The impact of laser-scribing carbon-based supercapacitor electrodes

• DOI: 10.1016/j.apsadv.2022.100262
• Publication Date: 2022-06-06T09:40:52Z
• Authors: J.M. Baptista; G. Gaspar; K.G.U. Wijayantha; K. Lobato
• Keywords: Horizontal scan rate

In highly porous carbon electrodes, a large fraction of pores can be inaccessible to the electrolyte, which translates into lower specific capacitances. This is accentuated at high current densities. To circumvent this, channels opened enhance ionic diffusion. this work, were created using pulsed laser. Nine sets laser-scribing parameters (pulse fluence and spot spacing) applied on two carbon-based supercapacitor electrodes: K-bar hand-coated electrodes ("K") screen-printed ("SP"). Profilometry scanning electron microscopy revealed that, before laser-scribing, latter already had several holes trenches, whilst former compact films. Electrochemical measurements in Na2SO4 indicate improvements rate capability laser-scribed SP namely an up 50% reduction energy density decreases as power densities increase. For K slope Ragone plot only decreased by ca. 20% best set conditions. However, for both negative trade-off observed: laser processed seem have capacitance. might caused entrapment debris laser-drilled holes, could lead overestimation active mass. Moreover, X-ray Photoelectron Spectroscopy analysis suggests that may also explained decrease oxygen functionalities its impact electrodes' wettability. On other hand, tested organic electrolyte (tetrabutylammonium perchlorate acetonitrile), capacitance 2 A/g was 66% higher 13 Wh/kg achieved even 2.8 kW/kg.