3D hierarchical Co3O4 microspheres with enhanced lithium-ion battery performance

Abstract

Although transition metal oxide electrodes have large lithium storage capacity, they often suffer from low rate capability and poor cycling stability. To develop an electrode with a long cycle life and good rate capability, 3D hierarchical tricobalt tetraoxide (Co₃O₄) spheres are fabricated under various hydrothermal conditions and evaluated as an anode in lithium-ion batteries. 3D hierarchical urchin-like Co₃O₄ electrodes exhibit a high reversible discharge capacity, excellent rate capability and good cycling performance, owing to their hierarchical architecture composed of micro-/nanostructures. Electrochemical testing shows that stable reversible capabilities of 1228 and 820 mA h g⁻¹ can still be maintained after 170 cycles at 200 and 500 mA g⁻¹, respectively. After rate capacity performance measurements, even the current density is increased to 3200 mA g⁻¹ and a capacity of 587 mA h g⁻¹ is retained after 500 cycles. The unique 3D hierarchical urchin-like Co₃O₄ electrode facilitates lithium ion diffusion and electron transportation and mitigates the internal mechanical stress induced by the volume variations of the electrode upon cycling, which lead to outstanding electrochemical performance.