In situ removal of template to synthesize mesoporous NiCo2O4 for high performance battery-type electrode

- Mesoporous NiCo2O4 with a large specific surface area of 219.2 m2 g− 1 is prepared.
- The in situ removal of template synthesis route under normal atmospheric is facile.
- The sample shows a high specific capacitance of 660.53 C g− 1 at 1 A g− 1.
- NiCo2O4 electrodes still remain 90% specific capacity retention over 32,000 cycles.

In this work, mesoporous NiCo2O4 has been successfully synthesized by in situ removal of template method. The NiCo2O4 composite was precipitated by hydrolysis method using ethylene glycol as a high boiling point solvent at 140 °C under atmospheric environment. Zinc hydroxide is used as the sacrificial template to construct the mesoporous structure with high specific surface area. The structure and morphology characteristics were carried out by X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, and N2 adsorption experiments. The electrochemical properties were investigated through AC impedance spectroscopy, cycling voltammetry and charge/discharge test in 7 M KOH. The results exhibit that the as-prepared mesoporous NiCo2O4 shows a large specific surface area of 219.2 m2 g− 1, a high specific capacity of 660.53 C g− 1 at current density of 1 A g− 1. The mesoporous NiCo2O4 electrodes still remain 90% specific capacity retention compared with the first cycle over 32,000 cycles, which exhibits the as-prepared electrode possess long-term stability.