Supercapacitor Of Carbon-based Composite Film For Wide Frequency Band Filtering

With the development of science and technology and the improvement of human needs,electronic products tend to be simplified,miniaturized,and integrated.Electrical signals of different frequencies are common in electronic circuits.In order to obtain a stable DC voltage,a capacitor that can filter stably in a wide frequency range is needed to process it(in the following,this kind of capacitor is called"frequency band filter capacitor").At present,the most commonly used frequency band filter capacitors are the large-capacity aluminum electrolytic capacitors(AEC),but the volume and parasitic inductance of the aluminum electrolytic capacitors are too large,which severely limits the application of aluminum electrolytic capacitors in microelectronic devices and the effective filter frequency band width.Notably,supercapacitors(SCs)have larger specific capacitance,small size and low parasitic inductance.Therefore,compared to aluminum electrolytic capacitors,supercapacitors may be more suitable for use as frequency band filter capacitors.The application and performance optimization of supercapacitors in wide frequency band filtering have great research significance,but there are still few researches on supercapacitors in wide frequency band filtering.The purpose of the research in this article is to develop a supercapacitor with small size and stable filtering in a wide frequency range.This article first introduces the experimental method,that is,a carbon-based composite film electrode containing carbon nano onion,activated carbon and graphene is prepared by thermal decomposition and chemical vapor deposition,and then assembled into a supercapacitor(carbon nano onion has good surface accessibility and low parasitic inductance,so that the supercapacitor has good frequency characteristics under high frequency conditions;the high specific capacitance characteristics of activated carbon under low frequency conditions ensure the excellent low frequency filtering effect of supercapacitors;graphene connects activated carbon and carbon nano onion and acts as an intermediate conductor to effectively reduce the internal resistance of the electrode).Then the electrochemical impedance spectroscopy test and performance analysis of the supercapacitor show that the supercapacitor has a capacitance value of up to 5.34 m F and an area specific capacitance of up to 4.73 m F cm^-2(in the frequency range of 1?100 k Hz),and the self-resonant frequency is as high as 101360 Hz.Finally,install a single supercapacitor into the linear voltage regulator circuit to test the actual filtering effect.The results show that the supercapacitor has an excellent and stable filtering effect in the frequency range of 1?100 k Hz,and its volume is smaller than aluminum electrolytic capacitors.The test results in this paper strongly prove the excellent performance of carbon-based composite film supercapacitor in wide frequency range filtering and the feasibility of using small-volume supercapacitors to replace large-volume aluminum electrolytic capacitors.This research has important implications for the development of future integrated electronic devices.