Synthesis And Application Of Nanometer Copper Sulfide Composite Electrode Material

Energy crisis and environmental pollution are two important issues which should be solved urgently.To solve these problems,more and more people focus on the research of the new energy storage device.As the electrode material of the energy storage device,copper sulfide is readily available and has ideal electrochemical properties.The homogeneous precipitation method and the chemical deposition method are used to synthesize the nano copper sulfide.Reaction conditions are screened in detail.Electrochemical properties of the product are tested.When the reaction temperature is 80 ?,the pH value of the reaction system is 8.5,the concentration of triethanolamine solution is 0.05 mol/L and the concentration of thiourea solution is 0.2 mol/L,the nano copper sulfide prepared by the homogeneous precipitation method shows the best property.When the scanning rate is 50 mV/s,the specific capacitance of the first cycle of the copper sulfide is 1902.7 F/g.However,the cycle performance of the copper sulfide is very poor.The specific capacitance of the first cycle of the copper sulfide synthesized by the chemical deposition method is 1702.9 F/g,but its cycle performance is still poor.So the copper sulfide is compounded with other substances to improve its cycle performance.Electrodeposited polypyrrole/copper sulfide composite and carbon-coated copper sulfide synthesized by vapor deposition method have the best cycle performance.When the scanning rate is 50 mV/s,the specific capacitance of the first cycle of electrodeposited polypyrrole/copper sulfide composite is 927.4 F/g.After 2000 cycles,capacitance retention rate of this composite is 76.1%.When the scanning rate is 50 mV/s,the specific capacitance of the first cycle of the carbon-coated copper sulfide is 1230.6 F/g.This composite is used in a lithium-ion battery half-cell.The first discharge capacity of the half-cell is 847.5 mAh/g at 0.1C.After 1000 times of charge and discharge at 0.5C,the capacity retention rate is 65.1%.Compared with the copper sulfide's cycle performance,the composite's cycle performance is improved significantly.