Polypyrrole (PPy) is a promising pseudo-capacitive material for the electrodes of electrochemical capacitors. However, its poor cycling stability, caused by structural pulverization and gradual loss of counter ions during working cycles, greatly hinders its practicability. In this presentation I will talk about a two-prong strategy that can effectively stabilize PPy films, i.e., to deposit films on functionalized partial-exfoliated graphite (FEG) substrates and to use β-naphthalene sulfonate anions (NS-) as dopants. The treated PPy electrode achieved a remarkably stable performance with more than 97% capacitance remained after cycling between -0.8 and 0 V vs. SCE for 10000 cycles. Moreover, an asymmetric pseudocapacitor device using the stabilized PPy film as anode also retained 97% of the initial capacitance after 10000 cycles, which is an exceptional value reported for PPy based supercapacitors. The superior stability of PPy electrode can be attributed to two factors: 1) the flexible nature of FEG substrate alleviates large volumetric deformation of PPy and 2) the presence of immobile NS- dopants locks the counter ions during prolonged working cycles.

Manipulate the chemical composition and substrate nature to push the cycling stability limit of polypyrrole

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.