Synthesis and electrochemical application of graphene - manganese novel dioxide composite
Cui, Xiaojia (2021)
Cui, Xiaojia
2021
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2021082017064
https://urn.fi/URN:NBN:fi:amk-2021082017064
Tiivistelmä
The supercapacitor is a new type of energy storage element. Compared with traditional batteries and capacitors, it has better electrochemical performance, cleanness and environmental friendliness, and has great application potential in many fields. Therefore, supercapacitors have attracted more and more attention.
In this paper, we report a quick and simple method to prepare graphene -MnO2 composite as a new electrode material by microwave irradiation. For this composite material, graphene nanosheets are mainly used as highly conductive carriers, which can also provide a larger specific surface area for depositing MnO2 particles. Due to the high conductivity of graphene, outstanding interface contact and increased contact area between graphene and MnO2, conductivity of the electrode can be significantly improved. In addition, due to the high specific surface area of the composite, the electrolyte solution can easily enter the surface of the composite, and the electrochemical utilization efficiency of MnO2 is improved, which can not only provide high reversible pseudo-capacitance, but also provide excellent capacitance retention. Through SEM, CV and EIS test, it is found that the specific capacitance of the composite is 455 F/g at 1 A/g and 416 F/g at 5 A/g, and the capacitance retention rate is 91.4%, which means excellent electrochemical performance. The enhanced high-rate electrochemical performance is due to the increase of electrode conductivity in the presence of graphene network, effective interface area between MnO2 and electrolyte and the increased contact area between MnO2 and graphene.
In this paper, we report a quick and simple method to prepare graphene -MnO2 composite as a new electrode material by microwave irradiation. For this composite material, graphene nanosheets are mainly used as highly conductive carriers, which can also provide a larger specific surface area for depositing MnO2 particles. Due to the high conductivity of graphene, outstanding interface contact and increased contact area between graphene and MnO2, conductivity of the electrode can be significantly improved. In addition, due to the high specific surface area of the composite, the electrolyte solution can easily enter the surface of the composite, and the electrochemical utilization efficiency of MnO2 is improved, which can not only provide high reversible pseudo-capacitance, but also provide excellent capacitance retention. Through SEM, CV and EIS test, it is found that the specific capacitance of the composite is 455 F/g at 1 A/g and 416 F/g at 5 A/g, and the capacitance retention rate is 91.4%, which means excellent electrochemical performance. The enhanced high-rate electrochemical performance is due to the increase of electrode conductivity in the presence of graphene network, effective interface area between MnO2 and electrolyte and the increased contact area between MnO2 and graphene.