Not really. According to the article, they have an energy density of 110 J/cm^3, or 30.5 Wh/L. Li-ion easily hits 400 Wh/L, with some already going to the 800s.

Not really. According to the article, they have an energy density of 110 J/cm^3, or 30.5 Wh/L. Li-ion easily hits 400 Wh/L, with some already going to the 800s. Traditional lead-acid car batteries already hit 50-100 Wh/L. The weight story is probably going to be similar. Capacitors like this are useful for short-term energy storage like regenerative braking, not as primary power store.