Charging/discharging kinetics of poly(3,4-ethylenedioxythiophene) in 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)imide ionic liquid under galvanostatic conditions

Freestanding flexible polymer films based on bridging of two EDOT units with functionalized chains for use in long-term-stable supercapacitors

Freestanding flexible films were prepared by cross-linking two EDOT unit with fictionalized flexible chains, the application of these films in supercapacitors showed excellent cycling life.

Stable Deep Doping of Vapor-Phase Polymerized Poly(3,4-ethylenedioxythiophene)/Ionic Liquid Supercapacitors

Liquid-solution polymerization and vapor-phase polymerization (VPP) have been used to manufacture a series of chloride- and tosylate-doped poly(3,4-ethylenedioxythiophene) (PEDOT) carbon paper electrodes. The electrochemistry, specific capacitance, and specific charge were determined for single electrodes in 1-ethyl-3-methylimidazolium dicyanamide (emim dca) ionic liquid electrolyte. VPP-PEDOT exhibits outstanding properties with a specific capacitance higher than 300 F g(-1) , the highest value reported for a PEDOT-based conducting polymer, and doping levels as high as 0.7 charges per monomer were achieved. Furthermore, symmetric PEDOT supercapacitor cells with the emim dca electrolyte exhibited a high specific capacitance (76.4 F g(-1) ) and high specific energy (19.8 Wh kg(-1) ). A Ragone plot shows that the VPP-PEDOT cells combine the high specific power of conventional ("pure") capacitors with the high specific energy of batteries, a highly sought-after target for energy storage.

Biomimetic dual sensing-actuators based on conducting polymers. Galvanostatic theoretical model for actuators sensing temperature

A theoretical model is proposed for the quantitative description of the chronopotentiometric (E-t) responses, under galvanostatic control, of either conducting polymer films or dual sensing-actuating devices. Assuming that the reaction occurs by extraction, or injection, of n consecutive electrons from, or to, a polymer chain the material moves through n consecutive oxidation or reduction states. Stair functions are obtained describing either potential or consumed electrical energy evolutions as a function of both, driving (current) and environmental (temperature, electrolyte concentration...) variables. The current quantifies the actuation of any electrochemical device (charge/discharge of batteries, movement rate, and position of muscles): the stair functions are dual actuating-sensing functions. A good agreement exists between theoretical and experimental results from either polypyrrole films or artificial muscles at different temperatures. Only two connecting wires include, at any time, sensing (potential) and working (current) information of any dual device.

Polymer films on electrodes: investigation of ion transport at poly(3,4-ethylenedioxythiophene) films by scanning electrochemical microscopy

Electropolymerization, morphology characterization, and ion transport of poly(3,4-ethylenedioxythiophene) (PEDOT) films doped with different counterions (chloride, ferrocyanide (FCN), and poly(p-styrenesulfonate) (PSS-)) on a platinum electrode were investigated using scanning electrochemical microscopy (SECM) during both potential step (chronocoulometric) and cyclic voltammetric scans. An ultramicroelectrode (UME) tip was positioned close to the surface of a PEDOT-modified substrate electrode, and the responses of both electrodes to a substrate potential step or linear sweep were monitored simultaneously. Chloride or ferrocyanide (FCN) ejection during PEDOT reduction was shown to be a function of the reduction potential. The nature of the cation in the bulk solution was not found to be important in the kinetics of ion transport in PEDOT+/FCN- films. Direct evidence for the incorporation of cations of Ru(NH3)6(3+/2+) in a PEDOT film during its reduction was also obtained by SECM measurements. The adsorption of Ru(NH3)6(3+) in fully oxidized PEDOT+/PSS- films was observed and attributed to ion exchange between the Na+ co-ion of PSS- and Ru(NH3)6(3+) in the bulk solution.