Ceramic assembly through metal thin-film deposition

Abstract

The present invention relates to a ceramic assembly comprising: a solid electrolyte made of a ceramic material; a polyolefin-based polymer sealant; a metal support; and a metal layer deposited on a ceramic surface at a bonding interface between the ceramic solid electrolyte and the polyolefin-based polymer sealant.

Description

Ceramic assembly through metal thin film deposition

[0001] The present invention relates to an invention for improving wettability at the interface between a ceramic and a polymer film by depositing a metal layer between the ceramic and the polymer using a metal thin film deposition.

[0002] Typically, bonding between ceramics and polymers is achieved primarily through mechanical interlocking. During this bonding process, if the wettability between the ceramic and polymer is poor, voids can form at the interface, allowing moisture or gas to permeate through the channels created by these voids. Therefore, thermal bonding of ceramics and polymers may not be suitable for systems requiring watertightness. To address this issue, metal can be deposited on the surface of the ceramic membrane to enhance its wettability with the polymer, thereby reducing the voids created during thermal bonding and lowering moisture or gas permeability.

[0003] In order to solve the problem of poor wettability between the two materials, ceramic and polymer, we aim to improve the problem by depositing metal between the two materials, ceramic and polymer.

[0004] The ceramic assembly of the present invention may include a solid electrolyte of a ceramic material, a polyolefin-based polymer, a metal support, and a metal layer deposited on a ceramic surface at a bonding interface between the solid electrolyte of the ceramic material and the polyolefin-based polymer.

[0005] The above metal layer may be an aluminum metal layer.

[0006] A method for manufacturing a ceramic assembly according to one embodiment of the present invention may include a step of depositing an aluminum thin film on an edge of a surface of a Nasicon, a step of bonding the Nasicon and a sealant film through thermal bonding, and a step of bonding a laminate film to the sealant film through thermal bonding.

[0007] The above thermal bonding can be performed under conditions of 180 to 240°C.

[0008] Depositing a metal film on a ceramic surface can improve water-tightness through thermal bonding between the ceramic and polymer. Specifically, improved wettability at the bonding interface can reduce moisture permeability.

[0009] FIG. 1 illustrates an overall diagram of a Nasicon assembly according to one embodiment of the present invention.

[0010] FIG. 2 is a process diagram showing a NASICON assembly in which aluminum is deposited according to one embodiment of the present invention.

[0011] Figure 3 shows a process diagram for manufacturing a cathode according to an example of the present invention.

[0012] Figure 4 shows an AFM result graph of a ceramic surface before and after aluminum metal deposition.

[0013] Figure 5 shows an SEM image of the surface after aluminum metal deposition.

[0014] Figure 6 shows the interface between the Nasicon and the sealant before deposition of the aluminum metal thin film.

[0015] Figure 7 shows the interface between the Nasicon and the sealant after deposition of an aluminum metal film.

[0016] Figure 8 shows the contact angle between pure Nasicon and polypropylene.

[0017] Figure 9 shows the contact angle between Nasicon and polypropylene on which an aluminum metal film has been deposited.

[0018] Figure 10 is a graph showing the change in moisture increase in a seawater secondary battery manufactured using a Nasicon with a thin film of aluminum metal deposited thereon.

[0019] Typically, bonding between ceramics and polymers is achieved primarily through mechanical bonding. Consequently, voids can form at the interface between the two materials, creating channels through which moisture or gas can pass. This is due to poor wetting between the two materials.

[0020] For the above reasons, thermal bonding of ceramics and polymers may not be suitable in systems requiring watertightness.

[0021] However, if the surface of the ceramic is made smooth to prevent moisture or gas penetration, a problem may arise in that the adhesiveness may decrease.

[0022] In contrast, since the wettability between metal and polymer is relatively good, the wettability can be improved by depositing a metal layer between the ceramic and polymer materials.

[0023] The ceramic assembly of the present invention may include a solid electrolyte of a ceramic material, a polyolefin-based polymer series sealant, a metal support, and a metal layer deposited on a ceramic surface at a bonding interface between the ceramic material solid electrolyte and the polyolefin-based polymer series sealant.

[0024] The above metal layer may be an aluminum metal layer.

[0025] The above ceramic may include NASICON.

[0026] The above polyolefin polymer series sealant may be composed of a three-layer structure of polypropylene (PP), polyethylene (PE), and polypropylene (PP).

