Proton Exchange Membrane Fuel Cell Environment Research Articles

Temperature-relevant degradation in amorphous carbon coated SS316L bipolar plates for PEMFC

The corrosion of metallic Bipolar Plates (BPs) has become a key bottleneck in the practical application of proton exchange membrane fuel cells (PEMFCs). Environmental factors inside the PEMFCs significantly accelerate the degradation of electrical conductivity and durability of metallic BPs. In this work, we investigated the corrosion behavior and conductive properties of amorphous carbon coating (a-C) coated SS316L in a simulated PEMFC environment at various operating temperatures. The results showed that the corrosion current density (Icorr) of a-C varied in a range of 2.3–8.7 nA/cm2 when subjected to a temperature range of 40–80 °C. Additionally, the interfacial contact resistance increased from 4.36 to 9.56 mΩ/cm2 with a rise in temperature. The reasons could be ascribed to two aspects. First, the a-C maintained the good chemical stability of sp2/sp3 bonds regardless of temperature changes, favoring remarkable anti-corrosion and good conductivity. Second, the higher temperatures intensified the penetration of corrosive species, accelerating the dissolution process of a-C coated SS316L and leading to substantial corrosion failure.

Improved corrosion resistance and interfacial conductivity of a-C/(Ti:C)/Ti nano-thin film for 316L stainless steel bipolar plates

To enhance corrosion resistance and electrical conductivity of metallic bipolar plates for proton exchange membrane fuel cells (PEMFCs), the film containing amorphous carbon (a-C) outer layer, titanium carbon compound (Ti:C) transition layer and titanium (Ti) seed layer has been deposited on the surface of 316L stainless steel (316L SS) by multi-arc ion plating method. Dense and uniform a-C/(Ti:C)/Ti nano-thin film is relatively hydrophobic and approximately 300 nm thick, presenting a clear multilayer structure. The interfacial contact resistance of 316L SS is effectively reduced from 124.97 mΩ·cm2 to 3.97 mΩ·cm2 at 1.4 MPa after modification. Electrochemical corrosion tests are investigated in the simulated cathodic PEMFCs environment (0.5 M H2SO4 and 2 ppm HF at 70 ℃ bubbled with air). Potentiodynamic polarization results reveal that the corrosion potential of a-C/(Ti:C)/Ti film modified sample is 0.23 V (vs. Ag/AgCl) and the corrosion current density is only 0.14 μA·cm−2. The durability of the a-C/(Ti:C)/Ti film was assessed by conducting potentiostatic polarization tests at various applied potentials. After 4 h potential of 0.6 V and 0.8 V (vs. Ag/AgCl) holding tests, the current densities of the modified 316L SS have stabilized at 0.076 μA·cm−2 and 0.098 μA·cm−2, respectively.

Characterization of the performance of Ti doped α-C/α-C multilayer coating on SS316L as bipolar plates for PEMFC

In order to improve the corrosion resistance and conductivity of 316L stainless steel (SS316L) in the PEMFC (proton exchange membrane fuel cells) environment, DC-balanced magnetron sputtering was used to deposit Ti doped α-C/α-C multilayer coating on SS316L. The influence of coating structure on its micromorphology and phase composition is characterized, and the coating corrosion and conductivity were further explored. Notably, the investigation reveals that multi-layer structure can inhibit the growth of columnar crystal structure and refine the coating surface, which gradually decreased the coating porosity of from 4.54 % (1 layer) to 0.21 % (4 layers), and the passivation current density decreases to 0.22 μA/cm2 at 0.6 V, remarkably better than the targets. In addition, the introduction of Ti-doped α-C layer further promoted the sp2 hybridization of the coating, its interfacial contact resistance (ICR) value gradually decreased from 5.28 mΩ·cm2 (1 layer) to 2.28 mΩ·cm2 (4 layers) under 1.4 MPa. Therefore, the multilayer composite structure coating significantly enhances the conductivity and corrosion resistance of the SS316L bipolar plate, are more practically applied for commercialization of PEMFC technology.

