Negative pressure cup and battery cell

Abstract

The utility model relates to the field of battery cell production, and discloses a negative pressure cup and a battery cell, the negative pressure cup comprises a cup body, a refrigeration part, a first connecting pipe and a second connecting pipe, the cup body is provided with an inlet and an outlet, the refrigeration part is fixedly installed on the cup body, the refrigeration part is used for cooling the interior of the cup body, the first connecting pipe is installed at the inlet, and the second connecting pipe is installed at the outlet. The refrigeration part is installed on the cup body, the refrigeration part cools the interior of the cup body, when the electrolyte gasified in the battery cell enters the cup body through the first connecting pipe, due to the fact that the temperature in the cup body is low, the electrolyte in the gasified state is liquefied and flows back into the battery cell again, and the loss of the electrolyte is reduced.

Description

Technical Field

[0001] The present application relates to the field of battery cell production, and in particular to a negative pressure cup and a battery cell. Background Art

[0002] During the charging, discharging, and formation processes of lithium-ion batteries, negative pressure cups serve as a key auxiliary device, effectively removing excess gas and electrolyte bubbles generated within the battery cell during charging. Especially during the high-temperature formation stage, some electrolyte vaporizes due to the rising temperature, forming a gaseous electrolyte. This gas, along with the bubbles, is discharged through the battery cell's injection port.

[0003] The working principle of a traditional negative pressure cup is to connect to the battery cell filling port and use the negative pressure effect to create a vacuum environment inside the battery cell, thereby extracting excess gas and electrolyte bubbles from the battery cell. These bubbles condense into electrolyte and are stored in the negative pressure cup. After the negative pressure formation is completed, the vacuum is broken and a slight positive pressure technology is used to return the electrolyte stored in the negative pressure cup to the battery cell, ensuring the stability of the battery cell filling volume.

[0004] However, existing negative pressure cup designs have a significant flaw: a lack of condensation. During the high-temperature (e.g., 50°C) formation process, vaporized electrolyte (i.e., gaseous electrolyte) is drawn out by negative pressure along with the bubbles generated by the chemical reaction. Because the negative pressure cup lacks a condensation mechanism, this gaseous electrolyte cannot effectively condense back into a liquid state within the cup. This results in inconsistent electrolyte injection levels before and after formation, impacting the performance and safety of the battery cell. Utility Model Content

[0005] In view of this, the purpose of this application is to overcome the deficiencies in the prior art and provide a negative pressure cup and a battery cell.

[0006] To achieve the above objectives, the technical solutions adopted in this application are as follows:

[0007] This application provides:

[0008] A negative pressure cup, comprising:

[0009] a cup body having an inlet and an outlet;

[0010] A refrigeration component, which is fixedly mounted on the cup body and is used to cool the interior of the cup body;

[0011] a first connecting pipe, the first connecting pipe being installed at the inlet;

[0012] A second connecting pipe is installed at the outlet.

[0013] Furthermore, the cup body includes a cup shell, and the interior of the cup shell defines a accommodating cavity, the inlet is a first mounting hole opened on the cup shell, and the outlet is a second mounting hole opened on the cup shell, the first mounting hole is used for the first connecting tube to be installed and communicated with the accommodating cavity, and the second mounting hole is used for the first connecting tube to be installed and communicated with the accommodating cavity.

[0014] Furthermore, the accommodating cavity includes a first cavity and a second cavity, the first mounting hole is connected to the second cavity, and the cross-section of the second cavity gradually increases from the first mounting hole toward the first cavity.

[0015] Furthermore, the second cavity is conical.

[0016] Furthermore, a heat sink is installed on the cup body, and the heat sink is used to dissipate heat from the refrigeration component. The heat sink includes a connecting plate fixedly installed on the cup body, the connecting plate is in contact with the refrigeration component, and a heat sink is provided on the connecting plate.

