1. Field of the Invention
This invention relates to a fuel cell having composite bipolar plates. Particularly, it relates to a fuel cell having composite plastic and metal bipolar plates. It can significantly reduce the manufacturing cost. Its anti-corrosion capability is excellent. And, it can produce fuel cells having complicated bipolar structures.
2. Description of the Prior Art
The conventional bipolar plates are made by carbon. This kind of carbon-carbon bipolar plates has an excellent electricity generating function. If the bipolar plates are made by specific metal, the bipolar plates can be manufactured by rolling, forging, precision forging, powder metallurgy, etc. In addition, if the bipolar plates are made by a plastic material (having poor strength and poor electrical conductivity), its manufacturing method at least has injection molding, heat-pressing, etc. However, they still have the following disadvantages or problems:
[1] The manufacturing cost is high. Regarding the conventional carbon-carbon bipolar plates, it has excellent electricity generating performance, but the cost is too high. Assuming the cost for one single bipolar plate is roughly around several hundred US dollars, the cost of the fuel cell stack containing ten pair of bipolar plates will reach several thousand US dollars. However, the electricity generated by the conventional fuel cell is quite low (not proportional to its high cost). Therefore, it is hard to compete with others in a commercial market. And, it is very difficult to promote the fuel cell and make it popularized.
[2] It is easy to be corroded. If the bipolar plates are made by metal, it is very easy to be corroded by the water generated inside the fuel cell. Thus, it will influence its flowing smoothness in the channel inside the fuel cell. Furthermore, it might cause the electricity generating unstable or reduce its using life.
[3] It cannot manufacture a fuel cell with complicated bipolar plates. When the bipolar structures are very complicated, its manufacturing process is complex and time-consuming, no matter it is made by carbon-carbon bipolar plates or by pure-metal bipolar plates. So, it is not suitable for mass production.
The primary object of the present invention is to provide a fuel cell having composite bipolar plates that can significantly reduce the manufacturing cost.
The next object of the present invention is to provide a fuel cell having composite bipolar plates. In which, its anti-corrosion capability is excellent.
Another object of the present invention is to provide a fuel cell having composite bipolar plates. It can produce fuel cells having complicated bipolar structures.
In order to achieve the above-mentioned objects, the present invention is provided. A fuel cell having composite bipolar plates comprising a pair of bipolar plates, each bipolar plate having a first surface and a second surface, each bipolar plate including:
a conductive plastic plate having a first plastic surface and a second plastic surface, said first plastic surface being disposed on said first surface, said conduction plastic portion comprising:
a metal plate having a first metal surface and a second metal surface, said first metal surface being disposed on said second surface of said bipolar plate, said second metal surface being connected with said second plastic surface.
The present invention is a fuel cell having composite bipolar plates. Referring to FIGS. 1 to 3, this invention comprises a pair of bipolar plates 10. Each bipolar plate 10 has a first surface 101 and a second surface 102. Each bipolar plate 10 includes a conductive plastic plate 20 and a metal plate 30.
About this conductive plastic plate 10, it has a first plastic surface 201 and a second plastic surface 202. The first plastic surface 201 is disposed on the first surface 10l. The conductive plastic portion 20 comprising:
With regard to this metal plate 30, it has a first metal surface 301 and a second metal surface 302. This first metal surface 301 is disposed on the second surface 102 of the bipolar plate 10. The second metal surface 302 is connected with the second plastic surface 102.
Thus, the structure of the bipolar plates is solid and it has a highly electrical conductivity. Also, their mechanical strength and anti-corrosion capability are excellent.
Referring to
As shown in
As illustrated in
Of course, except the above-mention heat-pressing method, the existing injection-molding method can be used. About the bipolar plates of this invention, these methods are suitable for mass production.
The advantages and disadvantages can be summarized as follows:
[1] It can significantly reduce the manufacturing cost. This invention can be made by a low-cost conductive material (the conductive plastic plate) and metal plates via the heat-pressing or injection-mold. It is suitable for mass production and reducing the manufacturing cost.
[2] Its anti-corrosion capability is excellent. In this invention, the bipolar plate is consisted by the conductive plastic plate and the metal plate. More specifically, the electrochemical reaction occurs on the catalytic unit that is positioned between these conductive plastic plates. The metal plate will not be corroded. So, the life of the bipolar plates can be prolonged.
[3] It can produce fuel cells having complicated bipolar structures. The bipolar plates can be manufactured by heat-pressing or injection molding, even though they have very complicated structure formed on the conductive plastic plates. Thus, this invention is suitable for mass production with low manufacturing cost by heat-pressing or injection molding.
The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.
Number | Date | Country | Kind |
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094145113 | Dec 2005 | TW | national |