Those eggs you might have had for breakfast? They're not just food -- they may be the key to longer-running batteries in your devices. Scientists at MIT and Tsinghua University have developed a nanoparticle battery electrode whose egg-like design is built to last. Their invention, which houses a shape-changing aluminum "yolk" in a titanium dioxide cell, can go through charging cycles without degrading like the graphite electrodes in conventional power packs. That could improve not only the overall longevity of the battery, but also its capacity and maximum power. You'd have gadgets that not only hold out for longer between charges, but don't need to be replaced quite so often under heavy use.