ELECTROCHEMICAL FUEL CELL STACK WITH AN IMPROVED COMPRESSIONASSEMBLY

摘要

An electrochemical fuel cell stack with an improved compression assembly comprises a tension member which is electrically non-conductive and preferab ly non--metallic. The tension member can be made from a composite material whic h has similar expansion and contraction properties as the stack materials, thereby reducin g undesirable fluctuations in the compressive force applied to the stack. An improved apparatus for securing the improved tension member to the rest of the compression assembly is also provided. Preferred embodiments of an improved compression assembly employ a collet and wedges to grip the tension member and compress a resilient member which imparts a tensile force to the tension member and a compressive force to the fuel cell assemblies. In other embodiments, an improved compression assembly employs a unitary resilient member and fastener in combination with a tension member. The improved apparatus is easier to assemble in high speed manufacturing processes because the compression assembly can be assembled or installed using the same machinery which is use d to compress the stack in one fixturing because the compression assembly is assembled by being stacked in essentially the same direction as the other fuel cell components. An improved method of assembling a compression assembly for an electrochemical fuel cell stack is also provided.