Study On Preparation And Propertities Of Carbonized Bacterial Cellulose/graphene Composites For Supercapacitor

Supercapacitor possesses numerous advantages.For instance,rapid charge and discharge speed,high power density,long cycle life and environmental friendliness.So it has been attracted much more attention and showed great application potential in information,aviation,spaceflight and electric vehicle fields.It is known to all,electrode is the core component of supercapacitor,and so the applied materials of electrode directly affect the performance of the capacitor.Carbon material is the earliest electrode material used in supercapacitor because of its excellent conductivity,large specific surface area,high stability and low cost.What's more,Carbon material is also one of the most successful electrode materials in industrialization.The m-BC/GEusedtBCasbasementmembranewasfabricatedby membrane-liquid-interface method in this paper,and then prepared by carbonization process.Subsequently,the electrochemical properties was studied,which acted as the electrode materials for supercapacitor.In this paper,m-BC/GE was analyzed by scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,Raman,X-ray diffraction?XRD?and in-situ biaxial tensile testing to study the morphologys,microstructures and mechanical properties.The results showed that m-BC/GE composites with GE nano-sheets uniform dispersion and controllable thickness have been sucessfully synthesized by membrane-liquid-interface method.The m-BC/GE duplicated the three-dimensional network structure of BC;on the other hand,GE nano-sheets were uniformly dispersed in the three-dimensional structure of BC.More importantly,the uniform dispersion of GE nan-osheets and the synergetic effect with BC enhanced the mechanical properties of m-BC/GE.With t the content of GE nano-sheets increasing,the tensile strength and Young's modulus of m-BC/GE gradually improved.The tensile strength of m-BC/GE with 0.19?t%GE contents reached 1.7 MPa,70%higher than that of mBC,and Young's modulus reached 33.4 MPa,230.7%higher than that of mBC.To evaluate their microstructures,crystal structures and electrochemical properties,C-mBC and C-m-BC/GE prepared by carbonization were determined by SEM,TEM,XRD,XPS,compression test and electrochemical test.The results showed that C-m-BC/GE with ultra-light characteristics had subtler three-dimensional network structure and lighter weight compared to mBC,and also had excellent flexibility and compression recovery property.The uniform dispersion of GE nano-sheets in BC contributed to improving the specific surface area.The electrochemical test results showed that the C-m-BC/GE₃ exhibited the best electrochemical performance.Its specific capacity could achiev to 238.1 F g^-1 at the scanning rate of 5 mV s^-1 and 224.5 F g^-1 at the current density of 1 A g^-1,respectively.And the power density and the energy density could reach to 478.8 W kg^-1 and 19.9 W h kg^-1 at the current density of 1 A g^-1,respectively.After 5000 cycles,the specific capacity of C-m-BC/GE₃ still remained 95.6%at the scanning rate of 50 mV s^-1,which illustrated that C-m-BC/GE₃ had desired cycling stability.