Rational construction of CoO/CoF2 coating on burnt-pot inspired 2D CNs as the battery-like electrode for supercapacitors

Having a burnt pot is bothersome in the kitchen, and the carbonized food on it is difficult to clean. Here, burnt starch, which has the advantage of being mechanically robust, was utilized as the carbon material for energy storage applications. Interestingly, 2D amorphous carbon nanosheets (CNs) could be synthesized by simply burning corn starch above a Ni foam. By further coating a CoO/CoF2 composite film onto the CNs, the hybrid electrode exhibited significant improvement in terms of electron collection efficiency. Benefiting from the synergistic effect of the Co compounds and CNs, the synthesized electrode demonstrated high specific capacitance (12.00 F cm(-2) at a current density of 5 mA cm(-2)), excellent rate capability, and superior cycling stability. Furthermore, three connected symmetric supercapacitors were able to power LED lights for more than 10 min. Therefore, this work provides a new strategy for the fabrication of 2D CN and further applications in supercapacitors. (C) 2019 Elsevier B.V. All rights reserved.