When pushed into the smallest of cracks, water can be used in unexpected ways. A new battery design that relies on tiny amounts of water confined within layers of clay could eventually offer sustainable power in places as extreme as Mars.
Vasily Artemov at the Swiss Federal Institute of Technology and his colleagues built the battery with components similar to those of conventional batteries, including two electrodes, one with a negative and one with a positive charge. But instead of making these electrodes out of metal, they used the…