NiS 2 nanoparticles anchored on open carbon nanohelmets as an advanced anode for lithium-ion batteries.

Low intrinsic conductivity and large volume expansion seriously restrict the efficient lithium storage performance of metal sulfides. Here, we fabricate a hybrid material of NiS 2 nanoparticles/carbon nanohelmets (NiS 2 /CNHs) to address the above issues. As an anode material in lithium-ion batteries, NiS 2 /CNHs exhibit excellent cycling stability (490 mA h g -1 after 3000 cycles at 5 A g -1 ) and rate properties (412 mA h g -1 at 10 A g -1 ), outperforming other NiS x -based anode materials. These remarkable performances originate from the three-dimensional helmet-like integrated architecture of NiS 2 /CNHs, which reduces the electrode resistance due to the tight combination between NiS 2 and CNHs, provides efficient diffusion paths for the electrolyte and Li + owing to the amorphous nanoporous carbon structure, and significantly mitigates the aggregation and buffers the large volumetric expansion of NiS 2 nanoparticles upon long-term cycling thanks to the open three-dimensional architecture and well-dispersed NiS 2 nanoparticles on it.