The present paper aims to develop solid polymer electrolyte elastomers for energy harvesting and storage devices under dynamic natural environment. The flexoionic elastomer was synthesized by grafting 1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (AMIMTFSI) to a triblock copolymer consisting of olefinic glycol moieties such as PEG-b-PPG-b-PEG end-capped with methacrylate groups (DMA). The strategy of grafting dissociated AMIM + cations to the polyglycol triblock copolymer network allows selective (or dominant) ion polarization by the mobile TFSI − anions undergoing oscillatory motion, the concept of which is similar to single-ion transport as a means of enhancing electrochemical performance in some solidstate polymer electrolyte batteries. The 60:40 PEG-b-PPG-b-PEG-DMA/AMIMTFSI elastomer achieved a high flexoelectric coefficient on the order of about 380 μC m −1 at 1 Hz and a high energy conversion efficiency of about 14.9% under oscillatory bending mode, which opens an opportunity for energy harnessing from rolling tires.