A spiral shaped regenerative microfluidic fuel cell with Ni‐C based porous electrodes

Abstract

Microchannel geometry, electrode surface area, and better fuel utilization are important aspects of the performance of a microfluidic fuel cell (MFC). In this communication, a membraneless spiral-shaped MFC fabricated with Ni as anode and C as a cathode supported over a porous filter paper substrate is presented. Vanadium oxychloride and dilute sulfuric acid solutions are used as fuel and electrolyte, respectively, in this fuel cell system. The device generates a maximum open-circuit voltage of ~1.2 V, while the maximum energy density and current density generated from the fuel cell are ~10 mW cm−2 and ~51 mA cm−2, respectively. The cumulative energy density generated from the device after five cycles are measured as ~200 mW after regeneration of the fuel by applying external voltage. The spiral design of the fuel cell enables improved fuel utilization, rapid diffusive transport of ions, and in-situ regeneration of the fuel. The present self-standing spiral-shaped MFC will eliminate the challenges associated with two inlet membrane-less fuel cells and has the potential to scale up for commercial application in portable energy generation.