Electroactive polymers have long been investigated as prospective charge-storage materials for electrochemical capacitors and rechargeable batteries. Conventional synthetic routes to such polymers have relied on electrodeposition, typically as thin films at planar substrates, or solution-phase methods that yield precipitates, which can be difficult to incorporate into composite-electrode structures. Recently, the Reynolds group at Georgia Tech has developed a family of solution-processable electroactive polymers, whose solubility characteristics are tuned via side-chain derivatization of ProDOT and EDOT structures [1,2]. We exploit the tailorable solubility of these polymers to facilitate their incorporation into macroscopically thick carbon nanotube/nanofiber papers. By distributing the polymer as a thin coating on a 3D carbon-based current collector, the inherent high-rate character of the polymer is maintained while the capacitance/capacity per geometric footprint is amplified by factors of ten or greater compared to analogous thin films. The chemical nature of these polymers can also be varied to achieve charge-storage functionality in either aqueous or nonaqueous electrolytes, which expands the range of electrochemical device configurations that will benefit from these advanced electrode materials. To demonstrate the technological promise of polymer–carbon electrode architectures, we perform electrochemical tests in three-electrode cells and two-terminal devices, assessing such critical characteristics as rate-dependent capacitance/capacity, self-discharge, and cycle life.

1. Ponder Jr., J. F.; Österholm, A. M.; Reynolds, J. R. “Designing a Soluble PEDOT Analogue without Surfactants or Dispersants,” Macromolecules 49, 2106 (2016).

2. Österholm, A. M.; Ponder Jr., J. F.; Kerszulis, J. A.; Reynolds, J. R., “Solution Processed PEDOT Analogues in Electrochemical Supercapacitors,” ACS Appl. Mater. Interfaces 8, 13492 (2016).