Electrolyte injection device

Abstract

The present invention relates to an electrolyte injection device comprising: an electrolyte accommodation part which accommodates an electrolyte therein; a socket coupled to the lower end of the electrolyte accommodation part; an injection part which is positioned inside the socket and discharges the electrolyte; a needle pin which opens or closes an injection hole of the injection part; and a main body part which accommodates the electrolyte accommodation part and at least a part of the socket, wherein the injection part comprises two sections having passages of different shapes.

Description

Electrolyte injection device

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0175861 filed November 29, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0002] The present invention relates to an electrolyte injection device. Specifically, it relates to an electrolyte injection device that can shorten the time required for electrolyte injection and prevent the waste of electrolyte during the injection process by changing the shape of the socket for injecting the electrolyte.

[0003]

[0004] Lithium-ion rechargeable batteries, which undergo charging and discharging through the movement of lithium ions, are used not only in small battery cells for mobile devices and small electronic products due to their high energy density and high charging voltage, but also in medium to large battery packs used as energy sources for electric vehicles and power storage systems that require high output and high voltage.

[0005] Lithium secondary batteries are manufactured by housing an electrode assembly in a battery case, injecting an electrolyte, and sealing it; injecting a sufficient amount of electrolyte to ensure the electrode assembly is evenly impregnated with the electrolyte is an important requirement for preventing performance degradation of the battery cell.

[0006] Recently, there has been an increasing need for battery cells with high energy density for use in medium to large battery packs. Increasing the size of the battery cell is emerging as a good alternative for increasing energy density. However, as the size of the battery cell increases, the time required to inject the electrolyte also increases, thereby extending the time required for battery cell manufacturing.

[0007] Accordingly, various attempts are being made to reduce the time required for battery cell manufacturing by increasing the electrolyte injection speed and shortening the electrolyte injection time.

[0008] Meanwhile, the appropriate amount of electrolyte to be injected into the battery case is determined by considering the volume of the electrode assembly before injection, but during the process of injecting the electrolyte into the battery case, a vortex is generated, causing some of the electrolyte to be unable to be inserted into the battery case and contaminating the electrolyte injection device.

[0009] In addition, when stopping the electrolyte injection in the electrolyte injection device, the electrolyte may splash and contaminate the electrolyte injection device, and the electrolyte may also scatter and contaminate the electrolyte injection device during the process of injecting the electrolyte.

[0010] As a result, since the preset amount of electrolyte cannot be injected into the battery case, the actual amount of electrolyte injected into the battery case is less than the preset amount.

[0011] Consequently, a method is being used to inject a few milliliters more of electrolyte than the preset amount. As a result, the correct amount of electrolyte cannot be injected, and the electrolyte may be wasted unnecessarily.

[0012] In this regard, FIG. 1 is a vertical cross-sectional view and a partially enlarged cross-sectional view of a conventional electrolyte injection device.

[0013] Referring to FIG. 1, a conventional electrolyte injection device is configured such that a plurality of units are provided inside a main body (400), with the configuration comprising an electrolyte receiving part (100) that contains an electrolyte inside, an injection part (200) located below the electrolyte receiving part, and a needle pin (300) that opens and closes the injection port (201) of the injection part (200) as a single unit.

[0014] The injection part (200) is configured to form an internal space of the socket (500), and is configured in the shape of a first truncated cone with a diameter that narrows as it goes from top to bottom, a cylinder with a constant diameter at the bottom, and a second truncated cone with a diameter that narrows as it goes further down. The angle of the inclined surface of the first truncated cone is 28°, and the angle of the inclined surface of the second truncated cone is 69°. In addition, the diameter of the cylinder is 5.6 mm, and the diameter of the injection part (201) is 2.5 mm. The injection port (201) is located on the same plane as the lower surface (410) of the main body.

[0015] When injecting electrolyte into cylindrical battery cells using an electrolyte injection device of this type, the degree of contamination of the device is severe, so it is necessary to reduce the amount of wasted electrolyte.

[0016] Meanwhile, to shorten the time for injecting the electrolyte, methods such as widening the size of the electrolyte injection port or increasing the amount of electrolyte injected per unit time can be considered; however, if the amount and speed of the electrolyte injection are too high, the separator constituting the electrode assembly may fold, causing an internal short circuit between the anode and the cathode.

