Battery cell and battery pack

Abstract

The invention provides a battery cell and a battery pack, relates to the technical field of batteries, and aims to improve the infiltration effect of a pole piece in an electrolyte. The battery cell comprises a shell, wherein an accommodating cavity is formed in the shell; the electrode assembly is positioned in the accommodating cavity; the insulating layer is located in the containing cavity, the insulating layer is arranged between the electrode assembly and the inner wall of the shell so that the electrode assembly can be insulated from the shell, and the insulating layer and the electrode assembly are arranged in a spaced mode. According to the battery cell and the battery pack provided by the invention, the insulating layer and the electrode assembly are arranged at an interval, so that when the electrolyte is injected into the shell, the electrolyte can be filled in the interval between the insulating layer and the electrode assembly, and the electrolyte is in direct contact with a pole piece in the electrode assembly, so that the infiltration effect of the pole piece in the electrolyte is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell and a battery pack. Background Art

[0002] The battery pack is the power system of the battery pack of electric vehicles, electric trains, etc. The battery cell usually includes a shell and an electrode assembly in the shell. The electrode assembly includes a positive electrode sheet and a negative electrode sheet. After the electrolyte is injected into the shell, the positive electrode sheet and the negative electrode sheet are immersed in the electrolyte. The ions in the electrolyte move between the positive and negative electrodes to make the battery cell conductive.

[0003] However, the electrode has poor wetting effect in the electrolyte. Summary of the invention

[0004] The present application provides a battery cell and a battery pack for improving the wetting effect of a pole piece in an electrolyte.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] One aspect of the present application provides a battery cell, comprising:

[0007] A housing having a receiving cavity therein;

[0008] an electrode assembly, wherein the electrode assembly is located in the accommodating cavity;

[0009] An insulating layer is located in the accommodating cavity, and the insulating layer is arranged between the electrode assembly and the inner wall of the shell to insulate the electrode assembly from the shell. The insulating layer is spaced apart from the electrode assembly.

[0010] In a possible implementation, the insulating layer is adhered to the side wall and the bottom wall of the accommodating cavity by thermoplasticization, evaporation or spraying.

[0011] In a possible implementation manner, the top of the insulating layer is located below the top of the accommodating cavity.

[0012] In a possible implementation, the thickness of the insulating layer is 0.01 mm-1 mm.

[0013] In a possible implementation, one end of the housing has an opening, and the opening is communicated with the accommodating cavity;

[0014] The battery cell further includes a cover plate assembly, which is installed at the opening and closes the opening.

[0015] In a possible implementation, the cover plate assembly includes a base plate, an insulating member, a pressing plate and a pole;

[0016] The substrate is installed at the opening, and a first through hole is formed on the substrate;

[0017] The insulating member is arranged on the substrate, and the insulating member comprises a first insulating portion, the material of the first insulating portion is a high temperature resistant insulating material, and a second through hole is opened on the first insulating portion;

[0018] The pressing plate is arranged on the insulating member, and a third through hole is formed on the pressing plate;

[0019] The pole includes a connected column and a bottom plate, the bottom plate is electrically connected to the electrode assembly, the bottom plate abuts against the bottom of the substrate, and the pole passes through the first through hole, the second through hole and the third through hole in sequence and then is connected to the pressure plate.

[0020] In a possible implementation manner, the material of the first insulating part includes ceramic, PEEK or PTFE.

[0021] In a possible implementation, a rectangular groove is formed on the insulating member, the pressing plate is pressed on the bottom of the rectangular groove, four protrusions are provided on the bottom of the rectangular groove, and the four protrusions are respectively located at four corners of the rectangular groove;

[0022] The bottom of the pressing plate is provided with four avoidance grooves corresponding to the protruding parts.

[0023] In a possible implementation manner, an insulating sealing ring is sandwiched between the pole and the substrate.

[0024] Another aspect of the present application provides a battery pack, which includes the battery cell in any one of the above items.

[0025] The battery cell and battery pack provided in this application have the following beneficial effects:

[0026] The battery cell includes a shell, an electrode assembly and an insulating layer. The shell has a receiving cavity so that the electrode assembly can be installed in the receiving cavity in the shell. The insulating layer is located in the receiving cavity and is arranged between the electrode assembly and the inner wall of the shell so that the electrode assembly and the shell are insulated.