[0017] Furthermore, the cup body is installed with a fixing piece, which is used to fix the cup body. The fixing piece includes a fixing plate, and the fixing plate is provided with N connection holes, satisfying: N≥1.

[0018] Furthermore, the refrigeration element is a ceramic condenser or a semiconductor refrigeration plate.

[0019] Furthermore, the cross section of the cup body is circular, elliptical or polygonal.

[0020] Furthermore, the cup body is provided with a scale.

[0021] The present application also discloses a battery cell having a liquid injection port, wherein the liquid injection port is connected to the negative pressure cup described in any one of the above directions.

[0022] In this application, a refrigeration component is installed on the cup body to cool the inside of the cup body. When the vaporized electrolyte in the battery cell enters the cup body through the first connecting tube, the vaporized electrolyte will liquefy due to the low temperature in the cup body, and then flow back into the battery cell, reducing the loss of electrolyte.

[0023] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 Shows a schematic diagram of the overall structure of the negative pressure cup of this application;

[0026] Figure 2 Shows a schematic cross-sectional view of the negative pressure cup of the present application;

[0027] Figure 3 A schematic top view of the negative pressure cup of the present application is shown.

[0028] Description of main component symbols:

[0029] 100-cup body; 110-cup shell; 120-accommodating cavity; 121-first cavity; 122-second cavity; 130-first mounting hole; 140-second mounting hole; 200-refrigeration component; 300-first connecting pipe; 400-second connecting pipe; 500-heat dissipation component; 510-connecting plate; 520-heat sink; 600-fixing component; 610-fixing plate; 620-connecting hole. DETAILED DESCRIPTION

[0030] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0031] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0033] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0034] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0035] The negative pressure cup is an auxiliary device used in the formation equipment in the discharge process of battery cells (lithium batteries). During the charging process of the battery cells, excess gas and electrolyte enamel will be generated inside the battery cells. During the high-temperature formation process, the electrolyte will be vaporized, and these gases and electrolyte bubbles will be discharged through the injection port of the battery cells. Generally, the excess gas and electrolyte bubbles inside the battery cells are discharged through the negative pressure cup. The inlet of the negative pressure cup is connected to the injection port of the battery cells, and the negative pressure cup is vacuumed. When negative pressure enters the battery cells, a vacuum will be formed inside the battery cells, and the excess gas and electrolyte in the battery cells will be extracted. The electrolyte bubbles form electrolyte in the negative pressure cup and are stored in the negative pressure cup. After the negative pressure formation is completed, under the action of breaking the vacuum and slightly positive pressure, the electrode liquid stored in the negative pressure cup is pumped back into the battery cells again, thereby playing the role of electrolyte reflux, so that the battery cell injection volume remains the same as before.

[0036] However, the existing negative pressure cup has some disadvantages. For example, during the high-temperature (50°C) formation process of the liquid electrolyte, part of the electrolyte is vaporized to form a gaseous electrolyte. During the negative pressure pumping process, the electrolyte will be pumped away along with the bubbles generated by the chemical reaction. The gaseous electrolyte cannot form a liquid electrolyte in the negative pressure cup and flow back into the battery cell, resulting in the loss of battery cell injection volume before and after the battery cell is formed.

[0037] To this end, the present application provides a negative pressure cup, which includes a cup body 100, a refrigeration component 200, a first connecting tube 300 and a second connecting tube 400, wherein the cup body 100 has an inlet and an outlet, the refrigeration component 200 is fixedly installed on the cup body 100, and the refrigeration component 200 is used to cool the inside of the cup body 100, the first connecting tube 300 is installed at the inlet, and the second connecting tube 400 is installed at the outlet.

[0038] In this embodiment, the first connecting tube 300 and the second connecting tube 400 are both connected to the interior of the cup body 100. Specifically, the first connecting tube 300 is sealed and connected to the liquid injection port of the battery cell, and the second connecting tube 400 is connected to the corresponding negative pressure device. The negative pressure device vacuums the interior of the cup body 100 through the second connecting tube 400. The passage formed by the second connecting tube 400, the cup body 100, the first connecting tube 300 and the liquid injection port of the battery cell realizes vacuuming the interior of the battery cell, thereby preparing for the battery cell formation process.

