As carmakers race to develop electric battery-powered cars, they are constantly vying for anything that will give them the edge over rivals.
After announcing that it expected to produce its “solid-state” batteries as early as 2027, Toyota on Tuesday unveiled ambitions to halve the size and cost of power units for its electric vehicles to make them safer and let them charge faster.
But despite the Japanese car group’s optimism, this holy-grail battery technology has long eluded the industry.
Smaller, lighter, safer and faster
From the most expensive Tesla to the cheapest Fiat, electric vehicles currently on the market use batteries that have liquid lithium-ion electrolytes.
The electrolyte allows the current to pass through the battery between the two electrodes — the anode and the cathode — generating the power.
But EVs that run on liquid batteries have several well-documented shortfalls, such as being very heavy and taking much longer to recharge than petrol cars take to refuel. They can also catch fire, especially if batteries overheat.
So-called solid-state battery technology, which uses a solid electrolyte, has the potential to address these concerns.
The batteries can hold much more power, making them smaller without compromising on range. They are able to charge very quickly without getting hot, making them much safer.
Toyota said it expected its EV powered by solid-state batteries to have a range of 1,200km — more than twice the range of its current EV — and a charging time of 10 minutes or less.
Where the anode and cathode meet
Despite years of global investment the technology is still nascent.
Setting an exact timeline is therefore difficult.
Toyota says it believes it can commercialise the technology into a vehicle by 2027. Although this is just four years away, it replaces a previous target of 2025 which the carmaker originally set in 2017 and then reaffirmed in 2021, when it said it thought it could use the batteries in a hybrid model.
“Top management . . . has asked me if we can really do it [by 2027],” Keiji Kaita, Toyota’s top battery expert and president of its research and development centre for carbon neutrality, said on Tuesday. “But I am presenting them with evidence while we are working on it.”
Yet despite his confidence, battery researchers have witnessed timetables pushed back again and again.
“A lot of developers have been saying ‘in five years’ time for the past 10 years,” said Victoria Hugill, a battery research analyst at consultancy Rho Motion.
Experts also expect semi-solid batteries to reach commercial use sooner than fully solid ones.
The main challenge for solid-state battery developers is getting solid contact between the electrodes — where the lithium-ions are stored — and the electrolytes that facilitate the movement between them, she added.
Shirley Meng, a battery professor at the University of Chicago, told a Financial Times conference that solid-state batteries also needed to operate at a certain pressure “to function at its optimum level”, which is still a technological challenge for manufacturers. “This needs to be resolved before the technology can really take off,” she added.
Looking for the technological edge
Toyota has long been resistant to embracing fully electric cars in the way that its largest rivals such as VW and Ford have.
It argues that they are too expensive for developing markets, that charging will be difficult in countries with poor electricity grids, and that using the world’s limited lithium resources in hybrids will lower overall emissions faster.
However solid-state technology, which is far more expensive to produce than traditional battery systems and still requires power to recharge, does not appear to address all of these concerns.
As competition to develop solid-state batteries heats up, getting to market first would certainly help Toyota gain an edge in a segment where it has been slower than rivals to roll out models.
The Japanese group argues that its 20-year experience with hybrid batteries will help it develop better EVs. However, its major EV rollout is not expected to begin until the middle of this decade.
Despite the fanfare around its announcement, Toyota executives themselves insist they are not gambling only on solid-state batteries and expect further technological breakthroughs to be made with liquid lithium-ion batteries.
“We don’t actually view solid-state batteries as the ultimate solution,” said Toyota’s chief technology officer Hiroki Nakajima.
Solid-state battery competition revs up
Perhaps unsurprisingly, many carmakers are investing in the technology, hoping to steal a march in electric vehicles. BMW has said it will begin testing solid-state cells this year, with a development vehicle tentatively expected before 2025. However, it does not realistically expect mainstream manufacturing until the end of the decade.
Nissan has already unveiled a prototype battery facility in Japan as it works to produce a vehicle using the technology in 2028, a year after Toyota’s latest target. The company said it expected to reduce battery costs to $75 per kilowatt hour during 2028 and to $65/kWh later, which would make its EVs cost the same as petrol-powered vehicles.
Toyota’s Kaita added that the company would aim to resolve the issue of high cost by simplifying the number of processes required to make battery materials.
Start-ups such as QuantumScape, which is backed by Bill Gates and Volkswagen, have also been developing solid-state battery technology.
In 2015 vacuum maker Dyson bought Sakti3, a solid-state start-up, which it believed would help it break into the car industry. Delays to the technology were among the reasons why in 2019 it pulled plans to make a vehicle.
Yet the company carried on developing its battery system and is building a factory in Singapore that is expected to produce some form of non-liquid batteries from 2025, suggesting that it has already made a significant breakthrough.
Showcasing its ambitions
Since the appointment of a new president in April, Toyota has sought to revamp its image as an EV laggard, following pressure from shareholders to explain how it plans to stay ahead in the global race for battery-powered vehicles.
In June the Japanese carmaker took reporters on a rare tour of its technical centre near Mount Fuji, where it showcased not only its ambitions for next-generation solid-state and liquid lithium-ion batteries, but also new manufacturing methods that will make it simpler and faster to produce electric vehicles.
“We are not very good at promoting ourselves and because we’re excessively cautious, people only realise that we were working [on a certain technology] once the product is completed,” Kaita said, revealing that the company had already made early breakthroughs in durability issues of solid-state batteries three years ago.
Executives have customarily revealed few details about its “technological breakthrough”, with Nakajima saying only that the company had found a promising material for solid-state batteries.
This has led some shareholders to question Toyota’s progress, saying that a lack of detail on the specific “breakthrough” did not leave them convinced it could achieve the goal by 2027, and asking whether the announcement was merely intended to placate investor concerns about its overall EV approach.
Yet Toyota remains set on the date. “2027 will be a challenge for us,” said Nakajima, “but it’s not that we don’t have any basis [for the date].”
Additional reporting by Eri Sugiura and Harry Dempsey in London