Polyacrylonitrile Infused in a Modified Honeycomb Aluminum Alloy Bipolar Plate and Its Acid Corrosion Resistance

Abstract

Bipolar plates, accounting for a large proportion of proton exchange membrane fuel cells (PEMFCs), are highly susceptible to corrosion by H + , SO 4 2– , and so on because of the strong acid-rich and oxygen/hydrogen-rich environments. In this work, the corrosion resistance of aluminum alloy bipolar plates modified in the cathodic environment of PEMFCs has been investigated. A honeycomb structure is constructed by anodizing on an aluminum alloy (AA5052) bipolar plate, and a polyacrylonitrile (PAN) film is prepared by infusing PAN solution on the surface. From scanning electron microscopy and atomic force microscopy, we observe that the porous structure of the aluminum alloy surface is more advantageous for enhancing the mechanical engagement between PAN and the aluminum alloy. Therefore, the PAN film is dense and smooth. Electrochemical tests confirm that the PAN film greatly improves the corrosion resistance of the aluminum alloy bipolar plate under the cathodic environment of the PEMFC. When graphene oxide (GO) is added, the charge-transfer resistance ( R ct ) is not only improved but also the stability under oxygen-rich acidic conditions is prolonged.

Corrosion and Materials Degradation in Electrochemical Energy Storage and Conversion Devices

“…GO was beneficial in enhancing the coating stability in the acidic pH. After 5400 s of potentiostatic test at 0.6 V ( vs SCE) in an oxygen‐enriched acidic solution, the current density of the coated sample was maintained at 7.67×10 −7 A cm −2 [89] …”

“…After 5400 s of potentiostatic test at 0.6 V (vs SCE) in an oxygen-enriched acidic solution, the current density of the coated sample was maintained at 7.67 × 10 À 7 A cm À 2 . [89] As discussed in this section, novel alloy [83] or coating [84] fabrication approaches could yield better results. The selection of multilayer coating strategies needs precise optimization to keep the ICR values within the allowed DOE limit.…”

Research progress in surface modification of metal bipolar plates for proton exchange membrane fuel cells

“…Figure 8 Schematic diagram of preparation of graphene films on aluminum plates [33] (color online). [43] (网络版彩图)…”

Improving the Anti-Corrosion and Anti-Wear Performance of Anodic Coating on the Surface of AA 5052 via Hydro-Thermal Treatment

“…Using an anodizing method [5][6][7], a uniform alumina oxide can be prepared on the surface of the aluminium alloy. However, the coating is porous, its corrosion resistance is poor, and can only protect the substrate in the short-term [8][9][10]. To improve the anti-corrosion of the coating, usually, the through pore needs to be sealed.…”