US-20260128328-A1 - SEPARATOR FOR A FUEL CELL

US20260128328A1US 20260128328 A1US20260128328 A1US 20260128328A1US-20260128328-A1

Abstract

A separator for a fuel cell includes: an upper separator including first land portions and brought into close contact with an anode and a cathode of the fuel cell, and a lower separator coupled to the upper separator to form coolant passages. The lower separator has a serpentine structure including second land portions, similar to the upper separator. The first land portions of the upper separator and the second land portions of the lower separator are coupled to each other to form distribution passages, and the distribution passages link up with the coolant passages nearby.

Inventors

Jae Hyeon Choi
Dong Gyu Seo
Kyong Tae Lee

Assignees

HYUNDAI MOTOR COMPANY
KIA CORPORATION

Dates

Publication Date: 20260507
Application Date: 20250107
Priority Date: 20241105

Claims (13)

1 . A separator for a fuel cell, the separator comprising: an upper separator brought into close contact with an anode and a cathode of the fuel cell and including first land portions; and a lower separator coupled to the upper separator to form coolant passages, wherein the lower separator has a serpentine structure including second land portions, wherein the first land portions of the upper separator and the second land portions of the lower separator are coupled to each other to form distribution passages, and the distribution passages are configured to connect to the coolant passages.
2 . The separator of claim 1 , wherein the distribution passages comprise: a first distribution passage comprising: a first passage provided in a first land portion of the first land portions and configured to connect to a first coolant passage of the coolant passages, and a second passage having a first end and a second end that are configured to connect to the first passage; and a second distribution passage provided in a second land portion of the second land portions and configured to connect to the first passage.
3 . The separator of claim 2 , wherein, in the first distribution passage, the second passage partially links up with an adjacent coolant passage among the coolant passages.
4 . The separator of claim 2 , wherein the first passage has a straight shape, and the second passage has a semicircular shape.
5 . The separator of claim 2 , wherein the first passage has a straight shape, and the second passage has a triangular shape.
6 . The separator of claim 2 , wherein the first passage has a straight shape, and the second passage has a rectangular shape.
7 . The separator of claim 2 , wherein the first passage faces the second distribution passage.
8 . The separator of claim 2 , wherein the first passage partially faces the second distribution passage.
9 . The separator of claim 8 , wherein the first passage partially links up with the first and second ends of the second passage such that a gap between a middle portion of the first passage that is not linking up with the second passage and the second distribution passage is reduced.
10 . The separator of claim 1 , wherein the distribution passages include at least one or more distribution passages along a lengthwise direction of the first land portions and the second land portions.
11 . The separator of claim 10 , wherein each of the distribution passages is provided between adjacent coolant passages among the coolant passages, and the distribution passages are on a same line with neighboring distribution passages, among the distribution passages, in a gravity direction.
12 . The separator of claim 10 , wherein the distribution passages are each provided between adjacent coolant passages among the coolant passages, and a distribution passage of the distribution passages is diagonally apart from neighboring distribution passages, among the distribution passages, in a gravity direction.
13 . The separator of claim 1 , wherein the distribution passages are formed at a position adjacent to a coolant diffusion portion into which a coolant is injected while being diffused.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims, under 35 U.S.C. § 119 (a), the benefit of and priority to Korean Patent Application No. 10-2024-0154827, filed on Nov. 5, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to a separator for a fuel cell. More particularly, the present disclosure relates to a fuel cell separator configured to ease the movement of a coolant flowing through multiple passages and diffusion portions. BACKGROUND Generally, a fuel cell is a type of power generator that converts chemical energy of fuel into electric energy through an electrochemical reaction in a fuel cell stack. Fuel cells have a wide range of applications, including serving as industrial power generators, serving as household power generators, powering vehicles, and powering small electronic devices such as portable devices. In recent years, fuel cells have increasingly been used as high efficiency clean energy sources. A typical fuel cell stack has a membrane electrode assembly (MEA) located at the innermost portion thereof. The MEA includes a polymer electrolyte membrane (PEM) allowing transport of hydrogen ions (protons) there through, and catalyst layers (i.e., an anode and a cathode) applied on opposite surfaces of the PEM to cause hydrogen and oxygen to react. Further, gas diffusion layers (GDLs) are laminated outside of the MEA where the anode and the cathode are located, and separators each having a flow field for supplying fuel and discharging water generated by reactions in the MEA are respectively located outside of the GDLs with gaskets interposed there between. End plates are assembled to the outermost portion of the MEA to structurally support and secure individual components described above in position. Thus, at the anode of the fuel cell stack, an oxidation reaction in which hydrogen is oxidized takes places to generate hydrogen ions (protons) and electrons, and the generated protons and electrons flow to the cathode through the PEM and a wire, respectively. At the cathode, water is generated through an electrochemical reaction involving the protons and the electrons that have flowed from the anode, and oxygen contained in air, and this flow of electrons generates electricity. Meanwhile, the separators are generally manufactured such that lands serving as supports and channels serving as flow paths of a fluid are alternately repeated. In other words, a typical separator has a structure in which lands and channels (flow paths) are alternately repeated in a serpentine configuration. Owing to this structure, a channel on one side of the separator, which faces the GDL, is utilized as a space through which reactant gases such as hydrogen or air flows, while a channel on the other side is utilized as a space through which a coolant flows. Accordingly, a single unit cell may have a pair of separators, namely one separator with a hydrogen/coolant channel and the other separator with an air/coolant channel. In such a typical separator, multiple channels are arranged symmetrically to each other, and thus, after the initial coolant flows in, it is difficult for it to move to other straight channels and diffusion portions nearby, so the distribution deviation of the coolant in the channels and diffusion portions increases, which may cause a pressure difference. The above information disclosed in this Background section is provided only to enhance understanding of the background of the present disclosure, and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. SUMMARY The present disclosure has been made in an effort to solve the above-described problems associated with the prior art, and an object of the present disclosure is to provide a separator for a fuel cell having a structure in which an upper separator having semicircular passages and a lower separator having straight passages are coupled to each other to form, on land portions, distribution passages linking up with coolant passages, allowing a coolant to be selectively distributed along the distribution passages to coolant passages nearby to reduce the distribution deviation in the coolant passages and diffusion portions, thereby reducing a differential pressure that may occur when the coolant passes through the coolant passages. In one aspect, the present disclosure provides a separator for a fuel cell. The separator includes: an upper separator brought into close contact with an anode and a cathode of the fuel cell and including upper land portions (i.e., first land portions); and a lower separator coupled to the upper separator to form coolant passages. In particular, the lower separator has a serpentine structure including second land portions (i.e., second land portions), similar to the upper separator. In one embodiment, the first land portions of the upper separator and the second