Carbon-Encapsulated Co3O4 Nanoparticles as Anode Materials with Super Lithium Storage Performance

A high-performance anode material for lithium storage was successfully synthesized by glucose as carbon source and cobalt nitrate as Co3O4 precursor with the assistance of sodium chloride surface as a template to reduce the carbon sheet thickness. Ultrafine Co3O4 nanoparticles were homogeneously embedded in ultrathin porous graphitic carbon in this material. The carbon sheets, which have large specific surface area, high electronic conductivity, and outstanding mechanical flexibility, are very effective to keep the stability of Co3O4 nanoparticles which has a large capacity. As a consequence, a very high reversible capacity of up to 1413 mA h g(-1) at a current density of 0.1 A g(-1) after 100 cycles, a high rate capability (845, 560, 461 and 345 mA h g(-1) at 5, 10, 15 and 20 C, respectively, 1 C = 1 A g(-1)), and a superior cycling performance at an ultrahigh rate (760 mA h g(-1) at 5 C after 1000 cycles) are achieved by this lithium-ion-battery anode material.