Will sodium displace lithium as the key to high-density, long-lasting batteries to power smart phones, electric vehicles, and turn intermittent solar and wind power into dispatchable electricity?
Are iron-air batteries heavyweights aimed at becoming serious contenders for the battery energy storage crown?
Lithium’s strength is known. It is a muscular lightweight, the lightest metal on the periodic table with an atomic number of 3. It is also a good conductor of electricity and heat, meaning it can constitute the basis for high-density light batteries.
Its weaknesses are also familiar. Like other alkalides, it is highly reactive and flammable. Perhaps most significantly, it is also scarce, which means it is expensive.
Finding an acceptable replacement that overcomes all or a significant amount of lithium’s problems while preserving its virtues is a worthwhile endeavor. That’s why the Department of Energy in January launched – perhaps irrelevantly – a $131 million program to “advance research and development (R&D) in electric vehicle (EV) batteries and charging systems, and funding for a consortium to address critical priorities for the next phase of widescale EV commercialization.”
It’s a bit ironic that what DOE is calling the “advanced battery consortium” is a reprise of a failed 1990s Clinton administration program combining the California Air Resources Board, DOE, and the Electric Power Research Institute to try to come up with an acceptable EV battery. They called it the “U.S. Advanced Battery Consortium.” It partnered with another Clinton initiative called the “Partnership for a New Generation of Vehicles.” It also failed.
Earlier this month (July 10), Chemical World reported, “The world’s largest sodium-ion battery has gone into operation in Qianjiang in China’s Hubei province.” By comparison to its big lithium brothers, the Chinese battery developed by state-owned Datang Group is small — 50MW/100MWh – but advocates of the Na-ion battery have big plans.
The advantages of a sodium-based batteries are straightforward. Sodium is plentiful, cheap, and fairly light (atomic number 11). If the technology were able to dethrone lithium-ion batteries, the result could be a major step forward, particularly for electric vehicles and battery energy storage systems.
The EV Design & Manufacturing website lays out the promise: “With limitations and challenges associated with lithium-ion batteries, sodium-ion has emerged as a potential contender as a more sustainable and cost-effective alternative. With tangible benefits already emerging, the interest in sodium-ion only continues to grow, reflecting a shift toward exploring solutions that align with the increasing demand for reliable and eco-friendly energy storage systems.”
Power Technology magazine says, “Sodium-ion batteries are not only improving at a faster rate than other long-duration energy storage technologies but they are also set to be cost comparable with the cheapest forms of dispatchable power, and therefore enter mainstream use, as early as 2027.”
Then there are iron air batteries, which could be a better solution for large stationary batteries, specifically for battery energy storage systems. The obvious characteristic of the Fe-based batteries is weight. Iron is heavy (atomic number 26). But it is ubiquitous. As Wikipedia notes, “It is, by mass, the most common element on Earth, forming much of Earth’s outer and inner core.”
If the Chinese are telling the truth, they may be farther along on sodium ion electric vehicles than their western competitors. Hong Kong-based Jiangxi Jiangling Group New Energy Vehicle Co (JMEV) claims it has rolled out a small car powered by sodium-ion batteries made by Farasis Energy, a U.S., German, and Chinese firm, at factories in Ganzhou and Zhenjiang. Farasis pioneered lithium-ion pouch battery cells.
According to Farasis, the sodium-ion batteries in the JMEV feature a “combination of layered oxides and hard carbon.” The claim an energy density of 140-160 Watt-hours/ kilogram,” and “over 91 percent discharge capacity retention at -20°C (-4°F).” The small JMEV cars claim a range of 251 km (156 miles), limited compared to most EVs now available worldwide. Farasis says it plans to roll out batteries with greater power density: 160-180 Wh/kg this year and 180-200 Wh/kg in 2026.
Iron-air batteries are too heavy for use in EVs. But their weight is no obstacles in stationary applications, such as electricity storage. The main raw material of this technology is rust (iron oxide), which abundant, non-toxic, inexpensive, relatively safe, and environmentally benign.
In a 2022 article, Scientific American reported, “Although iron-air batteries were first studied in the early 1970s for applications such as electric vehicles, more recent research suggests that it may be a ‘leading contender’ to expand the nation’s future supplies of green electric power for utilities, according to George Crabtree, director of the Joint Center for Energy Storage Research at Argonne National Laboratory.”
The Scientific American article described the technology as “a slab of iron, a water-based electrolyte and a membrane that feeds a controlled stream of air into the battery. When discharging, the battery breathes in oxygen from the air and converts iron metal to rust. While charging, an electrical current converts the rust back to iron and the battery breathes out oxygen.”
In addition to low cost, the iron-air batteries could stay in the game far longer than the now-conventional Li-ion batteries: up to 100 hours rather than the four hours characteristic of the lithium technology. This could be a major selling point to utilities that suffer prolonged outages (Texas, perhaps?).
A Massachusetts firm founded in 2017 by former Tesla battery chief Mateo Jaramillio and MIT battery scientist Yet-Ming Chiang is putting a major effort into utility-scale iron-air battery storage. Form Energy (FE, clever, huh?) has raised over $800 million from investors including the Bill Gates Breakthrough Energy Ventures and Luxembourg-based multinational steel company ArcelorMittal SA. The company has just completed a 55-acre battery factory near Weirton, W.Va., in the heart of the Appalachian rust belt. Form Energy says the factory is a $760 million investment.
Will these iconoclastic technologies succeed? Not necessarily. Their products don’t exist at scale. Lots of real world questions remain. Will they work reliably for long periods? How much will they cost to make and install? How much will they cost to run? Will the market embrace them sufficiently to yield a profit? Will other, better solutions to the problems they are addressing emerge? Stay tuned.
–Kennedy Maize