Needle-like CoMoO with multi-modal porosity for pseudocapacitors

The needle-like Co Mo O 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 Co Mo O 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 Co Mo O 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 MoO 3 in the needle-like Co Mo O 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 Co Mo O and thus indirectly affect the electrochemical performance of the needle-like Co Mo O.