Secondary battery and battery pack

Abstract

The utility model discloses a secondary battery and a battery pack, and belongs to the technical field of batteries, the secondary battery comprises a shell, a top cover assembly, a roll core and a cooling assembly, the shell is provided with an accommodating cavity, and the accommodating cavity forms a first opening in the shell; the top cover assembly comprises a top cover piece, and the top cover piece is connected with the shell and covers the first opening. The roll core is arranged in the accommodating cavity; the cooling assembly comprises a liquid cooling plate and a flow guide part, the liquid cooling plate is arranged in the containing cavity and attached to the roll core, the liquid cooling plate is provided with a flow channel, the flow guide part penetrates through the top cover piece, and the liquid cooling plate is located on the side, close to the roll core, of the flow guide part; the flow guide part is electrically connected to the top cover piece and the liquid cooling plate, communicates with the flow channel and is used for being connected with a heat management component. According to the secondary battery, the heat exchange medium in the liquid cooling plate can flow to the outside of the secondary battery for heat exchange by arranging the flow guide piece, and meanwhile, the flow guide piece electrically connected with the top cover piece can also enable the liquid cooling plate to keep relatively high potential, so that the liquid cooling plate is prevented from being electrochemically corroded.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a secondary battery and a battery pack. Background Art

[0002] As the capacity of secondary batteries increases, their thickness also increases, and the heat dissipation effect of the core inside the secondary battery becomes worse. In order to improve the heat dissipation effect of the core inside the secondary battery, current technology will place a liquid cooling plate inside the secondary battery to exchange heat with the core inside the secondary battery and remove the heat generated by the core.

[0003] However, the liquid cooling plate located inside the secondary battery will be continuously electrochemically corroded if it is inside the secondary battery for a long time, causing damage to the liquid cooling plate, making the service life of the secondary battery shorter than expected. Utility Model Content

[0004] Purpose of the utility model: The present application provides a secondary battery for solving the technical problem of electrochemical corrosion of a liquid cooling plate located inside the secondary battery; another purpose of the present application is to provide a battery pack.

[0005] Technical solution: This application provides a secondary battery, including:

[0006] A housing, wherein the housing has a receiving cavity, and the receiving cavity forms a first opening in the housing;

[0007] A top cover assembly, the top cover assembly comprising a top cover sheet, the top cover sheet being connected to the housing and covering the first opening;

[0008] a winding core, the winding core being arranged in the accommodating cavity;

[0009] A cooling assembly, the cooling assembly comprising a liquid cooling plate and a flow guide, the liquid cooling plate being disposed in the accommodating cavity and being in contact with the winding core, the liquid cooling plate having a flow channel;

[0010] The guide member is provided through the top cover plate, and the liquid cooling plate is located on a side of the guide member close to the winding core;

[0011] 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;

[0012] The flow guide is electrically connected to the top cover plate, and the flow guide is electrically connected to the liquid cooling plate.

[0013] In some embodiments, the secondary battery has a first direction, and along the first direction, at least one of the liquid cooling plates is disposed between two adjacent winding cores, and the liquid cooling plate is bonded to the two adjacent winding cores.

[0014] In some embodiments, along the first direction, at least one of the liquid cooling plates is disposed between the winding core at the end and the shell, and the liquid cooling plate is in contact with the winding core at the end.

[0015] In some embodiments, the secondary battery has a second direction, along which at least one liquid cooling plate is disposed between the winding core and the shell, and the liquid cooling plate is attached to the winding core, and the first direction intersects the second direction.

[0016] In some embodiments, the liquid cooling plate includes a body having an end surface, the end surface facing the top cover plate; the liquid cooling plate further includes a liquid inlet joint and a liquid outlet joint, the liquid inlet joint and the liquid outlet joint are located on the end surface, the liquid inlet joint is in communication with the flow channel, and the liquid outlet joint is in communication with the flow channel;

[0017] The flow guide comprises:

[0018] a liquid inlet pipe, the liquid inlet pipe being connected to the liquid inlet joint;

[0019] A liquid outlet pipe is connected to the liquid outlet joint.

