Rational design of Co3O4/Co/carbon nanocages composites from metal organic frameworks as an advanced lithium-ion battery anode

In this paper, Co-based metal organic frameworks were prepared through a facile method. After successive carbonization and oxidation treatment, the Co3O4/Co/carbon nanocages (COCCNCs) with hollow dodecahedral shape were obtained. Co3O4/Co/carbon nanocages with a high surface area (183.9 m2 g−1) and uniform pore distribution were employed as an anode material for LIBs and exhibited a high reversible specific capacity (850 mA hg−1 at 100 mA g−1), improved Coulombic efficiency, superior rate capability (485 mA hg−1 at a high current density of 5000 mA g−1) and excellent cycling stability (505 mA hg−1 can be remained after 600 cycles at 2000 mA g−1). Such a superior lithium storage performance is largely ascribed to the unique architecture composed of well-dispersed Co3O4 (ca. 9 nm) and Co (ca. 5 nm) nanocrystals embedded in hollow carbon nanocages with graphitic structure. This architecture not only avoids particle aggregation and nanostructure cracking upon cycling, but also provides continuous and flexile conductive carbon frameworks to facilitate the fast ions and electrons transportation.