Laser induced incorporation of CNTs in graphene electrodes improves flexibility and conductivity

Abstract

Laser processing of nanocarbon films emerges as the preferred technique to prepare carbon-based electrodes. A great effort focuses on exploiting this fast, sustainable, and cost-effective method on a broader range of nanomaterials. This study describes the laser-induced production of reduced graphene oxide with carbon nanotube (rGO/CNT) composites and their application as flexible electrodes. Conductive carbonized films were imprinted on a flexible substrate by CO2 laser (10.6 μm). The composites formation is supported by a detailed microstructural and chemical analysis, which confirms the structural integration of rGO with CNTs. Electrodes containing CNTs exhibit 7.5-fold increase in conductivity compared to only rGO electrodes. Importantly, when the electrodes are bent, the conductivity retention of the composite is significantly superior compared to the only rGO electrodes. Upon bending, the change in conductivity is lowered from 0.62 to 0.19. Furthermore, when used as electrodes in flexible supercapacitor devices, the composites with CNTs show 98.45 % retention in specific capacitance while maintaining structural integrity. In contrast, rGO electrodes without CNT addition deform upon bending and retain only 63.88 % of the relaxed specific capacitance.