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While lithium-ion battery prices are falling again, interest in sodium ion (Na-ion) energy storage has not waned. Although there is a global increase in cell manufacturing capacity, it is not yet clear whether this promising technology can tip the balance of supply and demand.
Sodium ion batteries are going through a critical marketing period, since sectors such as automotive and energy storage are betting heavily on this technology. Established battery makers and newcomers are competing to move from the lab to the factory floor with a viable alternative to lithium-ion. With the latter as the standard for electric mobility and stationary storage, the new technology should offer proven advantages. Sodium ion appears well placed, with superior safety, raw material costs and environmental credentials.
Sodium ion devices do not require critical materials, using abundant sodium instead of lithium, and do not require cobalt or nickel. When lithium-ion prices rose in 2022, amid predictions of materials shortages, sodium-ion emerged as a rival and interest remains strong even as lithium-ion prices have begun to fall again. .
“We are currently tracking 335.4 GWh of sodium ion cell production capacity through 2030, highlighting that there remains significant commitment to this technology,” said Evan Hartley, principal analyst at Benchmark Mineral Intelligence.
In May 2023, the London consultancy had calculated 150 GWh until 2030.
Cheaper
Sodium ion cells, produced at scale, could be 20% to 30% cheaper than lithium ferro/iron phosphate (LFP), the dominant stationary storage battery technology, thanks mainly to abundance of sodium and low extraction and purification costs. Sodium-ion batteries can use aluminum for the current-collecting anode instead of copper used in lithium-ion batteries, further reducing costs and supply chain risks. However, those savings are still potential.
“Before sodium-ion batteries can compete with current lead-acid and lithium iron phosphate batteries, industry players will have to reduce the cost of the technology by improving technical performance, establishing supply chains and achieving economies of scale,” says Shazan Siddiqi, technology analyst at UK-based market research firm IDTechEx. “The cost advantage of Na-ion will only be achieved when the production scale reaches a manufacturing level comparable to that of lithium-ion cells. Furthermore, a further drop in the price of lithium carbonate could reduce the price advantage offered by sodium.”
Sodium ion is unlikely to supplant lithium ion in applications that prioritize high performance, and will instead be used for stationary storage and electric microvehicles. S&P Global analysts predict lithium-ion will supply 80% of the battery market in 2030, with 90% of those devices based on LFP. The sodium ion could represent 10% of the market.
Suitable options
Researchers have been studying the sodium ion since the mid-20th century, and recent advances include improvements in the storage capacity and life cycle of devices, as well as new materials for anodes and cathodes. Sodium ions are bulkier than their lithium counterparts, so sodium ion batteries have lower voltage and lower gravimetric and volumetric energy density.
The gravimetric energy density of sodium ions is currently between 130 Wh/kg and 160 Wh/kg, but is expected to exceed 200 Wh/kg in the future, above the theoretical limit of LFP devices. In terms of power density, however, sodium-ion batteries could be 1 kW/kg, above the 340 W/kg to 420 W/kg of nickel-manganese-cobalt (NMC) and 175 W/kg to 425 W/kg for LFP.
While the lifespan of sodium ion devices, 100 to 1,000 cycles, is lower than that of LFP, Indian developer KPIT has reported a lifespan of 80% capacity retention for 6,000 cycles. -depending on the cell chemistry-, comparable to that of lithium-ion devices.
Siddiqi of IDTechEx says: “There is still no single winning chemistry within sodium-ion batteries. “There are a lot of R&D efforts going on to find the perfect anode/cathode active material that allows scalability beyond the laboratory phase.”
Referring to US-based safety science organization Underwriter Laboratories, Siddiqi added that “UL standardization for sodium ion cells is therefore still some way off and this makes OEMs [original equipment manufacturers] hesitant.” when it comes to committing to this technology.”
Prussian white, polyanion, and stratified oxide are cathode candidates with cheaper materials than their lithium-ion counterparts. The first, used by Northvolt and CATL, is widely available and cheap, but has a relatively low volumetric energy density. The British company Faradion uses stratified oxide, which promises higher energy density, but its capacity reduces over time. The French Tiamat uses polyanion, more stable but with toxic vanadium.
