A widely used sodium-ion battery developed by Chinese manufacturer Hina has achieved performance and manufacturing quality levels comparable to Tesla’s lithium-ion batteries, in keeping with research published within the Cell Press journal Cell Reports Physical Science.
The findings suggest sodium-ion technology could develop into a lower-cost alternative for future electric vehicles and large-scale energy storage systems. To succeed in that goal, nonetheless, the battery will need further improvements in low-temperature charging and energy density. Unlike lithium, sodium is abundant and available, making it a pretty material for reducing battery costs and provide chain concerns.
“The mixture of excellent uniformity, high power capability, and robust low-temperature performance makes these cells attractive for stationary storage, grid services, and shorter-range or business vehicles where potential lower cost and resource availability matter greater than maximum driving range,” says Moritz Schütte, a battery researcher at RWTH Aachen University in Germany.
Comparing Sodium-Ion Batteries With Tesla Technology
To judge the Hina battery, Schütte and colleagues examined 120 sodium-ion cells using impedance spectroscopy, a non-destructive method that measures battery uniformity.
The researchers then tested the cells under a wide range of real-world operating conditions. Performance was measured across different current levels and temperatures starting from −20 °C to 45 °C. The team also used X-rays to look at the batteries internally before disassembling them to investigate electrode dimensions, material composition, and microscopic structural features.
One notable discovery was the battery’s tabless, double-aluminum current collector design. This configuration helps reduce electrical resistance and promotes more even temperature distribution throughout the cell. The researchers noted that this design closely resembles the architecture currently utilized in Tesla batteries.
“We were positively surprised by how uniform the cells are,” says Schütte.
Strengths and Remaining Challenges
Despite the encouraging results, the researchers identified several areas where the sodium-ion battery still trails leading lithium-ion technologies.
“The high-power performance was higher than one might expect from an early business sodium-ion product,” says Schütte. “Nevertheless, for applications that require frequent charging at low ambient temperatures, appropriate thermal management or operating strategies will likely be necessary because low-temperature charging stays a transparent weakness.”
The team also detected unexpectedly high concentrations of copper in certain regions of the battery’s cathode. As well as, the copper was unevenly distributed throughout those areas.
In response to Schütte, this finding “raises interesting questions on its role in performance and aging.”
“It should be exciting to see future sodium-ion technologies which might be freed from nickel and copper, as well, while achieving competitive energy density,” he said.
Why Sodium Could Matter for Future Batteries
Because sodium is much more abundant and widely available than lithium, manufacturers could potentially lower raw material costs while reducing long-term supply chain risks.
Sodium-ion batteries also maintain strong performance under load in cold conditions, making them attractive for stationary energy storage systems and mobile applications operating in colder climates.
“Nevertheless, today’s business sodium-ion cells generally have lower energy density than the very best lithium-ion cells, and the technology is less mature overall,” said Schütte.
Next Steps for Sodium-Ion Research
The researchers plan to give attention to improving charging performance at low temperatures, with the goal of enabling safer and more efficient charging below 0°C.
Additional work may even explore ways to optimize the materials utilized in sodium-ion batteries.
“Advances in hard-carbon anodes and electrolyte formulations could also be especially promising,” he said.
The study was supported by the Federal Ministry of Research, Technology, and Space and the Federal Ministry for Economic Affairs and Energy.