About three miles west of Colorado State University, a small team of scientists is working on the next revolution in batteries. The startup, Prieto Battery, has gained recognition — and high-profile customers — for rebuilding the lithium-ion battery from scratch. Its battery is nonflammable, bendable, inexpensive to make and, in theory, much longer lasting.

“Our mission is to make a great battery that will charge really fast and store a lot of energy but use methods that are environmentally friendly,” said company founder and CEO Amy Prieto, an associate professor of chemistry at CSU.

If you know anything about batteries, that is a tough order.

The last major battery revolution happened in the early 1990s, when Sony became the first company to commercialize lithium-ion batteries. Today, we use such rechargeable batteries to power our mobile devices, from smartphones and laptops to electric cars. There have been spurts of improvements, including faster-charging versions — but also setbacks, most notably Samsung’s exploding battery fiasco, which led airlines to ban Galaxy Note 7 phones last year.

The quandary has been that rechargeable batteries are either built for power or longevity, not both. A long-lasting, fast-charging cordless power tool? If only, wishes the folks at Stanley Black & Decker, whose venture arm has invested in Prieto.

There’s also the eco factor, or lack thereof. In states such as California, it’s illegal to trash batteries because chemicals inside could leak in landfills and pollute the groundwater supply.

And then there are the safety issues, even with smartphones.

“It’s like you are carrying a hip flask of gasoline,” said Donald Saxman, a battery analyst for market researcher BCC Research. “Of course you want to reduce the risk as much as possible. And they are working on that. But at the same time, with any engineering, you have to balance risk, performance, manufacturing, price and size. You can probably make a pretty safe battery with a lot of containment if you want a 3-pound battery on a 10-ounce iPhone. People want to reduce the risk but won’t be up for that, or spending $1,600 on it.”

Batteries are big business. According to the Consumer Technology Association, wholesale revenues from primary, rechargeable and specialty batteries for consumer devices reached $6.6 billion last year. Sales are expected to grow to $6.7 billion this year.

But change has been minimal.

“In the 1990s, lithium-ion came on the scene and started displacing cadmium. I don’t see anything replacing lithium-ion batteries in the next five to 10 years,” said George Kerchner, executive director of PRBA — The Rechargeable Battery Association, adding that recent advances have been on the manufacturing side. “I certainly see things improving energy density and improving safety. But it won’t be something next year where you see a new battery technology displacing lithium-ion. Change is relatively slow in the industry.”

Another reason why it may seem like batteries haven’t changed much is that improvements are outdone by the devices that use them, said Saxman, who has covered the industry for so long that he’s skeptical that any new technology will become the next big thing.

“The technology is improving a whole lot slower than demand is,” he said. “The biggest issue is that tablets, smartphones and, to a lesser extent, laptops keep adding more and more features. They keep needing more electricity because they’re hooking up to GPS and wireless that soak up power.”

Prieto’s technology, however, may finally give batteries the advantage. Its battery is so promising that Stanley Ventures, Intel Capital and others have invested $10 million in the company and are first in line for the end product. In April, Moses Lake Industries, the Washington state manufacturer known for fine-tuning chemical processes for chipmakers, teamed up with Prieto to make the new batteries at scale. The first commercial prototypes will be ready by October. If all goes well, Prieto batteries could start showing up in consumer products by 2020.

“The potential for Prieto is very great because of the energy density and the safety,” said Mark Willey, senior director of technology for Moses Lake Industries, which has never made a battery. “When I think of their technology, they can pack more energy into a smaller form factor, and it’s safe. It’s not going to blow up because of the configuration.”

Rethinking the battery

To understand what makes Prieto’s batteries so special, you must ditch any notion you have about what a battery looks like.

Prieto batteries can be very thin — or thick — and cut to fit a variety of inconceivable shapes, from a delicate wedding ring to the frame of a car. But thinness isn’t the key. It’s how the typical layers of a battery are mashed together to allow for greater energy storage and to speed up charging and discharging. Usually, the two don’t mix.

“If you want to make your battery really fast, you have to make the layers really thin. But then your battery doesn’t store as much energy,” Prieto said. “There is no way to decouple these two factors using a conventional 2-D architecture. That’s why what we’re developing is a 3-D battery.”

The Prieto battery still relies on the main concept of a battery — the negative (anode) and positive (cathode) sides of the battery swap electrons to produce energy.

But its 3-D architecture is the key. Instead of flat sheets of metal found in conventional batteries, Prieto starts with a foam and coats it with the necessary layers of battery chemistry.

Technically, here’s how Prieto builds its 3-D battery:

1.It starts with a copper foam substrate.

2.Using an electroplating process, the foam is coated with the copper antimonide anode.

3.Then it’s coated with a solid state electrolyte.

4.Then it’s coated with a lithium cobalt oxide cathode slurry.

The three separate layers seep into the crevices and edges of the foam, which has greater surface area to store energy. The 3-D texture also shortens how far electrons must travel, which speeds up charging and discharging.


