Flow batteries are promising for energy storage due to their high safety, high reliability, long cycle life, and high efficiency.
The development of commercial-scale flow batteries for long-duration energy storage requires to reduce the cost of flow batteries, especially the cost of ion-exchange membranes.
Recently, a research group led by Prof. LI Xianfeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) realized pilot-scale synthesis and roll-to-roll manufacturing of hydrocarbon membranes with high-performance in alkaline-based flow batteries.
This work was published in Joule on March 21.
The researchers realized the kilogram-level synthesis of sulfonated poly(ether-ether-ketone) (SPEEK) polymer and demonstrated the pilot-scale roll-to-roll synthesis of SPEEK membrane and their applications in alkaline-based flow batteries.
They found that the rigid skeleton and dispersive cation exchange groups enabled the high stability of the membrane in alkaline media, and could confine O-containing species (H 2 O, OH - , etc.) inside the membrane, resulting in the formation of continuous hydrogen-bonding networks. This favored the dissociation of H + in H–O–H (H 2 O) and transfer from H 2 O to adjacent OH - ions through a Grotthuss mechanism, thus providing a high OH - conductivity in SPEEK.
The membrane was integrated in alkaline zinc-iron flow battery stack with power up to 4 kW, with a high energy efficiency of 85.5% operated at 80 mA/cm 2 .
This work was supported by the National Natural Science Foundation of China, CAS Engineering Laboratory for Electrochemical Energy Storage, and the Youth Innovation Promotion Association of CAS.
Joule
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Low-cost hydrocarbon membrane enables commercial-scale flow batteries for long-duration energy storage
21-Mar-2022