A study of the corrosive behavior of STS304 and STS 430, depending on surface pre-treatment conditions, in PEMFC while in operation

Abstract

In most cases, graphite is using as a construction material for bipolar plates in PEM fuel cells. Graphite has a stabilized chemical reaction and excellent electrical conductivity. However, it also has weaknesses in that it is costly and prone to gas leaks because of its structural properties. Graphite has a porous structure, so graphite plates are thick for preventing these gas leaks. Even though, gas retention is still an issue, and bipolar plate thickness may conversely need to be increased further. Finally, graphite is difficult and expensive to manufacture via machining because of how brittle it is. Metal is a very attractive material for the industrial fields. Some engineers expect to overcome the weaknesses of graphite as a construction material for bipolar plates through the implementation of metallic substitutes. Metal is inexpensive and easy to manufacture while boasting a high-density structure and good electrical conductivity. However, metal has one weakness: its tendency toward corrosion. This study focused on commercial stainless steel’s corrosion behavior in a standard PEMFC operating environment during a 100-hour time frame. We investigated for changes in the microstructure using OM, SEM, and XRD, for corrosion properties using ICP, and for electrical properties using Potentiodynamic polarization.