When It Comes to Battery Performance, Sodium May Just Be the New Lithium

Watch out lithium-ion batteries! There is new material in town, and it may just make sodium-ion batteries more efficient than lithium-ion ones, particularly in speed of charge.

The new material was discovered and demonstrated by researchers at the Nagoya Institute of Technology (NITech) in Japan.

Competing with lithium-ion

Lithium-ion batteries are near ubiquitous and with good reason. They are highly efficient. However, lithium is a very limited and costly resource and has sometimes even been labeled as the reason electric car adoption has not happened faster.

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Sodium-ion could soon become an alternative that will be both cheaper and more accessible. Not only is sodium abundant on Earth but sodium-based components have an ideal crystal structure design that could yield much faster charging times.

There is one complication, however. Sodium is a larger size than lithium and has different chemistry. This makes it impossible to simple swap lithium with sodium.

Researchers have been on the hunt for a solution to this problem, and this new team may just have found it. But it was no easy feat.

Scientists at NITech extracted about 4300 compounds from a crystal structure database and proceeded to conduct a high-throughput computation. Only one of the compounds proved efficient, and that is  Na2V3O7.

A 6 minute charging time

Na2V3O7 had both the right electrochemical performance as well as crystal and electronic structures. The compound even yielded an impressive charging time, within 6 minutes, and indicated the potential for a long battery life.

"Our aim was to tackle the biggest hurdle that large-scale batteries face in applications such as electric cars that heavily rely on long charge durations. We approached the issue via a search that would yield materials efficient enough to increase a battery's rate performance".

Before you get too excited it should be noted that Na2V3O7 was found to, unfortunately, deteriorate in the final charging stages. The researchers estimate that this would limit the practical storage capacity to half of the theoretical one.

However, all is not lost. The researchers are hard at work looking to improving Na2V3O7's performance to eliminate this glitch and hopefully produce a compound that is stable throughout the entire duration of the charging stages.

"Our ultimate goal is to establish a method that will enable us to efficiently design battery materials via a combination of computational and experimental methods," Dr. Tanibata added.

The study is published in the journal Scientific Reports.