Three-dimensional interwoven CoS2/reduced graphene oxide/carbon nanotubes composite as anode materials for high-performance lithium-ion batteries

Abstract

CoS2 exhibits abundant redox reactions, high theoretical capacity, excellent, mechanical properties, and is regarded as a prospective electrode material. However, rational design of CoS2 composites with high capacity and ultra-long cycle life remains a major challenge. In this work, we formed CoS2/rGO/CNT electrode materials by compositing reduced graphene oxide (rGO), carbon nanotubes (CNT) and CoS2 with a three-dimensional interwoven network. The elemental composition and three-dimensional network morphology were described using SEM, TEM, XRD, Raman, BET, TGA and XPS. The large loading area provided by the three-dimensional network for Li+ facilitates the effective diffusion of Li+ during the cycling process. In addition, the three-dimensional network acts as an adhesion substrate for CoS2 nanoparticles, mitigating the bulk change and reducing the aggregation of CoS2 nanoparticles. On the other hand, the tight bonding of CNT with CoS2/rGO facilitates fast transfer of electron in CoS2/rGO/CNT. The electrochemical measurement results show that after 1000 cycles, the capacity is 615.8 mAh/g at 2000 mA/g and can still reach 233.7 mAh/g at 5000 mA/g after 2000 cycles. The favorable electrochemical properties prove that CoS2/rGO/CNT is an excellent anode material for long-life lithium-ion batteries.