries, the choice of all-solid polymer electrolyte is one of the possible solutions. However, usual polyethylene oxide including lithium supporting agent has not enough lithium ion conductivity as electrolyte for practical use. Some of our research group (M. W. and H. M.) have tried the addition of plasticizer such as borate ester or aluminate ester (Al-PEG) into monomer mixture containing lithium salt for increasing the ionic conductivity resulting in polymer electrolyte after polymerization. For such all-solid polymer electrolyte (SPE), the ionic conductivity, a value of 10(-3) S/cm has been attained at 60 A degrees C and the value will be acceptable for practical use. Since the SPE also has nonflammable property, the combination of the SPE with suitable cathode and anode may produce a new all-solid polymer battery with safety. In the present study, the SPE containing Al-PEG and dimethoxy ethylene glycol mixture as the plasticizer was newly combined with spinel Li4Ti5O12 anode and olivine LiFePO4 cathode objecting for developing stationary battery. The cell performance of the new combination will be reported at 30 A degrees C and 50 A degrees C.