Table 3: Metallic bipolar plates—base metals, coatings, fabrication techniques, and chemical and physical properties.

Base metalCoating materialDeposition methodTest environmentCorrosion current density (×10−6 A  cm−2)ICR (mΩ cm2)Sample size
𝑙 × 𝑤 × 𝑡 (mm)
PurgeReference

310 SSTiN-SBREPD0.05 M S O 4 2 + 2 ppm Fat 80°CSBR TiN 50 nm: 15.8 SBR TiN 1 μm: 31.7 no TiN: 40
(all at 180 N cm−2)
20 mm2 × 2 mm thick for polarization tests
80 mm2 × 6 mm thick for bipolar plate
Ar or Air[48]

304 SSCarbon with Nickle LayerCVD0.5 M H2SO4at 40°C[61]

316L SS
304 SS
Nicrofer 3127
Nicrofer 6020
Nicrofer 5923
CrN (deposited only on SS plates)PVD0.001 M H2SO4 0.00015 M HCl
15 ppm HF at 25–70°C
304 SS: 3.26
304 SS/CrN: 0.24
316L SS: 1.92
316 SS/CrN: 0.79
N3127: 3.14
N6020: 4.97
N5923: 1.95
(All for cathode at 0.7 V versus NHE)
Graphite:
 XM9612: 3.5
 BMA5: 14.5
Ni-based alloys:
 N3127: 3.8
 N5923: 3.9
 N 6020: 7.0
 304 SS: 95
 304 SS/CrN: 19
 316L SS: 90
 316L SS/CrN: 12
 (all at 220 N cm−2)
16 cm2H2 (an)
Air (cat)
[69]

316L SSCrN Physical vapour deposition (PVD)0.05 M H2SO4 + 2 ppm F at 70°C0.5 (an)
1.3 (cat)
30 at 150 N cm−210 × 10 × 6H2 (an)
Air (cat)
[84]

Austenite 304 SSNbN and NbN/NbCrNICP-sputtering0.5 M H2SO4 + 2 ppm HF at 70°CNbN: 8.26 × 10−3 NbN/NbCrN: 9.87 × 10−335 at 1.5 Mpa22 mm diameter
× 6 mm thick
[100]

304 SSCr3Ni2/Cr2N/CrNMagnetron sputtering0.5 M H2SO4+ 2 ppm HF
at room temp.
0.1 (cat)17 at 150 N cm−225 × 25 × 2[101]

316L SSCr/CrN/CrPulsed bias arc ion plating (PBAIP)0.5 M H2SO4 + 2 ppm Fat 70°C0.56–1.0035 at 150 N cm−2100 mm2 0.1 mm thick (plating)
15 mm2
0.1 mm thick (corrosion)
H2 (an)
Air (cat)
[102]

AISI 316LCrN,
Cr2N
Inductively coupled plasma (ICP) (530–650 K)0.1 N H2SO4 + 2 ppm HF
at 80°C
<4.3 (cat)
at 0.6 V, 590 K
80 (untreated)
40 (530 K)
13 (590 K)
11 (650 K)
all at 150 N cm−2
40 × 50 × 0.2[85]

316L SSCrNICP0.1 N H2SO4 + 2 ppm HF
at 80°C
0.157 at 0.6 V (−100 V)
0.166 at 0.6 V (−200 V)
0.944 at 0.6 V (−300 V)
(4.76 for bare 316L SS)
(25.5 for Cr-plated 316L SS)
82.2 at 150 N cm−2 79.3 (−100 V)
34.0 (−200V)
5.6 (−300 V)
0.2 mm thicknessH2 (an)
Air (cat)
[86]

316L SS(Ti, Cr) N 𝑥 ICP-ARMS0.5 M H2SO4 + 2 ppm HF
at 80°C
0.50 (cat)
0.05 (an)
(all at 0.6 V)
4.5 at 150 N cm−2H2 (an)
Air (cat)
[103]

Aluminum alloy Magnal-45 (Al-5082)CrN (3–5 μm thick)PVD0.5 M H2SO4 + 2 ppm HF
at 70°C
57.42 at 5 μm (an)
79.12 at 5 μm (cat)
8.0 at 3 μm
8.5 at 4 μm
6.0 at 5 μm
all at 135 N cm−2
1 cm2[104]

316L SSCr0.43N0.57
Cr0.49N0.51 (1),
Cr0.49N0.51 → Cr0.43N0.57 (2),
Cr0.43N0.57 (3)
PBAIP0.5 M H2SO4 + 5 ppm Fat 25 or 70°C(1): 10
(2): 1.0
(3): 31.6
316L SS: 100
(1) 14.1–19.6
(2) 7.9–11.2
(3) 6.9–10.0
(all at 0.8–1.2 MPa)
15 mm2 × 6 mm thick[107]

316L SSCrPack cementation in argon gas at 1100°C for 2.5–10 h0.5 M H2SO4at 80°Cbare 316L SS: 95
316L SS/Cr(2.5 h): 75
316L SS/Cr (10 h): 90
316L SS/Cr (5 h): 95
20 × 20 × 3 H2 (an)
Air (cat)
[83]

