The Electric: Do Western Car and Battery Companies Have a Sodium Blind Spot?
For all the talk of lithium as the driver behind the nascent electric vehicle industry, a second, much less-discussed battery metal has been attracting recent attention. It is sodium, a cheap ingredient of ordinary salt. Long derided as lithium’s poorer cousin in terms of battery value, it is surprisingly showing better performance in some electric vehicles. Since sodium is found nearly everywhere, leading Chinese battery makers and some Western analysts are now calling it a potential replacement for increasingly scarce lithium.
Sodium may be yet another instance in which Western companies are waiting too long to dive into a big shift in batteries. So far, Western, South Korean and Japanese companies have largely ignored sodium, with some industry veterans dismissing it as part of an elaborate plot by China to talk down lithium prices and profit from lower costs. Meanwhile, as many as two dozen Chinese battery makers have announced plans to develop such batteries for stationary storage and later EVs. Their aggressive moves mirror action by Chinese companies across the battery industry the last dozen years. They have been grabbing control of everything from mines to battery manufacturing, a strategy that has put them well ahead of their Western rivals.
Driving interest in sodium is a looming shortage of lithium. Supplies of the latter metal are forecast to fall severely short of demand this decade, limiting how many EVs can be produced. Sodium accounts for 2.3% of the world’s crust, making it more than a thousand times as abundant as lithium. The more plentiful supply also makes it cheaper: Estimates are that sodium-ion batteries can be produced for under $100 per kilowatt-hour, 33% less than current lithium-ion batteries, and when produced at volume, the cost could drop by more than half, to $40/kWh, experts say.
Skeptics, though, point out that while sodium is theoretically cheaper as a battery metal, a number of other materials are required to make it work in an actual battery pack, raising its ultimate cost considerably. And while sodium may relieve one supply bottleneck—that of lithium—the use of sodium could exacerbate shortages of another battery metal: nickel, which sodium-ion electrodes may require.
Some Western industry hands suspect that China is talking up sodium ion at least in part to keep downward pressure on lithium prices, which are down a whopping 63% from a November peak. The stock prices of lithium mining companies have fallen in tandem. Lithium industry analyst Joe Lowry has suggested that the specter of sodium ion’s arrival eating up part of lithium’s market has spooked traders.
But lithium’s price fall is likely related more to the law of supply and demand: Chinese battery companies are drawing down lithium stockpiles accumulated toward the end of 2022, and they had relatively soft demand for batteries in the first two months of this year. Thus they bought less lithium than usual, creating a surplus.
An Idea That Started 20,000 Leagues Under the Seas
The idea for sodium batteries goes back a century and a half. In 1870, Captain Nemo powered his submarine with a sodium battery in Jules Verne’s “Twenty Thousand Leagues Under the Seas.” Nine decades later, researchers at Ford developed a battery that combined sodium and sulfur, but it went nowhere in terms of use in a car because it needed to be heated to a dangerous 350 degrees Celsius (660 degrees Fahrenheit). Work on sodium batteries continued through the 1970s and the early 1980s, but events overtook the chemistry’s promise: Oxford researcher John Goodenough invented a way for lithium to work in a battery, and Sony commercialized it for use in the first handheld video cameras.
Sodium is inferior to lithium in multiple ways: It has half the energy density, so the driving range of EVs equipped with a sodium-ion battery is relatively short—there are no 300-mile sodium-ion batteries, for example. Also, sodium atoms are much larger than lithium ones, weigh 3 times as much and have trouble finding a way in and out of the most popular EV cathodes and cathodes. That means sodium-ion batteries require new anodes and cathodes.
In the summer of 2021, China’s Contemporary Amperex Technologies Ltd., the world’s largest battery manufacturer, announced that it had produced a sodium-ion battery with surprisingly high performance. CEO Robin Zeng said the battery delivered energy density of 160 watt-hours per kilogram in an electric vehicle battery, approaching the performance of lithium-iron-phosphate, a commercial cathode used widely today for low- and mid-range EVs. CATL made the cathode from Prussian white, a material combining iron and manganese, and the anode from porous hard carbon that allowed the sodium ions to move freely, and Zeng said the resulting battery could charge to 80% of its capacity in 15 minutes.
He said CATL would first offer the battery to electric power stations for use during peak electricity demand. He said a later EV battery would be a hybrid combining sodium and lithium. Executives of Western companies and outside researchers expressed skepticism, especially about CATL’s claim that it would next produce a sodium-ion cell delivering 200 Wh/kg of energy density, equaling the performance of the current best LFP and sufficient to power an EV for 250 or more miles. Western executives and analysts continue to wonder how CATL manages to get sodium ion—a chemistry thought to be good for 100-mile cars and little more than that—to deliver 2.5 times the distance.
