Chemical and physical synergism between PAF-54 and SFPEEKK for effective shuttle effect inhibition of lithium–sulfur battery

Abstract

Lithium-sulfur batteries (LSBs) have garnered considerable interest due to their high theoretical discharge specific capacity and energy density. However, the formation of lithium polysulfides during the electrochemical redox process leads to the loss of active material and undesirable electrochemical properties. In this study, we developed a novel Janus separator (FSP-PAF) prepared by coating PAF-54 compounded sulfonated poly (ether ether ketone ketone) and Super P onto the PE separator to effectively mitigate the shuttle effects. The FSP-PAF exhibited a high ionic conductivity of 6.4 × 10−4 S/cm and a Li+ transfer number (tLi+) of 0.72. Lithium-sulfur batteries assembled with FSP-PAF demonstrated a capacity of 1112 mA h/g at 0.2 °C, and a remarkable capacity retention rate of 65 % after 500 cycles, and maintained a capacity of 720 mA h/g even at a high rate of 3 °C. This synergistic effect involving PAF-54, sulfonated poly (ether ether ketone ketone), and Super P held great promise for the application of LSBs.