Small intestinal structure Ni2P-CNTs@NHCF nanoreactor accelerating sulfur conversion kinetics for high performance lithium-sulfur batteries

It is extremely desirable to develop efficient sulfur reduction reaction (SRR) electrocatalysts for lithium-sulfur (Li–S) batteries. In this work, a small intestinal structure sulfur electrocatalyst, viz. Ni 2 P-CNTs@NHCF nanoreactor, is designed by a facile coaxial electrostatic spinning strategy. Experimental results and theoretical calculations indicate that the synergetic effect of Ni–S and Li–P dual chemical bonds between Ni 2 P and lithium polysulfides (LiPSs) optimizes the chemisorption energy of LiPSs and reduces reaction energy barriers from liquid LiPSs to solid Li 2 S, thus achieving the successive immobilization-diffusion-conversion process of sulfur species. As a result, the cell modified with Ni 2 P-CNTs@NHCF catalyst exhibits the excellent reversible capacities and cyclic stability. With the high sulfur loading of 8.13 mg cm −2 and low electrolyte/sulfur ratio of 6 μL mg −1 , it displays a significant initial areal capacity of 13.4 mAh cm −2 and remains 7.1 mAh cm −2 after 80 cycles at 0.1 C. This work offers an effective strategy on rational design of efficient electrocatalysts, and provides considerable insights into the mechanical comprehension of SRR.