Battery cell and battery

Abstract

The application relates to a battery monomer and a battery. The battery monomer comprises an end cover, an electrode assembly, a switching piece and a plastic piece. The end cover is provided with a pole. The electrode assembly comprises a heat dissipation surface which is spaced apart from the end cover along the thickness direction of the end cover, and a tab which is protruded on the heat dissipation surface. The switching piece and the plastic piece are arranged between the end cover and the heat dissipation surface. The switching piece is electrically connected with the tab and the pole. The plastic piece is in thermal conductive connection with the end cover, the heat dissipation surface and the switching piece. The technical scheme of the application can increase the heat dissipation path of the heat in the battery monomer to the outside, and improve the heat dissipation effect of the battery monomer.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to battery cells and batteries. Background Technology

[0002] To address battery heat dissipation, related technologies employ a liquid cooling plate on top of the battery cell, along with a thermal pad or conductive adhesive to facilitate heat transfer between the liquid cooling plate and the aluminum foil and the battery cell end cap. For battery cells with adapter plates, the typical heat transfer path is: electrode assembly—tab—adapter plate (if applicable)—terminal post—foil—thermal adhesive / pad—top liquid cooling plate. Along this path, the welding area between the adapter plate, tab, and terminal post is usually small, resulting in low heat transfer efficiency and ineffective cooling of the electrode assembly. Utility Model Content

[0003] Therefore, it is necessary to provide a battery cell and battery to address the problem of poor heat dissipation of the internal electrode components of a battery cell.

[0004] In a first aspect, this application proposes a single battery cell, comprising:

[0005] End cap, on which an pole post is provided;

[0006] The electrode assembly includes a heat dissipation surface spaced relative to the end cap along the thickness direction of the end cap, and an electrode tab protruding from the heat dissipation surface.

[0007] An adapter and a plastic component are arranged between the end cap and the heat dissipation surface; the adapter is electrically connected to the electrode tab and the electrode post, and the plastic component is thermally connected to the end cap, the heat dissipation surface and the adapter.

[0008] In some embodiments, the thermal conductivity of the plastic part is 0.2 to 1 W / (m·K).

[0009] In some embodiments, the plastic part includes a heat-conducting part and a phase change part, the phase change part being enclosed within the heat-conducting part, and the solid-liquid phase change temperature of the phase change part being 50–70°C; the heat-conducting part thermally connects the end cap, the heat dissipation surface, and the adapter.

[0010] In some embodiments, the plastic part includes a first contact portion and a second contact portion adjacent to each other along the thickness direction, the first contact portion being in contact with the end cap surface, and the second contact portion being in contact with the heat dissipation surface.

[0011] The adapter is disposed between the first contact portion and the second contact portion, and is thermally connected to at least one of the first contact portion and the second contact portion.

[0012] In some embodiments, the first contact portion includes a first contact area that is spaced apart from the second contact portion along the thickness direction, an accommodating space is formed between the first contact area and the second contact portion, a first clearance hole communicating with the accommodating space is provided on the first contact area, the pole passes through the first clearance hole and extends into the accommodating space, and the adapter is located in the accommodating space and electrically connected to the pole.

[0013] The adapter located in the accommodating space comes into contact with the second contact surface.

[0014] In some embodiments, a protruding edge is provided on the side of the first contact area away from the second contact portion. The protruding edge surrounds the first clearance hole and thermally connects the end cap and the pole post along the thickness direction.

[0015] In some embodiments, the first contact portion further includes a second contact portion adjacent to the first contact area, the second contact portion being offset from the projection of the second contact portion along the thickness direction, the second contact portion being spaced apart from the heat dissipation surface to form a clearance space, and the tab being located in the clearance space;

[0016] A portion of the adapter is located in the accommodating space and connected to the pole post, while the remaining portion is located in the clearance space and connected to the pole tab. The remaining portion is in contact with the second contact area surface.

[0017] In some embodiments, the end of the first contact portion facing the second contact portion is recessed to form a groove, the accommodating space includes a portion of the groove, and the clearance space includes another portion of the groove.

[0018] In some embodiments, the battery cell further includes a pressure relief structure disposed on the end cap, the plastic part includes a vent hole penetrating the second contact area, and the pressure relief structure is disposed opposite to the vent hole.

[0019] In some embodiments, the plastic part further includes a support portion, which is thermally supported between the second contact area and the heat dissipation surface, and the support portion is disposed around the vent hole.

