Preparation And Performances On Three Dimensional Flexible Supercapacitor And Electrode Materials

Wearable flexible supercapacitor is a very popular research of intelligent material in the future.Because of its high power density,long cycling life,environment-friendly,strong adaptability and other advantages,more and more attention have been paid by the researchers in academics and industry.The fixed shape of the traditional supercapacitor greatly limits the development and application of the energy storage device.Therefore,on the basis of the traditional supercapacitor,giving new characteristics of folding,flexibility and portability will increase the prospect its application.At present,how to develop supercapacitors with high flexibility and excellent electrochemical performance has become one of the urgent problems in the field of energy storage research.First of all,the selection of appropriate substrate materials is the prerequisite for the preparation of flexible supercapacitors.Generally,there are three kinds of flexible substrate materials: metal based substrate materials,carbon based substrate materials and cellulose paper based substrate materials.Cellulosic paper-based materials have the characteristics of low cost,recyclable usage,high flexibility and three-dimensional pore structure.Therefore,it is becoming a hot research of the flexible electronics.In order to improve the electrochemical storage performances of the flexible supercapacitors,the current common method is to study and prepare hybrid supercapacitors with different capacitance effects.Binary,ternary or multiple composite electrode materials,which combine the double-layer electrochemical active materials and Faraday electrochemical active materials together,can play a synergistic role in different active materials and take the respective advantages of each material.In this paper,titanium metal-base,cellulose sheet mask paper-based and filter paper based flexible electrode materials were prepared by chemical vapor deposition,electrochemical deposition,vacuum filtration and chemical oxidation reduction methods.Meanwhile,a superthin flexible supercapacitor with two electrodes on a filter paper was successfully prepared and assembled.The three-dimensional and vertical growth of carbon nanotubes/polyaniline composite materials were prepared by chemical vapor deposition and electrochemical deposition methods.Firstly,the titanium sheet was put into the furnace to prepare polyaniline/carbon nanotubes/titanium by chemical vapor deposition.When the temperature was stable at 850 ℃,10 m L xylene solution containing 0.5 g ferrocene was injected into the furnace as carbon source.After reaction for 50 min,the vertically grown carbon nanotube/titanium composite was cooled to the room temperature.Secondly,by using the electrochemical deposition method and reasonable control of electrodeposition time,the three-dimensional structure of polyaniline/carbon nanotubes/titanium flexible composite electrode material was successfully prepared.The results demonstrated that the as-prepared flexible composite electrode material not only showed great flexibility,but also showed excellent electrochemical performances.The three-dimensional structure of polypyrrole/ferroferric oxide/carbon nanotube /sheet mask paper composite electrode material was prepared by the combination of vacuum filtration and chemical oxidation methods.Firstly,the ferroferric oxide/carbon nanotube/cellulose mask paper bybrids were prepared via the vacuum filtration method.Then,polypyrrole was synthesized by chemical oxidation on the above composite material.Then,the three-dimensional porous polypyrrole/ferroferric oxide/carbon nanotube/mask paper composite electrode materials were successfully prepared.The results showed that the flexible electrode material not only reduced the production cost,but also demonstrated the excellent electrochemical performances.Silver doped reduced graphene oxide composite electrode material was prepared by using the safe and pollution-free reducing reagent L-ascorbic acid on the flexible substrate of filter paper.Firstly,the filter paper was impregnated with silver nitrate and graphite oxide.Secondly,the reagent of L-ascorbic acid was added to reduce silver nitrate and graphite oxide to silver and graphene in one step.Then,a conductive polymer of polyaniline was grown on the surface of the flexible composite mentioned above by electrochemical deposition.Therefore,the flexible electrode material of polyaniline/silver/reduced graphene oxide/filter paper was successfully prepared.The results showed that the as-prepared electrode material not only displayed excellent structural characteristics,but also had very good electrochemical performances.In this paper,a layer of carbon nanotube active material was uniformly deposited on the two surfaces of a piece of filter paper via the simple method of vacuum filtration method.Then,the active materials of ferroferric oxide and zinc oxide were deposited on each side of the as-prepared composite,which was containing with carbon nanotubes on the two surfaces.Therefore,a separator free supercapacitor composite material with two electrodes on a piece of filter paper was successfully prepared.After assembled with packaging materials and electrolyte,the flexible asymmetric supercapacitor was tested by means of morphology,microstructure and electrochemical analysis,respectively.The results showed that the structure of the flexible asymmetric super capacitor was of great novelty and originality,the thickness was only 150 μm,which was much thinner than most of the supercapacitors.On the other hand,due to the asymmetric structure of the assembled supercapacitor,the electrochemical performance was also considerable.