A step towards sustainable bio-based solid polymer electrolytes for batteries: Terpene-based block copolymer-nanostructured self-assembly

Abstract

Herein, novel partially Bio-Based Solid Polymer Electrolytes B2SPE were elaborated by synthesizing block copolymers BCP with a thermoplastic PolyThymylAcrylate (PTA) block derived from biomass and an elastomeric ion conductive Poly(PentaFluoroStyrene-graft-Ethylene Glycol) (PPFS-graft-PEG) block. The copolymers were obtained via Nitroxide Mediated Polymerization NMP of TA and PFS monomers successively, followed by a para-thiol modification of the PPFS block using a PEG-thiol containing 6 ethylene oxide (EO) units. We investigated the effect of different PPFS-PEG proportions in the BCP as well as the used of various bis(trifluoromethanesulfonyl)imide (TFSI) conductive salts (Li, Na, and K) on the thermal and ionic conductive properties of the B2SPEs related to their morphology. Indeed, the evaporative drying induced the self-assembly of the raw Bio-Based Block CoPolymers B2BCPs and their conductive homologues B2SPEs. The B2BCP self-assembly is slightly modified by the addition of TFSI conductive salts whatever the salts nature and content. The Li filled thermoplastic/elastomeric PTA-block-(PPFS-graft-PEG), as LiTFSI-based B2BCP, ionic conductivity was improved significantly by tuning the composition of the copolymer and salt ratio, demonstrating the potential of such nanostructured B2SPEs. This concept paves the way as a sustainable approach towards bio-based solid polymer electrolyte B2SPE with lower carbon footprint for battery innovation.