[0020] In some embodiments, the support includes an enclosure area and a mesh area. The enclosure area is thermally supported between the second contact area and the heat dissipation surface. The mesh area is in contact with the heat dissipation surface. The enclosure area is disposed around the edge of the mesh area and surrounds the vent hole.

[0021] Secondly, this application proposes a battery comprising:

[0022] The battery cell as described in the first aspect;

[0023] Liquid cooling plate;

[0024] A thermally conductive layer, thermally connected between the end cap of the battery cell and the liquid cooling plate; and

[0025] An electrical connector is electrically connected to the terminal of the battery cell, and the thermally conductive layer encapsulates the electrical connector.

[0026] In some embodiments, the electrical connector is provided with fins.

[0027] In some embodiments, the end cap is provided with a pressure relief structure, the heat-conducting layer is provided with an exhaust channel, and the pressure relief structure is located in the exhaust channel.

[0028] In some embodiments, the battery includes a sealant strip located between the liquid cooling plate and a plurality of battery cells, which together enclose a potting space, and the thermally conductive layer is located in the potting space.

[0029] The aforementioned battery cells and batteries, with their plastic components connected to the end caps, heat dissipation surfaces, and adapters, allow heat generated by the electrode assembly to be transferred to the liquid cooling plate not only through the tabs, adapters, terminals, electrical connectors, and thermally conductive layers, but also through the heat dissipation surfaces, plastic components, end caps, and thermally conductive layers. This multi-pathway design significantly improves the heat dissipation performance of the battery cells. Attached Figure Description

[0030] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0031] Figure 1 This is a schematic diagram of the external shape of a battery according to some embodiments;

[0032] Figure 2 for Figure 1 The diagram shown is an exploded view of the battery.

[0033] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0034] Figure 4 This is a schematic diagram of the external shape of a battery cell in some embodiments;

[0035] Figure 5 for Figure 4 The diagram shows an exploded view of a single battery cell.

[0036] Figure 6 This is a schematic diagram of the internal structure of a battery cell in some embodiments;

[0037] Figure 7 This is a schematic diagram of the external shape of a plastic part according to some embodiments;

[0038] Figure 8 for Figure 7 Another view of the plastic part shown;

[0039] Figure 9 for Figure 7 A cross-sectional schematic diagram of the plastic part shown;

[0040] Figure 10 for Figure 9 Another view of the structure.

[0041] The reference numerals in the detailed embodiments are as follows: 1000, battery; 100, battery cell; 10, end cap; 11, terminal post; 11a, end head; 12, pressure relief structure; Z, thickness direction; Y, length direction; X, width direction; 20, electrode assembly; 21, heat dissipation surface; 22, electrode tab; 30, adapter; 40, plastic part; 41, first contact part; 41a, first contact area; k1, accommodating space; a1, first clearance hole; a2, protruding edge; a3, groove; 41b, second contact area; k2, clearance space; 41c, support part; c1, enclosing area; c2, mesh area; h, vent hole; 42, second contact part; 50, sealing ring; 60, shell; a4, second clearance hole; 200, liquid cooling plate; 300, thermally conductive layer; 301, exhaust channel; 400, electrical connector; 401, fin. Detailed Implementation

[0042] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0043] In the description of this application, it should be understood that, where they appear, the terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0044] Furthermore, where applicable, 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., shall be interpreted broadly. For example, they may refer to a fixed connection, a detachable connection, or an integral part; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; they may refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0046] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0047] It should be noted that, if an element is described as "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is described as "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0048] To improve the heat dissipation of a single battery cell, this application proposes a single battery cell and a battery.

[0049] Please refer to Figure 1 In this embodiment, the battery 1000 includes a battery cell 100. The battery cell 100 is the smallest unit in the battery 1000 where the electrochemical reaction takes place, and can be a secondary battery 1000 or a primary battery 1000. The battery cell 100 can be a lithium-ion battery 1000, a sodium-ion battery 1000, or a magnesium-ion battery 1000, but is not limited to these. The battery cell 100 can be cylindrical, flat, cuboid, or other shapes.

