A new study shows that a commercial sodium-ion battery produced by a Chinese company can compete with Tesla's lithium-ion battery in terms of manufacturing consistency and multiple key performance indicators, opening up prospects for this low-cost new battery technology to accelerate its application in electric vehicles and grid energy storage. The research team pointed out that if further breakthroughs can be made in low-temperature charging capabilities and energy density, sodium-ion batteries are expected to become a more cost-effective alternative in electric vehicles and large-scale energy storage systems.
The study, published in Cell Reports Physical Science, a journal of Cell Press, is based on a commercial sodium-ion battery that has been used in passenger cars and large-scale energy storage projects in China. The results show that this battery launched by the Chinese company Hina is close to the level of lithium-ion batteries currently used by Tesla in terms of manufacturing process uniformity and overall performance. The researchers believe the discovery means the industrialization of sodium-ion technology will be faster than many in the industry previously expected.
Moritz Schütte, a battery researcher from RWTH Aachen University in Germany, said that the consistency, high-rate performance and low-temperature performance of this batch of cells make them attractive for stationary energy storage, grid auxiliary services, and short-distance or commercial vehicles that are relatively insensitive to endurance requirements, but are more concerned with cost and resource supply. At the material level, sodium-ion technology uses sodium instead of lithium as the core current-carrying ion. With the help of sodium, a widely existing and more abundant element, it is expected to significantly reduce the cost of battery raw materials and alleviate long-term supply chain risks.
In order to evaluate the gap between this Zhongke Hainan sodium-ion battery and Tesla's advanced lithium battery, the research team conducted a systematic test on 120 cells and used non-destructive testing methods such as electrochemical impedance spectroscopy to evaluate their manufacturing consistency. The team then tested the power and energy output of the battery cells at different charging rates and temperatures ranging from −20°C to 45°C under conditions that simulated real-life usage. Through X-ray imaging and disassembly analysis, the researchers also carefully characterized the battery's internal structure, pole piece size, material composition, and microscopic features.
The analysis results show that the structural design of the sodium-ion battery is quite mature, using designs such as electrodeless ears and double aluminum current collectors to reduce internal resistance and improve the uniformity of temperature distribution. Its overall layout is highly similar to the current Tesla battery architecture. Schütte bluntly stated that the team was "pleasantly surprised" by the consistency of this batch of cells, believing that their manufacturing level has far exceeded the traditional impression of "the first commercial sodium-ion products." At high rates, the sodium-ion battery's output capabilities are also better than researchers typically expected for early commercial products.
Despite its impressive performance, research also points out that the sodium-ion battery still has key shortcomings compared with top-notch lithium-ion batteries. In terms of low-temperature charging, battery performance is still insufficient. Applications that frequently charge under low ambient temperature conditions require more sophisticated thermal management strategies and operation plans. The research team also detected abnormally high and unevenly distributed copper content in local areas of the cathode, which raised further questions about its role in long-term performance and aging behavior.
At present, commercial sodium-ion batteries still lag behind the most advanced lithium-ion products in terms of energy density, and the maturity of related technologies is also relatively low. However, research shows that this type of battery can still maintain good output performance in low temperature and high load environments, giving it potential advantages in stationary energy storage and vehicle applications operating in cold areas. Schütte said that in the future, the attractiveness of sodium-ion technology will be further enhanced if it can maintain competitive energy density while getting rid of dependence on metals such as nickel and copper.
In the next step, the research team plans to focus on improving the charging behavior of sodium-ion batteries in environments below 0°C to achieve safer and more efficient charging under severe cold conditions. In terms of material systems, improving hard carbon anode and electrolyte formulas is considered one of the most promising directions. Relevant research has been funded by the German Federal Ministry of Research, Technology and Space and the Federal Ministry of Economics and Energy, showing that European scientific research and government departments are paying close attention to the potential of sodium ion routes in the next-generation battery technology landscape.