Cylindrical battery monomer and battery module

Abstract

The utility model relates to the technical field of batteries, particularly provides a cylindrical battery monomer, and aims to solve the technical problems of lithium ion deposition, battery impedance increase and influence on the cycle life and the safety of the battery caused by electrolyte consumption reduction in the circulating process of the cylindrical battery monomer. Therefore, the single cylindrical battery comprises a first insulating part which is arranged between a shell and a current collecting component of the single cylindrical battery so as to insulate the shell from the current collecting component, the first insulating part is provided with a containing cavity, and the containing cavity is used for storing electrolyte so as to supplement liquid to an electrode assembly of the single cylindrical battery. According to the utility model, the space between the current collecting component and the shell is fully utilized, and the accommodating cavity for storing the electrolyte is arranged in the insulating part, so that the electrolyte in the accommodating cavity is timely released for supplementing when the cylindrical battery monomer needs to be supplemented, the problem of failure of the cylindrical battery monomer caused by the dry electrolyte is avoided, and the service life is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and specifically provides a cylindrical battery monomer and a battery module. Background Art

[0002] At present, with the update and iteration of the structure of cylindrical batteries with steel shells, cylindrical batteries have developed from 18650 and 21700 to 4680 series large cylindrical batteries with larger volume and higher energy density. The design of full-ears not only further reduces the internal resistance during the use of the battery, but also improves the charging and discharging efficiency, and also better improves the service life of the battery. However, due to the high hardness of the steel shell and the limited space between the coil core and the steel shell designed to increase the energy density, certain problems have been caused for the subsequent injection of the electrolyte. The electrolyte of the cylindrical battery cell needs to be injected through the injection hole of the negative electrode at high pressure, but if the injection amount is too large, it will cause the electrolyte to overflow. Therefore, the amount of electrolyte injection of the cylindrical battery is subject to certain restrictions, resulting in too little free electrolyte in the battery.

[0003] During the battery cycle, the electrolyte is in a state of continuous consumption. A lack of electrolyte will lead to the deposition of lithium ions and increased battery impedance during the cycle, which will have an adverse effect on the battery's cycle life and safety. This problem needs to be solved urgently. Utility Model Content

[0004] The utility model aims to solve the above technical problem, that is, to solve the technical problem that during the cycle of cylindrical battery cells, lithium ion deposition and increased battery impedance are caused by reduced electrolyte consumption, which affects the cycle life and safety of the battery.

[0005] In a first aspect, the utility model provides a cylindrical battery cell, comprising: a first insulating member, arranged between a shell and a current collecting member of the cylindrical battery cell, so as to insulate the shell and the current collecting member; the first insulating member is provided with a receiving cavity, and the receiving cavity is used to store electrolyte to replenish the electrode assembly of the cylindrical battery cell.

[0006] In the above technical solution, the first insulating member is arranged between the shell and the current collecting member of the cylindrical battery cell, and the space between the current collecting member and the shell is fully utilized. A receiving cavity for storing electrolyte is arranged in the insulating member. When the cylindrical battery cell needs to be replenished, the electrolyte in the receiving cavity is released in time for replenishment, thereby avoiding the failure problem of the cylindrical battery cell due to the drying up of the electrolyte and extending the service life.

[0007] In some embodiments, the first insulating member includes: a first isolating portion; a second isolating portion, the second isolating portion being arranged opposite to the first isolating portion; a third isolating portion being connected to the outer periphery of the first isolating portion and the outer periphery of the second isolating portion, respectively; a through hole, arranged at the center of the first insulating member, for the pole of the cylindrical battery cell to pass through; the accommodating cavity is jointly constituted by the first isolating portion, the second isolating portion, the third isolating portion and the hole wall of the through hole.

[0008] In some embodiments, the second isolating portion is configured such that, under the action of gravity, the electrolyte in the containing cavity can flow out along the second isolating portion.

[0009] In some embodiments, the second isolation portion includes a first side surface and a second side surface, the first side surface is an inclined surface, and the second side surface is a horizontal surface; wherein the first side surface is a side of the second isolation portion facing the accommodating cavity, and the second side surface is a side of the second isolation portion facing away from the accommodating cavity.

[0010] In some embodiments, the second side is provided with a weak portion, and the pole is provided with a puncture assembly, and the puncture assembly is configured such that: under the action of an external force, the puncture assembly punctures the weak portion, and the electrolyte in the accommodating cavity flows out.

[0011] In some embodiments, the weak portion is disposed close to the through hole, and the weak portion is a pit disposed on the second side surface.