[0017] Therefore, there is a need for technology that can improve the level of contamination of the electrolyte injection device by reducing the vortex phenomenon during the electrolyte injection process and lowering the splashing of the electrolyte.

[0018]

[0019] The present invention aims to solve the above-mentioned problems by providing an electrolyte injection device that can improve the contamination level of the electrolyte injection device and shorten the electrolyte injection time by minimizing the scattering of the electrolyte during the electrolyte injection process.

[0020]

[0021] An electrolyte injection device according to the present invention for achieving such an objective comprises an electrolyte receiving portion that receives an electrolyte, a socket coupled to the lower end of the electrolyte receiving portion, an injection portion located inside the socket that discharges the electrolyte, a needle pin that opens and closes the injection port of the injection portion, and a main body portion that receives at least a part of the electrolyte receiving portion and the socket, wherein the injection portion may be composed of two zones having different passage shapes.

[0022] In the electrolyte injection device according to the present invention, the socket may include an inner socket located within the main body and an outer socket extending downward from the main body.

[0023] In the electrolyte injection device according to the present invention, the injection part may be composed of a first zone located at the top and formed in a cylindrical shape, and a second zone located at the bottom and formed in a truncated cone shape with a diameter that narrows at a constant slope from the first zone to the injection port.

[0024] In the electrolyte injection device according to the present invention, the diameter (R2) of the injection port may be configured to be 30% to 40% of the diameter (R1) of the first zone.

[0025] In the electrolyte injection device according to the present invention, the diameter of the injection port may be 4.71 mm, and the diameter of the first zone may be 13 mm.

[0026] In the electrolyte injection device according to the present invention, the height (H2) of the external socket may be 35% or more to 50% or less of the total height (H3) of the socket.

[0027] In the electrolyte injection device according to the present invention, the height (H2) of the outer socket may be configured to be 60% to 80% of the height (H1) of the inner socket.

[0028] In the electrolyte injection device according to the present invention, the height of the outer socket may be 25 mm, and the height of the inner socket may be 16.4 mm.

[0029] An electrolyte injection device according to the present invention includes a hopper coupled to the external socket, and the external socket can be coupled to be inserted into the hopper.

[0030] In the electrolyte injection device according to the present invention, the lower part of the second zone of the injection port may be formed inside the outer socket.

[0031] In the electrolyte injection device according to the present invention, the hopper is coupled to the socket at the upper end and coupled to the cylindrical battery cell at the lower end, and may have a first sealing member at the upper end and a second sealing member at the lower end.

[0032]

[0033] The present invention can also be provided in a form that combines various means for solving the above problem.

[0034]

[0035] The present invention significantly reduces vortices when discharging electrolyte, thereby minimizing contamination of the electrolyte injection device due to vortices.

[0036] In addition, the electrolyte injection time was shortened by securing the flow rate through a modified shape of the injection port that discharges the electrolyte.

[0037]

[0038] Figure 1 is a vertical cross-sectional view and a partial enlarged cross-sectional view of a conventional electrolyte injection device.

[0039] FIG. 2 is a vertical cross-sectional view and a partially enlarged cross-sectional view of an electrolyte injection device according to the present invention.

[0040] FIG. 3 is a vertical cross-sectional view comparing the socket portion of the electrolyte injection device according to FIG. 1 and FIG. 2.

[0041] Figure 4 is a vertical cross-sectional view showing the state in which the electrolyte injection device according to Figure 2 is connected to a cylindrical battery cell through a hopper.

[0042] Figure 5 is a photograph of the results of the example and comparative example.

[0043]

[0044] Embodiments that enable a person skilled in the art to easily practice the present invention are described in detail below with reference to the attached drawings. In describing the operating principles of the embodiments of the present invention in detail, specific descriptions of related known functions or configurations are omitted if it is determined that such detailed descriptions may unnecessarily obscure the essence of the present invention.

[0045] The same reference numerals are used for parts having similar functions and operations throughout the drawings. Throughout the specification, when a part is described as being connected to another part, this includes not only cases where they are directly connected but also cases where they are indirectly connected with other elements in between. Furthermore, the inclusion of a certain component means that, unless specifically stated otherwise, it does not exclude other components but rather implies that additional components may be included.

