A star-shaped solid composite electrolyte containing multifunctional moieties with enhanced electrochemical properties for all solid-state lithium batteries

Limited ionic conduction and poor solid/solid interfacial stability are crucial characteristics that impede the practical application of solid polymeric electrolytes. Herein, a star-shaped solid composite electrolyte (SCE) containing multifunctional components, including anion-trapping boron moieties (B-PEGMA), poly(ethylene glycol)methyl ether methacrylate (PEGMEM) and octavinyl octasilsesquioxane (OV-POSS) nanofiller, was developed via a simple free radical polymerization method. The unique star-shaped structure induced by OV-POSS is beneficial to increasing the movement of polymer chains and forming continuously interconnected ion-conducting channels and the boron moieties can promote lithium salt dissociation and increase the effective transmission of Li + in the electrolyte. This SCE exhibits an extremely high ionic conductivity of 3.44 × 10 −4 S cm −1 and a high Li ion transference number of 0.58 at 25 °C, as well as excellent interfacial compatibility with the Li electrode leading to excellent rate performance and good cyclic stability in all-solid-state Li batteries.