Mycelium As A Template To Synthesize Cerium Manganese Oxide- Graphene Composite And Properties Of Super Capacitors Research

With the development of society, the demand of energy storage devices used in portable electronic devices and electric vehicles is increasing. Supercapacitor is a storage device between the capacitor and the rechargeable battery, which has a higher energy storage density, longer the cycle life, lower maintenance costs and faster charging and discharging ability. It can be widely used in products required fast charging such as electric vehicles, consumer electronics, medical equipment and others. There are three common types electrode material used in super-capacitor: carbon-based materials, metal oxides, conductive polymers. The carbon-based material is the core material of a super-capacitor. Traditional carbon material couldn’t be used to meet demand because there are many closed pores in the, and it has large resistance, low capacitance and other shortcomings. It could not be realized that make carbon nanotubes production cause its high expense. But it can be solved by graphene, and it has been found that graphene with a curly structure appeared better capacity to store charge.This paper attempts to cultivate mycelium with long tube structure to prepare high-quality multi-walled graphene tube in a very simple way. In order to improve the energy density of the graphene electrode and avoid the loss of electrode, MnO2 and CeO2 with dissimilar lattice type were used while growing. It can also reduce instability of the cycle life during metal oxide the repeated charge-discharge. The morphology and microstructure of the as-prepared composite was characterized by XRD, SEM, Raman, AFM, FT-IR, TEM and N2 adsorption-desorption isotherms. And Constant current charge-discharge, cyclic voltammetry is used to study the electrochemical properties of graphene matrix composite electrode.The results showed that mycelium could be used to prepare graphene tubes with high performance under tube furnace in 700 ℃ heat by nitrogen protection for 100 min. The specific surface area of the prepared material graphene tubes was up to 385.4 m2/g. It was about 4-5 layers. Its specific capacitance could be 295 F·g-1 when MnO2 was added. The CeO2 was doped into MnO2 to generate ultrafine nanoparticles, and the size of nanoparticales was only 10 nm or less. The graphene- cerium manganese composite material was made with nanoparticles loading on graphene tube uniformly. By Cyclic Voltammetry and galvanostatic charge-discharge tests, it has showed that prwpared materials had superior specific capacitance performance to ordinary carbon powder. The specific capacitance was 400 F·g-1, more than 26 F·g-1. Experimental results has showed that the graphene composite materials could be used to prepare high-performance supercapacitor.