Battery cell and battery pack

Abstract

The utility model provides a battery cell and battery pack, the battery cell comprises an electrode assembly, a pole and a shell, the shell is provided with an accommodating chamber, the electrode assembly is located in the accommodating chamber, one side of a bottom plate close to the accommodating chamber forms a liquid discharge channel, and a plurality of liquid discharge channels are communicated. Wherein the bottom plate is provided with a liquid injection hole, the liquid injection hole is formed in the liquid drainage channel, and the liquid injection hole is used for injecting electrolyte into the containing cavity, so that the electrolyte can flow along the liquid drainage channel to infiltrate the electrode assembly. The liquid injection holes are located in the liquid drainage channels, and the multiple liquid drainage channels communicate with one another, so that the electrolyte can freely flow, the electrolyte infiltration rate is increased, and the standing infiltration time is shortened.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery cell and a battery pack. Background Art

[0002] The battery's electrolyte is a crucial component, serving as a medium for ion conduction and maintaining charge balance within the battery. In related technologies, the electrolyte injection port is located at the top of the battery casing. However, the top of the battery casing is equipped with numerous components, including the lower plastic, retaining frame, and current collector. During the battery injection process, these components can block the electrolyte, resulting in slower electrolyte penetration and uneven distribution. Utility Model Content

[0003] The embodiments of the present utility model provide a battery cell and a battery pack, which can improve the technical problem of uneven distribution of electrolyte.

[0004] In a first aspect, an embodiment of the present invention provides a battery cell, comprising:

[0005] electrode assembly;

[0006] A shell having a housing chamber, wherein the electrode assembly is located in the housing chamber, the shell including a bottom plate for supporting the electrode assembly, the bottom plate and the electrode column being located on different sides of the shell, the bottom plate being provided with a plurality of drainage channels on a side close to the housing chamber, and the bottom plate being provided with a liquid injection hole, the liquid injection hole being in communication with the plurality of drainage channels;

[0007] The injection hole is used to inject electrolyte into the accommodating chamber so that the electrolyte can flow along the drainage channel to infiltrate the electrode assembly.

[0008] In some embodiments, the bottom plate includes a plate body and a plurality of protrusions, wherein the plurality of protrusions are spaced apart on a side of the plate body facing the electrode assembly, a drainage channel is formed between any two adjacent protrusions, and the plurality of drainage channels are connected.

[0009] The battery cell includes a plurality of first protrusion groups, each of the plurality of first protrusion groups includes a plurality of protrusions arranged along a first direction, and a first flow channel is formed between two adjacent first protrusion groups;

[0010] The battery cell includes a plurality of second protrusion groups, the plurality of second protrusion groups include a plurality of protrusions arranged along a second direction, and the first flow channel is connected to the second flow channel;

[0011] The first direction is perpendicular to the second direction.

[0012] In some embodiments, the bottom plate includes two first side edges extending along a first direction, and the first flow channel extends from one first side edge to the other first side edge; and / or;

[0013] The bottom plate includes two second side edges extending along a second direction, and the second flow channel extends from one second side edge to the other second side edge.

[0014] In some embodiments, the bottom plate includes two first sides extending along a first direction, the battery cell includes a plurality of first protrusion groups connected to one of the first sides, and a second protrusion group connected to the other first side, and the protrusions of the first protrusion group and the protrusions of the second protrusion group are alternately arranged;

[0015] The protrusions of the first protrusion group are spaced apart from the other first side and form a first flow channel, the protrusions of the second protrusion group are spaced apart from the first side and form a second flow channel, the protrusions of the first protrusion group and the adjacent protrusions of the second protrusion group are at least partially opposite and spaced apart to form a third flow channel, the first flow channel and the second flow channel are located on both sides of the drainage channel, and the first flow channel, the second flow channel and the third flow channel are interconnected to form a bent flow channel.

[0016] In some embodiments, the height of the protrusion is greater than 0 and less than or equal to 1 mm.

