Selection of Graphite Pencil Grades for the Design of Suitable Electrodes for Stacking Multiple Single‐Inlet Paper‐Pencil Fuel Cells

Abstract

Abstract We present a single‐inlet paper‐pencil based microfluidic fuel cell which works on the capillary driven fluid flow of a mixture of fuel (formic acid) and electrolyte (dilute sulfuric acid) solutions as a single entity. Different types of pencils are used to prepare the graphite electrodes to observe their effect on the fuel cell performance. The graphite electrodes are porous and act as a gas diffusion electrode which breaths in oxygen directly from the quiescent air and out CO 2 from the cell. The paper fuel cell also fabricated in different dimensions and connected as cell‐stacks to enhance its performance. The paper‐pencil device generates maximum open circuit potential of ∼2.5 V in series combination and maximum current density of ∼ 82 mA cm −2 and power density of ∼ 100 mW cm −2 in parallel combination. Later, rGO−Cu/CuO nanocomposite embedded electrodes are used to observe their effect on the device performance.