[0027] Compared with the related art, the battery cell and battery pack provided in the present application are arranged through the spacing between the insulating layer and the electrode assembly, so that when the electrolyte is injected into the shell, the electrolyte can be filled in the gap between the insulating layer and the electrode assembly, so that the electrolyte directly contacts the electrode plate in the electrode assembly, thereby improving the wetting effect of the electrode plate in the electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 A schematic diagram of the explosion structure of a battery cell provided in an embodiment of the present application;

[0030] Figure 2 for Figure 1 A schematic diagram of the structure of the middle shell;

[0031] Figure 3 for Figure 1 Schematic diagram of the structure of the insulating part.

[0032] Description of reference numerals:

[0033] 10. Shell;

[0034] 101. accommodating cavity; 102. opening;

[0035] 20. Electrode assembly;

[0036] 30. Insulation layer;

[0037] 40. Cover plate assembly;

[0038] 41, substrate; 411, first through hole; 42, insulating member; 42a, first insulating portion;

[0039] 421, second through hole; 422, rectangular groove; 423, raised portion; 43, pressing plate;

[0040] 431, third through hole; 432, avoidance groove; 44, pole; 44a, column;

[0041] 44b, bottom plate;

[0042] 50. Insulating sealing ring. DETAILED DESCRIPTION

[0043] The battery cell has a technical problem of poor electrode wetting in the electrolyte. The reason for this problem is that the electrode assembly usually includes a winding core formed by winding the electrode or a stacked core formed by stacking the electrode, and the outer periphery of the winding core or the stacked core is coated with an insulating layer to insulate the electrode from the shell. However, when the electrolyte is injected into the shell, there is an insulating layer between the electrolyte and the electrode, so that the electrolyte needs to pass through the insulating layer before wetting the electrode, resulting in poor electrode wetting in the electrolyte.

[0044] In response to the above technical problems, the present application provides a battery cell and a battery pack, which, by setting the insulation layer and the electrode assembly at intervals, allows the electrolyte to be filled in the gap between the insulation layer and the electrode assembly when the electrolyte is injected into the shell, so that the electrolyte directly contacts the electrode sheet in the electrode assembly, thereby improving the wetting effect of the electrode sheet in the electrolyte.

[0045] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments 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 ordinary technicians in this field without creative work belong to the scope of protection of this application.

[0046] like Figure 1 As shown, an embodiment of the present application provides a battery cell, which includes a shell 10, an electrode assembly 20 and an insulating layer 30. The shell 10 is the outer shell of the battery cell, and the shell 10 can protect the electrode assembly 20 in the shell 10. The shell 10 has a receiving cavity 101, and the shell 10 can be a cylindrical hollow shell, a nearly cylindrical hollow shell, a rectangular hollow shell, or a nearly rectangular hollow shell.

[0047] The electrode assembly 20 is located in the accommodating cavity 101. The electrode assembly 20 can be a wound electrode assembly or a laminated electrode assembly, wherein the wound electrode assembly includes a cylindrical or approximately cylindrical winding core formed by winding the positive electrode sheet, the negative electrode sheet, and the separator between the positive electrode sheet and the negative electrode sheet. The laminated electrode assembly is a laminated core formed by stacking the positive electrode sheet, the negative electrode sheet, and the separator between the positive electrode sheet and the negative electrode sheet together.

[0048] The insulating layer 30 is located in the accommodating cavity 101 . The insulating layer 30 is made of an insulating material. The material of the insulating layer 30 may be polypropylene (PP), polyethylene glycol terephthalate (PET), ceramic, etc.

[0049] The insulating layer 30 is disposed between the electrode assembly 20 and the inner wall of the shell 10 to separate the electrode assembly 20 and the shell 10, thereby insulating the electrode assembly 20 and the shell 10. The insulating layer 30 is spaced apart from the electrode assembly 20, and there is a gap between the insulating layer 30 and the electrode assembly 20, thereby preventing the insulating layer 30 from covering the electrode assembly 20.

