► First vacuum cleaners, now an electric car?
► Set to use new battery tech from Sakti3
► Plenty of challenges, but plenty of potential
After CAR revealed in May 2016 that Dyson was secretly working on its own electric car, founder and inventor James Dyson announced to company employees that the rumours are true, and that it's due to launch in 2020.
Mr. Dyson told employees in a company-wide message that the fast 'adoption of oxymoronically designated 'clean diesels'' spurred him on to make his own change in the electric car market.
Dyson's EV team is more than 400-strong, according to the company message, and the inventor is investing £2bn in further development.
Mr. Dyson also said in the message: 'Some years ago, observing that automotive firms weren't changing their spots, I committed the company to develop new battery technologies.'
See below for the full message in a tweet from the Dyson company's main Twitter account:
Dyson electric car: the CAR scoop from May 2016
This announcement gives Britain an answer to the EVs in development from heavyweight Silicon Valley giants, Google and Apple. And the Dyson car could have double the energy density and range of today’s EVs, thanks to a breakthrough solid-state battery.
News of Dyson’s EV was accidentally leaked in the government’s recent National Infrastructure Delivery Plan 2016-2021 which stated: ‘Dyson [is] to develop a new battery electric vehicle at their headquarters in Malmesbury, Wiltshire… This will secure £174m of investment in the area, creating over 500 jobs, mostly in engineering.’
The revelation was quickly redacted in favour of: ‘The government is providing a grant up to £16m to Dyson to support research and development for battery technology at their site in Malmesbury.’
Dyson, famed for its cyclonic separation vacuum cleaners and in the news with its £299 Supersonic hairdryer, is geared up for an EV push thanks to its $90m acquisition of battery company Sakti3. The start-up, launched out of the University of Michigan by Professor Ann Marie Sastry, claims to have developed solid-state lithium-ion batteries producing over 400Wh/kg energy density.
That’s almost double the punch of Tesla’s Panasonic cells – reckoned to be the industry leader at around 240Wh/kg – effectively doubling an EV’s range while potentially slashing costs to $100 (£69) per kilowatt-hour, the tipping point at which EVs start to rival petrol/diesel-powered cars on costs.
Trouble is, battery history is littered with glorious failures such as Canadian company Avestor, which went bankrupt after the solid-state lithium-ion batteries it sold AT&T started exploding inside U-Verse home entertainment boxes. So why do Sastry and Sakti3 (Sakti is Sanskrit for ‘power’ and three is lithium’s periodic number) think they have cracked it, where others failed?
Today’s lithium-ion batteries are typically packed out with gels or liquids that don’t store any energy; Sastry’s dream was to discover a ‘solid’ conductive material diffuse enough to let lithium-ions pass back and forth from anode to cathode, discharghing and charging the battery.
So a decade ago, Sastry and her colleagues wrote simulation software to identify combinations of materials and structures around lithium that would result in high energy batteries, that also could be mass-produced affordably. It’s no use having the best energy density or greatest number of cycles if they are prohibitively expensive to manufacture.
In prototype assembly of the micro-thin layers that build up the batteries, Sastry’s team modified secondhand equipment used to make printed foil crisp packets. In reality the same, proven, thin-film deposition process employed to make flat panel displays and photovoltaic solar cells will layer micro-thin films of cathode followed by the current collector, then the interlayer anode and so on, all within a vacuum. Once assembled the resulting cells are charged and ready for testing.
Scaling up battery manufacturing from the lab test bench to series production is the big challenge, says Peter Wilson, Bath University’s professor of electronic and systems engineering. Dyson faces another sizeable challenge: increasing the size of its advanced digital electric motors from vacuum cleaners to powering a car. But if Dyson cracks it, the UK could have its very own Tesla rival.
The innovations that will drive Dyson’s breakthrough
1) Solid-state battery
Although based on lithium-ion tech, the pressurised liquid electrolyte is replaced by a thin layer of non-flammable material that acts as both the separator (keeping positive and negative electrodes from coming into contact) and the electrolyte (allowing ion transfer to happen).
2) Safer than liquid
Lithium-ion batteries typically run at 35°C, demanding complex cooling for EVs, and both Tesla and GM’s batteries have suffered fires. To extend their service life, the batteries should never be fully charged or discharged. Solid-state batteries don’t suffer from these problems.
3) Clever motors
Dyson’s digital ‘switched reluctance’ motors benefit from excellent packaging and mechanical design, says Wilson. They offer good cooling and thermal performance – which is key – while aerodynamically efficient rotors, that are quiet and cool, minimise losses.
4) A question of scale
With brushless motors already 90+% efficient there isn’t a lot of headroom for Dyson’s digital motor. It will have inertia and thermal challenges if scaled up to car size, on top of losses generated by electric fields in the rotor. Using a series of laminations reduces these losses.
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