Research On Preparation And Capacitance Performance Of Elastic Electrode Based On Sponge Composite Material

With the rapid development of wearable electronic devices,the demand for flexible energy storage devices is also increasing.Among them,flexible supercapacitors with the advantages of high power density,long service life,and fast charging-discharging have become a research hotspot for researchers,but there are few reports on the work of compressible elastic devices.The electrode of a supercapacitor is an important factor that determines its electrochemical performance.At the same time,as an electrode of elastic supercapacitor,the mechanical properties are also an important indicator.Cheap and easily available kitchen sponges have good mechanical elasticity and natural three-dimensional skeleton,which can be used as a base material to compound with other active materials to prepare flexible supercapacitor electrodes.In this paper,a series of composite tests were carried out with sponge as the substrate,which proved that this three-dimensional substrate material has a very positive significance for the preparation of elastic electrodes.The main content and results are as follows:(1)The feasibility of using sponge to prepare elastic supercapacitor electrodes is proved.A elastic MS/r GO(melamine sponge/graphene)composite electrode was prepared by a simple method.Graphene can grow uniformly in the three-dimensional frame of the sponge,which greatly enriches the specific surface area of the composite material.The assembled supercapacitor can reach a specific capacitance of 90 F g^-1at a current density of 1 A g^-1,and has excellent cycling performance.At the same time,a compression test was performed on the assembled device.Due to the elastic properties of the sponge,the device can quickly recover after being compressed,proving its operability as an elastic supercapacitor electrode.(2)Carbon foam(CF)with three-dimensional framework was obtained by carbonizing MS,and Mn O₂nanosheets were uniformly grown on the CF framework by electrodeposition to provide high pseudocapacitance performance.A three-electrode test was performed on the composite material.Due to the existence of the three-dimensional conductive framework,the Mn O₂nanosheets give full play to the pseudocapacitance performance in this system,and the specific mass capacitance can reach 365 F g^-1.At the same time,the carbonized CF still retains the elasticity of the original sponge,and the supercapacitors assembled with composite materials show good elastic deformation characteristics.(3)A CF/r GO/PANI(carbon foam/graphene/polyaniline)supercapacitor elastic electrode with high electrochemical performance and excellent elasticity was prepared.CF has a three-dimensional conductive frame to ensure the rapid conduction of electrons and ions during charging-discharging.The reduced graphene oxide nanosheets provide a growth area for PANI nanorods,and PANI nanorods provide excellent pseudocapacitance performance.The symmetrical supercapacitor assembled with the ternary composite electrode has a specific mass capacitance of 533 F g^-1.After the compression strain test,the electrochemical performance of the assembled supercapacitor remains stable,and the shape of the device can be completely restored.Whether it is a three-electrode test or a two-electrode test after assembling a symmetrical supercapacitor,it can be proved that sponge is the base material,and its three-dimensional network structure is combined with graphene,metal oxide and conductive polymer to effectively improve the electrical conductivity.This strategy also ensures the excellent elastic properties of the composite electrode,which can be used to prepare elastic supercapacitors.