As reported by Bloomberg, Tesla has acquired the innovative energy storage company Maxwell Technologies for $218 Million. The move is a direct departure from Tesla’s current energy storage requirements; instead of relying on lithium battery technology, this acquisition could signal a change to capacitor technology.
The key selling point of capacitors, either of the super- or ultra- variety, is the much shorter charge and discharge rates. Where a supercapacitor can be used to weld metal by simply shorting the terminals (don’t do that, by the way), battery technology hasn’t yet caught up. You can only charge batteries at a specific rate, and you can only discharge them at a specific rate. The acquisition of an ultracapacitor manufacturer opens the possibility of these powerhouses finding their way into electric vehicles.
While there is a single problem with super- and ultra-capacitors — the sheer volume and the fact that a module of ultracaps will hold much less energy than a module of batteries of the same size — the best guess is that Tesla won’t be replacing all their batteries with caps in the short-term. Analysts think that future Teslas may feature a ‘co-battery’ of sorts, allowing for fast charging and discharging through a series of ultracapacitors, with the main energy storage in the car still being the lithium battery modules. This will be especially useful for regenerative braking, as slowing down a three thousand pound vehicle produces a lot of energy, and Tesla’s current battery technology can’t soak all of it up.