Integral-Type Porous Cobalt@Cobalt Oxide Anode with Micro/Nano-Sized Pores for Lithium-Ion Battery

Abstract

The integrated porous Cobalt@Cobalt oxide anode was prepared by facile processes including freeze-casting and thermal-oxidation for use as high-capacity anode material of lithium-ion battery. The three-dimensional Co foam with elongated, aligned micropores was synthesized by a freeze-casting process. Subsequently, it was heat-treated in order to form cobalt oxide material with nano-structure on the surface of the Co foam. In this electrode design, the hierarchical three-dimensional Co foam was used as current collector and nanowall-like cobalt oxide layer acted as anode that reacts with lithium ions during discharging and charging. The integrated porous Cobalt@Cobalt oxide anode exhibits highly reversible capacity of 1200 mAhg -1 even after 45 cycles with an initial coulombic efficiency of 79.1%, which is much higher than that of the conventional cobalt foil anode (259 mAhg -1 ). The integrated porous Cobalt@Cobalt oxide anode, which was fabricated in this study, has promising potential applications as a self-supporting advanced anode architecture with high capacity for lithium-ion battery.