Design Of Proton Exchange Membrane Fuel Cell Research Articles

Proton Exchange Fuel Cell: The Design, Construction and Evaluation

This work presents the development of a prototype of proton exchange membrane fuel cells (PEMFC). The geometric design and meshing of the PEMFC are described herein. The electrode was fabricated using graphite with flow-field geometry. The PEMFC was tested for 100 hour of continuous work and its performance was evaluated by constant monitoring of the current and voltage produced. In accordance with the results obtained, the most relevant aspects affecting the PEMFC design will be discussed to optimize the performance of the cell.

Coupled modeling of water transport and air–droplet interaction in the electrode of a proton exchange membrane fuel cell

In this work, an accurate and computationally fast model for liquid water transport within a proton exchange membrane fuel cell (PEMFC) electrode is developed by lumping the space-dependence of the relevant variables. Capillarity is considered as the main transport mechanism within the gas diffusion layer (GDL). The novelty of the model lies in the coupled simulation of the water transport at the interface between gas diffusion layer and gas flow channel (GFC). This is achieved with a phenomenological description of the process that allows its simulation with relative simplicity. Moreover, a detailed two-dimensional visualization of such interface is achieved via geometric simulation of water droplets formation, growth, coalescence and detachment on the surface of the GDL. The model is useful for optimization analysis oriented to both PEMFC design and balance of plant. Furthermore, the accomplishment of reduced computational time and good accuracy makes the model suitable for control strategy implementation to ensure PEM fuel cells operation within optimal electrode water content.

Single PEMFC Design and Validation for High-Temperature MEA Testing and Diagnosis up to 300°C

A single proton exchange membrane fuel cell (PEMFC) and associated hardware were designed for high-temperature membrane electrode assembly (MEA) testing and diagnosis in the range of . The fuel cell heating strategy and its design considerations with respect to heat balance are also discussed in this paper. The fuel cell performance of PEMEAS -doped polybenzimidazole (PBI)-based MEAs and the corresponding ac impedance diagnosis demonstrated that this single cell and its associated hardware designs are feasible for high-temperature MEA testing. The apparent exchange current densities for the cathodic oxygen reduction reaction as a function of temperature were obtained through ac impedance measurement. Rapid performance degradation was observed at extreme temperatures, such as , suggesting an accelerated fuel cell testing method. AC impedance results showed that the activity loss of the catalyst/catalyst layer was responsible for this degradation.

Effects of two-phase transport in the cathode gas diffusion layer on the performance of a PEMFC

This study investigates the characteristics of transport phenomena in the cathode gas diffusion layer (GDL) of a proton exchange membrane fuel cell (PEMFC) and their influences on cell performance by utilizing a two-phase flow model based on a multiphase mixture formulation. The profiles of liquid water saturation and oxygen concentration across the GDL are obtained by a direct numerical procedure, and the corresponding polarization curves are determined as well. The results show that the liquid water generated by the electrochemical reaction could significantly reduce the effective porosity of the GDL under high current density conditions to hinder oxygen transport through the GDL. The removal rate of liquid water due to capillarity-induced motion can be enhanced conspicuously by an increase in hydrophobicity at first, and this effect then diminishes gradually. The effects of porosity and thickness of the GDL, inlet velocity of reactant gas, and gas channel length on the cell performance are also examined in detail. The results provide insights into the transport mechanisms in the GDL and benefit the design of PEMFCs.

An analytical solution for transport of oxygen in cathode gas diffusion layer of PEMFC

A two-dimensional theoretical model is developed in this study to simulate the transport phenomena of oxygen in cathode gas diffusion layer (GDL) of proton exchange membrane fuel cell (PEMFC). An analytical solution is then obtained accordingly to characterize the effects of GDL on cell performance. It is found that the concentration flux of oxygen across the GDL is primarily dominated by the thickness and porosity of GDL. For a thicker GDL, the diffusion resistance increases and thus lowers the cell performance especially under high current density condition. On the other hand, an increase of porosity will enhance the transport of oxygen and result in significant improvement of cell performance. The influences of system parameters including the temperature, channel height, inlet velocity, and inlet pressure on the diffusion of oxygen in GDL are also examined systematically. Results provide insights into the characteristics of oxygen diffusion in GDL and benefit the optimal design of PEMFC.

연료전지 공기판의 구조적 변형을 고려한 유동 해석과 실험

연료전지의 박막면은 공기판에 비해 변형이 쉬운 재질로 이루어져 있다. 박막면의 구조적 변형에 따라 채널 단면의 형상이 바뀔 수 있고, 채널의 형상이 변하면 유통특성은 크게 달라질 수 있다. 연료전지의 공기판을 설계할 때에 유동 특성은 성능을 좌우하는 중요한 요소이다. 설계된 공기판의 검증을 위해서는 유동 특성을 파악하고, 유동 특성이 효율적인 성능을 갖기 위한 조건을 만족시키는가를 알아보아야 한다. 본 연구에서는 공기판의 유동 특성을 파악하기 위해 유동해석을 수행하였고, 동일한 조건에서의 실험을 수행하여 해석결과를 검증하였다. 그리고 박막면의 구조적 변형에 의한 유동 특성의 변화를 알아보기 위하여 박막면과 공기판의 구조해석을 수행한 결과를 이용하여 박막면의 구조적 변형을 고려한 유동해석을 수행하여 박막면의 구조적 변형을 고려하지 않은 유동해석의 결과와 그 특성을 비교하였다. 그 결과 상당한 차이가 발생함을 알 수 있었다. 연료전지의 설계를 위해 해석 및 실험시 구조변형이 고려되어야 함을 규명할 수 있다. The porous media of a proton exchange membrane fuel cell (PEMFC) is made of deformable materials. The shape of cross sectional area in air plate channels has been changed by structural deformation of the porous media. The uniform mass flow rate and pressure are major factors for safe and efficient operation in the PEMFC. Two kinds of models are provided for the flow analyses. Deformable and undeformable porous media are considered for numerical analysis and experiment of the air plate model. The numerical flow analysis results with deformable and undeformable porous media has some discrepancy in pressure distribution. The pressure differences are measured in order to compare with numerical analysis results. Pressures are measured between inlet and outlet of the air plate. The numerical analysis and experimental results show similar pressure distribution. It is shown that the pressure drops in the two approaches are well matched each other. It is proven that the consideration of structural deformation is required in the numerical analysis/experiment for the PEMFC design.