Secondary battery and battery pack

Abstract

The present application relates to the technical field of batteries, and discloses a secondary battery and a battery pack. The secondary battery comprises a casing, a top cover assembly, a jelly roll, and a cooling assembly. The casing is provided with an accommodating cavity. The accommodating cavity forms a first opening in the casing. The top cover assembly comprises a top cover sheet, and the top cover sheet is connected to the casing and seals the first opening. The jelly roll is provided in the accommodating cavity. The cooling assembly comprises a liquid cooling plate and a flow guide member, wherein the liquid cooling plate is provided in the accommodating cavity and is fit with the jelly roll, the liquid cooling plate is provided with a flow channel, the flow guide member passes through the top cover sheet, and the liquid cooling plate is located on the side of the flow guide member close to the jelly roll. The flow guide member is electrically connected to the top cover sheet, the flow guide member is electrically connected to the liquid cooling plate, the flow guide member is communicated with the flow channel, and the flow guide member is used for connecting to a thermal management component. In the present application, the flow guide member is configured so that a heat exchange medium in the liquid cooling plate can flow to the outside of the secondary battery for heat exchange, and in addition, the flow guide member electrically connected to the top cover sheet can also enable the liquid cooling plate to maintain a high potential, thereby preventing electrochemical corrosion of the liquid cooling plate.

Description

Secondary batteries and battery packs

[0001] Cross-references to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 202421673424.X, entitled "Secondary Battery and Battery Pack", filed on July 15, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of battery technology, specifically relating to a secondary battery and battery pack. Background Technology

[0004] As the capacity of secondary batteries increases, their thickness also increases, leading to poorer heat dissipation of the internal winding core. Current technology addresses this by placing a liquid cooling plate inside the secondary battery to facilitate heat exchange and remove the heat generated by the winding core.

[0005] However, the liquid cooling plate located inside the secondary battery will be continuously damaged by electrochemical corrosion due to its long-term presence inside the battery, resulting in a shorter-than-expected lifespan for the secondary battery. Summary of the Invention

[0006] The purpose of this disclosure is to provide a secondary battery to solve the technical problem of electrochemical corrosion of the liquid cooling plate located inside the secondary battery; another purpose of this application is to provide a battery pack.

[0007] Technical solution: This application provides a secondary battery, comprising:

[0008] A housing having a receiving cavity, the receiving cavity forming a first opening in the housing;

[0009] A top cover assembly, the top cover assembly including a top cover sheet, the top cover sheet being connected to the housing and sealing the first opening;

[0010] A winding core, wherein the winding core is disposed in the receiving cavity;

[0011] A cooling assembly, comprising a liquid cooling plate and a flow guide, wherein the liquid cooling plate is disposed in the receiving cavity and is attached to the winding core, and the liquid cooling plate has a flow channel;

[0012] The flow guide is inserted through the top cover plate, and the liquid cooling plate is located on the side of the flow guide closer to the core;

[0013] One end of the flow guide is connected to the flow channel, and the other end of the flow guide is used to connect to the thermal management component;

[0014] The flow guide is electrically connected to the top cover plate and the flow guide is electrically connected to the liquid cooling plate.

[0015] In some embodiments, the top cover plate is provided with a positive terminal and a negative terminal, the negative terminal and the top cover plate being insulated from each other, and the positive terminal and the top cover plate being electrically connected.

[0016] In some embodiments, both the flow guide and the liquid cooling plate are made of conductive material.

[0017] In some embodiments, the surface of the liquid cooling plate is insulated.

[0018] In some embodiments, the surface of the liquid cooling plate is covered or coated with at least one of alumina ceramic, silicone rubber, fluororubber, and Teflon.

[0019] In some embodiments, the secondary battery has a first direction, along which at least one of the liquid cooling plates is disposed between two adjacent winding cores, and the liquid cooling plate is in contact with the two adjacent winding cores.

[0020] In some embodiments, the secondary battery includes two winding cores and a liquid cooling plate. The winding cores have two large surfaces facing away from each other along a first direction, and the liquid cooling plate has two heat dissipation surfaces facing away from each other along the first direction X. The two winding cores are arranged along the first direction, and the liquid cooling plate is arranged on two adjacent winding cores along the first direction. The heat dissipation surfaces of the liquid cooling plate are respectively attached to the large surfaces of the two adjacent winding cores facing the liquid cooling plate.

[0021] In some embodiments, along the first direction, at least one of the liquid cooling plates is disposed between the end core and the housing, and the liquid cooling plate is in contact with the end core.

[0022] In some embodiments, the secondary battery has two liquid cooling plates, which are respectively disposed between the winding core and the housing at the ends along the first direction, and the two liquid cooling plates are respectively used to fit against the surfaces of the winding core facing the housing at both ends along the first direction.

[0023] In some embodiments, the secondary battery has a second direction, along which at least one of the liquid cooling plates is disposed between the winding core and the housing, and the liquid cooling plate is in contact with the winding core, and the first direction intersects the second direction.

[0024] In some embodiments, the secondary battery has two liquid cooling plates, and the winding core has facets that are opposite to each other along a second direction, with the two liquid cooling plates respectively attached to the two facets of the winding core.

