Identifiability Analysis of Degradation Model Parameters from Transient CO2 Release in Low-Temperature PEM Fuel Cell under Various AST Protocols

An Experimental Investigation of the Effect of Platinum on the Corrosion of Cathode Carbon Support in a PEMFC

The possible role of platinum in the carbon corrosion at cell voltage higher than 1.0 V is controversial yet. To gain more insights into this issue, a square-wave potential cycles between 1.0 to 1.5 V was applied to fuel cells comprising cathodes with and without Pt. Using online non-dispersive infrared spectroscopy, we showed that Pt catalyzed the gasification of carbon in the early stage, while upon prolonged exposure to potential cycling (≥3 h), platinum started to hinder the CO₂ production. Based on cyclic voltammetry tests and Raman spectroscopy, the inhibiting effect of platinum on the corrosion was suggested to originate from modifications on carbon surface, where the formation of electroactive sites was limited. Electrode and non-electrode ohmic resistances were distinguished further through electrochemical impedance spectroscopy measurement and the changes in electrode microstructure and surface composition were examined by scanning electron microscope image and energy dispersion X-Ray spectroscopy. The results indicated that Pt reduced the damage of electrode structures after potential cycles.

Thermoelectric Generator as the Waste Heat Recovery Unit of Proton Exchange Membrane Fuel Cell: A Numerical Study

The proton exchange membrane fuel cell (PEMFC) is a prominent environmentally friendly alternative candidate to internal combustion engines in automotive applications. The recovery of the waste heat of light-duty diesel engines has been investigated recently, which is similarly relevant for PEMFCs. Thermoelectric generators (TEG) applied on the stack’s walls have been already proposed and tested as a cooling method for small scale applications of the PEMFC. For the medium scale usages of the PEMFC stack, TEG technology may be further used to recover heat lost through the cooling water required for stack thermal management, which was the focus of the present study. Using an agglomerate model for the PEMFC and a computational fluid dynamic (CFD) thermal model for the TEG heat exchanger unit, the operation and performance of the PEMFC stack and heat recovery unit were simulated, respectively. After validation, results indicated that the transferred heat from the PEMFC to the cooling channel increased the temperature of the coolant from room temperature to 330.5 K at the current density of 0.8 A/cm2. CFD analysis revealed that 37.7 W of the heated wasted by the PEMFC stack could be recovered by the currently available TEG material and geometry.