Drs Manickam Minakshi and Danielle Meyrick at Murdoch University in Australia have developed a water based sodium ion battery. This is another version of the battery technology being developed by Aquion Energy about which I have previously written. The announcement article reveals only a small amount of information about the battery design:
Anode: manganese dioxide (MnO2)
Cathode: an olivine sodium phosphate.
They are using the same anode material as Aquion. The substitution of an olivine sodium phosphate for activated carbon is interesting. Olivine is an extremely common mineral with the formula (Mg,Fe)2SiO4. Carbon is an abundant material, but activated carbon is not particularly cheap to produce. Therefore the possibility exists that the new cathode might end up having lower manufacturing costs. However, the costs and performance for this battery design are conjectural since it is just exiting the research phase of development. Furthermore using phosphorus as a key electrode material may not be great long term plan, since this element is vital for food production and supplies could become problematic in a time period of several decades.
The article claim that the energy density of this design is not particularly high, so that stationary applications (i.e. grid storage) are being targeted for commercialization rather than mobile application (i.e. electric automobiles). Performance characteristics such as cell voltage, round trip efficiency and cycle life are not mentioned.
Aug 18, 2012
Energy Storage News
rogerkb [at] energystoragenews [dot] com