PORTEFEUILLE

The vanadium redox flow battery is the most promising technology for large-scale energy storage due to its long lifetime, high safety and flexible design. However, its efficiency is largely limited by the use of ion exchange membranes, which are “borrowed” from other technologies. This problem was solved at Paul Scherrer Institut with the invention of a new membrane technology called amphoteric membrane, that improves the round-trip efficiency of vanadium flow batteries by up to 15%. The patent-pending technology can be also used in electrolysers and fuel cells and is currently commercialized by Gaia Membranes under the Amphion™ brand.

The ion exchange membrane (IEM) sector saw its last major innovation over 50 years ago with the invention of the currently world-leading Nafion™ technology. The breakthrough innovation that this project focuses on represents a paradigm shift in the science of IEMs which had been theorised for decades but never satisfactorily achieved in practice.
IEMs based on the patent-pending Amphion™ technology can be tailored to optimally fulfil the target electrochemical application, whereas with competing IEM technologies it is the application that needs to be tailored to the limited functionalities of the membrane. In the case of VRFBs, the benefit is there for anybody to see: Amphion™ membranes are the first and only technology to enable a balanced transport of ions and water across the membrane so that VRFB can operate with a stable capacity throughout their lifetime.

Gaia Membranes AG was founded in March 2019 in response to strong customer interest. Since the start of the project, the team achieved important development goals such as a holistic and scalable quality control process, the long-term stability, better handling of the membrane product for automated stack assembly and the replacement of toxic intermediates. Another major milestone was achieved regarding the scale-up of the membrane production, which was mainly conducted manually in the lab-scale prior to this project. The production process was successfully validated together with a potential production partner on a semi-automated roll-to-roll production line. At present, the team is demonstrating the technology in close collaboration with potential customers and evaluating industrial partners to bring its outstanding technology to scaled-up production.

Accelerated Stress Test Method for the Assessment of Membrane Lifetime in Vanadium Redox Flow Batteries. CS Appl. Mater. Interfaces (2019)
Tackling Capacity Fading in Vanadium Redox Flow Batteries with Amphoteric PBI/Nafion Bilayer Membranes. PChemSusChem (2019)
Tackling capacity fading in vanadium flow batteries with amphoteric membranes. Journal of Power Sources (2017), 368, 68-72.