ORION TOWNSHIP, Mich. — Before General Motors recalled the entire fleet of its most popular electric car because of fire dangers, before her factory was stilled, assembly line worker Carol McConkey stood in the middle of a teeming factory floor and marveled at how seamlessly the Chevrolet Bolt is manufactured.
“It does a lot of it by itself,” she said, describing the automation-heavy process at a GM plant that has gone from building gasoline-powered cars to making electric vehicles — the first such GM plant, which was soon followed by a second, a 30-minute drive down Interstate 75. “To me, it’s just a battery we plug in.”
But there is no mistaking its significance. “It’s the heart of the car,” McConkey said one day this past summer.
Little did she know that soon, the same section of the car she works on would garner worldwide attention for another reason: exploding lithium-ion batteries. She and hundreds of other workers were sent home to wait out an extended assembly line closure.
The crisis involving the Chevrolet Bolt was a painful reminder for the auto industry that despite treating the electric vehicle era as essentially inevitable — a technical fait accompli — significant obstacles to manufacturing the cars, and especially their batteries, continue to threaten that future.
“It’s a terrible thing that has happened,” Tim Grewe, GM’s general director for electrification strategy and cell engineering, said in an interview in September.
It’s the kind of disruption GM can ill afford as it aims to scale up its production of electric vehicles to 1 million units per year by 2025. The company wants to have a global lineup of 30 EVs by that year. And it plans to shift production away from gasoline-powered cars entirely in the next decade and a half.
Carmakers including Volkswagen, Mercedes-Benz and Ford also have announced plans to go all or mostly electric — chasing ambitions similar to GM’s deadline of 2035.
Today, electric cars — plug-in hybrids, battery-powered vehicles and hydrogen-fuel-cell vehicles — make up less than 5 percent of U.S. new-vehicle sales. But policymakers and automakers hope that by 2030, EVs will make up at least 40 percent of U.S. new-car sales. That would be a critical development in the nation’s strategy for reducing greenhouse gas emissions.
The Environmental Protection Agency announced stricter fuel-efficiency standards this month aimed at propelling the nation closer to that goal by 2026, estimating that the new standard will result in electric vehicles gaining about one-fifth of market share by then.
But first, automakers have to show they can manufacture safe and reliable cars — at scale.
“I don’t want to minimize this point, but it also lets us build confidence that we’re going to be transparent, we’re going to take action,” Grewe said.
Why batteries explode
Late last summer, Chevy Bolt owners received a notice from GM: They were not to park their cars within 50 feet of other vehicles. They shouldn’t charge their cars overnight. Fully charged vehicles, GM said, should not be kept in garages.
The recall of the Bolt covered all of the roughly 141,000 units GM had ever built. The company identified the issue as dual defects that led battery materials to make contact with one another and the components to combust spontaneously.
It’s a danger that comes directly from the core challenge of creating electric-vehicle batteries: the competition to pack more and more energy into them.
Car buyers want their electric cars to mirror the convenience of gasoline-powered vehicles, with about 400 miles of range so they can minimize visits to charging stations or plug-ins at home — even if long road trips represent only a sliver of their driving.
That has carmakers in a 21st-century space race to pack as much energy density as possible into their battery cells, maximizing range and performance.
Even as automakers seek to phase out gasoline engines altogether, high-voltage car batteries remain in their early stages of mass production. Many manufacturers are experimenting with new technologies and battery chemistries. While they do so, they are discovering defects — some of which can prove catastrophic.
Late in 2020, a Tesla Model S fire in a San Francisco Bay area residential garage blew the metal garage doors off and spread from one Tesla to another, causing more than $1 million in damage. Instances of fire with no apparent external cause have been documented in at least five Tesla Model S vehicles.
The explosion of an electric car battery can release a massive amount of energy — and the resulting fire can burn for hours, stretching longer and registering hotter than a fire in a car with an internal-combustion engine.
“Battery fires can take up to 24 hours to extinguish,” according to an emergency response guide for the Model S on Tesla’s website. “Consider allowing the battery to burn while protecting exposures.”
GM’s recall, despite its scale and significance to the company, arose from a dozen isolated instances of fire with no external cause. It was a worst-case scenario for the company, which has partnered with an experienced battery maker, South Korea-based LG, to power its electric fleet. GM says LG has instituted new controls to ensure that the fiasco doesn’t happen again. LG, which has made batteries for the Bolt’s entire run, is reimbursing GM for nearly $2 billion in costs associated with the recall.
