>The result of this is a flexible, stretchable battery with an areal capacity of 50 milliamps per square centimeter, which the team says is 10 to 20 times greater than that of a typical lithium-ion battery. All up, the team says the device can provide five to 10 times more <i>power</i> than a typical lithium-ion battery of the same size.<p>Inaccurate title: the Zn/AgO battery has up to ten times the spatial <i>power</i> density of lithium-ion, which is useful but hardly new, being exceeded by most supercapacitors. It does not, however, have ten times the <i>energy</i> density, which is a much more difficult bar to reach.<p>It probably has a good energy density, as do all silver-zinc batteries, but there's no indication here that the energy density is dramatically higher than when these batteries were used on the Apollo missions in the '60s. They're just flexible now (which is nice).