If you’re even slightly interested in electric cars, chances are you’ve heard that solid state batteries are the future, coming to save us from range anxiety and the slow decline in power retention that current lithium-ion batteries face.
But that might not be what really happens if senior drivetrain and battery engineers from Audi are correct in their predictions.
While it seems like some brands are holding back releasing a stable of EVs before the advent of mass production solid state batteries, senior engineers at the launch of the new Audi Q6 e-tron say it’s unlikely solid state batteries will be feasible as the basis of an electric car future.
But rather than canning the idea of solid state batteries altogether, it seems that Audi is taking the approach that it’s too early to write off any one method of battery tech development.
As a brief refresher, most electric cars in Australia feature a lithium nickel manganese and cobalt (Li-NMC, or alternatively NCM) battery chemistry, which perform well in terms of charging and efficiency, but are relatively expensive and can slowly lose their ability to hold charge over time.
There is also a rise in the use of lithium-iron-phosphate (LFP) batteries, which are cheaper and don’t degrade as much over time, though they’re also heavier and less efficient. This tech is most commonly found in BYD’s Blade batteries and entry-level Teslas.
Solid state batteries are lighter, use fewer materials, provide a longer range and are less dangerous, though their development is proving slow and they’re certainly not going to be cheap.
According to Audi battery development engineer Johannes Gehrmann, the physical precision required to manufacture solid state batteries means it’s unlikely they’re going to become the prevailing force in providing power to electric vehicles for at least the foreseeable future.
While he said it’s becoming increasingly difficult to find the next ‘breakthrough’ in battery tech, Audi isn’t putting all its eggs into the solid state basket.
While the tech, when employed perfectly, does provide plenty of advantages, it’s incredibly expensive and difficult to achieve on a large scale. One reason Gehrmann provided is that a solid state battery has the potential to expand very slightly with repeated high energy [use?] – not something that’s really acceptable when even a millimetre makes a difference in engineering.
It’s not that Audi doesn’t believe in a future for solid state, Gehrmann said the costs of proper engineering make sense for high-end models, and Audi has plenty of those. But the wider Volkswagen Group and rivals like Toyota or Hyundai Motor Group may end up going with another tech for their mass production models.
Despite VW currently running a program with its battery company PowerCo to determine the viability of solid state, Audi is apparently looking into ways to use LFP batteries in a more efficient way.
LFP batteries are currently used in some of the cheaper EVs on the market, and are particularly popular with Chinese brands, but if Audi is looking into the tech, it’s possible there’s more to be found in terms of their development.
