Lithium battery cell and lithium battery pack with immersion cooling

Abstract

The utility model discloses a kind of lithium battery cell and lithium battery package of immersion cooling, its advantage is in that the lithium battery cell includes cover plate, installation boss of positive and negative electrode post and electrolyte injection port are equipped on cover plate, the middle part of the cover plate is equipped with protrusion, the electrolyte injection port is set in protrusion;The top surface of the installation boss and the top end of protrusion are higher than the immersion surface of cooling liquid.This lithium battery cell and lithium battery package compared with related art, with following advantages: when cooling liquid covers the whole lithium battery cell heating area, the risk of cooling liquid seepage into cell interior can be avoided and the problem of incompatible between cell material and cooling liquid is solved, improve the reliability of lithium battery cell in immersion cooling lithium battery package long-term use.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery pack technology, specifically to an immersion-cooled lithium battery cell and lithium battery pack. Background Technology

[0002] Currently, in immersion-cooled lithium battery packs, the entire lithium battery cell is almost completely submerged in coolant. Due to the complexity of lithium battery structural materials, there is a risk of incompatibility with the immersion coolant. This can lead to coolant seeping into the lithium battery cell during long-term use, affecting the normal operation of the cell. Furthermore, incompatible materials may fail and contaminate the immersion coolant during prolonged immersion, potentially causing safety incidents. Utility Model Content

[0003] One technical problem this application aims to solve is to overcome the deficiencies of the above-mentioned related technologies and provide an immersion-cooled lithium battery cell and lithium battery pack that can avoid the risk of coolant seeping into the cell and solve the problem of incompatibility between cell materials and coolant.

[0004] The technical solution adopted to solve the technical problem of this lithium battery cell is as follows: an immersion-cooled lithium battery cell, including a cover plate, on which an electrolyte injection port is provided. The cover plate is provided with mounting bosses for assembling positive and negative electrode posts; The cover plate has a protrusion in the middle, and the electrolyte injection port is located in the protrusion; The top surface of the mounting boss and the top of the protrusion are higher than the immersion surface of the coolant.

[0005] Compared with related technologies, this lithium battery cell has the following advantages: when the coolant covers the entire heat-generating area of ​​the lithium battery cell, it can avoid the risk of coolant seeping into the cell and solve the problem of incompatibility between cell materials and coolant, thereby improving the reliability of the lithium battery cell in the long-term use of immersion-cooled lithium battery packs.

[0006] Preferably, the height of the installed boss is 3-10mm, and the height of the protrusion is 3-10mm. A suitable height ensures that the thickness of the immersion coolant on the lithium battery cell cover maintains the cooling effect; too low a height results in insufficient immersion coolant on the lithium battery cell cover, easily leading to inadequate cooling; too high a height increases the height of the lithium battery pack, occupying more space.

[0007] Preferably, the height of the mounting boss is the same as the height of the protrusion.

[0008] Preferably, the cross-section of the mounting boss is "". "Shaped". Used to form a snap-fit ​​part to facilitate the assembly of electrode posts.

[0009] As an improvement, the composite electrode post with the same structure for both positive and negative electrode posts includes a central electrode post body. The electrode post body protrudes from the mounting boss at both its upper and lower ends, each with radially extending electrode post coatings. A sealing ring is provided between the middle of the electrode post body and the resting portion of the mounting boss. The electrode post coatings provide insulation and protection; the sealing rings prevent coolant from seeping into the housing from the connection between the electrode post body and the mounting boss.

[0010] Preferably, an explosion-proof valve is installed in the middle of the cover plate, and the explosion-proof valve is immersed in the coolant.

[0011] Preferably, the electrolyte injection port is located between the explosion-proof valve and a mounting boss.

[0012] The technical solution adopted by this lithium battery pack to solve the technical problem is as follows: a lithium battery pack, including lithium battery cells with immersion cooling as described above connected in series or in parallel, adjacent immersion cooling lithium battery cells are connected by electrical connecting pieces, and the concave part in the middle of the electrical connecting pieces is immersed in coolant.

[0013] Compared with related technologies, this lithium battery cell has the following advantages: When the coolant covers the entire heat-generating area of ​​the lithium battery cell, it can avoid the risk of coolant seeping into the cell and solve the problem of incompatibility between cell materials and coolant, thus improving the reliability of the lithium battery cell in the long-term use of the immersion-cooled lithium battery pack; the coolant completely soaks the area of ​​the recessed part of the nickel sheet, ensuring that the cooling capacity of the coolant is transferred to the terminal through the nickel sheet, and then to the cell body inside the cell through the tab, thereby reducing the temperature of the cell and effectively cooling the lithium battery cell. Attached Figure Description

[0014] Figure 1 This is a perspective view of three lithium battery cells connected in series in the lithium battery pack of this application.

[0015] Figure 2 This is a cross-sectional view of the lithium battery cell in the lithium battery pack of this application.

[0016] Figure 3 This is a cross-sectional view of two adjacent lithium battery cells in the lithium battery pack of this application. Detailed Implementation

[0017] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] This preferred embodiment is a lithium battery pack (PACK) comprising a plurality of immersed-cooled lithium battery cells 1 connected in series or parallel. For example... Figure 1 The image shows three submerged-cooled lithium battery cells 1 connected in series. Adjacent submerged-cooled lithium battery cells 1 are electrically connected by a recessed electrical connector 2 in the middle.

