Executive Summary : | Great efforts have been made to develop the high efficient electrode materials with enhanced ionic/electronic transport properties with commercial level mass loading up to 10 mg/cm2 with ultra-thick for supercapacitors application. However, the electrodes with commercial-scale mass loading limit the electron/ion transfer which causes capacity degradation at a fixed potential window due to the overpotential. Therefore, we proposed a new method for the synthesis of porous 3D graphene-based carbon electrodes with superior ionic/electrical conductivity at commercial scale mass loading, which leads to better gravimetric capacitance. Co-PI has established the electrospray coating facility under the DST-INSPIRE project (DST/INSPIRE/04/2018/001444) for the fabrication of carbon nanodots based flexible electrodes for supercapacitor applications. Moreover, we proposed to construct an electrically triggered Jole heating set-up with an ultrafast high-temperature measurement system using an optical fibre-based spectrometer. Therefore, we planed to exploit both (Electrospray and Joule heating) techniques for the synthesis of porous 3D graphene-based carbon electrodes from carbon nanoparticles (CNs) with commercial mass loading. In the proposed work, The Electrospray technique will be used for coating mesoporous CNs film on a flexible carbon substrate. The parameters like liquid flow rates and applied voltage at the nozzle of the electrospray setup will be optimized to have a mesoporous film with high mass loading of CNs. And then Joule heating experiment will be performed to obtain flexible porous 3D graphene-based carbon electrodes with desired geometrical structures at commercial scale mass loading. The mechanism behind the formation of the 3D porous continuous network from CNs is the formation of covalent bonding between the adjoined CNs and then graphitization at a high temperature (More than 2500 K) and an ultra-fast rate (~200 K/minute)during Joule heating. The degree of graphitization can be optimized by the pulse width and time duration DC power supply. The temperature at the reaction spot will be measured as the function of the applied current (mA to A) and time (ms), using the temperature measurement system to identify the optimum conditions for obtaining a porous 3D graphene-based carbon network with high electrical/ionic conductivity. The relation between geometrical structures ( porosity, thickness of the film, and mass loading) and electrochemical properties of electrodes will be studied in 3-electrode configurations. Finally, we proposed to construct the flexible compact supercapacitors and studied their electrochemical properties. |