Ms Zheng said the prototype could run up to four times longer than a traditional lithium ion battery and has the potential to be fully biodegradable. The greenphone's bio battery generates electricity using enzymes to catalyse sugar in the drink. As the battery dies out, only water and oxygen are left behind. Unfortunately, Nokia will not be developing the greenphone prototype further in the near future. Ms Zheng told Sky News: "At the time they wanted something to bring out within the next two years and thought my design was too futuristic." But she added that bio batteries are being developed by large electronics companies and may be on the market in the next five years.