Novel Porous-Transport-Layers for Fuel Cells and Clean Energy Applications

多孔传输层或气体扩散层(GDL)是聚合物电解质燃料电池(PEFC)的关键组件，PEFC是通过将碳纤维编织成碳布或将碳纤维压在一起制成碳纸，然后通过用疏水乳液完全饱和毛孔来实现防潮。PEFC通过氢气和氧气反应产生电力，水是PEFC唯一的副产品，使其成为下一代汽车和无人机的清洁电力解决方案，以减少温室气体排放。然而，GDL的耐用性很差，因为它们容易发生液态水注入，而且燃料电池组的成本阻碍了它们在零排放汽车和无人机中的广泛采用。为了进一步降低成本，使燃料电池堆在商业上可行，需要具有成本效益和耐用的GDL。拟议的研究方案为使用最先进的添加剂制造技术(3D打印)设计和开发用于PEFC和相关清洁能源应用的新型GDL引入了创新概念，开发了表征GDL的实验方案，并提供了对水滴生长和从其表面分离的更深层次的实际了解。该项目旨在将实验表征和诊断与先进的数学模型相结合，以分析通过新设计的GDL的水分传输，并优化其性能，以实现比对流GDL更好的水分去除和更高的耐久性。主要工作将包括以下方面：(I)利用添加剂制造技术设计和制造具有选择性润湿性能和表面结构的GDL；(Ii)GDL表面形貌、粗糙度、附着力和突破压力的表征以及水滴的生长和脱离GDL的分析；(Iii)开发计算模型来模拟水滴与GDL表面的界面作用；(Iv)修改现有的PEFC模型并纳入界面模型数据以优化GDL；(V)使用现场燃料电池性能测试来验证GDL的实际使用性能。新型GDL将通过提高电池的耐用性和性能，并在燃料电池组件的大规模生产过程中减少制造时间和材料浪费，来降低燃料电池汽车和无人机的成本。由于许多已知的燃料电池技术已在北美、亚洲和德国开发，并通过许可协议在英国获得，拟议中的项目将为英国提供一个独特的机会，使其成为定制GDL的领导者，并成为汽车和无人机应用的下一代燃料电池开发的先驱。

Porous transport layers or gas-diffusion layers (GDLs) are the key component of polymer electrolyte fuel cells (PEFCs), which are made by weaving carbon fibres into a carbon cloth or by pressing carbon fibres together into a carbon paper and then rendered wet-proof by fully saturating the pores with a hydrophobic emulsion. PEFCs produce electric power by reacting hydrogen with oxygen with water as its only by-product, making them a clean power solution for next-generation vehicles and drones to reduce greenhouse gas emissions. However, GDL's poor durability, as they are prone to liquid-water flooding, and the cost of fuel-cell stacks hinder their widespread adoption in zero-emission vehicles and drones. Further cost reduction for making fuel-cell stack commercially viable requires cost-effective and durable GDLs. The proposed research programme introduces innovative concepts to the design and development of novel GDLs for PEFCs and related clean energy applications using state-of-the-art additive manufacturing techniques (3D printing), developing experimental protocols for characterising GDLs, and providing a deeper practical understanding of water-droplet growth and detachment from their surfaces. This project aims to combine experimental characterisation and diagnostics with advanced mathematical modelling to analyse water transport through newly designed GDLs and to optimise their properties for better water removal and higher durability than convectional GDLs. The key work will include the following areas: (i) design and fabrication of GDLs with selective wetting properties and surface structures using additive manufacturing techniques; (ii) characterisation of GDL's surface morphology, roughness, adhesion force, and breakthrough pressure and analysis of water-droplet growth and detachment from GDL; (iii) development of a computational model to simulate interfacial interactions between water-droplets and GDL surface; (iv) modification of an existing PEFC model and incorporation of the interfacial model data to optimise GDLs; (v) validation of GDL's real life performances using in-situ fuel cell performance testing. The novel GDLs will reduce the cost of fuel-cell vehicles and drones by improving the cell durability and performance, and reducing manufacturing time and material waste during the mass production of fuel-cell components. As many of the known fuel cell technologies have been developed in North America, Asia and Germany and acquired in the UK by license agreement, the proposed project will provide a unique opportunity for the UK be the leader in tailored GDLs as well as be the precursor in the development of next-generation fuel cells for vehicle and drone applications.