Rubber-coated laminated core and button type lithium ion battery

Abstract

The utility model relates to the technical field of lithium ion batteries, in particular to a rubber-coated laminated core and a button type lithium ion battery, the rubber-coated laminated core comprises a battery core body, a positive tab group and a negative tab group, the positive tab group and the negative tab group are respectively and correspondingly positioned on the end surfaces of two opposite ends of the battery core body, and the rubber-coated laminated core also comprises a positive tab strip adhesive tape and a negative tab strip adhesive tape, the positive tab strip adhesive tape is used for sticking and fixing a positive tab group, the negative tab strip adhesive tape is used for sticking and fixing a negative tab group, and the positive tab strip adhesive tape and the negative tab strip adhesive tape are L-shaped and are stuck on the same end surface and side surface of the battery cell body. According to the utility model, the encapsulation laminated core adopts an L-shaped encapsulation mode, and the positive tab adhesive tape and the negative tab adhesive tape are adhered to the same end surface and the same side surface of the battery cell body, so that the problem that a bent angle exceeding the diameter is generated in the diameter direction of the surface of the battery cell in which the tab group is encapsulated with the insulation paste is solved; and poor welding seams caused by interference of the bending angle of the insulating glue on peripheral welding of the upper and lower covers of the battery are avoided, so that the welding yield and the first pass yield of products are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion batteries, in particular to a rubber-coated laminated core and button-type lithium ion battery. Background Art

[0002] Due to the advantages of high energy density, high power density, many cycles, and long storage time, lithium-ion batteries have broad application prospects in electric vehicles, electric bicycles and other electric vehicles, as well as large and medium-sized electric equipment such as energy storage facilities. They have become the key to solving global problems such as energy crisis and environmental pollution. With the continuous development of microelectronics technology, the application of button lithium-ion batteries is becoming more and more extensive. Button lithium batteries are mainly used in computer motherboards, MP3 watches, calculators, IC cards, electronic dictionaries, tax control machines, Bluetooth headsets, hand-cranked rechargeable flashlights, toys, walkie-talkies and other products. They have many advantages such as good operating temperature, good sealing performance, long storage time, and stable discharge voltage.

[0003] The battery cell of the lithium-ion battery needs to be wrapped or wound with tape to ensure the overall structural stability of the battery cell. In the prior art, the battery cell generally adopts a C-type rubber encapsulation structure, that is, the positive and negative pole ears are attached to the insulating tape, and the two ends of the insulating tape are adhered to the positive and negative pole ears at the upper and lower ends of the stacked core by about 2-3mm. The bent tape has a bending angle in the radial direction of the stacked core and exceeds the diameter of the stacked core. In the prior art, the insulating tape has a problem of an angle that exceeds the diameter in the diameter direction of the battery cell surface, and the interference of the insulating tape angle with the welding around the upper and lower covers of the battery produces a poor weld, which reduces the welding yield and pass rate of the battery. Utility Model Content

[0004] In view of this, the purpose of the utility model is to provide a rubber-coated stacked core and button-type lithium-ion battery, optimize the rubber-coating method, effectively improve the welding yield around the battery, and improve the product production yield.

[0005] The utility model solves the above technical problems through the following technical means:

[0006] In the first aspect, the utility model provides a rubber-coated stacked core, including a battery cell body, a positive electrode ear group and a negative electrode ear group, wherein the positive electrode ear group and the negative electrode ear group are both connected to the battery cell body, and the positive electrode ear group and the negative electrode ear group are respectively located on the end faces of the opposite ends of the battery cell body, and also include positive electrode ear strip tape and negative electrode ear strip tape, wherein the positive electrode ear strip tape is used to stick and fix the positive electrode ear group, and the negative electrode ear strip tape is used to stick and fix the negative electrode ear group, and the positive electrode ear strip tape and the negative electrode ear strip tape are both L-shaped and stuck on the same end face and side face of the battery cell body.

[0007] In combination with the first aspect, in some embodiments, the battery cell body has a first end face and a second end face, one end of the positive electrode ear group is connected to the battery cell body, extends and bends along the side of the battery cell body to the other end of the positive electrode ear group is located on the first end face, and one end of the negative electrode ear group is connected to the battery cell body, extends and bends along the side of the battery cell body to the other end of the negative electrode ear group is located on the second end face.