“Most sodium-ion battery manufacturers will use stratified oxide cathode technology,” says Benchmarks Hartly. “In fact, 71% of [battery] projects are stratified oxide. Similarly, 90.8% of sodium ion cathodes are stratified oxide.”
While the cathodes are the main cost factor for lithium-ion batteries, the anode is the most expensive component of sodium-ion batteries. Hard carbon is the standard choice for sodium ion anodes, but production capacity lags behind that of sodium ion cells, driving up prices. Recently, hard carbon materials have been obtained from various precursors, such as animal waste, sewage sludge, glucose, cellulose, wood, coal and petroleum derivatives. Synthetic graphite, the common material for lithium-ion anodes, depends almost exclusively on the last two precursors. With its developing supply chain, hard carbon is more expensive than graphite and represents one of the main obstacles in the production of sodium ion cells.
To partially mitigate higher costs, sodium-ion batteries have better temperature tolerance, especially in sub-zero conditions. They are safer than lithium-ion as they can be discharged to zero volts, reducing risk during transport and disposal. Lithium-ion batteries are typically stored at 30% charge. Sodium ion ones have less risk of fire, since their electrolytes have a higher flash point, that is, the minimum temperature at which a chemical substance can vaporize and form a flammable mixture with air. Since both chemicals have a similar structure and operating principles, sodium ion can often be integrated into lithium ion production lines and equipment.
In fact, the worlds leading battery manufacturer, CATL, is integrating sodium ion into its lithium ion infrastructure and products. Its first sodium ion battery, launched in 2021, had an energy density of 160 Wh/kg, with a promise of 200 Wh/kg in the future. In 2023, CATL said Chinese automaker Chery would be the first to use its sodium-ion batteries. At the end of 2023, CATL told pv magazine that it had developed a basic industrial chain for sodium-ion batteries and established mass production. The scale of production and shipments will depend on the execution of customers projects, CATL said, adding that much remains to be done for large-scale commercial deployment of sodium ion. “We hope that the entire industry will collaborate to promote the development of sodium ion batteries,” says the manufacturer.
On the load with sodium
In January 2024, BYD, Chinas largest automaker and second-largest battery supplier, announced that it had started construction of a CNY 10 billion ($1.4 billion), 30 GWh sodium-ion battery factory by anus. Its production will power “micromobility” devices. HiNa, a subsidiary of the Chinese Academy of Sciences, launched a one-gigawatt-hour sodium-ion battery production line in December 2022 and announced a range of sodium-ion batteries and an electric car prototype.
European battery manufacturer Northvolt introduced 160 Wh/kg sodium ion battery cells in November 2023. This technology, developed in collaboration with Altris, a subsidiary of Uppsala University, Sweden, will be used in the companys next generation of energy storage devices. Northvolts current offering is based on NMC chemistry. In the presentation, Wilhelm Löwenhielm, senior business development manager for energy storage systems at Northvolt, said the company wants a battery that is competitive with large-scale LFP. “Over time, the technology is expected to significantly outperform LFP in terms of cost competitiveness,” he said.
Northvolt wants a “plug-and-play” battery to quickly enter the market and expand it. “The key activities to bring this technology to the market are the expansion of the supply chain for battery materials, which Northvolt is currently carrying out together with its partners,” explains Löwenhielm.
Other smaller companies are also doing their bit to commercialize sodium ion technology. Faradion, which was acquired by Indian conglomerate Reliance Industries in 2021, says it is now moving its next-generation cell design into production. “We have developed a new cell technology with 20% greater energy density and a third longer life than our previous design,” said James Quinn, CEO of Faradion.
