March 22, 2007 All is no longer as it seems – the clear flexible plastic in the image is a battery – it is a polymer based rechargeable battery made by Japanese scientists. Drs Hiroyuki Nishide, Hiroaki Konishi and Takeo Suga at Waseda University have designed the battery – which consists of a redox-active organic polymer film around 200 nanometres thick. Nitroxide radical groups are attached, which act as charge carriers. Because of its high radical density, the battery has a high charge/discharge capacity. This is just one of many advantages the ‘organic radical’ battery has over other organic based materials according to the researchers. The power rate performance is strikingly high – it only takes one minute to fully charge the battery and it has a long cycle life, often exceeding 1,000 cycles.
The team made the thin polymer film by a solution-processable method – a soluble polymer with the radical groups attached is “spin-coatedâ€