质子交换膜燃料电池冷启动时阴极催化层内多场耦合的介孔尺度模型

A Mesoscopic Pore-Scale Model of Multi-Disciplinary Coupling in PEMFC Cathode Catalyst Layer during Cold Start

为详细解析质子交换膜燃料电池(PEMFC)零下温度启动过程,建立了电池冷启动时多场耦合过程的介孔尺度数值模型。几何模型基于随机网格法(SGM)重建的催化层介孔结构,数学模型描述了物质传输、电荷传输、电化学反应和汽-冰相变过程。数值分析了电池冷启动过程中催化层内冰的生成和演化,重点探讨了冰的生成及形貌对电池性能的影响,推导出电化学活性反应面积与结冰量的关系式。

In order to have a deep understanding of the cold start of proton exchange membrane fuel cell(PEMFC)from sub-zero temperature,a mesoscopic pore-scale model of multi-disciplinary coupling in cathode catalyst layer(CL)was established.The geometry model is a 3-dimensional pore-structure of CL reconstructed by the random grid method(SGM),and the species transport,charge transport,electrochemical reactions and phase change of water were described by mathematical model.The formation and evolution of ice in CL during cold start were simulated and analyzed,the effects of ice formation and morphology on battery performance were discussed,and a correlation of the electrochemical active reaction area(ECA)to the amount of ice formation in CL was derived from the simulation results.