Characterization of porous micro-/nanostructured Co3O4 microellipsoids

•Porous Co3O4 microellipsoids are obtained by a facile method.•The initial discharge capacity of as-prepared Co3O4 is 1314 mAh g−1 at 100 mA g−1.•Excellent rate capabilities are observed for the porous Co3O4 microellipsoids.•Porous Co3O4 microellipsoid shows enhanced cyclic stability.

The porous micro-/nanostructured Co3O4 microellipsoids are successfully fabricated through a urea-assisted solvothermal route using polyvinylpyrrolidone (PVP) as the capping reagent followed by thermal treatment in air. The porous characterization has been performed to confirm that porous Co3O4 micro-/nanostructures are composed of numerous primary nanocrystallines. The specific surface area and pore size of the Co3O4 microellipsoids are around ∼24.2 m2 g−1 and 13.5 nm, respectively. The obtained porous Co3O4 microellipsoids demonstrate the high initial discharge capacity of ∼1314 mAh g−1 with a Columbic efficiency of 79.2% at a current density of 50 mA g−1 in the potential range of 0.01–3.0 V. More impressively, a significantly improved reversible capacity of ∼1192 mAh g−1 is retained at 100 mA g−1 after 50 discharge-charge cycles. Excellent rate capabilities (∼920 mAh g−1 at 200 mA g−1 and ∼630 mAh g−1 at 600 mA g−1) are observed for the porous microellipsoid-like structure. It should be noted that the unique porous micro-/nanostructured microellipsoids play an important role in the enhanced electrochemical lithium storage performance. Therefore, the porous micro-/nanostructured Co3O4 microellipsoids should be suitable as an anode material for lithium ion batteries.

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