Effect of aging temperature on corrosion resistance of 316L stainless steel in simulated proton exchange membrane fuel cell cathode environment

The effects of aging temperature on the corrosion behavior of 316 L stainless steel in a simulated cathodic environment of a proton exchange membrane fuel cell (PEMFC) were investigated by potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), double-loop electrochemical potential response (DL-EPR). The results show that the corrosion resistance of 316 L is significantly degraded after aging at 750–900 °C for 1 h in the simulated cathodic environment of PEMFC. A strong sensitivity to intergranular corrosion takes place after aging at 850 °C, and chromium rich M23C6 carbides precipitate on grain boundaries. The precipitation of M23C6 leads to discontinuity of the passivation film near the grain boundaries, resulting in Cr-depleted zones at the grain boundaries, increasing intergranular corrosion, and decreasing corrosion resistance. When the aging temperature exceeds 950 °C, grain boundary precipitation of M23C6 does not occur and the corrosion resistance is improved. At an aging temperature of 1050 °C, a dense Cr2O3 film is formed on the surface of the alloy during the polarization test, giving it the best corrosion resistance in the simulated cathodic environment of PEMFC.

Screening of sealing materials for PEM fuel cell applications based on weight factor method

AbstractThe inexpensive, endurable sealing members are among the key components determining the performance and durability of proton exchange membrane fuel cells (PEMFCs). However, there is a lack of effective in situ measurement to monitor the sealing performance change in the fuel cell operation environment. Therefore, the durability of a sealing material should be assessed previously to its application. The present work investigates four types of commercially available sealing silicone rubbers, and five groups of aging tests are carried out to compare their properties and durability in a simulated PEMFC environment, including compression set, stress relaxation, compression stress–strain, solution soaking, and low‐temperature characterization. Furthermore, to comprehensively evaluate the performance of these four types of silicone rubbers and screen out the most suitable one, a comprehensive evaluation table of sealing materials selection based on weight factor was established through an expert survey method, by which the experimental results of all the silicone rubbers can be weighted and scored. This method can be widely used in the fuel cell industry.

Effects of Nitrogen Flow Rate on the Performances of Cathodic Arc Deposited TiN Films on 316L Stainless Steels as Bipolar Plates for the Proton‐Exchange Membrane Fuel Cell

The corrosion resistance, interfacial contact resistance (ICR), and hydrophobicity of cathodic arc deposited TiN films on 316L stainless steels at different nitrogen flow rates as bipolar plates (BPs) for the proton‐exchange membrane fuel cell (PEMFC) are investigated. It is shown in the results that the TiN‐coated 316L stainless steel prepared at a moderate nitrogen flow rate (250 sccm) exhibits a low stable corrosion current density of 6.5 × 10−8 A cm−2 in the simulated corrosive cathode environment of PEMFC, and a low ICR of 8.94 mΩ cm−2 at a pressure of 1.38 MPa after corrosion, meanwhile presents a good hydrophobicity before and after corrosion. These results are discussed by considering the probable effects of the nitrogen flow rate on the substrate/coating system based on the microstructural characterization of the substrate/coating interface and the coating, which shows that the interdiffusion will be started in the deposition process and a moderate nitrogen flow rate during the coating process will promote to the broadening of interface region and lead to the formation of a robust and high‐quality coating with fewer defects that can effectively improve the performances of the 316L stainless steel substrate as the BP for PEMFC.

Corrosion Behavior of Coated Low Carbon Steel in a Simulated PEMFC Environment.

Here, potential metallic bipolar plate (BP) materials were manufactured by laser coating NiCr-based alloys with different Ti additions on low carbon steel substrates. The titanium content within the coating varied between 1.5 and 12.5 wt%. Our present study focussed on electrochemically testing the laser cladded samples in a milder solution. The electrolyte used for all of the electrochemical tests consisted of a 0.1 M Na2SO4 solution (acidulated with H2SO4 at pH = 5) with the addition of 0.1 ppm F-. The corrosion resistance properties of the laser-cladded samples was evaluated using an electrochemical protocol, which consisted of the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) measurements, and potentiodynamic polarization, followed by potentiostatic polarization under simulated proton exchange membrane fuel cell (PEMFC) anodic and cathodic environments for 6 h each. After the samples were subjected to potentiostatic polarization, the EIS measurements and potentiodynamic polarization were repeated. The microstructure and chemical composition of the laser cladded samples were investigated by scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX) analysis.

