Studies On The Composite Materials Based On The Molecular Sponge PMo₁₂ With Graphene For Energy Storage

A multi-electron redox phosphomolybdic acid(PMo12)shows great potential for energy storage such as battery,supercapacitor,and electrocatalyst.However,the application of PMo12 as electrode in this field is limited due to its poor conductivity and easily leaching greatly.To improve the properties of PMo12,we synthesized the composite material of PMo12 with excellent conductive material of graphene.Among the POM/nanocarbon composite materials,the PMo12/graphene stands out owing to its large surface area,excellent mechanical properties and thermal stability of graphene.In this study,electrochemically active PMo12 was combined with graphene(that is,GO and N-doped rGO)and the resultant PMo12/NrGO was investigated to as anode material for lithium ion battery(LIB)and supercapacitor.The design strategy utilized the electrochemical properties of PMo12 and the excellent conductivity of graphene,which were fabricated by using the ionic liquid(IL)and polyaniline(PANI)as linker.These works included the following parts:1.PMo12 was grown onto the GO by using IL as linker.The IL was covalently linked with the GO through reaction of Si(OEt)3 on IL with-OH groups on GO.After that,PMo12 was homogeneously dispersed onto GO by exchanging with the PF6-.The as-prepared PMo12/IL-GO nanocomposite was fully characterized by FT-IR,Raman,SEM,TEM,HRTEM,TG-DTA and XPS,demonstrating the formation of the composite material.Application of PMo12/IL-GO nanocomposite as anode materials of LIB,shows high discharge capacity 980 mAh·g-1(at current density of 100 mA·g-1)and good stability as anode material for LIB.2.The PMo12/PANI/NrGO-1 nanocomposite material was prepared by one-pot oxidation-reduction reaction,and fully characterized by FT-IR,Raman,SEM TEM,HR-TEM and XPS.The resultant PMo12/PANI/NrGO-1 was used as supercapacitor exhibits high specific capacitance 702 F·g-1 at current density of 1 A·g-1,which is much higher than N-rGO of 325 F·g-1.In addition,this composite material shows excellent stability after 2000 cycles with 87%specific capacitance.