Preparation And Electrochemical Properties Of Metal Oxide/Polyaniline Nanomaterial

The metal oxide and PANI are two kinds of electrode materials of supercapacitor with pseudo-capacitance characteristics,and have the characteristics of low cost,environmental friendliness etc.The metal oxides exhibit good chemical stability,and the polymers have good conductivity after being doped with protonic acid at the same time.If the metal oxide is combined with PANI,they may produce synergetic effect,so that the composites can simultaneously obtain their advantages and improve the electrochemical performance.In this paper,Mn²⁺、Zn²⁺、Cu²⁺、Co²⁺doped PANI were prepared firstly.And the effects of these metal ions on the formation and electrochemical properties of PANI were analyzed.Then Mn₂O₃/PANI and Co₃O₄/PANI were synthesized respectively,and their morphology,structure and electrochemical performance was analyzed.There are the main conclusions as follows:（1）Mn²⁺、Zn²⁺、Cu²⁺、Co²⁺and so on,have been found to have an advantageous effect on the redox reaction of the PANI.The electrochemical performance of the doped sample is improved compared with the pure PANI.Especially,the specific capacitance of PZn is the biggest with a value of 685 F/g at 1 A/g,which is 2.23 times as much as that of pure PANI.At the same time,the slope of EIS curve of PZn in low frequency region is the largest,showing a good diffusion and high conductivity,which is beneficial to the electron transport in the reaction.（2）In order to further explore one metal element effecting on the electrochemical performance of PANI,Mn ions and Mn₂O₃ were respectively used to doping with PANI.The results show that not only Mn²⁺can improve the specific capacitance of PANI but also the Mn₂O₃ can improve the doped PANI capacitance performance.Herein Mn₂O₃ was added by in-situ polymerization.The corresponding capacitance is719 F/g at a current density of 1 A/g and the capacitance retention is 92.3%after 2000charge–discharge cycles at 10 A/g.Obviously,the addition of Mn₂O₃ can significantly improve the electrochemical performance of PANI.（3）In order to increase the content of metal oxide in the composites,it is prepared Co₃O₄/PANI composites with different molar ratio of 1:3,1:5,1:8 and 1:10.Herein Co₃O₄ nanofibers are prepared by electrospinning.And Co₃O₄/PANI composites are synthesized by in-situ-polymerization method.The electrochemical measurement results show that Co₃O₄/PANI（1:5）exhibits a very high specific capacitance of 1124 F/g at 1 A/g,and good conductivity and ion diffusion performance.Especially,it has excellent cycling stability with a capacitance retention of 73.97%after 5000 cycles.Co₃O₄ nanofibers/PANI system takes on the best electrochemical performance.