Salt-Induced Doping and Templating of Laser-Induced Graphene Supercapacitors

Abstract

The use of inexpensive and widely available CO2 lasers to selectively irradiate polymer films and form a graphene foam, termed laser-induced graphene (LIG), has incited significant research attention. The simple and rapid nature of the approach and the high conductivity and porosity of LIG have motivated its widespread application in electrochemical energy storage devices such as batteries and supercapacitors. However, nearly all high-performance LIG-based supercapacitors reported to date are prepared from costly, petroleum-based polyimide (Kapton, PI). Herein, we demonstrate that incorporating microparticles of inexpensive, non-toxic, and widely abundant sodium salts such as NaCl and Na2SO4 into poly­(furfuryl alcohol) (PFA) resins enables the formation of high-performance LIG. The embedded particles aid in carbonization and act as a template for pore formation. While increasing both the carbon yield and surface area of the electrodes, the salt also dopes the LIG formed with S or Cl. The combination of these effects results in a two- to four-order-of-magnitude increase in device areal capacitance, from 8 μF/cm2 for PFA/no salt at 5 mV/s to up to 80 mF/cm2 for some PFA/20% Na2SO4 samples at 0.05 mA/cm2, significantly higher than that of PI-based devices and most other LIG precursors.

Enhanced Antimicrobial Activity of Laser‐Induced Graphene‐Wrapped Trimetal Organic Framework Nanocomposites

“…Here, in situ restacking of LIG layers provided a 2D platform to Tri-MOF clusters for the formation of a layered structure, and wrapping of Tri-MOF clusters with LIG led to the formation of LIG/Tri-MOF sheathed nano architecture. [51][52][53] During the synthesis process, 2-MIM coordinated with metal ions and facilitated the wrapping of Tri-MOF clusters with LIG. [26] However, sonication of the LIG/Tri-MOF composite for 30 min resulted in the unwrapping of the LIG from the Tri-MOF clusters.…”