Intrinsic performance regulation in hierarchically porous Co3O4 microrods towards high-rate lithium ion battery anode

Abstract

The hierarchically porous Co3O4 microrods made up of orientated self-assembled nanorods are fabricated through a facile strategy, which possess bicontinuous mesopores and one dimensional macropores. Oxygen vacancies are successfully introduced into Co3O4 microrods by simply controlling the heating temperature. When applied into lithium ion batteries as anode materials, local in-plane electric fields induced by the introduced oxygen vacancies and hierarchically bicontinuous porous feature endow Co3O4 microrods with enhanced ionic and electronic conductivity, outstanding structural stability and good electrochemical (de)lithiation reversibility. As a result, a high reversible capacity of 1858 mA h g−1 after 300 cycles at 0.5 A g−1 and distinguished high-rate long-term cycling stability with a specific capacity of 502 mA h g−1 after total 1000 cycles at 5 A g−1 are delivered. The magnetic hysteresis loops, zero-field cooled and field-cooled temperature-dependent magnetization curves after different cycles are used to explore the electrochemical reaction reversibility and structural stability of electrode materials. The result highlights the importance of the intrinsic performance regulation of atomic defects, morphology, microstructures and pores structure of anode materials on the improvement of their ionic and electronic conductivity, structural stability and thus electrochemical properties.