The sodium-ion battery has been the subject of intense scientific research for years, primarily because sodium is one of the most abundant elements in the world (it’s the main ingredient in table salt), whereas lithium, while not exactly rare, is much harder to source in commercial quantities. The biggest obstacle standing in the way of the acceptance of sodium-ion batteries in industry is that they have a lower energy density that lithium-based batteries.
But the dominance of lithium batteries is under threat at the present time. The cost of lithium has increased by 700% since the beginning of this year, forcing battery manufacturers and automakers to consider options that were previously not feasible. CATL last year announced it has created a sodium-ion battery with an energy density of 160 wH/kg and expects to increase that to 200 wHkg by 2023. It has already started production of its first generation sodium-ion battery cells.
Altris is a Swedish company that is also deeply involved in manufacturing sodium-ion batteries. According to Chemical and Engineering News, it will build its first commercial facility at Sandvik Materials Technology’s site in Sandviken, Sweden. Altris plans to begin building the plant in the coming weeks and open it in early 2023. The factory will have an initial capacity of 2,000 metric tons per year of its Ferrum cathode material, which features sodium, iron, carbon, and nitrogen compounds.
On its website, the company says its research focuses on the development of electrodes that are comprised entirely of highly abundant and safe materials. A pilot production line is already in operation and demonstrating the feasibility of implementing the sodium cathode technology as a “drop-in” replacement for conventional cathodes. That’s important because it means no major changes in the manufacturing process are required.
The company calls its iron and sodium based electrode material Fennac, which is readily produced in large quantities via a low energy process. “Fennac is high sodium content Prussian White powder which is a cathode material for the next generation of environmentally friendly sodium ion batteries. Composition is NaxFe[Fe(CN)6] with x>1.9,” the company says. “This material is ideal as performance positive electrode in sodium-ion batteries and can be paired against anode materials which do not contain sodium. Ideal storage is under inert conditions in order to maintain quality over the longer term. Nominal voltage 3.25 V on average, capacity ~160 mAh g-1.”
The competitive energy density makes the material suitable for sodium-ion batteries applied for stationary energy storage, to support the grid and other applications where a low cost alternative is attractive.
Sodium batteries are not yet ready for use in electric vehicles, but hang on. The final chapter hasn’t been written. Battery technology today is where videotape recording was in the 1980s. First there was Betamax, then VHS, then Blu-ray, then CDs and now it’s all done online. The internal combustion engine of today is a jewel of engineering prowess, but it has been in development for over a century. You would expect most of the bugs to be worked out by now. (Older readers may remember when a gasoline-powered car was considered ready for the scrap heap after 50,000 miles.)
Are sodium-ion batteries the next new thing? If lithium, nickel, and cobalt prices remain in the stratosphere, they very well could be. In the final analysis, safe, low cost grid-scale battery storage for renewable energy is probably more important in the battle against fossil fuel inspired climate change than building electric cars. Pass the salt, please!