Superior conductive polypyrrole anti‐corrosion coating doped with titanium nitride for 304 stainless steel bipolar plates

AbstractThe conductivity and corrosion performance of metallic bipolar plates were crucial to the development of the proton exchange membrane fuel cell (PEMFC). In this study, polypyrrole (PPy) coatings doped with titanium nitride nanoparticles (TiN NPs) were deposited on 304 stainless steel (304SS) by constant potential polymerization. To improve dispersion and form a negative charge surface, TiN NPs were modified by anionic surfactants such as sodium dodecyl diphenyl ether disulfate (MADS). Through comparing potentiodynamic curves of the composite coatings in the simulated cathodic environment of PEMFC, the PPy‐0.1 TiN (0.1 g/L) coating presented a more positive corrosion potential (Ecorr = 293 mVAg/AgCl) and a lower corrosion current (Icorr = 0.841 μA cm−2). Furthermore, PPy‐0.1 TiN exhibited more stable corrosion resistance during long‐term immersion. Interfacial contact resistance (ICR) testing demonstrated that the addition of TiN NPs improved conductivity compared to a PPy coating. The results indicated that the PPy‐TiN‐coated 304SS could be used as a kind of promising bipolar plate material.

Temperature Effect on Corrosion Rate of Metal AA 5052 Using D-Galactose Inhibitors In Sulfuric Acid Media With Electrochemical Method

Aluminum Alloy 5052 (AA 5052) is a metal that can be used as a biopolar plate in proton exchange membrane fuel cell (PEMFC), because it has the advantages of being resistant to corrosion, high conductivity, easy shape and light weight. PEMFC produces electrical energy and the rest of the process in the form of hot water and steam. In a bipolar plate PEMFC environment corrosion can easily occur due to an acidic environment and high operating temperature around 40°C-80°C. For this reason, a treatment is needed to strengthen the corrosion-resistant properties of AA 5052. The coating of the material can be done using the technique of electrophoretic deposition (EPD) using green inhibitor to reduce the corrosion rate. The electrochemical method was carried out to see how much influence temperature had on the corrosion rate of AA 5052. In this study, d-galactose green inhibitor with a concentration of 0.5 g, EPD time of 20 minutes was used, in a PEMFC environmental simulation in 0.5 M H2SO4 sulfuric acid medium, with test temperatures of 25°C (room temperature), 40°C, 60°C, and 80°C. From the results of the analysis using the electrochemical method, there was an effect of temperature on the corrosion rate of AA 5052 without an inhibitor layer of 0.3610 mmpy at room temperature and increased at 80°C 3.9527 mmpy. While AA 5052 which was coated with a d-galactose inhibitor, had a corrosion rate of 0.1678 mmpy at room temperature and continued to increase at a temperature of 80°C 3.7745 mmpy. Inhibitor efficiency was 53.51% at room temperature and decreased with increasing temperature to 4.5% at 80°C.

TiCr transition layer promoting the growth of high-stability TiCrN coating for titanium bipolar plate

High chemical stability under the harsh acidic working condition of proton exchange membrane fuel cell (PEMFC) is of great importance for bipolar plates. In present study, a series of TiCr alloys from amorphous to nanocrystalline state are designed as transition layers to promote the growth of smooth and dense TiCrN surface layer as coating material for Ti bipolar plate. Under the accelerated corrosion environment of PEMFC (0.5 M H2SO4 + 2 ppm HF, 80 °C with air, 0.2 V vs. Hg/Hg2SO4), the double-layer TiCr/TiCrN coating exhibits excellent long-term stability. A low current density of 0.25 μA/cm2 and a small interfacial contact resistance (ICR) of 6.5 mΩ cm2 are observed after 100 h corrosion test for the double-layer TiCr/TiCrN, which are much lower than the values of 1.35 μA/cm2 and 13.5 mΩ cm2 for single-layer TiCrN after 70 h corrosion test. These results indicate the high potential of double-layer TiCr/TiCrN as the coating material for Ti bipolar plate.