[0008] In combination with the first aspect, in some embodiments, the positive electrode ear strip tape is pasted on the positive electrode ear group, one end of the positive electrode ear group tape is pasted on the second end face, and the other end is pasted on the positive electrode ear group on the side of the battery cell body; the negative electrode ear strip tape is pasted on the negative electrode ear group, one end of the negative electrode ear strip tape is pasted on the negative electrode ear group on the side of the battery cell body, and the other end is pasted on the second end face.

[0009] In combination with the first aspect, in some embodiments, the negative electrode ear strip tape is pasted on the negative electrode ear group, one end of the negative electrode ear strip tape is pasted on the first end face, and the other end is pasted on the negative electrode ear group on the side of the battery cell body, and the positive electrode ear strip tape is pasted on the positive electrode ear group, one end of the positive electrode ear strip tape is pasted on the positive electrode ear group on the side of the battery cell body, and the other end is pasted on the first end face.

[0010] In combination with the first aspect, in some embodiments, a fastening adhesive strip is further adhered to the battery cell body.

[0011] In a second aspect, the utility model further provides a button-type lithium-ion battery, comprising the encapsulated laminated core described in the first aspect.

[0012] In combination with the second aspect, in some embodiments, the button-type lithium-ion battery further includes a shell and a cover, the shell and the cover constitute a accommodating cavity for accommodating the encapsulated battery cell, the negative electrode ear group is welded to the inner bottom of the shell as a negative electrode, and the positive electrode ear group is welded to the inner side of the cover as a positive electrode.

[0013] In combination with the second aspect, in some embodiments, the button-type lithium-ion battery further includes a shell and a cover, the shell and the cover constitute a housing cavity for accommodating the encapsulated battery cell, the positive electrode ear group is welded to the inner bottom of the shell as a positive electrode, and the negative electrode ear group is welded to the inner side of the cover as a negative electrode.

[0014] The rubber-coated core stacking of the utility model adopts an L-shaped rubber-coating method. The positive ear tape and the negative ear tape are both L-shaped and pasted on the same end face and side face of the battery body, which solves the problem of the bending angle of the insulation rubber wrapped around the ear group exceeding the diameter in the diameter direction of the battery surface, and avoids the poor weld caused by the interference of the bending angle of the insulation rubber with the welding around the upper and lower covers of the battery, thereby improving the product welding yield and pass rate. The "L"-shaped rubber-coating method of the stacking core of the utility model is not only suitable for fully sealed laminated structure batteries, but also can be applied to traditional upper and lower cover structures, avoiding the excessive part of the insulation rubber from being embedded in the sealing ring, preventing poor sealing of the sealing, etc.

[0015] The button-type lithium-ion battery of the utility model adopts an L-shaped encapsulation method for the core stacking, which is optimized from the traditional "C"-shaped insulating rubber encapsulation method to an "L"-shaped one, thereby improving the welding yield of the battery at the periphery and improving the product production yield, while reducing the number of ear strip layers welded to the cover body, thereby increasing the available space inside the battery and effectively improving the energy density of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of the traditional C-type encapsulation structure of the battery;

[0017] Figure 2 is a schematic structural diagram of the battery cell body in Example 1;

[0018] Figure 3 is a diagram showing the starting position of the positive electrode ear tape in Example 1;

[0019] Figure 4 is a diagram showing the bending direction of the positive electrode ear tape in Example 1;

[0020] Figure 5 This is a diagram showing the result of pasting the positive electrode ear tape in Example 1;

[0021] Figure 6 It is a schematic diagram of the structure of the rubber-coated laminated core of Example 1;

[0022] Figure 7 is a diagram showing the connection between the negative electrode ear group and the housing in Example 3;

[0023] Figure 8 This is a schematic diagram of the structure after the rubber-encapsulated laminated core enters the shell in Example 3;

[0024] Fig. 9 is a schematic diagram of the structure after the negative electrode ear group and the cover body are welded in Example 3;

[0025] Fig.10 is a cross-sectional view of a button-type lithium-ion battery of Example 3;

[0026] Fig.11 yes Fig.10A schematic diagram of the enlarged structure at A in the middle;

[0027] Among them, the battery cell body 1, the first end face 11, the second end face 12, the side face 13, the positive electrode ear group 2, the negative electrode ear group 3, the fastening rubber strip 4, the positive electrode ear strip tape 5, the negative electrode ear strip tape 6, the shell 71, the cover 72, and the insulating tape 8. DETAILED DESCRIPTION

[0028] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the illustrations provided in the following embodiments are only for exemplary descriptions, and they are only schematic diagrams, not physical diagrams, and cannot be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts in the figures may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the figures may be omitted.