[0020] In some embodiments, the secondary battery has a third orientation;

[0021] The secondary battery includes two top cover sheets;

[0022] The accommodating cavity further forms a second opening on the shell, and the first opening and the second opening are separated from each other along the third direction; the two top cover sheets are respectively connected to the shell, and the two top cover sheets respectively cover the first opening and the second opening;

[0023] The liquid cooling plate includes a body, the body having two end surfaces that are opposite to each other along the third direction, the two end surfaces corresponding to the two top cover sheets one by one, and the end surfaces facing the top cover sheets;

[0024] The liquid cooling plate further includes a liquid inlet joint and a liquid outlet joint, the liquid inlet joint and the liquid outlet joint are respectively located on the two end surfaces, the liquid inlet joint is communicated with the flow channel, and the liquid outlet joint is communicated with the flow channel;

[0025] The flow guide comprises:

[0026] a liquid inlet pipe, the liquid inlet pipe being connected to the liquid inlet joint and passing through one of the two top cover sheets;

[0027] A liquid outlet pipe is connected to the liquid outlet joint and is passed through the other one.

[0028] In some embodiments, the secondary battery has a third orientation, the winding core includes a skived portion and a main body portion, the skived portion is connected to the main body portion, and the skived portion is located on a side of the main body portion close to the top cover assembly along the third direction;

[0029] The liquid cooling plate includes a body and at least one protrusion, wherein the protrusion is connected to the body along the first direction;

[0030] The protruding portion is in contact with the thinned portion, the main body is in contact with at least one of the main body portions, and the first direction and the third direction intersect.

[0031] In some embodiments, the secondary battery further includes at least one temperature detection device connected to the winding core.

[0032] In some embodiments, the liquid cooling plate has a maximum dimension d along the first direction, satisfying: 0.3 mm ≤ d ≤ 5 mm.

[0033] Correspondingly, the present application also provides a battery pack, comprising a secondary battery as described in any one of the above embodiments.

[0034] In some embodiments, the guide member includes a liquid inlet pipe and a liquid outlet pipe, and the battery pack includes a shunt pipe and a manifold, the shunt pipe is connected to at least one of the liquid inlet pipes, the shunt pipe is used to introduce the heat exchange medium into the liquid cooling plate, the manifold is connected to at least one of the liquid outlet pipes, and the manifold is used to lead the heat exchange medium out of the liquid cooling plate.

[0035] Beneficial effect: Compared with the prior art, the secondary battery provided by the embodiment of the present application includes a shell, a top cover assembly, a winding core, and a cooling assembly. The shell has a receiving cavity, and the receiving cavity forms a first opening in the shell; the top cover assembly includes a top cover sheet, which is connected to the shell and covers the first opening; the winding core is arranged in the receiving cavity; the cooling assembly includes a liquid cooling plate and a flow guide, the liquid cooling plate is arranged in the receiving cavity and is attached to the winding core, the liquid cooling plate has a flow channel, the flow guide is passed through the top cover sheet, and the liquid cooling plate is located on the side of the flow guide close to the winding core; the flow guide is electrically connected to the top cover sheet, the flow guide is electrically connected to the liquid cooling plate, one end of the flow guide is connected to the flow channel, and the other end of the guide is used to connect to the thermal management component. The present application arranges the flow guide to enable the heat exchange medium in the liquid cooling plate to 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 can also keep the liquid cooling plate at a higher potential, thereby preventing the liquid cooling plate from being electrochemically corroded. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0037] Figure 1A schematic diagram of the connection structure between the top cover assembly and the cooling assembly in the secondary battery provided in an embodiment of the present application;

[0038] Figure 2 A schematic diagram of the connection structure of the top cover assembly and the cooling assembly in the secondary battery provided in an embodiment of the present application at another angle;

[0039] Figure 3 A schematic diagram of the structure of a secondary battery before cell assembly provided in an embodiment of the present application;

[0040] Figure 4 A schematic diagram of the structure of a secondary battery provided in an embodiment of the present application before the battery assembly is installed in a housing;

[0041] Figure 5 A schematic structural diagram of a secondary battery provided in an embodiment of the present application;

[0042] Figure 6 A schematic diagram of the structure of the battery pack provided in an embodiment of the present application;

