Can Nikola Motor’s big battery promises be true?

Electric-truck maker Nikola Motor has endured a rollicking stock market entry this month after listing through an unusual reverse merger. The frenzy has been fueled in part by the company’s claims that it will reveal a new kind of battery by the end of this year.

But despite the looming deadline, Nikola appears to still be in the early stages of developing its battery. And even if Nikola succeeds in creating a working version, it could be as much as a decade before manufacturing begins.

Because of the uncertainty, experts are cautious about the company’s claims. Many similar efforts to commercialize new battery technology over the years have yet to bear fruit.

Nikola founder and chairman Trevor Milton promises that his company will be able to produce batteries at a cost of around $70 per kilowatt-hour of storage capacity. That would be a massive improvement over more established vehicle makers such as Tesla and Volkswagen, which are still chasing the goal of producing batteries for $100 per kilowatt-hour.

Price per kilowatt-hour of energy storage is a key factor in the final cost of electric vehicles, and their competitiveness with internal combustion vehicles. Estimates of the battery cost that would make electric passenger cars cheaper to buy and operate than gas-burners range from $100 per kilowatt-hour down to $85 per kilowatt-hour.

Battery development represents a significant expansion of scope for Nikola. The company’s planned flagship product is the Nikola One, a long-haul semi that uses liquid hydrogen, a fuel that doesn’t create carbon emissions and can be produced using renewable energy. Nikola plans to lease the trucks and control much of the hydrogen supply chain, including building its own fueling stations.

The company has yet to sell a single vehicle of any type, but its plans have been enough to attract nearly $1.3 billion in venture funding from sources including European truckmaker CNH Industrial and German manufacturer Bosch.

The pitch has proved even more alluring to public investors. Nikola’s shares rose 136% between the June 4 reverse merger—a maneuver that avoids the lengthy initial public offering process— and June 9, when the company’s market value briefly rose to $30 billion, higher than Ford’s. By late on June 12, the stock was down 21.7% from its peak.

“It is some bold claims that they’ve made,” says Gene Munster of Loup Ventures, an investor focused on electric vehicles. “Now the clock starts ticking, because they have to deliver.”

Building a better battery isn’t easy

Nikola isn’t yet revealing much about how it plans to leapfrog competitors in battery technology. But Milton says the aim is to reveal the battery before the end of this year at an as-yet unscheduled event called Nikola World.

Milton did share a few hints with Fortune.

The technology wasn’t developed by Nikola. Instead, Milton says, “we found some professors who had been working on it for quite some time,” but declined to identify them. He did reveal that the planned battery “has lithium, but it is not a lithium-ion [battery],” and that the design’s aim is to “get rid of the cobalts, nickels, and magnesiums” — the metals that account for much of the cost of existing battery technology.

Based on those details, Matthew McDowell, a battery materials researcher at Georgia Tech, speculates that Nikola may be working on what’s known as a lithium-metal battery. Broadly, the idea is to replace the graphite mesh that stores lithium in today’s lithium-ion batteries with more lithium, increasing energy density by 30% to 40%. That idea is already being aggressively pursued by a large number of companies and researchers, McDowell says.

In contrast, James Frith, an analyst with the research firm Bloomberg New Energy Finance, believes Nikola may be developing lithium-sulfur battery technology. Chris Robinson, an analyst with Lux Research, and Mihri Ozkan, an engineering professor and battery researcher at the University of California at Riverside, also agree that lithium-sulfur is the likely goal, based on the company’s claims.

Lithium-sulfur batteries are lightweight but bulky—a possibly good fit for the large trucks that are the centerpiece of Nikola’s planned product line. The technology was patented in the early 1960s, and broad efforts to commercialize lithium-sulfur batteries have been underway for more than a decade, including by startups like Oxis Energy. Those commercialization efforts have yet to succeed, according to Ozkan, because of challenges including the safety and life span of lithium-sulfur batteries.

It’s unlikely that Nikola is keeping wraps on any radical, previously unknown innovation in battery technology, according to experts in the field.

“Progress in the battery industry doesn’t come from single large breakthroughs, but rather continuous improvements,” says Robinson. “The odds an entirely new chemistry—especially one as close to commercialization as Nikola suggests—would slip past a multibillion-dollar industry are slim to none.”

Whatever the approach, Nikola is likely years from producing a new kind of battery at scale. Despite its very specific cost projections and plans to debut the technology within six months, Nikola is still in the laboratory-testing phase of development.

“In the lab we get a few thousand [charging] cycles, which is much better than lithium-ion,” Milton says, referring to a key measure of a battery’s longevity. “But the real world is much different from the lab…Now you’ve got to make them a lot bigger, [and] you’ve got to abuse them” under varied temperatures, weather, and use conditions.

Experts agree that there is a big difference between the lab and the road. In fact, optimistic promises about battery innovation based on laboratory results are common—but many of those proposed technologies have yet to be commercialized.

“It’s a really complicated process,” says McDowell. “When you’re developing a battery technology, there’s 15 or 20 different metrics you need to hit to have a reliable product. And they’re all intertwined.”

Those metrics include not only performance under varied temperature and weather conditions, but also a battery’s life span, energy density, and the rate at which it loses its charge when not in use.

Frith, of Bloomberg New Energy Finance, estimates that transitioning a new kind of battery from the lab to commercial use takes 10 years, or as little as five once working prototypes are complete. Investors won’t have to wait quite that long to know whether Nikola can eventually fulfill its battery promises, though.

“We’ll know in 6 to 12 months whether [Nikola’s claims] are true or not,” says Munster. In that time frame, he says, the company will need to show it can build a working vehicle using its battery, even if it hasn’t yet reached commercial-scale production.

“It’s not going from the lab to 1% market share. It’s going from the lab to the road where people can literally kick the tires,” says Munster. “And they have to have some evidence that they built it at the right price. That’s the hurdle they need to hit.”

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