Most lithium-ion batteries are made with flat layers of metals and other chemicals. Prieto Battery, based in Fort Collins, still has layers but they are intertwined in the same way you’d clasp your fingers of both hands together. The process starts with a copper foam substrate that is dipped in an anode mix, then a solid electrolyte and then then coated with a cathode slurry. Since it’s no longer flat but rather 3-D, the Prieto battery can store more energy and charge and discharge faster.

Prieto Battery

Most lithium-ion batteries are made with flat layers of metals and other chemicals. Prieto Battery, based in Fort Collins, still has layers but they are intertwined in the same way you’d clasp your fingers of both hands together. The process starts with a copper foam substrate that is dipped in an anode mix, then a solid electrolyte and then then coated with a cathode slurry. Since it’s no longer flat but rather 3-D, the Prieto battery can store more energy and charge and discharge faster.

For a client such as Stanley Black & Decker, that means cordless power tools would maintain high power for longer periods. For electronics makers, including Intel, this means a smaller battery will free up space on a board or device for other components and functions. But more importantly, this means a product could go mainstream.

“We wouldn’t have engaged with them if it hadn’t been innovative,” said Willey, with Moses Lake. “The key thing for MLI is that they (Prieto) have a clear path for sales through Stanley Black and Decker and Intel. It’s not just a startup. They have actual investors and customers who would actually use their product.”

Amy Prieto doesn’t come from a battery background. She’s a synthetic chemist who specializes in creating new materials, “which is a lot like cooking,” she said. “I love problems where people already know what they want but nobody knows the right material.

But when she joined CSU in 2005, she hit the wall.

“Every device I could think of was limited by the battery,” she said. “So I thought that if I could make a better battery, the devices wouldn’t be limited in that way.”

She discovered that the idea of 3-D batteries was already well documented. Solid-state batteries, which won’t leak toxic liquids, were also up and coming. But no one had made a commercially viable 3-D battery. As with any new invention, sometimes things just don’t get to market because the process is too expensive, takes too long or just can’t scale up to serve a mass market.

So Amy Prieto and her graduate students made a list.

“Going back to my Bell Labs training (as a grad student), I knew that if the end goal is to make a battery that works and is useful, it can’t be made with anything that is expensive or slow,” she said. “So I made a list of things we were not allowed to use because they were too expensive or too hazardous. We ended up with electroplating.”

Electroplating is the use of an electric current to coat a piece of metal with more metal — like the making of a white-gold ring, where a gold ring is dipped in a liquid infused with dissolved white metal. The current helps the gold attract the white metal in an even layer. Prieto said this manufacturing process requires just water and citric acid, a natural ingredient found in citrus fruits.

Not everything is eco-friendly though, Prieto said. Notably, the copper antimonide is toxic. But in the electroplating process, the chemicals bind to the layers so they aren’t part of the waste product. The lithium in the battery also must be recycled. Prieto hopes that one day, chemicals such as lithium can be reused rather than sent to a landfill.

Last year, Prieto Battery demonstrated to Stanley Black & Decker that the battery works. The toolmaker used a 3-D printer to make a battery container and Prieto put eight of its batteries inside.

“We made a pack for a drill and that was exciting. We’d never powered something that big before,” Amy Prieto said. “That demo was a year ago now, and those packs are still holding a good charge.”

So far, Prieto Battery has been able to show that its solid-state lithium-ion battery can store three to five times the energy per volume than a conventional battery. It has diminished the flammability issues by going solid state. “We’ve tried to catch our battery on fire and not been able to yet, which is a good sign,” she said.

And while, in theory, the Prieto batteries could charge 100 to 1,000 times faster than conventional rechargeable batteries, the company is nowhere close to that yet. Prieto is still working to get it twice as fast.

For small items, such as a watch-sized battery, the company has demonstrated in the lab that the battery drained and recharged 1,000 cycles, which is twice as many cycles that a consumer can expect to get from their iPhone. In theory, the technology should translate to much larger batteries to fit in larger devices. The challenge is to keep that long lifespan but push the limits of performance.

With nine patents and 20 more pending, Prieto Battery is on track to deliver its first commercial prototype to Stanley Black & Decker by October. Power-tool companies have struggled with cordless tools mostly because tools need power, which uses up batteries. And the big problem with batteries is they take a long time to recharge.

“We looked at 50 different battery technologies. Prieto’s the only one we invested in,” said Larry Harper, vice president of Stanley Ventures. “Stanley sells a lot of batteries and we’re always looking for new and innovative approaches that give us more power and charge in less time. The opportunity they offered with being green was also very appealing. … This was really attractive because it had all three.”

Harper said he thinks Prieto batteries could show up in Black & Decker products by the end of next year. And Prieto plans to have battery products for Intel a year later. And if Prieto’s 3-D battery does revolutionize the world, consumers may not even realize it.

“It’s still a lithium-ion battery,” she said. “You would just notice that your phone lasts longer on a single charge. It will charge faster than a conventional one. And ideally, you won’t be reading about fires in the news anymore.”

Originally Appeared In: The Denver Post, Tamara Chuang, 06-18-2017