Construction of a lithium ion transport network in cathode with lithiated bis(benzene sulfonyl)imide based single ion polymer ionomers

• Construction of ion transport network with lithiated single ion conducting polymer ionomers.
• Charge delocalized anion-incorporated polymer electrolyte with Mn close to 60,000.
• Ionic conductivity of 0.14 mS cm−1 at room temperature with t+ = 0.92.
• Discharge capacity of 165 mAh g−1 at 0.2C and 123 mAh g−1 at 0.5C at room temperature.

We demonstrate a novel method to construct a lithium ion transport network in cathode materials by replacing PVDF with lithiated poly(bis(4-carbonyl benzene sulfonyl)imide-co-bis(4-amino benzene sulfonyl)imide) as the binder. The single ion conducting polymer was synthesized via polycondensation of bis(4-carbonyl benzene sulfonyl)imide and bis(4-amino benzene sulfonyl)imide followed by lithium ion exchange. By blending the ionomers with LiFePO4 and acetylene carbon, the ionic network was well constructed, resulting in a maximum use of active cathode material inside the cathode. The membrane of the polymer electrolyte exhibits an ionic conductivity of 0.14 mS cm−1 at room temperature, a high ion transference number of 0.92 and a wide electrochemical window of 4.5 V (vs. Li+/Li). A lithium ion battery assembled with the single ion conducting polymer electrolyte delivers excellent performance at room temperature with various C-rates.