Three Dimensional Modified MnO₂ Electrodes For Supercapacitor Application

As an important transition metal oxide,MnO₂ has been widely applied in the fields of supercapacitor,lithium-air battery,biosensors and lithium-ion cathode materials,and so on.At present,the application of MnO₂ in supercapacitor field has aroused general interest.The physicochemical property of MnO₂,such as electrical conductivity,crystal structure and nano-morphology,is a key parameter which influence and determine its supercapacitor performance.In this paper,we summarized the properties,applications and preparation methods of MnO₂ material.And,we prepared three dimensional modified MnO₂ electrodes by electrodeposition methods.The crystal structure and morphology of the materials were analyzed by using a variety of materials test methods.The electrochemistry capacitive performance of the materials was investigated by electrochemistry test methods,the application of the electrodes as asymmetric supercapacitor was systematic studied at the same time.The main details are as follows:1.A class of three dimensional composite electrodes based on PEDOT and MnO₂ was prepared by step-by-step anodic deposition method for supercapacitor application.The effect of the distribution and loading of PEDOT on the electrochemical performance of composite electrodes was investigated,respectively.2.Three dimensional MnO₂/metal?Au,Pt or Pd?/nickel foam?short as MnAuNF,MnPtNF and MnPdNF,respectively?hybrid electrodes were prepared by using double-pulse polarization and potentiostatic deposition technologies for supercapacitor application.And the impact of decorating different size Au,Pt or Pd nanoparticles onto nickel foam on the nanosheet architecture and electrochemical properties of 3D MnO₂ electrode was investigated.3.Asymmetric supercapacitors with MnO₂/Au/nickel foam?MANF?electrode as positive electrode and graphene or commercial AC as negative electrode were fabricated,respectively.The effect of different negative electrode materials?mass ratios of negative/positive electrodes and elctrolyte on the electrochemical properties of the asymmetric supercapacitor was investigated in detail.