Nitrogen and Oxygen Dual Self-Doped Flexible PPTA Nanofiber Carbon Paper as an Effective Interlayer for Lithium–Sulfur Batteries

The shuttle effect of polysulfides during charge and discharge processes is a critical problem that seriously limits the application of Li–S batteries. Herein, a flexible nanofiber carbon paper was first fabricated from poly(p-phenylene terephthalamide) (PPTA) nanofiber and carbon fiber (CF) as an effective interlayer for high-performance lithium–sulfur batteries. The nanofiber carbon paper processes abundant meso-/micropores and high heteroatom contents, which are beneficial for the inhibition of the shuttle effect of polysulfides through physical adsorption and chemical catalysis. Therefore, the electrochemical reaction kinetics are remarkably improved. The primary discharge capacity of cells with PPTA/CF carbon paper achieves 1373 mA h g–1 at 0. 1 C with a 96.2% utilization rate of active materials. The specific reversible discharge capacity maintains 755 mA h g–1 at 5 C, with a 99.7% coulomb efficiency. This flexible nanofiber carbon paper will have a promising application in high-performance lithium–sulfur batteries.