A new type of battery invented in Japan, in the University of Waseda. This is a flexible rechargeable battery, based on polymers. The development of this type of battery was conditioned by the permanently developing industry of portable devices, which become smaller and smaller each year.
Researches on this device have been conducted for several years, but the scientists, working on this battery are Drs. Hiroyuki Nishide, Hiroaki Konishi and Takeo Suga, all of them from the Waseda University, are considered to improve the technology. Their development is based on a redox-active polymer film, which is about 400 nanometers thick. The charge carriers of this battery are the Nitroxide radical groups. Due to a high radical density these thin batteries have a high level of charging and discharging.
According to Dr. Nishide the high charge and discharge capacity of their development is one of many advantages it has over other organic materials, as the power of the organic materials is limited to the amount of charge they get. Dr. Nishide also mentioned that it took only one minute to charge a pfilm polymer battery and that it's life cycle could be over 1000 charges.
However, there are also drawbacks in this development. For example some organic radical polymers are soluble in electrolyte solutions. This results in discharging the battery. The polymer, though, should be soluble, so that the spin-coating would be possible.
The Japanese scientistshave overcome this problem by photocrosslinking, though. This made the polymer more stable and stronger from the mechanical point of view.
Prof. Peter Skabara, from the University of Strathclyde, was impressed by the high stability of the material. The polymer-based production of the battery was also something Dr. Skabara mentioned, while describing this invention.
In his opinion this film battery will make all technologies based on organic devices will highly benefit from this film battery.
Among devices, which potentially could need a flexible battery Dr. Nishide mainly mentioned small memory cards with integrated circuit. He said that within the next three years such cards would benefit from using this invention.
Dr. Nishide added that in the future the battery could be also used in devices, requiring a higher power capability more than high-energy density, such as batteries in different electronic devices and/or in electric vehicles with motor drive assistance.