Research And Development Of Micro-porous Copper Foil Preparation Equipment And Technology

Three-dimensional porous metal materials have a large specific surface area due to the presence of perforations in their interior,which have natural advantages in the fields related to medium transfer and reaction,especially in the battery manufacturing industry and the field of electrochemical reaction instruments.In recent years,the field of porous metal manufacturing has become the focus of scientific researchers,and the preparation technology of porous metal has been developed by leaps and leaps.Currently,there are many methods for the preparation of porous metal,such as template method,de-alloying method and 3D printing method.Compared with other common templating methods,the hydrogen bubble templating method has the characteristics of simple operation,green,convenient and no need to remove the templating material,which has attracted the attention of scholars.The hydrogen bubble template method is to precipitate a large number of hydrogen bubbles at the electrode cathode under the deposition condition of high cathode polarization.When the hydrogen bubbles are precipitated,the copper ions will also deposit on the cathode matrix where there is no hydrogen bubble.Finally,the porous metal film can be deposited using the hydrogen bubbles precipitated from the cathode as the template.In this paper,the three-dimensional porous copper foil was prepared by hydrogen bubble template method,the equipment platform for the preparation of micro-porous copper foil was built,and the micro-porous copper foil was characterized by scanning electron microscope(SEM)and other equipment.The technological parameters and additives which may affect the surface morphology and structure of porous copper foil were investigated.The main work is as follows:(1)by changing a single variable,the influence rules of basic solvents and electrical process parameters such as copper sulfate concentration,sulfuric acid concentration,current density and deposition time in electroprecipitation effusion were deeply explored.It was found that with the increase of copper sulfate concentration,the pore size on the surface of the microporous copper foil increased and the sedimentary layer became thicker.The increase of the current density will only increase the thickness of the sedimentary layer and has little effect on the pore size.The size of pore size and the thickness of sedimentary layer will become larger and thicker with the increase of deposition time.(2)upon completion of the basic variables,on the basis of the halogen elements and polyethylene glycol(PEG),and the effects of these two kinds of additives on deposition has carried on the exploration,after adding sodium bromide in heavy fluid because of the additionof bromide ions produced "bromide bridge" effect,makes the coating surface quality improved and closely flat porous copper foil and sediments are obtained,and the addition of sodium bromide increases the aperture.When polyethylene glycol is added alone,the phenomenon that contradicts the addition of sodium bromide can be obtained.The addition of polyethylene glycol can significantly reduce the pore size of the sedimentary layer,because of the inhibition effect of polyethylene glycol on the deposition of copper ions,and the polymerization of hydrogen bubbles is also affected.When polyethylene glycol and sodium bromide are added to the sediment,there will be a synergistic effect between the two.The pore size of the copper foil will not change much,but the surface quality of the sediment layer will be better improved and become more compact.(3)in order to further improve the quality of sediment,this paper also introduces the ultrasonic system by electrodeposition,by ultrasonic cavitation and stirring effect,to a certain extent promote the nucleation velocity of copper ions,make the copper crystal arrangement more closely,and the addition of ultrasonic also accelerates the cathode base hydrogen bubble overflow,further narrowed the sediments aperture size,eventually won the uniform aperture size and density of hole wall microporous sedimentary copper foil.The optimum process conditions obtained by the process test are: copper sulfate concentration of2.5mol/L,sulfuric acid concentration of 1.5mol/L,current density of 3A/cm2,deposition temperature of 25?,deposition time of 25 s,sodium bromide concentration of 25mmol/L,polyethylene glycol concentration of 200mg/L,ultrasonic power of 100 W,ultrasonic frequency of 42 KHz.Under this process parameter,it can be obtained that the microporous copper foil is evenly distributed,the pore size is distributed between 50-60 microns,and the thickness of the sedimentary layer is about 100 microns.As a simple,fast and feasible method for the preparation of micro-porous copper foil,the hydrogen bubble template method has certain significance for theoretical research and practical application in real life,and has great potential and application value in the field of porous metal manufacturing.