[0039] Exemplarily, the negative pressure device mentioned above is a vacuum pump, which can be a vacuum pump or other device that can generate negative pressure. In addition to the vacuum pump, it can also be other devices, which are not specifically limited here.

[0040] Specifically, during the process of vacuuming the battery cell to generate negative pressure, the electrolyte in the gasified state inside the battery cell enters the cup body 100. Since the inside of the cup body 100 has been cooled by the refrigeration component 200 at this time, the electrolyte maintained in the gasified state will be condensed and liquefied in the cup body 100, so that the gasified electrolyte is converted into liquid. The liquid electrolyte will flow back to the battery cell through the loop formed between the first connecting tube 300 and the battery cell filling port, ensuring that the electrolyte inside the battery cell remains unchanged before and after the formation process.

[0041] In this embodiment, in order to facilitate the liquid electrolyte in the cup body 100 to flow back into the battery cell smoothly, the cup body 100 can be located above the battery cell filling port, that is, the height of the cup body 100 is higher than the battery cell filling port. Under the action of gravity, the liquid electrolyte in the cup body 100 will flow downward and eventually flow back into the battery cell through the battery cell filling port.

[0042] In this embodiment, the refrigeration element 200 is a ceramic condenser or a semiconductor refrigeration plate.

[0043] The cup body 100 includes a cup shell 110, and the interior of the cup shell 110 defines a accommodating cavity 120. The inlet is a first mounting hole 130 opened on the cup shell 110, and the outlet is a second mounting hole 140 opened on the cup shell 110. The first mounting hole 130 is used for the first connecting tube 300 to be installed and communicated with the accommodating cavity 120, and the second mounting hole 140 is used for the first connecting tube 300 to be installed and communicated with the accommodating cavity 120.

[0044] See Figure 2 As shown, the first connecting tube 300 is connected to the accommodating cavity 120 by being connected and installed with the first mounting hole 130, and the first connecting tube 300 is sealed and connected to the liquid injection port of the battery cell. Accordingly, the second connecting tube 400 is connected to the accommodating cavity 120 by being installed and connected with the second mounting hole 140, and the second connecting tube 400 is connected to the vacuum equipment; the passage formed by the second connecting tube 400, the second mounting hole 140, the accommodating cavity 120, the first mounting hole 130, the first connecting tube 300 and the liquid injection port of the battery cell The interior of the battery cell is vacuumed by the passage, and the temperature rises. The gaseous electrolyte inside the battery cell will enter the accommodating cavity 120 through the passage formed by the first connecting tube 300 and the first mounting hole 130. Since the accommodating cavity 120 has been cooled by the refrigeration component 200, the gaseous electrolyte will change from gas to liquid when entering the accommodating cavity 120. The liquid electrolyte will finally flow back to the battery cell through the first connecting tube 300, thereby reducing the loss of the electrolyte in the formation process and preventing the gaseous electrolyte from being drawn away during vacuuming.

[0045] The existing second mounting hole 140 is usually coaxially arranged with the first mounting hole 130. If there is a large amount of liquid electrolyte in the battery cell during the vacuum negative pressure process, the liquid electrolyte will be directly drawn into the accommodating cavity 120. If the negative pressure is drawn too quickly, the second mounting hole 140 is coaxially arranged with the first mounting hole 130 and there is no buffer barrier for the liquid electrolyte. In this case, the liquid electrolyte will be directly drawn out through the second mounting hole 140, and the electrolyte will be changed from an effective electrolyte to a waste liquid, which will affect the battery cell. At the same time, the loss of electrolyte will increase the loss cost.

