A Novel Design of Wave-Like PEMFC Stack with Undulate MEAs and Perforated Bipolar Plates P. Y. Yi 1 , L. F. Peng 1 , X. M. Lai 1 *, D. A. Liu 1 , and J. Ni 2 1 State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China 2 Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109-2125, USA Received February 20, 2009; accepted December 11, 2009 1 Introduction Fuel cells are being pursued for a wide variety of applica- tions due to their high theoretical efficiency and environmen- tal friendliness [1, 2]. In particular, proton exchange mem- brane fuel cells (PEMFCs), because of the advantages of low temperature operation, fast start-up, system robustness and low emissions, are attractive for automotive and portable ap- plications [3]. However, commercialisation of PEMFC tech- nology depends on achieving high volumetric power density and specific power for a given cost, so that its characteristics compete cost-effectively with traditionally used energy con- version devices [4]. The US Department of Energy’s (DOE) 2010 technical target for automotive fuel cell power systems operating on direct hydrogen is that volumetric power den- sity is 2,000 W L –1 and specific power is 2,000 W kg –1 for stack [5]. Optimisation the stack architecture and usage of low-cost lightweight material for bipolar plates are two effi- cient ways to improve the fuel cell power density and lower its cost simultaneously. As shown in Figure 1, conventional PEMFC stack designs have been based on planar, repetitively stacked structure that use milled or pressure-moulded plates to deliver fuel and oxi- dant gases to the reaction sites. Nevertheless, some new struc- tural designs for PEMFCs have been proposed for higher power density by modifying the geometries of membrane electrode assembles (MEAs) or bipolar plates in recent years. A micro-tubular fuel cell was developed by NASA to improve the volumetric power density for portable electronic equipments [6]. The MEAs were tubular in shape which could be packed into a small case with oxygen/hydrogen cross flow. This design increased the power density because – [ * ] Corresponding author, xmlai@sjtu.edu.cn Abstract Commercialisation of proton exchange membrane fuel cell (PEMFC) technology depends on high volumetric power density and specific power for a given cost. In the present study, a novel wave-like architecture for PEMFC stack based on undulate membrane electrode assembles (MEAs) and perforated bipolar plates (PBPs) was presented. Different from conventional plate-and-frame architecture, this design increased active area and achieved higher volumetric power density due to undulate MEAs. Moreover, perforated sheet metal was used as bipolar plates so that it could improve specific power. A single cell was designed and fabricated in house to evaluate the performance of the novel architecture stack. Stamped PBPs with open rate of 28.26% and hot pressed 5-layer undulate MEAs with Nafion ® 112 were adopted. The results indicated that the peak volumetric power density and specific power are 2,715.94 W L –1 and 2,157.86 W kg –1 , respectively, while they are 2,151.28 W L –1 and 1,709.22 W kg –1 at the output voltage of 0.6 V. This study may propose a possible means to meet the DOE’s 2010 technical target that volumetric power density is 2,000 W L –1 and specific power is 2,000 W kg –1 for stack. Keywords: PEM Fuel Cell, Perforated Bipolar Plate, Specific Power, Undulate MEAs, Volumetric Power Density FUEL CELLS 10, 2010, No. 1, 111–117 © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 111 ORIGINAL RESEARCH PAPER DOI: 10.1002/fuce.200900031