alameda startup promises safer longer lasting batteries

By the end of the decade, the batteries that power your car or home and maybe your devices could store more energy, last longer before they need to be replaced and be made in the United States — thanks in part to an Alameda startup.

New Developments in Battery Technology

Anthro Energy says it has developed a new kind of electrolyte, the material inside batteries that transports positively charged ions between the two electrode terminals, known as the cathode and the anode.

The company says its electrolyte, Anthro Proteus, has been designed to directly replace the electrolytes used in the popular and widely used lithium-ion batteries that are used as power sources in everything from smartphones to electric vehicles.

But Anthro Proteus is designed to be significantly safer and more durable than current electrolytes, potentially allowing manufacturers to store more energy in their batteries and allowing those batteries to endure far more charging cycles than current models.

And because of the electrolyte's properties, it could give manufacturers much more flexibility in how they design batteries, allowing them to pack more energy into tighter spaces.

Such advantages could result in electric cars that drive farther or smartphones that go longer between charges — or lighter devices that last just as long.

“It’s been really cool to see how our technology solves these existing pain points — and then, once [manufacturers] get their hands on it, say, ‘Hey, what could we do now?’” said David Mackanic, Anthro’s CEO.

The Mechanics of Anthro Proteus

Nearly all electrolytes currently used in lithium-ion batteries are liquid. The advantage of such materials is that when that liquid is injected into the battery cell, it easily spreads everywhere within it, coating the electrodes, said Dan Steingart, the chair of Columbia University’s Earth and Environmental Engineering Department. That’s important, because electric current passes through those points of contact.

But the problem with liquid electrolytes is that they’re highly volatile — damaged or ruptured batteries can overheat or even catch fire. To minimize such dangers, manufacturers limit the amount of energy batteries can store and use thick packaging to hold in the liquid, Steingart said.

To address such concerns, some companies, such as San Jose-based Quantumscape, have been working on so-called solid-state batteries, in which the electrolyte material is in solid form — typically a ceramic — rather than liquid.

Solid electrolytes are less flammable than liquid ones and, at least in theory, safer — although that’s being contested right now, Steingart said.

But it can be difficult to get solid electrolytes to make contact with all of the parts of the electrodes, Steingart said. They can also fracture or crack, and they require battery makers to use a different manufacturing process than they use currently, said Jeffrey Lopez, an assistant professor of chemical and biological engineering at Northwestern University.

Anthro Proteus is a kind of hybrid between the two approaches. It starts off as a liquid and is in that form when it’s injected into a battery cell. That gives it the advantages of traditional electrolytes. It also allows manufacturers to use it without significantly restructuring their manufacturing lines, said Joe Papp, Anthro’s chief technology officer.

But once inside the battery, Anthro Proteus turns into a solid. One of the final steps in making lithium-ion batteries is the formation process, during which manufacturers essentially cure the batteries by applying pressure and temperature, and charging and discharging the cells. Under that same process, Anthro Proteus solidifies into a rubbery polymer material.

Benefits of Solid-State Characteristics

That change of state makes batteries filled with the electrolyte much more stable and durable than traditional lithium-ion cells, Mackanic said.

Once Anthro Proteus solidifies, “It’s kind of like gluing the battery together,” he said. “Everything is locked in place. You get these really dense, structurally solid battery materials.”

With Anthro Proteus, the company is essentially trying to offer the best features of both kinds of electrolytes while fitting into current production systems, said Steingart, who is familiar with the company and Mackanic.

“It’s, I think, a realpolitik approach to thinking about ways of making batteries more solid without giving up all the advantages of a liquid electrolyte,” he said.

Anthro Proteus does seem like it could slot easily into existing production lines, said Lopez, who is also familiar with the company and worked on his Ph.D. in the same lab at Stanford as Mackanic. And the improved safety that the electrolyte promises could give manufacturers the confidence to pack more energy into their cells, he said.

Funding and Future Plans

Anthro has raised $45 million in venture funding to date from investors including Union Square Ventures and Emerson Collective. It has also received about $57 million in grant funding.

That latter amount includes $5.5 million from the California Energy Commission. The company is using that funding to set up a battery manufacturing line at its Alameda headquarters, where it employs about 50 people.

It also includes $24.9 million from the U.S. Department of Energy, which Anthro is using to help build a full-scale electrolyte-manufacturing plant in Louisville, Ky.

The startup is part of a burgeoning battery-development and broader green-energy scene in the Bay Area. But it’s one of the few companies that working on electrolytes, said Brenna Teigler, CEO of the Electrochemistry Foundry, a Hayward-based facility that’s helping local battery startups develop and commercialize their technologies.

Anticipating Future Expansion

Anthro plans to break ground in the fall on its Louisville factory, where it expects to start production in 2028. When that reaches full production by 2029 or 2030, it should be making about 12,000 tons of electrolyte material per year, Mackanic said.

Anthro already has a prospective customer for at least some of that material. In May, it announced a memorandum of understanding with battery maker EnPower — which has a manufacturing plant two hours away in Indianapolis — to develop batteries built around Anthro Proteus.

The initial focus of that effort will be making batteries for drones and larger-scale electronic devices, particularly for the defense sector, Mackanic said.

But once the Louisville plant gets up to full production, Anthro plans to branch out into developing batteries for electric vehicles and home-storage systems, he said.

The challenge that any battery-technology startup faces is that it can take years to commercialize new innovations, and existing industry players aren’t sitting still, said Andreas Breiter, a partner on the Battery Accelerator Team at McKinsey, a consulting firm.

Startups’ technology therefore has to be better than not just today’s technology, but what that technology will be like years down the line, he said.

That said, batteries consist of many components, and none is necessarily more crucial than the others for improving overall performance. And as applications for batteries become increasingly varied, there will demand for batteries with different kinds of properties — some that last longer on a charge, some that charge faster, some that discharge more rapidly, he said.

That leaves plenty of space for new entrants like Anthro to carve out niches in the market, he said.

“This is still a relatively new industry, so there’s still a lot of improvement opportunities,” he said.