An electric-vehicle fire can erupt from an electrical short within a single cell — a cylinder or pouch that stores energy to be consumed by the car. A car’s battery pack consists of hundreds or even thousands of cells, which might look to the untrained eye like AA batteries or laptop batteries. The cells carry a charge because of interactions between the highly reactive materials inside them.
Inside the cell, there are three main components: the cathode, or positively charged electrode that stores lithium; the anode, or negatively charged electrode that stores lithium; and a highly flammable electrolyte, which helps lithium ions travel through the cell. As the lithium ions go from one side to another — through charging or discharging — electrons are released to an external circuit, powering the car.
In the middle of the cell, a porous physical separator “acts as an electrical barrier,” allowing the “selective transport” of lithium ions and preventing the anode and cathode from touching, said Jeff Sakamoto, a professor of mechanical engineering and materials science at the University of Michigan College of Engineering. When those components make contact, the consequences can be extreme.
“Both surfaces are electrically conductive,” Sakamoto said. If they touch, “then they short-circuit.”
When that happens, it’s cause for concern but not yet a catastrophe.
In the densely packed cell, a short circuit leads to the release of heat. A large release of heat from a cell can ignite another, and the combined heat can ignite others in a chain reaction known as “thermal runaway.”
In GM’s case, “cooling pillows” surround the pouch-shaped cells to prevent too much heat from being released between them. But they’re not meant to defend against thermal events so far outside normal operating conditions.
“If there’s enough heat it creates, it starts to boil the electrolyte,” Sakamoto said, adding that a puncture in the seal can lead to ignition. “So now you have a recipe for combustion when you have heat, you have a combustible liquid and then some kind of puncture to the cell or packaging — now you have exposure to the air, oxygen.”
GM says there were two defects in Chevy Bolt batteries that probably aided the spread of heat and the sudden release of energy: a torn anode tab and a folded separator. Essentially, there was no longer a reliable barrier preventing the cathode and anode materials from interacting.
“The battery explodes,” Sakamoto said. “The adjacent cells explode, too.”
GM has been hit hardest by fire concerns — but Audi and Hyundai also have recalled EVs over fire risks.
As GM addresses the issues with the Bolt, it has shut down the factory here. And the future of the Bolt, the first realization of GM’s vision for the coming decade, has been thrust into uncertainty.
A fight for raw materials
Before they are able to install the batteries, GM, Tesla and their battery suppliers have to solve another challenging task: obtaining the raw materials to make them.
It’s a problem likely to grow even more difficult in the years to come.
The raw materials used in electric cars are heavily concentrated in only a few regions of the world.
According to an International Energy Agency report, a conventional car uses about 75 pounds of two minerals — copper and manganese. By comparison, an electric car uses more than 440 pounds of minerals, including cobalt, lithium, nickel and graphite.
The report noted that about 70 percent of cobalt comes from the Democratic Republic of Congo and that about 60 percent of rare earth elements, needed for EV motors, are sourced in China. The majority of lithium — the core ingredient in batteries — is obtained in Australia, China and Chile, but China controls most of the world’s supply via its refining businesses. Getting new mines online can take 15 years or longer.
“One of the constraints on the success and pace in the electric-vehicle business will be the supply chain — the development of raw materials and supplies,” said Keith Phillips, president of Piedmont Lithium, which previously struck a deal with Tesla to produce certain battery materials in North Carolina. “I think the fundamental view … is that it won’t be very hard for them to sell electric vehicles, but it might be very challenging for them to make the electric vehicles.”
As companies push 2025 and 2030 deadlines to shift much of their production to electric cars, he said, “there’s a very low likelihood the world can supply enough lithium to make that happen.”
GM acknowledges the challenge.
“Categorically, you’re making all of this huge investment in the material supply,” Grewe said. “Let’s say we hit 2035: You’ve got to convert all that investment” into usable material for the battery.
The U.S. government says the market for batteries is expected to grow five to 10 times its current size over the next decade. Some estimates say the amount of lithium produced must quadruple by 2030 to meet the demand.
“China is the largest global EV market and dominates the supply chain for the manufacture of lithium-ion batteries, including the processing of minerals and raw materials,” says a federal report issued in June. “China relies on massive incentives to support domestic EV manufacturing, retail-level subsidies to create demand for domestic products, and a battery certification program to limit market access for foreign products.”
