Sodium Batteries: A Low-Cost Alternative to Lithium

A new scientific study reveals that sodium-ion batteries are becoming a strong competitor to the lithium-ion batteries used by companies like Tesla. Researchers found that sodium batteries, which are already being used in electric cars and large energy storage systems in China, match many of the performance standards of their more expensive counterparts. These batteries are made from sodium, an element that is far more common in the Earth’s crust than lithium. This abundance could lower costs for manufacturers and reduce the risks associated with finding rare minerals.

The research was conducted by experts at a university in Germany. Their findings were published on May 28 in the journal Physical Science, which is part of Cell Press. The study focused on a specific battery designed by HiNa. HiNa is a company spun off from the Chinese Academy of Sciences. It has formed partnerships with major automakers, such as JAC, to supply batteries for electric vehicles. The study aimed to see how this new technology compares to the advanced batteries currently leading the market.

The data suggests that with some improvements, sodium-ion batteries could become a cost-effective choice for future electric vehicles. The researchers noted that once the technology is tweaked to charge more effectively in cold weather and to hold more energy, it will be a viable alternative. Moritz Schütte, a battery researcher at RWTH Aachen University in Germany, highlighted the strengths of these cells. He explained that their good uniformity, high power capability, and strong performance in low temperatures make them attractive. These features are especially important for stationary energy storage, grid services, and shorter-range commercial vehicles where lower cost and resource availability matter more than maximum driving range.

To assess how HiNa batteries compare to Tesla’s advanced lithium-ion models, Schütte’s team used a non-destructive testing method called impedance spectroscopy. This technique allowed them to measure the uniformity of 120 sodium-ion battery cells. Uniformity is crucial because it ensures that every cell in a battery pack performs similarly. Next, the team mapped out the power and energy performances of individual cells under real-world conditions. They tested the batteries at varying electrical currents and at temperatures ranging from −20 °C to 45 °C. This wide range simulates both freezing winters and hot summers.

They also used X-rays to examine the battery’s internal structure. To get even more detail, they opened up the cells to measure their electrode dimensions, compositions, and microstructures. These detailed physical inspections provided a complete picture of how the battery was built and how it functioned.