Nitrogen-doped carbon fiber foam enabled sulfur vapor deposited cathode for high performance lithium sulfur batteries

Lithium sulfur batteries are one of the most promising candidates for the next generation batteries due to its high energy storage density. However, the complicated fabricate method of the sulfur cathode limits its practical application. Recently, the fabrication of sulfur cathode via sulfur vapor deposition is becoming increasingly popular for the reason of simple process and easy industrialization. However, how to solve the severe shuttle effect of polysulfide during cycling remains a challenge in this kind of cathode. Herein, in order to decrease the immigration of polysulfide in the sulfur vapor deposition fabricated cathode, nitrogen-doped carbon fiber foam is designed by the carbonization of polyaniline treated cotton. The nitrogen species in nitrogen-doped carbon fiber foam act as the active sites for the capture of polysulfides, and the shuttle effect is suppressed effectively during cycling. With a high sulfur areal mass loading of 3 mg cm(-2), the prepared cathode exhibits a specific capacity of 443.7 mAh g(-1) and capacity retention over 97% after 500 cycles at 2C.