Synthesis And Performance Of Cooper-based Nano-materials For Supercapacitors

The rapid development of renewable energy makes a increasing of energy storage devices gradually.Supercapacitors(SCs)have become one of the development directions of future energy technology because of its high power density,long cycle life and rapid charge-discharge ability.The electrode materials directly determine the charge storage capacity of the capacitor,which is an important factor about the supercapacitors.Therefore,it is of great significance to develop eco-enviroment,low cost and good performance electrode materials for the practical application of supercapacitors.In this paper,Cu(OH)₂/Cu₇S₄hybrid nanowires,Co-regulated Cu₇S₄ nanowires and Cu Co₂O₄nanoparticles were prepared by facile synthesis.The electrochemical properties of the single electrode of these electrode materials were also studied.A hybrid supercapacitor(HSC)device was composed of a positive electrode with above materials and an active carbon(AC)negative electrode.The electrochemical performance of the HSC was studied and the effect of long-term cycling was tested.The main work research are as follows:(1)[Cu(tu)]Cl·1/2H₂O nanowire precursors were prepared by chemical precipitation method at room temperature,and Cu(OH)₂/Cu₇S₄ porous hybrid nanowires were directly sythesis by self-sacrificial template method.Cu(OH)₂/Cu₇S₄ has a large specific surface area(102.8 m²/g)and pore volume(0.2879 cm³/g)as well as a significant specific capacitance without any conductive agent and binder which reach the high 1610.8 C/g when the current density is 4 A/g.The hybrid supercapacitor composed of activated carbon and Cu(OH)₂/Cu₇S₄ has high energy density,power density(48.1Wh/kg,429.3W/kg)and good cycle stability.The excellent electrochemical performance is mainly attributed to the synergistic effect of Cu(OH)₂ and Cu₇S₄,the structure of Cu(OH)₂/Cu₇S₄ porous hybrid nanowires,as well as the large specific surface area and pore volume which make it possible to have a broad application prospect as high-performance supercapacitor.(2)The precursor was prepared by chemical precipitation at room temperature,and sulfuration with self-sacrificial template method under the control of different cobalt ion co ncentration.Then Cu₇S₄ nanowires was systhesised.The specific capacitance of1302.0 C/g(4 A/g)which far higher than the without cobalt ions control samples(681.6C/g).Moreover,at a high current density(40 A/g),the specific capacitance remains61.8%.With Cu₇S₄ nanowires as the positive electrode and AC as the negative electrode,the HSC device has an excellent energy/power density(39.3Wh/kg,20393.26W/kg),and a stable cycle performance.It has no attenuation when charged and discharged 20000times at 5 A/g and 20 A/g,respectively.(3)Cu Co₂O₄ nanoparticles were successfully synthesized by co-precipitation method and futher annealing treatment,which had the advantages of small volume,large specific surface area,large pore volume,abundant active sites,high specific capacity and good rate performance.In the process of charging and discharging performance,type of energy storage is surface capacity,with battery type behavior of diffusion controlled process.The power density of Cu Co₂O₄-250//AC HSC is 832.6 W/kg,and 29.5 Wh/kg of high energy density.After 10000 times charging and discharging cycles,the capacity remain 72.7%,showing the good cycle stability.