Graphene-Based Materials for Supercapacitor

Graphene, a one-atomic-thick film of two-dimensional nanostructure, has piqued the attention of researchers due to its superior electrical conductivity, large surface area, good chemical stability, and excellent mechanical behaviour. These extraordinary properties make graphene an appropriate contender for energy storage applications. However, the agglomeration and re-stacking of graphene layers due to the enormous interlayer van der Waals attractions have severely hampered the performance of supercapacitors. Several strategies have been introduced to overcome the limitations and established graphene as an ideal candidate for supercapacitor. The combination of conducting polymer (CP) or metal oxide (MO) with graphene as electrode material is expected to boost the performance of supercapacitors. Recent reports on various CP/graphene composites and MO/graphene composites as supercapacitor electrode materials are summarised in this chapter, with a focus on the two basic supercapacitor mechanisms (EDLCs and pseudocapacitors)

Antiferro quadrupolar ordering in Fe intercalated few layers graphene

The π electron cloud above and below the honeycomb structure of graphene causes each carbon atom to carry a permanent electric quadrupole moment which can attach any cation to impart interesting physical properties. We have synthesized Fe intercalated graphene structures to investigate tunable magnetic properties as a result of this chemical modification. An interesting antiferro quadrupolar ordering is observed which arises due to a coupling between magnetic dipole moment of Fe and electric quadrupole moment on graphene surface. In contrast to antiferromagnetic Neel temperature (TN), here the ordering temperature (TQ) increases from 35.5 K to 47.5 K as the magnetic field is raised upto 1 Tesla