Free-standing graphene/vanadium oxide composite as binder-free electrode for asymmetrical supercapacitor.

See more Vanadium products. Vanadium (atomic symbol: V, atomic number: 23) is a Block D, Group 5, Period 4 element with an atomic weight of 50.9415. The number of electrons in each of Vanadium's shells is 2, 8, 11, 2 and its electron configuration is [Ar] 3d³ 4s². The vanadium atom has a radius of 134 pm and a Van der Waals radius of 179 pm. Vanadium was discovered by Andres Manuel del Rio in 1801 and first isolated by Nils Gabriel Sefström in 1830. In its elemental form, vanadium has a bluish-silver appearance. It is a hard, ductile transition metal that is primarily used as a steel additive and in alloys such as Titanium-6AL-4V, which is composed of titanium, aluminum, and vanadium and is the most common titanium alloy commercially produced. Vanadium is found in fossil fuel deposits and 65 different minerals. Vanadium is not found free in nature; however, once isolated it forms an oxide layer that stabilizes the free metal against further oxidation. Vanadium was named after the word "Vanadis" meaning goddess of beauty in Scandinavian mythology.

See more Carbon products. Carbon (atomic symbol: C, atomic number: 6) is a Block P, Group 14, Period 2 element. The number of electrons in each of Carbon's shells is 2, 4 and its electron configuration is [He]2s² 2p². In its elemental form, carbon can take various physical forms (known as allotropes) based on the type of bonds between carbon atoms; the most well known allotropes are diamond, graphite, amorphous carbon, glassy carbon, and nanostructured forms such as carbon nanotubes, fullerenes, and nanofibers . Carbon is at the same time one of the softest (as graphite) and hardest (as diamond) materials found in nature. It is the 15th most abundant element in the Earth's crust, and the fourth most abundant element (by mass) in the universe after hydrogen, helium, and oxygen. Carbon was discovered by the Egyptians and Sumerians circa 3750 BC. It was first recognized as an element by Antoine Lavoisier in 1789.