Preparation And Performance Exploration Of Flexible Electrode Materials Based On Transition Metal Compounds

Flexible solid capacitors have huge development prospects as flexible/wearable electronic devices.This dissertation focuses on the nanostructure design of transition metal compounds.Using carbon nanotube film and copper foam as conductive substrates,a series of flexible electrode materials were prepared by in-situ chemical reaction and electrodeposition methods,and their morphological structures and electrical properties were studied.Chemical properties,and use it as a positive electrode material for non-flexible solid supercapacitors.The specific research content is as follows:(1)Quaternary transition metal oxide nanosheets(Ni-Co-Mn-Mo NS)should be grown on the surface of self-supporting carbon nanotube film(CNTF)by in-situ chemistry,and carbon nanotube conductive network(CNTN)should be further deposited on the nanosheet A porous flexible electrode film(CNTF/Ni-Co-Mn-Mo NS/CNTN)with a"sandwich-like"structure was obtained.Thanks to the synergistic effect of quaternary metal oxide nanosheets and carbon nanotubes(CNT)with high electrochemical activity and reasonable layered design,the flexible electrode has excellent energy storage performance,which can reach The high specific area capacitance of 15.39 F cm^-2(2243.42 F g^-1)is superior to most reported flexible electrodes.Asymmetric flexible supercapacitors based on CNTF/Ni-Co-Mn-Mo NS/CNTN electrodes have excellent electrochemical performance,with a stable output voltage of 1.5 V and a specific capacitance of 3,378.12 m F cm^-2,corresponding to 1.17 m Wh cm^-2 high energy density.In addition,supercapacitors have excellent flexibility and stability,can work stably even under 180obending,and can maintain a high capacitance of 87.87%after 10,000 charge and discharge cycles under high current density.(2)By growing Ni Mo O₄ nanosheets with carbon nanostructures with multiple levels of nanostructures on the surface of a flexible copper foam substrate,carbon nanotubes and Cu O nanowire arrays,high-performance flexible electrodes(Ni Mo O₄ NSs@CNTs@Cu O NWAs/Cu Foam)were obtained.The electrode has the advantages of orderly spatial distribution of internal nanostructures,low inherent resistance,and short electron transmission paths.Ni Mo O₄ NSs@CNTs@Cu O NWAs/Cu Foam as a binderless supercapacitor electrode material shows good energy storage performance,and the area specific capacitance at a current density of 2 m A cm^-2 is 23.40 F cm^-2.The assembled asymmetric device has an energy density of 96.40 m Wh cm^-3 and a power density of 0.4 W cm^-3 at an operating voltage of 1.7V.In addition,at a current density of 40 m A cm^-2,the capacitance retention rate was 82.53%after 10,000 cycles.(3)We designed and prepared a flexible electric device with a foamed copper base material and a multi-level nanostructure Ni-Co phosphide@carbon nanotube@Cu O nanowire array structure(Ni Co P@CNTs@Cu O NWAs).Compared with conventional layer-by-layer composite materials,the prepared metal compound-CNTs composite electrode material have more excellent and stable electrochemical performance.The flexible electrode has excellent energy storage performance and can achieve a high specific area capacitance of 15.88 F cm^-2in 3 M KOH,which is superior to most reported flexible electrodes.The assembled asymmetric device has an area specific capacitance as high as 4,78.04 m F cm^-2 at a working voltage of 1.8 V,and its energy density and power density can be 29.79 m Wh cm^-3 and4109.96 m W cm^-3,respectively.At the same time,after 10,000 charge-discharge cycle tests,the capacitor retention rate can still maintain 89.18%.