A novel strategy for synthesizing the large size Co9S8@C nanosheets as anode for lithium-ion batteries with superior performance

The cobalt sulfides have become the focus materials on the lithium ion batteries application in which the Co9S8 with the nanosheet structure is the promising candidate for anode material in high-energy and high-power lithium ion batteries. By introducing a novel strategy with the organic-inorganic hybrid Co9S8-DETA (DETA=Diethylenetriamine) as the precursor, the large size Co9S8@C nanosheets have been successfully prepared via a calcination process. Due to uniform two-dimensional structure of Co9S8 and the amorphous carbon layer coating, the as-prepared Co9S8@C nanosheets exhibited excellent lithium ion storage performance as an anode material. The reversible capacity could be retained at 595 mAh g−1 after 160 cycles at 0.2 A g−1. The excellent performances of this nanocomposite offer numerous opportunities for other sulfides as a new anode in lithium ion batteries.