Sodium-ion batteries’ three big promises – IDTechEx

Sodium-ion batteries are emerging as a compelling alternative to lithium-ion, offering a unique blend of material abundance, system compatibility, and enhanced safety.

So says IDTechEx principal technology analyst Shazan Siddiqi, adding that as the energy storage market searches for scalable, cost-effective solutions, sodium-ion’s core promises could reshape how and where batteries are deployed.

Advantages include mineral abundance.

Lithium prices spiked to over US$80,000 per ton in 2022 due to geopolitical tension, post-COVID supply issues, and rising demand, says Siddiqi.

“This highlighted the fragility of a supply chain dominated by China, which controls over 93% of graphite processing and more than 80% of global gigafactory output.

“While lithium prices have since dropped to around US$10,000 per ton, sodium carbonate remains far cheaper. This implies a lower bill of materials and reduced exposure to supply shocks. Sodium is also widely available and can be sourced from common materials like trona or salt, making it a strong candidate for domestic production.”

IDTechEx’s report Sodium-ion Batteries 2025-2035: Technology, Players, Markets, and Forecasts says if lithium prices climb above US$50,000 per ton again then sodium ion’s cost advantage will become even more pronounced.

Sodium ion batteries offer strong compatibility with existing lithium-ion manufacturing and can often be made using the same formats and equipment, enabling faster and cheaper scale-up, says Siddiqi.

“However, compatibility depends on the chemistry,” he says.

“Some materials, like layered oxides and Prussian Blue analogues, are moisture sensitive and require dry room handling to avoid performance loss from reactions with water vapour.

“Sodium ion cells also have lower energy density, meaning more cells are needed to store the same energy. This increases equipment needs and raises processing costs by an estimated 15%. Still, sodium ion can leverage much of the lithium-ion supply chain, with shared processes and infrastructure offering a valuable shortcut to industrial scale.”

Safety benefits include shipping sodium ion batteries at zero state of charge, unlike lithium-ion cells.

“This reduces the risk of fire during transport and makes shipping safer, easier, and cheaper,” says Siddiqi.

“It is a key logistical advantage, especially for global supply chains.”

Siddiqi says sodium ion batteries typically use hard carbon anodes.

“Because sodium does not intercalate into graphite, this enables the use of different electrolyte solvents like propylene carbonate, or PC, which has a high flash point and wide liquid range. It is generally unsafe in lithium-ion systems but works well in sodium ion cells. PC can replace more flammable solvents like DEC and DMC, improving thermal stability and safety.”

Safety depends heavily on the specific chemistry used, says Siddiqi.

“For example, layered oxide materials like NFPP or NFM behave differently under abuse conditions. These differences are covered in more detail in the full IDTechEx report, which includes ARC test data from several sodium ion battery developers.

“In thermal abuse scenarios, sodium ion cells tend to enter thermal runaway at higher temperatures and progress more slowly than lithium-ion cells, which offers added safety under certain conditions.”

Sodium ion cells could reach a competitive price point, not necessarily cheaper than LFP, but close enough that system-level improvements such as reduced operations and maintenance costs could tip the balance, like how LFP gained traction through cell-to-pack innovations, says Siddiqi.