Blood Batteries

Engineers Use a Molecule in the Blood to Build Better Batteries

Lithium-oxygen batteries are very promising batteries, but there are many problems scientists must overcome to make them the industry standard over the now commonly used lithium-ion battery. They are very useful and can hold a charge for an impressive period of time, but they're inefficient at the same time.  The batteries produce lithium peroxide, which overtime hinders the performance.  The battery has a high charging potential, meaning that it has about a 70% efficiency rate (stores 30% less of the energy charged into the battery).  The solution to the problems of the lithium-oxygen battery may be in our blood.

Researchers have been looking for a catalyst that can decompose the build up of lithium peroxide and turn it back into lithium ions and oxygen. Scientists found a molecule found in hemoglobin, a part of the blood that carries oxygen through the body, known as heme. After testing, scientists proved that the introduction to heme into the lithium-oxygen battery "could reduce the energy required to boost the efficiency of the batteries' charge-discharge cycles."

"When you breathe in air, the heme molecule absorbs oxygen from the air to your lungs and when you exhale, it transports carbon dioxide back out, so it has a good binding with oxygen, and we saw this as a way to enhance these promising lithium-air batteries."

- Andre Taylor, associate professor of chemical and environmental engineering at Yale

The discovery of heme to be used in the battery solves a few problems.  The biggest problem it solves is that it will make lithium-oxygen batteries more efficient by reducing the build-up of lithium peroxide.  Typically, batteries used in phones, electric cars, and some other devices are lithium-ion batteries, but if heme solves the build-up problem, then lithium-oxygen batteries will be much more efficient and will be able to hold a charge for a very long amount of time.  Another minor problem it will solve is that if the batteries are commercialized, then animal products industries, who need to find ways to safely dispose of blood, can give/sell this unwanted blood to be turned into batteries. Engineers can use a biomolecule that it typically wasted and use it for renewable energy storage.

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