A new study suggests that sodium-ion batteries, a newer type of rechargeable battery, could one day become a cheaper alternative to the lithium-ion batteries used by Tesla and many other electric vehicle manufacturers.
Researchers from RWTH Aachen University in Germany examined a commercially available sodium-ion battery made by the Chinese company Hina.
Their findings, published in Cell Reports Physical Science, show that the battery already matches some important performance and manufacturing standards seen in Tesla’s lithium-ion batteries.
The discovery is significant because sodium is much more abundant and easier to obtain than lithium. If sodium-ion technology continues to improve, it could help reduce battery costs and lower the risk of future shortages in battery materials.
To evaluate the battery, the researchers tested 120 battery cells using a non-destructive technique called impedance spectroscopy.
This method allowed them to measure how consistent the cells were without taking them apart.
They also tested the batteries under different temperatures ranging from minus 20 degrees Celsius to 45 degrees Celsius and examined how well they performed under various power demands.
The team further investigated the batteries using X-ray imaging to study their internal structure. Afterward, they opened some cells to examine the materials and design of the electrodes.
One of the most surprising findings was the high level of manufacturing quality. According to lead researcher Moritz Schütte, the cells were remarkably uniform. Consistency is important because it helps batteries operate more reliably and last longer.
The researchers also found that the battery uses a modern “tabless” design with double aluminum current collectors. This approach reduces electrical resistance, improves temperature distribution, and resembles the design used in Tesla’s latest batteries.
While the results were encouraging, the study also identified several weaknesses. The sodium-ion batteries currently store less energy than the best lithium-ion batteries. This means electric vehicles using them would generally have a shorter driving range.
Charging performance in cold weather was another challenge. The batteries could still deliver power well at low temperatures, but charging them below freezing remained difficult. The researchers say that better thermal management systems or improved charging strategies will be needed before sodium-ion batteries become widely used in cold climates.
The team also discovered unexpectedly high levels of copper in some parts of the battery’s cathode material. The role of this copper is not yet fully understood, and researchers want to investigate whether it affects battery performance or lifespan.
Despite these limitations, the scientists believe sodium-ion batteries have strong potential. Their combination of good durability, strong power output, and lower material costs could make them attractive for large-scale energy storage systems, power grids, commercial vehicles, and shorter-range electric cars.
Future research will focus on improving charging performance at temperatures below zero degrees Celsius and developing better battery materials, including advanced hard-carbon anodes and improved electrolytes.
If these challenges can be solved, sodium-ion batteries may become an important competitor to lithium-ion technology in the years ahead.