[0050] In some embodiments, the battery cell 100 includes a housing 60, an end cap 10, and an electrode assembly 20. The housing 60 and the end cap 10 together form an internal space for accommodating the electrode assembly 20. Specifically, the housing 60 may have a receiving cavity formed therein, with at least one end open. The end cap 10 closes to the open end of the housing 60 to seal the receiving cavity, and the electrode assembly 20 is mounted within the receiving cavity. The housing 60 may be, but is not limited to, a metal housing 60, such as an aluminum housing, a steel housing, etc.

[0051] The electrode assembly 20 typically includes a positive electrode, a negative electrode, and a separator separating the positive and negative electrodes. An electrolyte can be injected into the battery cell 100, wetting the interior of the electrode assembly 20 and providing ion migration pathways for electrochemical reactions and conductivity. The electrode assembly 20 can be in the form of a wound type, a stacked type, etc. One or more electrode assemblies 20 can be installed within the battery cell 100.

[0052] Continue to refer to Figure 1 and combined Figure 2 The battery 1000 in this embodiment further includes a liquid cooling plate 200, a thermally conductive layer 300, and an electrical connector 400. The thermally conductive layer 300 is thermally connected between the end cap 10 of the battery cell 100 and the liquid cooling plate 200. The electrical connector 400 is electrically connected to the terminal post 11 of the battery cell 100. The thermally conductive layer 300 covers the electrical connector 400.

[0053] The liquid cooling plate 200 is typically a flat plate. Channels are machined within the liquid cooling plate 200 for the flow of the cooling medium. In one embodiment, the battery 1000 includes at least one cell group, each cell group comprising multiple battery cells 100 arranged side-by-side, and a thermally conductive layer 300 connects the cell group and the liquid cooling plate 200, with one liquid cooling plate 200 dissipating heat from the multiple battery cells 100. In one embodiment, the thermally conductive layer 300 is a thermally conductive pad sandwiched between the liquid cooling plate 200 and the cell group. In another embodiment, the thermally conductive layer 300 is a thermally conductive adhesive, which is poured into the space between the liquid cooling plate 200 and the cell group, and forms the thermally conductive layer 300 after curing.

[0054] The electrical connector 400 is conductive and can be a metal component, such as aluminum foil. The electrical connector 400 can be welded to the terminal 11. In one embodiment, each electrical connector 400 connects to the terminal 11 of the same polarity of adjacent battery cells 100, achieving parallel connection of the battery cells 100. In another embodiment, each electrical connector 400 connects to the terminal 11 of different polarities of two adjacent battery cells 100, achieving series connection of the battery cells 100. Furthermore, the battery 1000 also includes a signal acquisition component connected to the electrical connector 400, which acquires the temperature / voltage of the battery cells 100.

[0055] The thermally conductive layer 300 surrounds the electrical connector 400. If the thermally conductive layer 300 is a thermally conductive pad, pre-drilled holes can be made in the thermally conductive pad to accommodate and surround the electrical connector 400. If the thermally conductive layer 300 is a thermally conductive adhesive, the thermally conductive adhesive is filled around the electrical connector 400 during potting to surround the electrical connector 400. The heat generated by the battery cell 100 can be transferred to the liquid cooling plate 200 not only through the end cap 10 and the thermally conductive layer 300, but also through the terminal post 11, the electrical connector 400, and the thermally conductive layer 300.

[0056] Reference Figure 3 In one embodiment, the electrical connector 400 is provided with fins 401. Specifically, multiple fins 401 may be provided on the electrical connector 400, and the fins 401 may be arranged in parallel or staggered. The provision of fins 401 increases the heat conduction area between the electrical connector 400 and the heat-conducting layer 300, thereby improving the heat dissipation efficiency of the electrical connector 400.

[0057] Reference Figure 2In one embodiment, a pressure relief structure 12 is provided on the end cap 10 of the battery cell 100, and an exhaust channel 301 is provided on the heat-conducting layer 300. The pressure relief structure 12 is located in the exhaust channel 301 so that when the pressure relief structure 12 is opened, hot gas inside the battery cell 100 can be allowed to flow out through the exhaust channel 301, thus preventing the battery cell 100 from exploding. The pressure relief structure 12 may be a thinning groove formed on the end cap 10 or a pressure relief valve provided at the pressure relief port of the end cap 10, which can be opened when the pressure difference between the inside and outside of the battery cell 100 exceeds a threshold.