[0027] The metal support may serve to prevent breakage of the ceramic during the thermal bonding process. Specifically, the metal support may serve as a guide to prevent breakage of the ceramic when heat and pressure are applied during the thermal bonding process.

[0028] The above metal support may be composed of aluminum.

[0029] The above metal layer may be an aluminum metal layer. Specifically, the metal layer may be deposited on a ceramic surface and bonded to a polypropylene (PP) layer of a polyolefin-based polymer sealant.

[0030] The thickness of the above aluminum metal layer may vary depending on the application.

[0031] FIG. 1 illustrates an overall diagram of a Nasicon assembly according to one embodiment of the present invention.

[0032] Referring to FIG. 1, the Nasicon assembly may include a composition of Nasicon ceramic, an aluminum metal layer, an aluminum support, a sealant film, and a laminate film.

[0033] Nasicon ceramics can play a role in preventing ceramic breakage during the thermal bonding process.

[0034] An aluminum metal layer is deposited on the ceramic surface and can function to improve wettability with the sealant film.

[0035] The aluminum support can serve to prevent ceramic damage during the thermal bonding process.

[0036] The sealant film may be composed of an adhesive polyolefin film.

[0037] Laminate films can function to prevent the penetration of moisture and external gases.

[0038] When forming a metal thin film, a metal with a surface energy similar to or higher than that of the ceramic must be selected. Specifically, the ceramic may be a solid electrolyte. In this case, the metal must not form an alloy with the ions used as mediators in the electrochemical reaction.

[0039] Methods for depositing a metal thin film may include E-beam deposition and sputtering. In addition to the above methods, methods for depositing a metal thin film may include methods that can be employed by a person skilled in the art to deposit a metal thin film between a ceramic solid electrolyte and a polyolefin polymer.

[0040] A method for manufacturing a ceramic assembly according to one embodiment of the present invention may include a step of depositing an aluminum thin film on an edge of a surface of a Nasicon, a step of bonding the Nasicon and a sealant film through thermal bonding, and a step of bonding a laminate film to the sealant film through thermal bonding.

[0041] The above heat bonding can be performed under conditions of 180 to 240°C. Specifically, in the step of bonding the Nasicon and the sealant film through heat bonding, the heat bonding can be performed under conditions of 180 to 240°C.

[0042] In the step of bonding the laminate film to the sealant film through heat fusing, the heat fusing can be performed under conditions of 180 to 240°C.

[0043] FIG. 2 is a process diagram showing a NASICON assembly in which aluminum is deposited according to one embodiment of the present invention.

[0044] Specifically, each step of Fig. 2 can be performed through the following processes, and a description of each step is as follows.

[0045] 1. Step for preparing the Nasicon 2. Step for masking one surface so that aluminum can be deposited on the Nasicon edge using Kapton tape 3. Step for depositing aluminum on the masked surface 4. Step for removing the masking after aluminum deposition 5. Step for fitting an aluminum frame for damage prevention 6. Step for heat-sealing an adhesive sealant film on the surface 7. Step for heat-sealing a sealant film on the opposite surface 8. Step for heat-sealing a laminate film on the sealant film on the aluminum deposition surface

[0046] Figure 4 shows an AFM result graph of the Nasicon surface.

[0047] Referring to Figure 4-1, it can be confirmed that the surface of the Nasicon has an uneven shape, and when comparing before and after deposition of an aluminum metal thin film in Figure 4-2, it can be confirmed that a 500 nm thin film was deposited without any change in the surface shape.

[0048] Figure 5 illustrates an SEM image of the surface after aluminum metal deposition. Referring to Figure 5, it can be confirmed that aluminum has been deposited on the surface of the Nasicon.

[0049] A ceramic assembly according to one embodiment of the present invention can be used in the negative electrode of a seawater secondary battery. Conventional ceramic solid electrolytes and polyolefin-based thermally bonded films can have gaps due to their low wettability.

[0050] Figure 6 illustrates a cross-section of a film manufactured by thermally bonding a Nasicon and a sealant. Referring to Figure 6, it can be confirmed that a gap of approximately 4.1 μm has occurred between the Nasicon and the sealant.

