Preparation And Properties Of Compressible Electrodes Based On Highly Elastic Three-dimensional Graphene

The development of portable and wearable electronic devices has greatly enriched our daily life,but the energy storage devices that can be matched with them have been slow to develop and become an important constraint.New portable and wearable electronic devices should meet the requirements for use in special environments,all of which require corresponding energy storage devices.Deformation-resistant energy storage equipment mainly needs to withstand three deformations?bending resistance,tensile strength and compression resistance?,which require our energy storage equipment to withstand higher strength vol?me deformation.At present,the main research focus of deformation-resistant energy storage equipment is flexibility,and there are few studies on compressibility.Supercapacitor?SC?is an energy storage device with high power density,fast charging speed and long cycle life.It will have broad application prospects in the power supply of portable and wearable electronic devices.In recent years,three-dimensional graphene aerogels with ordered porous structures have been reported,with good mechanical properties and electrical properties.Based on the three-dimensional graphene materials,this paper focuses on the preparation of highly elastic three-dimensional graphene aerogel materials by ice stencil method and hydrothermal synthesis method,and the preparation of three-dimensional graphene and high-capacity materials by electrochemical deposition.Binary and ternary composite materials to obtain a three-dimensional graphene composite material with high elasticity and high specific capacitance.The above materials serve as compressible electrode materials,providing new ideas for the study of compression-resistant supercapacitors.?1?Firstly,a high elastic three-dimensional graphene aerogel was prepared by ice stencil method,and the influence of some experimental parameters on its mechanical properties was studied.The three-dimensional graphene aerogel has a directional ordered porous structure with a pore size of about 100–500?m.Later,the polyaniline is supported on the surface of the three-dimensional graphene by electrochemical deposition,which can significantly improve the specific capacitance characteristics of the material.In the three-dimensional graphene/polyaniline composite,the three-dimensional graphene aerogel provides a continuous conductive network and a tough skeleton for polyaniline.The deposited polyaniline not only improves the specific capacitance,but also maintains a high compression resistance.Sex.Tests show that the composite can withstand 90%of the compressive strain,and the structural integrity can be maintained after1000 times of compression recovery.The specific capacitance can reach 424F/g in the three-electrode system environment.The all-solid supercapacitor test based on the electrode material shows that the specific capacitance can be maintained at 96%when the vol?me is compressed by 90%,and the loss is small,and the vol?me specific capacitance in the compressed state can reach 85.5 Fcm^-3,which is superior to other resistance.Compress the electrode material.?2?In order to further increase the material vol?me ratio capacitance,it is one direction to improve the specific capacitance characteristic by ternary recombination while maintaining the elasticity without loss.In this paper,a ternary composite was prepared based on the three-dimensional graphene method of ice template method,and polypyrrole and manganese dioxide were successively supported on the surface of the three-dimensional graphene aerogel by electrochemical method.The porous structure of three-dimensional graphene provides a load skeleton for other materials;the intermediate polypyrrole layer not only reduces the interfacial resistance between the graphene layer and the manganese dioxide layer,but also strengthens the mechanical properties of the graphene wall layer,resulting in composite performance.A greater compressive strain capacity?95%?;manganese dioxide plays a key role in capacitor boosting.Tests show that the composite has a specific capacitance of 366F/g,and can maintain a specific capacitance of 95.3%when the vol?me is compressed by 95%.The loss is small,and the vol?metric specific capacitance in the compressed state can reach 138 Fcm^-3.?3?Due to the physical properties of the three-dimensional graphene material,it has been impossible to further improve the specific capacitance characteristics by loading a high-capacitance material.Therefore,further improving the mechanical properties of the three-dimensional graphene material in order to increase the elasticity is another direction for increasing the vol?me ratio of the electrode material.The hydrothermal synthesis method is an effective method for preparing elastic three-dimensional graphene aerogel.During the hydrothermal reaction,the GO sheet is cross-linked,and a three-dimensional structure is formed under the van der Waals force,followed by freezing to further strengthen the graphene pores.Wall mechanical properties.This highly elastic three-dimensional graphene aerogel with excellent mechanical properties can reduce the effect of solvent evaporation capillary pressure.The test found that the material can withstand 95%of the compressive strain,and then load the high-capacitance material to increase its vol?metric capacitance.