Investigation on the electro-osmotic drag coefficient of Nafion/SiO2 composite membranes with different SiO2 contents

Abstract

Electro-osmotic drag of the proton exchange membrane is significant in an operating proton exchange membrane fuel cell because it directly affects water management and fuel cell system. In this paper, a method using a hydrogen pump cell to measure the electro-osmotic drag (EOD) coefficient of Nafion212/SiO2 composite membranes with different SiO2 contents is described. It is found that the EOD coefficient of Nafion212/SiO2 composite membranes decreases with the increase of SiO2 content in the composite membranes and increases with the increase of cell temperature but remains essentially constant for various levels of applied currents. An empirical equation of the EOD coefficient of Nafion212/SiO2 composite membranes as a function of SiO2 content and temperature is proposed through numerical fitting while the temperature ranges from 323 to 363 K and SiO2 content in the composite membranes ranges from 0 to 19.8 %. These works will provide relative parameters for the numerical study on the proton exchange membrane fuel cell based on Nafion212/SiO2 composite membranes. • We measure EOD of Nafion212/SiO2 composite membranes by using the hydrogen pump cell method under a similar condition to operating proton exchange membrane fuel cell (PEMFC). • The EOD coefficient of Nafion212/SiO2 composite membranes decreases with the increase of SiO2 content within Nafion212/SiO2 composite membranes. • The EOD coefficient of Nafion212/SiO2 composite membranes increases with the increase of the cell temperature. • We obtain empirical equation of the EOD coefficient of Nafion212/SiO2 composite membranes as a function of SiO2 content and temperature through numerical fitting while the temperature ranges from 323 to 363 K and SiO2 content in the composite membranes ranges from 0 to 19.8 %.