[0058] In one embodiment, the battery 1000 further includes a baffle strip (not shown), which is located between the liquid cooling plate 200 and the plurality of battery cells 100, and together encloses a potting space, with the thermally conductive layer 300 located in the potting space. In this case, the thermally conductive layer 300 is formed by thermally conductive adhesive filled in the potting space. The baffle strip may be bonded to the liquid cooling plate 200 and / or the cell assembly. Alternatively, a baffle strip may be provided along the edge of each cell assembly. When a pressure relief structure 12 is provided on the cell assembly end cap 10, a baffle strip may be arranged corresponding to the pressure relief structure 12 to prevent the thermally conductive adhesive from blocking the pressure relief structure 12, and to form a channel for the pressure relief structure 12 to release air. The specific arrangement of the baffle strip is not specifically limited in this embodiment.

[0059] The battery cell 100 of the present application embodiment is described in detail below.

[0060] Please refer to Figure 4 , Figure 5 and Figure 6 The battery cell 100 proposed in this application includes an end cap 10, an electrode assembly 20, an adapter 30, and a plastic part 40. An electrode post 11 is disposed on the end cap 10. The electrode assembly 20 includes a heat dissipation surface 21 spaced relative to the end cap 10 along the thickness direction Z, and a tab 22 protruding from the heat dissipation surface 21. The adapter 30 and the plastic part 40 are arranged between the end cap 10 and the heat dissipation surface 21. The adapter 30 electrically connects the tab 22 and the electrode post 11, and the plastic part 40 thermally connects the end cap 10, the heat dissipation surface 21, and the adapter 30.

[0061] The end cap 10 is typically made of metal, which offers advantages such as high strength and good thermal conductivity. The end cap 10 can be square, round, or other shapes. The battery cell 100 is typically also enclosed in a housing 60, with one or both ends of the housing 60 open. The end cap 10 is positioned at the open end of the housing 60. The adapter 30 is conductive and can be, but is not limited to, made of metal. The adapter 30 can be a sheet-like structure. In some applications, the thickness direction Z of the end cap 10 corresponds to the height direction of the battery cell 100. The electrode assembly 20 has one or both end faces along this thickness direction Z that form a heat dissipation surface 21, with tabs 22 protruding from the heat dissipation surface 21. The tabs 22 include a positive tab 22 and a negative tab 22, and the terminals 11 include a positive terminal 11 and a negative terminal 11. The positive tab 22 and the positive terminal 11 are electrically connected via an adapter 30, and the negative tab 22 and the negative terminal 11 are electrically connected via another adapter 30. The adapter 30 can be connected to the tab 22 and the electrode sheet by, but is not limited to, welding, bonding, or pressing.

[0062] The plastic component 40 is made of plastic, which has good insulation and thermal conductivity. In this embodiment, the plastic component 40 is thermally connected to the end cap 10, the heat dissipation surface 21, and the adapter 30. The heat generated by the electrode assembly 20 can be transferred to the liquid cooling plate 200 not only through the tab 22, adapter 30, electrode post 11, electrical connector 400, and thermally conductive layer 300, but also through the heat dissipation surface 21, plastic component 40, end cap 10, and thermally conductive layer 300, or through the adapter 30, plastic component 40, end cap 10, and thermally conductive layer 300. Thus, the internal heat dissipation path of the electrode assembly 20 is no longer singular, and the heat dissipation effect of the battery cell 100 is significantly improved.

[0063] In some embodiments, the thermal conductivity of the plastic component 40 is 0.2–1 W / (m·K). Specifically, the plastic component 40 can be made of materials such as silicone rubber, high-density polyethylene, polycarbonate, or polyoxymethylene. In practical applications, the thermal conductivity of the plastic component 40 can be improved by adding thermally conductive fillers (metal fibers, glass fibers, etc.). When the thermal conductivity of the plastic component 40 is within this range, the plastic component 40 maintains good insulation while exhibiting good thermal conductivity, which can significantly improve the heat dissipation effect of the electrode assembly 20.

[0064] In some embodiments, the plastic part 40 includes a thermally conductive portion (not shown) and a phase change portion (not shown), with the phase change portion enclosed within the thermally conductive portion. The phase change portion has a solid-liquid phase change temperature of 50–70°C. The thermally conductive portion includes a thermally conductive connecting end cap 10, a heat dissipation surface 21, and an adapter 30. Specifically, the thermally conductive portion can be made of a material with a thermal conductivity in the range of 0.2–1 W / (m·K). The phase change portion can be made of a phase change material with a solid-liquid phase change temperature of 50–70°C, such as paraffin hydrocarbons or polyethylene glycol. In this case, by providing a phase change portion within the plastic part 40, when the temperature of the battery cell 100 reaches the phase change temperature, the phase change portion absorbs ambient heat, preventing the battery cell 100 from overheating and affecting its performance.

