Needle-like CoMoO with multi-modal porosity for pseudocapacitors

The needle-like CoMoO with multi-modal porosity was synthesized via simple strategy of chemical coprecipitation in hydrothermal condition. The resulted products were characterized with SEM, EDXS, XPS, XRD, Raman, BET, FTIR and electrochemical techniques. The needle-like CoMoO exhibited excellent electrochemical performance as supercapacitor. A large capacitance value of 1180 F/g was obtained with good cycle life from the CV plots at 5 mV/s or 302 F/g was calculated from the discharge curve at 1 A/g. The good electrochemical performance may be attributed to the multi-modal microstructure of the needle-like CoMoO with the combination of microporosity, mesoporosity and macroporosity which leads to the large surface area and the excellent contact probability, diffusion efficiency and storage ability of OH− ions. It's observed for the first time that MoO3 in the needle-like CoMoO gradually flows away with the charge-discharge. The presence of Mo may not directly contribute to the electrochemcal capacitance of the materials but it helps to form the structure of the obtained needle-like CoMoO and thus indirectly affect the electrochemical performance of the needle-like CoMoO.