Towards high power density aqueous redox flow batteries

With the increasing penetration of renewable energy sources in the past decades, stationary energy storage technologies are critically desired for storing electricity generated by non-dispatchable energy sources to mitigate its impact on power grids. Redox flow batteries (RFBs) stand out among these technologies due to their salient features for large-scale energy storage. The primary obstacle to the successful industrialization and broad deployment of RFBs is now their high capital costs. A feasible route to cost reduction is to develop high-power RFBs, since the increase in power performance has a pronounced impact on the cost of RFB systems. In this review, an in-depth inspection of the power performance of RFBs is presented. Perspectives for the future development of high-power RFBs along with implementable strategies addressing both the intrinsic and extrinsic limiting factors are summarized, which are expected to provide useful references steering the further improvement in the power density of RFBs.