Preparation And Properties Of Functionalized Flexible Supercapacitors

Among the various new energy storage systems,supercapacitors are the most promising devices due to their excellent specific capacitance,high power density,and outstanding cycling stability.Meantime,with the development of portable and wearable electronic devices,the functional supercapacitors,such as flexible,stretchable,and waterproof supercapacitors,have attracted significant attention.Based on these principles,high electrical performance and multi-function supercapacitors are very valuable.So the functional and high-performance graphene/polyaniline supercapacitors are studied in this thesis fromdifferent aspects.In terms of structure,the supercapacitors with graphene/polyaniline electrodes of porous three-dimensional structure(3D-RGO/PANI)are designed.Supercapacitors based on 3D-RGO/PANI electrode material have specific capacitance of>1000mF/cm² at scanning speed of 5 mV/s.The specific capacitance of the supercapacitors is 401.3 mF/cm² at scanning speed of 50 mV/s,which increased by nearly 20%compared with that of supercapacitors with common electrode.In terms of components,ternary composites electrodes with different composition ratios of the graphene(RGO),polyaniline(PANI)and molybdenumdisulfide(Mo S₂)are prepared.The RGO/PANI@Mo S₂ ternary composite filmshows excellent electrochemical performances,and the supercapacitors with these filmelectrodes have the capacitance of 643.3 mF/cm² at 10 mV/s.The volumetric capacitance of supercapacitors is>2000 F/cm³,since the thickness of films is only 3?m.The post-capacitance retention is over 80%after 1000 charge/discharge cycles.In this work,we developed a surprising approach to assemble the all-in-one flexible supercapacitor which integrates current collectors,electrodes,and electrolyte(use as separator at same time)and includes no any other additions.The all-in-one supercapacitors have the specific capacitance of 85.3 mF/cm² at a scanning speed of 5mV/s.Furthermore,the all-in-one supercapacitors have many excellent properties,such as high tensile properties.The tensile strength of the electrode material is close to 6 MPa,and the elongation at break is higher than 650%.