A common theme among doomers is that we don’t have enough of the materials we need to electrify everything. We will run out of lithium, nickel, and cobalt! But as we noted in a recent post, humans are actually pretty good at solving things when times get tough. That’s why we are not still burning whale oil for lighting.
Now researchers at the Massachusetts Institute of Technology (MIT) have cooked up a battery that is cheap to build out of cost-effective, common materials that pack in high energy density at a fraction of the cost of lithium-based batteries. Some say it will change the world.
Researcher and MIT Professor Donald Sadoway said he was specifically looking for cheap, abundant materials. “I wanted to invent something that was better, much better, than lithium-ion batteries for small-scale stationary storage, and ultimately for automotive [uses],” Sadoway told MIT News.
The problem with lithium-ion batteries is that the materials are expensive, they have flammable electrolytes and sometimes catch fire, and if you charge them too fast, spiky dendrites can form and short out the battery.
Looking for cheap, he chose aluminum for one electrode, calling it “the most abundant metal on Earth… no different from the foil at the supermarket.” For the other electrode, he selected another cheap material, sulfur, which he said is “often a waste product from processes such as petroleum refining.” A common salt was picked for the electrolyte.
It should be noted that getting alumina out of bauxite is a messy process—aluminum is nicknamed “solid electricity” because so much is needed to separate it from the alumina. And while there are literally pyramids of sulfur in Alberta, Canada, some researchers are concerned we are going to run out of the stuff. So it is not quite as simple, as Sadoway said, but it is certainly a different situation than with the ingredients for lithium-ion batteries.
The chloro-aluminate salt they chose melts at a relatively low temperature, but this battery still runs hot: 110 degrees Celsius (230 degrees Fahrenheit). However, both the charging and discharging cycles generate heat so it doesn’t need an external source; it heats itself.
Sadoway said, “You’d store electricity when the sun is shining, and then you’d draw electricity after dark, and you’d do this every day. And that charge-idle-discharge-idle is enough to generate enough heat to keep the thing at temperature.” It sounds like a high temperature, but it is easily handled with insulation.
And did we say cheap? According to the study published in Nature, “the estimated cell-level cost of our Al–S battery is as low as US$8.99 per kWh, which is 12–16% of that of today’s lithium-ion batteries.” Because the dendrites don’t form, the battery can be charged in minutes. And, because of the electrolyte:
“With such a mild superambient operating temperature, potentially as low as 90 °C, the battery will not require an active cooling system, which is absolutely critical for lithium-ion batteries in large format; instead, the moderately elevated temperature can be maintained by the combination of internal joule heating generated while cycling and by proper thermal insulation. Of utter importance and distinctly advantageous, the molten-salt electrolyte is thermally stable and non-volatile over the range of operating temperature and beyond 500 °C. It has not escaped our notice that its immunity to thermal runaway and fire makes this battery chemistry especially attractive for electric vehicles.”
However, as MIT News noted, it is also “ideal for installations of about the size needed to power a single home or small to medium business, producing on the order of a few tens of kilowatt-hours of storage capacity.” In an electrify everything world, the problem is the peak load. In California, the last 25% of capacity is needed less than 10% of the time, and the demand is met with energy that is “expensive, inefficient and environmentally unfriendly.” Batteries like these could shave the peaks and help deal with intermittency.
Many are seriously excited about this battery. Tech journalist Will Lockett calls it world-changing and concluded that “MIT has produced yet another breakthrough technology that is set to change the world for the better.”
While it might be premature to suggest this battery will change the world, it does provide yet another lesson in why we should not be climate doomers—that humans are good at figuring this stuff out. I continue to say that we can’t just electrify everything: We also have to reduce demand and consume less. But big cheap batteries will make it a lot easier.