Bipolar plate having a variable width of the reaction channels in the inlet region of the active region, fuel cell stack and fuel cell system having bipolar plates of this type, as well as a vehicle

Abstract

In order to provide a bipolar plate (10) for a fuel cell having two profiled separator plates (12, 14) designed in such a way that the bipolar plate (10) has separate channels (28, 30, 32) for the reaction gases and the coolant, wherein the gas composition is incorporated in the active region, according to the invention, the channels (28, 32) for a reaction gas or both reaction gases have a smaller width (B2) in an inlet region (34) of the active region (16) than in the remaining sub-region (36) of the active region (16), wherein the width (B2) thereof continuously increases from the beginningto the end of the inlet region (34), while supports (54) between the channels (28, 32) have a greater width (B1) than in the remaining sub-region (36) of the active region (16), wherein the sum of the width (B2) of the channels and the width (B1) of the supports (54) is constant, and the width (B2, B2) of the channels (28, 32) and the supports (54) is constant in the entire remaining sub-region (36). The invention also relates to a fuel cell stack, a fuel cell system and a vehicle.

Description

technical field [0001] The invention relates to: a bipolar plate for a fuel cell, said bipolar plate having two profiled diaphragm plates, said two profiled diaphragm plates each having an active area and two distribution areas, For the introduction of reactive gas and coolant to or from the active area, wherein the diaphragm plate is configured such that the bipolar plate has separate channels for reactive gas and coolant, the channels are used for The ports of the reaction gas and the coolant in the two distribution areas are connected to each other, and the channels are respectively configured as open groove-shaped channel structures, wherein the two profiled diaphragm plates are arranged overlappingly such that adjacent A coolant channel is shaped by a channel structure; a fuel cell stack; a fuel cell system; and a vehicle. Background technique [0002] Fuel cells use the chemical conversion of fuel and oxygen into water to generate electricity. For this purpose, the f...

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Problems solved by technology

[0005] In order to control the water supply with respect to the reaction gases in the bipolar plates and thus to increase the power density, efficiency and service life of the fuel cell, it has been proposed inter alia in WO 2012 / 143781 A1 and US 20090197134 A1: a plurality of metals consisting of titanium Strips are introduced into the channel for the reaction gas to be wetted, however this is expensive and also expensive in terms of manufacture, since these metal strips can be difficult to fix and position; or perforated metal plates are introduced into the channel , which is also expensive and expensive to manufacture

Furthermore, these solutions cannot be applied in combination with graphite bipolar plates

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