[0017] In some embodiments, the battery cell further includes an insulating sheet, which is attached to a side of the electrode assembly facing the bottom plate, and an area of ​​the insulating sheet projected on the bottom plate is smaller than an area of ​​the bottom plate.

[0018] In some embodiments, the insulating sheet is provided with an opening, and the opening connects the accommodating chamber and the drainage channel.

[0019] In some embodiments, the battery cell further includes sealing particles, and the sealing particles are sealed and connected to the injection hole.

[0020] In some embodiments, a countersunk hole is provided on the side of the bottom plate facing away from the electrode assembly, and the countersunk hole is connected to the injection hole. The battery cell also includes a sealing plate, which is provided in the countersunk hole, and the surface of the sealing plate is flush with the surface of the bottom plate.

[0021] In a second aspect, the present application provides a battery pack comprising the battery cell as described above.

[0022] Beneficial effects of the embodiments of the present application:

[0023] In an embodiment of the present application, a battery cell includes an electrode assembly, an electrode column, and a shell. The shell is provided with a housing chamber, and the electrode assembly is located within the housing chamber. The shell includes a bottom plate, and a plurality of drainage channels are provided on a side of the bottom plate adjacent to the housing chamber. The bottom plate is provided with an injection hole, and the injection hole is connected to the plurality of drainage channels. The injection hole is used to inject electrolyte into the housing chamber so that the electrolyte can flow along the drainage channel to infiltrate the electrode assembly. The injection hole is located within the drainage channel, and the plurality of drainage channels are interconnected, so that the electrolyte can flow freely, accelerate the electrolyte infiltration rate, and reduce the static infiltration time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 This is a schematic diagram of the structure of the battery cell provided in an embodiment of the present application;

[0026] Figure 2 is an exploded view of a battery cell provided in an embodiment of the present application;

[0027] Figure 3 yes Figure 2 The structure of the bottom plate shown Figure 1 ;

[0028] Figure 4 yes Figure 2 The structure of the bottom plate shown Figure 2 ;

[0029] Figure 5 yes Figure 4 A top view of the base plate shown;

[0030] Figure 6 yes Figure 2 The structure of the bottom plate shown Figure 3 ;

[0031] Figure 7 yes Figure 2 An enlarged schematic diagram of the local A is shown;

[0032] Figure 8 yes Figure 2 Bottom view of the base plate shown.

[0033] Reference numerals:

[0034] 100, battery cell;

[0035] 10. Electrode assembly;

[0036] 20. Housing; 21. Bottom plate; 2101. First side; 2102. Second side; 2103. Counterbore; 211. Plate; 2111. Liquid injection hole; 212. Protrusion; 2120. Liquid drainage channel; 2121. First protrusion group; 2122. Second protrusion group; 2123. First flow channel; 2124. Second flow channel; 2125. Third flow channel;

[0037] 30. Insulation sheet;

[0038] 40. Sealing rubber particles; 41. Sealing plate. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0040] The electrode assembly is formed by winding or stacking positive and negative electrode sheets, with a separator between them. The portions of the positive and negative electrode sheets containing active materials constitute the main body of the electrode assembly, while the portions of the positive and negative electrode sheets without active materials each constitute the tabs. During the battery's charge and discharge process, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current circuit. In related technologies, the electrolyte injection port is located at the top of the battery casing, resulting in a slower electrolyte infiltration efficiency during the battery injection process.

