Fabrication of a Practical and Polymer-Rich Organic Radical Polymer Electrode and its Rate Dependence

• Published in: Macromolecular rapid communications. 2008-10, Vol.29 (20), p.1635-1639
• Main Authors: Suguro, Masahiro, Iwasa, Shigeyuki, Nakahara, Kentaro
• Format: Article
• Language: English
• Subjects: Applied sciences; charge transfer; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; electrochemistry; electrode; Exact sciences and technology; lithium ion; Organic polymers; organic radical polymer; Physicochemistry of polymers; Polymers with particular properties; Preparation, kinetics, thermodynamics, mechanism and catalysts; rechargeable battery; TEMPO
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.200800406

A practical and polymer‐rich organic radical cathode that contains 80 wt.‐% poly(4‐vinyloxy‐2,2,6,6‐tetramethylpiperidine‐N‐oxyl) (PTVE) and 15 wt.‐% vapor‐grown carbon fiber (VGCF) has been fabricated. The PTVE/VGCF composite electrode shows a reversible redox peak at 3.56 V (vs Li/Li+) in cyclic voltammetry. A coin‐type cell with the PTVE/VGCF composite electrode as the cathode and lithium metal as the anode has also been fabricated and used for charge/discharge measurements. When the cell was discharged at 0.3 mA · cm−2 (1 C), a capacity of 104 mAh · g−1, which is 77% of PTVE's theoretical capacity (135 mAh · g−1), was obtained. When it was discharged at 9.0 mA · cm−2 (30 C), its capacity was 52% of the capacity it had when it was discharged at 0.3 mA · cm−2 (1 C). Even when discharged at 24 mA · cm−2 (80 C), it surprisingly had 32% of the capacity it had when discharged at 0.3 mA · cm−2. The observed rate dependence shows that the polymer‐rich electrode could discharge over 50% of the cell capacity in two minutes and over 30% within one minute.