[0065] Combination Figures 6 to 10 Understandably, in some embodiments, the plastic part 40 includes a first contact portion 41 and a second contact portion 42 connected along the aforementioned thickness direction Z. The first contact portion 41 is in surface contact with the end cap 10, and the second contact portion 42 is in surface contact with the heat dissipation surface 21. The adapter 30 is disposed between the first contact portion 41 and the second contact portion 42, and is in surface contact with at least one of the first contact portion 41 and the second contact portion 42.

[0066] The first contact portion 41 and the second contact portion 42 are integrally connected. The first contact portion 41 is located on top and contacts the inner large surface of the end face. The second contact portion 42 is located on the bottom and contacts a portion of the heat dissipation surface 21 while avoiding the tab 22. The adapter 30 is arranged between the first adapter portion and the second adapter portion and is connected to the first contact portion 41 and / or the second contact portion 42. In this way, the heat from the heat dissipation surface 21 can be directly transferred to the end cover 10 via the second contact portion 42 and the first contact portion 41, or it can be transferred to the end cover 10 via the tab 22, the adapter 30, the first contact portion 41 and / or the second contact portion 42.

[0067] In one specific embodiment, the end cap 10 is square in shape. The first contact portion 41 extends from one end of the end cap 10 to the other end along the length Y direction of the end cap 10. In this way, the first contact portion 41 has a large contact area with the end face, resulting in high heat conduction efficiency.

[0068] At this time, the first contact part 41 contacts the large surface of the end cover 10, and the second contact part 42 contacts the large surface of the heat dissipation surface 21. The adapter 30 is thermally connected to the end cover 10 through the first contact part 41 and / or the second contact part 42. The plastic part 40 has a high heat conduction efficiency, and the battery cell 100 has a good heat dissipation effect.

[0069] Combination Figures 6 to 10In a specific embodiment, the first contact portion 41 includes a first contact area 41a that is spaced apart from the second contact portion 42 along the thickness direction Z. A receiving space k1 is formed between the first contact area 41a and the second contact portion 42. A first clearance hole a1 communicating with the receiving space k1 is provided on the first contact area 41a. The pole post 11 passes through the first clearance hole a1 and extends into the receiving space k1. The adapter 30 is located in the receiving space k1 and is electrically connected to the pole post 11.

[0070] Optionally, the receiving space k1 is a receiving hole coaxial with the first clearance hole a1, the adapter 30 is located inside the receiving hole, and the pole post 11 extends into the receiving hole through the first clearance hole a1 and is electrically connected to the adapter 30. In this case, a hole for clearance of the pole tab 22 can be provided on the second contact portion 42, so that the pole tab 22 can also extend into the receiving hole and be electrically connected to the adapter 30, that is, the projections of the pole post 11, the adapter 30 and the pole tab 22 along the thickness direction Z intersect.

[0071] Alternatively, the accommodating space k1 is an accommodating groove communicating with the first clearance hole a1. When the end cap 10 is square, the accommodating groove is open on one side along the length direction Y of the end cap 10. Part of the adapter 30 extends into the accommodating groove through the open side and is electrically connected to the pole post 11, while the remaining part is located outside the accommodating groove and is electrically connected to the tab 22. In this case, the projections of the pole post 11 and the tab 22 along the thickness direction Z are offset.

[0072] Regardless of the structure of the accommodating space k1, the adapter 30 is located in the accommodating space k1 and connected to the pole post 11, and it forms contact with the inner wall surface of the accommodating space k1 with the second contact part 42, so that the heat on the adapter 30 can be transferred outward not only through the pole post 11, but also through the second contact part 42, resulting in high heat conduction efficiency.

[0073] Combination Figures 6 to 10 In the embodiment, the first contact area 41a is provided with a protruding edge a2 on the side opposite to the second contact portion 42. The protruding edge a2 surrounds the first clearance hole a1 and is thermally connected to the end cap 10 and the pole post 11 along the thickness direction Z.