[0050] For example, the insulating layer 30 may include a first insulating layer and a second insulating layer, the first insulating layer may be disposed at the bottom of the housing 10, and the electrode assembly 20 may be disposed on the first insulating layer. The second insulating layer may be an annular structure, which is mounted on the first insulating layer, the side wall of the accommodating cavity 101 is located on the outside of the second insulating layer, the electrode assembly 20 is located on the inside of the second insulating layer, and there is a spacing space between the electrode assembly 20 and the second insulating layer. When the electrolyte is injected into the housing 10, the electrolyte can be filled in the spacing space between the second insulating layer and the electrode assembly 20, so that the electrolyte directly contacts the positive electrode sheet and the negative electrode sheet in the electrode assembly 20, thereby improving the infiltration effect of the electrode sheet in the electrolyte.

[0051] In the battery cell and battery pack provided in the present application, the battery cell includes a shell 10, an electrode assembly 20 and an insulating layer 30. The shell 10 has a receiving cavity 101, so that the electrode assembly 20 can be installed in the receiving cavity 101 in the shell 10. The insulating layer 30 is located in the receiving cavity 101, and the insulating layer 30 is arranged between the electrode assembly 20 and the inner wall of the shell 10, so that the electrode assembly 20 and the shell 10 are insulated. The insulating layer 30 and the electrode assembly 20 are arranged at intervals, so that when the electrolyte is injected into the shell 10, the electrolyte can be filled in the interval between the insulating layer 30 and the electrode assembly 20, so that the electrolyte is directly in contact with the pole piece in the electrode assembly 20, thereby improving the infiltration effect of the pole piece in the electrolyte.

[0052] In some embodiments, Figure 2 As shown, the insulating layer 30 is attached to the side wall and the bottom wall of the accommodating cavity 101 by thermoplasticization, evaporation or spraying. Thermoplasticization is to utilize the plasticity of thermoplastic plastic after being softened by heating, and to deform it by applying pressure and attach it to the side wall and the bottom wall of the accommodating cavity 101, and finally cool and shape it into the insulating layer 30.

[0053] Evaporation is also called vacuum evaporation or vacuum coating. It is a process method in which a material is heated to a vaporized state in a vacuum environment and deposited onto the surface of a substrate to obtain a thin film material, so that the insulating layer 30 is attached to the side walls and bottom wall of the accommodating cavity 101 .

[0054] Spraying is to use a spray gun or a nozzle or other spraying equipment to atomize the paint into tiny particles, and spray these particles to the side walls and bottom wall of the receiving cavity 101 through air pressure or centrifugal force. During the spraying process, the paint particles collide with and adhere to the side walls and bottom wall of the receiving cavity 101, forming a uniform coating film, so that the insulating layer 30 is attached to the side walls and bottom wall of the receiving cavity 101.

[0055] In the embodiment of the present application, the insulating layer 30 is adhered to the side walls and bottom walls of the accommodating cavity 101 by thermoplasticization, evaporation or spraying, so that the insulating layer 30 and the side walls and bottom walls of the accommodating cavity 101 are firmly connected to prevent the insulating layer 30 from falling off.

[0056] In some embodiments, Figure 2 As shown, the top of the insulating layer 30 is located below the top of the accommodating cavity 101, for example, there is a gap of at least 0.1 mm between the top of the insulating layer 30 and the top of the accommodating cavity 101. This prevents the insulating layer 30 from affecting the welding of the cover assembly 40 of the battery cell to the closed shell 10, and reduces the defective rate when the cover assembly 40 and the shell 10 are welded.

[0057] In some embodiments, the thickness of the insulating layer 30 is 0.01 mm-1 mm, for example, the thickness of the insulating layer 30 may be 0.01 mm, 0.1 mm, 0.5 mm or 1 mm. In this way, it is possible to avoid the problem that the insulating layer 30 is too thick and occupies the internal space of the housing 10, thereby causing the capacity density of the battery cell to be low. In this way, it is possible to avoid the insulating layer 30 being too thin and affecting the insulation of the insulating layer 30.

[0058] In some embodiments, Figure 1 As shown, one end of the housing 10 has an opening 102 for Figure 1 As shown in the example, the opening 102 can be provided at the top of the housing 10. The opening 102 is communicated with the accommodating cavity 101, and the opening 102 can be located at one end of the accommodating cavity 101 exposed outside the housing 10. The electrode assembly 20 can be placed into the accommodating cavity 101 through the opening 102.

