Zinc iodine flow battery energy density increases significantly

The reporter learns from dalian institute of chemical physics of Chinese Academy of Sciences, of the energy storage technology research at Li Xianfeng researcher, zhang hm researcher leadership team innovation put forward single flow battery is zinc, iodine, single zinc iodine flow of electrolyte the utilization rate of nearly 100%, which significantly improves the energy density of the battery. Research results were published online on energy and environmental science.

large-scale energy storage technology is the key technology to realize large-scale renewable energy use, flow battery with high safety, long cycle life, high efficiency, etc, is one of the first choice for large-scale energy storage technology. Zinc iodine flow cell is a kind of flow battery technology, due to their high energy density, and environment friendly advantages, in recent years, more and more attention.

in the previous studies, the research team by optimizing the zinc iodine flow battery electrolyte composition and membrane material, improving the cycle life and power density. However, in order to avoid zinc iodine flow battery electrolyte caused by internal blocking utilization is still relatively low problem to be solved.

unlike traditional zinc iodine flow batteries, zinc, iodine, single flow battery anode side only has flow circulation system, the positive electrolyte solution directly fixed in the anode chamber. Because the zinc iodine single flow battery is very solid, no flow circulation system, so there is no problem of fluid pipeline and the blocking of the pump, thus can charge to solid iodine elemental iodine ions, makes the utilization rate of the electrolyte increased from about 50% to nearly 100%, the energy density of the battery from the top 80 wh/L before increase to 205 wh/L.

in addition, the researchers through the adoption of porous carbon felt as electrode, guarantees the zinc iodine single flow battery with high power density ( 0. 1W/cm2） 。 The experimental results show that the zinc iodine single flow batteries can be under the current density of 80 ma/cm2, stable operation of more than 500 - cycle, there is no obvious attenuation performance. These studies for the development of new high energy density flow battery system provides an important reference.