It's no secret that lithium-ion batteries are at the forefront of modern energy storage and a key driver of global electrification efforts. However, producing lithium-ion batteries at the scale needed to meet growing demand appears to be an almost impossible task. In recent years, lithium producers have warned that the world could soon face a lithium shortage, possibly as soon as 2025.
A big reason is that, in just a few decades, lithium has gone from a niche metal used in the ceramics and pharmaceutical industries to one of the most in-demand metals. Albemarle Co., one of the world's largest lithium mining companies and leading the renaissance of lithium mining in the United States, plans to increase annual production to 500,000 tons by 2030, but said this is still not enough to meet projected demand.
This is the advantage of sodium-ion batteries. Although sodium-ion batteries have not yet received the same attention as lithium-ion batteries, they are becoming one of the major technological breakthroughs that will realize the dream of electrification. Sodium-ion batteries are similar in design to lithium-ion batteries and can be manufactured using the same or similar industrial processes. In this type of battery, sodium ions replace lithium ions in the cathode, and lithium salts in the electrolyte (the liquid that helps transport charge between the battery electrodes) are replaced with sodium salts.
Sodium-ion batteries are not a new concept, but the idea of mass-producing them has only gained traction in recent years. Sodium is much more abundant than lithium, making it cheaper and easier to obtain, while also being less susceptible to geopolitical tensions. So far, the highest price of sodium carbonate is only US$286 per metric ton, while the price of battery-grade lithium carbonate is as high as US$20,494 per metric ton.
Chemists also found that layered oxide cathode batteries made using sodium can achieve energy densities comparable to lithium iron phosphate (LFP) batteries without the need for expensive metals such as cobalt or nickel.
Earlier this month, a team of Japanese researchers at Tokyo University of Science revealed they had developed a high-capacity cathode for sodium-ion batteries using nanostructured hard carbon. The energy density of this battery can reach up to 312 Wh per kilogram, which is about twice that of lithium iron phosphate batteries. To put this in perspective, this is also 1.6 times the energy density of the most advanced sodium-ion batteries from more than a decade ago.
Another advantage of sodium-ion batteries is their ability to withstand a wider operating temperature range – from minus 30 degrees Celsius to 60 degrees Celsius (minus 22 degrees Fahrenheit to 140 degrees Fahrenheit), or even 80 degrees Celsius (depending on the chemistry used). That’s why companies like Ferradian have begun trialling sodium-ion battery devices for stationary energy storage in Australia.
Earlier this year, a joint venture between Volkswagen and Jianghuai Automobile Group unveiled its first electric sedan powered by sodium-ion batteries. The car's 25-kilowatt-hour battery has a relatively short range of just 250 kilometers (155 miles), but both companies tout fast charging, better low-temperature performance, and longer battery cycle life with slower capacity loss as it ages.
Faradion CEO James Quinn said the safety advantages of sodium-ion batteries cannot be overstated. Lithium-ion batteries need to be charged to more than 30% before shipping, while sodium-ion batteries can be safely discharged to 0V like a capacitor, eliminating the possibility of thermal runaway due to short circuits. As you can see in the video above, piercing a sodium-ion battery while it's fully charged doesn't turn it into an incendiary bomb.
While Faradion is currently focused on stationary energy storage, other companies such as Natron Energy have begun venturing into the automotive industry. The Santa Clara-based startup is using a common material called Prussian blue to make electrodes for sodium-ion batteries, which are rated for between 50,000 and 100,000 charge-discharge cycles. They can also be fully charged in 15 minutes or less.
Natron recently formed a partnership with Clarios International to mass-produce sodium-ion batteries at the latter's facility in Meadowbrook, Michigan, using the same equipment currently used to produce lithium-ion batteries. Natron said that with the expansion of production scale in the next few months, it will become the world's largest sodium-ion battery factory.
It remains to be seen what the future holds for sodium-ion batteries, but unlike many solutions that have yet to make it out of the lab, they do look promising. It all depends on how material prices fluctuate as the technology matures and more factories begin mass-producing sodium-ion batteries.
It is expected that by 2030, the global annual production capacity will reach 186 million kilowatt hours, and the annual production capacity of lithium-ion batteries will be 6.5 terawatt hours. This means that sodium batteries may not take over the dominance of lithium batteries anytime soon. However, sodium batteries appear to be increasingly attractive in a variety of applications and are likely to become the solution of choice in the long term.
