(167i) ‘One-Pot’ Multi-Scale Templating of Interdigitated Bi-Modal Porous Carbon Supercapacitors

Porous carbons show promise as electrodes for electrochemical double layer capacitors (EDLCs) or supercapacitors. Related efforts have focused on simultaneously maximizing accessible surface area while tuning molecular structure and charge transport. This work highlights the ‘one-pot’ nanocasting of carbons bearing a unique interdigitated bimodal three-dimensionally ordered mesopore (ib3DOm) topology constructed of thin (ca. 5 nm) but robust pore walls. This structure is achieved by the co-assembly of size-tunable (ca. 10-50 nm) silica nanoparticles with carbon molecular precursors followed by polymerization, pyrolysis and template sacrifice. Whereas we previously identified a narrow parametric envelope for achieving ib3DOm structures in film form[1], we will show that ib3DOm powder formation can be achieved over an expanded range of carbon precursor concentrations and silica nanoparticle solids contents. This expanded pseudo phase space establishes the versatility of this facile powder templating approach, and offers additional flexibility for exploiting interface-mediated synthesis-structure-function relations for tuning carbon microstructure [2]. Specifically, we will demonstrate how both carbon precursor concentration and silica nanoparticle solids content can be used to tailor the carbon allotrope distribution, namely sp² carbon content, within the carbon walls. This facile templating strategy enables tuning of surface areas to as high as 1330 m²/g, pore volumes to as high as 5.8 cm³/g, and sp² hybridized carbon content as high as 80%, with remarkable performance as electrodes for supercapacitors with specific capacitance of 275 F/g in H₂SO₄ electrolyte and 284 F/g in KOH electrolyte at 1 A/g, and retention as high as 90%.

References

[1] Z. Tian, M.A. Snyder, Langmuir, 30 (2014) 12411-12420.

[2] M. A. Snyder, MRS Bulletin, 41(9) (2016) 683-688.