Increased porous morphology and thermal degradation of electron beam-irradiated PVDF-HFP/LiCLO4 polymer electrolyte

The effect of 8MeV energy electron beam radiation at 40, 80 and 120kGy dosage on surface morphology and thermal properties of lithium perchlorate-doped poly (vinylidene fluoride-co-hexafluoropropylene) polymer electrolyte films have been studied. The field emission scanning electron microscopic image shows small-porous structured morphology for unirradiated film, but it changed drastically into large and deep porous structure as well as the size of spherulites is reduced for 120kGy confirming the influence of irradiation on morphology. The atomic force microscope reveals the significantly changed surface roughness of unirradiated film from 116.8 to 123.4nm with a hill-like pattern morphology for 120kGy confirming the increased amorphousity after irradiation. The thermal study confirmed that the decrease in the melting point of unirradiated film 160.86-155.24 degrees C for 120kGy doses is attributed to the formation of defects by the chain scissioning process resulting in the degradation of polymer electrolytes at high dose.