[0043] Figure 7 This is a schematic structural diagram of the liquid cooling plate and winding core in the secondary battery provided in the first embodiment of this application;

[0044] Figure 8 This is a schematic diagram of the arrangement of the liquid cooling plate and the winding core in the secondary battery provided in the first embodiment of this application;

[0045] Figure 9 This is a schematic structural diagram of a liquid cooling plate and a winding core in a secondary battery provided in the second embodiment of the present application;

[0046] Figure 10 A schematic diagram of the arrangement of a liquid cooling plate and a winding core in a secondary battery provided in the second embodiment of the present application;

[0047] Figure 11 A schematic structural diagram of a liquid cooling plate and a winding core in a secondary battery provided in the third embodiment of the present application;

[0048] Figure 12 A schematic diagram of the arrangement of a liquid cooling plate and a winding core in a secondary battery provided in the third embodiment of the present application;

[0049] Figure 13 This is a schematic structural diagram of a liquid cooling plate and a winding core in a secondary battery provided in the fourth embodiment of the present application;

[0050] Figure 14 This is a schematic diagram of the arrangement of the liquid cooling plate and winding core in the secondary battery provided in the fourth embodiment of the present application;

[0051] Figure 15 This is a schematic structural diagram of a liquid cooling plate and a winding core in a secondary battery provided in the fourth embodiment of the present application;

[0052] Figure 16 This is a schematic diagram of the arrangement of the liquid cooling plate and winding core in the secondary battery provided in the fourth embodiment of the present application.

[0053] Figure numerals: 1-secondary battery, 10-shell, 11-accommodating cavity, 12-first opening, 13-first side wall, 14-second side wall, 20-top cover assembly, 21-top cover sheet, 30-winding core, 31-thinning portion, 32-main body, 33-large surface, 34-small surface, 40-cooling assembly, 41-liquid cooling plate, 411-end surface, 412-main body, 413-protrusion, 414-liquid inlet connector, 415-liquid outlet connector, 416-heat dissipation surface, 42-flow guide, 421-liquid inlet pipe, 422-liquid outlet pipe, 50-diverter pipe, 60-collector pipe. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0055] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly specified and specifically limited. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0056] It should also be noted that in the drawings of the embodiments of the present application, the arrows marked X, Y, and Z respectively represent the first direction X, the second direction Y, and the third direction Z. The description of the present application introduces the first direction X, the second direction Y, and the third direction Z to more clearly express the relative position relationship involved in the detection method, wherein the first direction X, the second direction Y, and the third direction Z are three relative directions that intersect with each other, rather than absolute directions. In actual 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 the two is maintained.

[0057] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application.

[0058] As the capacity of the secondary battery 1 increases, its thickness also increases, reducing the heat dissipation efficiency of the winding core 30 within the secondary battery 1. To improve the heat dissipation efficiency of the winding core 30 within the secondary battery 1, a liquid cooling plate 41 is currently placed within the secondary battery 1 to exchange heat with the winding core 30 within the secondary battery 1 and remove the heat generated by the winding core 30.

[0059] However, the liquid cooling plate 41 inside the secondary battery 1 has a low potential. If it is inside the secondary battery 1 for a long time, it will be continuously electrochemically corroded, causing damage to the liquid cooling plate 41, making the service life of the secondary battery 1 less than expected.

[0060] In order to solve the technical problem of electrochemical corrosion of the liquid cooling plate 41 inside the secondary battery 1, the present application provides a secondary battery 1, see Figure 1 and Figure 2 , Figure 1 This 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 an embodiment of the present application. Figure 2The schematic diagram of the connection structure of the top cover assembly 20 and the cooling assembly 40 in the secondary battery 1 provided in an embodiment of the present application at another angle includes a shell 10, a top cover assembly 20, a core 30 and a cooling assembly 40, the shell 10 has a accommodating cavity 11, and the accommodating cavity 11 forms a first opening 12 in the shell 10; the top cover assembly 20 includes a top cover sheet 21, which is connected to the shell 10 and covers the first opening 12; the core 30 is arranged in the accommodating cavity 11; the cooling assembly 40 includes a liquid cooling plate 41 and a guide member 42, the liquid cooling plate 41 is arranged in the accommodating cavity 11 and is attached to the core 30, the liquid cooling plate 41 has a flow channel, the guide member 42 is passed through the top cover sheet 21, and the liquid cooling plate 41 is located on the side of the guide member 42 close to the core 30; the guide member 42 is electrically connected to the top cover sheet 21, the guide member 42 is electrically connected to the liquid cooling plate 41, one end of the guide member 42 is connected to the flow channel, and the other end of the guide member 42 is used to connect to the thermal management component.

