In one aspect, disclosed herein is a redox flow battery (RFB). The battery generally comprises: a positive electrolyte comprising a first metal ion, a negative electrolyte comprising a second metal ion, an ion exchange membrane positioned between the positive electrolyte and the negative electrolyte, wherein said membrane is configured to restrict and/or prevent the passage of the first metal ion and/or the second metal ion therethrough, and said membrane is configured to maintain ionic conductivity between the positive electrolyte and the negative electrolyte.

In another aspect, disclosed herein is a method for storing electricity. The method generally comprises preparing a positive electrolyte that comprises a first metal ion; preparing a negative electrolyte that comprises a second metal ion; placing an ion exchange membrane between the positive electrolyte and the negative electrolyte, wherein said membrane is configured to restrict and/or prevent the passage of the first metal ion and/or the second metal ion therethrough, and said membrane is configured to maintain ionic conductivity between the positive electrolyte and the negative electrolyte. In some aspects, the method for storing electricity generally comprises preparing the redox flow battery as described elsewhere herein.