Though a long way from being commercialized, the new battery developed by Sony generates electricity using glucose, which is chemically broken down with enzymes. Apparently, you can power small electronics endlessly through a supply of glucose solution which you pour into the battery (I'm sure airline security will love that). While glucose-powered batteries are more environmentally friendly because they don't emit carbon dioxide, at this stage of development, they're not yet very practical. The output of a single glucose cell is 50 milliwatts; in the photo above, four cells are linked together to generate sufficient power to operate an MP3 player.

Via The Nikkei Weekly.