Rechargeable, energy-dense bio-batteries running on sugar might be powering our electronic gadgets in as little as three years, according to a US team of scientists. The battery, created by the group of Percival Zhang, an associate professor of biological systems engineering at Virginia Tech, can convert all the potential chemical energy stored in a sugar into electricity.The prototype is similar in size to a typical AA battery and has an energy storage density of 596 amp hours per kilogram – roughly one order of magnitude greater than a smartphone’s lithium-ion battery. This means that the battery could last at least...