A facile strategy for fabricating hierarchically mesoporous Co3O4 urchins and bundles and their application in Li-ion batteries with high electrochemical performance

Abstract

Herein, we report a facile template- and surfactant-free strategy for the fabrication of 3D hierarchically mesoporous Co₃O₄ urchins and bundles, which involves a subsequent heat treatment of the corresponding novel precursors at 400 °C in air for 4 h. The morphology evolution mechanism of the precursor was revealed through systematic time- and temperature-dependent experiments. The as-synthesized mesoporous Co₃O₄ urchins and bundles deliver an enhanced lithium storage capacity, good cycling stability and excellent rate capabilities (e.g., 781 mA h g⁻¹ for Co₃O₄ urchins and 660 mA h g⁻¹ for Co₃O₄ bundles at 2 A g⁻¹), indicating their potential applications in high power lithium ion batteries. The improved electrochemical performance is mainly attributed to the 3D structure and numerous mesopores within the nanofibers and nanosheets, which can effectively enhance structural stability, provide efficient diffusion length for lithium ions and electrons, and buffer volume expansion during the Li⁺ insertion/extraction processes.