Fuel Cell Separator Plate Having Controlled Fiber Orientation and
This technology is both a new fuel cell separator plate made of robust composite materials and a method of manufacturing said separator plate. The technology can be used in proton exchange membrane (PEM) fuel cells and has specific relevance to vehicular applications.
Description/Details
This technology represents the next generation in fuel cell innovations.
The technology relates to PEM fuel cells, more specifically to a composite separator plate with oriented fibers, and low-carbon and high-polymer loading. The separator plate composition includes a percentage of conductive fibrous filler having a relatively high aspect-ratio oriented through the thickness of the plate to achieve desired electrical and thermal conductivity requirements.
A method of manufacturing the fuel separator plate having such fibers disposed in a through-plane orientation has also been developed. The method includes forming a separator plate having a land height for orienting the fibers in a desired through-plane direction, then removing a portion of the land height to obtain the desired geometric configuration for the separator plate.
In addition to describing a method of manufacturing, PEM fuel cells are designed to enhance the electrical and thermal conductivity of the fuel cell separator plate.
Separator plates of this composition survive the corrosive fuel cell environment and, for the most part, meet cost and conductivity standards. However, due to the high graphite loading and the high specific gravity of graphite, these plates are inherently brittle, yielding less than desired volumetric and gravimetric stack power densities.
Therefore, it is desirable to provide a fuel cell separator plate formed of a robust composite material having adequate electrical and thermal conductivity properties. Additionally, it is also quite useful to have an efficient method of manufacturing such fuel cell separator plates.
Applications
Fuel cell technologies have been proposed as a power source for many applications. PEM fuel cells operate at relatively low temperatures (about 175° F or 80º C), have high power density, can vary their output quickly to meet shifts in power demand, and are suited for applications -- such as in automobiles -- where quick startup is required. Automobiles: The fuel cell is an environmentally sound alternate to the internal combustion engine. Public Transportation: Subway cars, transit buses, "people movers" and taxis would all benefit from improved fuel cell efficiency. Portable Power: Ideal for portable electronic devices such as laptop computers and cellular phones.
Benefits
The method of manufacture and the material used in this separator plate address some of the problems currently encountered in the fuel cell manufacturing field such as poor conductivity and brittleness of the plate. Better Functionality: Enhances electrical and thermal conductivity of fuel cell plates and provides improved ductility in fuel cells. Robust materials: Stimulating molders/compounders Reduces Cost: Use of low fiber concentrations reduces costs, weight, volume and thickness of fuel cells.