316L SSNi-CrIon implantation0.5 M H2SO4 + 2 ppm HF
at 80°C
0.07 (cat)
(2.5–3.0 for bare 316L SS)
22.1 at 210 N cm−2 50.0 at 150 N cm−2
(255.4 at 210 N cm−2
380 at 150 N cm−2
for bare 316L SS)
15 mm2 × 5 mm thickH2 (an) Air (cat)[108]

316L SS C r 𝑥 C 𝑦 PBAIP0.5 M H2SO4 + 5 ppm Fat 25°C and 70°C0.091 (25°C)
0.23 (70°C, air)
3.0 (70°C, H2)
2.8 (Cr0.23C0.77)
at 150 N cm−2
15 mm2 × 0.1 mm thickH2 (an)
Air (cat)
[109]

316L SSCrNPBAIP0.5MH2SO4 + 5 ppm Fat 25°C0.59 (16.0 for bare 316L SS)5.8 at 1.2 MPa15 mm2 × 0.1mm thick[87]

316 L SS Powder Mix I
(50 wt% Cr, 43 wt% Al2O3, 7 wt% NH4C)
Powder Mix II (25 wt% CR, 72 wt% Al2O3, 3 wt% NH4C)
CVD1.0 M H2SO4 at 80°C17 at 150 N cm−2 (sample I)
35.3 at 150 N cm−2
(bare 316L SS)
233.5 at 150 N cm−2
(sample II)
20 × 20 × 1 H2 (an)
Air (cat)
[110]

316L SSAg Ion implantation0.5 M H2SO4 + 2 ppm HF
at 80°C
2.0 (cat)>400 (untreated)
>100 (Ag)
all at 150 N cm−2
15 × 15 × 5[91]

316L SS NiIon implantation0.5 M H2SO4+ 2 ppm HF
at 80°C
bare 316L SS: 312.8
Ni coated: 36
(1 × 1017 ions cm−2)
Ni coated: 30.0
(5 × 1017 ions cm−2)
15 × 15 × 6
1.0 cm2 (for corrosion tests)
H2 (an)
Air (cat)
[114]

316 L SS ZirconiaSol-gel dip coating followed by calcination at 800°C for 1 hour1.0 M H2SO4at 80°C0.800 (56.68 for bare 316L SS)275 at 150 N cm−2 (104 at 150 N cm−2 for bare 316L SS)16 mm diameter × 2 mm thickH2 (an)
Air (cat)
[96]

316L SSAg-PTFE compositeElectrodeposition0.5 M H2SO4+ 5 ppm Fat 70°CAnode:
10−5.01 (PTFE-Ag)
10−6.3 (pure Ag)
2.88–3.94
(PTFE-Ag)
3.24–4.54
(pure Ag)
(all at 0.8–1.2 MPa)
100 mm2 × 0.1 mm thickH2 (an)
Air (cat)
[95]

316L SSC
C-Cr
C-Cr-N
PBAIP0.5 M H2SO4 + 5 ppm F at 25°C and 70°C0.1 (C-Cr)
10 (bare 316L SS)
C-Cr: 8.72
C-Cr-N: 555
Pure C: 2160
all at 1.5 MPa
100 × 100 × 0.1 H2 (an)
Air (cat)
[121]

316L SSAmorphous carbon (A-C)Closed field unbalanced magnetron sputter ion
deposition (CFUMSID)
0.5 M H2SO4 + 2 ppm HF at 80°C0.06
bare 316L SS:
43.1 (an), 21.0 (cat)
A-C: 8.3–5.2
Graphite: 10.4–5.4
bare 316L SS: 477-255.4
all at 120–210 N cm−2
15 mm2 × 5 mm thickH2 (an)
Air (cat)
[140]

316L SSLow-temperature plasma nitridation0.05 M H2SO4 + 2 ppm F at 70°C65 at 4 h (cat)
35 at 4 h (an)
1.0 cm2 × 6 mm thickH2 (an)
Air (cat)
[141]

304 SSA-C CFUMSIDSingle Cell and Short Stack (100 W) Cell Temp: 60°C Reactants: 80°C
H2 (30% RH)
O2 (30% RH)
5.4 at 1.5 MPa
(93.3 at 1.5 MPa
bare 304 SS)
100 × 100 × 0.1 None[142]

430 SSNiobiumRoll bonding0.001 M H2SO4 0.00015 M HCl
15 ppm HF at 25–70°C
69 (cat)
at 0.84 V versus
NHE
0.17 (an)
at 0.14 V versus NHE
430 SS/Niobium: 15
430 SS/CrN: 19
all at 220 N cm−2
H2 (an)
Air (cat)
[92]

310 SSTiN-SBRElectrophoretic deposition (EPD)0.05 M  S O 4 2 + 2 ppm F at 80°C<16Bare 310L SS: 100
TiN coated: 80
(all at 150 N cm−2)
20 × 20 × 2
for polarization
80 × 80 × 6
for corrosion test
Ar or Air[143]

SS 349
SS 2205
AISI 444
AISI 446
Fluorine-doped SnO2 (SnO2:F)Preetching with CBrF3 followed by Low-pressure chemical vapour deposition (LPCVD)1.0 M H2SO4 + 2ppm F at 70°CBare AISI 444: 90
coated AISI 444: 85
USDOT: 1.0 (an) bare AISI 444: 20 coated AISI
444: 46 (cat) all at 0.6 V
All >50 mΩ cm225.4 × 12.5H2(an)
Air (cat)
[144]