Development of Corrosion Resistant and Electrically Conductive Coatings on Metallic Bipolar Plates for Applications in PEMFC

Proton exchange membrane fuel cell (PEMFC) is considered as one of the most promising alternative energy devices due to its high efficiency, low pollutants emission and possible application in automobiles. However, the application of PEMFC is still hindered by the high cost of some of its components such as bipolar plates (BPP) which are a key component in PEMFC to facilitate electron transfer, gas flow, heat and water removal. To reduce the cost, increase conductivity and durability, metallic bipolar plates, typically made of stainless steel, are normally used but they could suffer from severe corrosion in the acidic environment of PEMFC; the formation of corrosion products on the metal surface could reduce the through-plane electrical conductivity and increase the interfacial contact resistance (ICR) between the bipolar plates and gas diffusion layer, eventually causing high power loss in the fuel cell stack. Therefore, developing corrosion resistant and electrically conductive bipolar plates is of vital importance for the practical applications of PEMFC.Transition nitride coated stainless steel, such as titanium nitride (TiN) coated 316L SS, is considered as a possible solution to improve the performance metallic bipolar plates. In this work, TiN coated 316L SSs with heat treatment at different temperatures were prepared. The corrosion behaviours of the prepared samples were investigated in the simulated working environments of fuel cell. The heat treated samples exhibit the improved corrosion resistance compared with the pristine TiN coated samples and with an increase of the heat treatment temperature, the corrosion resistance tends to increase due to the formation of oxide and oxynitride on the sample surface. The ICR test results indicate that high temperature (450 ℃) heat treatment has detrimental effect on the electrical conductivity of samples due to the formation of a thick oxide dominated layer, while the samples heat treated at 300 ℃ only form the graded layers with suitable oxide amount which endows the coated specimens with a very low ICR value both before and after the corrosion tests.Moreover, TiN coatings with different amounts of Ta addition were also prepared. After the corrosion tests in the H2SO4 solution with pH=3 at 70 ℃, the results reveal that Ti150Ta30N samples exhibit the highest corrosion resistance compared with the pristine TiN coated samples and the samples with different amount of Ta addition. The steady state current density of Ti150Ta30N samples after long term potentiostatic polarization at 0.6 V (vs Ag/AgCl) is 0.02 μA/cm2 which is much lower than that of TiN coated samples. The Ti150Ta30N samples also presents a good electrical conductivity with low ICR values before and after the corrosion tests. These studies suggest that a suitable amount of oxygen or Ta incorporation into TiN is a feasible strategy to improve the corrosion resistance while maintaining considerable electrical conductivity of TiN samples.

Characterization and properties of NbN–Nb bilayer formed on titanium for bipolar plates

In this study, the NbN/Nb bilayer structure was prepared by duplex-treatment (plasma surface alloying + nitriding) on titanium used as bipolar plates for proton exchange membrane fuel cells (PEMFCs). Niobium coating was deposited on titanium by means of double glow plasma surface alloying technique. Then, a thin NbN layer was created by plasma nitriding. The corrosion resistance and electrical conductivity of samples were measured in simulated PEMFCs environments. The result shows that at an applied potential of 0.6 V the corrosion current density of duplex-treated sample is two orders lower than that of untreated titanium. After corrosion testing at 0.6 V for 4 h, the interfacial contact resistance is 5.1 mΩ cm2 compared with 29.7 mΩ cm2 for untreated titanium.

