One of the next-generation secondary batteries, sodium (sodium) ion batteries are emerging as a strong alternative to lithium-ion batteries. Following the supply chain instability caused by the COVID-19 pandemic in 2022 and the soaring prices of lithium, expectations for sodium ion batteries are also increasing.
However, an analysis has concluded that, with current technology, sodium ion batteries struggle to substitute for lithium ion batteries. The project research team "STEER," including Stanford University in the United States, released the analysis that for sodium ion batteries to secure competitiveness against lithium ion batteries, several technological innovations and market conditions must be supported rather than merely expanding production scale. The research findings were published in the international journal "Nature Energy" on the 13th.
Sodium ion batteries can secure resources more stably than lithium ion batteries and are likely to be more advantageous in terms of expense. Sodium has over 1000 times the reserves of lithium and is relatively easy to mine and refine. Additionally, sodium has lower reactivity than lithium, resulting in higher electrochemical stability within the battery, and it maintains performance well even at low temperatures. However, sodium ion batteries have lower energy density than lithium ion batteries, shorter lifespans, and a complicated manufacturing process, which has restricted their commercialization.
The research team examined the economic feasibility of more than 6,000 scenarios for the commercialization of sodium ion batteries. They also considered ways to secure price competitiveness compared to lithium ion batteries. The research team noted, "Many battery corporations have announced plans to expand production of sodium ion batteries to lower prices, but it is difficult to replace lithium ion batteries merely by increasing production scale."
Instead, they emphasized the need for research to increase energy density and optimize key materials in the design of sodium ion batteries. The research team commented, "The most important thing is to reduce dependency on expensive metals like nickel while increasing energy density," adding, "To compete with the low-cost form of lithium iron phosphate (LFP) lithium ion batteries, it is essential to achieve energy density similar to that of lithium iron phosphate while lowering prices."
The research team predicted that market changes could enhance the price competitiveness of sodium ion batteries. For example, if China restricts the export of graphite, a key raw material used in lithium ion batteries, the market competitiveness of sodium ion batteries could significantly increase. China accounts for over 90% of the global graphite supply. As early as December 3rd of last year, China began to limit graphite exports to the United States and simultaneously banned exports of minerals including gallium, germanium, and antimony.
William Chueh, director of the Precourt Institute for Energy, who led the research, said, "We need to look at not only battery prices but also the potential for success across the entire system," and added, "Additional factors such as safety expenses in electric vehicles or large-scale energy storage systems are also crucial elements for securing competitiveness."
Reference materials
Nature Energy (2025), DOI: https://doi.org/10.1038/s41560-024-01701-9