Mesoporous nano-Co3O4: A potential negative electrode material for alkaline secondary battery

A potential negative electrode material (mesoporous nano-Co3O4) is synthesized via a simple thermal decomposition of precursor Co(OH)2 hexagonal nanosheets in the air. The structure and morphology of the samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is found that the nano-Co3O4 is present in mesoporous hexagonal nanoparticles. The average size of holes is about 5–15 nm. The electrochemical performances of mesoporous nano-Co3O4 as the active starting negative electrode material for alkaline secondary battery are investigated by galvanostatic charge–discharge and cyclic voltammetry (CV) technique. The results demonstrate that the prepared mesoporous nano-Co3O4 electrode displays excellent electrochemical performance. The discharge capacity of the mesoporous nano-Co3O4 electrode can reach 436.5 mAh g−1 and retain about 351.5 mAh g−1 after 100 cycles at discharge current of 100 mA g−1. A properly electrochemical reaction mechanism of mesoporous nano-Co3O4 electrode is also constructed in detail.

► Mesoporous nano-Co3O4 is hexagonal nanoparticles with the average size around 100 nm. ► The average size of holes is about 5–15 nm. ► Mesoporous nano-Co3O4 as the negative material for alkaline secondarybattery for the first time. ► The discharge capacity of the mesoporous nano-Co3O4 reached 436.5 mAh g−1. ► The capacity after 100 cycles was still 351.5 mAh g−1.