Biomass-derived Three-dimensionally Interconnected Porous-carbon Electrode For Supercapacitors

Tesla,Shanghai super capacitor bus,fast charging,the recent emergence of the new terms show people's broad interests of the energy storage and energy conversion research.Supercapacitor with high power density,long cycle life,and low cost energy efficiency is considered to be a promising storage.In line with the principle of protection of the environment and reduce costs,In order to obtain high specific capacitance,good cycle life supercapacitor materials,the group seeks to material nature,trying to use graphitization biological template prepared preferably porous carbon or low cost graphene.Experiment divided into two parts,the first part is the preparation characterization and testing of Enteromorpha template supercapacitor electrode materials: In order to obtain high specific capacitance,good cycle life supercapacitor materials,enteromorpha was selected as carbon source,then a high temperature carbonization was used to prepared 3D-Fiberbased carbon?abbreviation: C?,at last the Hydrothermal method was chose to prepared MnO/C composite materials?abbreviation: MCs?.The results show that: due to the good spatial structure,the 3DFiberbased carbon exhibits an excellent BET-surface area of 180 m2·g-1.MCs are featured with a 3D conductive network structure,and metal oxide particles between the graphene sheets grow evenly,about 30 nm in diameter.The results of Electrochemical test show that: in 0.5 mol·L-1 Na₂SO₄ solution,at a current density of 1 A·g-1,when the load at 80%,the MCs exhibit an excellent capacitance of 218.2 F·g-1.Meanwhile,the MCs also show cycling stability with 79.6% of the capacitance retention after 1000 cycles of charge/discharge.This result did not achieve the desired targets,so the second part of the experiment expanded: In order to obtain high specific capacitance,good cycle life supercapacitor materials,watermelon flesh was selected as carbon source,then a two-step carbonation was used to prepared 3D-Fiberbased graphene?abbreviation: G?,at last the Hydrothermal method was chose to prepared CeO₂-MnO/G composite materials?abbreviation: CMGs?.The results show that: due to the good spatial structure,the 3DFiberbased graphene exhibits an excellent BET-surface area of 332 m2·g-1.CMGs are featured with a 3D conductive network structure,and metal oxide particles between the graphene sheets grow evenly,about 10 nm in diameter.The results of Electrochemical test show that: in 0.5 mol·L-1 Na₂SO₄ solution,at a current density of 1 A·g-1,when Ce⁴⁺:Mn²⁺=1:4 and the composite load at 80%,the CMGs exhibit an excellent capacitance of 308.5 F·g-1.Meanwhile,the CMGs also show outstanding cycling stability with 95.5% of the capacitance retention after 1000 cycles of charge/discharge.The high electrochemical properties of the CMGs is mainly because the synergy of two metal oxide composite load with graphene.At the same time,the photocatalytic degradation experiment and the methylene blue adsorption experiment were did to detect the sample's performance.The results show that: TOC removal rate is 83.25%,methylene blue adsorption rate reached 98.2% after 20 h in 160 mg·L-1 methylene blue solution.