[0041] Please refer to Figure 1-Figure 3 , Figure 1 is a schematic structural diagram of a battery cell 100 provided in an embodiment of the present application. Figure 2 is an exploded view of the battery cell 100 provided in an embodiment of the present application, Figure 3 yes Figure 2 The structure of the bottom plate 21 is shown as follows Figure 1. The present application provides a battery cell 100, which includes an electrode assembly 10 and a shell 20. The shell 20 is provided with a accommodating chamber, and the electrode assembly 10 is located in the accommodating chamber. The shell 20 includes a bottom plate 21 for supporting the electrode assembly 10. The bottom plate 21 and the pole are respectively located on different sides of the shell, wherein a plurality of drainage channels 2120 are provided on a side of the bottom plate 21 close to the accommodating chamber, and the bottom plate 21 is provided with an injection hole 2111. The injection hole 2111 is provided in the drainage channel 2120. The injection hole 2111 is used to inject electrolyte into the accommodating chamber so that the electrolyte can flow along the drainage channel 2120 to infiltrate the electrode assembly 10. The injection hole 2111 is located in the drainage channel 2120 and the multiple drainage channels 2120 are interconnected, so that the electrolyte can flow freely, which accelerates the electrolyte infiltration rate and reduces the static infiltration time. Good cell wetting effect is beneficial to improving the cycle performance of bare cells and extending the service life of the battery.

[0042] In some examples, the bottom plate 21 includes a plate body 211 and a plurality of protrusions 212. The plurality of protrusions 212 are spaced apart on a side of the plate body 211 facing the electrode assembly 10. A drainage channel 2120 is formed between any two adjacent protrusions 212, and the plurality of drainage channels 2120 are interconnected. The drainage channels 2120 can be elongated grooves. The protrusions 212 are evenly spaced on the bottom plate 21, ensuring that the drainage channels 2120 between adjacent protrusions 212 are evenly spaced. The protrusions on the bottom plate 21 can increase the structural strength of the bottom plate 21 when the battery is pressed against the bottom plate 21.

[0043] It should be noted that this application uses a square battery as an example, and the shape of the battery cell 100 can also be cylindrical, flat, or other shapes. The battery cell 100 can be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery. Different types of batteries use different electrolyte materials, which will not be described in detail in this application.

[0044] Please refer to Figure 4-Figure 5 , Figure 4 yes Figure 2 The structure of the bottom plate 21 is shown as follows Figure 2 , Figure 5 yes Figure 4A top view of the bottom plate 21 is shown. In some embodiments, the battery cell 100 includes a plurality of first protrusion groups 2121, each of which includes a plurality of protrusions 212 arranged along a first direction. A first flow channel 2123 is formed between two adjacent first protrusion groups 2121. The battery cell 100 also includes a plurality of second protrusion groups 2122, each of which includes a plurality of protrusions 212 arranged along a second direction. A second flow channel 2124 is formed between two adjacent second protrusion groups 2122. The first flow channel 2123 and the second flow channel 2124 are connected, and the first direction intersects and is perpendicular to the second direction.

[0045] In some examples, the first direction is the length direction of the bottom plate 21, and the first protrusion group 2121 can be arranged in two rows. Each row of the first protrusion group 2121 includes five protrusions 212, and a drainage channel 2120 is formed between two adjacent rows of protrusions 212. The five drainage channels 2120 are connected to form a first flow channel 2123, and part of the electrolyte flows along the first direction.

[0046] In some examples, the second direction is the width direction of the bottom plate 21, and the second protrusion group 2122 can be arranged in five columns. Each column of the second protrusion group 2122 includes two protrusions 212, and a drainage channel 2120 is formed between two adjacent columns of the second protrusion group 2122. The two drainage channels 2120 form a second flow channel 2124, and part of the electrolyte flows along the second direction.

[0047] It can be understood that the first flow channel 2123 and the second flow channel 2124 form a crisscross shape. Compared with a flow channel set in only one direction, the electrolyte flows along the first flow channel 2123 and the second flow channel 2124, which allows the electrolyte to infiltrate the electrode assembly 10 from multiple directions, further increasing the infiltration efficiency.

[0048] In some embodiments, the bottom plate 21 includes two first side edges 2101 extending along a first direction, and the bottom plate 21 includes two second side edges 2102 extending along a second direction.

[0049] In some examples, the first channel 2123 extends from one first side 2101 to the other first side 2101 , and the second channel 2124 extends from one second side 2102 to the other second side 2102 .