[0012] In some embodiments, the pole is provided with a groove opening away from the first insulating member, and a through groove connected to the groove, and the through groove extends in a horizontal direction; the puncture assembly includes a vertical portion and a puncture portion, the vertical portion is provided in the groove, and the puncture portion passes through the through groove and is connected to the vertical portion.

[0013] In some embodiments, the puncture assembly includes a limiting portion, which is arranged at an end of the vertical portion away from the first insulating member, and the groove includes a sinking platform, and the limiting portion is accommodated in the sinking platform.

[0014] In some embodiments, the pole includes a main body and a first flange and a second flange arranged at both ends of the main body, the first flange is arranged on the outer side of the shell, and the second flange is arranged on the inner side of the shell; the groove passes through the first flange, the main body and the second flange, and the through groove is arranged on the second flange.

[0015] In some embodiments, the puncturing portion includes a connecting rod and a probe disposed at an end of the connecting rod, and a projection of the probe on the second side surface is located within the weak portion.

[0016] In some embodiments, the through slot is configured so that the probe can rotate within a preset range of the through slot.

[0017] In some embodiments, the cross-section of the through groove is fan-shaped.

[0018] In some embodiments, a plug-in groove is provided on a side of the limiting portion away from the vertical portion.

[0019] In some embodiments, the cylindrical battery cell includes a second insulating member disposed between the second flange and the shell to insulate the pole from the shell.

[0020] In a second aspect, the utility model further provides a battery module, wherein the battery module comprises a plurality of the above-mentioned cylindrical battery cells.

[0021] The advantages of the battery module and the cylindrical battery cell described above over the prior art are the same, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a partial cross-sectional view of a cylindrical battery cell provided by an embodiment of the utility model;

[0024] Figure 2 It is a bottom view of the first insulating member provided by the embodiment of the utility model;

[0025] Figure 3 is a top view of a first insulating member provided in an embodiment of the utility model;

[0026] Figure 4 It is a schematic diagram of the structure of the pole provided by the embodiment of the utility model;

[0027] Figure 5 It is a schematic diagram of the structure of the puncture assembly provided by an embodiment of the utility model;

[0028] Figure 6 yes Figure 4 Cross-sectional view of the center pole in the AA direction.

[0029] List of reference numerals:

[0030] 1. First insulating member; 11. First isolating portion; 12. Second isolating portion; 13. Third isolating portion; 14. Through hole; 121. First side surface; 122. Second side surface; 1221. Weak portion; 2. Shell; 3. Current collecting member; 4. Accommodating chamber; 5. Pole; 51. Piercing assembly; 52. Groove; 53. Through groove; 511. Vertical portion; 512. Piercing portion; 513. Position limiting portion; 521. Sinking platform; 54. Main body; 55. First flange; 56. Second flange; 5121. Connecting rod; 5122. Probe; 5131. Plug-in slot; 6. Second insulating member DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0032] It should be noted that in the description of the present invention, the terms "inside", "outside", "top", "bottom" and other terms indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0033] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0035] Please refer to Figures 1 to 6 , Figures 1 to 6 A schematic diagram of the structure of a cylindrical battery cell provided in an embodiment of the utility model.

[0036] like Figures 1 to 3As shown, the cylindrical battery cell of the utility model includes a shell 2, one end of the shell 2 has an opening, a cover plate is provided at the opening, an electrode assembly is provided inside the shell 2, the cover plate is directly or indirectly electrically connected to the electrode assembly, and a pole 5 is provided on the side wall opposite to the shell 2, and the pole 5 is directly or indirectly electrically connected to the electrode assembly. In this embodiment, the end provided with the pole 5 is the positive electrode side of the cylindrical battery cell, and the positive electrode side specifically includes the pole 5, the first insulating member 1, the second insulating member 6 and the current collecting member 3. The first insulating member 1 is provided between the shell 2 and the current collecting member 3 to prevent the shell 2 and the current collecting member 3 from being electrically connected, causing a short circuit in the battery. The second insulating member 6 is provided between the pole 5 and the shell 2 to prevent the pole 5 and the shell 2 from overlapping, causing a short circuit in the battery, and the current collecting member 3 is welded to the pole 5 and the electrode assembly respectively. During the battery cycle, the electrolyte in the electrode assembly is in a state of continuous consumption. The reduction of electrolyte will lead to lithium ion deposition and increase of battery impedance during the cycle process, which will have an adverse effect on the cycle life and safety of the battery. The prior art adds space for placing electrolyte between the cover plate and the current collecting member of the battery to replenish the battery. The inventors found that adding space between the cover plate and the current collecting plate would increase the volume of the shell 2 or reduce the capacity of the battery. In order to solve the above problems, in this embodiment, a accommodating chamber 4 is provided on the first insulating member 1, and the accommodating chamber 4 is used to store electrolyte to replenish the electrode assembly inside the battery. The space between the current collecting member 3 and the shell 2 is fully utilized, and a accommodating chamber 4 for storing electrolyte is provided in the insulating member without additionally increasing the volume of the shell 2. When the electrode assembly of the cylindrical battery cell needs to be replenished, the electrolyte in the accommodating chamber 4 is released in time for replenishment, thereby avoiding the failure of the cylindrical battery cell due to the drying up of the electrolyte and extending the service life.

