The battery in every gasoline or diesel vehicle today looks pretty much the same: It’s a black box with two silver posts for the cables. Sure, there can be some minor differences inside, but automobile batteries haven’t changed much for around a century.
Things are going to be very different as the electric vehicle era ramps up. Billions are being spent to improve battery safety, durability, power capabilities and charging times.
The battery is changing from being a cheaply replaced regular wear item into one of the most crucial parts of the vehicle.
It will be the battery that determines how far and how fast an EV can go on a charge. The battery will affect the sticker price when a vehicle is new and its value on the used-car market.
Unlike today’s batteries, EV batteries will come in different shapes and sizes and have chemistries that vary, depending on the battery manufacturer, the brand of vehicle and the vehicle’s mission.
A sports car, for example, would likely have a battery pack designed to deliver a lot of power quickly. A sedan, on the other hand, would likely have an energy-dense pack made for long-range driving.
“If I look at the history and evolution of things, we’re still doing incremental improvements,” said Richard LeCain, head of cell and process development at Britishvolt, a U.K. battery company about two years from producing its first cells for automakers. “There won’t be a moonshot in batteries that is the equivalent of going from a ground to putting people on the moon. There will be quite a bit going on in the chemistry realm and improvement there that continues to drive efficiencies and cost reductions of cells. That’s still the path.”
Toyota Motor Corp. and Volkswagen Group are two automakers looking to improve today’s lithium ion battery to ensure the technology’s performance characteristics and costs match the vehicle it is being used in.
Automakers are placing big bets on solid-state batteries, which replace the liquid electrolyte with a solid structure that enables ions to move much faster between the anode and cathode. This helps increase energy density and reduce charging times, and it lowers the risk of overheating.
Solid-state batteries could be the next big development — if chemists can solve several major problems. For example, the batteries form growths called dendrites that reduce efficiency and shorten life. They are also more expensive to produce.
“There is going to be a role for different chemistries,” said Matt Renna, Volkswagen Group of America’s vice president for e-mobility and innovation. “You are seeing the inclusion of [lithium iron phosphate] batteries and [nickel manganese cobalt] in our lineup. It’s not like these are replacement technologies, the same way that the four-cylinder engine didn’t overtake the eight-cylinder. Both can coexist for different customers and needs. We see the same for battery chemistry and cell types.”
Researchers at universities, startups and elsewhere are testing new chemistries in an effort to produce better batteries for lower cost. Last week, for example, the University of California, San Diego revealed promising progress on a solid-state lithium ion battery that uses a silicon anode instead of one made of graphite, which is commonly used in today’s lithium ion batteries. Silicon anodes, according to the university, can be as much as 10 times more energy dense than graphite anodes, and they allow batteries to recharge faster at lower temperatures.
But any battery that is used in an automobile has to be capable of long life, safety and reliability under the extreme temperature conditions cars often encounter. And they must be able to withstand constant vibrations from the road and remain safe in severe collisions.
Toyota has been pushing hard to have solid-state batteries ready for mass production by mid-decade. It is testing the batteries in vehicles in Japan.
At the same time, it is working to improve older battery technologies, such as nickel metal hydride, the same chemistry that debuted in the original Prius hybrid two decades ago.
The Japanese-market Toyota Aqua hatchback hybrid uses the automaker’s latest generation of bipolar nickel metal batteries. “Compared to the batteries used in the previous generation of the Aqua, the output density has been doubled, giving the car a powerful acceleration sensation,” Masahiko Maeda, Toyota’s chief technology officer, told investors in September during the automaker’s briefing on batteries and carbon neutrality.
Britishvolt’s LeCain sees EV batteries improving in the same way that the internal combustion engine improved over more than a century: incrementally. He said he believes there are plenty of gains to be made in making lithium ion batteries better. The company is working on technology that reduces the weight and size of the pack.
“Right now we’re trying to take parts out, going from cell to chassis, using hard-cased prismatic cells that bear some of the weight and structure of the vehicle,” LeCain said.
Britishvolt’s first cells for the auto industry will be lithium ion, but the company is also investing in solid-state batteries. And unlike many other battery companies, its leadership team includes two auto industry veterans, both of whom have extensive powertrain backgrounds:
- Joe Bakaj, former Ford of Europe vice president of product development. He is Britishvolt’s vice chairman.
- Graham Hoare, former chairman of Ford of Britain. He is the battery-maker’s president of global operations.
Although global automakers and battery companies are investing billions over the next nine years toward cell development, it’s not clear whether a battery will ever hold as much energy as a gallon of gasoline or be as convenient to use.
A Chevrolet Silverado pickup, for example, has a 24-gallon fuel tank that can be refilled at most stations in about three minutes. Driven on the highway, the truck will get 21 mpg and travel around 504 miles before it needs more fuel. A full fuel tank in the Silverado weighs 146.4 pounds.
To get a driving range of 300 or more miles, the battery pack in electric vehicles has to be very large. A Tesla Model 3 with the long-range battery pack contains 4,410 cells and weighs more than 1,200 pounds; the EPA-estimated range is 358 miles. Even a compact Chevrolet Bolt’s battery pack, with its range of 259 miles, weighs around 960 pounds.
And then there’s the matter of charging times. For the roughly 80 percent of EV drivers who charge at home and don’t exceed their vehicle’s range, those long waits aren’t usually a problem. But for those who need to use public chargers, wait times can be long, anywhere from 15 minutes to an hour, once plugged in, to get reasonable range.
“Were combustion cars viable in 1950? Absolutely. People got to and from work every day. Are they better today than they were in 1950? Absolutely,” said Renna. “You’ve had billions of R&D dollars and engineers working on making them better every day. Using that analogy, I think electric cars are viable today, and solid-state batteries have the potential to make them more viable in the future.”