[0051]

[0052] Manufacturing Example 1. NasiCon Assembly Manufacturing Process

[0053] An aluminum (Al) layer is deposited on 3 mm of the 4 mm on both sides of a 10 cm long Nasicon using E-beam deposition. The process of manufacturing a Nasicon assembly by heat-seal-bonding a ceramic solid electrolyte and a sealant is as follows. The ceramic Nasicon is heat-seal-bonded with an adhesive sealant film under conditions of 220°C and 2 MPa.

[0054] Specifically, the NasiCon is fitted into a break-resistant aluminum frame. The sealant film is then aligned to evenly cover both ends of the NasiCon (4 mm), and heat-sealed. This is applied to both sides. The laminate film is then aligned so that the sealant film completely covers it, and heat-sealed. This is applied to only one side.

[0055]

[0056] Manufacturing Example 2. Cathode Manufacturing Process

[0057] 1) Align the NasiCon assembly manufactured in Manufacturing Example 1 above on one side of the cell body and then perform heat bonding. At this time, the part to which the laminate film is attached faces upward.

[0058] 2) Align the insulating sealant film on the attached surface so that it is completely covered by the laminate film, and then proceed with heat bonding.

[0059] 3) After turning the cell body over, attach the SUS mesh, which acts as a current collector, to the terminal of the cell body by spot welding.

[0060] After spot welding, the cathode part is manufactured by repeating the above processes 1) and 2) on the corresponding surface.

[0061] Figure 6 illustrates the appearance of the bonding interface between the Nasicon and the sealant before deposition of the aluminum metal film.

[0062] Referring to Figure 7, it can be seen that the gap that occurred at the interface between the Nasicon and the sealant after the deposition of the aluminum metal film was reduced, thereby reducing the gap at the bonding interface.

[0063]

[0064] Experimental Example 1. Comparison of wettability with polypropylene

[0065] Experiments were conducted to compare the contact angles of pure Nasicon and Nasicon with a thin film of aluminum metal (500 nm) deposited on polypropylene.

[0066] Preheat the Nasikon on a hot plate at 240 degrees for 2 minutes, then place a polypropylene circle with a diameter of 1 mm on the surface and heat for 7 minutes.

[0067] The fabricated sample is used to measure the contact angle between the Nasicon surface and polypropylene using a contact angle meter.

[0068] Figure 8 shows the contact angle between pure Nasicon and polypropylene.

[0069] Figure 9 shows the contact angle between a Nasicon with a thin film of aluminum metal deposited on it and polypropylene.

[0070] Referring to FIGS. 8 and 9, it can be confirmed that the contact angle of the Nasicon after aluminum thin film deposition is lower than that of pure Nasicon. This confirms that the wettability of the Nasicon after aluminum thin film deposition with polypropylene has been improved.

[0071]

[0072] Experimental Example 2. Comparison of moisture permeability

[0073] Experiments were conducted on two cases: Nasicon with aluminum metal film deposited as in the above manufacturing example and pure Nasicon. Nasicon, sealant, and laminate film were heat-sealed to manufacture Nasicon assemblies. Seawater secondary battery anodes were made using the manufactured Nasicon assemblies, and the moisture increase was measured using this. Dimethoxy ethane (DME) was injected into the seawater secondary battery anodes and then immersed in water for a certain period of time. The moisture increase was measured using Karl Fischer coulometry.

[0074] Figure 10 is a graph showing the difference in moisture increase between seawater secondary batteries manufactured using aluminum metal thin film deposited Nasicon and pure Nasicon.

[0075] Referring to Figure 10, it can be confirmed that when a cathode part manufactured using a Nasicon on which an aluminum thin film is deposited is used, the moisture permeability is reduced by 65.8% compared to the existing one.

Claims

1. Solid electrolyte made of ceramic material; Polyolefin polymer series sealant; metal support; A metal layer deposited on a ceramic surface at the bonding interface between the above ceramic material solid electrolyte and the polyolefin polymer series sealant; Ceramic assembly.

2. In paragraph 1, The above metal layer is an aluminum metal layer. Ceramic assembly.

3. A step of depositing an aluminum film on the edge of the Nasicon surface; A step of bonding the above-mentioned NasiCon and sealant film through heat fusion; A step of bonding a laminate film to the sealant film through heat fusion. A method for manufacturing a ceramic assembly comprising:

4. In paragraph 3, The above heat bonding is performed under conditions of 180 to 240°C. Method for manufacturing a ceramic assembly.

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