NbC/Nb Film-Modified Stainless Steel Bipolar Plate for Proton Exchange Membrane Fuel Cell

The NbC/Nb composite film on SS304 as the bipolar plate of proton exchange membrane fuel cell (PEMFC) was prepared by magnetron sputtering deposition. Scanning electron microscopy and x-ray diffraction were used to characterize the morphology and composition of the film. Electrochemical tests under simulated PEMFC operating conditions (pH 3 H2SO4, 0.1 ppm HF at 80°C) show that the NbC/Nb composite film can provide better corrosion resistance. Potentiodynamic polarization tests reveal that NbC/Nb/SS304 shows lower corrosion current density and more positive corrosion potential than Nb/SS304 and SS304 substrate in simulated PEMFC environments. Potentiostatic tests were also performed at the potentials of 0.84 VSHE for 24 h to simulate the cathodic PEMFC conditions. NbC/Nb/SS304 reaches the lowest polarization current density of 1.01 × 10−7 A/cm2, which is lower than Nb/SS304 (1.83 × 10−7 A/cm2) and SS304 (1.11 × 10−4 A/cm2, four orders of magnitude as low). Under the pressure of 140 N/cm2, the interfacial contact resistance value of NbC/Nb/SS is 8.76 mΩ·cm2, which is significantly lower than Nb/SS304 (14.0 mΩ·cm2) and SS304 substrate (224 mΩ·cm2). After 0.84 VSHE potentiostatic polarization for 24 h, NbC/Nb/SS304 increase by just 0.42 mΩ·cm2 (from 8.76 mΩ·cm2 to 9.18 mΩ·cm2). However, Nb/SS304 increase by 1.2 mΩ·cm2 (from 14.0 mΩ·cm2 to 15.2 mΩ·cm2) and SS304 increase by 64 mΩ·cm2 (from 224 mΩ·cm2 to 288 mΩ·cm2). Moreover, the hydrophobic angle of NbC/Nb/SS304 is 116.5°, compared to Nb/SS304 (108.8°) and SS304 substrate SS304 (67.5°), which is beneficial to the drainage of the PEMFC.

Doping and stress induced failure of Ti(Al/Pt)N films on Ti6Al4V plate in a simulated PEMFC environment

Ti(Al/Pt)N films prepared on Ti6Al4V (TC4) plates were soaked in a simulated proton exchange membrane fuel cell (PEMFC) anode environment for three weeks. The dense Ti(Al/Pt)N films exhibited various preferred orientations: TiN and TiAlN films with (111) and TiAl(Pt)N film with (200) orientations. The inner stresses of the Ti(Al/Pt)N films changed from −13 MPa for TiN, −115 MPa for TiAlN, and −66 MPa for TiAl(Pt)N. The corrosion current densities of TiN, TiAlN, and TiAl(Pt)N were of the order of 10−8, 10−7 and 10−6 A·cm−2, respectively. Their corresponding contact resistance values decreased sequentially from 29.85, 15.25 and 9.85 mΩ cm2. The appearance of second EIS impedance circles after soaking the films in the simulated PEMFC environment for 3 weeks was indicative of the corrosion failure of the Ti(Al/Pt)N films. The relatively high inner stress in the TiN film led to the formation of oxides and corrosion pits. Peeling of the TiAlN film off the TC4 occurred owing to the high inner stress. The micro-potential difference between the TiAlN columns and Pt particles that were distributed along the column boundary led to the formation of crack networks in the TiAl(Pt)N film. Al/Pt in TiN deteriorated the durability of the films, although it enhanced their conductivity.

Research on the performance of carbon film formed on thin stainless steel bipolar plates of PEMFC by laser irradiating

In order to improve the anti-corrosion performance of thin stainless steel bipolar plates of proton exchange membrane fuel cell (PEMFC), the carbon film (of about 0.82-[Formula: see text]m thickness) was fabricated on the thin stainless steel by laser direct writing technology irradiating the formed dense polydopamine (PDA) film. The results indicated that the PDA film has partially transformed into nanocrystalline graphite. Laser power and scanning speed had great effect on the anti-corrosion performance of the final obtained film in simulated PEMFC environment. When the laser power is 3.5 W and the scanning speed is 10 mm/s, the film obtained on the thin stainless steel has the best electrochemical performance in simulated PEMFC environment. Its corrosion current densities were [Formula: see text]A [Formula: see text] cm[Formula: see text]@ −0.1 V (versus SCE) and [Formula: see text]A [Formula: see text] cm [Formula: see text]@ 0.6 V (versus SCE) in simulated anode and cathode environments, respectively. Compared with the bare thin stainless steel, the corresponding corrosion current densities decreased by 45% and 62%. The results obtained in this text provide a novel strategy for modifyingPEMFC thin metal bipolar plates.

