Nikola Motor’s Bombshell Battery Claim Irks Experts, Who Think Its Secret May Lie In Sulfur

Nikola Motor CEO Trevor Milton seems dead set on challenging Elon Musk’s dominance for audacious transportation ideas, upstaging the Tesla chief’s “Cybertruck” debut with a claim that his own hydrogen and electric vehicle company has a breakthrough battery. Experts suspect Nikola’s secret tech derives from a cell chemistry scores of researchers are also digging into.

Milton, whose Phoenix-based startup intends to start delivering zero-emission semi-trucks in 2021, said last week that Nikola’s battery cell has double the energy density, only 40% of the weight and half the cost of 2170 lithium-ion cells used in Teslas and other consumer-market electric vehicles. He tells Forbes those gains come from eliminating costly metals such as nickel, cobalt and magnesium, use of a “free-standing electrode” and a “whole different type of chemical, with a lithium component.” 

The cell was developed by a specific university lab Nikola was involved with from an early stage and the company “has locked up all the IP,” Milton says. That’s all the company will say for now and public demonstrations won’t happen until the second half of 2020.

“I have a strong conviction that it’s safe to dismiss this out of hand–their claims are ridiculous,” said Sam Jaffe, managing director of Boulder, Colorado-based consulting firm Cairn Energy Research Advisors, which specializes in energy storage technology. “Why would they claim this without waiting until they could publicly reveal what the chemistry is and the university laboratory they are working with? It’s very fishy.”

Sulfur is one possible alternative to current lithium-ion cells, Jaffe said. “I would assume they’re looking at sulfur in the cathode and lithium metal in the anode. Untold hundreds of university and industry labs are working on that. If you get to those, if you can make it work, it would have a significant improvement on current lithium-ion, but nowhere near what they are claiming.”

The pressure to cut carbon emissions from autos has resulted in steady growth in electric vehicle sales, led by Tesla, notably in China, California and Europe, with more hitting the road over the next decade. Battery costs and durability have improved as lithium-ion cell technology matures, but the on-board energy available to propel a vehicle remains far less than for gasoline, on a weight basis. That’s why the longest-range Tesla Model 3 sedan, at 4,072 pounds, only goes 310 miles per charge, while a 3,764-pound BMW 3 sedan cruises 530 miles per fueling, according to Car and Driver. A cell like the one Nikola claims to have would erase that gap–if it exists and can be produced.

IEA Estimated Global Electric Car Sales and Market Share, 2013-18

(For more on Nikola and Trevor Milton, see “Behind New Billionaire Trevor Milton’s $3 Billion Push To Make America Run On Hydrogen” from the September 30, 2019 issue of Forbes magazine.)

“There is a huge dimension of things that need to work well,” says Mike Ramsey, a Detroit-based senior research director for Gartner who tracks auto technology developments.

“An automotive battery has to be inexpensive, it has to last a long time, it has to undertake a huge duty cycle. It has to produce a high amperage output and it has to be able to handle all kinds of environmental conditions, and you have to make sure it doesn’t explode,” he says. “In a lab, in certain circumstances, you probably can produce one that has a lot better performance than what we currently have. But to be able to check all the boxes required to have a battery that does what they say is incredibly hard.” 

Ramsey, like Jaffe, needs persuading. “Until I see it, I just assume they’re full of it.”

Milton says he’s prepared for skepticism. “We’ve never promised something and not delivered,” he says. “I don’t care if they don’t believe it.” 

Lithium-ion batteries are used in modern EVs because of high energy density. Within a rechargeable lithium-ion battery pack, individual cells have three main elements: the cathode (positive electrode), the anode (negative electrode) and a chemical electrolyte between them. Typically, cathodes are made from lithium-cobalt oxide compounds, while anodes use graphite. Electrolytes vary depending on battery type, but tend to be flammable. When the pack charges, cathodes release lithium ions that move through the electrolyte to the anode. They travel back when the battery discharges. 

Among its claims, Nikola says its cell is “environmentally friendly and easy to recycle” and unlike the toxic, expensive elements in lithium-ion cells, the new technology will “have a positive impact on the earth’s resources, landfills and recycling plants.”

The cell is also the first that “removes binder material and current collectors, enabling more energy storage within the cell,” according to the company. 

Sounds great, but can it be done?

Sri Narayan, a professor of chemistry at the University of Southern California, agrees that using sulfur in the cathode could be an option, “but lithium-sulfur chemistry is not mature. It’s evolving, so there are numerous issues that aren’t solved. That’s on the positive electrode side. On the negative electrode side lithium is still the material that’s proposed.”

Binder material is what holds the particles of a battery’s cathode and anode together. “Elimination of binders could potentially improve performance as they are insulating materials,” he says.

“With carbon nanotubes to interconnect the particles, binder materials could be avoided. Conducting polymer materials do not need a binder and can store charge. Therefore, these could be potential candidates for the anode or cathode.” 

Using silicon as an anode material would also provide increased energy density, he says. Other options include an improved alkaline battery chemistry with an air cathode such as the zinc-air battery.

Without more information, it’s simply not possible to offer a more detailed assessment. “It’s not completely unthinkable what they’re saying, and if I knew the specifics of it we can argue whether it’s a viable thing for an electric vehicle or not,” Narayan says.

Near-term production and commercial use, however, are another matter. 

“Brilliant people are out there working their tails off to figure this out,” Jaffe says. “For a company to come in and make a phantom announcement that they’ve made a breakthrough of such ridiculous magnitude, it’s damaging for the industry.”