Formulation of Interconnect of Fuel Cell

Abstract

A formulation of an interconnect of a fuel cell includes chrome powder and chrome-iron alloy powder. A ratio of a sum of chrome in the chrome powder and the chrome-iron alloy powder is in a range between 80% in weight and 95% in weight, and a ratio of a sum of iron in the chrome powder and the chrome-iron alloy powder is in a range between 5% in weight and 20% in weight.

Claims

1. A formulation of an interconnect of a fuel cell, comprising chrome powder and chrome-iron alloy powder, wherein a ratio of a sum of chrome in the chrome powder and the chrome-iron alloy powder is in a range between 80% in weight and 95% in weight.

2. The formulation of claim 1, wherein a ratio of a sum of iron in the chrome powder and the chrome-iron alloy powder is in a range between 5% in weight and 20% in weight.

3. The formulation of claim 1, wherein the chrome-iron alloy powder is stainless steel powder.

4. The formulation of claim 1, wherein a ratio of iron in the chrome-iron alloy powder is in a range between 5% in weight and 30% in weight.

5. A formulation of an interconnect of a fuel cell, comprising chrome powder, iron powder and chrome-iron alloy powder, wherein a ratio of a sum of chrome in the chrome powder, the iron powder and the chrome-iron alloy powder is in a range between 80% in weight and 95% in weight.

6. The formulation of claim 5, wherein a ratio of a sum of iron in the chrome powder, the iron powder and the chrome-iron alloy powder is in a range between 5% in weight and 20% in weight.

7. The formulation of claim 5, wherein the chrome-iron alloy powder is stainless steel powder.

8. The formulation of claim 5, wherein a ratio of iron in the chrome-iron alloy powder is in a range between 5% in weight and 30% in weight.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0010] The present invention will be best understood by referring to the following detailed description of some illustrative embodiments in conjunction with the accompanying drawings, in which

[0011] FIG. 1 is a block diagram of a preferred embodiment of the present invention;

[0012] FIG. 2 is a sketch diagram of the preferred embodiment of the present invention, showing the components of the first interconnect; and

[0013] FIG. 3 is a sketch diagram of the preferred embodiment of the present invention, showing the components of the second interconnect.

DETAILED DESCRIPTION OF THE INVENTION

[0014] FIG. 1 shows a process of manufacturing an interconnect of a fuel cell, including preparing a metal powder mixture, compressing the metal power mixture to form a half-finished product, heating the half-finished product to form an interconnect member, and proceeding surface treatment to the interconnect member to obtain an interconnect. A composition of the metal powder mixture includes chromium (Cr) and iron (Fe), and a temperature of heating the half-finished product is equal to or higher than 1,350 C.

[0015] As shown in FIG. 2, a formulation of the metal powder mixture of a first interconnect includes chrome (Cr) powder 10 and chrome-iron (CrFe) alloy powder 20. The metal powder mixture is compressed and heated as described above to form the first interconnect member, and then the first interconnect member is coated with an alloy layer 30 on a surface thereof to obtain the first interconnect.

[0016] The iron is provided by chrome-iron (CrFe) alloy powder 20. In spite of the components of the metal powder mixture other than chrome (Cr) powder 10 and chrome-iron (CrFe) alloy powder 20, a ratio of a sum of chrome (Cr) is in a range between 80% in weight and 95% in weight, and a ratio of a sum of iron (Fe) is in a range between 5% in weight and 20% in weight.

[0017] Chrome is provided by both the chrome (Cr) powder 10 and the chrome-iron (CrFe) alloy powder 20 and iron is provided by the chrome-iron (CrFe) alloy powder 20 instead of iron powder.

[0018] As shown in FIG. 3, the metal powder mixture of a second interconnect includes chrome (Cr) powder 10, iron (Fe) powder 40, and chrome-iron (CrFe) alloy powder 20. The metal powder mixture is compressed and heated as described above to form a second interconnect member, and then the second interconnect member is coated with an alloy layer 30 on a surface thereof to obtain the second interconnect.

[0019] In spite of components of the metal powder mixture other than chrome (Cr) powder 10, iron (Fe) powder 40 and chrome-iron (CrFe) alloy powder 20, a ratio of a sum of chrome (Cr) is in a range between 80% in weight and 95% in weight, and a ratio of a sum of iron (Fe) is in a range between 5% in weight and 20% in weight.

[0020] Chrome of the second interconnect is provided by both the chrome (Cr) powder 10 and the chrome-iron (CrFe) alloy powder 20 and iron is provided by the iron (Fe) powder 40 and the chrome-iron (CrFe) alloy powder 20.

[0021] The conventional interconnect is made by chrome (Cr) powder and iron (Fe) powder, and the present invention provides chrome-iron (CrFe) alloy powder instead, which may have an easier heating procedure and have a stabilized properties of the interconnect after heating.

[0022] Since a range of the operating temperature of the interconnect is very large, the SOFC will be damaged if a coefficient of thermal expansion of the interconnect is not compatible to other related elements of SOFC. For example, a coefficient of thermal expansion of yttria stabilized zirconia (YSZ), which is widely used in SOFC, is in a range between 1010.sup.6/ C. and 1110.sup.6/ C. A ratio of iron in the chrome-iron alloy powder is in a range between 5% in weight and 30% in weight, and a coefficient of thermal expansion of the interconnect of the present invention is in a range between 910.sup.6/ C. and 1310.sup.6/ C., which is very closed to the conventional yttria stabilized zirconia (YSZ).

[0023] Besides, the chrome-iron (CrFe) alloy powder is cheaper and easier to get, which is helpful to cost down. In an embodiment, the chrome-iron (CrFe) alloy is stainless steel powder.

[0024] The present embodiment defines a relative ratio of chrome and iron in the interconnect. The interconnect may have components other than chrome and iron, but the relative ratio of chrome and iron will not change.

[0025] It must be pointed out that the embodiments described above are only some preferred embodiments of the present invention. All equivalent structures which employ the concepts disclosed in this specification and the appended claims should fall within the scope of the present invention.