Nanocrystalline TaCN coated titanium bipolar plate dedicated to proton exchange membrane fuel cell

To promote the corrosion resistance and surface conductivity of metal bipolar plates (BP) in proton exchange membrane fuel cells (PEMFC), a TaCN nanoceramic coating with TaN and TaC dual phase structures was engineered onto a commercially pure titanium substrate employing the double cathode glow discharge plasma (DCGDP) technique. The as-prepared TaCN coating was well-adhered to the substrate with a thickness of ∼16.5 μm. The coating exhibited a microstructure comprising equiaxed grains with an average size of ∼10.3 nm. The electrochemical behavior of the TaCN coating was evaluated in a simulated PEMFC environment containing various HF concentrations. Open circuit potential (OCP), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), potentiostatic polarization, and Mott-Schottky tests showed that the addition of HF enhanced the corrosion rate of both the Ti substrate and the TaCN coating. Nevertheless, the TaCN coating exhibited improved corrosion potential, lower corrosion current density and larger resistance than that of Ti for all HF concentrations. The Hilbert-Huang and corrosion morphology analysis indicated that the TaCN coating maintained a passive state with increasing HF concentration. First-principle calculations investigated the adsorption capacity of the F− ions on the passive film on the TaCN coating. Furthermore, the TaCN coating possesses desirable interfacial contact resistance (ICR) (about 10 mΩ cm2 under a compressive force of 140 N cm−2) and outstanding hydrophobicity (92.9° ± 2°). Overall, the TaCN coating, which can deliver appreciable enhancement relative to the performance of titanium, represents an extremely competitive candidate as a protective coating for bipolar plates.

Titanium bipolar plates augmented by nanocrystalline TiZrHfMoW coatings for application in proton exchange membrane fuel cells

A TiZrHfMoW refractory high entropy alloy (RHEA) nanocrystalline coating was engineered onto a commercially pure Ti (CP-Ti) substrate to enhance its corrosion resistance for potential application as bipolar plates for use in proton exchange membrane fuel cells (PEMFCs). The as-prepared RHEA coating possesses a single-phase BCC structure with an average grain size of ∼12 nm. The electrochemical corrosion behavior of the RHEA coating in simulated PEMFC environment, with varying HF concentrations, was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), in conjunction with detection and analysis of electrochemical noise (EN). The potentiodynamic polarization and EIS measurements of the RHEA coating indicated that, at a given HF concentration, the RHEA coating exhibits a higher Ecorr, a lower icorr and a larger resistance value compared to uncoated CP-Ti. The analysis of the EN signals indicated that the RHEA coating has low correlation dimensions (below 1.4) and small instantaneous amplitudes in the Hilbert spectra, confirming that the RHEA coating was capable of maintaining a stable passive state, regardless of the HF concentrations. Furthermore, the electron work function of TiZrHfMoW RHEA was derived by first-principles calculations to unravel the physics origin of the corrosion resistance of the RHEA coating.

Investigation of anodized Ta/Ag coating on magnesium bipolar plate for lightweight proton exchange membrane fuel cells

High corrosion tendency is the bottleneck problem in the application of magnesium as lightweight bipolar plate for proton exchange membrane fuel cells (PEMFCs). This study proposes an innovative anodized Ta/Ag coating on Mg substrate, which is capable of significantly improving the anti-corrosion and electrical conduction abilities simultaneously. The corrosion behavior of the coating during immersion in the PEMFCs environment was investigated and compared with that in the working condition. In addition, the underlying mechanism of the corrosion behavior was discussed.