[0059] The battery cell further includes a cover plate assembly 40, which is used to close the accommodating cavity 101, so that the housing 10 and the cover plate assembly 40 form a closed structure, thereby protecting the electrode assembly 20 in the housing 10. The cover plate assembly 40 is installed at the opening 102 and closes the opening 102. For example, the cover plate assembly 40 is welded to the side wall of the housing 10 at the opening 102, so that the cover plate assembly 40 closes the opening 102.

[0060] Based on the above embodiments, Figure 1 As shown, the cover assembly 40 includes a substrate 41, an insulating member 42, a pressing plate 43 and a pole 44. The substrate 41 is the main structure of the cover assembly 40, and the shape of the substrate 41 matches the shape of the opening 102. For example, the opening 102 is a circular hole, and the shape of the substrate 41 is a circular plate. Or the opening 101 is a square hole, and the shape of the substrate 41 is a square plate. Thus, the substrate 41 closes the opening 102. The substrate 41 is installed at the opening 102, for example, the substrate 41 is welded to the side wall of the housing 10 at the opening 102. The substrate 41 has a first through hole 411.

[0061] Continue to refer Figure 1 , the insulating member 42 is made of an insulating material. The insulating member 42 is arranged on the substrate 41, for example, the insulating member 42 is crimped on the substrate 41, and the insulating member 42 includes a first insulating portion 42a, and the material of the first insulating portion 42a is a high temperature resistant insulating material. The first insulating portion 42a has a second through hole 421, and the axis of the second through hole 421 is the same as that of the first through hole 411. The portion of the insulating member 42 other than the first insulating portion 42a can be made of a high temperature resistant insulating material, or can be made of a non-high temperature resistant insulating material.

[0062] In some examples, the high temperature resistant insulating material may be ceramic, polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), etc. The non-high temperature resistant insulating material may be polypropylene (PP), polyphenylene sulfide (PPS), etc.

[0063] Continue to refer Figure 1 The pressing plate 43 is disposed on the insulating member 42 , and the pressing plate 43 can be crimped onto the insulating member 42 . A third through hole 431 is formed on the pressing plate 43 , and the axis of the third through hole 431 is the same as that of the second through hole 421 and the first through hole 411 .

[0064] Continue to refer Figure 1 The pole 44 includes a connected column 44a and a bottom plate 44b. The pole 44a can be arranged on the bottom plate 44b, and the column 44a and the bottom plate 44b can be an integrally formed structure. The bottom plate 44b is electrically connected to the electrode assembly 20, for example, the pole lug in the electrode assembly 20 is welded to the bottom plate 44b. The bottom plate 44b abuts against the bottom of the substrate 41, for example, the top of the bottom plate 44b abuts against the bottom of the substrate 41. The column 44a passes through the first through hole 411, the second through hole 421, and the third through hole 431 in sequence and is welded or riveted to the pressing plate 43. So that the pressing plate 43 and the insulating member 42 are installed on the substrate 41.

[0065] When the battery cell is in thermal runaway, the high temperature environment easily causes the portion of the insulating member 42 close to the column 44a, that is, the portion of the insulating member 42 close to the second through hole 421 to be damaged, thereby destroying the airtightness of the battery cell, making it easy for the high-temperature gas to overflow from around the pole 44, thereby affecting the conductivity of the pole 44 and damaging the devices near the pole 44. In the embodiment of the present application, the second through hole 421 is provided in the first insulating portion 42a, and the material of the first insulating portion 42a is a high-temperature resistant insulating material, thereby avoiding the above-mentioned problems.

[0066] In some embodiments, Figure 3As shown, a rectangular groove 422 is opened on the insulating member 42 , and the pressing plate 43 is pressed on the bottom of the rectangular groove 422 . Four protrusions 423 are arranged on the bottom of the rectangular groove 422 , and the four protrusions 423 are respectively located at the four corners of the rectangular groove 422 .

[0067] like Figure 1 As shown, the bottom of the pressing plate 43 has four avoidance grooves 432, and the shapes and positions of the four avoidance grooves 432 match the four protrusions 423, so as to prevent the pressing plate 43 and the insulating member 42 from rotating along their own axes.