[0025] In some embodiments, the liquid cooling plate includes a body having an end face facing the top cover plate; the liquid cooling plate further includes a liquid inlet connector and a liquid outlet connector located on the end face, the liquid inlet connector communicating with the flow channel, and the liquid outlet connector communicating with the flow channel.

[0026] The flow guide includes:

[0027] A liquid inlet pipe, which is connected to the liquid inlet connector;

[0028] The liquid outlet pipe is connected to the liquid outlet connector.

[0029] In some embodiments, the secondary battery has a third orientation;

[0030] The secondary battery includes two of the aforementioned top cover plates;

[0031] The receiving cavity also forms a second opening in the housing, and the first opening and the second opening are opposite to each other along the third direction; the two top cover plates are respectively connected to the housing, and the two top cover plates respectively cover the first opening and the second opening;

[0032] The liquid cooling plate includes a body, which has two end faces that are opposite to each other along the third direction. The two end faces correspond one-to-one with the two top cover plates, and the end faces face the top cover plates.

[0033] The liquid cooling plate further includes a liquid inlet connector and a liquid outlet connector, which are located on the two end faces respectively. The liquid inlet connector is connected to the flow channel, and the liquid outlet connector is connected to the flow channel.

[0034] The flow guide includes:

[0035] A liquid inlet pipe, which is connected to the liquid inlet connector, and the liquid inlet pipe passes through one of the two top cover plates;

[0036] The liquid outlet pipe is connected to the liquid outlet connector and is inserted through the other.

[0037] In some embodiments, the inlet pipe is integrally connected to the top cover plate, and the outlet pipe is integrally connected to the top cover plate.

[0038] In some embodiments, the secondary battery has a third orientation, the core includes a thinned portion and a main body portion, the thinned portion is connected to the main body portion, and the thinned portion is located along the third orientation on the side of the main body portion near the top cover assembly;

[0039] The liquid cooling plate includes a body and at least one protrusion, the protrusion being connected to the body along the first direction;

[0040] The protrusion is fitted with the thinned portion, the body is fitted with at least one of the main body portions, and the first direction and the third direction intersect.

[0041] In some embodiments, the secondary battery further includes at least one temperature detection device connected to the winding core.

[0042] In some embodiments, the core has two large faces that are opposite to each other along a first direction, and the temperature detection device is connected to at least one of the large faces.

[0043] In some embodiments, the liquid cooling plate has a maximum dimension d along the first direction, satisfying: 0.3mm≤d≤5mm.

[0044] Accordingly, this application also provides a battery pack, including a secondary battery as described in any of the above embodiments.

[0045] In some embodiments, the flow guide includes an inlet pipe and an outlet pipe, the battery pack includes a shunt pipe and a manifold pipe, the shunt pipe is connected to at least one of the inlet pipes and is used to introduce the heat exchange medium into the liquid cooling plate, and the manifold pipe is connected to at least one of the outlet pipes and is used to lead the heat exchange medium out of the liquid cooling plate.

[0046] Beneficial Effects: Compared with the prior art, the secondary battery provided in this application includes a casing, a top cover assembly, a winding core, and a cooling assembly. The casing has a receiving cavity with a first opening. The top cover assembly includes a top cover sheet connected to the casing and sealing the first opening. The winding core is disposed in the receiving cavity. The cooling assembly includes a liquid cooling plate and a flow guide. The liquid cooling plate is disposed in the receiving cavity and is attached to the winding core. The liquid cooling plate has a flow channel. The flow guide passes through the top cover sheet, and the liquid cooling plate is located on the side of the flow guide closer to the winding core. The flow guide is electrically connected to the top cover sheet and the liquid cooling plate. One end of the flow guide communicates with the flow channel, and the other end is used to connect to a thermal management component. This application provides a flow guide so that the heat exchange medium in the liquid cooling plate can flow to the outside of the secondary battery for heat exchange. At the same time, the flow guide electrically connected to the top cover sheet also allows the liquid cooling plate to maintain a high potential, thereby preventing the liquid cooling plate from being electrochemically corroded. Attached Figure Description

[0047] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0048] Figure 1 is a schematic diagram of the connection structure between the top cover assembly and the cooling assembly in the secondary battery provided in an embodiment of this application;

[0049] Figure 2 is a schematic diagram of the connection structure of the top cover assembly and the cooling assembly in the secondary battery provided in the embodiment of this application from another angle;

[0050] Figure 3 is a schematic diagram of the structure of the secondary battery before cell assembly according to an embodiment of this application;

[0051] Figure 4 is a schematic diagram of the structure of the battery assembly in the secondary battery provided in the embodiment of this application before it is installed into the housing;

[0052] Figure 5 is a schematic diagram of the structure of the secondary battery provided in an embodiment of this application;

[0053] Figure 6 is a schematic diagram of the battery pack provided in an embodiment of this application;

[0054] Figure 7 is a schematic diagram of the structure of the liquid cooling plate and the core in a secondary battery provided in an embodiment of this application;

[0055] Figure 8 is a schematic diagram of the arrangement of the liquid cooling plate and the core in a secondary battery provided in an embodiment of this application;

[0056] Figure 9 is a schematic diagram of the structure of the liquid cooling plate and the core in a secondary battery provided in an embodiment of this application;

[0057] Figure 10 is a schematic diagram of the arrangement of the liquid cooling plate and the core in a secondary battery provided in an embodiment of this application;

[0058] Figure 11 is a schematic diagram of the structure of the liquid cooling plate and the core in a secondary battery provided in an embodiment of this application;

[0059] Figure 12 is a schematic diagram of the arrangement of the liquid cooling plate and the winding core in a secondary battery provided in an embodiment of this application;

[0060] Figure 13 is a schematic diagram of the structure of the liquid cooling plate and the core in a secondary battery provided in an embodiment of this application;

[0061] Figure 14 is a schematic diagram of the arrangement of the liquid cooling plate and the core in a secondary battery provided in an embodiment of this application;

[0062] Figure 15 is a schematic diagram of the structure of the liquid cooling plate and the core in a secondary battery provided in an embodiment of this application;

[0063] Figure 16 is a schematic diagram of the arrangement of the liquid cooling plate and the winding core in a secondary battery provided in one embodiment of this application.

[0064] Reference numerals in the attached drawings: 1-Secondary battery, 10-Shell, 11-Receiving cavity, 12-First opening, 13-First sidewall, 14-Second sidewall, 20-Top cover assembly, 21-Top cover sheet, 30-Core, 31-Thinned portion, 32-Main body, 33-Large surface, 34-Small surface, 40-Cooling assembly, 41-Liquid cooling plate, 411-End face, 412-Body body, 413-Protrusion, 414-Liquid inlet connector, 42-Flow guide, 415-Liquid outlet connector, 416-Heat dissipation surface, 421-Liquid inlet pipe, 422-Liquid outlet pipe, 50-Diverter pipe, 60-Combiner pipe. Detailed Implementation

[0065] 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0066] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically limited. 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 indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0067] It should also be noted that in the accompanying drawings of the embodiments of this application, the arrows labeled X, Y, and Z respectively represent the first direction X, the second direction Y, and the third direction Z. The description of this application introduces the first direction X, the second direction Y, and the third direction Z to more clearly express the relative positional relationship involved in the detection method. The first direction X, the second direction Y, and the third direction Z are three relative directions that intersect each other, rather than absolute directions. In practical applications, the first direction X, the second direction Y, and the third direction Z can point to any direction in space, as long as the intersection relationship between them is maintained.

[0068] The following disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure of this application, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit this application.

[0069] As the capacity of the secondary battery increases, the thickness of the secondary battery 1 also increases, resulting in poorer heat dissipation of the internal winding core. Current technology uses liquid cooling plates inside the secondary battery to improve heat dissipation and remove the heat generated by the winding core.

[0070] However, the liquid cooling plate located inside the secondary battery has a low potential. If it is inside the secondary battery for a long time, it will be continuously electrochemically corroded, causing damage to the liquid cooling plate and making the service life of the secondary battery shorter than expected.

[0071] Please refer to Figures 1, 2, 3, and 4. To address the technical problem of electrochemical corrosion of the liquid cooling plate 41 located inside the secondary battery 1, this application provides a secondary battery 1. Figure 1 is a schematic diagram of the connection structure between the top cover assembly 20 and the cooling assembly 40 in the secondary battery 1 provided in this application embodiment. Figure 2 is a schematic diagram of the connection structure between the top cover assembly 20 and the cooling assembly 40 in the secondary battery 1 provided in this application embodiment from another angle. Figure 3 is a schematic diagram of the structure of the secondary battery before core assembly provided in this application embodiment. Figure 4 is a schematic diagram of the structure of the battery assembly in the secondary battery before it is installed in the housing provided in this application embodiment. The secondary battery 1 includes a housing 10, a top cover assembly 20, a core 30, and a cooling assembly 40. The housing 10 has a receiving cavity 11, and the receiving cavity 11 forms a first opening 12 in the housing 10. The top cover assembly 20 includes a top cover sheet 21, which is connected to the housing 10 and seals the first opening 12. The core 30 is disposed in the receiving cavity 11. The cooling assembly 40 includes a liquid cooling plate 41 and a flow guide 42. The liquid cooling plate 41 is disposed in the receiving cavity 11 and is attached to the core 30. The liquid cooling plate 41 has a flow channel. The flow guide 42 passes through the top cover plate 21, and the liquid cooling plate 41 is located on the side of the flow guide 42 closer to the core 30. The flow guide 42 is electrically connected to the top cover plate 21 and the liquid cooling plate 41. One end of the flow guide 42 communicates with the flow channel, and the other end of the flow guide 42 is used to connect to the thermal management component.

[0072] Specifically, the number of liquid cooling plates 41 can be one or more, and the number of winding cores can also be one or more. When the number of liquid cooling plates 41 is one and the number of winding cores is also one, the liquid cooling plates 41 are located between the winding cores and the housing 10 and are in contact with the winding cores. The liquid cooling plates 41 are disposed inside the housing 10 and are in contact with the winding cores, which can dissipate heat from the winding cores.

