This makes great sense! I'd guess this would be (relatively) easily integrated with a standard hybrid system, although the powertrain would be quite expensive (hybrid system PLUS turbocharger system).

I wonder if this would work well with a turbodiesel engine?

Also, I'm a bit confused: why is this not an electric supercharger? I thought the 'turbo' name meant that there was a turbine that spins using the engine exhaust gasses, which drives a compressor that compresses the intake air. This appears to spin using an electric motor instead...