[0029] The same or similar numbers in the figures of the embodiments of the present invention correspond to the same or similar parts. In the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "back", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the figures, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the figures are only used for illustrative purposes and cannot be understood as limitations on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] Please refer to Figure 1 , the traditional battery C-type encapsulation structure assembly: the insulating tape 8 is attached to the positive and negative pole ears, and the two ends of the insulating tape are correspondingly attached to the positive and negative pole ears at the upper and lower ends of the stacked core by about 2-3mm. The bent insulating tape 8 generates two bending angles in the radial direction of the stacked core, and the generated bending angle exceeds the diameter of the stacked core. The process flow of the traditional battery C-type encapsulation is as follows:

[0031] Stack the core → Super welding of negative electrode group → Super welding of positive electrode group → Wrap the positive and negative electrode ears with "C" type glue → Laser welding of lower cover → Stack the core into shell → Weld the upper cover → Bend the positive electrode ear strip → Close the upper and lower covers → Weld the periphery of the upper and lower covers.

[0032] The above-mentioned traditional C-type rubber coating of the battery cell produces a bending angle that exceeds the diameter in the diameter direction of the battery cell surface. The interference of the bending angle with the welding around the upper and lower covers of the battery will produce poor welds, reducing the welding yield and straight-through rate of the battery. To this end, the utility model proposes a rubber-coated stacked core and button-type lithium-ion battery.

[0033] The following is a detailed description of the rubber-coated stacked core and button-type lithium-ion battery of the present invention through Examples 1-4.

[0034] Example 1

[0035] Please refer to Figure 2-6 The rubber-coated stacked core of this embodiment includes a battery cell body 1, a positive electrode ear group 2 and a negative electrode ear group 3. The positive electrode ear group 2 and the negative electrode ear group 3 are both connected to the battery cell body 1, and the positive electrode ear group 2 and the negative electrode ear group 3 are respectively located on the end faces of the opposite ends of the battery cell body 1. Specifically, the battery cell body 1 includes a plurality of stacked positive electrode sheets, a plurality of negative electrode sheets and a plurality of diaphragms. The plurality of positive electrode sheets, a plurality of negative electrode sheets and a plurality of diaphragms are stacked to form the battery cell body 1. A fastening rubber strip 4 is pasted on the battery cell body 1. The fastening rubber strip 4 is used to fix the stacked positive electrode sheets, a plurality of negative electrode sheets and a plurality of diaphragms to prevent them from spreading out and affecting the use of the battery cell. The positive electrode ear group 2 is fixedly connected to the positive electrode sheet, and the negative electrode ear group 3 is fixedly connected to the negative electrode sheet.

[0036] The rubber-coated core stack of this embodiment also includes a positive ear tape 5 and a negative ear tape 6. The positive ear tape 5 is used to stick and fix the positive ear group 2, and the negative ear tape 6 is used to stick and fix the negative ear group 3. The positive ear tape 5 and the negative ear tape 6 are both L-shaped and stuck on the same end face and side face of the battery body 1.

[0037] Specifically, the battery cell body 1 has a first end face 11 and a second end face 12 along the direction in which the positive electrode sheet and the negative electrode sheet are stacked, and a side face 13 for connecting the first end face 11 and the second end face 12. One end of the positive electrode ear group 2 is connected to the positive electrode sheet of the battery cell body 1, and is led out from the second end face 12 of the battery cell body 1, extends and is bent along the side face 13 of the battery cell body 1 until the other end of the positive electrode ear group 2 is located on the first end face 11, and one end of the negative electrode ear group 3 is connected to the battery cell body 1, and is led out from the first end face 11 of the battery cell body 1, and is extended and is bent along the side face 13 of the battery cell body 1 until the other end of the negative electrode ear group 3 is located on the second end face 12.