As is the case with much of what happens in Chinese technology, CATL’s work aligned with official government policy—China’s five-year plan called for sodium-ion research. But over the subsequent 18 months, lithium prices climbed as much as 14-fold over multiyear lows hit in 2020. One Chinese company after another, including a couple that had Western partners, announced that they, too, were getting into sodium ion.
The plans include the following:
VW-backed JAC Motors in February unveiled the Sehol E10X, an EV powered by a sodium-ion battery produced by HiNa Battery Technology Co. that in tests delivered 120 Wh/kg at the pack level. In December, HiNa also started up the world’s first large sodium-ion production line, a 1 GWh factory in Fuyang, China.
Renault-backed Jiangling Motors, which has said that this summer it will release the EV3, a short-range EV, is using a sodium-ion battery it tested from Farasis Energy, a Ganzhou, China, company.
Huizhou, China-based battery developer EVE Energy has unveiled a cylindrical sodium-ion battery.
Changzhou, China-based battery developer SVolt has said it is working on a sodium-ion battery that currently achieves energy density of 100 Wh/kg.
A report in November said battery and EV manufacturer BYD, China’s leading EV maker, planned a sodium-ion battery for its electric Seagull, which is to be released later this year. A second report said the car would cost from $9,000 to $11,000. BYD denied the reports.
In all, Benchmark Mineral Intelligence said it has identified 28 sodium-ion gigafactories planned by 2030 with a capacity of 107 GWh, with all but four small ones based in China. In a report last week, Matt Fernley, editor of Battery Materials Review, forecast that the sodium-ion factories will produce even more batteries—440 GWh of production capacity.
Kevin Shang, an analyst at Wood Mackenzie, an energy research firm, said the attention to sodium is a product of the surge of lithium prices since 2020. Few of the Chinese companies that have announced new sodium-ion products are actually working on them, Shang told me. “Some people are just trying to follow the fashion and aren’t really serious about it,” he said.
How to Make Sodium Work in an EV
Some Western foreign policy analysts have cited sodium ion as an example of China continuing to march out ahead of the West. No major non-Chinese auto or battery maker has announced a product or even work on a sodium-ion battery, and the presumption in the industry is that sodium-ion EVs will arrive at large scale in the West only in the 2030s.
Therein lies the danger—is the West again setting itself up to again be outmaneuvered on the battlefield of batteries and eclipsed by the Chinese? In other words, does the West have a blind spot when it comes to sodium ion, in the same way that it ignored LFP—another low-tech chemistry Western companies derided as unworthy of their attention—even as Chinese companies hammered it into one of the best commercial cathodes? Venkat Viswanathan, an engineering professor at Carnegie Mellon University, said the answer is yes. “Sodium isn’t seen as an attractive research area,” he told me. “The West tries to do technology plays, [but] sodium ion is an inferior technology play. You hardly have any sodium-ion startups.”
There are lessons for sodium in next-generation lithium-ion batteries. The stretch play for lithium-ion developers is to use pure lithium metal foil, a material that can cause an explosion but that if tamed could increase driving range by 50%. So it could be with sodium ion, too: In January, Advanced Research Projects Agency—Energy, or Arpa-E, a Department of Energy agency that incubates pre-commercial energy technologies, awarded a three-year, $3.2 million grant to 24M Technologies, a Cambridge, Mass., battery manufacturer, to develop a sodium-metal battery.
Viswanathan, who is part of the 24M team, said the idea is to use foil made of pure sodium metal in a battery rather than crumbs of sodium ions as is currently the case. This approach would produce a battery equivalent to current top-of-the-line EV lithium-ion batteries, Viswanathan said. But, like lithium metal, sodium metal produces spiky growths called dendrites that can cause shorts and explosions. Maria Forsyth, a battery researcher at Australia’s Deakin University who works on sodium metal, told me it is not nearly ready for commercialization in EV batteries. There is “too much uncertainty and safety issues to consider,” she said.
Either way, the deployment of sodium-ion or more-advanced sodium-metal batteries promises to take up some of the slack in low-end to medium-range EVs and energy storage, relieving the constraint on the EV supply. For three decades, the West has made repeated errors of judgment in battery development, allowing first Japan, then South Korea and finally China to take control of commercialization. With its chronic blind spot, the West is so far making the same mistake.