Improving Charge/Discharge Properties of Radical Polymer Electrodes Influenced Strongly by Current Collector/Carbon Fiber Interface

Abstract

Charge/discharge processes of organic radical batteries based on the radical polymer's redox reaction are largely influenced by carbon fibers consisting in the composite electrodes to help electron transfer. To find the optimal structure of the composite electrodes, the dominant electron transfer processes were determined by ac impedance measurement of the composite electrodes. A strong correlation between the overall electron transfer resistance of the composite electrodes and the materials of the current collector suggests that the electric conduction to the current collector through the contact resistance should be crucial. It was also confirmed that the charge/discharge performance of the composite electrode was related to the overall electron transfer resistance of the composite electrode. These results indicated that the charge/discharge performance of the radical battery was dominated by the interfacial electron transfer processes at the current collector/carbon fiber interface and that the rate performance would be much improved by suitably designing the interfacial structure.

Organic Electrode Materials for Rechargeable Lithium Batteries

“…[ 95 , 101 ] Still, the electrode structure did not seem to be optimized in these studies in view of the impractically high content of conductive CF (80%), moderate utilization of the active material (70%), and capacity reduction over short time period (less than two days of cycling). [ 102,103 ] Since the fi rst two processes are generally smooth as proved by numerous electrode systems, researches have focused on the last three factors toward optimization of the electrode confi guration. The electron transfer reaction within a radical polymer electrode composite, as illustrated in Figure 8 , is controlled by fi ve processes including (1) interfacial charge transfer from the current collector to the conductive carbon, (2) electric conduction in the carbon network, (3) heterogeneous charge transfer at the carbon/polymer interface, (4) electron hopping between radical sites within the bulk polymer layer, and (5) diffusion of electrolyte counter anions throughout the composite.…”

Radical Polymer‐Wrapped SWNTs at a Molecular Level: High‐Rate Redox Mediation Through a Percolation Network for a Transparent Charge‐Storage Material

“…[10][11][12][13][14] We have been developing the organic radical battery, [10][11][12][13][14][15][16][17][18][19][20] utilizing a series of synthesized polymers containing redox-active organic radicals fenced by bulky alkyl groups. [15][16][17][18] Typically poly(2,2,6,6-tetramethylpiperidine-1-oxy-4-yl methacrylate) (PTMA) was employed as the organic cathode-active pendant group.…”

Melt‐Polymerization of TEMPO Methacrylates with Nano Carbons Enables Superior Battery Materials

“…[30] Incorporation of conductive agentsw as performed afterwards, either by physicalb lending with cross-linked PTMA or by mixing solubilized polymer with conductive carbon. [32] Finally,n or eports deal so far with in situ synthesis of carbon-incorporated PTMA-basedb attery materials. It should be mentioned that carbon has ad ual role in such composite electrodes:i te nhances the charge collection efficiencyb ut also absorbst he soluble species and thus retardst he slow dissolution of the active material dissolution effect.…”