The effects of PVAc on surface morphological and electrochemical performance of P(VdF-HFP)-based blend solid polymer electrolytes for lithium ion-battery applications

Solid polymer electrolytes (SPEs) have attracted ever increasing attention due to their huge potential applications in all-solid-state Li-ion batteries. High ionic conductivity and large extended electrochemical stability of SPEs are crucial for the high performance of Li-ion batteries. In this article, we demonstrate the effects of PVAc in P(VdF-HFP)-LiTFSI-EC complex, resulting in blend solid polymer electrolytes (BSPEs), were successfully prepared via solution casting technique. This method utilized the advantages of both polymers, resulting in superior ionic conductivity with enhanced mechanical integrity. Among the various concentrations, 10wt% PVAc in P(VdF-HFP)-LiTFSI-EC exhibited a maximum ionic conductivity of 1.1x10(-3)Scm(-1), which is attributable to the suppression of PVdF crystalline phase and high Li-salt dissociation. The complex formation, surface morphology, thermal behavior, and thermal stability of BSPEs were systematically analyzed by FTIR, SEM, DSC, and TGA respectively. In addition, this sample shows a good electrochemical stability window (4.7V) and Li transference number (0.29), which suggest that this could be a promising candidate for Li-ion batteries.