Electrolyte injection device

Abstract

The present invention relates to an electrolyte injection device comprising: an electrolyte accommodation part for accommodating an electrolyte therein; a socket coupled to a lower end portion of the electrolyte accommodation part; an injection port located inside the socket to discharge the electrolyte; a needle pin for opening and closing the injection port of an injection part; and a main body for accommodating the electrolyte accommodation part and at least a portion of the socket, wherein the socket has a plurality of air holes formed therein.

Description

Electrolyte injection device

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0175841 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 for receiving an electrolyte inside, a socket coupled to the lower end of the electrolyte receiving portion, an injection portion located inside the socket for discharging an electrolyte, a needle pin for opening and closing an injection port of the injection portion, and a main body portion for receiving at least a part of the electrolyte receiving portion and the socket, wherein the socket may have a plurality of air holes formed therein.

[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 as a cylinder with a relatively large diameter, a third zone located at the bottom and formed as a cylinder with a relatively small diameter, and a second zone connecting the first zone and the third zone, wherein the diameter narrows as it goes from the first zone to the third zone.

[0024] In the electrolyte injection device according to the present invention, the diameter of the third zone may be configured to be 50% or more of the diameter of the first zone.

[0025] In the electrolyte injection device according to the present invention, the diameter of the third zone may be 5.6 mm, and the diameter of the first zone may be 10 mm.

[0026] In the electrolyte injection device according to the present invention, a plurality of air holes communicating with the outside may be formed in the third zone.

[0027] In the electrolyte injection device according to the present invention, the air hole penetrates the outer socket from the side of the third zone and extends downward diagonally to lead to the lower surface of the outer socket where the injection port is located.

[0028] In the electrolyte injection device according to the present invention, the diameter of the air hole may be 1 mm.

[0029] In the electrolyte injection device according to the present invention, the height of the first zone may be configured to be at least three times the diameter of the first zone.

[0030] 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.

[0031] In the electrolyte injection device according to the present invention, a lower first zone, a second zone, and a third zone among the injection ports may be formed inside the external socket.

[0032] 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.

[0033] In the electrolyte injection device according to the present invention, the sum of the heights of the lower part of the first zone, the second zone, and the third zone constituting the interior of the external socket inserted into the hopper may be 50% or more of the total height of the injection part.

[0034] In the electrolyte injection device according to the present invention, the sum of the heights of the lower part of the first zone, the second zone, and the third zone may be 30 mm.

[0035]

[0036] The present invention can also be provided in a form that combines various means for solving the above problem.

[0037]

[0038] The present invention significantly reduces vortices when discharging electrolyte, thereby minimizing contamination of the electrolyte injection device due to vortices.

[0039] 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.

[0040]

[0041] Figure 1 is a vertical cross-sectional view and a partial enlarged cross-sectional view of a conventional electrolyte injection device.

[0042] 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.

[0043] FIG. 3 is a vertical cross-sectional view comparing the socket portion of the electrolyte injection device according to FIG. 1 and FIG. 2.

[0044] 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.

[0045] Figure 5 is a photograph of the results of the example and comparative example.

[0046]

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] The present invention is described in detail with reference to the drawings and embodiments.

[0053] 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.

[0054] 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.

[0055]

[0056] 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 socket (500) has a plurality of air holes (231) formed therein.

[0057] 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.

[0058] A path is formed inside the socket (500) through which the electrolyte can move, and an injection part (200) is formed by said path.

[0059] 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).

[0060] FIG. 3 is a vertical cross-sectional view comparing the socket portion of the electrolyte injection device according to FIG. 1 and FIG. 2.

[0061] Referring to FIG. 3, (a) illustrates a socket (500) and injection part (200) of a conventional electrolyte injection device, and (b) illustrates a socket (500) and injection part (200) of an electrolyte injection device according to the present invention.

[0062] (a) differs in that the end of the injection port (201) is located on the same plane as the lower surface of the main body (410), whereas (b) is in a shape where the end of the injection port (201) is further extended from the lower surface of the main body (410). That is, the present invention provides the effect of reducing the degree of contamination of the socket (500) by the electrolyte during the process of injecting the electrolyte by configuring the socket (500) to extend further downward than the lower surface of the main body (410).

[0063] The injection section (200) is composed of a first section (210) located at the top and formed as a cylinder with a relatively large diameter, a third section (230) located at the bottom and formed as a cylinder with a relatively small diameter, and a second section (220) connecting the first section (210) and the third section (230) and formed in a shape where the diameter narrows as it goes from the first section (210) to the third section (230).

[0064] Specifically, the diameter (R2) of the third zone is composed of 50% or more of the diameter (R1) of the first zone, and more specifically, is composed of 50% or more to 70% or less of the diameter (R1) of the first zone. For example, the diameter (R2) of the third zone is 5.6 mm, and the diameter (R1) of the first zone is 10 mm.

[0065] Meanwhile, a plurality of air holes (231) communicating with the outside are formed in the third zone (230), and as a result of the effect of reducing vortex flow when the electrolyte is injected through the air holes (231), the scattered electrolyte can be reduced.

[0066] The number of air holes (231) is not specifically limited, but is formed within the range of 2 to 5, and the spacing between all air holes (231) can be uniformly configured.

[0067] The air hole (231) is configured to penetrate the outer socket (520) from the side of the third zone (230) and extend downward diagonally to lead to the lower surface of the outer socket where the end of the injection port (201) is located. The air hole (231) is formed as a cylindrical shape with a constant diameter, and the diameter (R3) of the air hole may be 1 mm to 3 mm, and specifically 1 mm.

