In an industrial estate south of the historic university city of Cambridge, researchers at a company called Echion Technologies are looking for the ideal formula for fast-charging vehicle batteries.
Given that many governments have an ultimate goal of net-zero carbon emissions, such an invention would be very timely.
Electric cars already have long-distance capabilities — a 322-kilometre range is not unusual — but many need hours of being plugged in to achieve a full charge.
Being able to achieve this in the less that an hour would make cross-country journeys more feasible, therefore making an electric vehicle a more enticing prospect to consumers.
Faster charging may also improve the productivity of electric buses or delivery vans by allowing more time on the road and less time plugged into the power supply.
Batteries that can be charged rapidly may also make it easier to use electric trains without installing expensive electrification infrastructure, such as overhead line equipment.
The work at Echion Technologies’ headquarters in south-east England centres on a chemical element that many people have never heard of: niobium.
Despite its low profile, niobium has been on the radar as a potential material for lithium ion battery anodes — the material in a lithium ion battery that receives lithium ions — since the 1980s.
Numerous firms around the world are investigating its use, so this metal, sometimes found in stainless steel, could play a significant role in the transition to electric transport.
“The work that was done prior was a starting point. It hasn’t been optimised as a commercial material,” says Benjamin Ting, Echion Technologies’ chief commercial officer
“It was the focus of Echion to come up with the optimum material to be used as a battery anode suitable for use in mass markets.”
Like much research and development, these efforts are nothing if not painstaking: over the past few years, Echion Technologies has screened close to 1,000 niobium-based anode candidate materials and selected “a very narrow proportion”.
Research and development staff — who altogether make up about two thirds of the company’s 30-plus headcount — produce powders containing mixtures of chemical substances in varying proportions, which are synthesised in a furnace.
The powder is then mixed into inks and tested for how well they coat foil to become electrodes.
The resulting electrodes are tested in dozens of small coin-like batteries, each outwardly similar to batteries found in, say, television remote controls or bank card readers.
“Our results at coin level have prompted a number of large cell manufacturers to begin development on commercial formats using our material,” Mr Ting said.
Combination of key factors
Optimising battery performance involves juggling multiple variables. Key among them are the charge rate, the energy density, the power density, the operating temperature, the number of charge and discharge cycles a battery can last for, plus its safety and sustainability.
Optimising the charge rate and the energy density is of particular significance, because faster-charging batteries often have a lower energy density.
“Often, if you try to optimise for one, you’re going to see a trade off in others,” Mr Ting, an Australian chartered engineer, said. “We say we offer the best balance.”
Creating something that is viable as a mass-produced product is a “big step”, from finding a material that works well in the lab. But the company is quietly confident that it has developed an anode material that could find appeal in the marketplace.
“We don’t say we’re game changers, but we like to think we’re going to make a difference to a number of big industries,” Mr Ting says. “We’re pragmatic, which gives confidence to those who want to commit to any new battery material, as it’s a long-term investment and commitment to make.”
The company says its XNO material offers, among other things, a long cycle life, safe operations and the ability to work at a range of temperatures.
It is said to retain 70 per cent of its energy output even at temperatures of –30°C and is also resilient at high temperatures, which may be especially useful in regions such as the Middle East.
Major manufacturers are now producing cells using Echion Technologies’ material and production is being scaled up “at the thousand-tonne scale”.
Keeping up momentum
Prof Poul Norby, of the Department of Energy Conversion and Storage at the Technical University of Denmark, says there has already been “a lot of progress” with fast-charging technology, which he describes as being important “to really move the vehicles over to electric”.
“If you look back just a few years, the cars charged at maybe 50 or 100 kilowatt [kW]. Now it’s become more common to charge at 150kW,” he says.
Ultimately, there may be numerous types of niobium-containing anode materials that make an impact commercially. There is certainly no lack of interest among battery companies.
Indeed, just a few miles north of Cambridge lies another firm, Nyobolt, which is also working on fast-charging technology using niobium.
Further afield, the electronics giant Toshiba and two partners announced last year that they were working on developing lithium-ion batteries using niobium titanium oxide as the anode material, while firms in China, Israel and, in particular the US, are also focusing on niobium.
Many other companies are developing fast-charging batteries that rely on different chemical elements.
While Echion Technologies’ niobium-based anode material could find its way into car batteries, the company says its use in batteries for delivery vans, buses, trains or even mining vehicles is more likely.
“A passenger EV may not be the best fit, but a delivery van, a UPS van that may have multiple drivers and short breaks, these vehicles are in sight,” Mr Ting says.
“Fast charging is going to be important for buses because it’s not ideal that you have buses sitting around for six hours a day. You want to be able to utilise them.”
Prof Norby says that improving charging speeds for buses and other large vehicles may allow the use of smaller batteries that could be charged quickly at the end of a bus route, potentially saving money and weight.
This may entail installing additional charging stations than are needed when buses are charged overnight at central depots, so the ideal solution depends on the balance of “advantages and disadvantages”.
Mr Ting says shrinking battery size reduces the quantity of battery material needed, which cuts the environmental impact of production, highlighting the numerous potential benefits of fast-charging technology.
“We’re quite hopeful there will be segments that put fast charging as the selling point,” he says.