Chromium
(Cr) evaporation of ferritic stainless steel (FSS) interconnects
is considered to be the main reason for severe deterioration of solid
oxide fuel cells (SOFCs). To suppress the influence of Cr evaporation,
the development of a protective coating material on the FSS interconnects
has been proved to be an effective way. Herein, we prepare a Co-containing
protective coating via a facile pack cementation technique in different
atmospheres on an AISI 430 FSS interconnect. The obtained coating
is valid for enhancing the oxidation resistance and electrical performance
of the FSS interconnect. After the isothermal oxidation test, the
weight gain of the coated sample in Ar (0.415 mg/cm2) is
smaller than that of uncoated (1.613 mg/cm2) and coated
samples in air (0.498 mg/cm2). In addition, after the area
specific resistance (ASR) test, the coated sample (73.68 mΩ
cm2) in Ar has the lowest ASR compared with the uncoated
(236.88 mΩ cm2) and coated samples in air (96.32
mΩ cm2). These results indicate that the formation
of the CoFe2O4 spinel layer heightens oxidation
resistance and electrical properties through preventing the outward
diffusion of Cr3+ and inward diffusion of O2–. This work verifies that the Co-containing protective coating prepared
in Ar is a promising coating material for SOFC applications.
The electrical conductivity, corrosion resistance and hydrophobic property of bipolar plate are important factors to affect the overall performance of proton exchange membrane fuel cell (PEMFC). In order to improve the performance of bipolar plate, ZrC coating has been prepared on bare Ti plate by plasma surface modification technology. From the microscopic morphology characterization, it can be found that the surface of ZrC modified plate is smooth without obvious defect. The potentiodynamic polarization and potentiostatic polarization tests are measured in cathodic and anodic environment of PEMFC. The result shows that the corrosion current density of ZrC coated Ti plate decreases by 1-2 orders of magnitude compared with bare Ti plate. Moreover, the interfacial contact resistance (ICR) decreases from 110 mΩ cm 2 to 7.70 mΩ cm 2 under the compaction force of 140 N cm-2. In addition, the ICR of ZrC coated Ti plate slightly increases after potentiostatic polarization, indicating that a good electrical conductivity and durability is obtained by ZrC coated Ti plate. Furthermore, the ZrC coated Ti plate has a lower water contact angle (105°) than bare Ti plate (76°), indicating a better hydrophobic performance for water management.
The drawback of corrosion resistance and surface conductivity are two obvious defects to limit the large-scale application of 316L stainless steel (316L SS) as bipolar plate (BP) in proton exchange membrane fuel cell (PEMFC). A tantalum (Ta) modified coating was prepared by plasma surface modification technology on the surface of 316L SS bipolar plate to improve the functional performance. The electrochemical behavior of untreated 316L SS and Ta modified bipolar plate was investigated in simulated PEMFC operating environment. The results of potentiodynamic polarization, potentiostatic polarization and electrochemical impedance spectroscopy (EIS) reveal that the Ta coating considerably improves the corrosion resistance of 316L SS bipolar plate. The poten-tiodynamic polarization result shows that a more positive self-corrosion potential is obtained by Ta modified bipolar plate, and the corrosion current density is obviously reduced to 1.95 μA cm -2 and 0.14 μA cm -2 in simulated cathodic and anodic environment, respectively. The Ta modified bipolar plate exhibits a satisfactory interfacial contact resistance (ICR), and still remains lower ICR than bare substrate after potentiostatic polarization test for 4 h. In addition, the high water contact angle (94.5°) for Ta coated bipolar plate implies more superior hydrophobic performance, which is convenient for water management within the PEMFC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.