[0068] Meanwhile, the electrolyte injection device according to the present invention is configured such that the height (H1) of the first zone accommodated inside the main body (400) is extended when compared to the conventional electrolyte injection device shown in FIG. 1. Specifically, the height (H1) of the first zone can be configured to be at least three times the diameter (R1) of the first zone. For example, when the diameter (R1) of the first zone is 10 mm, the height (H1) of the first zone can be 32 mm.

[0069] In the present invention, the second section (220) is configured in the shape of a truncated cone, and the angle (r) formed by the side of the truncated cone may be 69°.

[0070] 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.

[0071] 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).

[0072] The first zone lower part (212), the second zone (220), and the third zone (230) of the injection port (200) are formed inside the external socket (520). That is, the first zone lower part (212), the second zone (220), and the third zone (230) are configured to extend outward from the lower surface (410) of the main body.

[0073] 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.

[0074] 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).

[0075] 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.

[0076] 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).

[0077] 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.

[0078] Referring to FIG. 3 along with FIG. 4, the sum of the heights (H2) of the first lower section (212), the second section (220), and the third section (230) constituting the interior of the external socket (520) inserted into the hopper (600) is 50% or more of the total height (H3) of the injection section, specifically, 50% or more to 80% or less.

[0079] For example, the sum of the heights (H2) of the lower part of the first zone (212), the second zone (220), and the third zone (230) may be 30 mm.

[0080]

[0081] 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.

[0082]

[0083] <Example>

[0084] 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.

[0085] 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 1.57 seconds.

[0086] The electrolyte injection device is structured such that the external socket protrudes further downward from the lower surface of the main body, and the first zone is cylindrical with a diameter of 10 mm and a height of 32 mm, the second zone has a truncated cone slope angle of 69°, and the third zone has a diameter of 5.6 mm and has two air holes formed therein. In addition, the sum of the heights of the lower part of the first zone, the second zone, and the third zone forming the internal space of the external socket is 30 mm.

[0087]

[0088] <Comparative Example>

[0089] 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.

[0090] 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.

[0091] In the electrolyte injection device of Fig. 1, the injection part 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 in the first truncated cone is 28°, and the angle of the inclined surface in the second truncated cone is 69°. Additionally, the diameter of the cylinder is 5.6 mm, and the diameter of the injection port is 2.5 mm.

[0092] Figure 5 is a photograph of the results of the example and comparative example.

[0093] Referring to FIG. 5, (a) is the result of an example and (b) is the result of a comparative example.

[0094] As a result of checking the degree of external contamination of the hopper, it can be seen that (a) is mainly contaminated only at the bottom part of the hopper due to reduced vortex levels, and (b) is contaminated up to the top end of the hopper due to a large amount of scattered electrolyte because of high vortex levels.

[0095]

[0096] 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.

[0097] In addition, by providing an air hole in the third zone, the scattering of the electrolyte can be reduced, thereby reducing the contamination range of the hopper.

[0098]

[0099] 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.

[0100]

[0101] (Explanation of symbols)

[0102] 10: Cylindrical battery cell

[0103] 100: Electrolyte receiving portion

[0104] 200: Injection part

[0105] 201: Injection duct

[0106] 210: Zone 1

[0107] 211: Upper part of Zone 1

[0108] 212: Lower part of Zone 1

[0109] 220: Zone 2

[0110] 230: Zone 3

[0111] 231: Airhole

[0112] 300: Needlepin

[0113] 400: Main body

[0114] 410: Bottom of the main body

[0115] 500: Socket

[0116] 510: Internal socket

[0117] 520: External socket

[0118] 600: Hopper

[0119] 610: First sealing member

[0120] 620: Second sealing member

[0121] H1: Height of Zone 1

[0122] H2: Sum of the heights of the lower part of Zone 1, Zone 2, and Zone 3

[0123] H3: Total height of the injection section

[0124] R1: Diameter of Zone 1

[0125] R2: Diameter of Zone 3

[0126] R3: Diameter of the air hole

[0127]

[0128]

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 socket is an electrolyte injection device having a plurality of air holes formed therein.

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, A first zone located at the top and formed of a cylinder with a relatively large diameter; A third zone located at the bottom and formed of a cylinder with a relatively small diameter; and An electrolyte injection device comprising: a second zone connecting the first zone and the third zone, wherein the diameter narrows as it goes from the first zone to the third zone.

4. In Paragraph 3, An electrolyte injection device in which the diameter (R2) of the third zone is 50% or more of the diameter (R1) of the first zone.

5. In Paragraph 4, An electrolyte injection device having a diameter of 5.6 mm for the third zone and a diameter of 10 mm for the first zone.

6. In Paragraph 3, Electrolyte injection device having a plurality of air holes formed in the third zone above that communicate with the outside.

7. In Paragraph 6, The above air hole penetrates the outer socket from the side of the third zone and extends downward diagonally to lead to the lower surface of the outer socket having the injection port, forming an electrolyte injection device.

8. In Paragraph 7, Electrolyte injection device having an air hole diameter (R3) of 1 mm.

9. In Paragraph 3, An electrolyte injection device in which the height (H1) of the first zone is configured to be at least three times the diameter (R1) of the first zone.

10. 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.

11. In Paragraph 10, An electrolyte injection device in which the lower part of the first zone, the second zone, and the third zone of the injection port are formed inside the above-mentioned external socket.

12. In Paragraph 10, 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.

13. In Paragraph 10, An electrolyte injection device in which the sum of the heights (H2) of the lower first zone, the second zone, and the third zone constituting the interior of the external socket inserted into the hopper is 50% or more of the total height (H3) of the injection section.

14. In Paragraph 13, Electrolyte injection device in which the sum of the heights (H2) of the lower part of the first zone, the second zone, and the third zone is 30 mm.

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