Tesla Chief Financial Officer Zachary Kirkhorn said on the company’s recent earnings call that the appetite for electric vehicles has grown significantly, creating short-term bottlenecks.
“There appears to just be quite a profound awakening of the desirability for electric vehicles,” he said. “And, I mean, to be totally frank, it’s caught us a little bit off guard.”
Kirkhorn said Tesla has seen a rise in prices for raw battery materials such as cobalt and nickel. The company is weathering the increases through a combination of existing contracts and cost controls, he said, but he expects more cost increases “outside of our control.”
As automakers seek breakthroughs that could power an electric future, lithium ion might not win out.
Sakamoto, the University of Michigan professor — who also is the chief technology officer for the solid-state battery company Zakuro — said he thinks incremental improvements in lithium-ion technology will plateau. Solid-state batteries have solid electrolytes that are not combustible, maximizing capacity and significantly reducing the fire risk.
That would address a core concern: the ability to make larger and larger battery packs with more energy density without compromising vehicle performance by adding weight. But many companies, including GM, are in the early stages of exploring solid-state, and it will take significant time for the technology to reach parity with lithium-ion.
“Two things: It’s the simultaneous improvement in performance and improvement in safety,” Sakamoto said. “If one can make a battery that has those two criteria satisfied, then one can supplant lithium-ion.”
On the factory floor
The plant here in Orion Township is a testament to GM’s electric future — and to the things that can go wrong. Since the closure, which took place in August, there has been hope that the plant will fully reopen; GM now says it will be closed through February. The company said it has decommissioned old equipment for internal-combustion engines at the plant, rendering the facility capable of making only electric and autonomous vehicles.
“GM is in the initial stages of considering the business case for a potential future investment at several locations, including the Orion Township area,” GM manufacturing spokesman Tom Wickham said. “We are not going to speculate or disclose the details of the projects under consideration.”
The energy of the factory floor this past summer, before the shutdown, suggested a recognition that EVs were coming but an unease about what it might mean for workers.
Near the battery installation area, Joel Newsom, team leader of a chassis “marriage line,” bonded a Bolt together with four bolts.
In his free time, Newsom likes to race trucks, specifically his Chevrolet Colorado with a “big block,” shorthand for a type of larger-displacement engine. He has few qualms about GM’s strategy.
“GM is preaching the future for us; we can’t always base it on fossil fuels,” he said.
But he’s not so certain he’d partake.
“For me, it doesn’t fit for what my family does,” he said. “If I lived in the city and I didn’t have far to go and I can just plug it in, it would work out good for me. For a daily driver just to drive around, it wouldn’t be terrible.”
With the Orion plant, GM believes it has proved that the shift to electric vehicles is possible. It can take an existing workforce and train it in new skills while making use of millions of square feet of repurposed factory space and much of its existing machinery to build cars the way it always has.
The plant’s hourly employees — usually more than 1,000 when the facility is fully staffed — have been laid off temporarily, GM said. Those workers are receiving benefits in accordance with their union-negotiated contracts. That means they are receiving unemployment and supplemental pay translating to about 75 to 80 percent of their usual pay, according to GM figures first reported by the Detroit Free Press.
While the plant shutdown continues through February, the longer-term question for workers is how many will be needed for GM’s shift to electric vehicles. Union leaders expressed confidence that the shift won’t mean fewer jobs, at least at GM — but acknowledged the challenge for the industry.
“There’s less physical parts that have to be manufactured to go into this vehicle,” said David Michael, spokesman for the plant’s United Auto Workers chapter, Local 5960. “If you take away a muffler and a catalytic converter and all the things, what do you replace it with? We know technology is getting smaller, more compact, and it’s less than it used to be.”
“The traditional labor concern is always fewer jobs: fewer American jobs because a lot of our parts come from many places around the globe,” he added.
At the end of the assembly line last summer, where gasoline-powered cars once roared to life, Kim Fuhr stood with an electric-vehicle charger in hand.
Fuhr doesn’t have to handle gasoline or deal with the exhaust fumes that preceded her work on the Bolt.
She plugs the charging cable into the car for 30 seconds, gives herself five seconds to remove it, and ensures that the car has 21 percent of its possible juice. It’s a highly repetitive process that might occur 262 times over the course of a nine-hour shift — that day’s production output.
“I’m in [a] retirement home now,” joked Fuhr, a nearly 25-year veteran of General Motors.