Preparation Of Mattress-like Carbon Paper Based On Graphene And Its Application In Supercapacitor

Supercapacitors are high-power energy storage devices that store charge on electrode through electrical double layer and redox reactions.As a new type of energy storage device,supercapacitor possesses wide application prospects due to its advantages of fast charge and discharge,long cycle life,environmental friendliness.The preparation of high-performance electrode materials has been the research focus of supercapacitors.Researchers have developed effective and flexible electrode materials to effectively improve their performance.Under the premise of improving the energy and power density of the supercapacitor,it is urgent to seek for a simple and low-cost method to fabricate free-standing active electrode with high utilization rate and good economic benefits.Graphene's unique structure offers excellent mechanical properties,electrical properties and high specific surface area,making it play a major role in the flexible electronic devices and energy field.In this thesis,the lower graphene paper and upper graphene film of electrode are prepared by thermal deposition method,and the active interlayer with good conductive characteristic is prepared by simple flame method.In the whole preparation process of free-standing electrode,the conductive agent and adhesive are avoid.Finally,the microstructure and electrochemical performance of the mattress-like free-standing electrode are analyzed and discussed.The specific research contents of this thesis are as follows:(1)Free-standing electrodes without conductive agent and adhesive are peeled off by the manually peeling method,and their electrochemical performance is analyzed.The special helical nanocarbon of interlayer in the electrode has high conductivity,electrochemical activity and mechanical robustness compared with disordered nanocarbides due to its high crystallinity,large surface area and superior elasticity.Therefore,the area specific capacitance of this electrode used for supercapacitor can reach 1.07 F cm-2,and the capacitive retention after 1000 cycles is 93.02%.The symmetrical supercapacitor based on this electrode,the capacitive retention at 120°bending is 81.22%.(2)The layered stack of composite inlaided helical nanocarbon interlayer by flame synthesis,and naturally dried mattress-like carbon paper will be self-peeling form free-standing.In compared to the manual peeling method,the self-peeling ensure the integrity of electrode itself to reduce damage and destruction.The addition of Na2MoO4 reagent in precursor solution do not affect the formation of helical nanocarbon which embedded in the layered structure well.We use self-peeling free-standing as supercapacitor electrode,which shows good electrochemical performance and mechanical robustness during electrochemical tests.The area specific capacitance of this electrode is as high as 1.45 F cm-2,and the capacitive retention after 1000 cycles is 98.33%,indicating excellent cycle stability.The symmetrical supercapacitors based on the electrode maintain a capacitive retention of 86.87%at a bending angle of 120°,indicating that the electrode has high mechanical stability.