You're right. Pure lithium-ion batteries definitely are available. Besides price, one of the reasons they haven't been adopted is they don't have great performance over temperature. By using supercapacitors, we are able to make it a lot more immune to temperature.
We really approached the problem from the opposite direction. We started with supercapacitors and asked ourselves how we could make a reliable system around them. Huge current surges at the levels needed for starting a car are hugely destructive for batteries. It's almost as bad as just shorting them with a wrench. We decided that capacitors were fundamentally better suited for what a car battery does.
We really approached the problem from the opposite direction. We started with supercapacitors and asked ourselves how we could make a reliable system around them. Huge current surges at the levels needed for starting a car are hugely destructive for batteries. It's almost as bad as just shorting them with a wrench. We decided that capacitors were fundamentally better suited for what a car battery does.