Aluminum Batteries Close to Commercial Success

I know it sounds a bit geeky, but we at MetalMiner love to hear about new applications for aluminum. This latest development is not exactly going to change the global demand-supply balance for aluminum but it does showcase one of the many qualities the metal possesses, one which is sometimes overshadowed by aluminum’s lightweight or easy formability.

Aluminum’s use in batteries is nothing new. Aluminum–air batteries have been a topic of research for some time and work by producing electricity from the reaction of oxygen in the air with aluminum. They have one of the highest energy densities of all batteries, but they are not widely used because of problems with high anode cost and by-product removal when using traditional electrolytes.

Considerable research has also gone into aluminum-ion batteries yet technical problems remain that have slowed rollout of a commercial product. But an Economist article details how a firm in Massachusetts, called Open Water Power, (OWP), is developing a battery specifically for Unmanned Underwater Vehicles but which may have applications much wider afield. OWP’s battery uses an aluminium anode and a nickel cathode with an electrolyte made of seawater that has potassium hydroxide dissolved in it. The potassium hydroxide has benefits increasing the number of ions able to carry charge but in addition it dissolves the aluminium hydroxide formed at the cathode allowing it to be removed from the cell without clogging up the anode.

The attraction for OWP in the UUV market is that any new technology would replace lead-acid batteries favoured over lithium ion because the latter has a risk of catching fire. UUV’s used in the oil and gas industry may have a range of only about 10 nautical miles due to the lead-acid batteries that power them, but the firm believes their new design could increase this to 110 nautical miles. Not surprisingly the military are also interested as are research institutes desperate to extend the range of power crewed deep diving submersibles.

The batteries stability, use of saltwater, and power density over lead acid make it ideal for marine applications but in truth even as a replacement for lithium ion batteries it has merit where a fire risk is particularly sensitive. Tests this summer will prove the technology’s maturity and in time could usher in a rival to the old lead acid battery and in some circumstances even the lithium iron.