Fabrication And Application Of Metal Sulfide/Oxide Nanostructures In Flexible Pressure Sensors And Supercapacitors

With the advent of the 5G era,people's thirst for smart life is becoming stronger and stronger.As an important symbol and one of the core components of smart life,flexible devices,especially flexible sensors(FPS)and compressible supercapacitors(CSC),have provided new fields for biomedical technology,energy,and electronic devices.FPS has become a research hotspot because of its advantages such as flexibility,convenient movement and more effective signal acquisition.CSC can make up for the shortcomings of the rigidity of the power supply of FPS because of its long cycle life and good bendability.And people are more and more hoping to combine the two devices to meet multiple needs,but there are still many problems in the research of multifunctional devices.In this regard,we built a series of metal sulfide/oxide nanostructure arrays,using different growth pathways,for preparation of high-performance FPS and CSC.The research work and innovations of the dissertation are as follows:1.Nanostructured metal sulfide/oxide eletrodes with different dimensions were grown on the carbon cloth surface by using a facile hydrothermal method,namely 1D Co9S8 nanoneedles,2D NiCo2O4 nanosheets,and 3D NiCo2O4@Co9s8 nanotrees.The flexible capacitive pressure sensors(CFPS)were fabricated by wrapping these three nanostructures with polydimethylsiloxane(PDMS)films.Among them,the sensors based on nanotrees have the best performance,with a sensitivity of 0.08 kPa-1.Under high pressure,it can circulate steadily for 1000 times.2.Interdigial electrodes were used to assemble with the 3D NiCo2O4@Co9S8 nanotrees to obtain resistive pressure sensors(RFPS),which were encapsulated with polyethylene film(PE)and showed higher sensitivity compared with the above-mentioned CFPS.Its sensitivity was increased to 0.6 kPa-1,the number of cycles reached 2000,and RFPS can detect small movements such as human breathing,heartbeat,and swallowing.3.We had utilized the rich network structures of carbonized melamine sponge(CMF)and adopted hydrothermal methods to grow multiple metal sulfide/oxide nanostructures on such skeleton.CMF@nanostructured materials have both electrochemical performance and excellent pressure sensing ability.After the electrodeposition of the Ni layer,the specific capacitance was increased by 2 times.In terms of pressure sensing,the maximum dynamic pressure was 5 kPa and the number of cycles was 2000,which provides the basis for multifunctional devices.