Research On Supercapacitor Electrode Materials Of Conductive Polyaniline And Its Composites

As a new type of energy storage device that has both the advantages of traditional capacitors and secondary batteries,supercapacitors have become one of the hotspots in the research of new energy and new materials in the world.Improve its key parameters.Polyaniline has become a popular material for scientific researchers due to its advantages,especially its high pseudocapacitance properties.However,the molecular chain of polyaniline is relatively rigid,and the interaction between the chains makes the polyaniline less soluble,which makes it difficult to process,which limits its wider application.As a doping acid,dodecylbenzene sulfonic acid has a very strong environmental stability and good solubility.As a doping acid,it can improve the solubility of polyaniline and be further prepared into a flexible film.Through in-situ polymerization method and structural characterization analysis and electrochemical performance test analysis,preparation and study of DBSA doping and aniline concentration on the performance of DBSA-PANI material.In addition to the low solubility,the expansion and contraction of polyaniline due to the volume change during the counter ion insertion/removal process must be considered,and the addition of nanofillers to polyaniline can greatly reduce this defect.Compounding PANI and MWCNT,combining the synergy of the two,high specific surface area,high conductivity,and long cycle life,etc.to improve this problem.However,the insolubility and poor dispersibility of carbon nanotubes in common organic solvents,water and polymer matrix are the main drawbacks.Using surface functionalization(such as-COOH)means can obtain high specific surface area,good Faraday redox reaction and improve compatibility.In this paper,functionalized MWCNT-COOH and pure MWCNT are compounded with aniline,respectively,and a more excellent composite electrode material is analyzed and compared.The amount of carboxylated carbon nanotubes incorporated is critical.If the amount is small,the overall performance of the composite material will be weakened;but if the amount is too large,the solubility of the entire system will increase.Therefore,the effect of the content of carboxylated carbon nanotubes on the performance of MWCNT-COOH/PANI composites was studied.Dodecylbenzenesulfonic acid doped polyaniline electrode materials were directly prepared by a simple emulsion polymerization method,and the effects of different aniline concentrations on the prepared DBSA-PANI supercapacitor electrode materials were studied.All DBSA-PANI materials prepared under different aniline concentrations have similar chemical structure,crystallinity,obvious pseudocapacitance behavior and lower solution resistance.When the concentration of aniline is low,PANI nanofibers exist as the main microstructure,and when the concentration of aniline is high,polyaniline agglomerates into irregular particles.The CV and GCD results show that when the aniline concentration is lower than 0.6 mol/L,the specific capacitance of the DBSA-PANI material increases with the increase of the aniline concentration,and the aniline concentration of 0.5 mol/L is the optimal concentration for preparation.EIS results confirmed that the higher the aniline concentration,the better the supercapacitor performance of DBSA-PANI.Secondly,using the same polymerization method on the basis of the optimal concentration,the effects of two other factors,APS/aniline molar ratio and DBSA/aniline molar ratio,on DBSA-doped PANI electrode materials were studied.All DBSA doped PANI electrodes have similar chemical structure and crystallinity.When the APS/aniline molar ratio is 1.5 and the DBSA/aniline molar ratio is 0.1,the material structure shows nanofibers,with higher specific capacitance and smaller transfer resistance,the better the capacitance performance.Based on the research of the optimal polymerization conditions for the preparation of DBSA-PANI,MWCNT/PANI and MWCNT-COOH/PANI composite materials were prepared by a simple in-situ polymerization method.The micro-morphology,chemical structure,and electrochemical properties of the two composite materials Wait for a systematic comparison.The morphology of the MWCNT-COOH/PANI composite shows that,due to the growth of PANI on the surface of MWCNT-COOH,MWCNT forms a uniform interpenetrating network structure in the PANI matrix;the introduction of carboxyl groups changes the chemical structure of the composite.The electrochemical test results show that the MWCNT-COOH/PANI composite material has good oxidation/reduction performance at high current density.At a discharge current of 1 A/g,the MWCNT-COOH/PANI composite electrode showed a higher specific capacitance of 58.3 F/g,and the MWCNT/PANI composite material was 40.9 F/g.It can be attributed to the interpenetrating network structure of MWCNT-COOH/PANI composite and the co-doping of DBSA and MWCNT-COOH.Finally,the effect of the content of carboxylated carbon nanotubes on the performance of MWCNT-COOH/PANI composite materials was studied,and composite electrode materials with different ratios were prepared.The results show that all the composite electrodes have a sea cucumber-like micromorphology,and the increasing content does not seriously affect their microstructure.The electrochemical results prove that when the content of MWCNT-COOH is 15wt%of the composite material,the electrochemical performance is better.