[0037] like Figures 1 to 3As shown, the shape of the first insulating member 1 is adapted to the opening of the cylindrical battery. The first insulating member 1 includes: a first isolating portion 11, a second isolating portion 12 and a third isolating portion 13. The first isolating portion 11 and the second isolating portion 12 are arranged opposite to each other, and the third isolating portion 13 is connected to the outer periphery of the first isolating portion 11 and the second isolating portion 12 respectively. A through hole 14 is provided in the center of the first insulating member 1 for the pole 5 to pass through and be welded with the current collecting member 3. The accommodating chamber 4 for storing electrolyte is composed of the first isolating portion 11, the second isolating portion 12, the third isolating portion 13 and the hole wall of the through hole 14. The structure of the first insulating member 1 is simple and the cost is low. During the production process, the electrolyte in the accommodating chamber 4 of the first insulating member 1 can be injected before the first insulating member 1 is processed and formed, or it can be injected after the first insulating member 1 is processed and formed. In this embodiment, the second isolating portion 12 is configured so that the electrolyte in the accommodating chamber 4 can flow out along the second isolating portion 12 toward one side of the accommodating chamber 4 under the action of gravity. Specifically, the second isolating portion 12 can be set to an inclined surface, a curved surface or other shapes, as long as the electrolyte can flow out under the action of its own gravity. Further, the second isolating portion 12 includes a first side surface 121 and a second side surface 122, the first side surface 121 is an inclined surface, and the second side surface 122 is a horizontal surface; wherein the first side surface 121 is a side of the second isolating portion 12 facing the accommodating cavity 4, and the second side surface 122 is a side of the second isolating portion 12 facing away from the accommodating cavity 4.

[0038] like Figures 1 to 6As shown, in this embodiment, the second side surface 122 is provided with a weak portion 1221, and the pole 5 is provided with a puncture assembly 51, which is configured such that: under the action of an external force, the puncture assembly 51 punctures the weak portion 1221, and the electrolyte in the accommodating chamber 4 flows out. Specifically, the weak portion 1221 in this embodiment is arranged close to the through hole 14, which is convenient for the puncture assembly 51 arranged on the pole 5 to puncture, and the weak portion 1221 is a pit processed on the surface of the second side surface 122, and the thickness of the pit is smaller than that of other areas of the second side surface 122. The weak portion 1221 can also be in other shapes, as long as it is convenient for puncture, and is not limited here. Furthermore, the pole 5 is provided with a groove 52 with an opening facing away from the first insulating member 1, and a through groove 53 extending in the horizontal direction and connected to the groove 52; the puncture assembly 51 specifically includes a vertical portion 511 and a puncture portion 512, the vertical portion 511 is provided in the groove 52, the puncture portion 512 passes through the through groove 53 and is connected to the vertical portion 511, and the opening of the groove 52 faces outward, which can facilitate manual refilling operations from the outside of the battery. In some embodiments, the puncture portion 512 specifically includes a connecting rod 5121 and a probe 5122, the probe 5122 is provided at the end of the connecting rod 5121, and the projection of the probe 5122 on the second side surface 122 is located in the weak portion 1221. In this embodiment, the puncture assembly 51 also includes a limiting portion 513, which is provided at one end of the vertical portion 511 away from the first insulating member 1, and the groove 52 includes a sink 521, and the limiting portion 513 is accommodated in the sink 521 to prevent the puncture assembly 51 from sinking due to the vibration of the battery. Furthermore, the pole 5 includes a main body 54 and a first flange 55 and a second flange 56 provided at both ends of the main body 54. The first flange 55 is provided on the outer side of the housing 2, and the second flange 56 is provided on the inner side of the housing 2. During the battery assembly process, the pole 5 is fixed to the housing 2 by riveting. The first flange 55 can prevent the pole 5 from relative displacement in the vertical direction, and the second flange 56 can play a role in fixing the second insulating member 6. The groove 52 passes through the first flange 55, the main body 54 and the second flange 56, and the through groove 53 is provided on the second flange 56. Furthermore, the through groove 53 is configured so that the probe 5122 can rotate within a preset range of the through groove 53, so that the external force drives the vertical part 511 to drive the connecting rod 5121 to rotate, and the connecting rod 5121 drives the probe 5122 to rotate, and the probe 5122 keeps cutting the weak part 1221 back and forth to achieve the purpose of piercing the accommodating cavity 4. Specifically, in this embodiment, the cross-section of the through slot 53 is fan-shaped, which is compatible with the circular motion of the probe 5122. In some embodiments, a plug-in slot 5131 is provided on one side of the stopper 513 away from the vertical portion 511. The plug-in slot 5131 can be a strip slot, a cross slot, or other forms, as long as it can be plugged into a tool, which is not limited here. Since the size of the battery is small, in order to facilitate driving the puncture assembly 51, the strip slot or the cross slot can be driven by a screwdriver, which is efficient and convenient.

