Elon Musk had a lot to say on Tesla’s much-ballyhoed “Battery Day.”
The day he said would revolutionize electric transport and get everybody excited.
Well … it didn’t quite live up to expectations, to say the least.
According to Wired, this turned out to be a fat lithium-ion battery called a 4680 — a reference to its diameter, 46 millimeters, and its length, 80 millimeters — that is being produced in-house at Tesla.
To be sure, Tesla’s new battery appears to offer large performance gains in a few key areas, but it was unclear whether Tesla has actually achieved these upgrades or whether this is the projected performance for the finalized battery, Wired reported.
Neither Musk nor Drew Baglino, the senior vice-president of powertrain and engineering at Tesla who shared the stage, offered specific numbers about the new 4680 cell’s actual performance achieved during tests, only relative percentages of improvement compared to existing Tesla batteries.
They claimed to be “unlocking” up to a 54% increase in the range for Tesla vehicles and energy density for its energy products like the Powerwall, Wired reported. (A battery’s energy density describes its capacity to do work given its weight or volume.)
Baglino and Musk also claimed a 56% reduction in the dollars per kilowatt hour compared with Tesla’s existing cells, but did not name a dollar figure.
Battery experts say that $100/kwh is necessary to make electric vehicles cost competitive with gas guzzlers, but it is unclear if Tesla hit this mark since the company doesn’t publish the dollars per kilowatt hours for its existing batteries.
Analysts estimate that Tesla achieved somewhere around US$150 per kilowatt hour last year, which means that it’s new battery may have broken through that barrier, Wired reported.
Baglino said that the company had already produced tens of thousands of batteries at its new production facility down the street — but not a single physical cell made an appearance at the event.
Perhaps there wasn’t an Uber driver available to deliver it?
“I want to stress that this is not just a concept or a rendering. We’re starting to ramp up manufacturing of these cells at our pilot production facility just around the corner,” said Baglino.
Both Musk and Baglino acknowledged that Tesla engineers are still in the process of refining the manufacturing process, so it’s possible that the cells currently coming off the line don’t quite meet this mark.
“We’re still ironing out the kinks,” Baglino said. “It’s super demanding because every atom has its place, if you want to deliver the energy density and the cycle life. We’re confident we can get there, but it will be a lot of work along the way.”
According to The Verge, here is what Musk announced …
The company is moving toward eliminating cobalt in its batteries, it has a new Plaid powertrain for the Model S that could get to speeds of 200 mph, and, a new cathode plant to streamline its battery production.
Nowhere near the automotive revolution promised by the eclectic billionaire.
And, with the new battery technology, Musk has said Tesla will make a US$25,000 car in three years.
Meanwhile, the socially-distanced outdoor event had Musk and other presenters addressing Tesla shareholders in parked cars, who honked their horns to indicate their approval of the speakers’ remarks — like a bizarre drive-in movie.
Tesla currently sources its batteries from Panasonic, and is likely to keep doing so for some time, but moving battery production in house has been on Musk’s to-do list for some time.
Based on the digital mockups shown at the event, the new 4680 cell is a lot different than the lithium-ion cells currently used in Teslas, Wired reported. For starters, it’s big.
The diameter of the cylindrical cell is twice as wide and it is 14% longer than the largest batteries that power Musk’s electric empire today. Altogether, that makes its volume about six times greater than that of the Panasonic 2170 cells used in newer model Teslas.
The upshot of its size is that it increases capacity while reducing the number of cells needed to provide a given amount of power in a battery pack, Wired reported.
According to Baglino, the larger form factor alone was enough to boost the energy by five times, the power by six times, and the range of a car using these batteries by 16%.
Musk has also been teasing the Plaid powertrain for a while, which will be a step above its Ludicrous model. It will have a range between charges of 520 miles, get from 0-60 mph in under two seconds, and a top speed of 200 mph, The Verge reported.
According to media sources, it recently did a 1:30.3 lap time at Laguna Seca Raceway. So it’s quick.
The price is listed on Tesla’s website at US$139,990. Musk had noted in the past that a Plaid trim level would “cost more than our current offerings,” which it does. It will be available in the Model S in late 2021.
Musk said Tesla will build a new cathode plant for its batteries in North America, part of its quest to reduce supply chain costs and simplify cathode production, The Verge reported.
It’s also making improvements to its process that will make cathodes 7% cheaper, and produce zero wastewater. The company also plans to diversify the cathodes it uses, because of low nickel supplies.
According to Car & Driver, the company has retained the rights to its own lithium mine in Nevada and says that state has enough to power all the electric vehicles in the US.
Tesla also said it recycles 100% of its vehicles with third parties. It’s started its own in-house pilot program in Nevada to recycle Tesla products.
The key to Tesla’s battery breakthrough was. according to Musk, a “very esoteric” representation of a tabless battery’s structure, Wired reported.
According to Baglino, the company laser-patterned existing foil current collectors so that they can have dozens of connections to the electrode materials. The result is a current collector that Baglino described as a “shingled spiral” that looks a bit like a curled up, copper-plated armadillo.
“The distance the electron has to travel is much less,” Musk said. “So you actually have a shorter path length in a large, tabless cell then you have in a smaller cell with tabs. So even though the cell is bigger, it actually has a better power-to-weight ratio.”
Researchers at Tesla also significantly altered the chemistry of their electrodes to boost performance, Wired reported.
Tesla is now one of several manufacturers producing silicon-rich anodes, which are meant to supplant the more common graphite anodes used in lithium-ion batteries today.
When a lithium-ion battery is charging, lithium ions flow to the anode, displacing electrons and creating an electric charge. Compared to graphite, silicon can absorb a lot more ions.
According to Wired, Tesla is also working on improvements to its cathode chemistry. Most lithium ion batteries found in electric vehicles today — including Tesla’s — use a cathode made from lithium nickel manganese cobalt oxide, otherwise known as NMC.
But Musk and other manufacturers have indicated their desire to ditch NMC for cathodes that don’t use cobalt, which is one of the most expensive materials in an electrode and is also linked to unethical mining practices in the Democratic Republic of Congo.
The idea has been to use a nickel-rich cathode instead, which is cheaper, lighter, and, depending on how it’s sourced, better for the planet.
Meanwhile, Musk is known for making big promises on aggressive timelines.
Without question, the battery he hyped at the Tesla event is full of promise, but without an actual cell to show off or published performance metrics, it still felt like just a promise.
Now he has to deliver.