Hollow nanotubular clay composited comb-like methoxy poly(ethylene glycol) acrylate polymer as solid polymer electrolyte for lithium metal batteries

Solid polymer electrolytes (SPEs) shows increasing promise for all-solid-state batteries due to their high safety, high flexibility and low interfacial resistance. However, the low ionic conductivity at room temperature is the main barrier hindering the practical application of SPEs. Herein, hollow nanotubular clay composited comb-like methoxy poly(ethylene glycol) acrylate polymer electrolyte (HCPE) is fabricated by in-situ UV activated radical polymerization, which exhibits an improved ionic conductivity of 5.62 × 10⁻⁵ S cm⁻¹ at room temperature. The introducing of the branched structure helps reduce the regularity of polymer chains and decreases the proportion of crystalline regions of polymers. Moreover, the nanofiller feature and the special structure of halloysite nanotube (HNT) are beneficial for dissociating lithium salt, thus improving the ionic conductivity. Meanwhile, the designed composite solid-state electrolyte demonstrates high thermal stability and compatibility with Li metal, high electrochemical stability. The all-solid-state Li/HCPE/LiFePO4 cell delivers high rate capability and stable cycling performance at room temperature, which proves the great potential of HCPE for all-solid-state Li metal batteries.
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