A Simple and Accurate Method for High‐Temperature PEM Fuel Cell Characterisation

Abstract

A set of basic parameters for any polymer electrolyte membrane fuel cell (PEMFC) includes the Tafel slope b and the exchange current density j* of the cathode catalyst, the oxygen diffusion coefficient Db in the cathode gas‐diffusion layer and the cell resistivity Rcell. Based on the analytical model of a PEMFC [A. A. Kulikovsky, Electrochim. Acta (2004) 617], we propose a two‐step procedure allowing to evaluate these parameters for a high‐temperature PEMFC. The procedure requires two polarisation curves measured at different oxygen (air) stoichiometries. The method is validated using the experimental data obtained with the in‐house designed cell. High quality of fitting confirms validity and accuracy of this approach. The physical background of the method is discussed.

A Quasi 2D Model of a High Temperature Polymer Fuel Cell for the Interpretation of Impedance Spectra

“…The effective diffusion coefficient is corrected accounting for the porosity and the tortuosity of the GDL [4]. The resulting effective diffusion coefficient of oxygen is in the order of 0.03 cm 2 s -1 , similar to that reported in [25] where a value of 0.02 cm 2 s -1 is reported. The low value of the diffusion coefficient may be due to the presence of a microporous layer (MPL): a typical overall diffusion coefficient of GDL with MPL is in the range of 0.03 cm 2 s -1 [26].…”

“…Since EIS is a measurement of the slope of the losses, no effect is observed. [14]; 6 10 -2 [15] a σ (-) 2 2.6 10 -2 [35] a C (-) 0.85 0.8 [39]; 0.78 [25]; 0.89 [20]; 1 [42]; 0.73 [35]; 1 [14]; 0.8 [15] b (mV dec -1 ) 101 108 [39]; 111 [25]; 91 104 [21]; 97 [20]; 86 [42]; 118 [35]; 86 [14]; 108 [15] i* (A cm -3 ) 1.55 10 -2 1.3 10 -3 [14] i* (A cm -2 Pt ) 4.7 10 -9 a 1.8/24 10 -9 [21]; 1.4 10 -9 [20]; 29 10 -9 [35] i* δ CL (A cm -2 ) 4.7 10 -5 2.1/4.1 10 -5 [39]; 1.5 10 -5 [25]; 6.9 10 -6 [42]; 3.8 10 -5 [15] D O2 (cm 2 s -1 ) 10.8 10 -4 et À1 el (-) 1.2 10 -2 3.2 10 -2 [29]; 14 10 -2 [14] C DL (F cm -3 ) 9 140 [14] C DL (F cm -2 ) 2 7 10 -3 50 10 -3 [15] s 0 e 1:5 PA (S cm -1 ) 2.79 10 -2 13 10 -2 [20]; 0.16 10 -2 [14] a Exchange current density calculated with an active area of 145 cm 2 cm -2 measured by cyclic voltammetry and O 2 solubility in PBI + phosphoric acid from Ref. [21].…”

Polymer fuel cells based on polybenzimidazole/H3PO4

“…Impregnation with about 20 mg cm À2 of H 3 PO 4 was reported. 68 In our recent paper, 44 we demonstrated that better results can be obtained by impregnating the anode and the cathode with different amounts of H 3 PO 4 , namely 20 mg cm À2 and 8 mg cm À2 , respectively. However, scarce information may be found in the literature on this issue, and further systematic work is needed for MEA optimization.…”

“…The ink was spray-coated on the anode and cathode gas diffusion layers (GDL, Sigracet 10DC, SGL Group). Another recipe employing a different binder was proposed by Kulikovsky et al 68 In this case, gas diffusion electrodes (GDEs) with a platinum loading of 1.2 mg cm À2 were prepared by coating an ink containing 20 wt% Pt/C catalyst (HiSPEC 3.000, Johnson Matthey) and PTFE (Dyneon) onto a woven gas diffusion layer (GDL, HT 1400-W, Basf) via an automated doctor blade technique followed by a drying step.…”

The energy performance improvement of a PEM fuel cell with various chaotic flowing channels

“…The proton conductivity of the electrolyte membrane and the activity of the catalyst is highly dependent on the temperature. The operating temperature of low‐temperature PEMFCs should be controlled in 60°C to 70°C, while the working temperature of high‐temperature PEMFCs is about 100°C to 200°C . Higher temperatures can increase the rate of electrochemical reaction and diffusion .…”