Hot melt adhesive, battery monomer, battery and electrochemical device

Abstract

The utility model relates to the technical field of secondary batteries, and particularly provides a hot melt adhesive, a battery monomer, a battery and an electrochemical device. The adhesive tape is used for adhering a packaging shell to the surface of a naked battery cell, and comprises at least one adhesive layer which is used for increasing the friction force between the packaging shell and the naked battery cell and comprises a plurality of lug bosses; the base material layer is attached to the bonding layer; according to the utility model, the plurality of convex parts on the bonding layer are attached to the base material layer to increase the roughness of the hot melt adhesive, so that the anti-falling performance of the battery is improved on the premise that the thickness of the battery does not need to be increased.

Description

Technical Field

[0001] The utility model belongs to the technical field of secondary batteries, and specifically provides a hot melt adhesive, a battery monomer, a battery and an electrochemical device. Background Art

[0002] During the use of lithium-ion batteries, in order to improve the drop resistance of lithium-ion batteries, hot melt adhesive is usually attached to the surface of the bare battery cell, and in this way, the bare battery cell and the aluminum-plastic film are bonded together, that is, relative sliding between the bare battery cell and the aluminum-plastic film is avoided.

[0003] In order to further enhance the above-mentioned improvement effect, the method of increasing the area of ​​hot melt adhesive is usually adopted. Although this method can improve the battery's anti-drop performance to a certain extent, it will increase the amount of hot melt adhesive used, thereby increasing the manufacturing cost of lithium-ion batteries. In addition, since the surface area of ​​lithium-ion batteries is relatively fixed, in other words, the area that can be used to apply hot melt adhesive is also limited, and it will also increase the thickness of the battery, thereby affecting the energy density of the lithium-ion battery.

[0004] Based on this, it is urgent to invent a hot melt adhesive, a battery cell, a battery and an electrochemical device to solve the above-mentioned technical problems. Utility Model Content

[0005] The technical problem to be solved by the utility model is how to improve the anti-drop performance of the battery without increasing the thickness of the battery. In view of the above problems, a hot melt adhesive, a battery cell, a battery and an electrochemical device are provided.

[0006] The technical solution of the utility model to solve the above technical problems is to provide a hot melt adhesive for bonding the packaging shell to the surface of the bare battery cell, including:

[0007] An adhesive layer having at least a single layer and used to increase the friction between the packaging shell and the bare battery core, wherein the adhesive layer comprises a plurality of protrusions;

[0008] A substrate layer is attached to the adhesive layer.

[0009] Specifically, each of the protrusions extends outward from the surface of the substrate layer, and a plurality of the protrusions are evenly and spacedly distributed on the substrate layer.

[0010] More specifically, the height of each protrusion is 10 um to 20 um, and the sum of the cross-sectional areas of a plurality of protrusions accounts for 60% to 80% of the surface area of ​​the substrate layer.

[0011] Furthermore, the number of the bonding layer is a single layer.

[0012] Furthermore, the number of the adhesive layers is two, and the substrate layer is attached between the two adhesive layers.

[0013] Preferably, the cross-sectional shape of the protrusion is circular, square or diamond-shaped.

[0014] More preferably, two layers of release paper are further included, and the two layers of release paper are respectively adhered to the surfaces of the two layers of adhesive layers.

[0015] In one specific embodiment, the utility model provides a battery cell, including a bare battery cell, a packaging shell and the hot melt adhesive as described above, and the packaging shell is bonded to the bare battery cell by the hot melt adhesive.

[0016] In one specific embodiment, the utility model provides a battery, comprising a plurality of battery cells as described above.

[0017] In one specific embodiment, the present invention provides an electrochemical device comprising a plurality of batteries as described above.

[0018] The beneficial effect of the utility model is that the roughness of the hot melt adhesive is increased by attaching a plurality of protrusions on the adhesive layer to the base material layer, thereby improving the anti-drop performance of the battery without increasing the thickness of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the hot melt adhesive of the utility model;

[0020] Figure 2 This is one of the implementation methods of the hot melt adhesive of the utility model;

[0021] Figure 3 This is the second implementation method of the hot melt adhesive of the utility model;

[0022] Figure 4 This is the third implementation method of the hot melt adhesive of the utility model.

[0023] Reference numerals:

[0024] 1-hot melt adhesive; 10-adhesive layer; 100-convex portion; 101-concave portion; 11-base material layer; 12-release paper. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0026] Implementation Method 1

[0027] like Figure 1 As shown, the utility model provides a hot melt adhesive 1 for bonding the packaging shell to the surface of the bare battery cell, that is, for achieving bonding between the bare battery cell and the packaging shell. The hot melt adhesive 1 includes at least a single layer of adhesive layer 10 for increasing the friction between the packaging shell and the bare battery cell. Obviously, in order to increase the friction between the packaging shell and the bare battery cell, each adhesive layer 10 includes a plurality of protrusions 100. It should be noted that in other specific embodiments, the number of hot melt adhesives 1 is not limited. And in order to protect the adhesive layer 10, the hot melt adhesive 1 also includes a substrate layer 11 attached to the adhesive layer 10.

[0028] The manufacturing method of the bonding layer 10 is described in detail below: the prepared colloidal slurry is directly coated or sprayed on the substrate layer 11 according to the required area, and the bonding layer 10 is formed after cooling.

