Realizing sulfurized polyacrylonitrile cathode in ether-based electrolyte

Abstract

The sulfurized polyacrylonitrile (SPAN) cathode presents an excellent potential for achieving high energy density in lithium-sulfur batteries (LSBs). However, this cathode can only operate efficiently in the presence of a lithium metal anode (LMA)-unfriendly carbonic ester-based electrolyte. The challenge lies in enabling the SPAN cathode to function effectively with an LMA-friendly ether-based electrolyte. In this study, we have successfully designed a custom ether-based electrolyte by dissolving LiNO3 in diethylene glycol dimethyl ether, supplemented with a few Li bisfluorosulfonimide additives. As anticipated, this specially formulated electrolyte exhibits remarkable compatibility with both LMA and the SPAN cathode. The resulting Li|SPAN cell exhibits impressive performance, achieving a high capacity of 1430 and 1066 mAh g−1 at 0.5 and 6 C, respectively, and maintaining long-term stability with 80 % capacity retention after 1000 cycles at 2 C. Our findings demonstrate that this designed ether-based electrolyte plays a pivotal role in facilitating the formation of a stable and highly conductive interfacial layer between both the anode and cathode, leading to enhanced LSB performance.