Anode ink formulation for a fully printed flexible fuel cell stack

Abstract

Abstract In fuel cells the underlying reactions take place at the catalyst layers composed of materials favoring the desired electrochemical reactions. This paper introduces a formulation process for a catalyst inkjet ink used as an anode for a fully printed flexible fuel cell stack. The optimal ink formulation was 2.5 wt% of carbon–platinum–ruthenium mixture with 0.5% Nafion concentration in a diacetone alcohol solvent vehicle. The best jetting performance was achieved when 1 wt% binder was included in the ink formulation. Anodes with resistivity of approximately 0.1 Ω cm were inkjet printed, which is close to the commercial anode resistivity of 0.05 Ω cm. The anodes were used in fuel cell stacks that were prepared by utilizing only printing methods. The best five-cell-air-breathing stack showed an open circuit potential under H2/air conditions of 3.4 V. The peak power of this stack was 120 µW cm−2 at 1.75 V, with a resistance obtained from potentiostatic impedance analysis of 295 Ohm cm2. The printed electrodes showed a performance suitable for low-performance solutions, such as powering single-use sensors.