Preparation Of Graphene-Molybdenum Matrix Composites And Its Application Of Supercapacitor

In order to meet the urgent energy demand,the research of developing environmental-friendly and pollution-free energy storage equipment and advanced energy conversion devices to replace traditional resources has attracted the research workers in recent years.Supercapacitors?SCs?,as a new type of energy storage device,have received international attention owing to their outstanding characteristics such as high capacitance,fast charging/discharging,long life and safety.The exploration of electrode materials has become an important part of the research work so as to improve the electrochemical performance of SCs.Graphene is an ideal electrode material because of its excellent properties.At present,due to a large number of constraints on the large-scale commercial application of graphene,most of the graphene used today is obtained by reduction of graphene oxide.To overcome the Van der Waals force between the graphene sheets and improve the agglomeration phenomenon,the metal oxide?hydroxide?,the conductive polymer and the graphene material are composited.And the prepared electrode material exhibited superior performance.In this paper,electrode materials with high specific capacitance and good cycle stability were prepared by loading other materials on the surface of graphene.The research contents and results are as follows:?1?Firstly,NiCl₂·6H₂O is used as the nickel source,Na₂MoO₄·2H₂O is used as the molybdenum source,urea is used as the precipitant,and deionized water is used as the solvent to prepare the flower-like NiMoO₄ with two-step hydrothermal method.Graphene oxide?GO?as a substrate,GO and NiMoO₄ were added to the PTFE inner liner in a certain proportion,and then the three-dimensional NiMoO₄/rGO composites were prepared by self-assembly.The composites were used for the SCs electrode material and exhibited excellent electrochemical performance.The specific capacitance is as high as 1775 F g^-1 at a current density of 0.5 A g^-1.The cycling stability was tested at a current density of 1 A g^-1,and the specific capacitance retention was 93.9%after 5000 times.Assembled into an asymmetric capacitor device,the energy density was 39.6 W h kg^-1 at a power density of 372 W kg^-1.?2?In this paper,we demonstrated an efficient and universal strategy to fabricate Fe-Anderson-type polyoxometalate/polyaniline/graphene hybrid aerogels via a facile hydrothermal technology involving?NH₄?₃[FeMo₆O₂₄H₆]·7H₂O possessing the well-known Anderson structure.With different adding amount of PANI/GO,the Fe-Anderson-type polyoxometalate/polyaniline/graphene materials showed different loading results,further impacting supercapacitor performances by regulating ion and electron transport circumstances.The materials have been verified that possess high specific capacitance(1366 F g^-1 at a current density of 1 A g^-1),good cycling stability?97.6%capacitance retention after 5000cycles?.In addition,there is the highest energy density of 24.65 W h kg^-1 at a low power density of 326.25 W kg^-11 and good cycling stability?94.82%capacitance retention after 5000cycles?for asymmetric supercapacitor.