A novel (I+/I-2)/vitamin C vs. V4+/V5+ semi-vanadium redox flow battery (semi-VRFB) with iodine, vitamin C, and V4+/V5+ redox couples, using multiple electrodes was investigated. The electrodes, Ni-P/carbon paper and Ni-P/TiO2/carbon paper, were modified by the electroless plating method and sal-gel process. The electrochemical characteristics and the performance of the semi-VRFB were verified by the cyclic voltammetry method and a charge-discharge test. This study shows modified electrodes can improve the reversibility and symmetry of the oxidation-reduction reaction of the semi-VRFB system, and effectively raise its storage ability. The coulomb efficiency of the semi-VRFB system is close to 96%, which is higher than the all-VRFB. The semi-VRFB system can reduce the amount of vanadium salt, therefore, it is not only a reduction in cost, but also has a great potential for the development of energy storage systems. (C) 2014 Elsevier Ltd. All rights reserved.