Shigeyuki Iwasa

Effect of Ethylene Oxide Structures in TEMPO Polymers on High-Rate Discharge Properties

Introduction We have proposed an “organic radical battery” (ORB) in which stable organic radicals such as a nitroxide radical are applied to the electrode active material of a rechargeable battery. In the ORB an organic radical polymer poly(4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl) (PTMA) bearing a 2,2,6,6tetramethylpiperidine-N-oxyl (TEMPO) radical was first used as a cathode active material. We reported that an Allaminated film packaged battery using PTMA might be suitable for high-power applications. We very recently synthesized poly(4-vinyloxy-2,2,6,6tetramethylpiperidine-N-oxyl) (PTVE) so as to improve the capacity of the ORB. The theoretical capacity of PTVE (135 mAh/g) is far higher than that of PTMA (111 mAh/g). 3 In this work, with a view to improving highspeed charge and high-output discharge properties of the ORB using modified PTVE copolymer, we have modified PTVE with ethylene oxide. We describe here the charge/discharge characteristics of a Li/copolymerized PTVE coin-type cell.