| In recent years,with the rapid improvement of people’s quality of life,portable electronic devices have become increasingly important in daily life.And research on the stretchable energy storage system that matches it has also become a research hotspot in the scientific community.In the previous research on flexible devices,the mechanical and electrochemical properties of carbon-based materials(polymers,carbon nanotubes,graphene,etc.),which fit the requirements of flexible devices for energy storage systems,have been extensively studied.In this paper,polyurethane and single-walled carbon nanotubes are selected as film-forming substrates.Commercial lithium iron phosphate,lithium titanate,and lithium titanate nanosheets are used as active materials.Non-solvent induced phase inversion and continuous centrifugal casting are used to prepare stretchable flexible electrodes sheet.Scanning electron microscope was used to characterize the microstructure of the sample;LAND battery test system and electrochemical workstation were used to test the electrochemical performance of the sample;dynamic thermomechanical analyzer was used to test the mechanical properties of the sample;four-probe square resistance The tester tests the change in resistance after the pole piece is stretched a certain number of times.Explore the effects of different methods,different filmforming materials,and different forms of active materials on the performance of sample preparation.The analysis of the data leads to the following conclusions:(1)Polyurethane-based flexible pole pieces prepared by a non-solvent induced phase inversion method,lithium iron phosphate and conductive carbon black are uniformly dispersed in a flexible polyurethane substrate.By using four kinds of alcohols and deionized water commonly used in the laboratory as non-solvents,the surface microstructure,electrochemical properties and mechanical properties of the five flexible electrode pieces were compared.Among them,the flexible polyurethane electrode prepared with n-butanol as a non-solvent.The film has the best overall performance.(2)Single-walled carbon nanotube-based flexible pole piece prepared by continuous centrifugal casting method,lithium iron phosphate,lithium titanate and lithium titanate nanosheets are uniformly dispersed in the carbon tube film,and a little agglomeration occurs.Comparing three different active material films,it is concluded that continuous centrifugal casting is an ideal method for preparing thin films.The prepared flexible films have excellent electrochemical properties and mechanical properties,and the two-dimensional materials have better film-forming effects. |
