Liquid-cooled battery cell and battery

Abstract

The utility model relates to the technical field of battery cell structures, and particularly provides a liquid cooling battery cell and a battery. The liquid-cooled battery cell comprises a roll core and a core rod assembly located in the roll core, two groups of mutually independent liquid-cooled channels are arranged in the core rod assembly, each group of liquid-cooled channels is respectively provided with a liquid inlet and a liquid outlet, the flow directions of cooling liquid in each group of liquid-cooled channels are opposite, and the cross section of the roll core is in a runway shape; the battery comprises the liquid cooling battery cell. According to the utility model, the two groups of liquid cooling channels are arranged in the liquid cooling battery core, so that the cooling liquid forms convection in the liquid cooling battery core, the temperature difference between the liquid inlet end and the liquid outlet end of the liquid cooling battery core can be balanced, and the problem of larger temperature difference between the liquid inlet end and the liquid outlet end of the liquid cooling battery core caused by temperature rise after the cooling liquid absorbs heat is effectively solved; therefore, the liquid-cooled battery cell is good and uniform in heat dissipation, the heat dissipation performance of a battery can be remarkably improved after the battery is assembled, the manufacturing cost is low, grouping and assembling are facilitated, and the liquid-cooled battery cell has great popularization value.

Description

Technical Field

[0001] This utility model relates to the field of battery cell structure technology, and in particular to a liquid-cooled battery cell and battery. Background Technology

[0002] Thermal management has always been a key research focus in the new energy field. Liquid cooling is a common traditional cooling method. Most existing liquid cooling methods achieve thermal management by having a liquid cooling plate or pipe containing coolant contact a flat or curved surface of the battery. This method, however, applies the cooling plate to the side of the cell and cannot directly cool the inside, resulting in poor temperature control. Some batteries use built-in cooling cores for thermal management, such as some cylindrical batteries. These have hollow cores with electrodes and separators wound around them, allowing coolant to circulate within the core for internal cooling. This cooling method offers higher efficiency and better cooling effect. However, it is currently mostly used in cylindrical batteries, and the fit between these cores and the casing or cover requires high tolerances, making integrated machining of the parts difficult.

[0003] The applicant previously proposed a rapid temperature-controlled lithium-ion battery with an overall square structure. The cell contains a flat core rod with several liquid-cooling channels through which coolant flows to cool the cell. However, one end of each channel is an inlet and the other an outlet. The coolant enters at a lower temperature and exits at a higher temperature, resulting in inconsistent cooling at both ends of the core rod and a significant temperature difference between the two ends of the cell. Furthermore, the existing coolant collector assembly is structurally complex, leading to complex manufacturing and assembly processes, high production and assembly costs, and low efficiency.

[0004] Therefore, this application is submitted. Utility Model Content

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a liquid-cooled battery cell and battery.

[0006] To achieve the above objectives, the main technical solutions adopted by this utility model include:

[0007] A liquid-cooled battery cell includes: a wound core and a mandrel assembly located therein, the mandrel assembly having two sets of independent liquid-cooling channels, each set of liquid-cooling channels having an inlet and an outlet respectively, and the coolant flowing in opposite directions in each set of liquid-cooling channels, the cross-section of the wound core being racetrack-shaped.

[0008] The core is composed of positive electrode sheet, negative electrode sheet, and separator, which are wound around the core rod assembly in a stacked structure of separator-negative electrode sheet-separator-positive electrode sheet-separator. The positive electrode sheet tabs and negative electrode sheet tabs are on opposite sides during the winding process. The cross-section of the core is racetrack-shaped, which is a special flat structure.

[0009] This invention incorporates two sets of liquid-cooling channels within the liquid-cooled battery cell, enabling convection of the coolant within the cell. Specifically, the outlet of one set of liquid-cooling channels and the inlet of the other set are located at the same end of the core assembly. This design balances the temperature difference between the inlet and outlet of the liquid-cooled battery cell, effectively addressing the issue of a large temperature difference caused by the coolant absorbing heat and increasing its temperature. This prevents localized overheating or insufficient cooling, maintaining temperature consistency across all parts of the battery and improving overall battery performance. Furthermore, when single cells are connected in series or parallel, the connection between the liquid-cooling pipes can be made using a quick-connect method, reducing space requirements, improving assembly efficiency, and simplifying replacement.

