New Scientist: A BATTERY able to match the output of those used in cellphones from 1/20th of their electrode area may have you dreaming of more talk time. But putting it in your pocket would be a bad idea – it’s full of molten metal. Instead, its inventors hope it will provide much-needed storage capacity for electricity grids. Grid-scale batteries would boost efficiency by allowing solar energy to be used at night, for example, or excess power from a nuclear plant to be stored for …