[0061] 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 there is only one liquid cooling plate 41 and the number of winding cores is also one, the liquid cooling plate 41 is located between the winding core and the housing 10, and the liquid cooling plate 41 and the winding core are attached. The liquid cooling plate 41 is set inside the housing 10 and attached to the winding core, which can dissipate heat from the winding core.

[0062] In the above embodiment, a flow guide 42 is provided that passes through the top cover sheet 21, and the flow guide 42 is connected to the flow channel so that 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, take away the heat inside the secondary battery 1, and dissipate heat from the secondary battery more efficiently.

[0063] It should be noted that the guide member 42 and the liquid cooling plate 41 are both made of conductive materials, and a positive electrode column and a negative electrode column are provided on the top cover sheet 21. The negative electrode column and the top cover sheet 21 are insulated and connected, and the positive electrode column and the top cover sheet 21 are conductively connected. The top cover sheet 21 is positively charged. At the same time, the guide member 42 is electrically connected to the liquid cooling plate 41 and the top cover sheet 21, so that the liquid cooling plate 41 is also positively charged and obtains a higher electric potential, thereby avoiding continuous electrochemical corrosion of the liquid cooling plate 41 and extending the service life of the secondary battery 1.

[0064] In some embodiments, see Figure 3 、 Figure 4 、 Figures 7-16 , Figure 3 This is a schematic structural diagram of a secondary battery 1 provided in an embodiment of the present application before the cells are closed. Figure 4 This is a structural diagram of the battery assembly in the secondary battery 1 provided in an embodiment of the present application before being installed in the housing 10. Figure 7 This is a schematic structural diagram of the liquid cooling plate 41 and the winding core 30 in the secondary battery 1 provided in the first embodiment of this application. Figure 8This is a schematic diagram of the arrangement of the liquid cooling plate 41 and the winding core 30 in the secondary battery 1 provided in the first embodiment of this application. Figure 9 This is a schematic structural diagram of the liquid cooling plate 41 and the winding core 30 in the secondary battery 1 provided in the second embodiment of the present application. Figure 10 This is a schematic diagram of the arrangement of the liquid cooling plate 41 and the winding core 30 in the secondary battery 1 provided in the second embodiment of this application. Figure 11 This is a schematic structural diagram of the liquid cooling plate 41 and the winding core 30 in the secondary battery 1 provided in the third embodiment of the present application. Figure 12 This is a schematic diagram of the arrangement of the liquid cooling plate 41 and the winding core 30 in the secondary battery 1 provided in the third embodiment of this application. Figure 13 This is a schematic structural diagram of the liquid cooling plate 41 and the winding core 30 in the secondary battery 1 provided in the fourth embodiment of the present application. Figure 14 This is a schematic diagram of the arrangement of the liquid cooling plate 41 and the winding core 30 in the secondary battery 1 provided in the fourth embodiment of this application. Figure 15 This is a schematic structural diagram of the liquid cooling plate 41 and the winding core 30 in the secondary battery 1 provided in the fourth embodiment of the present application. Figure 16 This is a schematic diagram of the arrangement of the liquid cooling plate 41 and the winding core 30 in the secondary battery 1 provided in the fourth embodiment of the present application. The secondary battery 1 has a first direction X. Along the first direction X, at least one liquid cooling plate 41 is arranged between two adjacent winding cores 30, and the liquid cooling plate 41 is in contact with the two adjacent winding cores 30.

[0065] Specifically, the winding core 30 has two large surfaces 33 facing away from each other along the first direction X, and the liquid cooling plate 41 has two heat dissipation surfaces 416 facing away from each other along the first direction X; the two heat dissipation surfaces 416 of at least one liquid cooling plate 41 are respectively attached to the large surfaces 33 of the two winding cores 30.