[0010] In addition, setting up two sets of liquid cooling channels has the following beneficial effects:

[0011] (1) Improve heat dissipation efficiency

[0012] By setting up two liquid cooling channels, the coolant can form convection within the liquid-cooled cell. The convection effect helps to accelerate the flow rate of the coolant, thereby more effectively removing the heat generated by the battery and improving heat dissipation efficiency.

[0013] (2) Reduce battery temperature

[0014] The convection of coolant not only improves heat dissipation efficiency, but also helps to quickly remove heat, thereby more effectively reducing the battery temperature and ensuring the normal operation of the battery.

[0015] (3) Improve battery performance

[0016] The two liquid cooling channels, through the convection of coolant, can more effectively control the battery's operating temperature, extend its lifespan, and improve its performance.

[0017] Preferably, the two sets of liquid cooling channels do not come into direct contact.

[0018] In the previous embodiment, the two liquid cooling channels can be in contact with each other, or they can be set at a certain distance apart without contacting each other.

[0019] When two liquid cooling channels are in contact with each other, they share a portion of the cooling medium, resulting in more efficient heat transfer. However, this arrangement can also lead to problems. For example, the contact area may become a point of concentrated thermal resistance, restricting the flow of the cooling medium in the contact region and affecting heat dissipation efficiency. Furthermore, improper contact can cause coolant leakage or mixing, impacting the stability and reliability of the entire liquid cooling system. When the two liquid cooling channels are not in contact, they operate independently, with the cooling medium flowing within its own channels without interference. This arrangement avoids the thermal resistance and leakage problems that can arise from contact. Simultaneously, because the two channels are independent, the flow rate and temperature of the cooling medium can be adjusted separately according to actual needs, achieving more precise temperature control. In addition, the non-contact arrangement provides greater design flexibility for the liquid cooling plate, such as easier optimization of the channel layout and increased heat dissipation area.

[0020] Taking all factors into consideration, the two sets of liquid cooling channels are preferably designed to be in a non-direct contact manner.

[0021] Preferably, the mandrel assembly includes a mandrel I and four connectors I. The mandrel I has two sets of independent liquid cooling channels. Each set of liquid cooling channels includes a mandrel body I. The mandrel body I has several liquid passages I, such that one end of the mandrel body I is a liquid inlet and the other end is a liquid outlet. The opposite ends of the mandrel I are respectively provided with grooves, so that the two ends form four ports for connecting with the connectors I. The connectors I include connector bodies I, liquid cooling pipe connection ports I, and mandrel connection ports I. The liquid cooling pipe connection ports I and the mandrel connection ports I are connected through the connector bodies I. The mandrel connection ports I and the ports are structurally matched. After the mandrel connection ports I and the ports are fixedly connected, the liquid cooling pipe connection ports I and the liquid passages I are connected.

[0022] In this embodiment, the two sets of liquid cooling channels are located inside the same mandrel I. The middle part of the mandrel I is solid, and through holes are opened at the top and bottom of the solid part to form two sets of liquid cooling channels. This structural design can enhance the overall structural strength of the mandrel assembly, improve its vibration and impact resistance, and thus enhance the reliability of the system.

[0023] In this embodiment, the design of connector I enables rapid, efficient, and stable injection of coolant into the liquid cooling channel, while also providing structural support to enhance the structural strength of the battery cell, resisting external impacts and vibrations, and ensuring the efficient, safe, and long-term operation of the cooling system. Furthermore, it helps reduce the design complexity, manufacturing cost, and assembly difficulty of other battery components, thereby reducing battery production costs and improving battery production efficiency.

[0024] In this embodiment, the core rod I is generally made of metal, such as aluminum, copper or other high thermal conductivity materials; the connector I is preferably made of the same material as the core rod I, but can also be a composite material, such as metal-coated plastic.

[0025] In a further preferred embodiment, the two opposite end faces of the mandrel I are recessed to form a buffer cavity I that communicates with the liquid passage I.

[0026] In practice, the two end faces of mandrel I are first recessed (for example, only the outer periphery of the end face is retained, while the rest of the end face is recessed) to form two buffer chambers I. Then, a fluid passage is set between the two recessed end faces along the length of mandrel I. Buffer chamber I mainly serves as a pressure balance zone and a flow regulation zone, which helps to distribute the pressure and flow of the coolant in the fluid passage. The coolant is sufficiently decelerated and stabilized before entering the fluid passage, thereby ensuring its smooth flow in the fluid passage and improving heat dissipation efficiency.

[0027] Of course, the specific structure of buffer chamber I is not limited to the above description. Other design methods can also be adopted, such as setting up independent structures at both ends of the liquid passage to construct the buffer chamber.