[0073] In the above embodiment, by providing a flow guide 42 through the top cover plate 21 and making the flow guide 42 connected to the flow channel, the heat exchange medium in the liquid cooling plate 41 can flow into and out of the secondary battery 1 through the flow guide 42 to achieve heat exchange, thereby removing the heat inside the secondary battery 1 and dissipating heat from the secondary battery more efficiently.

[0074] It should be noted that both the current guide 21 and the liquid cooling plate 41 are made of conductive material. The top cover plate 21 is provided with a positive terminal and a negative terminal. The negative terminal and the top cover plate 21 are insulated from each other, while the positive terminal and the top cover plate 21 are electrically connected. The top cover plate 21 is positively charged. At the same time, the current guide 42 is electrically connected to the liquid cooling plate 41 and the top cover plate 21, so that the liquid cooling plate 41 is also positively charged and thus obtains a higher potential. This avoids the liquid cooling plate 41 from being continuously electrochemically corroded and extends the service life of the secondary battery 1.

[0075] In some embodiments, please refer to Figures 3, 4, and 7-16. Figure 3 is a structural schematic diagram of the secondary battery 1 before core assembly according to an embodiment of this application. Figure 4 is a structural schematic diagram of the secondary battery 1 before the battery assembly is installed in the housing 10 according to an embodiment of this application. Figure 7 is a structural schematic diagram of the liquid cooling plate 41 and the core 30 in the secondary battery 1 according to an embodiment of this application. Figure 8 is a schematic diagram of the arrangement of the liquid cooling plate 41 and the core 30 in the secondary battery 1 according to an embodiment of this application. Figure 9 is a structural schematic diagram of the liquid cooling plate 41 and the core 30 in the secondary battery 1 according to an embodiment of this application. Figure 10 is a schematic diagram of the arrangement of the liquid cooling plate 41 and the core 30 in the secondary battery 1 according to an embodiment of this application. The following are schematic diagrams of the arrangement: Figure 11 is a structural schematic diagram of the liquid cooling plate 41 and the winding core 30 in a secondary battery 1 provided in an embodiment of this application; Figure 12 is a structural schematic diagram of the liquid cooling plate 41 and the winding core 30 in a secondary battery 1 provided in an embodiment of this application; Figure 13 is a structural schematic diagram of the liquid cooling plate 41 and the winding core 30 in a secondary battery 1 provided in an embodiment of this application; Figure 14 is a structural schematic diagram of the liquid cooling plate 41 and the winding core 30 in a secondary battery 1 provided in an embodiment of this application; Figure 15 is a structural schematic diagram of the liquid cooling plate 41 and the winding core 30 in a secondary battery 1 provided in an embodiment of this application; and Figure 16 is a structural schematic diagram of the liquid cooling plate 41 and the winding core 30 in a secondary battery 1 provided in an embodiment of this application. The secondary battery 1 has a first direction X. Along the first direction X, at least one liquid cooling plate 41 is disposed between two adjacent winding cores 30, and the liquid cooling plate 41 is in contact with the two adjacent winding cores 30.

[0076] Specifically, the core 30 has two large surfaces 33 that are opposite to each other along the first direction X, and the liquid cooling plate 41 has two heat dissipation surfaces 416 that are opposite to each other along the first direction X; at least one liquid cooling plate 41 has two heat dissipation surfaces 416 that are respectively attached to the two large surfaces 33 of the core 30.

[0077] In one specific embodiment, please refer again to Figures 3, 4, 7 and 8. The secondary battery 1 includes two winding cores 30 and a liquid cooling plate 41. The two winding cores 30 are arranged along the first direction X. The liquid cooling plate 41 is arranged between two adjacent winding cores 30 along the first direction X. The heat dissipation surface 416 of the liquid cooling plate 41 is respectively attached to the large surface 33 of the two adjacent winding cores 30 facing the liquid cooling plate 41.

[0078] In the above embodiments, there is at least one liquid cooling plate 41 located between two adjacent winding cores 30. The two heat dissipation surfaces 416 of the liquid cooling plate 41 can perform heat exchange simultaneously to achieve the highest working efficiency. That is, when the secondary battery 1 includes a liquid cooling plate 41, the liquid cooling plate 41 must be located between two adjacent winding cores 30.

[0079] In some embodiments, along the first direction X, at least one liquid cooling plate 41 is disposed between the end core 30 and the housing 10, and the liquid cooling plate 41 is in contact with the end core 30.

[0080] Specifically, the housing 10 has first sidewalls 13 that are opposite to each other along the first direction X, and the first sidewalls 13 are used to form a receiving cavity 11; the secondary battery 1 includes at least one liquid cooling plate 41, which is disposed along the first direction X between the end of the winding core 30 and the housing 10, that is, between the first sidewall 13 and the large surface 33, and the liquid cooling plate 41 is used to fit against the large surface 33 of the housing 10 of the end of the winding core 30 along the first direction X, that is, to fit against the large surface 33 of the housing 10 of the winding core 30 close to the housing 10 along the first direction X.

[0081] Furthermore, please refer again to Figures 13 and 14. The secondary battery 1 has two liquid cooling plates 41, which are respectively disposed between the core 30 located at the end along the first direction X and the housing 10. The two liquid cooling plates 41 are respectively used to fit against the large surface 33 of the core 30 at both ends along the first direction X facing the housing 10.

[0082] Although the end core is closer to the outside of the secondary battery 1, in actual use, along the first direction X, the outside of the secondary battery 1 is usually another secondary battery 1, and multiple secondary batteries 1 are attached along the first direction X. This makes heat dissipation of the end core along the first direction X difficult. In the above embodiment, by providing a liquid cooling plate 41 between the housing 10 and the core 30 along the first direction X and making the liquid cooling plate 41 attached to the core 30 to dissipate heat from the end core 30 along the first direction X, the heat dissipation efficiency is further improved.

[0083] In some specific embodiments, the secondary battery 1 has a second direction Y, along which at least one liquid cooling plate 41 is disposed between the winding core 30 and the housing 10, and the liquid cooling plate 41 is in contact with the winding core 30, and the first direction X intersects with the second direction Y.

[0084] Specifically, the winding core 30 has small faces 34 that are opposite to each other along the second direction Y, and the housing 10 has a second sidewall 14 that is opposite to each other along the second direction Y. The second sidewall 14 is used to form a receiving cavity 11. The secondary battery 1 has at least one liquid cooling plate 41, which is located between the winding core 30 and the housing 10 along the second direction Y, that is, between the second sidewall 14 and the small face 34. The heat dissipation surface 416 of the liquid cooling plate 41 is used to fit against the small face 34 of the winding core 30.

[0085] In some specific embodiments, the secondary battery 1 has at least two liquid cooling plates 41 for heat dissipation by bonding the two small faces 34 of the winding core 30 respectively; in other embodiments, the liquid cooling plate 41 is only bonded to one small face 34 of the winding core 30.

[0086] In some specific embodiments, the heat dissipation surface 416 of the liquid cooling plate 41 is in contact with the small facet 34 on one side of all the winding cores 30 in the secondary battery 1; in other embodiments, the heat dissipation surface 416 of the liquid cooling plate 41 is only in contact with the small facet 34 on one side of some of the winding cores 30 in the secondary battery 1, and heat dissipation can be achieved by providing multiple liquid cooling plates 41 on one side of the winding cores 30 along the second direction Y.

[0087] In some specific embodiments, the small facet 34 of the core 30 is a plane, and the heat dissipation surface 416 of the liquid cooling plate 41 located between the small facet 34 and the second side wall 14 is also a plane so as to fit with the small facet 34 of the core 30; in other embodiments, the small facet 34 of the core 30 is a curved surface, and the heat dissipation surface 416 of the liquid cooling plate 41 located between the small facet 34 and the second side wall 14 is also a curved surface so as to fit with the small facet 34 of the core 30.

[0088] In the above embodiment, the heat dissipation effect of this application is further improved by distributing a liquid cooling plate 41 between the second sidewall 14 and the small face 34 to remove the heat from the core 30.

[0089] In some specific embodiments, please refer again to Figures 1 and 2. The liquid cooling plate 41 includes a body 412, which has an end face 411 facing the top cover plate 21. The liquid cooling plate 41 also includes a liquid inlet connector 414 and a liquid outlet connector 415, which are located on the end face 411. The liquid inlet connector 414 is connected to the flow channel, and the liquid outlet connector 415 is connected to the flow channel. The flow guide 42 includes a liquid inlet pipe 421 and a liquid outlet pipe 422, which are connected to the liquid inlet connector 414 and the liquid outlet pipe 422.

[0090] Specifically, the liquid cooling plate 41 includes a body 412, with a flow channel disposed within the body 412. The body 412 has an end face 411 facing the top cover plate 21. The heat exchange medium can flow within the flow channel. Through the liquid outlet connector 415 and the liquid outlet pipe 422, the heat exchange medium in the flow channel can pass through the top cover plate 21 and flow out of the secondary battery 1. Through the liquid inlet connector 414 and the liquid inlet pipe 421, the external heat exchange medium can pass through the top cover plate 21 and enter the secondary battery 1.

[0091] Furthermore, the liquid outlet connector 415 and the liquid outlet pipe 422, and the liquid inlet connector 414 and the liquid inlet pipe 421 can be connected by welding or by threaded connection or other detachable connections; the liquid inlet connector 414 and the body 412 are integrally connected, and the liquid outlet connector 415 and the body 412 are integrally connected; the liquid inlet pipe 421 is integrally connected to the top cover plate 21, and the liquid outlet pipe 422 is integrally connected to the top cover plate 21.

[0092] It should be noted that: integrated connection can be formed in one piece, or it can be assembled into a whole by welding, threading, or other methods.

[0093] In the above embodiment, the heat exchange medium is discharged and the heat is carried out of the secondary battery 1 by setting the liquid outlet connector 415 and the liquid outlet pipe 422, and the heat exchange medium with a lower temperature is introduced into the secondary battery 1 by setting the liquid inlet connector 414 and the liquid inlet pipe 421. After setting the liquid outlet connector 415, the liquid outlet pipe 422, the liquid inlet connector 414 and the liquid inlet pipe 421, the heat exchange medium can circulate between the flow channel and the outside, continuously carrying the heat out of the secondary battery 1.

[0094] In some specific embodiments, please refer again to Figures 15 and 16. The secondary battery 1 has a third direction Z; the secondary battery 1 includes two top cover plates 21; the receiving cavity 11 also forms a second opening in the housing 10, the first opening 12 and the second opening being opposite to each other along the third direction Z; the two top cover plates 21 are respectively connected to the housing 10, and the two top cover plates 21 respectively cover the first opening 12 and the second opening; the liquid cooling plate 41 includes a body 412, the body 412 having two end faces 411 opposite to each other along the third direction Z, the two end faces 411 and the two top cover plates 21 One-to-one correspondence, with end face 411 facing the top cover plate 21; the liquid cooling plate 41 also includes a liquid inlet connector 414 and a liquid outlet connector 415, which are located on two end faces 411 respectively. The liquid inlet connector 414 is connected to the flow channel, and the liquid outlet connector 415 is connected to the flow channel; the flow guide 42 includes a liquid inlet pipe 421 and a liquid outlet pipe 422. The liquid inlet pipe 421 is connected to the liquid inlet connector 414 and passes through one of the two top cover plates 21; the liquid outlet pipe 422 is connected to the liquid outlet connector 415 and passes through the other one.

[0095] Specifically, the liquid cooling plate 41 includes a body 412, which has end faces 411, and the two end faces 411 are opposite to each other along the third direction Z. In the above embodiment, by setting the liquid inlet connector 414 and the liquid outlet connector 415 on the two opposite end faces 411 respectively, the design of the flow channel is more flexible. In addition, the liquid inlet pipe 421 and the liquid outlet pipe 422 are located on the two top cover plates 21 respectively, which can also reduce the area occupied by the flow guide 42 on the top cover plate 21.

[0096] In some specific embodiments, please refer again to Figures 7-16. The secondary battery 1 has a third direction Z. The positive electrode, separator, and negative electrode are wound into a core. The core 30 includes a thinned portion 31 and a main body portion 32. The thinned portion 31 is connected to the main body portion 32. The thinned portion 31 is located on the side of the main body portion 32 near the top cover assembly 20 along the third direction Z. The liquid cooling plate 41 includes a body 412 and at least one protrusion 413. The protrusion 413 is connected to the body 412 along the first direction X. The protrusion 413 is attached to the thinned portion 31, the body 412 is attached to at least one main body portion 32, and the first direction X and the third direction Z intersect.

[0097] During the manufacturing process of the core 30, the end of the coated electrode sheet near the tab is thinner. After the core 30 is formed, a thinned portion 31 is formed at the end of the core 30 near the tab.

[0098] In some specific embodiments, the protrusion 413 also has a flow channel so that the protrusion 413 also has a heat dissipation function.

[0099] In the above embodiment, by providing the protrusion 413 to fill the gap formed between the core 30 and the liquid cooling plate 41 due to the thinning area, the contact area between the liquid cooling plate 41 and the core 30 is increased, resulting in better heat dissipation from the liquid cooling plate 41 to the core 30. Furthermore, because the contact area between the liquid cooling plate 41 and the core 30 is larger, the force exerted on the core 30 by the liquid cooling plate 41 is more uniform, reducing the probability of phenomena such as wrinkling and lithium plating on the electrode sheets, and extending the service life of the secondary battery 1.

[0100] In some specific embodiments, the secondary battery 1 further includes at least one temperature detection device connected to the winding core 30.

[0101] Specifically, a temperature detection device is disposed in the receiving cavity 11. In some embodiments, there are multiple temperature detection devices, each connected to a large surface 33 of a plurality of winding cores 30 to monitor the temperature of each winding core 30. One or more temperature detection devices may be connected to a large surface 33. In other embodiments, the secondary battery 1 includes a temperature detection device connected to the large surface 33 of any winding core 30 to monitor the internal temperature of the secondary battery 1. In some embodiments, the temperature detection device is a temperature sensor.

[0102] The lower-temperature heat exchange medium in the liquid-cooled plate 41 absorbs the heat generated by the higher-temperature winding core 30, and after releasing the heat outside the secondary battery 1, it continues to enter the liquid-cooled plate 41 to absorb the heat generated by the winding core 30 to cool it down. Similarly, if the temperature of the heat exchange medium in the liquid-cooled plate 41 is higher than the temperature of the winding core 30, the liquid-cooled plate 41 can transfer heat to the winding core 30 to heat it.

[0103] In the above embodiments, by setting a temperature detection device, the working temperature of the core 30 can be monitored. When the working temperature of the core 30 is higher than the preset working temperature, the liquid cooling plate 41 cools the core 30 so that the core 30 is at a suitable working temperature, thereby improving the service life and safety performance of the core 30. When the working temperature of the core 30 is lower than the preset working temperature, the liquid cooling plate 41 heats the core 30 so that the core 30 is at a suitable working temperature, thereby improving the service life and safety performance of the core 30.

[0104] In some embodiments, please refer to Figure 16 again, the liquid cooling plate 41 has a maximum dimension d along the first direction X, which satisfies: 0.3mm≤d≤5mm.

[0105] In some specific embodiments, the liquid cooling plate 41 can be made of aluminum, copper, stainless steel, alloys, etc. The guide component 42 and the liquid cooling plate 41 are made of aluminum-manganese alloy to achieve better thermal conductivity, lighter weight, better strength, greater corrosion resistance, and lower cost. Simultaneously, the surface of the liquid cooling plate 41 is insulated; alumina ceramics, silicone rubber, fluororubber, Teflon, etc., can be attached or coated onto the surface.

[0106] In the above embodiments, the maximum size of the liquid cooling plate 41 in the first direction X is set between 0.3 mm and 5 mm, which can prevent the liquid cooling plate 41 from occupying too much space in the secondary battery 1, thereby allowing the thickness of the core 30 to be further increased, thereby improving the energy density of the secondary battery 1.

[0107] Accordingly, this application also provides a battery pack, including a secondary battery 1 as described in any of the above specific embodiments.

[0108] In some specific embodiments, please refer to FIG6. The flow guide 42 includes an inlet pipe 421 and an outlet pipe 422. The battery pack includes a shunt pipe 50 and a manifold 60. The shunt pipe 50 is connected to at least one inlet pipe 421 and is used to introduce the heat exchange medium into the liquid cooling plate 41. The manifold 60 is connected to at least one outlet pipe 422 and is used to lead the heat exchange medium out of the liquid cooling plate 41.

[0109] Furthermore, the battery pack also includes a thermal management component, which is connected to the shunt pipe 50 and the manifold 60. The thermal management component is used to cool the heat exchange medium to reduce its temperature, so that the heat exchange medium can continue to remove heat from the secondary battery 1 so that the secondary battery 1 is at a suitable operating temperature.

[0110] In the above embodiments, the heat exchange medium is introduced from the outside or inside of the battery pack by setting the shunt pipe 50, and the heat exchange medium is drawn out from each secondary battery 1 by setting the manifold 60.

[0111] The foregoing has provided a detailed description of the embodiment of this application. Specific examples have been used in this application to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. Industrial applicability

[0112] In summary, this disclosure provides a secondary battery and a battery pack. By providing a flow guide, the heat exchange medium in the liquid cooling plate can flow to the outside of the secondary battery for heat exchange. At the same time, the flow guide electrically connected to the top cover plate can also maintain a high potential of the liquid cooling plate, thereby preventing the liquid cooling plate from being electrochemically corroded.

Claims

1. A secondary battery (1), wherein The application relates to a secondary battery (1), which comprises: a shell (10) having a containing cavity (11) which forms a first opening (12) in the shell (10); a top cover assembly (20) comprising a top cover sheet (21) connected with the shell (10) and covering the first opening (12); a winding core (30) arranged in the containing cavity (11); a cooling assembly (40) comprising a liquid cooling plate (41) and a flow guide (42), the liquid cooling plate (41) being arranged in the containing cavity (11) and being attached to the winding core (30), the liquid cooling plate (41) having a flow channel; the flow guide (42) being arranged in the top cover sheet (21), the liquid cooling plate (41) being arranged on the side of the flow guide (42) close to the winding core (30); one end of the flow guide (42) being connected to the flow channel, and the other end of the flow guide (42) being used for connecting a heat management component; the flow guide (42) being electrically connected to the top cover sheet (21), and the flow guide (42) being electrically connected to the liquid cooling plate (41).

2. The secondary battery (1) according to claim 1, wherein The top cover sheet (21) is provided with a positive electrode post and a negative electrode post, the negative electrode post is insulatedly connected with the top cover sheet (21), and the positive electrode post is conductively connected with the top cover sheet (21).

3. The secondary battery (1) according to claim 1, wherein The flow guide (42) and the liquid cooling plate (41) are both made of conductive materials.

4. The secondary battery (1) according to claim 1, wherein The surface of the liquid cooling plate (41) is subjected to insulation treatment.

5. The secondary battery (1) according to claim 4, wherein The surface of the liquid cooling plate (41) is attached or coated with at least one of alumina ceramic, silicone rubber, fluororubber and Teflon.

6. The secondary battery (1) according to claim 1, wherein The secondary battery (1) has a first direction (X), along which at least one liquid cooling plate (41) is arranged between two adjacent winding cores (30) and is attached to the two winding cores (30).

7. The secondary battery (1) according to claim 6, wherein The secondary battery (1) comprises two winding cores (30) and one liquid cooling plate (41), the winding core (30) has two large surfaces (33) which are away from each other along the first direction (X), the liquid cooling plate (41) has two heat dissipation surfaces (416) which are away from each other along the first direction (X), the two winding cores (30) are arranged along the first direction (X), the liquid cooling plate (41) is arranged between the two winding cores (30) along the first direction (X), and the heat dissipation surfaces (416) of the liquid cooling plate (41) are respectively attached to the large surfaces (33) of the two winding cores (30) which face the liquid cooling plate (41).

