An All-Solid-State Sodium-Sulfur Battery Using a Sulfur/Carbonized Polyacrylonitrile Composite Cathode

An all-solid-state sodium-sulfur (Na-S) battery using a S/CPAN (carbonized polyacrylonitrile) composite cathode and poly(ethylene oxide) (PEO) electrolyte was prepared and tested at 60 degrees C. The S/CPAN composites was synthesized by heating a mixture of S and PAN at 600 degrees C. The solid polymer electrolytes consisted of PEO, NaFSI, and different amounts nano-TiO2. Moreover, the PEO-NaFSI-1% TiO2 electrolyte was chosen to be the electrolyte in all-solid-state Na-S battery due to its high ionic conductivity (4.89 x 10(-4) S cm(-2) at 60 degrees C) as well as outstanding electrochemical and thermal stability. The specific capacity of the S/CPAN composite cathode material can be 252 mAh g(-1) (713 mAh g(sulfur)(-1)) at the second cycle, and it still remains 251 mAh g(-1) (710 mAh g(sulfur)(-1)) after 100 cycles with a Coulombic efficiency near 100%.