Quick-charge batteries promise smaller, lighter, and longer-lasting everything, from electric cars to laptops.
Image: Oliver Sved/Shutterstock
Battery charge-time is more than a matter of convenience. In the case of electric cars, it could be the difference between full-on adoption and affluent novelty, or the difference between a clean(er) transportation future or one that clings to portable combustion machines until the bitter end, because who can even wait for things nowadays. Indeed, an issue now is how long electric cars take to charge: doing it at home, which is the ideal case, can take many hours—overnight—while doing it at a DC current-based, high-voltage station can still take longer than an oil change.
It would be nice if rolling up to an electric station involved the same commitment as its fossil fuel counterpart, and that's the (implied) promise of (paywalled) research released this week from a team at the University of California, Riverside: batteries that charge up 16 times faster with 63 percent more capacity and 40 percent less mass.
The technology described, like a whole lot of change-everything materials science now, is based on carbon nanotubes, peculiar molecules that naturally form into cylindrical shapes with walls the thickness of a single atom. At certain dimensions, the nanotubes become extraordinary conductors of thermal energy and electricity. Basically, the battery design forms clusters of these nanotubes into cone shapes, which are then "decorated" with silicon. These silicon-spiked cones make up the anode portion of a regular lithium-ion battery, the spot where charge collects and positive current flows into the device, presumably from some conventional charger, but it's well suited for very high voltages.
The mass and size differences are attributable to the silicon embedded on the anode, a relatively new idea set to replace the usual graphite anodes in the near future. The speed, however, comes courtesy of the newly introduced nanotube structure. The reason is twofold. One, the overall structure allows a more seamless connection to the electrochemical guts of the battery, facilitating more efficient charge transfer. And two, the carbon nanotubes themselves provide new channels along the anode through which the battery's electrolyte solution can travel, allowing faster electrolyte access.
"Silicon is a type of anode material that is receiving a lot of attention due to its highest known theoretical gravimetric and volumetric capacity values of [about] 4.200 [milliamp hours per gram], which is 10 times higher than commercial graphite based lithium ion battery anodes," lead researcher Wei Wang explained an email.
Pair this up with another looming technology that should make it possible for charging cords and other wires (maybe even your clothes) to store electricity as well as move it, and/or wireless charging, and the days of heavy electronics are over. That changes the electronics future more than you might think.
Tesla's much-vaunted opening up of its charging patents, a move which really just corrects the company's weird miscalculation that propietary charging stations (Tesla stations for Tesla cars) had any place in an already niche market, is interesting to consider in light of this potential new, superior battery technology. It's probably a genuine coincidence that it was unveiled the same week as Elon Musk's patent announcement, but UCR's is a breakthrough (a patented and already licensed breakthrough, Wei Wang added, noting that the licensee is confidential) that could well make those patents kind of trifling, depending on how quickly silicon-anode batteries hit the market.
Tesla's lithium-ion batteries bank heavily on graphite, after all, and the future of quick-charge, what one might argue is a much realer factor in widespread EV adoption, is heading toward silicon. The patent giveaway was touted by Musk as just some open-source benevolence with a side of business reasoning, but in a Q&A with reporters the PR stink was unshakable, as Musk characterized another car maker's decision to use non-Tesla batteries as "suboptimal," not so subtly implying that the only reason everyone isn't using Tesla technology is because of those darn patents. Joseph White summed up the patent move in a few cutting and on-point words: "please use our batteries."
More accurately, it might be, "please use our batteries ... before they're obsolete."