[0028] In a further preferred embodiment, the liquid cooling pipe connection port I is a cylindrical connector, and the cylindrical connector has at least one sealing ring groove I along its outer circumference. When the liquid cooling pipe connection port I is connected to the liquid cooling pipe, a sealing ring is provided here to ensure the stability of the connection; the mandrel connection port I is provided with a connection cavity I, and the port is wrapped in the connection cavity I.

[0029] Preferably, the mandrel assembly includes two mandrels II and two connectors II; each mandrel II is provided with a liquid cooling channel, the liquid cooling channel including a mandrel body II, the mandrel body II being provided with a plurality of liquid passages II such that one end of the mandrel body II is a liquid inlet and the other end is a liquid outlet; the connector II includes a connector body II, one end of the connector body II is provided with two liquid cooling pipe connection ports II, and the opposite end is provided with a mandrel connection port II, the two liquid cooling pipe connection ports II on the connector body II are arranged at a certain distance apart, the mandrel connection port II is provided with two connecting cavities II respectively communicating with the liquid cooling pipe connection ports II, the two mandrels II are arranged side by side and do not contact each other, and the two ends of the two mandrels II on the same side are respectively fixedly connected by a connector II so that the liquid cooling pipe connection port II is connected to the liquid cooling channel.

[0030] In this embodiment, each of the two core rods II is provided with a set of liquid cooling channels. The two core rods II are arranged side by side and spaced at a certain distance. The two ends of the two core rods II on the same side are fixedly connected by a connector II. The two connectors II combine the two core rods II into a whole.

[0031] In a further preferred embodiment, the two opposite end faces of the mandrel II are recessed to form a buffer cavity II that communicates with the liquid passage II. The function of the buffer cavity II is the same as that of the buffer cavity I.

[0032] In a further preferred embodiment, the liquid cooling pipe connection port II is a cylindrical connection nozzle, and the cylindrical connection nozzle is provided with at least one sealing ring groove II along its outer circumference. The design rationale for the sealing ring groove II is the same as that for the sealing ring groove I. The two ends of the mandrel II are located in the connection cavity II and are fixedly connected to it. The fixed connection method includes, but is not limited to, insertion and welding.

[0033] This utility model also proposes a battery, including: a positive current collector, a positive electrode post assembly, a positive electrode cover plate assembly, a negative current collector, a negative electrode post assembly, a negative electrode cover plate assembly, a housing, and the above-mentioned liquid-cooled battery cell. Except for the liquid-cooled battery cell, the other structural components can be obtained by some adaptive improvements based on the existing technology.

[0034] This invention sets two sets of liquid cooling channels inside the liquid-cooled battery cell, which allows the coolant to convect within the cell. This balances the temperature difference between the inlet and outlet ends of the liquid-cooled battery cell, effectively solving the problem of a large temperature difference between the inlet and outlet ends caused by the coolant absorbing heat and increasing its temperature. Therefore, the liquid-cooled battery cell has good and uniform heat dissipation. When assembled into a battery, it can not only significantly improve the battery's heat dissipation performance, but also facilitate manufacturing and assembly, making it highly practical. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0037] Figure 2 for Figure 1 Exploded view;

[0038] Figure 3 for Figure 1 and Figure 2 Schematic diagram of the structure of core rod I;

[0039] Figure 4 for Figure 3 A schematic diagram of one end of the mandrel I is shown;

[0040] Figure 5 for Figure 4 A cross-sectional view along the ZZ direction;

[0041] Figure 6 for Figure 1 and Figure 2 Schematic diagram of the structure of the middle connector I;

[0042] Figure 7 for Figure 6 Top view;

[0043] Figure 8 for Figure 7 A cross-sectional view along the YY direction;

[0044] Figure 9 for Figure 6 A bottom view;

[0045] Figure 10 This is a schematic diagram of the structure of Embodiment 3 of this utility model;

[0046] Figure 11 for Figure 10 Exploded view;

[0047] Figure 12 for Figure 10 and Figure 11 Schematic diagram of the structure of core rod II;

[0048] Figure 13 for Figure 12 The diagram shows a structural schematic of one end of mandrel II.

