Nitrogen-doped carbon nanotube sponge with embedded Fe/Fe 3 C nanoparticles as binder-free cathodes for high capacity lithium–sulfur batteries

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2018, Vol.6 (36), p.17473-17480
• Main Authors: Liu, Yu-Si, Ma, Chao, Bai, Yu-Lin, Wu, Xue-Yan, Zhu, Qian-Chen, Liu, Xin, Liang, Xing-Hua, Wei, Xiao, Wang, Kai-Xue, Chen, Jie-Sheng
• Format: Article
• Language: English
• ISSN: 2050-7488; 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/Fe 3 C nanoparticles grown in a carbonized melamine sponge (Fe/Fe 3 C@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/Fe 3 C@N-CNT/S composite. A high discharge capacity of 1359 mA h g −1 is delivered for this Fe/Fe 3 C@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/Fe 3 C@N-CNT/S composite is attributed to the synergistic effect of Fe/Fe 3 C nanoparticles, carbon coating, and N-doped carbon nanotubes in the Fe/Fe 3 C@N-CNT cathode.