Radical Polymer Batteries: Towards High-power, Safe and Flexible Devices
Radical polymers are emerging class of electro-active materials useful for various kinds of wet-type organic-based devices. We have synthesized a series of aliphatic polymers bearing organic robust radicals, such as nitroxide and phenoxyl radicals, in a high density as pendant groups per repeating unit. Characterized by an ultimate population of unpaired electrons and very fast electron self-exchange reaction among radical sites, the radical polymers allow efficient “redox-driven” electron transport throughout the polymer layer.The high electron-exchange reactivity of radical polymer electrodes provides surprisingly high current density beyond 100 mA/cm2for rapid charge-storage in rechargeable batteries. Challenges and our strategy related to energy-related devices/applications will be discussed through a bendable battery with burst-power, a photovoltaic cell based on efficient charge-separation, and a hydrogen-carrier utilizing a reversible hydrogenation of such new polymers.
Hiroyuki Nishide is a Professor at Department of Applied Chemistry, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan. He received his PhD in 1975, and has been visiting researcher at Free University Berlin and Polytechnic University New York. He has conducted research in the field of syntheses and applications of functional polymers, recently focusing on the organic polymers for rechargeable batteries and photovoltaic cells. He has published more than 500 journal articles, and is Past-President of the Society of Polymer Science, Japan, of the Federation of Asian Polymer Societies, and of Japan Union of Chemical Scienceand Technology.