[0050] In some examples, the first channel 2123 extends from one first side 2101 to the other first side 2101 , but the second channel 2124 does not extend; or the first channel does not extend, and the second channel 2124 extends from one second side 2102 to the other second side 2102 .

[0051] It can be understood that increasing the length of the first flow channel 2123 and the second flow channel 2124 can allow the electrolyte to flow quickly and evenly to the edge of the plate 211, thereby preventing the periphery of the electrode assembly 10 from being unable to be soaked by the electrolyte.

[0052] Please refer to Figure 6 , Figure 6 yes Figure 2 The structure of the bottom plate 21 is shown as follows Figure 3 In some embodiments, the battery cell 100 includes a plurality of first protrusion groups 2121 connected to one of the first side edges 2101 and a second protrusion group 2122 connected to another of the first side edges 2101 , and the protrusions 212 of the first protrusion group 2121 and the protrusions 212 of the second protrusion group 2122 are alternately arranged. The protrusions 212 of the first protrusion group 2121 are spaced apart from the other first side 2101 to form a first flow channel 2123, the protrusions 212 of the second protrusion group 2122 are spaced apart from the first side 2101 to form a second flow channel 2124, the protrusions 212 of the first protrusion group 2121 and the protrusions 212 of the adjacent second protrusion group 2122 are at least partially opposite to each other to form a third flow channel 2125, the first flow channel 2123 and the second flow channel 2124 are located on both sides of the third flow channel 2125, the first flow channel 2123, the second flow channel 2124 and the third flow channel 2125 are interconnected to form a bent flow channel.

[0053] Specifically, the first direction is the length direction of the bottom plate 21, and the two adjacent protrusions 212 are alternately arranged toward different sides. A drainage channel 2120 is formed between the two adjacent protrusions 212. The first flow channel 2123 is located on one side of the drainage channel 2120, and the second flow channel 2124 is located on the other side of the third flow channel 2125. The first flow channel 2123, the second flow channel 2124 and the third flow channel 2125 are interconnected to form an S-shaped flow channel.

[0054] In some embodiments, the plurality of protrusions 212 include a first protrusion group 2121 arranged opposite each other along a first direction, wherein the protrusions 212 of the first protrusion group 2121 are arranged in the shape of acute triangles. The plurality of protrusions 212 include a second protrusion group 2122 arranged opposite each other along a second direction, wherein the protrusions 212 of the first protrusion group 2121 are arranged in the shape of obtuse triangles. A drainage channel 2120 is formed between one protrusion 212 of the first protrusion group 2121 and one protrusion 212 of the second protrusion group 2122. A drainage channel 2120 is also formed between another protrusion 212 of the first protrusion group 2121 and another protrusion 212 of the second protrusion group 2122. Along a diagonal line of the bottom plate 21, the two drainage channels 2120 are connected to form a first flow channel 2123. Similarly, along another diagonal line of the bottom plate 21 , the two drainage channels 2120 are connected to form a second flow channel 2124 , and the first flow channel 2123 and the second flow channel 2124 form an X shape as a whole.

[0055] In some embodiments, the height of the protrusion 212 is greater than 0 and less than or equal to 1 mm. Specifically, the height of the protrusion 212 can be 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, etc. It should be noted that the batteries currently on the market need to reserve sufficient assembly gaps between the electrode terminals and the electrode assembly 10, resulting in the volume of the electrode assembly 10 not being able to be maximized. The existing battery structure usually reduces the volume of the battery cell module by reducing the assembly gap between the electrode terminal and the electrode assembly 10, and this arrangement reduces the flow channel of the electrolyte. The protrusion 212 of the present application is provided on the bottom plate 21. On the one hand, the increase in the volume of the battery cell 100 is avoided by controlling the height of the protrusion 212. On the other hand, a drainage channel 2120 can be formed between the protrusions 212 to ensure the infiltration rate of the electrolyte.

