The Novel Boltless Stack Assembly and Light weight Stack Configuration

Abstract

The intrinsic improvement of fuel cell stack design is to minimize the volume and weight of fuel cell and is to maximize energy density. However, the bulky and massive stack is one of the main factors to undermine the chances to realize the higher energy density. Though the using bolts and graphite bipolar plates are common in a conventional stack, it may obstruct realizing a light weight and thinner stack. In this paper, the graphite bipolar plate is substituted with the flexible PCB and lightweight polycarbonate plates are used to separate the reactant gas. By using the plastic material as a separator, an innovative boltless stack assembly is originally possible through an ultrasonic welding. Instead of the bolt, the sharp edge of one plate melts and adjacent cell plates are bonded by the ultrasonic welding, which realizes the boltless and light weight stack assembly.