[0049] Figure 14 for Figure 13 A sectional view along the XX direction;

[0050] Figure 15 for Figure 10 and Figure 11 Schematic diagram of the structure of the middle connector II;

[0051] Figure 16 for Figure 15 The main view;

[0052] Figure 17 for Figure 15 A sectional view of the main view;

[0053] Figure 18 for Figure 15 Top view;

[0054] Figure 19 for Figure 15 A bottom view;

[0055] Figure 20 This is a schematic diagram of the structure of one embodiment of the battery proposed in this utility model;

[0056] Figure 21 for Figure 20Schematic diagram of the positive electrode current collector;

[0057] Figure 22 for Figure 20 Schematic diagram of the structure of the intermediate negative electrode cover plate assembly Figure 1 ;

[0058] Figure 23 for Figure 20 Schematic diagram of the structure of the intermediate negative electrode cover plate assembly Figure 2 ;

[0059] Figure 24 for Figure 20 The finished product looks like this.

[0060] In the diagram: 1. Mandrel assembly; 11. Mandrel II; 111. Mandrel body II; 112. Liquid passage II; 113. Buffer chamber II; 12. Connector II; 121. Connector body II; 122. Liquid cooling pipe connection port II; 1221. Sealing ring groove II; 123. Mandrel connection port II; 1231. Connection chamber II; 13. Mandrel I; 131. Mandrel body I; 132. Liquid passage I; 133. Buffer chamber I; 14. Connector I; 141. Connector body I; 142. Liquid cooling pipe connection port I; 1421. Sealing ring groove I; 14 3. Core rod connection port I; 1431. Connection cavity I; 2. Core; 3. Positive current collector; 31. Irregular through hole; 32. First groove; 33. Second groove; 34. Immersion through hole; 4. Positive electrode post assembly; 5. Positive electrode cover plate assembly; 6. Negative electrode current collector; 7. Negative electrode post assembly; 8. Negative electrode cover plate assembly; 81. Cover plate body; 82. Sealing ring; 83. Insulating pad; 84. Post sleeve; 85. Injection molded plastic; 86. Explosion-proof valve; 87. Explosion-proof valve diaphragm; 88. Sealing nail; 89. Post through hole; 810. Liquid cooling pipe through hole; 9. Housing. Detailed Implementation

[0061] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0062] The structures not described in detail in the following embodiments are all prior art, and the various directional terms used to clearly describe the component structures are only used to describe their relative positional relationships and are not intended to limit the scope of protection of this utility model.

[0063] Example 1

[0064] This utility model proposes a liquid-cooled battery cell, including: a core 2 and a mandrel assembly 1 located therein. The mandrel assembly 1 is provided with two sets of independent liquid cooling channels. The two sets of liquid cooling channels are arranged at a certain distance apart. Each set of liquid cooling channels is provided with an inlet and an outlet, and the flow direction of the coolant in each set of liquid cooling channels is opposite. The cross-section of the core 2 is racetrack-shaped.

[0065] The specific structure of mandrel assembly 1 is as follows: Figures 1-9 As shown in the figure: the mandrel assembly 1 includes a mandrel I13 and four connectors I14;

[0066] The core rod I13 is provided with two sets of independent liquid cooling channels. Each set of liquid cooling channels includes a core rod body I131. The core rod body I131 is provided with several liquid passages I132, so that one end of the core rod body I131 is a liquid inlet and the other end is a liquid outlet. The opposite ends of the core rod I13 are respectively provided with grooves 135, so that the two ends form four ports for connecting with the connector I14. The opposite end faces of the core rod I13 are recessed to form a buffer cavity I133 communicating with the liquid passages I132.

[0067] The connector I14 includes a connector body I141, a liquid cooling pipe connection port I142, and a mandrel connection port I143. The liquid cooling pipe connection port I142 is a cylindrical connector nozzle, and at least one sealing ring groove I1421 is provided along its outer circumference. The mandrel connection port I143 is provided with a connection cavity I1431. The liquid cooling pipe connection port I142 and the mandrel connection port I143 are connected through the connector body I141. The mandrel connection port I143 matches the port structure. After the mandrel connection port I143 is connected to the port, the port is wrapped in the connection cavity I1431. The liquid cooling pipe connection port I142 is connected to the liquid passage I132.

[0068] Example 2

[0069] like Figures 20-24 This utility model proposes a battery, comprising: a positive electrode current collector 3, a positive electrode terminal assembly 4, a positive electrode cover plate assembly 5, a negative electrode current collector 6, a negative electrode terminal assembly 7, a negative electrode cover plate assembly 8, a casing 9, and as shown in the figure. Figures 1-9 The liquid-cooled battery cell shown.

[0070] The positive current collector 3 has an outer shape that matches the cross-sectional structure of the core 2 and is made of aluminum. A shaped through-hole 31 is formed in the middle of the positive current collector 3. Several elongated, obliquely arranged, and parallel second grooves 33 are distributed above and below the shaped through-hole 31. Several wetting through-holes 34 are formed between adjacent second grooves 33. A first groove 32 for connecting the positive electrode post assembly 4 is provided on one side of the shaped through-hole 31. Both the positive electrode post assembly 4 and the negative electrode post assembly 7 adopt existing technology, and their specific structures are not limited. The negative current collector 6 has a similar structure to the positive current collector 3 and is made of copper. The negative cover plate assembly 8 includes: a cover plate body 81, a sealing ring 82, an insulating gasket 83, an electrode post sleeve 84, and an injection-molded plastic... The electrode sleeve 84 is connected to the cover plate body 81 by injection-molded plastic 85 and sealed by the compression deformation of the sealing ring 82. The insulating gasket 83 is set on the bottom surface of the cover plate body 81. The injection hole is provided with a sealing nail 88. The explosion-proof valve 86 is installed in the explosion-proof valve mounting hole and its surface is covered with an explosion-proof valve film 87. The negative electrode cover plate assembly 8 is also provided with electrode through hole 89, two liquid cooling pipe through holes 810, injection hole and explosion-proof valve mounting hole, etc. The positive electrode cover plate assembly 5 is similar to the negative electrode cover plate assembly 8 except that it does not have injection hole and explosion-proof valve mounting hole. The shell 9 is an extruded integrated structure, whose structure and size match the structure and size of the cell, and both ends are open for installing the corresponding cover plate assembly, etc.

[0071] During assembly, the positive current collector 3 and the negative current collector 6 are laser-welded to the core 2, respectively. The positive electrode post assembly 4 is laser-welded into the first groove 32 of the positive current collector 3, passes through the post through hole on the positive cover plate assembly 5, and is laser-welded to the positive electrode post sleeve. The negative electrode post assembly 7 is laser-welded to the negative current collector 6, passes through the post through hole 89 on the negative cover plate assembly 8, and is laser-welded to the negative electrode post sleeve. The variable connector 12 adjacent to the negative cover plate assembly 8 passes through the liquid cooling pipe through hole 810 and is laser-welded to the cover plate body 81 to achieve a fixed connection between the core rod 11 and the negative cover plate assembly 8, thus isolating the inside and outside of the core rod 11. The cover plate body 81 is laser-welded to the aluminum shell 9. The variable connector 12 on the other side is connected in the same way, ultimately achieving overall sealing. Overall, the battery has high production efficiency, low production cost, and low assembly and grouping difficulty.

[0072] Example 3

[0073] This utility model proposes a liquid-cooled battery cell, including: a core 2 and a mandrel assembly 1 located therein. The mandrel assembly 1 is provided with two sets of independent liquid cooling channels. The two sets of liquid cooling channels are arranged at a certain distance apart. Each set of liquid cooling channels is provided with an inlet and an outlet, and the flow direction of the coolant in each set of liquid cooling channels is opposite. The cross-section of the core 2 is racetrack-shaped.

[0074] The specific structure of mandrel assembly 1 is as follows: Figures 10-19 As shown in the figure: the mandrel assembly 1 includes two mandrels II 11 and two connectors II 12;

[0075] Each core rod II11 is provided with a liquid cooling channel, the liquid cooling channel includes the core rod body II111, the core rod body II111 is provided with a number of liquid passages II112, such that one end of the core rod body II111 is the liquid inlet end and the other end is the liquid outlet end, and the opposite end faces of the core rod II11 are recessed to form a buffer cavity II113 that communicates with the liquid passages II112;

[0076] The connector II12 includes a connector body II121. One end of the connector body II121 is provided with two liquid cooling pipe connection ports II122, and the opposite end is provided with a mandrel connection port II123. The liquid cooling pipe connection port II122 is a cylindrical connection nozzle. The cylindrical connection nozzle is provided with at least one sealing ring groove II1221 along its outer circumference. The mandrel connection port II123 is provided with two connection cavities II1231 that are respectively connected to the liquid cooling pipe connection ports II122. The structure of the connection cavity II1231 matches the structure of the free end of the mandrel II11 so that the free end can be inserted. The two mandrels II11 are arranged side by side and spaced a certain distance apart without contacting each other. The two ends of the two mandrels II11 on the same side are respectively fixedly connected by a connector II12 so that the liquid cooling pipe connection port II122 is connected to the liquid cooling channel.

[0077] Example 4

[0078] This utility model proposes a battery, comprising: a positive electrode current collector, a positive electrode terminal assembly, a positive electrode cover plate assembly, a negative electrode current collector, a negative electrode terminal assembly, a negative electrode cover plate assembly, a casing, and as shown in the figure. Figures 10-19 The liquid-cooled battery cell shown.

[0079] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions, and variations to the above embodiments within the scope of the present invention. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples.

Claims

1. A liquid-cooled battery cell, comprising: The core (2) and the mandrel assembly (1) located therein are characterized in that the mandrel assembly (1) is provided with two sets of independent liquid cooling channels, each set of liquid cooling channels is provided with an inlet and an outlet, and the flow direction of the coolant in each set of liquid cooling channels is opposite, and the cross-section of the core (2) is racetrack shaped.

2. The liquid-cooled battery cell according to claim 1, characterized in that, The two sets of liquid cooling channels are set at a certain distance apart.

3. The liquid-cooled battery cell according to claim 2, characterized in that, The mandrel assembly (1) includes a mandrel I (13) and four connectors I (14); The core rod I (13) is provided with two sets of independent liquid cooling channels. Each set of liquid cooling channels includes a core rod body I (131). The core rod body I (131) is provided with several liquid passages I (132) so that one end of the core rod body I (131) becomes the liquid inlet and the other end becomes the liquid outlet. The two opposite ends of the core rod I (13) are respectively provided with grooves (135) so that the two ends form four ports for connecting with the connector I (14). The connector I (14) includes a connector body I (141), a liquid cooling pipe connection port I (142), and a mandrel connection port I (143). The liquid cooling pipe connection port I (142) and the mandrel connection port I (143) are connected through the connector body I (141). The mandrel connection port I (143) matches the port structure. After the mandrel connection port I (143) is connected to the port, the liquid cooling pipe connection port I (142) is connected to the liquid passage I (132).

4. The liquid-cooled battery cell according to claim 3, characterized in that, The two end faces of the mandrel I (13) are recessed to form a buffer cavity I (133) that communicates with the liquid passage I (132).

5. The liquid-cooled battery cell according to claim 3, characterized in that, The liquid cooling pipe connection port I (142) is a cylindrical connection nozzle. The cylindrical connection nozzle is provided with at least one sealing ring groove I (1421) along its outer circumference. The mandrel connection port I (143) is provided with a connection cavity I (1431). The port is wrapped in the connection cavity I (1431).

6. The liquid-cooled battery cell according to claim 1, characterized in that, The mandrel assembly (1) includes two mandrels II (11) and two connectors II (12); Each core rod II (11) is provided with a liquid cooling channel, the liquid cooling channel includes a core rod body II (111), and a number of liquid passage channels II (112) are provided in the core rod body II (111) so that one end of the core rod body II (111) becomes the liquid inlet and the other end becomes the liquid outlet. The connector II (12) includes a connector body II (121). One end of the connector body II (121) is provided with two liquid cooling pipe connection ports II (122), and the opposite end is provided with a mandrel connection port II (123). The mandrel connection port II (123) is provided with two connecting cavities II (1231) that are respectively connected to the liquid cooling pipe connection port II (122). The two mandrels II (11) are arranged side by side and do not contact each other. The two ends of the two mandrels II (11) on the same side are respectively fixedly connected by a connector II (12) so that the liquid cooling pipe connection port II (122) is connected to the liquid cooling channel.

7. The liquid-cooled battery cell according to claim 6, characterized in that, The two end faces of the mandrel II (11) are recessed to form a buffer cavity II (113) that communicates with the liquid passage II (112).

8. The liquid-cooled battery cell according to claim 6, characterized in that, The liquid cooling pipe connection port II (122) is a cylindrical connection nozzle, and at least one sealing ring groove II (1221) is provided along its outer circumference. The two ends of the mandrel II (11) are located in the connection cavity II (1231).

9. A battery, characterized in that, include: Positive current collector, positive terminal assembly, positive cover plate assembly, negative current collector, negative terminal assembly, negative cover plate assembly, housing, and liquid-cooled battery cell as described in any one of claims 3-5.

10. A battery, characterized in that, include: Positive current collector, positive terminal assembly, positive cover plate assembly, negative current collector, negative terminal assembly, negative cover plate assembly, housing, and liquid-cooled battery cell as described in any one of claims 6-8.

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