New Tech Prepares Energy Storage Companies For Sodium-Ion Batteries

A successful energy transition hinges on batteries capable of storing renewable energy for use when it can’t be generated. While lithium-ion technology is the current the gold standard for batteries, alternatives are needed. New technology promises to help energy storage operators evaluate the suitability of sodium-ion batteries and plan accordingly. 

“Sodium-ion batteries are a promising alternative to lithium-ion batteries, primarily because of the difference in raw materials,” said Alexander Karger, a battery and machine learning engineer at the battery analytics software company Twaice. “Sodium is available in significantly higher abundance than lithium. And sodium mining and refining are more environmentally sustainable, compared to lithium mining.”

Most of the materials used to create storage for renewable energy are not themselves renewable. Many of the extraction processes for lithium and cobalt — which is also needed for lithium-ion batteries — cause varying degrees of environmental and social harm, including environmental degradation, pollution and monopolization of water resources, displacement of Indigenous peoples, and widespread death and ecological destruction in the cobalt-rich Democratic Republic of the Congo.

On the other hand, sodium is plentiful in the natural environment and is considered a renewable resource. And sodium-ion batteries generally don’t require cobalt or other critical materials, Karger said. 

“There may be further advantages in terms of service life, costs, safety and performance,” he said. “However, the industry is still in the early stages of standardizing the materials required for sodium-ion, and we will have to wait before we can draw any concrete conclusions.”

This doesn’t mean sodium-ion batteries will eventually replace lithium-based batteries, especially where higher energy density is needed. By their very nature, sodium-ion batteries have a lower capacity for energy density, Karger said.

While that might make them less than ideal for long-range electric vehicles, they are effective for a variety of uses, including storing renewable energy at scale.

But energy storage operators need information about how these batteries age to plan their implementation and manage energy systems. Twaice already offers software that simulates the aging of lithium-ion batteries to help operators learn that information.

By further developing its simulation models to work with sodium-ion batteries, the company will help operators understand how they behave and age, too, Karger said. This is the first model of its kind to work with non-lithium batteries, and it will help determine the suitability of sodium-ion batteries for specific projects and optimize their use without oversizing their storage. 

“Our simulation models provide a fundamental understanding of sodium-ion battery aging under varying operating conditions,” Karger said. “So far, we are seeing that sodium-ion batteries degrade generally similar to lithium-ion batteries, and that we can transfer a lot of methods we use for lithium-ion battery modeling. Moreover, the cells we have tested show a promising lifetime, indicating a high potential of sodium-ion batteries to be deployed for different applications.”

There are, of course, limitations to the simulation. The information gleaned from the models is generally only valid for the conditions within the company’s Battery Research Center, where the testing takes place, Karger said. But Twaice uses its battery expertise, artificial intelligence, and machine learning to estimate how they will perform in other conditions as accurately as possible.

Integrating sodium-ion batteries into energy storage systems offers a better option for the environment and communities near mines. But such alternative options are also necessary to meet the exponential growth in demand for batteries caused by the energy transition. Reliable models for understanding how these batteries degrade and behave are integral to making that happen, and they will likely become more so with the standardization and increased use of sodium-ion.