Cobalt Oxide-Carbon Nanosheet Nanoarchitecture as an Anode for High-Performance Lithium-Ion Battery

To improve the electrochemical performance of cobalt oxide owing to its inherent poor electrical conductivity and large volume expansion/contraction, Co3O(4)-carbon nanosheet hybrid nanoarchitectures were synthesized by a facile and scalable chemical process. However, it is still a challenge to control the size of Co3O(4) particles down to similar to 5 nm. Herein, we created nanosized cobalt oxide anchored 3D arrays of carbon nanosheets by the control of calcination condition. The uniformly dispersed Co3O(4) nanocrystals on carbon nanosheets held a diameter down to similar to 5 nm. When tested as anode materials for lithium-ion batteries, high lithium storage over 1200 mAh g(1) is achieved, whereas high rate capability with capacity of about 390 mAh g(1) at 10 A g(1) is maintained through nanoscale diffusion distances and interconnected porous structure. After 500 cycles, the cobalt oxide-carbon nansheets hybrid display a reversible capacity of about 970 mAh g(1) at 1 A g(1). The synergistic effect between nanosized cobalt oxide and sheetlike interconnected carbon nanosheets lead to the greatly improved specific capacity and the initial Coulombic efficiency of the hybrids.