[0046] In this embodiment, in order to prevent the liquid electrolyte from being directly extracted in large quantities, the second mounting hole 140 and the first mounting hole 130 are set on different axes. Specifically, the second mounting hole 140 is set on the side wall of the cup shell 110, and the first mounting hole 130 is set on the bottom wall of the cup shell 110. Furthermore, the central axis of the second mounting hole 140 is set at a ninety-degree vertical angle to the central axis of the first mounting hole 130. If the negative pressure is drawn out too quickly, the drawn-out electrolyte will first collide with the inner top wall of the cup shell 110, and the electrolyte will be effectively buffered, thereby reducing the direct extraction of liquid electrode liquid due to excessive pumping speed during the negative pressure pumping process.

[0047] The accommodating cavity 120 includes a first cavity 121 and a second cavity 122 . The first mounting hole 130 is connected to the second cavity 122 . The cross section of the second cavity 122 gradually increases from the first mounting hole 130 toward the first cavity 121 . The second cavity 122 is tapered.

[0048] Continue reading Figure 1 and Figure 2 As shown, in order to enable the liquid electrolyte in the accommodating cavity 120 to flow back smoothly into the battery cell, the cross-section of the second cavity 122 can be increased from bottom to top until it is the same size as the cross-section of the first cavity 121. In this embodiment, the shape of the second cavity 122 is conical, that is, the upper opening is large and the lower opening is small, which facilitates the backflow of the liquid electrolyte.

[0049] The cup body 100 is provided with a heat sink 500 for dissipating heat from the refrigeration element 200 . The heat sink 500 includes a connecting plate 510 fixedly mounted on the cup body 100 . The connecting plate 510 contacts the refrigeration element 200 and is provided with heat sinks 520 .

[0050] See Figure 2 and Figure 3 As shown, the refrigeration component 200 is arranged on the upper surface of the cup shell 110. The refrigeration component 200 cools and cools the accommodating cavity 120 inside the cup shell 110 to liquefy the gaseous electrolyte. However, the refrigeration component 200 will generate a certain amount of heat during the refrigeration process. For this reason, the refrigeration component 200 needs to dissipate heat. The heat dissipation of the refrigeration component 200 is achieved by the contact between the heat dissipation component 500 and the refrigeration component 200.

[0051] In this embodiment, the heat sink 500 is composed of a connecting plate 510 and a heat sink 520. The connecting plate 510 is mainly fixed to the upper surface of the cup shell 110. Specifically, the connecting plate 510 can be fixed to the cup shell 110 by screws. A number of evenly distributed heat sinks 520 are provided on the upper surface of the connecting plate 510. The heat sink 520 increases the contact area with the outside and improves the heat dissipation effect.

[0052] For example, the connecting plate 510 and the heat sink 520 can be integrally formed, and thermal grease can be coated on the surface of the refrigeration component 200 in contact with the connecting plate 510 to improve the heat dissipation effect. The connecting plate 510 and the heat sink 520 are made of materials with good thermal conductivity, for example: the thermal conductive material is copper, aluminum and other materials. Of course, in addition to copper and aluminum, other materials that can achieve thermal conductivity can also be used, and the specific details are not limited here.

[0053] In this embodiment, the heat sink 500 can refer to the existing heat sink fin structure, which mainly includes a contact plate and fins that are in contact with the heat dissipated object (the refrigeration element 200 in this application). The heat sink fin structure will not be described in detail here.

[0054] The cup body 100 is installed with a fixing member 600 , and the fixing member 600 is used to fix the cup body 100 . The fixing member 600 includes a fixing plate 610 , and the fixing plate 610 is provided with N connecting holes 620 , satisfying: N ≥ 1.

[0055] Continue reading Figure 3 As shown, the cup body 100 needs to be fixed during the formation process to prevent it from moving. Specifically, the cup body 100 is set on the fixed plate 610 and then fixedly connected to other components through the connecting hole 620. Specifically, in this embodiment, there are two connecting holes 620, that is, N is 2, and the two connecting holes 620 are respectively located on both sides of the cup body 100.

