KR-102959845-B1 - Coating system and Method for Fuel Cell Separators

KR102959845B1KR 102959845 B1KR102959845 B1KR 102959845B1KR-102959845-B1

Abstract

The objective of the present invention is to provide a coating system and a coating method that increase productivity while satisfying the required physical properties of a fuel cell separator. In accordance with the above objective, the present invention provides a fuel cell separator plate coating system that installs an ion source and a sputter source in a single process chamber, configures a jig capable of mounting a plurality of separator plates loaded into the chamber, and installs a heater in the chamber to heat the separator plates before the deposition process, thereby performing plasma cleaning using an ion source, heating of the substrate using a heater, supplying gas through the ion source and sputter source, and forming a Ti/TiN coating layer using a sputter source.

Inventors

홍정기
홍인기
임우종
정민경
남정우

Assignees

주식회사 이노션테크

Dates

Publication Date: 20260511
Application Date: 20250619

Claims (9)

As a fuel cell separator surface coating system, Process chamber; An ion source, a heater, and a sputter source mounted in the above process chamber; A jig capable of mounting a plurality of separator plates loaded into the above process chamber; A gas supply unit that supplies gas to the above-mentioned ion source and sputter source; Power supply; and Includes a control unit; and The above sputter source includes a cylinder target containing Ti, and The above heater includes a spiral heater having an area formed by making a tubular heater spiral, and is arranged in multiple numbers to uniformly heat the separator plate. The above jig is, For double-sided coating of the separator, a single-sided panel surface is provided including a frame in which one side of a square frame slides and then is fixed and tightened so that all sides of the separator can be coated, and The above panel surface is equipped with fixing members at positions corresponding to the size of the separator plates so that a number of separator plates of various sizes can be mounted, The above panel surface includes a conductive film to help apply bias to the separator, and A plurality of jigs are arranged radially within a single chamber, and during the process, the jig equipped with a separator rotates and revolves. The above power supply device supplies power to the ion source, the sputter source, and the heater, and applies a bias voltage to the separator, and The above control unit is, Control the gas supply and power supply and cutoff for initial vacuuming, plasma cleaning, heater ON/OFF, and sputtering processes, but control the heater so that it is not turned ON simultaneously when driving the ion source or sputter source, and For plasma cleaning, an inert gas and power are supplied to the ion source, and a bias voltage is applied to the separator, and With the ion source and sputter source turned off, turn on the heater to heat the separator plate, and Turn off the heater, supply inert gas to the ion source and sputter source, supply power to the sputter source, and apply a bias voltage to the separator to form a Ti layer on the separator, and Maintain the heater in the off state, supply inert gas without supplying power to the ion source, supply power to the sputter source and supply inert gas and nitrogen gas, and control by applying a bias voltage to the separator to form a TiN layer on the Ti layer, A fuel cell separator plate surface coating system characterized by plasma cleaning, heating, Ti layer formation, and TiN layer formation being performed in a one-stop manner.
As a fuel cell separator surface coating system, Process chamber; An ion source, a heater, and a sputter source mounted in the above process chamber; A jig capable of mounting a plurality of separator plates loaded into the above process chamber; A gas supply unit that supplies gas to the above-mentioned ion source and sputter source; Power supply; and Includes a control unit; and The above sputter source includes a cylinder target containing Ti, and The above heater includes a spiral heater having an area formed by making a tubular heater spiral, and is arranged in multiple numbers to uniformly heat the separator plate. The above jig is, It includes a triangular prism having three panel surfaces capable of mounting separator plates, and The central axis of the triangular prism becomes the axis of rotation, multiple triangular prisms are arranged radially within a single chamber, and during the process, a jig equipped with a separator plate revolves and rotates. The above panel surface is equipped with fixing members at positions corresponding to the size of the separator plates so that a number of separator plates of various sizes can be mounted, The above panel surface is equipped with fixing members at positions corresponding to the size of the separator plates so that a number of separator plates of various sizes can be mounted, The above panel surface includes a conductive film to help apply bias to the separator, and The above power supply device supplies power to the ion source, the sputter source, and the heater, and applies a bias voltage to the separator, and The above control unit is, Control the gas supply and power supply and cutoff for initial vacuuming, plasma cleaning, heater ON/OFF, and sputtering processes, but control the heater so that it is not turned ON simultaneously when driving the ion source or sputter source, and For plasma cleaning, an inert gas and power are supplied to the ion source, and a bias voltage is applied to the separator, and With the ion source and sputter source turned off, turn on the heater to heat the separator plate, and Turn off the heater, supply inert gas to the ion source and sputter source, supply power to the sputter source, and apply a bias voltage to the separator to form a Ti layer on the separator, and Maintain the heater in the off state, supply inert gas without supplying power to the ion source, supply power to the sputter source and supply inert gas and nitrogen gas, and control by applying a bias voltage to the separator to form a TiN layer on the Ti layer, A fuel cell separator plate surface coating system characterized by plasma cleaning, heating, Ti layer formation, and TiN layer formation being performed in a one-stop manner.
A fuel cell separator surface coating system according to claim 1 or 2, characterized in that multiple ion sources and sputter sources are installed.
Using the fuel cell separator surface coating system of claim 1 or 2, Vacuum the chamber, Plasma cleaning is performed for 20 to 40 minutes by supplying an inert gas to an ion source at 150 to 250 sccm, applying 350 to 450 mA, and applying a bias voltage of 0 to 800 V to a jig. Heating at 150 to 250°C for 30 to 90 minutes using a heater, and Inert gas is supplied at 200 to 300 sccm through an ion source and a sputter source, a bias voltage of 50 to 600 V is applied to the jig, a current of 10 to 40 A is applied to the sputter source, and a Ti layer is formed for 7 to 20 minutes. A method for forming a coating material of a separator plate, characterized by supplying an inert gas at a rate of 200 to 300 sccm through an ion source and a sputter source, supplying nitrogen through a sputter source, wherein the supply composition ratio of inert gas to nitrogen is controlled in the range of 5.5:1 to 4:1, applying a bias voltage of 50 to 600 V to a jig, applying a current of 10 to 40 A to a sputter source, and forming a TiN coating layer for 20 to 60 minutes.
A method for forming a coating material of a separator plate according to claim 4, characterized in that when supplying an inert gas during the formation of a Ti layer and a TiN layer, the ratio of the supply amount through a sputter source to the supply amount through an ion source is 1:1 to 1.2:1.
A method for forming a coating material of a separator plate according to claim 4, characterized in that when forming a TiN layer, the ratio of the amount of nitrogen supplied to the amount of inert gas supplied through a sputter source is 67~73:27~33.
In paragraph 4, in forming the TiN layer, A method for forming a coating material of a separator plate, characterized by supplying an inert gas at 200 to 300 sccm through an ion source and a sputter source, and supplying nitrogen at 40 to 70 sccm through a sputter source.
A method for forming a coating material on a separator plate according to claim 4, characterized by performing polishing on the separator plate before performing plasma cleaning.
A method for forming a coating material of a separator according to claim 5, characterized in that 0 to 32V is applied to an ion source when forming a Ti layer and a TiN layer.

