October 5, 2014

WSJ 5th Oct – There is no Moore’s law for batteries. That is, while the computing power of microchips doubles every 18 months, the capacity of the batteries on which ever more of our gadgets depend exhibits no such exponential growth. In a good year, the capacity of the best batteries in our mobile phones, tablets and notebook computers—and increasingly, in our cars and household gadgets—increases just a few percent.

It turns out that storing energy safely and reliably is hard in a way that miniaturizing circuits is not. A pound of gasoline contains more than 20 times as much energy as a pound of lithium-ion batteries. And then there’s the expense: The battery pack in a Tesla Model S costs approximately $30,000.…