[0020] Among them, the immersion-cooled lithium battery cell 1, such as Figure 2 and Figure 3 As shown, the device includes a housing 11, a battery cell body 12 (also called a bare battery cell), and a cover plate 13. The cover plate 13 is welded to the housing 11 to encapsulate the battery cell body 12. The battery cell body 12 is provided with a positive electrode tab 14 and a negative electrode tab 15. Electrolyte is injected into the cavity formed by the cover plate 13 and the housing 11 through an electrolyte injection port 133 of a protrusion 132 in the middle of the cover plate 13. The cover plate 13 is provided with two mounting bosses 131 for electrode posts. A positive electrode post 16 and a negative electrode post 17 are respectively mounted on a mounting boss 131. The positive electrode post 16 is connected to the positive electrode tab 14, and the negative electrode post 17 is connected to the negative electrode tab 15. An explosion-proof valve 18 is installed in the middle of the cover plate 13. The top surface of the mounting boss 131 and the top of the protrusion 132 exceed the immersion surface of the coolant, and the explosion-proof valve 18 is completely immersed in the coolant. The electrolyte injection port 133 is located between the explosion-proof valve 18 and a mounting boss 131.

[0021] Preferably, the height of the mounting boss is 3-10mm, and the height of the protrusion is 3-10mm. The height of the mounting boss is the same as the height of the protrusion.

[0022] Preferably, the cross-section of the mounting boss is " The positive electrode post 16 and the negative electrode post 17 are composite electrode posts with the same structure. The composite electrode post includes a middle electrode post body 161. The electrode post body 161 protrudes from the mounting boss 131 and has radially extending electrode post coatings 163 at both its upper and lower ends. A sealing ring 162 is provided between the electrode post body 161 and the mounting boss 131 to prevent coolant from seeping into the housing 11 from the connection between the electrode post body 161 and the mounting boss 131. The electrode post coatings 163 are used to protect the electrode post body 161, and the outer diameter of the upper electrode post coating 163 is larger than that of the lower electrode post coating 163. The diameter of the electrode post body 161 is the same as the diameter of the tab of the connected cell body 12 and is coaxially arranged.

[0023] Preferably, the electrical connector 2 is a nickel sheet, which has strong corrosion resistance and anti-deposition properties; such as Figure 3As shown, the concave portion 21 in the middle of the nickel sheet is immersed in the coolant; the coolant completely submerges the area of ​​the concave portion 21 of the nickel sheet, ensuring that the cooling capacity of the coolant is transferred to the electrode through the nickel sheet, and then to the cell body 12 inside the cell through the electrode tab, thereby reducing the temperature of the cell and effectively cooling the lithium battery cell 1.

[0024] like Figure 2 and Figure 3 As shown, during normal energy storage and generation of the lithium battery pack, the submerged coolant covers the upper surface of the cover plate 13. The coolant can cover the entire heat-generating area of ​​the lithium battery cell 1, maintaining a constant and low temperature in all areas of the lithium battery cell 1. However, the coolant level does not exceed the top surface of the mounting boss 131 and the top of the protrusion 132, thus avoiding the risk of coolant seeping into the lithium battery cell 1 and solving the problem of incompatibility between the cell material and the coolant. When the lithium battery cell 1 experiences abnormal conditions such as thermal runaway, the explosion-proof valve 18 of the cover plate 13 of the lithium battery cell 1 opens, and the submerged coolant flows back into the lithium battery cell 1, directly cooling the cell body 12 and preventing thermal runaway of the lithium battery cell 1 from causing a safety accident.

[0025] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A submersible cooling lithium battery cell, comprising a cover plate, the cover plate having an electrolyte injection port, characterized in that, The cover plate is provided with mounting bosses for assembling positive and negative electrode posts; The cover plate has a protrusion in the middle, and the electrolyte injection port is located in the protrusion; The top surface of the mounting boss and the top of the protrusion are higher than the immersion surface of the coolant.

2. The immersion-cooled lithium battery cell according to claim 1, characterized in that, The height of the installed boss is 3-10mm, and the height of the protrusion is 3-10mm.

3. The immersion-cooled lithium battery cell according to claim 1 or 2, characterized in that, The height of the mounting boss is the same as the height of the protrusion.

4. The immersion-cooled lithium battery cell according to claim 1, characterized in that, The cross-section of the mounting boss is " "shape.

5. The immersion-cooled lithium battery cell according to claim 4, characterized in that, The composite electrode post with the same structure as the positive and negative electrode posts includes a middle electrode post body. The electrode post body protrudes from the upper and lower ends of the mounting boss and is provided with radially extending electrode post coatings. A sealing ring is provided between the middle part of the electrode post body and the resting part of the mounting boss.

6. The immersion-cooled lithium battery cell according to claim 5, characterized in that, An explosion-proof valve is installed in the middle of the cover plate, and the explosion-proof valve is immersed in the coolant.

7. The immersion-cooled lithium battery cell according to claim 1, characterized in that, An explosion-proof valve is installed in the middle of the cover plate, and the explosion-proof valve is immersed in the coolant.

8. The immersion-cooled lithium battery cell according to claim 7, characterized in that, The electrolyte injection port is located between the explosion-proof valve and a mounting boss.

9. A lithium battery pack, comprising lithium battery cells with immersion cooling as described in any one of claims 1 to 7, connected in series or parallel, characterized in that, Adjacent immersion-cooled lithium battery cells are connected by electrical connectors, the recessed portion of which is immersed in the coolant.

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