Lithium-oxygen (Li-O2) batteries have attracted much attention due to their high theoretical specific energy (3505 Wh kg-1) and energy density (3436 Wh l-1) compared to conventional lithium ion batteries, and are one of the most promising high-energy-storage systems for electric vehicles (EVs) and hybrid electric vehicles (HEVs). However, their safety issues derived from the dendritic growth of lithium and the flammability of electrolyte have limited their commercialization. This eventually leads to a much shorter cycle life than would be expected. Therefore, the application of solid polymer electrolyte is the key to enhance the cycling stability of Li-O2 batteries. In this work, for the first time, poly(ethylene glycol) (PEG)-based solid polymer electrolyte (SPE) was used in Li-O2 batteries. The PEG-based SPEs were prepared by thermal curing using a homogeneous solution of poly(ehylene glycol) methyl ether methacrylate (PEGMA) monomers, a tanic acid (TA) cross linker, a initiator (AIBN), a lithium salt (LiTFSI) and a solvent (THF). The ionic conductivity of PEG-based SPE was 3.028 X 10-4 S cm-1 at 80 oC. The resulting Li-O2 cell was able to reach 30 cycles and show a discharge capacity of 3774 mAh g-1carbon in ambient air at 80 oC. Our results demonstrate that the PEG-based SPE could be a promising strategy for Li-O2 batteries upon future application.

Application of PEG-based solid polymer electrolyte to all-solid-state Li-O2 batteries

253rd National Meeting (2017)

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