Preparation and properties of gel polymer electrolytes based on tetrafunctional cross-linked PEG network

Thiol-yne click reaction between pentaerythritol tetrakis(3-mercaptopropionate) and α, ω-dipropiolate-terminated polyethylene glycol was carried out in propylene carbonate containing lithium bis(trifluoromethanesulfonyl)imideto obtain gel polymer electrolyte with tetra-branched network structure. The ionic conductivity was found to depend on the polymer content in the gel polymer electrolyte and the chain length of the polyethylene glycol constituting the tetra-branched network structure. These experimental results indicated that lithium cations moved not only within the electrolyte solution but also along the PEG chains that form a network structure.