Facile Li-ion conduction and synergistic electrochemical performance via dual functionalization of flexible solid electrolyte for Li metal batteries

Herein, a novel polymer electrolyte membrane based on poly(arylene ether sulfone)-g-poly(vinylethylene car-bonate)/poly(ethylene glycol) (PAES-g-PVEC/PEG) combined with 1-butyl-1-methylpyrrolidinium bis(tri-fluoromethyl sulfonyl)imide was prepared to achieve the superior electrochemical performance with good thermal and mechanical stability. The synergistic effect was provided for the lithium ion transport and elec-trochemical performance by the dual functional groups of polyether and polycarbonate grafted on the rigid PAES backbones. The membrane containing 30 mol% PVEC and 70 mol% PEG exhibited the ionic conductivity of 0.81 x 10(-3) S cm(-1) and Li (+) transference number of 0.65 at room temperature, maintaining the thermal and mechanical stability in the flexible solid state. As this membrane illustrated a good interfacial compatibility with Li metal electrode, the LiFePO4||Li cell demonstrated an outstanding cycling discharge capacity of ~151 mA h g(-1) and the coulomb efficiency 99% after 100 cycles under 0.1C. Based on this excellency, the PAES-g-PVEC/PEG electrolyte herein synthesized is considered to be a promising candidate for the application of all-solid-state lithium metal batteries with high power and energy density.

Automated summary

A novel polymer electrolyte membrane based on PAES-g-PVEC/PEG and 1-butyl-1-methylpyrrolidinium bis(trifluoromethyl sulfonyl)imide was prepared, which exhibited superior electrochemical performance, good thermal and mechanical stability. The dual functional groups of polyether and polycarbonate grafted on the PAES backbones provided a synergistic effect for lithium ion transport and electrochemical performance. The membrane containing 30 mol% PVEC and 70 mol% PEG showed high ionic conductivity and Li(+) transference number at room temperature, making it suitable for flexible solid state lithium metal batteries.