Investigation on graphene based nanocomposite materials for energy storage application

Abstract

Nowadays demand in efficient energy storage system is significantly focused by carbon based nanomaterials for future societal and environmental needs. Graphene is one of the derivatives of Sp2 hybridized carbon nanomaterials. Since its discovery it plays an important role in functionalising with other molecules for various properties (optical, electrical, mechanical, and electrochemical) and applications. Due to its high surface area graphene has been explored much to convert energy storage electrode materials into materials with considerably improved electrochemical properties and applications. Perovskite nanomaterials are in wide use due to their superior dielectric, magnetic and optical properties. When Perovskite nanomaterials are brought into nanoscale features like nanoparticles or nanorods or nanowires with well-controlled size and shape, they exhibit improved or completely new kind of properties compared to their bulk structures. These fascinating properties certainly enable them to be useful for various applications such as, supercapacitors, solid oxide fuel cells, sensors, environmental catalyst and possibly in spintronics based applications etc. Moreover, the high electronic and ionic conductivity exhibited by columbites enhance their composite behaviour and has enabled them to act as active electrode materials energy conversion process. Graphene based nanocomposites at low loading of graphene exhibits enhanced property in its multifunctional aspects when compared to conventional materials and their composites. They are also lighter in weight with simple processing. This helps in various cost effective multifunctional applications. Recently, niobate compounds have attracted much attention due to their ferroelectric, piezoelectric, pyroelectric electro-optical, photorefractive and photocatalytic properties. However, the electrochemical oxidation and reduction property of niobates in supercapacitors and lithium ion battery have not yet been explored much. The present work describes a scalable synthesis of novel and unique structural composite materials such as reduced graphene oxide/barium niobate (RGOBN), reduced graphene oxide/strontium pyro niobate (RGOSPN), reduced graphene oxide/cadmium niobate (RGOCN) and reduced graphene oxide/magnesium niobate (RGOMN). These nanostructured composite materials were characterized physicochemically and electrochemically as a new kind of bi-functional catalyst for energy storage devices. newline