It won’t come as a surprise to you that the lithium used in most batteries largely comes from “inconvenient” places: Australia, Chile, China, Argentina, and Zimbabwe are among the leading producers. The U.S. ranks fifth in the world for zinc production, though, which makes the concept of a zinc-air battery exceptionally attractive to companies based here. The chemistry was first commercialized in 1932, but low current capacity and difficulty recharging has restricted their use to things like hearing aids. Taiwan-based startup Thunderzee Industries reckons it may have solved enough of these problems to bring the zinc-air battery to larger appliances—and even cars, news which made something of a splash at CES 2021.
Benefits of Zinc-Air Batteries
Energy density and specific energy (per weight) tend to be great because atmospheric air is one of the reactants, and it’s, well, “light.” (Each amp-hour of capacity consumes about a liter of air.) They also have a long shelf life if you simply seal away the air. And voltage remains quite constant throughout the discharge cycle, because the cathode properties don’t change. They’re stable, they’re nonflammable, the materials are inexpensive, and they’re environmentally friendly.
Drawbacks of Zinc-Air Batteries
Many button-style batteries are zinc-air. These are disposable, non-rechargeable and typically only useful in single-cell use, as stacking them complicates the task of supplying sufficient air. Some zinc-air setups have functioned like fuel cells, with fresh zinc powder replacing spent zinc oxide being removed—not terribly handy for electric vehicles.
Has Thunderzee Cracked the Zinc-Air Battery Code?
“We have made a major breakthrough in electrochemistry of metal air batteries. We developed high-power metal/air fuel-cell components: air cathode, ion membrane, and metal fuel formulation,” Thunderzee founder and CEO Andy Lin says, suggesting that such fuel cells can be widely used in military and commercial applications. That still sounds to this tech reporter like a battery that doesn’t get plugged in, but rather requires replacement of a zinc slurry. With only three patents filed to date and many more in process, Lin and Thunderzee are understandably cagey about the specific details of their technology.
The zinc-air battery is undeniably attractive on so many levels, and the world is desperate to commercialize a breakthrough in some type of metal-air battery, which explains the attention lavished on the scant information provided by Thunderzee. Color us skeptical. Thunderzee reports having secured $5 million in series A funding that will be put toward building a lab to manufacture small production samples and hire more engineers to speed up the product design. We’re reserving further comment/enthusiasm until we can learn a lot more about the technology—or at least until Thunderzee.com provides more than the “New website is under construction…Will be back soon” message it displays as of this publication.