Abstract:
Electric Double Layer Capacitors (EDLC) are used in various energy storage applications such as hybrid vehicles, ultra fast charging smartphones and knitted electronics among other applications. They have also been used in combination with batteries to increase energy and power density. Extensive work has been done to understand the working mechanism of EDLC and effects of electrode and electrolyte material are well understood.
In this work we study the effects of EDLC design on capacitance of flexible laser scribed interdigitated microsupercapacitor (LSG-MSC). Three design parameters are tested to understand the effects of each on total capacitance. These parameters are: (1) current collector-electrode interaction, (2) electrode aperture and (3) distance between parallel electrodes. Detailed analysis was presented for the change in capacitance using cyclic voltammetry, electrochemical impedance spectroscopy and electrostatic simulation using COMSOL Multiphysics. It was found that in addition to electric double layer capacitance, there was also electric field being generated (i) between electrodes and (ii) between electrodes and current collector which lead to small electrostatic capacitance between them. This electric field was also found to cause disturbance in the double layer formation at the electrode thus causing change in the overall capacitance as the design parameters of the MSC were varied.
