A new aqueous redox flow battery with multiple redox couples is developed based on a vanadium redox flow battery by adding Ti and Mn ions to both negative and positive electrolytes to form a V-Mn-Ti/V-Mn-Ti system. In this system, V and Mn act as redox couples at the positive electrode and V and Ti at the negative electrode. Since there are multiple redox couples in both negative and positive electrolytes, the energy density of the V-Mn-Ti/V-Mn-Ti system reaches to 39.3 Wh L−1, which is higher than single redox couple systems such as the V/V and V/Mn systems by 86% and 27%, respectively. In addition, since the negative and positive electrolyte compositions are the same, the problem of electrolyte contamination due to ion crossover can be solved through rebalancing. After rebalancing, the energy density is restored to 98% of the initial performance. Based on the experimental results, the new V-Mn-Ti/V-Mn-Ti redox flow battery is expected to be a promising candidate for large-capacity energy storage devices.
Bibliographical noteFunding Information:
This work was supported by the Energy Efficiency & Resources of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Trade, Industry & Energy (MOTIE) (No. 20152020106550) and the Human Resources Program in Energy Technology of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20174010201640).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry