Study On Pseudocapacitive Material Used As Supercapacitor Electrode Material

A notable improvement in performance has been achieved through recentadvances in understanding charge storage mechanisms and the development ofadvanced nanostructured materials. Using the the subnanometer pore structure of theelectrochemical double layer capacitor has a high specific capacitance. Combinationof pseudo-capacitive nanomaterials, including oxides, nitrides and polymers, withthe latest generation of nanostructured lithium electrodes has brought the energydensity of electrochemical capacitors closer to that of batteries.Researches on the synthesis, modification and composite materials ofsupercapacitor electrode have been done on this article. The morphology of theelectrode materials are observed by SEM, the structure characterization are analyzedby XRD and FTIR, and cyclic voltammetry, Galvanostatic charge-discharge, ACimpedance spectroscopy measurements and cycle life test were carried out to test theperformance of supercapacitors. The main content is as follow:The MnO₂/CNTs composite electrode material were Synthesised byhydrothermal method.It was found,by optimizing the conditions,that: When thehydrothermal time was about6h,and the hydrothermal temperature of120℃,thesupercapacitor showed the best electrochemical performance. The specificcapacitance of the supercapacitor achieved the highest value of174.24F g^-1and thecharge-discharge efficiency of94.92%.The NiO/CNTs composite electrode materials were prepared by hydrothermalmethod, and to optimize the preparation conditions: When the amount ratio ofsubstance of nickel oxide with carbon nanotubes （Ni2+: C） was1:1, the specificcapacitance of the NiO/CNTs electrode supercapacitor reached232F g^-1, increasingby4.15times compared with the nickel oxide supercapacitors system undopedcarbon nanotubes. The energy density of the composite electrode materialssupercapacitor has also been significantly improved to4.03Wh kg^-1. In addition, thesupercapacitor also exhibits excellent cycle-life stability.Doped PEDOT electrode material was prepared by the method ofelectrochemical polymerization at room temperature by cyclic voltammetry and wastested in sodium sulfate solution. The research results show that with the reductionin the rate of electrodeposition, the electrochemical performance of supercapacitorhas greatly improved. And the best performance rate of the polymerization was100 mV s^-1. The specific capacitance of supercapacitor achieved high value of159.8Fg^-1,increased by5%in capacitance compared to the deposition rate of200mV s^-1of thePEDOT electrode material. Energy density of the supercapacitor has beensignificantly improved, which was about11.09Wh kg^-1. In addition, thesupercapacitor of a conductive polymer electrode material also exhibited excellentcycle performance, and after1000cycles, and still maintain a high specificcapacitance.