Fuel cell stack

Abstract

Corrosion of a metal portion such as a pipe connected to a fuel cell stack is suppressed. The fuel cell stack has a plurality of single cells which generate electrical power using an aqueous methanol solution and air and are stacked in a vertical direction. An inlet of a fuel supply manifold for distributing the aqueous methanol solution to each cell and an outlet of a fuel discharge manifold for collecting the fuel discharged from the single cells are provided in a common conductive end plate. Hence, when the discharge fuel discharged from the fuel cell stack is circulated and resupplied to the stack, the potential of the discharged fuel becomes equal to that of the liquid fuel to be supplied to the stack, whereby the corrosion of the metal portion such as a pipe, a tank, a pump, or a heat exchanger is suppressed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which:

FIG. 1 is a schematic diagram showing the general configuration of a fuel cell system employing a fuel cell stack according to an embodiment;

FIG. 2 is an exploded side view showing the configuration of the fuel cell system;

FIG. 3 is an exploded perspective view showing the configuration of the fuel cell system (the viewing direction: from the upper side to the lower side);

FIG. 4 is an exploded perspective view showing the configuration of the fuel cell system (the viewing direction: from the lower side to the upper side);

FIG. 5 is a view showing the structure of a membrane electrode assembly;

FIG. 6 is a perspective view showing a liquid fuel passage provided in the lower surface of a separator (in this perspective view, the viewing direction is from the lower side of the separator to the upper side); and

FIG. 7 is a perspective view showing a liquid fuel passage provided in the upper surface of the separator (in this perspective view, the viewing direction is from the upper side of the separator to the lower side).

Claims

1. A fuel cell stack comprising a stack of a plurality of cells which generate electrical power using a liquid fuel and an oxidant, wherein an inlet portion of a fuel supply manifold which distributes the liquid fuel to each of the cells is electrically connected to an outlet portion of a fuel discharge manifold which discharges discharge fuel discharged from each of the cells.

2. The fuel cell stack according to claim 1, wherein the inlet portion of the fuel supply manifold and the outlet portion of the fuel discharge manifold are provided in any one of a pair of conductive end plates which sandwich the stack of the plurality of cells therebetween with a collector and an insulating body interposed between the stack and each of the end plates.

3. The fuel cell stack according to claim 2, wherein the plurality of cells is stacked in a vertical direction, and wherein the end plate having the inlet portion of the fuel supply manifold and the outlet portion of the fuel discharge manifold provided therein are disposed above the plurality of cell.

4. The fuel cell stack according to claim 2, wherein an inlet portion of an oxidant supply manifold which distributes the oxidant to each of the cells and an outlet portion of an oxidant discharge manifold which discharges the oxidant discharged from each of the cells are provided in the end plate having the inlet portion of the fuel supply manifold and the outlet portion of the fuel discharge manifold provided therein.