Quinone-Based Flow Battery with Increased Open Circuit Voltage

Tuesday, 7 October 2014: 14:00
Sunrise, 2nd Floor, Star Ballroom 2 (Moon Palace Resort)
M. R. Gerhardt, M. P. Marshak, B. Huskinson (Harvard School of Engineering and Applied Sciences), R. G. Gordon (Department of Chemistry and Chemical Biology, Harvard University), and M. J. Aziz (Harvard School of Engineering and Applied Sciences)
Quinone-based flow batteries exhibit rapid redox kinetics, contain no electrocatalyst and use very inexpensive redox active materials [1]. Consequently, they appear to be very attractive candidates for inexpensive, large-scale electrical energy storage. We compare the performance of several substituted quinone/hydroquinone redox couples in an aqueous flow battery. We show that various substitutional groups can alter the electrochemical properties of the quinone, which in turn affects the performance of the flow battery. One substituted quinone at the negative electrode, when combined with Br2/HBr at the positive electrode, exhibits an open circuit voltage exceeding 1.0 V and a peak galvanic power density exceeding 0.24 W/cm2when fully charged.

Fig. 1.  Polarization plot (a) and galvanic power densities (b) of a substituted quinone-bromine flow battery at various states of charge (SOC).  The electrodes are Toray carbon paper with no electrocatalyst. The membrane is Nafion 212. The negative side is 0.5 M substituted quinone in 1 M sulfuric acid. The positive electrode is 1.5 M hydrobromic acid, 0.25 M bromine.