关键词: 再生能源, 分离, 液流电池, 膜

Abstract:

Flow battery has outstanding features of high safety, high cost performance, long lifespan and great environmental friendliness, very suited for large-scale energy storage. A typical flow battery is composed of the electrodes, the membrane, the electrolytes and so forth. Among them, a membrane plays the role in avoiding the crossover of active species in different electrolytes while conducting charge carriers to form a complete electrical circuit simultaneously. Consequently, the membrane properties and price exert significant effects on the performance and cost of flow batteries. However, the commonly used commercial per-fluorinated sulfonated ion exchange membranes have low selectivity and high cost, while the highly selective and low-cost non-fluorinated ion exchange membranes have poor chemical stability because of the existence of ion exchange groups. As a result, porous ion conducting membrane without ion exchange groups was introduced into flow batteries, which was based on the “ion sieving conducting” mechanism to avoid the transference of active species and conduct charge carriers at the same time. Consequently, porous ion conducting membranes generally have high stability, high selectivity and high conductivity. Moreover, up to now, many modifying strategies have been proposed to tune the structure and optimize the performance of porous ion conducting membranes. The large-scale quantity production of high-performance and low-cost porous ion conducting membranes has also been achieved. In this review, various modifying strategies of porous ion conducting membranes will be overviewed based on their research and development in flow batteries. Therefore, this review will provide significant theoretical instructions to further tune the structure and optimize the performance of porous ion conducting membranes in flow batteries.

Key words: renewable energy, separation, flow battery, membrane