Bipolar Membranes with an Electrospun 3D Junction
A bipolar membrane (BPM) is made up of laminated films of anion (positively charged) and cation (negatively charged) exchange polymers. These membranes are currently used in electrodialysis separations for waste water clean-up/reclamation and in various industrial processes. Recently, BPMs have also been examined for use as a self-hydrating membrane in a hydrogen fuel cell. Over the past 75 years, there has been no substantial change in the basic design of commercial BPMs, which limits their range of application.
Project Innovation + Advantages:
The Vanderbilt University team will develop a new bipolar membrane featuring a three-dimensional water splitting or water formation junction region, prepared by an electrospinning process. The team’s membrane will allow for higher current density operation as compared to conventional BPMs while maintining a low operating voltage, long-term durability, and high separation efficiency. These membranes will be useful in electrodialysis, electrolysis, and fuel cell applications.
Based on preliminary experiments, it is possible to operate a 3D junction BPM at current densities more than one order of magnitude greater than those achievable with the best commercially available films, with no sign of membrane degradation. Stack size is reduced accordingly.
Such high current density operation is truly transformative with enormous commercial benefits in terms of opening up new applications for BPMs (e.g., photochemical CO2 capture and conversion), ensuring U.S. leadership in this field.
The use of a BPM in a high-power, self-hydrating fuel cell membrane-electrode-assembly that does not require a platinum-based cathode and reduces the need for humidification will make hydrogen fuel cells commercially attractive. Clean energy storage and conversion technologies will allow high for accelerated penetration of emissions-free renewable power technologies into transportation and the electric power infrastructure.
The new BPMs will be 10 times less expensive and offer 10 times better performance than current technologies, making water reuse and industrial electrodialysis separations more economical.