[0056] In some embodiments, the battery cell 100 further includes an insulating sheet 30. It is understandable that the insulating sheet 30 is used to coat the outer surface of the battery cell 100 before the electrode assembly 10 is loaded into the shell 20. After the coating is completed, the electrode assembly 10 and the insulating sheet 30 are loaded into the accommodating chamber together. On the one hand, the insulating sheet 30 can play a role in fixing multiple battery cell units into a whole. On the other hand, it also plays a role in protecting the electrode assembly 10. During the process of the electrode assembly 10 being loaded into the shell, the insulating sheet 30 is wrapped around the outside of the electrode assembly 10, which can prevent the electrode assembly 10 from direct contact with the shell 20, and avoid the shell 20 from causing scratches and other damage to the electrode assembly 10, so that the electrode assembly 10 is damaged during the assembly process, thereby improving product safety. In addition, the insulating sheet 30 can effectively isolate the positive and negative poles inside the battery, prevent short circuits, and thus improve the safety of the battery. Especially for high-energy-density batteries, when overcharging or short circuit occurs, the insulating sheet 30 has a certain flame retardant effect, reducing the risk of battery fire. While ensuring that the electrolyte in the shell 20 can smoothly penetrate and infiltrate the electrode assembly 10, it can also prevent the powder falling from the electrode assembly 10 from contacting the shell 20, reducing the probability of electrochemical corrosion failure of the battery and improving the safety of battery use.

[0057] In some examples, the insulating sheet 30 is attached to the side of the electrode assembly 10 facing the bottom plate 21, and the projected area of ​​the insulating sheet 30 on the bottom plate 21 is smaller than the area of ​​the bottom plate 21. It is understood that the electrode assembly 10 is located in the receiving chamber, the electrolyte can enter the receiving chamber from the periphery of the electrode assembly 10, and under the isolation of the insulating sheet 30, the electrode assembly 10 does not directly contact the bottom plate 21.

[0058] In some examples, the insulating sheet 30 is provided with an opening, which connects the accommodating chamber and the drainage channel 2120. Specifically, the insulating sheet 30 can be provided with a plurality of micro-openings, through which the electrolyte can enter the accommodating chamber, so that the insulating sheet 30 can isolate the electrode assembly 10 from the housing 20 without affecting the electrolyte's infiltration into the battery cell.

[0059] In some embodiments, the insulating sheet 30 may be a PET (Polyethylene terephthalate) film or a PI (Polyimide Film) film. PP (Polypropylene) films, commonly used in related art, both offer high- and low-temperature resistance, insulation properties, and excellent thermal conductivity. They can seal the phase change material while also adapting to the drastic temperature fluctuations of the battery cell, thereby ensuring the battery cell's service life.

[0060] Please refer to Figure 7-Figure 8 , Figure 7 yes Figure 2 The enlarged schematic diagram of the part A shown is Figure 8 yes Figure 2 The bottom view of the bottom plate 21 is shown. In some embodiments, the battery cell 100 further includes a sealing rubber particle 40, which is sealed to the injection hole 2111. The sealing rubber particle 40 can prevent the electrolyte inside the battery from leaking to the external environment under high temperature or vibration conditions.

[0061] In some embodiments, a countersunk hole 2103 is provided on the side of the bottom plate 21 facing away from the electrode assembly 10, and the countersunk hole 2103 is connected to the injection hole 2111. The battery cell 100 also includes a sealing plate 41, which is provided in the countersunk hole 2103, and the sealing plate 41 is flush with the surface of the bottom plate 21.

[0062] Specifically, the bottom plate 21 includes a hole wall forming the injection hole 2111. A seal is installed in the injection hole 2111 and abuts against the hole wall to seal the injection hole 2111. A sealing plate 41 is installed in the countersunk hole 2103. One side of the sealing plate 41 abuts against the sealing rubber particles 40 to further prevent electrolyte leakage. The other side of the sealing plate 41 is flush with the surface of the bottom plate 21 facing away from the storage space to improve the flatness of the bottom surface. In addition, the sealing plate 41 is adapted to the countersunk hole 2103 to prevent the sealing plate 41 from falling. The sealing plate 41 can be an aluminum plate.

