fist patented by one of the founders of Cellennium in 1978, the vanadium flow battery uses vanadium sulfate on both sides of the membrane in the electrochemical cells. The storage of electricity is possisble because of the unique properties of the vanadium atom, which can be electrically charged by removing two, three, four, or five electrons. The unique architecture of Cellennium's battey allows it to not only be a cheap and reliable energy storage device, but also to function as a power convesion ` device capable of transforming both voltage and frequency of the electricity input.