By Lucas Bettle

 

Lithium-ion batteries currently dominate the battery market, powering electric vehicles (EVs), providing large-scale stationary storage, and being used in a wide range of devices. However, they pose serious concerns related to resource scarcity, supply chain vulnerability, environmental impact, safety, and cold-weather performance. A variety of alternative battery chemistries are vying to enter the market, and sodium-ion batteries could be on the verge of breaking through.

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Recent Developments in Commercial Sodium-Ion Battery Production

 

Contemporary Amperex Technology Co. (CATL) is the world’s largest EV battery manufacturer. In September 2025, it reached a milestone by receiving certification under China’s Safety Requirements for Power Batteries Used in Electric Vehicles for its Naxtra sodium-ion EV battery. The company has plans to implement the batteries in full-scale new vehicle production in 2026 (Heynes, 2025).

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Energy density is the amount of energy a battery can store per unit weight, with higher energy density meaning more energy storage capacity and lower weights for EVs. Historically, poor energy density has made sodium-ion batteries unsuitable EVs.

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However, CATL now claims that its sodium-ion batteries achieve an energy density of 175 Wh/kg, comparable to lower-end lithium-ion batteries. The company also claims the batteries can reach 80% state of charge within 15 minutes at room temperature (Heynes, 2025).

Cold-weather performance has been a persistent concern for lithium-ion EV batteries, especially in northern climates such as Canada. CATL states that their new battery can achieve fast-charging performance across a window of –40°C to 70°C, with 90% usable capacity at –40°C (Guerra, 2025). Lithium-ion batteries perform significantly worse in low temperatures, with a capacity loss of 50% at –20°C (Nekahi, 2024).

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There have also been developments in stationary storage applications, where low energy density is less of a concern. Also in September 2025, Peak Energy deployed a 3.5 MWh sodium-ion battery energy storage system at the Solar Technology Acceleration Center in Colorado, marking the first grid-scale sodium-ion installation in the country. Unlike lithium-ion battery energy storage systems, sodium-ion installations can operate without the need for costly auxiliary cooling (Lewis, 2025).

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Sodium-Ion Battery Chemistries

 

Sodium-ion batteries operate on the same basic principles as lithium-ion batteries. Ions transfer between an anode and a cathode through an electrolyte, the difference being the use of sodium ions in place of lithium ions. Like lithium-ion, sodium-ion battery chemistries vary depending on the choice of cathode, anode, and electrolyte materials.

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Layered sodium transition metal oxides are among the most promising cathode materials, with high theoretical capacities thanks to their layered crystal structures (Gill, 2024). 

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However, they also pose challenges due to the occurrence of harmful phase transitions and volume changes during charge and discharge However, charge and discharge cycles can trigger phase transitions that alter the physical crystal structure of the cathode material, causing changes in volume and introducing defects. (Wu, 2024).

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Polyanionic compounds, such as phosphates, pyrophosphates, fluorosulfates, and sulfates, exhibit exceptional cycling performance and thermal stability; however, they have low conductivity and volumetric energy density (Wu, 2024). Prussian blue analogs (PBAs) possess open-framework tunnel structures that facilitate rapid sodium-ion diffusion and high stability, but are susceptible to heating conditions (Wu, 2024).

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There is similar diversity among anode materials. Sodium metal anodes deliver exceptionally high capacity but can suffer from severe dendrite formation, where non-uniform deposition of sodium ions leads to the growth of needle-like structures. These structures reduce battery capacity and can short-circuit the battery if they pierce the separator (Wu, 2024).

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Insertion-type materials serve as anodes by reversibly inserting ions into their crystal structure. Various carbon materials are abundant and low-cost, but have low operating voltage (Gill, 2024).

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Organic compounds, such as sodium terephthalate, polyaniline, polyimide, and quinones, show potential as anode materials due to their flexibility and high energy density by weight; however, challenges include low conductivity, solubility in electrolytes, and volumetric energy density (Gill, 2024).

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Reducing Reliance on Critical Minerals

 

The use of critical minerals is among the most prominent concerns regarding lithium-ion batteries, with significant demand for lithium, nickel, cobalt, manganese, and graphite. Lithium constitutes just 0.002% of the Earth’s crust, while sodium makes up 2.3% and is more evenly distributed globally (Nekahi, 2024).

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Sodium-ion batteries avoid the consumption of lithium, cobalt, and graphite, along with significantly reducing nickel (Degen, 2024). This reduces reliance on exports from countries where forced labour and supply chain vulnerability pose serious concerns, such as the Democratic Republic of Congo for cobalt and China for graphite. It also reduces vulnerability to volatile critical mineral prices. A 10% increase in critical mineral prices would result in a 3.2% rise in lithium-ion battery costs, but only a 0.8% rise in sodium-ion battery costs (Wood Mackenzie, 2023).

