Researchers from the University of Cambridge and the University of Birmingham are closer to creating a sodium-ion-based rechargeable battery. Sodium-ion batteries could replace lithium-ion (li-ion) batteries which are currently used in electric vehicles, laptops, cell phones and more.
Lithium is expensive and uses limited natural resources. The method for gathering lithium also uses a lot of energy. These factors are why researchers are looking for a material that can replace lithium. Electric cars are a huge growing trend, adding strain to the li-ion supply chain.
The team found that sodium could be the answer. Sodium is a great option because it abundant, found in seawater and other parts of the Earth. It is also a cheap material. But sodium ions are larger than lithium ions, making it impossible to replace lithium with sodium in current li-ion battery models.
In order to combat the size problem, the team set out to find new materials to create the other battery components that fit sodium’s size. The new materials needed to match a li-ion battery’s speed, energy and power density.
The researchers ran the quantum mechanical models on supercomputers at the University of Birmingham to predict what will happen when the sodium ions are inserted into phosphorous. The results confirmed that, with the correct battery materials, sodium would be an adequate replacement for lithium in rechargeable batteries.
After the experiments and testing, the final composition of the sodium electrode had a final capacity charge that was seven times the charging ability of graphite electrodes at the same weight.
"This is a huge win for computational materials science. We predicted how phosphorus would behave as an electrode in 2016 and were now able, with Professor Grey's team to provide insights into the experiment and learn how to make our predictions better. It's amazing how powerful combined theory-experimental approaches are,” said Dr. Andrew Morris.
The paper on this technology was published in the Journal of American Chemical Society.