[0046] Descriptions that specify components by limiting or adding them may be applied to all inventions unless specifically limited, and are not limited to descriptions of specific inventions.

[0047] Throughout the description of the invention and claims of this application, anything indicated in the singular includes cases where it is plural unless otherwise noted.

[0048] Throughout the description of the invention and the claims of the present invention, "or" includes "and" unless otherwise noted. Therefore, "comprising A or B" means all three of the above cases: including A, including B, or including both A and B.

[0049] The present invention is described in detail with reference to the drawings and embodiments.

[0050] The electrolyte injection device according to the present invention may be configured such that a unit injection device comprising an electrolyte receiving portion (100), an injection portion (200), and a needle pin (300) is disposed in a space formed inside a main body portion (400), and may have two or more unit injection devices. Additionally, the unit injection devices may be configured such that they form two or more rows and two or more columns and are arranged at regular intervals.

[0051] FIG. 2 is a vertical cross-sectional view and a partially enlarged cross-sectional view of an electrolyte injection device according to the present invention. The vertical cross-sectional view of FIG. 2 shows three unit injection devices arranged.

[0052] FIG. 2 is a vertical cross-sectional view and a partially enlarged cross-sectional view of an electrolyte injection device according to the present invention.

[0053] Referring to FIG. 2, the electrolyte injection device according to the present invention comprises an electrolyte receiving portion (100) that receives an electrolyte inside, a socket (500) coupled to the bottom of the electrolyte receiving portion (100), an injection portion (200) located inside the socket (500) and discharging an electrolyte, a needle pin (300) that opens and closes an injection port (201) of the injection portion (200), and a main body portion (400) that receives at least a portion of the electrolyte receiving portion (100) and the socket (500), and the injection portion (200) is composed of two zones with different passage shapes.

[0054] The electrolyte contained in the electrolyte receiving section (100) is discharged through the injection section (200) to the injection port (201). When the needle pin (300) positioned above the injection port (201) moves downward to block the injection port (201), the injection port (201) is closed, and conversely, when the needle pin (300) moves upward, the injection port (201) is opened. A sealing member, such as rubber or an O-ring, is added to the bottom of the needle pin (300), so that when the needle pin (300) blocks the injection port (201), the injection port (201) can be completely sealed.

[0055] In the present invention, the socket (500) includes a portion extending downward from the lower surface (410) of the main body. Specifically, the socket (500) includes an inner socket (510) located within the main body (400) and an outer socket (520) extending downward from the main body (400).

[0056] A path is formed inside the socket (500) through which the electrolyte can move, and an injection part (200) is formed by said path.

[0057] The shape of the passage of the injection part (200) may be a cylindrical shape with a constant diameter, or a truncated cone shape with a diameter that narrows toward the bottom.

[0058] Specifically, the injection section (200) is composed of a first section (210) located at the top and formed in a cylindrical shape, and a second section (220) located at the bottom and formed in a truncated cone shape with a diameter that narrows at a constant slope from the first section (210) to the injection port (201).

[0059] The present invention is formed such that the injection part (200) includes a first zone and a second zone made of two different forms.

[0060] If the shape of the injection section (200) is configured in various ways, turbulent flow is formed and injected as the section of the electrolyte flow rate change increases; conversely, if the shape of the injection section (200) changes little, the section of the electrolyte flow rate change is small, so the possibility of injection in a laminar flow state increases. If turbulence is formed in the electrolyte, the possibility of scattering may increase. The present invention minimizes deformation of the path through which the electrolyte passes by configuring the injection section (200) to include only the first and second zones. Therefore, the present invention can reduce the level of scattering when the electrolyte is discharged.

[0061] The diameter of the injection port (R2) is configured to be 30% to 40% of the diameter (R1) of the first zone, for example, the diameter (R2) of the injection port may be 4.71 mm and the diameter (R1) of the first zone may be 13 mm.

[0062] Meanwhile, the electrolyte injection device according to the present invention is configured such that the height (H1) of the inner socket (510) accommodated inside the main body (400) is extended compared to the conventional electrolyte injection device shown in FIG. 1. For example, when the diameter (R2) of the injection port is 4.71 mm and the diameter (R1) of the first zone is 13 mm, the height (H1) of the inner socket can be configured to be 25 mm.

