Development of carbon composite bipolar plate (BP) for vanadium redox flow battery (VRFB)

A vanadium redox flow battery (VRFB) is one of the most promising energy storage systems (ESSs) due to its safety, durability and scalability. However, high cost of its components has been obstacle for commercialization of VRFB. Especially, bipolar plates (BPs) which are the main components of VRFB, are fabricated using graphite, which increases not only its manufacturing cost, but also decreases the reliability of VFRB, especially for the large area BP due to the brittleness of graphite although the graphite has high electrical conductivity and chemical stability. In this work, a carbon composite BP for the VRFB has been developed optimally considering its electrical as well as chemical stabilities against strong acids. Charge/discharge tests of the VRFB using the developed carbon composite BPs were performed to observe its energy and voltage efficiencies, from which the durability of the composite BP was estimated.