[0038] The positive electrode ear strip tape 5 is pasted on the positive electrode ear group 2, one end of the positive electrode ear strip tape 5 is pasted on the second end surface 12, and the other end is pasted on the positive electrode ear group 2 on the side surface 13 of the battery body 1, and the negative electrode ear strip tape 6 is pasted on the negative electrode ear group 3, one end of the negative electrode ear strip tape 6 is pasted on the negative electrode ear group 3 on the side surface 13 of the battery body 1, and the other end is pasted on the second end surface 12. In this embodiment, there is no positive electrode ear strip tape 5 and negative electrode ear strip tape 6 on the first end surface 11 of the battery body 1.

[0039] The assembly process of the rubber-coated laminated core of this embodiment is as follows:

[0040] After the positive and negative terminal groups 3 are welded, insulating glue is pasted on the second end surface 12 (see Figure 3 ), the insulating glue covers the starting position of the positive tab group 2 (the position connected to the positive electrode sheet), and the insulating glue extends along the extension direction of the positive tab group 2 and is pasted on the side 13 of the battery body 1 (please refer to Figure 4 ), as the positive electrode ear strip tape 5, the positive electrode ear group 2 is bent to the first end surface 11 (please refer to Figure 5 ); Similarly, another insulating adhesive is pasted to cover the connection end of the negative electrode ear group 3 and the negative electrode sheet, and is extended along the extension direction of the negative electrode ear group 3 and pasted on the side 13 of the battery body 1 (please refer to Figure 5 ), continue to stick it on the second end surface 12 along the bending direction of the negative electrode ear group 3, as the negative electrode ear strip tape 6, the negative electrode ear group 3 is bent to the second end surface 12 (please refer to Figure 6 The positive ear tape 5 and the negative ear tape 6 are both L-shaped adhesive tapes, which are optimized by bending two layers and one layer. The height of the insulating adhesive does not exceed the surface of the welding surface around the battery core, that is, there is no insulating adhesive on the first end surface 11 of the battery core body 1.

[0041] The rubber-coated core stacking of the utility model adopts an L-shaped rubber-coating method. The positive ear tape and the negative ear tape are both L-shaped and pasted on the same end face and side face of the battery body, which solves the problem of the bending angle of the insulation rubber wrapped around the ear group exceeding the diameter in the diameter direction of the battery surface, and avoids the poor weld caused by the interference of the bending angle of the insulation rubber with the welding around the upper and lower covers of the battery, thereby improving the product welding yield and pass rate. The "L"-shaped rubber-coating method of the stacking core of the utility model is not only suitable for fully sealed laminated structure batteries, but also can be applied to traditional upper and lower cover structures, avoiding the excessive part of the insulation rubber from being embedded in the sealing ring, preventing poor sealing of the sealing, etc.

[0042] Example 2

[0043] The difference between the rubber-coated core stack of this embodiment and the embodiment 1 is that the negative electrode ear strip tape 6 is pasted on the negative electrode ear group 3, one end of the negative electrode ear strip tape 6 is pasted on the first end surface 11, and the other end is pasted on the negative electrode ear group 3 on the side surface 13 of the battery body 1, and the positive electrode ear strip tape 5 is pasted on the positive electrode ear group 2, one end of the positive electrode ear strip tape 5 is pasted on the positive electrode ear group 2 on the side surface 13 of the battery body 1, and the other end is pasted on the first end surface 11. The other structures are the same as those of the embodiment 1.

[0044] Example 3

[0045] Please refer to Figure 7-11This embodiment describes a button-type lithium-ion battery, including the rubber-coated laminated core described in Embodiment 1. The button-type lithium-ion battery of this embodiment also includes a shell 71 and a cover 72, the shell 71 and the cover 72 constitute a receiving cavity for receiving the rubber-coated laminated core, the negative electrode ear group 3 is welded to the inner bottom of the shell 71 as the negative electrode, and the positive electrode ear group 2 is welded to the inner side of the cover 72 as the positive electrode.

