Ultra-Thin ReS₂ Nanosheets Grown on Carbon Black for Advanced Lithium-Ion Battery Anodes

ReS₂ nanosheets are grown on the surface of carbon black (CB) via an efficient hydrothermal method. We confirmed the ultra-thin ReS₂ nanosheets with ≈1-4 layers on the surface of the CB (ReS₂@CB) by using analytical techniques of field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). The ReS₂@CB nanocomposite showed high specific capacities of 760, 667, 600, 525, and 473 mAh/g at the current densities of 0.1 (0.23 C), 0.2 (0.46 C), 0.3 (0.7 C), 0.5 (1.15 C) and 1.0 A/g (2.3 C), respectively, in conjunction with its excellent cycling performance (432 mAh/g at 2.3 C; 91.4% capacity retention) after 100 cycles. Such LIB performance is greatly higher than pure CB and ReS₂ powder samples. These results could be due to the following reasons: (1) the low-cost CB serves as a supporter enabling the formation of ≈1-4 layered nanosheets of ReS₂, thus avoiding its agglomeration; (2) the CB enhances the electrical conductivity of the ReS₂@CB nanocomposite; (3) the ultra-thin (1-4 layers) ReS₂ nanosheets with imperfect structure can function as increasing the number of active sites for reaction of Li⁺ ions with electrolytes. The outstanding performance and unique structural characteristics of the ReS₂@CB anodes make them promising candidates for the ever-increasing development of advanced LIBs.