[0066] The first embodiment provided by this application is as follows, please refer to Figure 3 、 Figure 4 、 Figure 7 and Figure 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 in contact with the large surfaces 33 of the two adjacent winding cores 30 facing the liquid cooling plate 41.

[0067] In the above embodiment, 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 simultaneously perform heat exchange to achieve the highest working efficiency. That is, when the secondary battery 1 includes at least one liquid cooling plate 41 , the liquid cooling plate 41 must be located between two adjacent winding cores 30 .

[0068] In some embodiments, along the first direction X, at least one liquid cooling plate 41 is disposed between the winding core 30 at the end and the housing 10 , and the liquid cooling plate 41 is in contact with the winding core 30 at the end.

[0069] Specifically, the housing 10 has first side walls 13 that face away from each other along a first direction X, and the first side walls 13 are used to enclose the accommodating cavity 11; the secondary battery 1 includes at least one liquid cooling plate 41, which is disposed between the winding core 30 at the end and the housing 10 along the first direction X, that is, between the first side wall 13 and the large surface 33, and the liquid cooling plate 41 is used to fit with the large surface 33 of the housing 10 facing the winding core 30 at the end along the first direction X, that is, to fit with the large surface 33 of the housing 10 facing the winding core 30 close to the housing 10 along the first direction X. Further, in the fourth embodiment provided in this application, please refer again to Figure 13 and Figure 14 The secondary battery 1 has two liquid cooling plates 41, which are respectively arranged between the winding core 30 and the shell 10 at the ends along the first direction X, and the two liquid cooling plates 41 are respectively used to fit with the large surface 33 of the winding core 30 at both ends along the first direction X facing the shell 10.

[0070] Although the winding core 30 at the end is closer to the exterior of the secondary battery 1, in actual use, along the first direction X, the exterior of a secondary battery 1 is often located next to another secondary battery 1. Multiple secondary batteries 1 are closely attached along the first direction X, which makes heat dissipation from the winding core 30 at the end along the first direction X difficult. In the above embodiment, a liquid cooling plate 41 is positioned between the housing 10 and the winding core 30 along the first direction X, and the liquid cooling plate 41 is attached to the winding core 30 to dissipate heat from the winding core 30 at the end along the first direction X, further improving heat dissipation efficiency.

[0071] In some embodiments, the secondary battery 1 has a second direction Y. Along the second direction Y, 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 attached to the winding core 30 . The first direction X intersects the second direction Y.

[0072] Specifically, the core 30 has small faces 34 that are opposite to each other along the second direction Y, and the shell 10 has second side walls 14 that are opposite to each other along the second direction Y. The second side walls 14 are used to enclose the accommodating cavity 11; the secondary battery 1 has at least one liquid cooling plate 41, which is located between the core 30 and the shell 10 along the second direction Y, that is, between the second side wall 14 and the small face 34, and the heat dissipation surface 416 of the liquid cooling plate 41 is used to fit with the small face 34 of the core 30.

[0073] In some embodiments, the secondary battery 1 has at least two liquid cooling plates 41 , respectively used to adhere to the two small surfaces 34 of the winding core 30 for heat dissipation; in other embodiments, the liquid cooling plate 41 only adheres to the small surface 34 on one side of the winding core 30 .

[0074] In some embodiments, the heat dissipation surface 416 of the liquid cooling plate 41 is in contact with the small surface 34 on one side of all the 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 surface 34 on one side of some of the cores 30 in the secondary battery 1. By arranging multiple liquid cooling plates 41 on one side of the core 30 along the second direction Y, heat dissipation of the small surface 34 on one side of all the cores 30 in the secondary battery 1 can be achieved.

[0075] In some embodiments, the small surface 34 of the core 30 is a plane, and the heat dissipation surface 416 of the liquid cooling plate 41 located between the small surface 34 and the second side wall 14 is also a plane to facilitate fitting with the small surface 34 of the core 30; in other embodiments, the small surface 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 surface 34 and the second side wall 14 is also a curved surface to facilitate fitting with the small surface 34 of the core 30.

