Integrating Solution-Processable Conducting Polymers in Carbon Fiber Paper: Scalable 3D Electrodes for Redox-Based Supercapacitors

Nanoscale coatings of a solution-processable conducting polymer, 3,4-propylenedioxythiophene–dimethyl-3,4-propylenedioxythiophene (ProDOT-dimethyl-ProDOT, PDMP), are incorporated within a macroscale carbon fiber paper (CFP) via a scalable deposition protocol to generate a three-dimensional multifunctional electrode architecture (PDMP@CFP). Polymer loading is controlled by the concentration of the deposition solution, reaching up to 39 wt % PDMP loading without significantly obstructing the void structure of the CFP, which is critical for high-rate charge storage and delivery. We demonstrate that anion-based redox reactions of PDMP increase the areal capacity of PDMP@CFP by a factor of 33 over unmodified CFP. Hot-pressing multiple PDMP@CFP sheets together reduces the large void volume of the CFP and further enhances area- and volume-normalized capacitance by factors of 2.5× and 6.8× versus the non-hot-pressed counterpart, respectively. The mechanical flexibility inherent to paper affords the possibility of energy storage and pulse power for wearable applications.