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The power tool company behind DeWalt, Black & Decker and Craftsman is testing batteries that don’t explode

The power tool company behind DeWalt, Black & Decker and Craftsman is testing batteries that don’t explode


Amionx SafeCore might bring nigh-fireproof batteries to power tools

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Illustration by William Joel / The Verge

Here are two things you probably don’t know:

One, a whole bunch of the top power tool brands — including DeWalt, Black & Decker, Craftsman, Porter-Cable and more — are all owned by the same company, Stanley Black & Decker. Those 20-volt lithium-ion battery cartridges you stick into your drill, circular saw and weed whacker are all pretty much the same thing.

Two, a tiny startup called Amionx has figured out how to make lithium-ion batteries that don’t explode when they’re crushed, shot, or stabbed.

Which is why I’m pretty excited — if maybe prematurely — that Stanley Black & Decker has just announced it plans to put Amionx’s “SafeCore” battery technology into an actual product. I say prematurely, because neither Amionx nor Stanley would give me the foggiest notion when or where the first SafeCore battery might appear.

To be clear, that’s the entire announcement: a licensing deal has been signed to commercialize this technology, with no other details. A Stanley representative would only tell me that it’s “evaluating the technology to see where it could be applicable in our products,” and that “Amionx’s technology is attractive as it can potentially, make battery cells inherently safe under abuse.”

The word “potentially” was underlined in Stanley’s email.

Admitting some products are safer than others might be a risky move

There may be a good reason for Stanley’s hesitance to say more, though. Even if the power tool giant were to take the drastic step of putting this technology in every battery it buys from now on, it wouldn’t want to admit its existing batteries aren’t as safe as can be. Because even though lithium-ion battery explosions aren’t that common (1 in 10 million is the number experts usually quote), they do happen from time to time — and occasionally you get a product like the exploding hoverboard or the flaming Galaxy Note 7 phone. No sense in scaring customers away.

Lithium-ion batteries are inherently flammable. While they’ve made their way into practically every portable gadget because of how much power they can put out at a given size and weight, they also contain a flammable electrolyte that’s one short-circuit away from bursting into flame. If the incredibly thin separator between the positive and negative sides of a battery gets punctured, you can easily wind up with a fire.

But last year, Amionx showed me a secret sauce that can be applied to a battery’s electrodes, without changing the manufacturing process, that can stop a fire before it occurs — kind of like a fuse. The company won’t say what the recipe is, only that it creates a physical gap between the electrode and current collector when a battery starts to heat up, which forces electricity to take a slower, more difficult path through the cell and stop short of an explosion.

Having seen one of these batteries take a bullet before my very eyes, not to mention getting crushed and stabbed, my brain immediately jumps to the possibilities for the nearly fire-proof batteries if Stanley decides to make them a standard.

Power tools aren’t the endgame

It’s not that I’m champing at the bit for a safer battery for my DeWalt impact driver and leaf blower, or my Black & Decker string trimmer or pole saw. But if Amionx proves they can scale to the hundreds of interchangeable-battery power tools that Stanley offers today, it might open up the industry’s eyes to putting them in laptops, phones, and electric vehicles where we could really use a meaningful battery life boost. The company says its safer batteries will need fewer protections, leaving more room for battery instead of heavy, rigid casings or protective circuits. The weight savings could mean more range for electric cars, and be a small assist in helping electric airplanes actually get off the ground.

But it also depends on whether SafeCore can scale, and whether companies will take Amionx seriously even if it can. The company tells me it still hasn’t signed a major battery manufacturer to actually produce the cells, though it does have its own miniature facility that can satisfy some demand by itself. It sounds like a chicken-and-egg scenario where Amionx is going to have to find some customers to produce that demand first. But it’s not clear how much demand Stanley is going to generate, because we don’t know how seriously it’s pursuing the idea — and though Amionx also has another signed partner, it won’t even say who they are beyond a “large, well known company that produces consumer electronics.”

I’ve been wondering for many months if there’s some fatal flaw in the idea, something I’ve overlooked that explains why SafeCore is too good to be true. Perhaps the world is waiting for solid-state batteries instead? But I have to admit that signing the company behind some of the best-known brands of power tools to work on a product, even if we don’t know which product, sounds like a pretty huge step in the right direction.