Chemists' Discovery Could Lead To Greatly Improved Energy Storage

Canadian researchers this week announced the discovery of a battery reaction that could pave the way for the "holy grail of electrochemical energy storage."

The key lies in Nazar's group discovery of the so-called proton phase transfer catalyst. By isolating its role in the battery's discharge and recharge reactions, Nazar and colleagues were not only able to boost the battery's capacity, they achieved a near-perfect recharge of the cell. When the researchers eliminated the catalyst from the system, they found the battery no longer worked. Unlike the traditional solid-state battery design, a metal-oxygen battery uses a gas cathode that takes oxygen and combines it with a metal such as sodium or lithium to form a metal oxide, storing electrons in the process. Applying an electric current reverses the reaction and reverts the metal to its original form. (Image: University of Waterloo)Canadian researchers this week announced the discovery of a battery reaction that could pave the way for the "holy grail of electrochemical energy storage."

Chemists from the University of Waterloo successfully isolated a substance called the proton phase transfer catalyst, which allowed them to increase the capacity of a sodium-oxygen battery as well as achieve a near-perfect battery recharge.

The researchers said that the same process could eventually be used for lithium-oxygen batteries, potentially resolving the cost and size constraints of the lithium-ion batteries currently used to power everything from cell phones to electric cars.

Lithium-oxygen reactions are too unstable to generate sufficiently long battery life, but the Waterloo scientists said they're investigating redox mediators in order to enable more efficient charging.

The research, published in the journal Nature Chemistry, could also offer additional applications for sodium-oxygen batteries, which hold less energy than their lithium counterparts but are cheap enough for large-scale storage.

“Our new understanding brings together a lot of different, disconnected bits of a puzzle that have allowed us to assemble the full picture,” Chemistry Professor Linda Nazar said. “These findings will change the way we think about non-aqueous metal-oxygen batteries.”