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Addressing Thermal Runaway Risks

 

Thermal runaway is a self-propagating and uncontrollable temperature increase that can lead to catastrophic battery failure, posing a significant safety concern for lithium-ion batteries. Sodium-ion batteries are still susceptible to thermal runaway due to their similar chemistry. The overall risk depends on the specific materials used, with flammable liquid solvent electrolytes contributing significantly (Boozula, 2025).

While thermal runaway remains a risk, sodium-ion batteries do show potential improvements over lithium-ion batteries. They have improved thermal stability, partially due to the larger ionic radius of sodium, and also reach lower maximum temperatures during a thermal runaway (Boozula, 2025).

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Competitiveness vs. Lithium-Ion Batteries

 

In 2022, the three primary types of EV lithium-ion battery technologies dominated the market, with just 2% of production being alternative chemistries. Nickel manganese cobalt (NMC) accounted for 60%, lithium iron phosphate (LFP) 30%, and nickel cobalt aluminum (NCA) 8% (Evro, 2024).

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Energy density is a crucial requirement for electric vehicles, as they must have sufficient capacity for practical travel. LFP, NCA, and NMC have capacities reaching up to 160, 300, and 350 Watt-hours per kilogram (Wh/kg), respectively. In 2024, average costs per kWh of capacity were $53, $95, $85, respectively (Bloomberg NEF, 2025).

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CATL claims to have achieved an energy density of 175 Wh/kg with its Naxtra sodium-ion batteries, surpassing LFP but significantly lower than NCA and NMC. Prior to recent advancements, commercial sodium-ion batteries had achieved densities of only 75 to 90 Wh/kg. In 2020, even experimental sodium-ion cells would only achieve a theoretical pack density of 150 Wh/kg (Abraham, 2020).

 

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In addition to achieving practical energy density, the Naxtra battery could also significantly reduce costs. While specific values are not available for commercial production costs for these new batteries, earlier 1st-generation sodium-ion batteries from CATL were estimated to cost 30% less than LFP (IEA, 2023).

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Sodium-Ion Batteries Are Rapidly Becoming a Viable Alternative to Lithium-Ion Batteries

 

While promising due to their reduced critical mineral demand, lower costs, cold-temperature performance, and increased safety, sodium-ion batteries have faced challenges in many applications due to their low energy density and manufacturing difficulties.

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Recent advancements demonstrate that these challenges may be a thing of the past, with practical use of sodium-ion batteries in both stationary storage and electric vehicles being realized in current projects. While energy density remains low compared to higher-end lithium-ion battery chemistries, all signs indicate that sodium-ion batteries are poised for widespread adoption across various applications.

 

References​

 

Abraham, K. M. (2020). How Comparable Are Sodium-Ion Batteries to Lithium-Ion Counterparts? ACS Energy Letters.

Bloomberg NEF. (2025). Electric Vehicle Outlook 2025. 

Boozula, A. (2025). Review of thermal runaway risks in Na-ion and Li-ion batteries: safety improvement suggestions for Na-ion batteries. Journal of Engineering and Applied Science.

Degen, F. (2024). Comparative life cycle assessment of lithium-ion, sodium-ion, and solid-state battery cells for electric vehicles. Journal of Industrial Ecology.

Evro, S. (2024). Navigating battery choices: A comparative study of lithium iron phosphate and nickel manganese cobalt battery technologies. Future Batteries.

Gill, S. (2024). Sodium ion batteries - a comprehensive review. Journal of Materials Nanoscience.

Guerra, M. (2025). 5 Key Takeaways From CATL’s Naxtra Sodium-Ion Battery Launch. Retrieved from Battery Technology: https://www.batterytechonline.com/materials/5-key-takeaways-from-catl-s-naxtra-sodium-ion-battery-launch

Heynes, G. (2025). CATL’s sodium-ion EV battery passes China’s new certification with 15-minute fast-charging capability. Retrieved from EV Infrastructure News: https://www.evinfrastructurenews.com/ev-technology/catl-s-sodium-ion-ev-battery-passes-china-s-new-certification-with-15-minute-fast-charging-capability

IEA. (2023). Global EV Outlook 2023. 

Lewis, M. (2025). The US’s first grid-scale sodium-ion battery is now online. Retrieved from electrek: https://electrek.co/2025/09/25/us-first-grid-scale-sodium-ion-battery-is-now-online/

Nekahi, A. (2024). Comparative Issues of Metal-Ion Batteries toward Sustainable Energy Storage: Lithium vs. Sodium batteries.

Wood Mackenzie. (2023). Sodium-ion batteries: disrupt and conquer? Retrieved from Wood Mackenzie: https://www.woodmac.com/news/opinion/sodium-ion-batteries-disrupt/

Wu, Y. (2024). Recent Progress in Sodium-Ion Batteries: Advanced Materials, Reaction Mechanisms and Energy Applications. Electrochemical Energy Reviews.