[0074] The end cap 10 is usually made of metal. The protruding edge a2 is placed between the end cap 10 and the pole post 11. This not only enables heat conduction between the pole post 11 and the end cap 10 and improves heat dissipation efficiency by utilizing the larger area of ​​the end cap 10, but also insulates the pole post 11 and the end cap 10, reducing the risk of leakage between them.

[0075] Specifically, in combination Figure 6Understandably, the pole post 11 includes an end head 11a located in the accommodating space k1. The end head 11a is connected to the adapter 30, and the protruding edge a2 is pressed on the side of the end head 11a away from the adapter 30, so that the pole post 11, the adapter 30, and the second contact portion 42 are tightly fitted together.

[0076] In one embodiment, combined with Figure 6 It is understood that the battery cell 100 also includes a sealing ring 50, and the terminal post 11 is mounted on the top cover through the sealing ring 50. On the one hand, the sealing ring 50 helps to tightly mount the terminal post 11 to the top cover and insulate the terminal post 11 and the end cover 10. On the other hand, the sealing ring 50 can prevent the leakage of liquid inside the battery cell 100 or the entry of external moisture into the battery cell 100.

[0077] In some embodiments, combined with Figures 6 to 10 It is understood that the first contact portion 41 also includes a second contact portion 41b adjacent to and connected to the first contact area 41a. The projection of the second contact area 41b and the second contact portion 42 along the thickness direction Z is offset. The second contact area 41b and the heat dissipation surface 21 form a clearance space k2, and the electrode tab 22 is located in the clearance space k2. Part of the adapter 30 is located in the accommodating space k1 and connected to the electrode post 11, and the remaining part is located in the clearance space k2 and connected to the electrode tab 22. The remaining part is in contact with the surface of the second contact area 41b.

[0078] Specifically, the accommodating space k1 is the accommodating groove structure described above. The accommodating groove is open to the clearance space k2. Part of the adapter 30 extends into the accommodating groove through the open side, while the other part is located in the clearance space k2 and contacts the electrode tab 22. The adapter 30 is located between the electrode post 11 and the second contact portion 42 along the thickness direction Z. When assembling the battery cell 100, it is only necessary to insert the adapter 30 into the accommodating groove, making the installation of the adapter 30 convenient.

[0079] At this time, the structure of the plastic part 40 is adapted to the situation where the pole post 11 and the tab 22 are staggered, and the part of the adapter 30 located in the clearance space k2 is in contact with the surface of the first contact part 41, which further increases the heat transfer area of ​​the adapter 30 and the plastic part 40, and further improves the heat dissipation effect of the battery cell 100.

[0080] In some embodiments, refer to Figure 8 and Figure 10 The first contact portion 41 has a recessed groove a3 at one end facing the second contact portion 42. The accommodating space k1 includes a portion of the groove a3, and the clearance space k2 includes another portion of the groove a3.

[0081] Specifically, when the end cap 10 is square, the groove a3 extends in a strip shape along the length Y of the end cap 10. This makes full use of the space occupied by the first contact portion 41 to accommodate the adapter 30 and the tab 22, reduces the gap between the end cap 10 and the heat dissipation surface 21, and improves the space utilization of the battery cell 100.

[0082] In some embodiments, combined with Figures 7 to 10 It is understood that the battery cell 100 also includes a pressure relief structure 12 disposed on the end cap 10, and the second contact area 41b is provided with a vent hole h, with the pressure relief structure 12 and the vent hole h being disposed opposite each other. The vent hole h is used to avoid the pressure relief structure 12 so that the internal air pressure of the battery cell 100 can act on the pressure relief structure 12, allowing it to open smoothly.

[0083] In some embodiments, combined with Figures 6 to 10 It is understood that the plastic part 40 also includes a support portion 41c, which is thermally supported between the second contact area 41b and the heat dissipation surface 21, and the support portion 41c is arranged around the vent hole h.

[0084] To reduce the gap between the heat dissipation surface 21 and the end cap 10 and improve the internal space utilization of the battery cell 100, the thickness of the first contact portion 41 is typically designed to be small. Considering that the first contact portion 41 makes large-area contact with the end cap 10, especially when the end cap 10 is square, the first contact portion 41 has a large dimension in the length direction Y of the end cap 10. A support portion 41c is provided below the second contact area 41b to support the first contact portion 41, which allows the first contact portion 41 to effectively fit the end cap 10, improving the heat transfer effect.

[0085] The support part 41c and the second contact area 41b are usually connected as one piece. The support part 41c also directly connects the heat dissipation surface 21 and the second contact area 41b in a thermally conductive manner, which increases the heat transfer area between the plastic part 40 and the heat dissipation surface 21 and improves the heat dissipation efficiency of the electrode assembly 20.

[0086] The vent h is used to avoid the pressure relief structure 12 on the end cap 10, preventing the plastic part 40 from obstructing the discharge of hot gas from the pressure relief structure 12 to the battery cell 100. The support part 41c is arranged around the vent h, indicating that the support part 41c is arranged correspondingly to the pressure relief structure 12. When the pressure relief structure 12 is depressurized, the high-pressure gas can easily vibrate the plastic part 40, preventing it from effectively contacting the end cap 10. The setting of the support part 41c can improve the strength of the plastic part 40 at the corresponding position of the pressure relief structure 12, making the plastic part 40 reliable in use.

[0087] In one specific embodiment, combined with Figures 7 to 10Understandably, the support part 41c includes an enclosing area c1 and a mesh area c2. The enclosing area c1 is thermally supported between the second contact area 41b and the heat dissipation surface 21. The mesh area c2 is in contact with the heat dissipation surface 21. The enclosing area c1 is set around the edge of the mesh area c2 and surrounds the air vent h.

[0088] At this time, the vent h and the mesh of the grid area c2 are connected, facilitating the flow of generated gas in the electrode assembly 20 through the mesh and vent h to the pressure relief structure 12. The grid area c2 increases the heat conduction area between the support part 41c and the heat dissipation surface 21, improving the heat transfer efficiency between the heat dissipation surface 21 and the plastic part 40. The enclosure area c1 is used to support the second contact part 42 and the heat dissipation surface 21.

[0089] Understandably, the enclosed area c1 encloses part of the air passage h, and the second contact area 41b opens another part of the air passage h.

[0090] Furthermore, combined Figures 7 to 10 Understandably, a second clearance hole a4 is provided on the second contact area 41b, and an injection hole is provided on the end cap 10. The injection hole and the second clearance hole a4 are arranged opposite to each other along the thickness direction Z. The second clearance hole a4 is connected to the clearance space k2 so that electrolyte can be injected into the injection hole.

[0091] Furthermore, the end cap 10 is square in shape, and the battery cell 100 includes multiple electrode assemblies 20 arranged side by side along the width direction X of the end cap 10. Among all the electrode assemblies 20, the tabs 22 with the same polarity are connected to the same adapter 30, which reduces the number of adapters 30, simplifies the assembly process of the battery cell 100, and improves the assembly efficiency.

[0092] In one embodiment of this application, the end cap 10 is provided with two pole posts 11, and the plastic part 40 includes a first contact portion 41 and a second contact portion 42. The first contact portion 41 includes two first contact areas 41a located at both ends and a second contact area 41b located between the two first contact areas 41a. Both the first contact areas 41a and the second contact area 41b are in contact with the surface of the end cap 10. The two second contact portions 42 are connected one-to-one with the two first contact areas 41a and are both in contact with the heat dissipation surface 21. A receiving space k1 is formed between each first contact area 41a and the second contact portion 42, and a clearance space k2 is formed between the second contact area 41b and the heat dissipation surface 21. Two tabs 22 protrude from the heat dissipation surface 21 and are located in the clearance space k2. A connector 30 is provided in each receiving space k1, and a portion of the connector 30 extends out of the receiving space k1 and connects to the tab 22. The portion of the connector 30 connected to the tab 22 contacts the surface of the second contact area 41b, and the portion of the connector 30 connected to the pole post 11 contacts the surface of the second contact portion 42. The plastic part 40 also includes a support portion 41c located in the clearance space k2. The support portion 41c is located between the two tabs 22 and is supported between the second contact area 41b and the heat dissipation surface 21.

[0093] The battery in this application embodiment includes all the beneficial effects of the above embodiments.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery cell, characterized in that, include: End cap (10), on which a pole post (11) is provided; The electrode assembly (20) includes a heat dissipation surface (21) spaced apart from the end cap (10) along the thickness direction (Z) of the end cap (10), and an electrode tab (22) protruding from the heat dissipation surface (21); The adapter (30) and the plastic part (40) are arranged between the end cap (10) and the heat dissipation surface (21); the adapter (30) is electrically connected to the tab (22) and the pole (11), and the plastic part (40) is thermally connected to the end cap (10), the heat dissipation surface (21) and the adapter (30).

