Moss-like porous biochar loading Co 3 O 4 nanoparticles as sulfur host maintain the stability of Li-sulfur batteries

The combination and structural regulation of physical adsorption and chemisorption carriers for polysulfides play an important role in limiting the shuttle effect of lithium-sulfur batteries (LSBs). So, in this paper, N, Co co-doped moss-like porous biochar (Co–N/CWPC) is synthesized and used as the sulfur host for LSBs. A large number of pores in the “moss” provide space for sulfur storage and volume expansion. And the introduction of N, Co provides plentiful catalytic adsorption sites, which can not only effectively limit the shuttle of polysulfides but also accelerate the conversion rate of polysulfides to the final discharge products. Moreover, Co also promotes graphitization and improves electrical conductivity of the biochar. After sulfur injection, the electrode shows an initial capacity of 787 mAh g −1 at 0.5 C and maintaining a capacity of 500 mAh g −1 after 500 cycles, the capacity decay rate is 0.07%. Even at a discharge rate of 1.0 C, it still maintained a capacity of 373 mAh g −1 after 1000 revolutions, with a capacity decay rate of 0.04%.