Spectrum recently published a post about a new lithium sulfur battery technology specifically aimed at electric aviation applications. Although many electric cars could benefit from the new technology, aircraft are particularly sensitive to heavy batteries and lithium-sulfur batteries can weigh much less than modern batteries of equivalent capacity. The Spectrum post is from Oxis Energy which is about to fly tests with the new batteries which they claim has twice the energy density of conventional lithium-ion batteries. The company also claims that the batteries are safer, which is another important consideration when flying through the air.
The batteries have a cathode made of aluminum foil covered with carbon and sulfur – which prevents the use of cobalt, a cost driver in traditional lithium cell chemicals. The anode is pure lithium foil. Between the two electrodes is a separation in an electrolyte. The company says the batteries go through multiple stages as they discharge, forming various chemical compounds that continue to produce electricity through chemical action.
The safety factor is due to the fact that, unlike lithium-ion cells, the new batteries do not form dendrites that shorten the cell. The cells degrade over time, but not in a way that is likely to cause a short circuit. However, ceramic coating may provide protection against this degradation in the future, which would be another advantage compared to traditional lithium batteries.
We see a lot of exciting battery announcements, but we rarely see real products with them. Time will tell if the Oxis and similar batteries based on this technology will take root.