[0063] Figure 4 is a vertical cross-sectional view showing the state in which the electrolyte injection device according to Figure 2 is connected to a cylindrical battery cell through a hopper.

[0064] Referring to FIG. 4, the electrolyte injection device according to the present invention includes a hopper (600) coupled to an external socket (520), and the external socket (520) is coupled so as to be inserted into the hopper (600).

[0065] The lower part (222) of the second zone of the injection port (200) is formed inside the external socket (520). That is, the upper part (221) of the first zone of the injection port (200) forms a portion embedded inside the main body (400), and the lower part (222) of the second zone is configured to extend outward from the lower surface (410) of the main body.

[0066] The hopper (600) is coupled to the socket (500) at the upper end and to the cylindrical battery cell (10) at the lower end, and is provided with a first sealing member (610) at the upper end and a second sealing member (620) at the lower end.

[0067] That is, the socket (500) and the cylindrical battery cell (10) can be connected via the hopper (600). Additionally, the sealing force is increased at the part where the socket (500) and the hopper (600) are connected by the first sealing member (610), and the sealing force is increased at the part where the hopper (600) and the cylindrical battery cell (10) are connected by the second sealing member (620).

[0068] The electrolyte discharged through the injection port (201) at the end of the injection section (200) passes through the inside of the hopper (600) and is injected into the cylindrical battery cell (10). Since the state of being sealed by the first sealing member (610) and the second sealing member (620) is maintained, leakage of the electrolyte outside the hopper (600) can be prevented.

[0069] However, the electrolyte may scatter inside the hopper (600), but in the present invention, the level of contamination caused by scattering is reduced by modifying the shape of the socket (500).

[0070] The first sealing member (610) and the second sealing member (620) may be O-rings, and the O-rings may be made of Ethylene-Propylene Diene Monomer (EPDM) material.

[0071] Referring to FIG. 3 in conjunction with FIG. 4, the height (H2) of the outer socket inserted into the hopper (600) is 35% or more to 50% or less of the total height (H3) of the socket. Additionally, the height (H2) of the outer socket is configured to be 60% to 80% of the height (H1) of the inner socket. For example, the height (H2) of the outer socket may be 25 mm and the height (H1) of the inner socket may be 16.4 mm.

[0072]

[0073] The following description refers to embodiments of the present invention, but this is for the sake of easier understanding of the present invention and does not limit the scope of the present invention.

[0074]

[0075] <Example>

[0076] After attaching a hopper to the top of a cylindrical battery cell, it is inserted into a chamber, and while under vacuum pressure, the top of the hopper is connected to the socket of the electrolyte injection device shown in FIG. 2.

[0077] With the inside of the battery cell maintained in a vacuum state, the pressure inside the chamber is raised to atmospheric pressure to create a pressure difference, and 35 ml of electrolyte is injected using the pressure difference by raising the needle pin. At this time, the time taken to inject 35 ml of electrolyte was measured to be 2.32 seconds.

[0078] The electrolyte injection device is structured such that the outer socket protrudes further downward from the lower surface of the main body, the first zone is cylindrical with a diameter of 13 mm and a height of 25 mm, the second zone has a constant angle of inclination of the truncated cone surface and a diameter that narrows uniformly, and the diameter of the injection port is 4.71 mm. In addition, the height of the lower part of the second zone forming the internal space of the outer socket is 16.4 mm.

[0079]

[0080] <Comparative Example>

[0081] After attaching a hopper to the top of a cylindrical battery cell, it is inserted into a vacuum chamber, and while under vacuum pressure, the top of the hopper is connected to the socket of a conventional electrolyte injection device shown in FIG. 1.

[0082] With the inside of the battery cell maintained in a vacuum state, the pressure inside the chamber is raised to atmospheric pressure to create a pressure difference, and 35 ml of electrolyte is injected using the pressure difference by raising the needle pin. At this time, the time taken to inject 35 ml of electrolyte was measured to be 2.85 seconds.

