Experts found that heme, a molecule found in blood, can improve the efficiency of lithium-oxygen batteries.

Scientists continue to overcome obstacles
holding back the longer-lasting lithium-oxygen batteries, which may cause standard
lithium-ion batteries to be on the way out. The primary issue behind
lithium-oxygen batteries is the build-up of lithium peroxide, which reduces the
electrodes’ effectiveness, causing a lack in
efficiency.

yale-heme-battery-1

But now, a team at Yale tested a molecule
they discovered in blood that not only improves the lithium-oxygen function but also helps reduce biowaste. The
batteries have the potential to hold a charge for much longer than traditional
lithium-ion batteries, as well as the ability to extend the life of devices
such as smartphones to several weeks before they require a recharge. Before lithium-oxygen
batteries can be widely implemented, the
issues surrounding efficiency and lithium peroxide build-up need to be solved.

Prior studies have tried to reduce lithium
peroxide by keeping oxygen in the cell as a
solid and by modifying the electrode to produce
superoxide instead. Using this, the Yale researchers looked for a new
catalyst that lets lithium oxide in the cell decompose back into lithium ions
and gaseous oxygen. They found the answer in a very unexpected place: animal
blood.

The blood transports oxygen around the body
thanks to a protein called hemoglobin. 
The heme molecule makes up a portion of that protein and researchers
found when used in the battery, it dissolves into the electrolytes. This helped reduce the amount of energy needed
for the battery to charge and discharge.

Heme is often a disposed of waste product, so
the new application for the molecule could also help reduce the environmental
impact of other industries.

“We’re using a biomolecule that
traditionally is just wasted,” said Andre
Taylor, one of the study’s authors. “In the animal products industry, they
have to figure out some way to dispose of the blood. Here, we can take the heme
molecules from these waste products and use it for renewable energy
storage.”

The comprehensive
research can be found here.

Source: New Atlas