A high energy asymmetric supercapacitor based on flower-like CoMoO₄/MnO₂ heterostructures and activated carbon

Flower-like CoMoO₄/MnO₂ heterostructures have been prepared directly on Ni foam with outstanding pseudocapacitive performance. The heterostructure electrode yields a high capacitance and superior cycling stability performance. Furthermore, the as-fabricated asymmetric supercapacitor device based on CoMoO₄/MnO₂ positive electrode and activated carbon (AC) negative electrode can operate within a maximum potential of 1.6 V delivering both high energy density and power density, which are better than that of the CoMoO₄//AC, MnO₂//AC, and AC//AC bared density. In addition, the CoMoO₄/MnO₂//AC asymmetric supercapacitor device demonstrates highly stable cyclic performance with outstanding and robust flexibility. These encouraging results show great potential in developing energy storage devices by building heterostructure nanomaterials.