The lithium–sulfur (Li–S) battery has been attracting tremendous interest as a promising “beyond Li-ion” device, because of its high theoretical specific capacity and energy density [1-4]. However, its widespread applications, such as electric vehicles and large-scale grid-based energy storage systems, are still plagued with several issues and challenges. For example, the intrinsic insulating nature of sulfur makes it difficult to achieve high active material utilization. Additionally, the polysulfide intermediates are highly soluble in the benchmarked ether-based electrolytes, resulting in a severe redox shuttle effect between the sulfur cathode and Li anode. This undesired shuttle phenomenon can lead to a significant loss of active material, fast capacity fading and low Coulombic efficiency.

In this work, we incorporated nickel sulfide into the sulfur cathode design through a facile two-step strategy. Note that nickel sulfide here can trap the polysulfide intermediates and inhibit the shuttle effect owing to its binding interactions with polysulfide. Moreover, the low resistivity of nickel sulfide is expected to facilitate the redox kinetics of the adsorbed polysulfides. As a result, this hybrid cathode with a sulfur loading of 4.0 mg/cm² could manifest an excellent electrochemical performance at a high current density.

References

[1] S. Zhang, K. Ueno, K. Dokko, M. Watanabe, Adv. Energy Mater., 5 (2015) 1500117.

[2] K. Dokko, N. Tachikawa, K. Yamauchi, M. Tsuchiya, A. Yamazaki, E. Takashima, J.W. Park, K. Ueno, S. Seki, N. Serizawa, M. Watanabe, J. Electrochem. Soc., 160 (2013) A1304-A1310.

[3] Z. Li, S. Zhang, C. Zhang, K. Ueno, T. Yasuda, R. Tatara, K. Dokko, M. Watanabe, Nanoscale, 7 (2015) 14385-14392.

[4] Z. Li, S. Zhang, S. Terada, X. Ma, K. Ikeda, Y. Kamei, C. Zhang, K. Dokko, M. Watanabe, ACS Appl. Mater. Interfaces, 8 (2016) 16053-16062.