8. The secondary battery (1) according to claim 6, wherein Along the first direction (X), at least one liquid cooling plate (41) is arranged between the winding core (30) at the end and the shell (10), and the liquid cooling plate (41) is attached to the winding core (30) at the end.

9. The secondary battery (1) according to claim 8, wherein The secondary battery (1) has two liquid cooling plates (41), and the winding core (30) has two facets (34) facing away from each other along a second direction (Y), and the two liquid cooling plates (41) are respectively attached to the two facets (34) of the winding core (30).

10. The secondary battery (1) according to claim 6, wherein The secondary battery (1) has a second direction (Y), and at least one liquid cooling plate (41) is arranged between the winding core (30) and the shell (10) along the second direction (Y), and the liquid cooling plate (41) is attached to the winding core (30), and the first direction (X) intersects the second direction (Y).

11. The secondary battery (1) according to claim 10, wherein The secondary battery (1) has two liquid cooling plates (41), and the winding core (30) has two facets (34) facing away from each other along a second direction (Y), and the two liquid cooling plates (41) are respectively attached to the two facets (34) of the winding core (30).

12. The secondary battery (1) according to claim 1, wherein The liquid cooling plate (41) comprises a body (412) having an end face (411) facing the top cover sheet (21); the liquid cooling plate (41) further comprises a liquid inlet connector (414) and a liquid outlet connector (415), the liquid inlet connector (414) and the liquid outlet connector (415) are located on the end face (411), the liquid inlet connector (414) is in communication with the flow channel, and the liquid outlet connector (415) is in communication with the flow channel; The flow guide (42) comprises: a liquid inlet pipe (421) in communication with the liquid inlet connector (414); a liquid outlet pipe (422) in communication with the liquid outlet connector (415).

13. The secondary battery (1) according to claim 12, wherein The liquid inlet pipe (421) and the top cover sheet (21) are integrally connected, and the liquid outlet pipe (422) and the top cover sheet (21) are integrally connected.

14. The secondary battery (1) according to claim 1, wherein The secondary battery (1) has a third direction (Z); The secondary battery (1) comprises two top cover sheets (21); The accommodation cavity (11) further forms a second opening in the shell (10), and the first opening (12) and the second opening face away from each other along the third direction (Z); the two top cover sheets (21) are respectively connected to the shell (10), and the two top cover sheets (21) respectively cover the first opening (12) and the second opening; The liquid cooling plate (41) comprises a body (412) having two end faces (411) facing away from each other along the third direction (Z), and the two end faces (411) correspond one-to-one to the two top cover sheets (21), and the end face (411) faces the top cover sheet (21); The liquid cooling plate (41) further comprises an inlet joint (414) and an outlet joint (415), which are respectively located at the two end faces (411), the inlet joint (414) is in communication with the flow channel, and the outlet joint (415) is in communication with the flow channel; The flow guide (42) comprises: An inlet pipe (421) in communication with the inlet joint (414), the inlet pipe (421) penetrating one of the two top cover pieces (21); An outlet pipe (422) in communication with the outlet joint (415), the outlet pipe (422) penetrating the other one.

15. The secondary battery (1) according to claim 6, wherein The secondary battery (1) has a third direction (Z), the winding core (30) comprises a thinning portion (31) and a main body portion (32), the thinning portion (31) is connected with the main body portion (32), and the thinning portion (31) is located on the side of the main body portion (32) close to the top cover assembly (20) along the third direction (Z); The liquid cooling plate (41) comprises a body (412) and at least one protruding portion (413), the protruding portion (413) is connected to the body (412) along the first direction (X); Wherein, the protruding portion (413) is in contact with the thinning portion (31), the body (412) and at least one main body portion (32) are in contact, and the first direction (X) and the third direction (Z) intersect.

16. The secondary battery (1) according to claim 1, wherein The secondary battery (1) further comprises at least one temperature detection device connected to the winding core (30).

17. The secondary battery (1) according to claim 16, wherein The winding core (30) has two large faces (33) facing away from each other along the first direction (X), and the temperature detection device is connected to at least one large face (33).

18. The secondary battery (1) according to claim 1, wherein The liquid cooling plate (41) has a maximum dimension d along the first direction (X), which satisfies: 0.3mm≤d≤5mm.

19. A battery pack, characterized by The secondary battery (1) comprises the secondary battery (1) according to any one of claims 1-8.

20. The battery pack of claim 19, wherein, The flow guide comprises an inlet pipe (421) and an outlet pipe (422), the battery pack comprises a shunt pipe (50) and a converging pipe (60), the shunt pipe (50) is in communication with at least one inlet pipe (421), and the shunt pipe (50) is used for introducing the heat exchange medium into the liquid cooling plate (41); the converging pipe (60) is in communication with at least one outlet pipe (422), and the converging pipe (60) is used for leading the heat exchange medium out of the liquid cooling plate (41).

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