Research On Synthesis And Energy Storage Device Performance Based On 2D/3D Nanomaterials

Facing the rapid deletion of fossil fuels and the terribly environmental pollution caused by the fossil fuel combustion,people have to seek a clean and renewable energy to address these serious problems.Currently,these proficiently used of renewable sources,such as solar energy,wind energy,geothermal energy etc,often converted into the electrical energy in a large scale.However,the electrical power produced by renewable energy significantly relies on natural conditions and is not even continuous.Due to these adverse factors,it is very difficult for human to efficiently make use of new energy.At present,the most effective approach is to storage electrical power converted from renewable energy for human flexibility.These energy storage devices,such as lithium-ion battery,lead-acid battery,supercapacitor and fuel cell,often were used in human market.Among various energy storage devices,the lithium-ion battery and lead-acid battery not only suffer from a somewhat low energy density and power density,and the abandoned batteries create a tremendous pressure on environment.While fuel cell with ultrahigh energy density and supercapacitor with ultrahigh power density represent the most promising energy storage device in a large scale.Currently,in addition to the process of device fabrication,the developement of both storage device are highly depent on the performance of electrode material.Fuel cell is a device that burns hydrogen.So hydrogen produced by water splitting has a great application prospect in fuel cell.Water splitting contains two half reactions.As for the anodic reaction,which needs four electron power,has been regarded as a major bottleneck in overall water splitting process.So a higher overpotential is required to maintain hydrogen generation.Currently,the most active catalyst is IrO2 and RuO2,but their applications were limited by high cost and scarcity in nature.Besides,in order to achieve the application in industry in a larger scale,the cost of prepared process is also considered.Supercapacitor,a new energy storage device between the convention capacitor and secondary battery,has the advantages of ultrahigh power density and long cyclic life.Meanwhile,various flexible devices have been developed implies that flexible supercapacitor as an energy storage device has a broad market prospect,which is hindered by the lower energy density.Based on the unfavorable factor,graphene,a novel sheet material consist of carbon atoms,possesses unique mechanical,excellent conductivity,as well as ultrahigh specific surface area,which has a great application in supercapacitor.However,some unfavorable factors,such as large-scale production graphene,the aggregated graphene during the process of energy storage,are urgently needed to be addressed.To solve the above problems,the main contents were listed as follow:(1)The CoFe layered double hydroxide(CoFe LDH)with good crystal and regular morphology was prepared by a simple co-precipitation method.We investigated that the Co/Fe ratios in precursor solution influence the LDH structure and OER activity.In order to further improve the activity of CoFe LDH,a 3D CoFe LDH/NF was prepared by a self-assemble method,exhibiting excellent durability and activity toward OER.(2)A porous nitrogen-doped graphene based composite(PNGC)was prepared with in-situ polymerization,pre-carbonization,KOH activation in turn.Compared with the pure porous graphene composite(PRGO)and the porous N-doped carbon(PNC)derived from PANI,the PNGC exhibited better performance on supercapacitor.Besides,we also investigated that the different concentrations of aniline in the precursor solution play a role on the PNGC electrochemical performance.As a consequence,the PNGC-8 prepared with the 0.08M aniline exhibited the best electrochemical performance in supercapacitor.(3)An all-solid state flexible of supercapacitor package was designed and fabricated.The flexible supercapacitor based on PNGC-8 electrode material using PVDF-HEP/EMIMBF4 gel ionic not only had a high specific capacitor,after bending even at 180° and bending 1000 times repeatedly,also exhibited excellent performance on flexible performance.