[0063] The present application also provides a battery pack, comprising the battery cell 100 as described above.

[0064] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, based on the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A battery cell, characterized in that: include: electrode assembly; pole; A shell having a housing chamber, wherein the electrode assembly is located in the housing chamber, the electrode post is mounted on the shell and electrically connected to the electrode assembly, the shell including a bottom plate for supporting the electrode assembly, the bottom plate and the electrode post being located on different sides of the shell, a side of the bottom plate close to the housing chamber being provided with a plurality of drainage channels, the bottom plate being provided with a liquid injection hole, the liquid injection hole being connected to the plurality of drainage channels; The injection hole is used to inject electrolyte into the accommodating chamber so that the electrolyte can flow along the drainage channel to infiltrate the electrode assembly.

2. The battery cell according to claim 1, characterized in that The bottom plate includes a plate body and a plurality of protrusions, wherein the plurality of protrusions are spaced apart on a side of the plate body facing the electrode assembly, and the drainage channel is formed between any two adjacent protrusions, and the plurality of drainage channels are connected.

3. The battery cell according to claim 2, characterized in that The battery cell includes a plurality of first protrusion groups, each of the plurality of first protrusion groups includes a plurality of protrusions arranged along a first direction, and a first flow channel is formed between two adjacent first protrusion groups; The battery cell includes a plurality of second protrusion groups, each of the plurality of second protrusion groups includes a plurality of protrusions arranged along a second direction, two adjacent second protrusion groups form a second flow channel, and the first flow channel is connected to the second flow channel; The first direction intersects with the second direction.

4. The battery cell according to claim 3, characterized in that The bottom plate includes two first side edges extending along a first direction, and the first flow channel extends from one first side edge to the other first side edge; and / or; The bottom plate includes two second side edges extending along a second direction, and the second flow channel extends from one second side edge to the other second side edge.

5. The battery cell according to claim 2, characterized in that The bottom plate includes two first sides extending along a first direction, the battery cell includes a plurality of first protrusion groups connected to one of the first sides, and a second protrusion group connected to the other first side, wherein the protrusions of the first protrusion group and the protrusions of the second protrusion group are alternately arranged; The protrusions of the first protrusion group are spaced apart from the other first side and form a first flow channel, the protrusions of the second protrusion group are spaced apart from the first side and form a second flow channel, the protrusions of the first protrusion group and the adjacent protrusions of the second protrusion group are at least partially opposite and spaced apart to form a third flow channel, the first flow channel and the second flow channel are located on both sides of the third flow channel, and the first flow channel, the second flow channel and the third flow channel are interconnected to form a bent flow channel.

6. The battery cell according to claim 2, characterized in that The height of the protrusion is greater than 0 and less than or equal to 1 mm.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The battery cell further includes an insulating sheet, which is attached to a side of the electrode assembly facing the bottom plate, and an area of ​​the insulating sheet projected on the bottom plate is smaller than an area of ​​the bottom plate.

8. The battery cell according to claim 7, characterized in that: The insulating sheet is provided with an opening, and the opening is connected with the accommodating chamber and the drainage channel.

9. The battery cell according to any one of claims 1 to 6, characterized in that: The battery core further comprises sealing particles, and the sealing particles are sealed and connected to the liquid injection hole.

10. The battery cell according to claim 9, characterized in that: A countersunk hole is provided on a side of the bottom plate facing away from the electrode assembly, and the countersunk hole is connected to the injection hole. The battery cell also includes a sealing plate, which is provided in the countersunk hole. The surfaces of the sealing plate and the bottom plate are flush.

11. A battery pack, characterized in that: Comprising the battery cell according to any one of claims 1 to 10.

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