A review on polymer electrolyte materials in context to modifications in PVDF-HFP polymer host

Polymer electrolytes emerged as a viable candidate for advanced battery technologies. Incitation to develop polymer electrolytes emanate from the issues faced by the liquid and solid electrolyte based lithium ion batteries (LIBs). Polymer electrolytes highlighted the improvement in ion conductivity, electrochemical stability, enhanced safety, strength and flexibility. Different polymers are being explored for their remarkable performance in the LIBs. In this context, the key polymer used in modern batteries is poly(vinylidene fluoride-co-hexafluoropropylene), i.e., PVDF-HFP, which has excellent features like thermal stability, mechanical strength, Li-ion conductance, metal salt absorption, and other properties measured in battery formations like discharge capacity, coulombic efficiency, etc. This polymer is used in both solid (including the composite solid electrolyte) and gel polymer electrolytes. Keeping in view the energy demand and material scarcity in renewable energy storage, various properties of the polymer electrolytes need to be improved. This progress demands the addition of certain additives in sole PVDF-HFP. In this context, this article exhaustively reviewed the role of mixing other plasticizers, active and passive fillers in PVDF-HFP with their effect on the various parameters along with future materials. The role of future materials like metal organic frameworks (MOF) will certainly revolutionized the progress in electrolyte material thus focusing on the real-world performance and commercialization of the LIBs.