Researchers at Carnegie Mellon University have stumbled upon a solution to the “sudden death” phenomenon in lithium-air battery chemistry: just add water!
New rechargeable battery technology is constanty in development, as we’ve spent lots of time covering here, from solid-state lithium-ion battery technology to metal-air battery chemistry. Many of these technologies, such as lithium-air battery technology, hold the promise of more energy storage, cheaper energy storage, or both, but often don’t make it to production. This, of course, could be for a number of reasons, from basic reliability and durability problems to unrealistic expectations.
In comparison to current lithium-ion battery technology, lithium-air could hold up to twice the energy, but suffers from a phenomenon known as “sudden death,” which reduces its lifespan significantly. Like all lithium-based batteries, the lithium-air battery uses a lithium anode, but eliminating the hard-carbon cathode, which results in a lighter battery. Atmospheric oxygen drives the reaction, but creates a problem as it does so, leaving a lithium peroxide (Li2O2) film on the anode. The film prevents any further reaction, “killing” the battery after just a short period of time.
Researchers at Carnegie Mellon University admit that it’s a temporary solution, finding that the addition of water dissolves the lithium peroxide film that develops on the lithium-air battery anode. By eliminating the sudden-death problem, researchers were forced to recalculate lithium-air’s energy storage capacity. With the lithium peroxide barrier removed, the new lithium-air formulation is up to 500% more energy dense than previously. Of course, there’s still the problem of the water itself adding weight and dissipating, so more development is needed to make lithium-air batteries comparable or better than lithium-ion.