Cool, but not terribly useful yet for the things that really need progress in batteries: "Battery "breakthroughs" need to state power and energy density (not t

Cool, but not terribly useful yet for the things that really need progress in batteries: "Battery "breakthroughs" need to state power and energy density (not the same thing), plus how long they last. " https://twitter.com/elonmusk/status/585185843649716225 https://twitter.com/elonmusk/status/585185843649716225 "[the] cells only carry 40 watts of electricity per kilogram compared to lithium's 100 to 206 W/kg power density." http://www.engadget.com/2015/04/06/stanfords-battery-charges-in-one-minute/ http://www.engadget.com/2015/04/06/stanfords-battery-charges... They could be a nice replacement for lead-acid though, if they turn out to be stable.