[0068] In some embodiments, Figure 1 As shown, the battery cell further includes an insulating sealing ring 50, which is sandwiched between the pole 44 and the substrate 41. The inner ring of the insulating sealing ring 50 is sleeved on the column 44a, and the outer ring of the insulating sealing ring 50 abuts against the inner wall of the first through hole 411 of the substrate 41, so as to ensure the sealing and insulation between the pole 44 and the substrate 41.

[0069] The present application also provides a battery pack, which is used in electrical equipment, which may include but are not limited to mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc. Specifically, the mobile devices may be, for example, mobile phones, laptop computers, etc.; the electric vehicles may be, for example, pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc., but the embodiments of the present application are not limited thereto.

[0070] The battery pack includes a battery cell, and the specific structure and related effects of the battery cell can refer to the relevant description of the above embodiments. Since the battery pack provided in this application adopts all the technical solutions of any of the above embodiments, it has at least all the beneficial effects brought by any of the above embodiments, which will not be repeated here one by one.

[0071] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0072] It should be noted that the phrases "in specific implementation", "in some embodiments", "in this embodiment", "exemplarily" and the like mentioned in the specification indicate that the described embodiment may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing specific features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments that are explicitly or not explicitly described.

[0073] In general, terms should be understood, at least in part, by the context in which they are used. For example, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense, depending, at least in part, on the context. Similarly, terms such as "a," "an," or "the" may also be understood to convey singular usage or to convey plural usage, depending, at least in part, on the context.

[0074] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0075] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0076] It should be easily understood that “on,” “above,” and “over” in the present disclosure should be interpreted in the broadest manner, so that “on” not only means “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “above” or “over” not only includes the meaning of “above” or “over,” but also may include the meaning of “above” or “over something” with no intervening features or layers therebetween (i.e., directly on something).

[0077] In addition, spatially relative terms, such as "below," "below," "beneath," "above," "above," etc., may be used herein for ease of description to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, 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 battery cell, characterized in that: include: A housing having a receiving cavity therein; an electrode assembly, wherein the electrode assembly is located in the accommodating cavity; An insulating layer is located in the accommodating cavity, and the insulating layer is arranged between the electrode assembly and the inner wall of the shell to insulate the electrode assembly from the shell. The insulating layer is spaced apart from the electrode assembly.

2. The battery cell according to claim 1, characterized in that: The insulating layer is attached to the side wall and the bottom wall of the accommodating cavity by means of thermoplasticization, evaporation or spraying.

3. The battery cell according to claim 2, characterized in that: The top of the insulating layer is located below the top of the accommodating cavity.

4. The battery cell according to claim 1, characterized in that: The thickness of the insulating layer is 0.01 mm-1 mm.

5. The battery cell according to any one of claims 1 to 4, characterized in that: One end of the shell has an opening, and the opening is communicated with the accommodating cavity; The battery cell further includes a cover plate assembly, which is installed at the opening and closes the opening.

6. The battery cell according to claim 5, characterized in that: The cover plate assembly includes a base plate, an insulating member, a pressing plate and a pole; The substrate is installed at the opening, and a first through hole is formed on the substrate; The insulating member is arranged on the substrate, and the insulating member comprises a first insulating portion, the material of the first insulating portion is a high temperature resistant insulating material, and a second through hole is opened on the first insulating portion; The pressing plate is arranged on the insulating member, and a third through hole is formed on the pressing plate; The pole includes a connected column and a bottom plate, the bottom plate is electrically connected to the electrode assembly, the bottom plate abuts against the bottom of the substrate, and the pole passes through the first through hole, the second through hole and the third through hole in sequence and then is connected to the pressure plate.

7. The battery cell according to claim 6, characterized in that: The material of the first insulating part includes ceramic, PEEK plastic or PTFE plastic.

8. The battery cell according to claim 6, characterized in that: A rectangular groove is formed on the insulating member, the pressing plate is pressed on the bottom of the rectangular groove, four protrusions are formed on the bottom of the rectangular groove, and the four protrusions are respectively located at four corners of the rectangular groove; The bottom of the pressing plate is provided with four avoidance grooves corresponding to the protruding parts.

9. The battery cell according to claim 6, characterized in that: An insulating sealing ring is sandwiched between the pole and the substrate.

10. A battery pack, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 9.

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