They're calling this black sludge "Cambridge crude," and it's really two different types of goo, each holding charged particles suspended in semi-liquid electrolyte, sort of like how quicksand is comprised of sand particles suspended in water. There's anode goo, and there's cathode goo, and when the two goos are separated by a goo-separating membrane, charge moves from one goo over to the other goo, generating current to power your car.
When all the charge has been used up, you can pull over to a goo station, which will suck out your used goo and pump new goo back in. Or, when you get home, you can plug your car into a wall socket and recharge your goo that way.
That could be huge if it turns out to be viable. If you were able to recharge your vehicle to full capacity in the same amount of time it took to pump a tank of gas, then electric cars are no longer just a niche item to make greenies feel better about themselves (remember – they rape Mother Gaia just slightly less than you and they do so with compassion).
Although, still no flying cars, so the future is a ways off.