Studies of the Feasibility of a Ce[sup 4+]/Ce[sup 3+]-V[sup 2+]/V[sup 3+] Redox Cell

A novel redox cell system was investigated; it was composed of the Ce 4 + / Ce 3 + couple, which replaced the V 5 + / V 4 + couple of the all-vanadium redox cell, and the V 2 + / V 3 + couple. The Ce 4 + / Ce 3 + system showed favorably better charge-discharge properties of having both higher energy efficiency and coulombic efficiency in 0.5 mol dm −3 H 2 SO 4 solution compared to any other concentration. CAP periodic charge-discharge measurements were conducted under constant current and constant load with the proposed Ce-V redox cell. The results indicated that the coulombic efficiency remained around 90% and the discharge voltage stabilized between 1.5 and 1.2 V. But as the cycle numbers increased, the discharge capacity declined a bit and a better result might be expected by improving the separator. In short, results from this preliminary study suggest that the Ce-V combination is a promising system for redox flow-cell applications and is worthy of further study.