Flexible Binder for S@pPAN Cathode of Lithium Sulfur Battery

Sulfurized pyrolyzed poly(acrylonitrile) (S@pPAN) composite as cathode material of Li-S battery realizes a solid-solid conversion reaction mechanism without dissolution of polysulfides. However, its surface and interface characteristics influence the electrochemical performance significantly, and there are also obvious volume changes during electrochemical cycling In this study, single-walled carbon nanotubes (SWCNT) and sodium carboxymethyl cellulose (CMC) were used as binder for S@pPAN cathode to regulate the surface of S@pPAN and alleviate volume changes during charging and discharging At a current density of 2C, capacity retention rate of the batteries after 140 cycles was 84.7%, and a high specific capacity of 1147 mAh.g(-1) can still be maintained at a high current density of 7C. The ultimate tensile strength for the film of the composite binder increases by 41 times after adding SWCNT, and the composite binder guarantees a more stable electrode interface during operation, thereby effectively improves the cycle stability of the as sembled lithium-sulfur batteries.

Automated summary

The study investigates the use of SWCNT and CMC as binders to regulate the surface characteristics of the S@pPAN cathode and mitigate volume changes during charging and discharging. The batteries demonstrate high capacity retention and specific capacity at high current densities, indicating improved cycle stability.