Patent ID: 7736782

Claim:
A proton conductive solid polymer electrolyte, comprising: a polypyridobisimidazole-based compound comprising a repeat unit and an acid, wherein the repeat unit is represented by Formula (1): where each of R 1 , R 2 , R 3 , and R 4 is selected from the group of a hydrogen atom, a C 1 -C 20 alkyl group, a C 6 -C 20 aryl group, a sulfonic acid group, a hydroxyl group, a nitro group and an amino group, wherein at least one of R 1 , R 2 , R 3 , and R 4 is selected from the group of a sulfonic acid group, a hydroxyl group, a nitro group, and an amino group; and n 1 is between 10 and 10,000.