Lifetime prediction for the hydrogen–air fuel cells

Abstract

Degrading of membrane-electrode assemblies of hydrogen-air fuel cells during their long term and accelerated stress testing is analyzed by complex of electrochemical and structural methods. In both test ing types, the principal degrading factor is the cathode catalyst destruction accompanied by the active surface loss due to the platinum oxidation, its particles' coarsening, and platinum ion transfer to polymer electrolyte. The approach to membrane-electrode assembly state evaluation during the long term testing on basis of the accelerated stress testing is validated. A method of the lifetime prediction for fuel cells operating in various conditions, differing in temperature, current load and regime, as well, as the membrane-electrode assembly architecture, is suggested.

The Study of the Solid Polymer Electrolyte Oxygen Concentrator with Nanostructural Catalysts Based on Hydrophobized Support

“…The experimental IV curves of the oxygen pump were processed with the use of a simple model, which provide the separation of polarization, ohmic, and diffusion losses and is frequently used to analyze the IV curves of SPE fuel cells and water electrolyzers [29–31] and, in the case of an oxygen pump, is expressed by the equation where U U_OP is the cell voltage, V; E 0 is the equilibrium potential, B; η act is the electrochemical MEA voltage losses, V; η conc is the concentration losses, V; i is the current density, A/cm 2 ; and R tot is the total OP resistance, Ω cm 2 . The equilibrium potential E 0 was calculated by the Nernst equation [ 32 ]. The anode and cathode were combined into a single effective electrode, and the electrochemical losses η act of a fuel cell were calculated by the Tafel equation [ 30 ] where α is the effective transfer coefficient with correction for the number of electrons transferred during the rate-determing step of the slowest reaction, and i 0 is the exchange current density, A/cm 2 .…”

Cost-Optimal Energy Management of Hybrid Electric Vehicles Using Fuel Cell/Battery Health-Aware Predictive Control

“…a) Catalyst layer degradation [33]: electrochemical active surface area (ECASA) reduction occurs, owing to agglomeration, sintering together, and detachment of platinum particles [33], [43], oxidation of carbon support caused by fuel starvation at high or transient loading [44]- [47], production of surface oxides at very low loading [48]. It can be seen that the PEMFCS operating condition has a substantial influence on ECASA reduction.…”

The Effect of Fuel Cell and Battery Size on Efficiency and Cell Lifetime for an L7e Fuel Cell Hybrid Vehicle

“…This enables this work to numerically compare how varying sizes of fuel cell and battery affect the efficiency, range, durability, and the operating cost. These criteria have been selected based their particular importance to zero carbon transportation, due to the high cost of fuel cells [53][54][55], and their below target reliability [5,[56][57][58], which are two critical obstructions to the mainstream commercialization of FCHEVs.…”

“…Conversely, low current densities, resulting in high cathode potentials, can increase the concentration of surface oxides on the catalyst particles. The particles will tend to agglomerate when subsequently reduced [58] causing further, permanent, ECASA reduction.…”