PEDOT:PSS‐CNT Composite Particles Overcome Contact Resistances in Slurry Electrodes for Flow‐Electrode Capacitive Deionization

Activated carbon (AC) particles constitute the current material of choice concerning preparation flow electrodes for flow-electrode capacitive deionization (FCDI). They are inexpensive, mass-producible, highly conductive, and exhibit a large specific surface area ion adsorption. However, despite recent advances modification AC slurries, their density, hydrophobicity still major challenges regarding particle aggregation, sedimentation, pumpability, restricting load to approximately 25 wt.%. Since volume fraction directly correlates chance contact, which dictates charge transfer hence degree electrode utilization, development AC-based slurries seems stagnate. This study addresses these by investigating poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)-based suspensions as an alternative conventional carbon-based electrodes. The corresponding conductive hydrogel feature softness, internal porosity, low hydrophilicity, mass-specific salt adsorption capacity that exceeds up ten times. FCDI experiments can reveal that, contrary AC, inherent properties PEDOT:PSS-based simplify slurry process enable circulation at significantly higher fractions. These results suggest promising candidate overcome percolation contact-related state-of-the-art slurries.