The companys first-generation cells demonstrated an energy density of 160 Wh/kg. In 2022, Quinn said Reliances plan was to build a double-digit gigawatt sodium ion factory in India. For now, it appears those plans remain on track. In August 2023, Reliance Chairman Mukesh Ambani stated at the companys annual shareholder meeting that the business is “focused on accelerated commercialization of our sodium-ion battery technology… We will build on our technological leadership to industrialize sodium ion cell production to megawatt level in 2025 and rapidly scale up to gigawatts thereafter,” he said.
Production
The startup Tiamat has advanced its plans to begin construction of a 5 GWh production plant in the French region of Hauts-de-France. In January 2024, it raised €30 million ($32.4 million) in equity and debt financing and said it expects to complete financing for its industrial project in the coming months, bringing total financing to around $150 million. of euros. The company, a spin-off of the French National Center for Scientific Research, will initially manufacture sodium ion cells for power tools and stationary storage applications in its factory, “to meet the first orders that have already been received.” Going forward, it will aim to increase production of second-generation products for electric vehicle applications.
In the United States, companies in the sector are also intensifying their marketing efforts. In January, Acculon Energy announced mass production of its sodium-ion battery packs and modules for mobile and stationary energy storage applications, and unveiled plans to expand production to 2 GWh by mid-2024. Natron Energy, a spin-off company from Stanford University, planned to begin mass production of its sodium-ion batteries in 2023. Its goal was to manufacture 600 MW of sodium-ion cells at the Meadowbrook lithium-ion facility, in Michigan. However, updates on progress have been limited.
Financing
In October 2023, Peak Energy emerged with $10 million in funding and a management team made up of former Northvolt, Enovix, Tesla, and SunPower executives. The company said it would initially import battery cells and that that was not expected to change until early 2028. “You need about $1 billion for a small-scale gigawatt factory — less than 10 GW,” said Landon Mossburg, a senior adviser. Peak Energy delegate, in the presentation. “So the quickest way to get to market is to build a system with cells available from a third party, and China is the only place that is building capacity to ship enough cells.” Over time, the company hopes to qualify for domestic content credits under the U.S. Inflation Reduction Act.
Some suppliers, such as Indias KPIT, have entered this sector without production plans. This automotive software and engineering solutions company introduced its sodium-ion battery technology in December 2023 and embarked on a search for manufacturing partners. Ravi Pandit, president of KPIT, said the company has developed multiple variants with energy density ranging between 100 Wh/kg and 170 Wh/kg, and could go up to 220 Wh/kg.
“When we started working on sodium-ion batteries, the initial expectations for energy density were quite low,” he said. “But in the last eight years energy density has been increasing thanks to the developments that we and other companies have carried out.” Others are on the lookout for supply associations. Last year, Finnish technology group Wärtsilä – one of the worlds leading integrators of battery energy storage systems – said it was looking at possible partnerships or acquisitions in the field. At the time, it was testing the technology at its research facility. “Our team remains committed to pursuing new opportunities in terms of diversifying energy storage technologies, such as incorporating sodium ion batteries into our future stationary energy storage solutions,” said Amy Liu, chief development officer. of strategic solutions from Wärtsilä Energy Storage and Optimization, in February 2024.
Nearshoring opportunity
After many mass production announcements, sodium-ion batteries are now at the tipping point and investor interest will determine the fate of the technology. IDTechEx market analysis, conducted in November 2023, suggests projected growth of at least 40 GWh by 2030, with an additional 100 GWh of manufacturing capacity depending on market success by 2025.
“These projections assume an imminent boom in the [sodium ion battery] sector, which depends on commercial commitment in the coming years,” says Siddiqi.
Sodium ion could offer another opportunity to near-shore clean energy supply chains, with the necessary raw materials so readily available around the world. However, it seems that the train has already left the station.
“As in the early stages of the lithium-ion battery market, the main obstacle to the global industry will be Chinas dominance,” says Benchmarks Hartley. “In 2023, 99.4% of sodium ion cell capacity was based in China, and this figure is only expected to drop to 90.6% in 2030. Just like politics in Europe and South America North seeks to shift lithium-ion battery supply chains away from China, due to reliance on its domestic production, a shift in the sodium-ion market will also be necessary to create localized supply chains.” |
