Strategies for Reducing the Ohmic Resistance in a Proton Exchange Membrane Electrolysis Cell

Abstract

Ohmic polarization caused by the contact resistance between components and their own bulk resistance is the main polarization loss in proton exchange membrane electrolysis cells. To investigate this, we adopted an electrolysis cell with an active area of 25 cm2 and explored methods of reducing ohmic resistance. First, two kinds of polar plate were designed to investigate the contact area between transport layer and catalytic layer. The results showed that the polar plate with the higher ridge area made the transport layer and catalytic layer achieve good contact, resulting in an ohmic resistance decreases of 17.5 mΩ cm2 when the contact area increases from 16.85 to 21.6 cm2. Second, Pt coating was used to prevent oxidation of the titanium felt and improve electrolytic performance. Sputtering titanium felt exhibits the best performance with the electrolysis voltage of 1.814 V at 2 A cm−2. Finally, we studied different proton exchange membranes and analyzed the performance and hydrogen permeation rate with the self-made membrane electrode, finding that the electrolytic voltage of the Solvay E98–05 S reaches 1.733 V at 2 A cm−2 due to the minimum thickness and the highest conductivity, and the H2 permeation current density is only 2.184 mA cm−2.