[0056] The cross-section of the cup body 100 is circular, elliptical or polygonal; the shape of the cup body 100 can be designed as needed, and the cross-section of the cup body 100 can be circular or elliptical; when the cup body 100 is polygonal, it can specifically be a triangle, a quadrilateral, a pentagon, a hexagon, etc. In this embodiment, the cross-section of the cup body 100 is rectangular, that is, the whole is a cuboid. Furthermore, the bottom of the cup body 100 is conical, specifically a quadrangular pyramid; furthermore, when the cross-section of the cup body 100 is a pentagon, a hexagon, etc., the bottom is a pentagonal pyramid, a hexagonal pyramid, etc.

[0057] The cup body 100 is provided with a scale (not shown in the figure), through which the amount of liquid that may exist in the cup body 100 can be observed. Specifically, the scale value is milliliter.

[0058] The present application provides a battery cell, which has a liquid injection port, and the liquid injection port is connected to any of the negative pressure cups described above. Any of the negative pressure cups described above is used to prevent the electrolyte in the battery cell from decreasing during the formation process. For details on how to prevent the electrolyte inside the battery cell from decreasing, please refer to the above-mentioned negative pressure cup part, which will not be repeated here.

[0059] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0060] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A negative pressure cup, characterized in that: include: A cup body (100), wherein the cup body (100) has an inlet and an outlet; a refrigeration element (200), the refrigeration element (200) being fixedly mounted on the cup body (100), and the refrigeration element (200) being used to cool the interior of the cup body (100); a first connecting pipe (300), the first connecting pipe (300) being installed at the inlet; A second connecting pipe (400) is installed at the outlet.

2. The negative pressure cup according to claim 1, characterized in that: The cup body (100) includes a cup shell (110), and the interior of the cup shell (110) defines a receiving cavity (120). The inlet is a first mounting hole (130) provided on the cup shell (110), and the outlet is a second mounting hole (140) provided on the cup shell (110). The first mounting hole (130) is used for the first connecting tube (300) to be installed and communicated with the receiving cavity (120), and the second mounting hole (140) is used for the first connecting tube (300) to be installed and communicated with the receiving cavity (120).

3. The negative pressure cup according to claim 2, characterized in that: The accommodating cavity (120) comprises a first cavity (121) and a second cavity (122); the first mounting hole (130) is connected to the second cavity (122); and the cross-section of the second cavity (122) gradually increases from the first mounting hole (130) toward the first cavity (121).

4. The negative pressure cup according to claim 3, characterized in that: The second cavity (122) is conical.

5. The negative pressure cup according to claim 1, characterized in that: A heat dissipation element (500) is installed on the cup body (100), and the heat dissipation element (500) is used to dissipate heat from the refrigeration element (200). The heat dissipation element (500) includes a connecting plate (510) fixedly installed on the cup body (100), the connecting plate (510) is in contact with the refrigeration element (200), and a heat dissipation fin (520) is provided on the connecting plate (510).

6. The negative pressure cup according to claim 1, characterized in that: The cup body (100) is installed with a fixing member (600), and the fixing member (600) is used to fix the cup body (100). The fixing member (600) includes a fixing plate (610), and the fixing plate (610) is provided with N connection holes (620), satisfying: N≥1.

7. The negative pressure cup according to claim 1, characterized in that: The refrigeration element (200) is a ceramic condensing plate or a semiconductor refrigeration plate.

8. The negative pressure cup according to claim 1, characterized in that: The cross section of the cup body (100) is circular, elliptical or polygonal.

9. The negative pressure cup according to claim 1, characterized in that: The cup body (100) is provided with a scale.

10. A battery cell, characterized in that: The battery cell has a liquid injection port, and the liquid injection port is connected to the negative pressure cup according to any one of claims 1 to 9.

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