High-performance seawater magnesium batteries for marine waters

Given the growing attention on the environmental challenges, ocean research and marine life, a pursuit of greener energy resources and in depth research on remote locations of the ocean, SeaMag project has chosen to focus on providing a solution for a sustainable power source for autonomous ocean systems. Polar regions are at risk as they are extremely sensitive to climate change and their biodiversity is fragile. At the same time, these remote regions remain vastly unexplored and poorly documented. For example the JPI Oceans identifies a host of vital areas in its strategic and innovation agenda for 2015-2020. In these areas, advancements are reliant on not only the new technology and sensors but on a reliable, inexpensive, energy supply such as the SeaMag battery. During the last period of the project, focus point have been to optimize and enhance the SeaMag battery system features, from the electronics to the composition of the various items such as the additives. The additives have been tested in several arrangements, together with the cathode and anode, in the complete battery system setup as well as in a lab scale version. From the tests and results, we have carefully selected the best working additive from its best operational results. The battery setup has been optimized to provide a successful output, considering the low voltages created. The project was ended with a working battery system, providing a successful power output, however with some challenges. Due to challenges for electronics, and the low voltages we have made changes all the way to the end, being able to finally provide a working battery, providing power for two underwater sensors during our demonstration.

The SEAMAG project developed cell materials beyond the state-of-the-art such as high-performance Mg-Ca alloys, non-toxic electrolyte additives, Sulfosalicylic acid that can be tailored to different operating currents, and carbon-based air cathodes that show significantly low over the potential for oxygen reduction reaction. The ability to use aqueous electrolytes such as saltwater (and direct seawater) makes these batteries inherently safe. A compact cell design has been developed and the final demonstration showed operation of four SEAMAG batteries separately and collectively using real-time subsea devices. The cells were functioning successfully. The project has a significant short-term impact on materials development for metal-air batteries, such as the ORR catalyst, where one of the partners already working with the catalyst supplier to investigate its potential for zinc-air batteries and fuel cells. SEAMAG project started with TRL3 and ended with TRL6, with the cell demonstration.

The European Union is increasingly focused on healthier, cleaner and more productive seas, sparking more research within the marine sector (biodiversity, climate change, marine energy). For example the JPI Oceans in its strategic research and innovation agenda 2015-2020 identifies a host of strategic areas in which advancements are reliant on not only the new technology and sensors but on a reliable, inexpensive, energy supply such as the SeaMag battery. Growing environmental concerns is leading to more strict EU regulations in regards with man-made activities and is enforcing measures such as the monitoring of abandoned oil wells, evaluating water quality and tracking enviromental changes associated with global warming. Moreover, safer and cheaper batteries may boost marine research in sensitive regions where the deployment of lithium batteries is challenging. Polar regions are at risk as they are extremely sensitive to climate change and their biodiversity is fragile. At the same time, these remote regions remain vastly unexplored and poorly documented. For example the JPI Oceans identifies a host of vital areas in its strategic and innovation agenda for 2015-2020. In these areas, advancements are reliant on not only the new technology and sensors but on a reliable, inexpensive, energy supply such as the SeaMag battery.