Todays, the reinforcement or modification of each

Todays, the storage devices
have greatlyincreasedwiththe rapid developmentofthemodern electronic industry
1–4.Sustainable energy storage devices are one of the most important research
areas in the world today, for technology development. Thus, an efficient energy
storage method is a technological challenge to ensure the availability of
energy 2. The Supercapacitors are selected as promising
applicants for energy storage due to their higher powerdensity,faster
charge-discharge mechanism, longer life cycles and simpler principles compared
with the traditional batteries. The NiO is a promising
alternative transition metal because it is easily available, has a low cost and
good electrochemical stability, and is a p-type semiconductor. Recently, the
advances in the synthesis of the NiO nanostructure have caused it to receive
more attention.Several methods were used to improve the capacitance behavior of
NiO such as, template method 17, 18, composite despite , and mixed-oxide composites 19, 20.Several transition metal oxide/graphene composites, such as
NiO/grapheme 24, Co3O4/grapheme 25, MnO2/grapheme 26, andFe3O4/grapheme 27, composites have been synthesize and each of them showed
improved capacitive performances due to their enhanced electrical conductivity
and increased active surface area. As an ideal matrix, graphene possesses many
fascinating properties, such as high electrical conductivity, large specific
surface area, high mechanical flexibility, with pronounced thermal and chemical
stability 21, 22. Extensive research have been conducted on fabrication of
graphene-transition metal oxides composites for supercapacitor applications, which
can combine the advantages of both components and may generate special
properties by the reinforcement or modification of each other 23. The present of grapheme nanosheets act as a flexible
two-dimensional support for the NiO-NPs, result in improved pseudocapacitve
behavior. The integration of graphene can help in preventing the agglomeration
of NiO-NSs, achieving  higher surface
area and also good life cycle and excellent rate capability24.