Urea-based Fuel Cells on Paper with Micro-Watt Power Generationto Drive Low Power Circuits

Abstract

Abstract This work demonstrates the application of a urea-powered paper-based fuel cell (PFC) with Hydrogen Peroxide (H2O2) as the oxidant to drive a flexible electronic circuit (ring oscillator (RO)), for the first time. Herein, the electrochemical performance of membraneless PFCs is studied by employing different non-precious electrodes, such as, Nickel-mesh, Toray carbon paper(CP) and Nickel Cobalt nanoparticles supported on reduced Graphene Oxide loaded on the CP (NiCo@rGo@CP). A single-PFC with Ni-Co@rGo@CP as electrodes delivers a peak power density (Pmax) of 55 µW cm− 2, maximum current density (Jmax) of 371 µA cm− 2 and an open-circuit voltage (OCV) of 0.7 V at 3 M urea. A membrane-based PFC assembled onto an anion exchange membrane with Ni-Co@rGo@CP electrodes, delivers a Pmax of approx 70 µW cm− 2, Jmax of ≈ 500 µA cm− 2 and an OCV of 0.7 V at 3 M urea. Subsequently, a stack of two membrane-based PFCs delivers an OCV of ≈ 1.4 V for 400 seconds. Finally, this stack is employed as a power source to drive a RO. The measured frequency and peak-to-peak voltage are 37.52 kHz and 1.04 V, respectively. This demonstration opens a window to implement self-contained flexible electronic system using PFC as power source with minimal e-waste.