Font Size: a A A

Study On The Synthesis And Properties Of Supercapacitors Based On The Nickel Loaded Carbon Foam Electrode Material

Posted on:2018-07-04Degree:MasterType:Thesis
Country:ChinaCandidate:G Q JiangFull Text:PDF
GTID:2322330533970008Subject:Materials engineering
Abstract/Summary:PDF Full Text Request
Due to the advantages that high power density,long cycle stability,rapid charge Supercapacitor is a device used to store and convert energy.It has a high power density,fast charge and discharge and the most important environment and other characteristics.These characteristics make it have an important and wide application prospects.Among the many decisive factors in the performance of supercapacitors,the choice of electrode materials and the performance improvement are particularly important.At present,according to the different reaction mechanism classification,the electrode material divides into two kinds,one to provide electric double layer capacitor,the other to provide pseudo-capacitance.In the first double electric layer electrode material,there are many studies on the carbon material,it has good chemical stability,conductivity and high specific surface area and other advantages,while the double layer is mainly dependent on the surface of the material to provide specific,so the level of surface area is an important factor in determining the level of electric double layer capacitance,but only rely on the surface of the electrode material is very limited;the second is to use the Faraday oxidation reduction reaction to provide the Capacitors,the main matermails are transition metal oxides or hydroxides.They have a much higher specific capacitance than carbon materials,but the application of this electrode material in practice is limited because of their low conductivity and poor cycle stability.How to make up for the shortcomings of the two electrode materials and maximize the advantages of both are the challenges of the current super capacitor electrode materials and the urgent problemto solve.In order to solve the above problems,this paper will have melamine foam and transition metal nickel composite,and the melamine foam have a high specific surface area and good conductivity.through the synergy between the two materials,not only can improve the conductivity of composite materials,but also can improve the structure and electrochemical properties of the electrode materials.At the end,The effect of the acid solution to the structure and electrochemical properties of the electrode materials is studied in this paper.Firstly,melamine foam was prepared by simple heat treatment carbonization and inert gas protection.Melamine carbon foam was rich in pore structure after high temperature heat treatment.The pore size range was about 20-50?m,the skeleton diameter was about 3.20?m.It also have a better strength and flexibility,but the capacitance is very small.Therefore,We use the physical filling method in the raw material melamine foam to filled with a certain mass ratio of nickel powder(particle size 150 nm),and then carbonization treatment.The results of carbonization treatment show that the carbon skeleton have a certain degree of damage and fracture,and nickel powder have a certain degree of reunion.with the carbonization temperature increases,the fracture and agglomeration will increase.When a small amount of nickel powder is loaded,the nickel is almost uniformly distributed on the carbon foam,and when a large amount of nickel powder is loaded,the carbon foam melts on the surface of the agglomerated nickel.As the temperature increases,the defects become more and more.The electrochemical performance of the samples with the highest carbonization temperature of 700? and the mass ratio of C: Ni was 1:10 was better.At the current density of 0.02 A/cm2,the specific capacitance reached 6.1 F/cm2.in the cyclic voltammetry test,the specific capacitance can reach 3.79 F/cm2 when the sweep speed of 5 mV/s.In this paper,the prepared materials were subjected to hydrochloric acid soaking to investigate the effect of hydrochloric acid soaking time on the properties of the prepared electrode materials.Hydrochloric acid soaking to produce a large amount of gas on the surface of the electrode material,and the solution followed by green.The structure of the material does not change.EDS characterizes that carbon and nickel content remained essentially unchanged.The electrochemical test results have a large degree of rise When the soaking time is 2h.At the current density of 0.01 A/cm2,the specific capacitance can reach 6.25 F/cm2(0.77 F/cm2 before immersion).In the cyclic voltammetry test,the specific capacitance can reach 3.44 F/cm2(1.04 F/cm2 before soaking)When the sweep speed is 5 mV/s.So the hydrochloric acid soaking makes the specific capacitance of the electrode material greatly improved.In summary,the nickel-supported carbon foam is a class of excellent supercapacitor electrode material and has a great performance improvement space.
Keywords/Search Tags:supercapacitor, electrode material, carbon foam, nickel-supported
PDF Full Text Request
Related items