[0083] In the electrolyte injection device of Fig. 1, the injection section is configured as a first truncated cone, a cylinder with a constant diameter at its lower end, and a second truncated cone with a diameter that becomes narrower as it goes down. The angle of the inclined surface of the first truncated cone is 28°, and the angle of the inclined surface of the second truncated cone is 69°. Additionally, the diameter of the cylinder is 5.6 mm, and the diameter of the injection section is 2.5 mm.

[0084] Figure 5 is a photograph of the results of the example and comparative example.

[0085] Referring to FIG. 5, (a) is the result of an example and (b) is the result of a comparative example.

[0086] As a result of checking the degree of external contamination of the hopper, (a) can be seen that electrolyte forms small droplets on the outer surface of the hopper, as the level of splashing decreases as the number of zones constituting the injection part decreases. (b) can be seen that large droplets of electrolyte form on the outer surface of the hopper and furthermore, electrolyte flows down, as the level of electrolyte splashing is high.

[0087]

[0088] In this way, when using the electrolyte injection device according to the present invention, the electrolyte injection time can be significantly shortened by providing the first zone of the injection part as a large-diameter cylinder and expanding the diameter of the injection port.

[0089] In addition, by minimizing the number of zones constituting the injection section, the level of electrolyte splashing is lowered, resulting in the degree of contamination of the hopper being minimized.

[0090]

[0091] A person skilled in the art to which the present invention pertains would be able to perform various applications and modifications within the scope of the present invention based on the above content.

[0092]

[0093] (Explanation of symbols)

[0094] 10: Cylindrical battery cell

[0095] 100: Electrolyte receiving portion

[0096] 200: Injection part

[0097] 201: Injection duct

[0098] 210: Zone 1

[0099] 220: Zone 2

[0100] 221: Upper part of Zone 2

[0101] 222: Lower part of Zone 2

[0102] 300: Needlepin

[0103] 400: Main body

[0104] 410: Bottom of the main body

[0105] 500: Socket

[0106] 510: Internal socket

[0107] 520: External socket

[0108] 600: Hopper

[0109] 610: First sealing member

[0110] 620: Second sealing member

[0111] H1: Height of the internal socket

[0112] H2: Height of the external socket

[0113] H3: Total socket height

[0114] R1: Diameter of Zone 1

[0115] R2: Diameter of the injection port

[0116]

[0117]

[0118]

Claims

1. An electrolyte receiving portion that accommodates an electrolyte inside; A socket coupled to the lower end of the above electrolyte receiving portion; An injection part located inside the above socket and discharging electrolyte; A needle pin for opening and closing the injection port of the injection part; and A main body portion accommodating at least a portion of the above electrolyte receiving portion and the above socket; Includes, The above injection section is an electrolyte injection device composed of two zones with different passage shapes.

2. In Paragraph 1, The above socket is an electrolyte injection device comprising an inner socket located within the main body and an outer socket extending downward from the main body.

3. In Paragraph 1, The above injection part is, An electrolyte injection device comprising a first zone located at the top and formed in a cylindrical shape, and a second zone located at the bottom and formed in a truncated cone shape with a diameter that narrows at a constant slope from the first zone to the injection port.

4. In Paragraph 3, An electrolyte injection device in which the diameter of the injection port (R2) is configured to be 30% to 40% of the diameter (R1) of the first zone.

5. In Paragraph 4, An electrolyte injection device having a diameter of 4.71 mm for the injection port and a diameter of 13 mm for the first zone.

6. In Paragraph 2, An electrolyte injection device in which the height (H2) of the above external socket is 35% or more to 50% or less of the total height (H3) of the socket.

7. In Paragraph 2, An electrolyte injection device in which the height (H2) of the outer socket is 60% to 80% of the height (H1) of the inner socket.

8. In Paragraph 7, An electrolyte injection device having an external socket height of 25 mm and an internal socket height of 16.4 mm.

9. In Paragraph 2, It includes a hopper coupled to the above external socket, The above external socket is an electrolyte injection device that is coupled to be inserted into the hopper.

10. In Paragraph 9, Electrolyte injection device in which the lower part of the second zone of the injection port is formed inside the above external socket.

11. In Paragraph 9, The above hopper is coupled to the socket at the upper end and to the cylindrical battery cell at the lower end, and An electrolyte injection device having a first sealing member at the upper end and a second sealing member at the lower end.

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