Preparation And Properties Of Supercapacitor Electrodes With Titanium Foam As Current Collector

Supercapacitor is a promising energy storage device with advantages of fast charge and discharge rate,good cycle stability and large voltage working range.However,supercapacitor also has some disadvantages such as low energy density.The electrodes of supercapacitor are mainly composed of current collectors and active materials,which are the key factors determining the performance of supercapacitors.Therefore,the preparation of high performance electrode is the focus of current research on supercapacitor.Titanium foam is a porous light metal material with the advantages of low density,large specific surface area,high strength and good corrosion resistance.In this paper,Mn O₂-Ti O₂ nanotube array/titanium foamcomposite electrode and Mn O₂-PANI/titanium foam composite electrode were successfully prepared by using titanium foam as current collector.The morphology,structure and composition of the composite electrodes were analyzed and characterized.The properties of the composite electrodes were tested and the effects of preparation conditions on the performance of the composite electrode were investigated.1.Firstly,Ti O₂ nanotube arrays were prepared on the surface of titanium foam by anodic oxidation method,then Mn O₂ was deposited into Ti O₂ nanotube array by one-step redox precipitation method to prepare Mn O₂-Ti O₂ nanotube array/titanium foamcomposite electrode.The effects of water content,anodic oxidation time,concentration of manganese sulfate solution and porosity of titanium foam on the performance of composite electrode were studied.The optimal preparation conditions of Mn O₂-Ti O₂ nanotube array/titanium foam composite electrode were obtained through a series of experiments.The charge,discharge and cycle performance of Mn O₂-Ti O₂ nanotube array/ttanium foam composite electrode under optimal preparation conditions were investigated.When the current density was 0.1 m A/cm²,the surface capacitance was 436.2 m F/cm²,and the capacitance retention was 85.7%after 3000 cycles.In addition,Li Cl,Na Cl,KCl,NH₄Cl and Na Br,Na I,CH₃COONa were used as test electrolytes respectively.The effects of cations and anions on the performance of the composite electrode were investigated.The results show that the smaller the ionic radius of cations and anions,the larger the capacitance of the composite electrodes.2.Two-step cyclic voltammetry method was used to deposit PANI and Mn O₂ onto the surface of titanium foam to prepare Mn O₂-PANI/foam-titanium composite electrode.The effects of the aniline concentration,the time of depositing polyaniline,the scan rates of depositing polyaniline,the concentration of manganese acetate,the time of depositing manganese dioxide,the scan rate of depositing manganese dioxide,the solvent used to dissolve aniline and manganese acetate on the performance of composite electrodes were studied,and the related reasons were discussed.The optimal preparation conditions of Mn O₂-PANI/foam titanium composite electrode were obtained through a series of experiments.The charge-discharge and cycle performance of the composite electrodes at voltage window of 0-0.8 V and 0-1.5 V under optimal preparation conditions were investigated.When the current density was 0.2 m A/cm²,the areal capacitances were 94.6m F/cm² and 97.4 m F/cm²,respectively,and the capacitance retention rate can be maintained above 90%after 5000 cycles.