A commercial sodium-ion battery from Chinese manufacturer Hina compares favorably to Tesla's lithium-ion cells in terms of build quality and internal design, according to an independent analysis published in the journal Cell Reports Physical Science.
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Researchers at RWTH Aachen University in Germany measured cell-to-cell resistance, which showed a variation of just 5.3% across 120 cells, indicating a tightly controlled mass production that rivals the best lithium cells on the market.
The study, led by Christian Siebert and Moritz Schütte, compared a widely used sodium-ion cell from Hina with Tesla's more advanced lithium-ion technology. The team used impedance spectroscopy on 120 cells to assess uniformity and tested performance at currents and temperatures ranging from −20°C to 45°C. They used X-rays to image the internal structure before physically disassembling the cells to measure the dimensions, composition, and microstructure of the electrodes.
The surprising finding was structural. Hina's cell uses a "tabless dual aluminum current collector design that reduces resistance and ensures uniform temperature distribution," mirroring Tesla's current battery design. This tabless architecture is the same feature Tesla introduced with the 4680 cell, and the researchers noted that this is the first commercially available sodium-ion battery to use it.
Sodium ions have a structural cost advantage as they can use aluminum current collectors on both sides of the cell, while lithium ions require more expensive copper on the anode side.
The researchers acknowledged that the cell still lags behind the leading lithium-ion technology in two areas. The first is energy density. Today's commercial sodium-ion cells generally have lower energy densities than the best lithium-ion cells, making sodium more suitable for static storage, grid services, and shorter-range or commercial vehicles than for long-range passenger EVs.
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The second issue is cold weather charging. While sodium handles discharge well at low temperatures, charging remains problematic. For applications that require frequent charging at low ambient temperatures, appropriate thermal management or operating strategies will be important, as charging at low temperatures is a distinct weakness.
The analysis also revealed an unexpectedly high and unevenly distributed presence of copper in parts of the cathode, raising questions about its role in performance and aging. Schütte expressed a desire to see future sodium cells “free of nickel and copper” while achieving competitive energy density.
This finding comes as Chinese battery giants are pushing sodium-ion technology from laboratory curiosity to mass production. CATL is launching its Naxtra sodium-ion batteries in EVs in 2026, targeting around 175 Wh/kg and around 600 km (372 miles) of range as the chemistry matures, with charging capabilities down to −30°C.
The technology is already in use. In February, CATL and Changan unveiled the world’s first mass-produced sodium-ion EV, the Changan Nevo A06. Researchers are also addressing sodium’s shortcomings, with one team demonstrating a sodium-ion cell with an 11-minute charge and a range of 450 km.
Hina, a subsidiary of the Chinese Academy of Sciences, supplies cells for both vehicles and grid storage and has demonstrated commercial packages with an efficiency of around 165 Wh/kg.
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While the headline suggests that a Chinese sodium-ion battery “compares” to Tesla, it’s important to clarify that sodium still lags behind lithium in energy density, the key measure for EV range.
