Welcome back to The Electric!
This is the second of our two-part series on the surprisingly fast arrival of next-generation battery technologies. Last week we looked at the imminent commercialization of electric vehicles powered by high-concentration silicon anodes. This week we turn to the even more unexpected debut of sodium-ion batteries, which do away with lithium.
When Michelangelo created his masterpieces in the 16th century, he didn’t settle for just any source of blue pigment. He insisted on—and often received—royal access to ultramarine, an exorbitantly expensive hue made by crushing lapis lazuli, a gem found primarily in northeastern Afghanistan. But most artists were relegated to lesser blues that faded over time and even turned brown. An accident of fate around 1706 changed all that: A German chemist named Johann Jacob Diesbach, trying to create a red pigment, inadvertently mixed his precursor material with an oil containing the blood of cows. The result was not red, but a deep blue. Diesbach had invented what became a wildly popular pigment for dyes and paints—Prussian blue, named for its invention in Berlin, then the capital of Prussia.
And that’s where things stood for Prussian blue—until 2009, when Robert Huggins, a Stanford University materials science professor, got the idea that the pigment, sold as a crystalline powder, might also work as a battery cathode. Huggins recalled that decades earlier, researchers had discovered that Prussian blue could be charged and discharged for use in electronic displays. So why couldn’t it also be charged and discharged for energy storage?
Huggins’ brainchild led to an entirely new type of battery that eliminated lithium, the most popular battery material, and replaced it with sodium, an element 1,000 times more prevalent in the Earth’s crust. Until recently, researchers largely believed that commercialization of sodium-ion batteries was decades off. But a confluence of the industry’s manic pace of growth and a critical shortage of battery materials has catapulted sodium-ion batteries into commercial use: