Sustainable Membranes for Redox Flow Batteries
Amirreza Khataee
KTH Royal Institute of Technology
Redox flow batteries (RFBs) are promising technologies for long-duration energy storage mainly due to flexibility in design and operation. As the critical component in RFBs, the membrane significantly affects capital costs and power density. Yet the poor ion selectivity and the fluorinated backbone of commercial membranes like Nafion have become a substantial barrier in commercializing RFBs. We have successfully fabricated and tested sustainable proton- and anion exchange membranes using a poly(p-terphenyl) backbone. Also, we combined anionic and cationic features in a single membrane called a zwitterionic membrane. The results showed that the membranes mentioned above showed competitive performance in an RFB system compared to Nafion 212. An interesting finding is that a proper polymer design and morphology can guarantee good electrochemical performance. Our results represent a critical step for developing novel formulations of ion exchange membranes for RFBs.