Electrochemical study of Ionic Liquid based polymer electrolyte with graphene oxide coated LiFePO4 cathode for Li battery

Abstract

Ionic Liquid (IL) based polymer electrolytes using polymer poly ethylene oxide (PEO), salt lithium bis(fluoromethylsulfonyl)imide and IL N-propyl-N-methylpyrrolidinium-bisfluorosulfonylimide (PYR13FSI) are synthesized by solution cast method. Using different experimental techniques, good thermal stability and wide electrochemical window are observed for synthesized polymer electrolytes. Maximum Li+ conductivity is found for 10% IL containing polymer electrolyte so, it is used in Li cell preparation. LiFePO4 (LFP) cathode and graphene oxide wrapped LFP cathode (GO-LFP) are also prepared to observe the effect of graphene oxide coating in electrochemical performance of the Li cell. From charge –discharge process, high specific discharge capacity (~163 mAh g−1 at 0.1 C) is found for GO-LFP as compared to LFP cathode. GO-LFP cathode shows good cyclability and Coulombic efficiency up to 100 cycles. High charge-discharge capacity of GO-LFP is noticed even at higher current rate. © 2018 Elsevier B.V.