PEO-based electrolytes blended with star polymers with precisely imprinted polymeric pseudo-crown ether cavities for alkali metal ion batteries

Abstract

Tailor-made star polymers comprised of cross-linked cores containing polymeric pseudo-crown ether cavities and linear poly(ethylene oxide) (PEO) arms are designed via cation template-assisted cyclopolymerization. The pseudo-crown ether cavities in cross-linked cores can coordinate with alkali metal cations and offer more cation diffusion channels. Moreover, the functional linear PEO arms are beneficial to the conductivity of cations and increase the compatibility with the PEO matrix. By selecting monomers with different chain lengths and cation templates, the tailor-made star polymers can be employed as efficient conductors for lithium-ion, sodium-ion, and potassium-ion batteries. The lithium-ion conductivity of the solid-state polymer electrolytes obtained from a potassium cation template and poly(ethylene glycol) dimethacrylate (PEGDMA750) monomer (K-SPE750-Li) is 2.82 × 10-5 S cm-1 at 20 °C. Furthermore, the cell of Li|K-SPE750-Li|LiFePO4 shows stable cycling performance and a good rate property.