Bipolar Membranes with an Electrospun 3D Junction

Technical Report · Thu Nov 09 04:00:00 EST 2023

DOI:https://doi.org/10.2172/2516710· OSTI ID:2516710

Pintauro, Peter ^[1]; Wycisk, Ryszard ^[1]; Yang, Zezhou ^[1]; Mondal, Abhishek ^[1]; Powers, Devon ^[1]

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1. Vanderbilt Univ., Nashville, TN (United States)

Freestanding bipolar membranes (BPMs) with an entirely new and transformative morphology were fabricated and characterized. The key disruptive design element was a water-splitting/water-generation junction layer of finite thickness composed of interwoven and interlocking electrospun anion-exchange polymer (AEP) fibers and cation-exchange polymer (CEP) fibers. Methods were developed to sandwich the 3D junction layer between two pre-formed dense AEP and CEP films., with the closure of all interfiber voids, where the processing steps are easily incorporated into a commercial roll-to-roll membrane manufacturing scheme. A series of membranes were made using different polymers and junction layers to identify the optimum morphology and composition for water-splitting and water-generation applications. For water splitting, the 3D junction BPMs worked remarkably well with operating current densities at/above 1.0 A/cm2 (10X greater than commercial BPMs) at a transmembrane voltage drop of only 1.1 V. In water generation mode, the 3D junction BPMs operated at 0.5 A/cm2, a world-record current density. The membranes were found to exhibit outstanding durability and can be manufactured at scale for low cost. The high operating current densities and stable long-term operation are due to the 3D junction layer design, where there is a high interfacial area for water splitting or water generation reactions and where the interlocking fibers prevent delamination of the outer films. These new BPMs are ideal candidate materials for both existing water-splitting electrodialysis separations and new electrochemical processes, such as large-scale direct air capture of CO₂, reactors for CO₂ reduction, self-hydrating fuel cells, and redox flow batteries.

• Research Organization: Vanderbilt Univ., Nashville, TN (United States)
• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• DOE Contract Number: AR0001035
• OSTI ID: 2516710
• Report Number(s): AR0001035
• Country of Publication: United States
• Language: English

Related Subjects

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32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
36 MATERIALS SCIENCE
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