US-12620612-B2 - Fuel cell stack

US12620612B2US 12620612 B2US12620612 B2US 12620612B2US-12620612-B2

Abstract

The present disclosure relates to a fuel cell stack including a reaction unit comprising a plurality of unit cells and configured to define reaction regions for electrochemical reactions of reactant gases, and manifold blocks disposed at two opposite ends of the reaction unit and provided independently of the reaction unit, the manifold blocks having manifold flow paths for supplying and discharging the reactant gases, thereby obtaining an advantageous effect of simplifying a structure and a manufacturing process and improving safety, maintainability, and reliability.

Inventors

Kyu Hwan Shim

Assignees

HYUNDAI MOTOR COMPANY
KIA CORPORATION

Dates

Publication Date: 20260505
Application Date: 20220628
Priority Date: 20220303

Claims (11)

1 . A fuel cell stack comprising: a reaction unit comprising a plurality of unit cells and configured to define reaction regions for electrochemical reactions of reactant gases; manifold blocks disposed at two opposite ends of the reaction unit and provided independently of the reaction unit, the manifold blocks having manifold flow paths for supplying and discharging the reactant gases and having a coolant flow path; a clamp member disposed to surround the plurality of unit cells and configured to lock the plurality of unit cells; inner endplates configured to cover outer surfaces of the reaction unit; outer endplates configured to cover outer surfaces of the manifold blocks and outer surfaces of the inner endplates and having flow path holes corresponding to the manifold flow paths and having a coolant hole configured to communicate with the coolant flow path; and a coolant port provided on an outer surface at an end of the manifold block and configured to communicate with the coolant flow path; wherein an accommodation portion is provided in an outer surface of the inner endplate, and an end of the clamp member is accommodated in the accommodation portion, wherein an outer surface of the end of the clamp member is disposed on the same plane as the outer surface of the inner endplates in a state in which the end of the clamp member is accommodated in the accommodation portion, wherein a coolant supplied into the fuel cell stack flows through the coolant flow path of the manifold blocks, then passes through flow paths formed between the plurality of unit cells along the stacking direction of the plurality of unit cells, and is discharged, and wherein the coolant port is connected to a central portion of the coolant flow path corresponding to a central portion of the reaction unit along the stacking direction of the plurality of unit cells.
2 . The fuel cell stack of claim 1 wherein the plurality of unit cells are in a stacked arrangement.
3 . The fuel cell stack of claim 1 , further comprising: a manifold side gasket interposed between the outer endplates and an outer surface of the manifold block.
4 . The fuel cell stack of claim 1 , further comprising: an endplate fastening member configured to fasten the outer endplates with the reaction unit interposed therebetween.
5 . The fuel cell stack of claim 1 , further comprising: a stepped portion provided on an inner surface of the outer endplates that faces the reaction unit, the stepped portion being in close contact with the outer surface of the inner endplates.
6 . The fuel cell stack of claim 1 , further comprising: a manifold fastening member configured to fasten the manifold blocks with the reaction unit interposed therebetween.
7 . The fuel cell stack of claim 6 , further comprising: a support block protruding from an outer surface of the manifold block, wherein the manifold fastening member is fastened to the support block.
8 . The fuel cell stack of claim 1 , further comprising: a manifold gasket interposed between the manifold block and the reaction unit.
9 . The fuel cell stack of claim 1 , further comprising: a guide rail provided on any one of the manifold block and the reaction unit; and a guide groove provided in the other of the manifold block and the reaction unit and configured to correspond to the guide rail and accommodate the guide rail.
10 . The fuel cell stack of claim 1 , wherein at least any one of two opposite ends of each of the manifold flow path and the coolant flow path based on a direction in which the unit cells are stacked is opened.
11 . The fuel cell stack of claim 1 , wherein the unit cell comprises: a membrane electrode assembly (MEA); and a separator stacked on the membrane electrode assembly.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is based on and claims under 35 U.S.C. § 119 (a) the benefit of Korean Patent Application No. 10-2022-0027555 filed in the Korean Intellectual Property Office on Mar. 3, 2022, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD Embodiments of the present disclosure relate to a fuel cell stack, and more particularly, to a fuel cell stack capable of simplifying a structure and a manufacturing process and improving safety, maintainability, and reliability. DESCRIPTION OF RELATED ART A fuel cell stack refers to a kind of power generation device that generates electrical energy through a chemical reaction of fuel (e.g., hydrogen), and the fuel cell stack may be configured by stacking several tens or hundreds of fuel cells (unit cells) in series. The fuel cell may include a membrane electrode assembly (MEA) having an electrolyte membrane that allows hydrogen positive ions to move therethrough, and electrodes (catalyst electrode layers) provided on two opposite surfaces of the electrolyte membrane to enable a reaction between hydrogen and oxygen. The fuel cell may also include gas diffusion layers (GDLs) disposed to be in close contact with two opposite surfaces of the membrane electrode assembly and configured to distribute reactant gases and transfer the generated electrical energy, and separators (bipolar plates) disposed to be in close contact with the gas diffusion layers and configured to define flow paths. The separators may include an anode separator configured to supply hydrogen which is fuel, and a cathode separator configured to supply air which is an oxidant. The separator includes channels through which the fuel or the oxidant flows. In addition, manifold flow paths for supplying and discharging reactant gases (e.g., hydrogen and air) and manifold flow paths for supplying and discharging a coolant are disposed at two opposite ends of the separator. However, in the related art, the manifold flow path and the coolant flow path, through which the reactant gas and the coolant are supplied and discharged, need to be directly formed in the separator. For this reason, there is a problem in that a structure of the separator and a process of manufacturing the separator are complicated, and there is also a problem in that it is difficult to reduce a size and weight of the separator to a certain degree or more. Moreover, in the related art, gaskets need to be installed around a reaction region between the stacked separators (reaction regions for electrochemical reactions of the reactant gases) and also need to be installed around the manifold flow path and the coolant flow path to prevent leaks of the reactant gas and the coolant. For this reason, there are problems in that the manufacturing process is complicated, the productivity and production efficiency deteriorate, and costs are increased. Therefore, recently, various studies have been conducted to simplify the structure of the fuel cell stack and the process of manufacturing the fuel cell stack, but the study results are still insufficient. Accordingly, there is a need to develop a technology to simplify the structure of the fuel cell stack and the process of manufacturing the fuel cell stack. SUMMARY Embodiments of the present disclosure have been made in an effort to provide a fuel cell stack capable of simplifying a structure and a manufacturing process and improving safety and reliability. In particular, embodiments of the present disclosure have been made in an effort to provide a fuel cell stack, in which a manifold flow path and a coolant flow path, through which reactant gases and a coolant are supplied and discharged, are independently separated from a separator, and the separator has only a reaction region. Embodiments of the present disclosure have also been made in an effort to simplify a structure of a separator and reduce a size and weight of the separator. Embodiments of the present disclosure have also been made in an effort to improve structural rigidity of a fuel cell stack and stably maintain fastening strength. Embodiments of the present disclosure have also been made in an effort to make it easy to handle (e.g., dismantle or disassemble) a fuel cell stack, simplify processes (maintenance processes) of inspecting and replacing the fuel cell stack, and reduce the time and cost required for the processes. Embodiments of the present disclosure have also been made in an effort to minimize a distribution deviation (flow rate deviation) of reactant gases and ensure stable output performance. The objects to be achieved by the embodiments are not limited to the above-mentioned objects, but also include objects or effects that may be understood from the solutions or embodiments described below. In one aspect, a fuel cell stack is provided comprising: (a) a reaction unit comprising a plurality of unit cells and configured to define reaction regions for electroc