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

Abstract

Abstract 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. magnified image