Nitrogen-doped carbon nanotube sponge with embedded Fe/Fe3C nanoparticles as binder-free cathodes for high capacity lithium–sulfur batteries

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 6; no. 36; pp. 17473 - 17480
• Main Authors: Yu-Si, Liu, Ma, Chao, Yu-Lin, Bai, Xue-Yan, Wu, Qian-Chen, Zhu, Liu, Xin, Xing-Hua, Liang, Xiao, Wei, Kai-Xue, Wang, Jie-Sheng, Chen
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 2018
• Subjects: Batteries; Carbon; Carbon nanotubes; Cathodes; Cementite; Coating effects; coatings; Electrochemical analysis; Electrochemistry; energy; Energy storage; Iron carbides; Lithium; Lithium sulfur batteries; Melamine; Nanoparticles; Nanotechnology; Nanotubes; Nitrogen; Storage batteries; Sulfur; Sulfur content; synergism; Synergistic effect
• ISSN: 2050-7488; 2050-7496; 2050-7496
• DOI: 10.1039/c8ta06040a

Lithium–sulfur (Li–S) batteries as a promising next-generation energy storage device have received increasing attention recently. However, it is still challenging to achieve high sulfur loading and high areal capacity in the cathodes. Herein, we design a composite of carbon-wrapped Fe/Fe3C nanoparticles grown in a carbonized melamine sponge (Fe/Fe3C@N-CNT) as a free-standing conductive framework and host scaffold for sulfur loading. High sulfur content up to 86.9 wt% and overall mass loading as high as ∼14.44 mg cm−2 are achieved in the resultant Fe/Fe3C@N-CNT/S composite. A high discharge capacity of 1359 mA h g−1 is delivered for this Fe/Fe3C@N-CNT/S composite at 0.1C, and 561 mA h g−1 is retained after 150 cycles. The high electrochemical performance of this Fe/Fe3C@N-CNT/S composite is attributed to the synergistic effect of Fe/Fe3C nanoparticles, carbon coating, and N-doped carbon nanotubes in the Fe/Fe3C@N-CNT cathode.