2. The battery cell according to claim 1, characterized in that, The thermal conductivity of the plastic part (40) is 0.2–1 W / (m·K); and / or, The plastic part (40) includes a heat-conducting part and a phase change part. The phase change part is wrapped inside the heat-conducting part. The solid-liquid phase change temperature of the phase change part is 50-70°C. The heat-conducting part thermally connects the end cap (10), the heat dissipation surface (21), and the adapter (30).

3. The battery cell according to claim 1, characterized in that, The plastic part (40) includes a first contact portion (41) and a second contact portion (42) connected along the thickness direction (Z). The first contact portion (41) contacts the end cap (10) surface, and the second contact portion (42) contacts the heat dissipation surface (21) surface. The adapter (30) is disposed between the first contact portion (41) and the second contact portion (42), and is in surface contact with at least one of the first contact portion (41) and the second contact portion (42).

4. The battery cell according to claim 3, characterized in that, The first contact portion (41) includes a first contact area (41a) that is spaced apart from the second contact portion (42) along the thickness direction (Z). An accommodating space (k1) is formed between the first contact area (41a) and the second contact portion (42). A first clearance hole (a1) communicating with the accommodating space (k1) is provided on the first contact area (41a). The pole post (11) passes through the first clearance hole (a1) and extends to the accommodating space (k1). The adapter (30) is located in the accommodating space (k1) and is electrically connected to the pole post (11). The adapter (30) located in the accommodating space (k1) is in surface contact with the second contact portion (42).

5. The battery cell according to claim 4, characterized in that, The first contact area (41a) is provided with a protruding edge (a2) on the side opposite to the second contact portion (42). The protruding edge (a2) surrounds the first clearance hole (a1) and thermally connects the end cap (10) and the pole post (11) along the thickness direction (Z).

6. The battery cell according to claim 4, characterized in that, The first contact portion (41) further includes a second contact portion (41b) adjacent to and connected to the first contact area (41a). The second contact portion (41b) and the second contact portion (42) are offset from each other along the thickness direction (Z). The second contact portion (41b) and the heat dissipation surface (21) are spaced apart to form a clearance space (k2). The tab (22) is located in the clearance space (k2). A portion of the adapter (30) is located in the accommodating space (k1) and connected to the pole post (11), while the remaining portion is located in the clearance space (k2) and connected to the tab (22). The remaining portion is in contact with the surface of the second contact area (41b).

7. The battery cell according to claim 6, characterized in that, The first contact portion (41) has a recessed groove (a3) ​​at one end facing the second contact portion (42), the accommodating space (k1) includes a portion of the groove (a3), and the clearance space (k2) includes another portion of the groove (a3); and / or, The battery cell also includes a pressure relief structure (12) disposed on the end cap (10), and the plastic part (40) includes an air vent (h) penetrating the second contact area (41b), and the pressure relief structure (12) is disposed opposite to the air vent (h); The plastic part (40) also includes a support portion (41c), which is thermally supported between the second contact area (41b) and the heat dissipation surface (21), and the support portion (41c) is arranged around the vent (h).

8. The battery cell according to claim 7, characterized in that, The support portion (41c) includes an enclosure area (c1) and a mesh area (c2). The enclosure area (c1) is thermally supported between the second contact area (41b) and the heat dissipation surface (21). The mesh area (c2) is in contact with the heat dissipation surface (21). The enclosure area (c1) is disposed around the edge of the mesh area (c2) and surrounds the vent (h).

9. A battery, characterized in that, include: The battery cell as described in any one of claims 1 to 8; Liquid cooling plate (200); A thermally conductive layer (300) is thermally connected between the end cap (10) of the battery cell and the liquid cooling plate (200); and An electrical connector (400) is electrically connected to the terminal post (11) of the battery cell, and the thermally conductive layer (300) wraps around the electrical connector (400).

10. The battery according to claim 9, characterized in that, The electrical connector (400) is provided with fins (401); and / or, The end cap (10) is provided with a pressure relief structure (12), the heat-conducting layer (300) is provided with an exhaust channel (301), and the pressure relief structure (12) is located in the exhaust channel (301); and / or, The battery includes a sealant strip located between the liquid cooling plate (200) and multiple battery cells, which together enclose a potting space, and the thermally conductive layer (300) is located in the potting space.

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