A coral-like composite of CoP-modified polyaniline-derived carbon chain skeleton as an efficient sulfur host for lithium-sulfur batteries

Abstract

Lithium-sulfur batteries (LSBs) have attracted wide attention in the field of rechargeable batteries due to their high theoretical energy density. However, the severe “shuttle effect” of lithium polysulfides (LiPSs) and the slow conversion kinetics are key factors restricting the commercial application of LSBs. To address these issues, we designed and prepared a coral-like composite of CoP-modified polyaniline-derived carbon chain skeleton (CoP/C) as the sulfur host for LSBs. The carbon chains can provide multidirectional channels for the transport of Li+ and electron; and the uniformly scattered CoP can adsorb the LiPSs through chemical adsorption and simultaneously promote their conversion, thus the “shuttle effect” can be effectively alleviated. Meanwhile, the effect of the amount of aniline monomer on the electrochemical performance of sulfur cathode were studied. After sulfur loading, the CoP/C-300/S (with aniline monomer addition of 300 μL) exhibits the best electrochemical performance. At 1 C, after 500 cycles, it still maintains a reversible specific capacity of 478 mA h g−1, with a decay rate of 0.074% per cycle, indicating its excellent cycling stability. This work provides a new approach for the application of CoP material in advanced LSBs.