NiCo2S4 nanoparticles grown on graphene as the sulfur host for high-performance lithium/sulfur batteries

Lithium-sulfur (Li–S) batteries have drawn intensive research interest due to their high theoretical energy density. However, there remain several challenges that hinder their practical application, mainly coming from intermediate polysulfide dissolution and shuttling. Herein, we prepared NiCo2S4 nanoparticles grown on graphene as the sulfur host for high-performance Li–S batteries. Such nanosheet composite made of interconnected graphene can offer abundant space to carry the large amount of S, convenient pathways for both rapid Li+ and electrons transfer, and extra reversible capacity contribution. Particularly, each individual NiCo2S4 nanoparticle is polarized synergistically, thus preventing the amassment of soluble polysulfides benefiting from polar-polar interaction and improving sulfur utilization. As a result, the S@NiCo2S4/N-GO composite exhibits a stable capacity of 1199.2 mAh g−1 at 0.2 C after 100 cycles with capacity retention of 99.04%. Our work may offer a great potential in rational design of superior cathodes for the practical Li–S battery systems.