Northvolt announced the successful development of in-house Na-ion battery technology with an energy density of >160Wh/kg.

Northvolt's recent focus has been on Li-ion and the company is one of a number of players looking to set up in a Western jurisdiction via its proposed battery manufacturing facility in Sweden. The company, backed by Glencore, BlackRock and VW, is targeting not only Li-ion cells but also other battery chemistries. Last week, Northvolt announced that it had developed a sodium-ion (Na-ion) battery at its R&D lab in Sweden, with its partner Altris, that has been validated with an energy density of >160Wh/kg. 

Northvolt’s Na-ion battery puts them on par with companies such as CATL, which announced its first-generation 160Wh/kg Na-ion battery in 2021. However, it is lagging behind the likes of CATL in terms of production plans, aiming to achieve mass production by 2030, while Chinese manufacturers are already at the threshold of mass-producing Na-ion batteries.

CATL and Funeng Technology have both announced the launch of their Na-ion batteries in electric vehicles. Meanwhile, BYD has announced a joint venture investment into building a Na-ion battery project with an annual production capacity of 30GWh, and Zhong Na Energy's 20GWh polyanionic Na-ion battery factory recently held a ground-breaking ceremony.

Na-ion batteries have several desirable characteristics compared to Li-ion technologies. Despite being heavier per kWh of storage capacity, Na-ion chemistries contain different, lower-value materials than Li-ion and can, therefore, be lower cost. The specifics of the chemistries depend on the type of Na-ion technology; Prussian white, layered oxide or polyanion are the three key varieties. As these don't need lithium, cobalt, and nickel (some chemistries will use small amounts) they could be produced without much exposure to Li-ion metals which have seen high and volatile prices in recent years.

And it's not just about the cost - the technology shows performance promise too. Na-ion technology is catching up with LFP in terms of cell-specific energy (Wh/kg), but its cell energy density (Wh/L) is still roughly two-thirds of that achieved by LFP. Meanwhile, while nickel-based chemistries remain far superior in terms of storing energy they lack the cycle life of LFP and Na-ion technologies.  

Project Blue’s base case anticipates that Na-ion will provide a compelling alternative for low-range EVs and energy storage applications, using sodium electrolyte and hard carbon anode (containing none of the five battery materials associated with traditional Li-ion chemistries). Most potential producers seem to be targeting layered oxide cathode technologies, though the development of other cathode designs is being undertaken by several other companies globally. However, we also believe much will depend on the extent to which Na-ion can provide a low-cost alternative to Li-ion, which itself is highly dependent on future lithium prices.