Research And Application Of Electrolytic Preparation Of High-conductivity Copper Powder

Dendritic copper powder is mainly a kind of metal powder prepared by electrolysis method,and its microscopic morphology is mostly dendritic.Due to its special morphology,it has a large specific surface area and low resistance,so it is widely used in shielding materials,batteries,aerospace and other special fields.However,copper powders usually prepared by electrolysis have some defects,such as serious agglomeration,thick dendrite,large thickness of the film material and the inability to form good conductive network,which limit the wide application of dendritic copper powders in conductive film materials.To solve this problem,on the basis of preparing copper powder by conventional electrolysis method,by using additives and changing the electrolysis parameters,the dendritic powders with slender micro-morphology,well-branched,good conductivity and relatively small thickness were successfully obtained.By X-ray diffraction(XRD),scanning electron microscopy(SEM),electrochemical workstation,specific surface area analyzer,etc.,the prepared electrolytic copper powder was characterized,and the effects of different additives and process strips on the microstructure and properties were studied.The experimental results show that:(1)In sodium dodecyl sulfate is added to the electrolyte(SDBS)and polyvinylpyrrolidone(PVP),can be prepared microstructure of long and thin and has developed the branches of the copper powder,SEM/EDS and XRD analysis showed that powder purity is high,the copper powder dendrite slender branches thick,good dispersibility,low apparent density and high specific surface area,can form good conductive network,and the film thickness is relatively small.(2)The effect of different process conditions on the micro-morphology of The electrolytic copper powder was explored.The results showed that the current density was 1500A/m²,the Cu²⁺concentration was 0.01mol/L,the H₂SO₄ content was0.25mol/L,and the additive SDBS and PVP content were 5g/L,respectively,1.25g/L and the scraping cycle is 25min,the dendritic shape of the metal powder is obvious,the main branch is branched and slender,the particle size is uniform,and the morphology is the best.(3)The synergistic effect of additive PVP and SDBS plays an important role in improving the morphology and properties of electrolytic copper powder.And did not join or separate only to join PVP or SDBS,compared to one of the additives in the electrolyte and add a certain amount of PVP and SDBS,cathode has higher Cu2+reduction reaction impedance,lower diffusion resistance and increase the cathodic polarization and diffusion and mass transfer effect,which is beneficial to improve the crystallization nucleation rate of copper,lower growth rate,which is easy to obtain fine grain copper powder.It ensures that the ions have greater cathodic polarization in the case of high mass transfer effect and high dispersion.This behavior can be attributed to the formation of micelles between SDBS and PVP,which can occupy the active site of cathode reaction and hinder the reduction and precipitation of Cu2+,resulting in negative potential shift of electrolytic copper powder and increase of cathode polarization.(4)The addition of additives can reduce the activation energy needed for atomic diffusion and increase the transfer rate and dispersion degree in the reaction process.The order of influence is as follows:(SDBS+PVP)>SDBS>PVP>Blank.(5)The bulk density of dendritic copper powder prepared by experiment is0.567 g·cm^-3,the specific surface area is 3.543 m²·g,and the resistance is 15 m?.