Data-driven coordinated control method for multiple systems in proton exchange membrane fuel cells using deep reinforcement learning

To improve the stability and operating efficiency of a proton exchange membrane fuel cell (PEMFC) system, a distributed deep reinforcement learning-based data-driven coordinated control method is proposed for realizing the coordinated control of a PEMFC gas supply system and heat management system. In addition, a siphonophora multiagent double-delay deep deterministic policy gradient (SMA-4DPG) algorithm is proposed for this method. The design of the algorithm is based on bionics in that it imitates the feeding and survival strategies of a siphonophora, a jellyfish creature with a hydra-like structure. The algorithm utilizes different exploration principles for exploring the PEMFC environment to improve the robustness of the coordination strategy in a manner similar to the siphonophora with its different prey-seeking organs. With this algorithm, the gas supply system and the heat management system are treated as two agents. Through centralized training, agents with different objectives and time scales can coordinate with each other and improve the stability of the PEMFC output voltage and stack temperature. The effectiveness of the proposed algorithm is demonstrated in a series of experiments in which its performance is compared with that of a conventional controller.

The Effects of Testing Conditions on Corrosion Behaviours of SS316L for Bipolar Plate of Proton Exchange Membrane Fuel Cell

Proton exchange membrane fuel cell (PEMFC) has been regarded as the most promising technology for solving problems, such as energy shortage, environmental pollution and global warming caused by fossil fuels due to its high efficiency, low operating temperatures, near zero emission and unlimited sources of hydrogen. However, large-scale commercial application of PEMFC is still hindered by high cost, limited performance and durability. As one of the key components, bipolar plate (BPP) has a great impact on performance, durability and cost of PEMFC. Stainless steel 316L (SS316L) has been considered to be one of the most appropriate candidates for automotive application because of its high thermal and electrical conductivity, superior mechanical properties, ease of manufacture and relatively low cost. However, release of metal ions and improvement of interfacial contact resistance (ICR) caused by corrosion of stainless steel BPP in PEMFC working environment still remains a big challenge. The corrosion of BPP may lead to deteriorate of performance and durability, or even the damage of PEMFC. Therefore, it is important to improve the performance, durability and lower the cost by seeking the appropriate base or coating materials for BPP. Because of the complexity of working conditions for BPP in a PEMFC, it is also critical to determine a reliable assessment method for evaluating corrosion resistance of materials for BPP. The typical working environment of PEMFC is normally considered to be weak acidic with pH in the range of 3 ~ 6 and contain different cations, such as F-1 and Cl-1 while the temperature is in the range of 60 ~ 80 ℃. However, most of the studies for measuring the corrosion resistance of BPP materials are conducted in a much harsher condition of 0.5 ~ 1 M H2SO4 (pH about 0.3 ~ 0) and 2 ppm HF with temperature in the range of 70 ~ 80 ℃. Although a few researches have been carried out to study individually the effects of pH or temperature on corrosion resistance of stainless steel for BPP, the combined effects of pH, temperature and bubbled gas on corrosion resistance of SS316L have not been investigated. In addition, the effects of high potential on corrosion behaviours of SS316L are neglected in former studies. In this work, the effects of temperature, pH, bubbled gas and potential on corrosion behaviours of SS316L are studied comprehensively. Moreover, SEM, EBSD and EDX are performed to reveal the mechanism of microstructure and chemical composition evolution of SS316L under different testing conditions mentioned above. The results reveal that temperature, pH and bubbled gas all have significant influences on corrosion potential (Ecorr.), corrosion current density (Icorr.) and passive current density (Ip) of SS316L. Besides, the influence of any one of the aforementioned factors on corrosion behaviour of SS316L is determined by the other two factors. Icorr. of SS316L in logarithm is generally proportional to pH at all temperatures in both argon or oxygen bubbled solutions. There are distinct passive regions for the Tafel curves of SS316L when potentiodynamic tests are performed in accelerated solutions with pH in the range of 0 ~ 1. On the contrary, pseudopassive behaviour would occur when SS316L are tested in the simulated conditions with pH in the range of 3 ~ 5. The results also indicate that severer corrosion would appear as higher potential is applied on SS316L. Pitting are shown to be the main corrosion for SS316L subjected to simulated solutions while the main corrosion mechanism is shifted to intergranular or uniform corrosion for SS316L under harsher testing conditions with pH in the range of 0 ~ 1. Figure 1