Study On Preparation And Properties Of Manganese Oxide/Graphene Composites

Supercapacitors have been studied by many researchers as an excellent new energy storage device for many years because of their high power density,excellent safety performance,long cycle life and strong charging and discharging ability.As the key to the storage performance of supercapacitors,electrode materials have also attracted much attention.Manganese dioxide inherits its excellent properties as a transition metal oxide.With the advantages of multi-morphology,low cost,high theoretical specific capacitance and excellent electrochemical performance,it has become an excellent choice for electrode materials of supercapacitors.However,nanostructured manganese dioxide is easy to agglomerate when it is stored alone,and its conductivity is poor.It is limited in capacitor applications.Therefore,it can solve the problem of poor conductivity by compounding nanostructured manganese dioxide with carbon-based materials with large specific surface area.Therefore,this paper is devoted to the study of supercapacitor electrode materials with excellent performance,using manganese oxides and hydroxides as matrix materials,and then compounded with polyaniline?PANI?,reduced graphene oxide?rGO?,carbon nanotubes?CNTs?,respectively,to prepare composite materials and conduct in-depth research on their many properties.The main contents and conclusions are as follows:?1?rGO/MnOOH@PANI composites:graphene oxide was prepared by improved Hummers method,and then rGO/MnOOH two-dimensional composites were prepared by hydrothermal method.Then aniline was added to the composites,and polyaniline was synthesized by in-situ polymerization of aniline under the action of oxidant,thus rGO/MnOOH@PANI composites were prepared.The morphology,structure and electrochemical properties of the composites were studied.It was found that the composites had excellent electrochemical properties.?2?Graphene/Ultra-long MnO₂nanowire composite membrane:According to the hydrothermal preparation process of graphene oxide,a certain concentration of GO aqueous solution was prepared,and then ultra-long MnO₂nanowires were prepared by hydrothermal method.After mechanical stirring and ultrasonic mixing filtration,graphene/Ultra-long MnO₂nanowire composite membrane was obtained.The morphology,structure and electrochemical properties were studied.It is proved that the composite film has good electrical conductivity,mechanical and electrochemical properties.?3?Ultra-long MnO₂nanowires/multi-walled carbon nanotubes composite film:According to the preparation process of manganese dioxide nanowires,a certain concentration of suspension was prepared,a certain amount of carbon nanotubes was weighed and acidified,and then a super-long MnO₂nanowires/multi-walled carbon nanotubes composite film was prepared by mixing mechanical stirring and ultrasonication.The morphology,structure and electrochemical properties of the film were studied.It is found that the composite film has good conductivity and electrochemical properties.