[0076] In the above embodiment, a liquid cooling plate 41 is provided between the second side wall 14 and the small face 34 to remove the heat of the winding core 30 , thereby further improving the heat dissipation effect of the present application.

[0077] In some embodiments, please refer again to Figure 1 and Figure 2 The liquid cooling plate 41 includes a main body 412, which has an end surface 411, and the end surface 411 faces the top cover plate 21; the liquid cooling plate 41 also includes a liquid inlet joint 414 and a liquid outlet joint 415, which are located on the end surface 411, and the liquid inlet joint 414 is connected to the flow channel, and the liquid outlet joint 415 is connected to the flow channel; the guide member 42 includes a liquid inlet pipe 421 and a liquid outlet pipe 422, and the liquid inlet pipe 421 is connected to the liquid inlet joint 414; the liquid outlet pipe 422 is connected to the liquid outlet joint 415.

[0078] Specifically, the liquid cooling plate 41 includes a main body 412, a flow channel is arranged in the main body 412, and the main body 412 has an end surface 411 facing the top cover plate 21. The heat exchange medium can flow in the flow channel. Through the liquid outlet joint 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 joint 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.

[0079] Furthermore, the liquid outlet joint 415 and the liquid outlet pipe 422, the liquid inlet joint 414 and the liquid inlet pipe 421 can be connected by welding or by a detachable connection such as a threaded connection; the liquid inlet joint 414 and the main body 412 are integrally connected, and the liquid outlet joint 415 and the main body 412 are integrally connected; the liquid inlet pipe 421 and the top cover piece 21 are integrally connected, and the liquid outlet pipe 422 and the top cover piece 21 are integrally connected.

[0080] In the above embodiment, the heat exchange medium is conducted out of the secondary battery 1 and the heat is taken out of the secondary battery 1 by providing the liquid outlet joint 415 and the liquid outlet pipe 422, and the heat exchange medium with a lower temperature is introduced into the secondary battery 1 by providing the liquid inlet joint 414 and the liquid inlet pipe 421. After the liquid outlet joint 415, the liquid outlet pipe 422, the liquid inlet joint 414 and the liquid inlet pipe 421 are provided, the heat exchange medium can circulate between the flow channel and the outside world, continuously taking heat out of the secondary battery 1.

[0081] In some embodiments, please refer again to Figure 15 and Figure 16 , the secondary battery 1 has a third direction Z; the secondary battery 1 includes two top cover sheets 21; the accommodating cavity 11 further forms a second opening on the shell 10, and the first opening 12 and the second opening are separated 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 includes a body 412, and the body 412 has two end surfaces 411 separated along the third direction Z, and the two end surfaces 411 correspond to the two top cover sheets 21 one by one, and the end surfaces 411 face Towards the top cover piece 21; the liquid cooling plate 41 also includes a liquid inlet joint 414 and a liquid outlet joint 415, which are respectively located on the two end surfaces 411, the liquid inlet joint 414 is connected to the flow channel, and the liquid outlet joint 415 is connected to the flow channel; the guide member 42 includes a liquid inlet pipe 421 and a liquid outlet pipe 422, the liquid inlet pipe 421 is connected to the liquid inlet joint 414, and the liquid inlet pipe 421 is arranged on one of the two top cover pieces 21; the liquid outlet pipe 422 is connected to the liquid outlet joint 415, and the liquid outlet pipe 422 is arranged on the other.

[0082] Specifically, the liquid cooling plate 41 includes a body 412 having end surfaces 411, with the two end surfaces 411 facing away from each other along the third direction Z. In the above embodiment, by disposing the liquid inlet connector 414 and the liquid outlet connector 415 on the two facing end surfaces 411, the flow channel design is more flexible. In addition, the liquid inlet pipe 421 and the liquid outlet pipe 422 are respectively located on the two top cover sheets 21, which can also reduce the area occupied by the flow guide member 42 on the top cover sheet 21.

[0083] In some embodiments, please refer again to Figures 7-16The secondary battery 1 has a third direction Z, and the positive electrode sheet, the separator, and the negative electrode sheet are prepared into a roll core 30 by winding. The roll core 30 includes a thinned portion 31 and a main body 32. The thinned portion 31 is connected to the main body 32, and the thinned portion 31 is located on a side of the main body 32 close to the top cover assembly 20 along the third direction Z; the liquid cooling plate 41 includes a main body 412 and at least one protrusion 413, and the protrusion 413 is connected to the main body 412 along the first direction X; wherein the protrusion 413 is in contact with the thinned portion 31, and the main body 412 is in contact with at least one main body 32, and the first direction X and the third direction Z intersect.

[0084] During the production process of the winding core 30 , the end of the electrode sheet close to the electrode tab is thinner after coating. After the winding core 30 is formed, a thinned portion 31 is generated at the end of the winding core 30 close to the electrode tab.

[0085] In some embodiments, the protrusion 413 also has a flow channel, so that the protrusion 413 also has a heat dissipation function.

[0086] In the above embodiment, the protrusion 413 is provided to fill the gap between the winding core 30 and the liquid cooling plate 41 formed by the thinned portion 31. This increases the contact area between the liquid cooling plate 41 and the winding core 30, improving the heat dissipation effect of the liquid cooling plate 41 on the winding core 30. Furthermore, the larger contact area between the liquid cooling plate 41 and the winding core 30 also makes the force exerted by the liquid cooling plate 41 more uniform on the winding core 30, reducing the likelihood of electrode wrinkling and lithium deposition, thereby extending the service life of the secondary battery 1.

[0087] In some embodiments, the secondary battery 1 further includes at least one temperature detection device connected to the winding core 30 .

[0088] Specifically, a temperature detection device is disposed in the accommodating cavity 11. In some embodiments, there are multiple temperature detection devices, each connected to the large surface 33 of the multiple winding cores 30 to monitor the temperature of each winding core 30. One large surface 33 may be connected to one or more temperature detection devices. 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 temperature inside the secondary battery 1. In some embodiments, the temperature detection device is a temperature sensor.

[0089] The cooler heat exchange medium in the cold plate 41 absorbs the heat generated by the hotter core 30. After releasing the heat outside the secondary battery 1, it continues to enter the cold plate 41 to absorb the heat generated by the core 30, thereby cooling the core 30. Similarly, if the temperature of the heat exchange medium in the cold plate 41 is higher than that of the core 30, the cold plate 41 can transfer heat to the core 30, thereby heating it.

[0090] In the above embodiment, by setting up 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.

[0091] In some embodiments, please refer again to Figure 16 The liquid cooling plate 41 has a maximum dimension d along the first direction X, which satisfies: 0.3 mm ≤ d ≤ 5 mm.

[0092] In some embodiments, the liquid cooling plate 41 can be made of aluminum, copper, stainless steel, or alloys. The guide member 42 and the liquid cooling plate 41 are made of an aluminum-manganese alloy to provide excellent thermal conductivity, lightweight, high strength, corrosion resistance, and low cost. The surface of the liquid cooling plate 41 is insulated and can be coated with alumina ceramic, silicone rubber, fluororubber, Teflon, or the like.

[0093] In the above embodiment, the maximum dimension 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 further increasing the thickness of the winding core 30 and improving the energy density of the secondary battery 1.

[0094] Correspondingly, the present application also provides a battery pack, comprising the secondary battery 1 according to any one of the above embodiments.

[0095] In some embodiments, see Figure 6 The guide member 42 includes a liquid inlet pipe 421 and a liquid 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 liquid inlet pipe 421. The shunt pipe 50 is used to introduce the heat exchange medium into the liquid cooling plate 41. The manifold 60 is connected to at least one liquid outlet pipe 422. The manifold 60 is used to lead the heat exchange medium out of the liquid cooling plate 41.

[0096] 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 the temperature of the heat exchange medium so that the heat exchange medium can continue to take away the heat of the secondary battery 1 to keep the secondary battery 1 at a suitable operating temperature.

[0097] In the above embodiment, the shunt pipe 50 is provided to centrally introduce the heat exchange medium from the outside or inside of the battery pack, and the manifold 60 is provided to centrally lead the heat exchange medium out of each secondary battery 1 .

[0098] The above is a detailed introduction to a secondary battery and a battery pack provided in the embodiments of the present application. Specific examples are used in the present application to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A secondary battery, characterized in that: include: A housing, wherein the housing has a receiving cavity, and the receiving cavity forms a first opening in the housing; A top cover assembly, the top cover assembly comprising a top cover sheet, the top cover sheet being connected to the housing and covering the first opening; a winding core, the winding core being arranged in the accommodating cavity; A cooling assembly, the cooling assembly comprising a liquid cooling plate and a flow guide, the liquid cooling plate being disposed in the accommodating cavity and being in contact with the winding core, the liquid cooling plate having a flow channel; The guide member is provided through the top cover plate, and the liquid cooling plate is located on a side of the guide member close to the winding core; 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; The flow guide is electrically connected to the top cover plate, and the flow guide is electrically connected to the liquid cooling plate.

2. The secondary battery according to claim 1, wherein The secondary battery has a first direction. Along the first direction, at least one liquid cooling plate is disposed between two adjacent winding cores, and the liquid cooling plate is attached to the two adjacent winding cores.

3. The secondary battery according to claim 2, wherein Along the first direction, at least one of the liquid cooling plates is disposed between the winding core at the end and the shell, and the liquid cooling plate is in contact with the winding core at the end.

4. The secondary battery according to claim 2, wherein: The secondary battery has a second direction. Along the second direction, at least one liquid cooling plate is disposed between the winding core and the shell, and the liquid cooling plate is attached to the winding core. The first direction intersects the second direction.

5. The secondary battery according to claim 1, wherein The liquid cooling plate includes a body having an end surface, the end surface facing the top cover plate; the liquid cooling plate also includes a liquid inlet joint and a liquid outlet joint, the liquid inlet joint and the liquid outlet joint are located on the end surface, the liquid inlet joint is in communication with the flow channel, and the liquid outlet joint is in communication with the flow channel; The flow guide comprises: a liquid inlet pipe, the liquid inlet pipe being connected to the liquid inlet joint; A liquid outlet pipe is connected to the liquid outlet joint.

6. The secondary battery according to claim 1, wherein The secondary battery has a third orientation; The secondary battery includes two top cover sheets; The accommodating cavity further forms a second opening on the shell, and the first opening and the second opening are separated from each other along the third direction; the two top cover sheets are respectively connected to the shell, and the two top cover sheets respectively cover the first opening and the second opening; The liquid cooling plate includes a body, the body having two end surfaces that are opposite to each other along the third direction, the two end surfaces corresponding to the two top cover sheets one by one, and the end surfaces facing the top cover sheets; The liquid cooling plate further includes a liquid inlet joint and a liquid outlet joint, the liquid inlet joint and the liquid outlet joint are respectively located on the two end surfaces, the liquid inlet joint is communicated with the flow channel, and the liquid outlet joint is communicated with the flow channel; The flow guide comprises: a liquid inlet pipe, the liquid inlet pipe being connected to the liquid inlet joint and passing through one of the two top cover sheets; A liquid outlet pipe is connected to the liquid outlet joint and is passed through the other one.

7. The secondary battery according to claim 2, characterized in that The secondary battery has a third direction, the winding core includes a skived portion and a main body portion, the skived portion is connected to the main body portion, and the skived portion is located on a side of the main body portion close to the top cover assembly along the third direction; The liquid cooling plate includes a body and at least one protrusion, wherein the protrusion is connected to the body along the first direction; The protruding portion is in contact with the thinned portion, the main body is in contact with at least one of the main body portions, and the first direction and the third direction intersect.

8. The secondary battery according to claim 1, wherein The secondary battery further includes at least one temperature detection device connected to the winding core.

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

10. A battery pack, characterized in that: A secondary battery comprising the battery as described in any one of claims 1 to 9.

11. The battery pack according to claim 10, characterized in that: The flow guide comprises a liquid inlet pipe and a liquid outlet pipe, and the battery pack comprises a shunt pipe and a manifold, wherein the shunt pipe is connected to at least one of the liquid inlet pipes. The diverter pipe is used to introduce the heat exchange medium into the liquid cooling plate, and the confluence pipe is connected to at least one of the liquid outlet pipes. The manifold is used to lead the heat exchange medium out of the liquid cooling plate.

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