Study On Preparation And Electrochemical Performance Of Sisal Cellulose Nanofiber/Graphene/Polyaniline Composite Film

In recent years,Cellulose nanofiber(CNF)has become the hot topics in many field because of its large L/D,good hydrophilicity,large specific surface area,high flexibility and good biological compatibility.Meanwhile,cellulose nanofiber application in energy field has attracted researcher's attention and interest,such as used for the preparation of the flexible super capacitor electrode materials,used as the electrolyte nano storage places,dispersant of carbon-based materials and basement of conductive polymer materials,etc.As a new type of two-dimensional carbon materials,graphene(G)has many advantadges,such as large specific surface area,good structure stability,excellent electrical conductivity,and high thermal conductivity,etc.Therefore,graphene has capture much attention in the field of energy storage materials.Polyaniline(PANI)is one kind of conductive polymer materials,and it has many traits such as good environmental stability,high electrical conductivity,low cost and so on.But polyaniline has a bad cycle stability.Moreover,PANI is brittle,so adding conductive agent and adhesive is necessary when we prepare the supercapacitor electrode.However,traditional adhesive has poor mechanical performance and need to use toxic solvents during the electrode preparation,it will limits the application of polyaniline.In this paper,we use sisal fiber as raw material to prepare CNF.By using the �COOH and �OH of CNF to stably disperse graphene and PANI by the interaction of hydrogen-bond and ?-?,we hope it can provide reference for the functional application of cellulose nanofiber throuth studying the relationship between the structure and electrochemical performance of CNF/G/PANI composite.1.By using CNF as dispersant,graphene as conductive reinforcer,PANI as conductive material,we prepare different kind of CNF/G(GO,RGO,GNS)/PANI dispersion,following by filtration to obtain composite film.Study on the relationship between different kind of graphene and electrochemical performance of CNF/G/PANI composite film.Research shows that the specific capacitance of CNF/G/PANI composite film were improved by adding GO,RGO or GNS.Compare to CNF/GO/PANI and CNF/RGO/PANI,CNF/GNS/PANI composite film has highest specific capacitance which reach to 322.25 F/g,lowest charge-transfer resistance(Rct:0.77 ?)and good cycle stability(76.92% capacitance retention for cycle 1000 times under 5 A/g currentdensity).2.We prepare different GNS ratio of CNF/GNS/PANI composite film by using the mechanical blending method and the vacuum filtration.The effect of GNS content on CNF/GNS/PANI composite film`s electrochemical performance were studied.Results show that the specific capacitance of CNF/GNS/PANI composite film increased with the GNS content increased in a certain range.The composite film shows best electrochemical performance when GNS adding to 6wt%,which has highest specific capacitance reach to 342.87 F/g at 1 A/g current density,lowest Rct(1.16 ?)and good cycle stability(78.92%).3.By using CNF as nucleator and disperser,we prepare CGP composite film through in-situ polymerization and filtration,to study the effect of An`s addition on the structure and electrochemical performance of CGP composite film.Research shows that the specific capacitance of CNF/GNS/PANI composite film increased first and then go down with the GNS content increased.CGP1:15 composite film has best electrochemical performance,the specific capacitance reach to 342.87 F/g at 1 A/g current density,and the specific capacitance only decline 22% when the current density come to 10 A/g.In addition,it has lowest Rct which is only 1.65 ? and good capacitance retention which reach to 79.33% for cycle 1000 times under 5 A/g current density.