[0039] The utility model also provides a battery module having a plurality of cylindrical battery cells. The beneficial effects of the battery module are the same as the advantages of the cylindrical battery cells in this embodiment over the prior art, and will not be described in detail herein.

[0040] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A cylindrical battery cell, characterized in that: include: The first insulating member is disposed between the shell and the current collecting member of the cylindrical battery cell to insulate the shell and the current collecting member. The first insulating member is provided with a receiving cavity for storing electrolyte to replenish the electrode assembly of the cylindrical battery cell.

2. The cylindrical battery cell according to claim 1, characterized in that: The first insulating member includes: a first isolating portion; a second isolating portion, the second isolating portion is arranged opposite to the first isolating portion; a third isolating portion, connected to the outer periphery of the first isolating portion and the outer periphery of the second isolating portion respectively; a through hole, arranged at the center of the first insulating member, for the pole of the cylindrical battery cell to pass through; the accommodating cavity is jointly constituted by the first isolating portion, the second isolating portion, the third isolating portion and the hole wall of the through hole.

3. The cylindrical battery cell according to claim 2, characterized in that: The second isolating portion is configured such that, under the action of gravity, the electrolyte in the accommodating cavity can flow out along the second isolating portion.

4. The cylindrical battery cell according to claim 3, characterized in that: The second isolation portion includes a first side surface and a second side surface, the first side surface is an inclined surface, and the second side surface is a horizontal surface; wherein the first side surface is a surface of the second isolation portion facing the accommodating cavity, and the second side surface is a surface of the second isolation portion facing away from the accommodating cavity.

5. The cylindrical battery cell according to claim 4, characterized in that: The second side surface is provided with a weak portion, and the pole is provided with a puncture component, and the puncture component is configured such that: under the action of an external force, the puncture component punctures the weak portion, and the electrolyte in the accommodating cavity flows out.

6. The cylindrical battery cell according to claim 5, characterized in that: The weak portion is arranged close to the through hole, and the weak portion is a pit arranged on the surface of the second side surface.

7. The cylindrical battery cell according to claim 5, characterized in that: The pole is provided with a groove opening away from the first insulating member, and a through groove connected to the groove, and the through groove extends in a horizontal direction; the puncture assembly includes a vertical portion and a puncture portion, the vertical portion is provided in the groove, and the puncture portion passes through the through groove and is connected to the vertical portion.

8. The cylindrical battery cell according to claim 7, characterized in that: The puncture assembly includes a limiting portion, which is arranged at an end of the vertical portion away from the first insulating member. The groove includes a sinking platform, and the limiting portion is accommodated in the sinking platform.

9. The cylindrical battery cell according to claim 7, characterized in that: The pole includes a main body and a first flange and a second flange arranged at both ends of the main body, the first flange is arranged on the outer side of the shell, and the second flange is arranged on the inner side of the shell; the groove passes through the first flange, the main body and the second flange, and the through groove is arranged on the second flange.

10. The battery cell according to claim 7, characterized in that: The puncturing portion includes a connecting rod and a probe disposed at an end of the connecting rod, and a projection of the probe on the second side surface is located within the weak portion.

11. The battery cell according to claim 10, characterized in that: The through slot is configured so that the probe can rotate within a preset range of the through slot.

12. The battery cell according to claim 11, characterized in that: The cross section of the through groove is fan-shaped.

13. The cylindrical battery cell according to claim 8, characterized in that: A plug-in groove is provided on a side of the limiting portion away from the vertical portion.

14. The cylindrical battery cell according to claim 9, characterized in that: The cylindrical battery cell includes a second insulating member disposed between the second flange and the shell to insulate the pole from the shell.

15. A battery module, characterized in that: The invention comprises a plurality of cylindrical battery cells as described in any one of claims 1 to 14.

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