Graphene oxide may be a better choice as an electrode for supercapacitors than graphene because it exhibits higher capacitance, shorter processing time and is cheaper than graphene, say researchers from China.
Supercapacitors are promising energy storage devices for electric vehicles because of their high power densities and long cyclic lives.
Graphene, a two-dimensional nanosheet of graphite, has been the material of choice for supercapacitors because it possesses superior electrical conductivity, a high theoretical surface area and chemical tolerance. But, owing to the unavoidable aggregation of graphene nanosheets, the surface area is usually much lower than the theoretical one and its capacitance is generally in the range 100–200 F g-1.
Graphene oxide is an intermediate during the synthesis of graphene. Despite the fact that some graphene oxide-based nanocomposites have performed well in supercapacitors, it has been said that graphene oxide is not suitable as an electrode material because of its poor conductivity, but the team contradict this with their findings.
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What Is the Choice for Supercapacitors: Graphene or Graphene Oxide?
B Xu, S Yue, Z Sui, X Zhang, S Hou, G Cao and Y Yang
Energy Environ. Sci., 2011, DOI: 10.1039/c1ee01198g