Laser induced graphene electrodes enhanced with carbon nanotubes for membraneless microfluidic fuel cell

Laser-induced graphene (LIG) is a recently explored three dimensional porous material with excellent properties offering flexibility in fabrication and acceptability for various applications. In the present work, a low-cost microfluidic fuel cell with LIG electrodes has been proposed. Herein, investigations on various parameters (fluid concentration, catalyst types, and flow rate) have been performed to optimize the performance of the fuel cell. The LIG electrodes of the microfluidic fuel cell have been fabricated using CO2 laser on the polyimide substrate, which are integrated into polydimethylsiloxane (PDMS) microchannel, developed by a conventional soft-lithography method. Here, LIG electrodes served as anode and cathode, while oxygen (atmospheric air) as an oxidant, formic acid and sulphuric acid have been used as fuel and electrolyte respectively for conducting ionic exchange under co-laminar flow. The LIG electrodes were further modified with various catalyst materials to enhance the performance of the fuel cell. The developed fuel cell with Ag nano ink as an optimized catalyst provided a maximum open circuit potential of 740 mV, peak current of 765.06 mu Acm(-2) and power density of 88.80 mu Wcm(-2) at a flow rate of 24 mlhr(-1).