[0046] Please continue to refer to Figure 7-9 The assembly process of the button-type lithium-ion battery of this embodiment is as follows:

[0047] Core stacking → negative electrode group super welding → positive electrode group super welding → positive electrode ear strip winding with green glue → positive and negative electrode ear group sticking "L" type glue → lower cover laser welding → core stacking into shell → upper cover welding → upper and lower cover box cover → upper and lower cover periphery welding.

[0048] It should be noted that the negative electrode ear group 3 of the button-type lithium-ion battery of this embodiment is bent twice after entering the shell 71, and is fixed to the inner bottom of the shell 71 by internal laser welding. Alternatively, the negative electrode ear group 3 and the inner bottom of the shell 71 may be fixed by external laser welding, in which case the negative electrode ear group 3 only needs to be bent once.

[0049] Example 4

[0050] This embodiment describes a button-type lithium-ion battery, including the rubber-coated laminated core described in Embodiment 2. The button-type lithium-ion battery of this embodiment also includes a shell 71 and a cover 72, the shell 71 and the cover 72 constitute a receiving cavity for receiving the rubber-coated laminated core, the positive electrode ear group 2 is welded to the inner bottom of the shell 71 as the positive electrode, and the negative electrode ear group 3 is welded to the inner side of the cover 72 as the negative electrode.

[0051] The above embodiments are only used to illustrate the technical solution of the utility model and are not intended to limit it. Although the utility model is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model. The technology, shape, and structure that are not described in detail in the utility model are all well-known technologies.

Claims

1. A rubber-coated stacked core, comprising a battery body, a positive electrode ear group and a negative electrode ear group, wherein the positive electrode ear group and the negative electrode ear group are both connected to the battery body, and the positive electrode ear group and the negative electrode ear group are respectively located on the end surfaces of the opposite ends of the battery body, characterized in that: It also includes a positive ear tape and a negative ear tape. The positive ear tape is used to stick and fix the positive ear group, and the negative ear tape is used to stick and fix the negative ear group. The positive ear tape and the negative ear tape are both L-shaped and stuck on the same end face and side face of the battery body.

2. The rubber-coated laminated core according to claim 1, characterized in that: The battery cell body has a first end face and a second end face, one end of the positive electrode ear group is connected to the battery cell body, extends and bends along the side of the battery cell body to the other end of the positive electrode ear group is located on the first end face, and one end of the negative electrode ear group is connected to the battery cell body, extends and bends along the side of the battery cell body to the other end of the negative electrode ear group is located on the second end face.

3. The rubber-coated laminated core according to claim 2, characterized in that: The positive ear strip tape is pasted on the positive ear group, one end of the positive ear group tape is pasted on the second end surface, and the other end is pasted on the positive ear group on the side of the battery body. The negative ear strip tape is pasted on the negative ear group, one end of the negative ear strip tape is pasted on the negative ear group on the side of the battery body, and the other end is pasted on the second end surface.

4. The rubber-coated laminated core according to claim 2, characterized in that: The negative ear strip tape is pasted on the negative ear group, one end of the negative ear strip tape is pasted on the first end surface, and the other end is pasted on the negative ear group on the side of the battery body. The positive ear strip tape is pasted on the positive ear group, one end of the positive ear strip tape is pasted on the positive ear group on the side of the battery body, and the other end is pasted on the first end surface.

5. The rubber-coated laminated core according to claim 1, characterized in that: A fastening rubber strip is also adhered to the battery body.

6. Button-type lithium-ion battery, characterized in that: It comprises the encapsulated core stack as described in any one of claims 1 to 5.

7. The button-type lithium-ion battery according to claim 6, characterized in that: The button-type lithium-ion battery also includes a shell and a cover, which form a housing for accommodating the rubber-coated laminated core. The negative electrode ear group is welded to the inner bottom of the shell as a negative electrode, and the positive electrode ear group is welded to the inner side of the cover as a positive electrode.

8. The button-type lithium-ion battery according to claim 6, characterized in that: The button-type lithium-ion battery also includes a shell and a cover, which form a housing for accommodating the rubber-coated laminated core. The positive electrode ear group is welded to the inner bottom of the shell as a positive electrode, and the negative electrode ear group is welded to the inner side of the cover as a negative electrode.

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