Description

Coating system and method for fuel cell separators The present invention relates to a coating system and a coating method for a separator plate for a fuel cell. Fuel cell separators are key components in the manufacturing of electrolytic electric vehicles, fuel cell ships, and fuel cell regional power plants. Fuel cell separators must be conductive and possess both corrosion resistance and wear resistance. In other words, since they must simultaneously possess electrochemical performance, corrosion resistance, and wear resistance while also being cost-competitive, it is desirable to surface-treat a low-cost base material with a coating material that has the desired properties. If stainless steel is selected as the metal base material, TiN can be considered as the coating material. The coating process must also ensure productivity and cost competitiveness. Registered Patent No. 10-1446411 describes a technology for completing the coating layer of a fuel cell separator plate by applying a metal nitride coating to a stainless steel substrate using a metal arc and then applying a carbon coating using an ion source. The aforementioned publication describes an inline system in which separate chambers are configured for each coating and arranged in a row. Installing multiple process chambers and process equipment presents problems such as increased equipment costs and a larger equipment footprint. It is necessary to provide a solution that can further lower the manufacturing cost of fuel cell separators and increase process productivity while still meeting the required physical properties of the fuel cell separators. Figure 1 is a photograph showing a Ti/TiN coating layer according to the present invention. FIG. 2 is a jig design used for coating a separator plate in the present invention. Figure 3 is a table summarizing the physical properties of the coating material according to the present invention. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Figure 1 is a photograph showing a Ti/TiN coating layer according to the present invention. The base material of the fuel cell separator is stainless steel, and Ti is coated as an intermediate layer or buffer layer, and a TiN coating layer is formed thereon. The TiN coating layer, which has excellent surface roughness, provides electrical conductivity, corrosion resistance, high hardness, and durability to the fuel cell separator. Accordingly, the surface of the fuel cell separator requires a hardness of 1700 Hv, a coating adhesion strength of 15 N, a surface roughness of 0.8 µm or less, and a coating layer thickness of 3 µm or less. For such surface treatment, the present invention performs polishing, plasma cleaning (etching), formation of a Ti buffer layer, and formation of a TiN coating layer on the separator plate. Since excellent surface roughness of the coating layer enhances corrosion resistance, the surface of the separator is first mechanically polished with a polishing material such as silicon carbide. Stainless steel separator plates are available in various sizes. There are fixing holes at each corner of the rectangular separator plates. Accordingly, a jig to secure the separator plates is designed. FIG. 2 is a jig design used for coating the separator plate (10) in the present invention. The jig installs fixing parts (20) aligned with the corner fixing holes of the separator plates so that multiple separator plates (10) can be fixed to a single panel. The fixing parts (20) are installed at positions that can be aligned with both the fixing holes of the small separator plates and the fixing holes of the large separator plates. On the right side of FIG. 2, it can be seen that the fixing parts (20) are installed on a geometric shape resembling the letters E, H, and H displayed sideways. Six small separator plates can be fixed to a single jig panel, and two large separator plates can be fixed. Coating as many separator plates as possible in a single coating process can lower production costs. Accordingly, the jig panel is formed into a triangular prism, and the central axis of the triangular prism is made rotatable. In addition, multiple (5 to 7) triangular prisms are arranged radially with respect to the center of the bottom surface of the chamber, and the entire jig is made to revolve around the bottom surface of the chamber. That is, the separator plates revolve during the process. In addition, a conductive film is attached to the panel of the jig and a separator is fixed thereon so that a bias voltage is efficiently applied to the separator. When the separator plates fixed to the jig are loaded into the chamber in this manner, the interior of the chamber is vacuumed, and plasma cleaning, the formation of a Ti buffer layer, and the formation of a TiN top layer are performed. Both an ion source and a sputter source are installed in the process chamber, and one or more of each