Communication—Lithium Sulfonated Polyoxadiazole as a Novel Single-Ion Polymer Electrolyte in Lithium-Ion Batteries

A single-ion conductor polymer electrolyte was prepared and the effects of the ratio of isophthalic acid (IPA) to 4, 4'-diphenyl ether dicarboxylic acid (DPE) on the structure and electrochemical properties have been investigated. Results show that all the lithium sulfonated polyoxadiazoles (Li-SPODs) have excellent thermal stability (510 °C). The ionic conductivity of the Li-SPOD is 7.2 × 10−4 S cm−1 at room temperature when the IPA/DPE ratio is 6/4. A high Coulombic efficiency of 99.1% for the LiFePO4/6/4 li-SPOD SPEs/Li half-cell could be achieved with a capacity retention of 90.63% at a current density of 0.1 C after 25 cycles.