Is Sodium-Ion the Future of EV Batteries?

Sodium-ion batteries are burgeoning as a popular alternative to lithium-ion batteries, thanks to the efforts of Chinese automakers who are pushing for its mainstream adoption.

Leading Chinese companies like CATL and BYD are ramping up the production of sodium-ion batteries. In mid-April, CATL and Chery unveiled their new battery brand, “ENER-Q”, which includes full product lines including sodium-ion, iron phosphate lithium, and ternary lithium batteries. Chery’s new energy vehicles will be the first to use CATL’s sodium-ion batteries.

Following CATL, BYD is rumored to start mass production of its sodium-ion batteries in the second half of this year, which will be used in its compact hatchback, the Seagull series. Both the moves have once again sparked discussions about battery technology in the market.

Geopolitical risks fuels Sodium-ion Batteries

Considering market supply and technical stability, lithium-ion batteries and iron phosphate lithium batteries are still the most popular types of batteries for electric vehicles. The former has a higher energy density but contains cobalt and nickel, which drives up costs. The latter has a lower cost but a lower energy density.

Sodium-ion batteries, on the other hand, have been overlooked due to their low energy density compared to traditional lithium-ion batteries.

So, why are companies like CATL and BYD turning to sodium-ion batteries?

Geopolitical risk is a major factor. Most lithium mines are located in countries like the US, Australia, and Canada. In today’s anti-China political climate, these materials could be used as bargaining chips to curb China’s electric vehicle industry. China won’t want to be at the mercy of other countries when it comes to the fate of its EV industry, so developing new technological routes is crucial.

From a mass production perspective, sodium is a more abundant element in the Earth’s crust than nickel, cobalt, or lithium carbonate, with a distribution that’s more evenly spread out. As such, sodium could be a better fit as a positive electrode material in batteries in the long run. Industry experts predict that sodium-ion batteries could even cost 20% less than iron phosphate lithium batteries once it reaches economies of scale.

The Supporting Actor in EV Batteries

However, a closer look into the pros and cons of both the materials may reveal that it’s not a zero-sum game. Instead, their characteristics can complement each other and help to accelerate battery technology development.

CATL’s new sodium-ion battery has an energy density of up to 160Wh/kg, which is comparable to the iron phosphate lithium battery in its Kirin battery system, but still lags behind the 255Wh/kg of ternary lithium batteries.

As a result, CATL is mixing sodium-ion and ternary lithium batteries in Chery’s new energy vehicles to balance cost and performance.

BYD is also expected to use a mix of sodium-ion and iron phosphate lithium batteries. Assuming this is true, it will echo the market’s assumption that sodium-ion batteries are not overturning the battery industry, but rather helping battery manufacturers maintain flexible product portfolios that cater to different market segmentations.

To give an example, CATL’s lithium iron phosphate batteries have been utilized in heavy-duty vehicles like 120-ton ore trucks and marine service vessels since 2022, where charging efficiency and cost take precedence over high energy density.

Therefore, sodium-ion batteries are likely to become a complimentary choice for lithium iron phosphate batteries, as they offer advantages such as high-rate charging, low cost, and high safety. This will definitely give car makers more flexibility in their future product strategies.