本文主要建立PEMFC燃料電池二維、穩態及等溫的單電池模型，討論陰極氣體擴散層及觸媒層兩部分建立其數學模型及邊界條件，來探討不同區域下所產生的來源項和改變操作及性能參數的影響。 觸媒層的探討部分，主要是探討電化學反應中氧氣的傳遞和反應現象產生的電流、電位分布，電化學反應是使用Bulter-Volmer方程式來描述；進而考慮觸媒層的組成成分和效能，觸媒層包含碳、離子體及白金，故考慮白金在觸媒層的比例，對於效能的增加與成本的降低有一定的影響。 氣體擴散電極是以多成分模式來考慮，主要成分有氮氣、氧氣及水蒸氣，探討氧氣與水蒸氣在多孔性電極的分布。擴散電極的原理是提供一個大的反應區域，使得作用物的接近和生成物的移動，所受的質傳障礙量降到最小。故考慮孔隙率、相對溼度及液態水的形成等，改變這些操作與性能參數來了解其對電池性能的影響。 A theoretical model of fluid flow, electrochemistry and mass transport is presented to examine the effect of pressure, velocity and current density in the cathode of proton exchange membrane fuel cells. The finite volume method is applied to simulate the electrode and catalyst layer. Transport in the gas-diffusion electrodes is modeled using the continuity, darcy’s law and concentration equations to calculate pressure, velocity and concentration. Transport in the catalyst layer is modeled using the governing equations to calculate overpotential, current density and reactant concentration. Using the model, influences of various parameters such as pressure, electrode porosity, catalyst porosity, overpotential, proton conductivity, and catalyst surface area on the performance of cathode are quantitatively studied. The influences of parameters on predicted cell performance are also discussed.
