What is... a solid-state battery?
Dyson wants to make an electric vehicle, with a solidstate battery at the core of its £2.5 billion R&D project. Here’s why it may not be easy to hit the 2020 deadline
Goodbye internal combustion, hello electric – that’s the refrain from car manufacturers, many of which are promising to shift to emission-less vehicles, while governments galore have outlined plans to ban petrol and diesel within three decades. Vacuum genius Sir James Dyson has hailed that bandwagon, pledging £2.5 billion in R&D investment and 400 engineers to develop a UK edition.
A billion pounds of that cash is directed at the battery alone, with Dyson working on solidstate models designed to last from Cornwall to Scotland. The British engineering firm hopes to have cars on the road by 2020, racing rival Toyota with the same roadmap to use solid-state batteries in electric vehicles within three years. Here’s why both firms are looking at solid-state technologies – and what challenges may see them slamming the brakes.
The battery in your phone or camera is likely lithium-ion, which is light, charges quickly and rechargeable. It’s made up of solid lithium electrodes set in a chemical electrolyte. Solid-state batteries ditch that liquid electrolyte in favour of a solid conductive material such as a polymer or ceramic.
Why go solid?
Such batteries would offer a higher capacity in a smaller package, charge faster and last longer, and wouldn’t go up in flames under pressure – a key selling point. It’s one thing to have your Samsung Galaxy Note 7 get all toasty and explode, it’s another thing when that happens to the family car. Plus, using a non-flammable version means car makers can ditch cooling systems and make space for a larger battery. Solid-state batteries are also likely to last longer, not only in terms of capacity but in charge cycle life. Smartphone battery life fades every time you charge and discharge. While we happily replace smartphones every two years, cars need to last a wee bit longer.
What’s the holdup?
It’s not been easy to find a solid-state material that conducts well enough to do the job. Swiss lab EMPA has had success with amide-borohydride, MIT has suggested sulphide-based solids, and other researchers have even focused on using air as an electrolyte rather than solids. Another potential is glass. John Goodenough, a researcher at the University of Texas at Austin, has successfully used glass electrolytes in place of liquid – and he’s got cred in the battery world, as he’s the one who made lithium-ion batteries work at the University of Oxford in the 1980s.
Why not just build Goodenough’s batteries?
What works in the lab doesn’t always translate to commercial products. Solid-state batteries not only need to work, they need to be manufactured at scale and at low enough cost. In the meantime, another battery technology could sweep in and win the race. Elon Musk’s Tesla is reportedly working on a new lithium-ion battery technology, hiring top researcher Jeff Dahn. Solid state is just one horse in the race.