One-Step Fabrication of Ice-Templated Pure Polypyrrole Nanoparticle Hydrogels for High-Rate Supercapacitors

Abstract

Conducting polymer hydrogels with high conductivity, excellent electroactivity, and good mechanical strength are desirable for the design of highperformance energy storage devices. However, they suffer from the issue of low porosity, which hinders electrolyte diffusion and leads to poor rate performance. In this work, we developed a one-step, in situ chemical polymerization approach to fabricate a porous pure polypyrrole hydrogel (PPH) with a desirable nanostructure via an ice-templating strategy. This simple synthetic approach offers the PPH tunable porosity, ultrahigh conductivity, and good mechanical strength. Owing to these notable advantages, functioning as a supercapacitor electrode, PPH displays a high specific capacitance of 265 F g −1 (1961 mF cm −2 ) at 1.35 A g −1 (10 mA cm −2 ) and maintains 85% capacitance retention even up to 67.6 A g −1 (500 mA cm −2 ). We also found that PPH without an ice-templated nanostructure possesses poor rate capability due to slow and blocked electrolyte diffusion because of the less-porous nanostructure. This facile, ice-templated strategy to structurally design a porous nanostructure for high-rate performance opens up the possibility for advanced energy storage applications.

An Ultrafast, High‐Loading, and Durable Poly(p‐aminoazobenzene)/Reduced Graphene Oxide Composite Electrode for Supercapacitors

“…[ 10,52 ] The porous composite nanostructure with proper redox‐active polymer distribution can promote electron transfer and electrolyte diffusion, realizing large specific capacitance and excellent rate performance. [ 13,26,53 ]…”

“…[10,52] The porous composite nanostructure with proper redox-active polymer distribution can promote electron transfer and electrolyte diffusion, realizing large specific capacitance and excellent rate performance. [13,26,53] In PRH composite, self-assembled graphene sheets form a porous conductive matrix (Figure 5b), facilitating the electron transport between highly homogeneous PPAAB and the RGO substrate and improving ion diffusion in the electrode. Thus, PPAAB can significantly contribute to high capacitance and achieve excellent rate capability.…”

Single vacancy-defect endohedral metallofullerene-superhalogens: molecular topology and nonlinear optical responses of Na@C59[9-4]([8-5])-AlX4 (X = Cl, Br) systems

“…55 The proposed single vacancy-defect endohedral metallofullerenesuperhalogen registered also a notable optical nonlinearity response compared to a series of triangular nanorings, by incorporating B-/N doped phenalenyl (B/NPLY) into cycloparaphenylene (B n N 3Àn -CPLY 3 (n = 0, 1, 2, 3)). 56 It is found that the b tot values of the supramolecular complexes are between 1.17 Â 10 3 and 2.44 Â 10 4 a.u. for B 3 -CPLY 3 @C60, B 2 N-CPLY 3 @C60, CPLY 3 @C60 and N 3 -CPLY 3 @C60, compared to 3.8 Â 10 4 and 6.44 Â 10 6 a.u.…”

A Polyelectrolyte Colloidal Brush Based on Cellulose: Perspectives for Future Applications

“…The morphology and porous structure of the electrode have a more significant impact on the electrochemical performance at higher rates. The gravimetric specific capacitance of the as-obtained CNF-PAA/PPy electrodes was found to be higher than that of other porous hydrogel electrodes with PPy reported in the literature, such as crosslinked PAAm filled with carboxymethylcellulose (CMC)/PPy (~140 F/g at 0.5 A/g) [73], a carboxylated CNF/PPy film electrode (~180 F/g at 0.5 A/g) [74], a CMC-PANI/carbon nanotube film electrode (348.8 F/g at 0.5 A/g) [75], and a porous, pure polypyrrole hydrogel prepared via the ice-templating method (265 F/g at 1.35 A/g) [76]. This comparison demonstrates the possible practical interest in electrodes based on colloid brushes.…”