质子交换膜燃料电池电极局域氧传输机理研究及高通量氧传输电极设计

The development of new energy vehicles requires fuel cells to increase power density, high power density means high output current density, high output current density need to solve the problem of coupling between mass transfer and oxygen reduction reaction. How to improve the mass transfer rate of reactants, reduce the mass transfer polarization, and the coupling between oxygen mass transfer and oxygen reduction reaction are become the key problems to the development of fuel cell technology. The related scientific problems have become the hotspot of fuel cell research. Based on the research of the previous work from Wuhan University of Technology (optimizing the low-platinum high-performance membrane electrode assembly (MEA)), this project will further strengthen the process of oxygen mass transfer in proton exchange membrane fuel cell (PEMFC) and its coupling with oxygen reduction. The formation mechanism of the high-throughput oxygen mass transfer resistance in the electrode, the coupling effect between the oxygen mass transfer and the oxygen reduction reaction on the surface of the catalyst, the proton conduction mechanism of the nano-electrode, and the structure-activity relationship of two phase interface between the ionomer/catalyst, ionomer/water and water/catalyst and its mechanism of influence on proton conductivity and oxygen transmission resistance. This work is provides theoretical guidance for development of the China's next generation Fuel cell stack with high current density.

新能源汽车的发展需要燃料电池提高功率密度，高功率密度意味着高输出电流密度，高输出电流密度需要解决传质及其与氧还原反应耦合问题。如何降低传质阻力、提高反应物传质速率，以及氧传质与氧还原反应耦合成为目前燃料电池技术发展的关键，相关科学问题也成为燃料电池研究热点。本项目拟在武汉理工大学低铂高性能膜电极的研究基础上，深入开展质子交换膜燃料电池氧传质过程强化及其与氧还原反应耦合的基础科学问题研究，揭示电极中高通量氧传质阻力形成机理、催化剂表面氧传质与氧还原反应的耦合效应、纳米电极质子传导机理和离子交换树脂/催化剂、离子交换树脂/水和水/催化剂等几种两相界面之间的构效关系及其对质子传导率、氧传输阻力的影响机制，丰富燃料电池基础理论，为我国下一代高电流密度电堆的研制提供理论指导。

新能源轻型汽车的发展需要燃料电池提高功率密度，高功率密度意味着高输出电流密度，高输出电流密度需要解决传质及其与氧还原反应耦合的问题。本项目在低铂高性能膜电极的研究基础上，深入开展质子交换膜燃料电池氧传质过程强化及其与氧还原反应耦合的基础科学问题研究。建立了气体扩散层中水气传输新模型并修正多孔介质中水饱和度概念，阐明电极中孔隙率、孔径分布、界面结构等因素对高通量氧传输阻力的影响规律，揭示了催化层中Nafion倾向于分布在Pt颗粒表面的现象及其对氧传输的影响。提出电荷转移阻抗作为氧还原活性指示符，并以此评估Pt载量与Nafion毒化效应的相关性。设计制备带裂纹的气体扩散层、阵列超疏水气体扩散电极以及内嵌铂Pt纳米多孔电极。丰富了燃料电池基础理论，为高功率燃料电池膜电极的开发提供新思路。