The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing the first practical, high capacity desalination cell using bismuth-based chloride-storage electrodes.
Access to fresh water is a pressing geopolitical issue and technological challenge. Desalination is a potentially viable solution considering the abundance of seawater on Earth. While reverse osmosis is an advanced science, the process requires significant electrical input. A promising alternative is capacitive deionization (CDI), which removes salt ions by capturing them in a double layer of high surface area electrodes.

CDI cells have been limited primarily to brackish water and are less effective at removing salt from concentrated sources like ocean water. To increase capacity, researchers know that salt ions can be stored in the bulk of the electrode through the formation of chemical bonds. Moreover, if the cell can store and release salt ions through the charging/discharging cycle and recover some of the energy in the process, it could be considered a rechargeable ‘desalination battery’ with the potential to slash overall energy input.

To date, attempts to engineer such a cell have relied on costly silver as the chloride-storage electrode. The commercial viability of the technology depends on the development of more efficient, stable and practical electrode material. Read the full description here.