[0029] Implementation Method 2

[0030] The difference between this embodiment and embodiment 1 is that: in order to facilitate processing and manufacturing, each protrusion 100 extends outward from the surface of one side of the substrate layer 11, that is, the protrusion 100 forms an inner recess 101 relative to the surface of the substrate layer 11, and the friction between the packaging shell and the bare battery cell is increased by the protrusion 100 and the inner recess 101 (the surface of the substrate layer 11 is an uneven surface). And in order to enhance the adhesion of the hot melt adhesive 1, a number of protrusions 100 are evenly and spaced on the substrate layer 11. In contrast, the number of inner recesses 101 is also several, and a number of inner recesses 101 are also evenly and spaced on the substrate layer 11. It can be understood that a number of protrusions 100 and a number of inner recesses 101 are also spaced apart. The other parts of this embodiment are the same as those in embodiment 1 and will not be described here.

[0031] Implementation 3

[0032] The difference between this embodiment and embodiment 1 is that in order to ensure that the adhesion of the lithium-ion battery with conventional parameters (here referring to weight) is optimal, the height of each protrusion 100 is 10um~20um, and the sum of the cross-sectional areas of several protrusions 100 accounts for 60%~80% of the surface area of ​​the substrate layer 11.

[0033] Test of battery drop resistance in implementation mode 3:

[0034] 1. The hot melt adhesive 1 of the utility model was pasted on the surface of bare cells of different weights, and the bare cells pasted with hot melt adhesive were encapsulated in aluminum plastic film (experimental group). At the same time, some batteries pasted with conventional hot melt adhesive and with corresponding weights were taken as the control group;

[0035] 2. Subject the above-mentioned batteries (experimental group and control group) to a drop test under the same conditions. The aforementioned test method is: install the battery in a drop fixture and perform a directional drop at a height of 1.5m, wherein the drop direction is in the order of “front-side-bottom-top-left-right-upper left corner-upper right corner-lower left corner-lower right corner”, and each side / corner falls in turn as 1 round, for a total of 10 rounds. After each drop, it is necessary to check whether the battery is damaged or leaking, and keep records. The test results are summarized as follows:

[0036] Table 1:

[0037]

[0038] Conclusion: When the battery using the hot melt adhesive 1 of the utility model is dropped from a height of 1.5 m, the outer packaging is not damaged and there is no abnormality inside (no leakage).

[0039] The other parts of this embodiment are the same as those of embodiment 1 and will not be described in detail here.

[0040] Implementation 4

[0041] The difference between this embodiment and embodiment 1 is that in order to reduce the thickness of the hot melt adhesive and thus avoid affecting the energy density of the battery due to the increase in the thickness of the hot melt adhesive, the number of the adhesive layer 10 is a single layer. Of course, in other specific embodiments, the number of adhesive layers 10 is not limited. It should be noted that, at this time, a substrate layer 11 with an adhesive effect is required. The other parts of this embodiment are the same as those of embodiment 1 and are not described in detail here.

[0042] Implementation method 5

[0043] The difference between this embodiment and embodiment 1 is that, in order to ensure the firmness of hot melt adhesive bonding, there are two adhesive layers 10, and the base material layer 11 is attached between the two adhesive layers 10. The other parts of this embodiment are the same as those of embodiment 1, and will not be described in detail here.

[0044] Implementation 6

[0045] The difference between this embodiment and embodiment 1 is that: Figure 2 , Figure 3 and Figure 4 In order to facilitate processing and manufacturing, the cross-sectional shape of the protrusion 100 can be circular, square or diamond. Of course, in other specific embodiments, the cross-sectional shape of the protrusion 100 can also be other shapes, for example, the cross-sectional shape of the protrusion 100 can be an ellipse. The other parts of this embodiment are the same as those of embodiment 1, and will not be repeated here.

[0046] Implementation 7

[0047] The difference between this embodiment and embodiment 5 is that: in order to facilitate the packaging, sale and use of the hot melt adhesive 1, the hot melt adhesive 1 further includes at least one layer of release paper 12. In this specific embodiment, the number of release paper 12 is one layer, and the release paper 13 is pasted on the surface of any adhesive layer 10; in other specific embodiments, the number of release paper 12 is two layers, and the two layers of release paper 12 are respectively pasted on the surfaces of the two adhesive layers 10. The other parts of this embodiment are the same as those of embodiment 5, and will not be repeated here.

[0048] Implementation 8

[0049] The difference between this embodiment and the above embodiment is that the present invention further provides a battery cell, including a bare cell, a packaging shell and the hot melt adhesive 1 as described above, and the packaging shell is bonded to the bare cell by the hot melt adhesive 1. The other parts of this embodiment are the same as the above embodiment, and will not be described here.

[0050] Implementation method 9

[0051] The difference between this embodiment and the above embodiment is that: the present invention further provides a battery, including the battery cell as described above. The other parts of this embodiment are the same as the above embodiment, and will not be described here.

[0052] Embodiment 10

[0053] The difference between this embodiment and the above embodiment is that the present invention further provides an electrochemical device, including the battery as described above. The other parts of this embodiment are the same as the above embodiment, and will not be described in detail here.

[0054] The above is only a preferred specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A hot melt adhesive, characterized in that: Used to bond the packaging shell to the bare cell surface, including: An adhesive layer having at least a single layer and used to increase the friction between the packaging shell and the bare battery core, wherein the adhesive layer comprises a plurality of protrusions; A substrate layer is attached to the adhesive layer.

2. The hot melt adhesive according to claim 1, characterized in that: The height of each protrusion is 10um to 20um, and the sum of the cross-sectional areas of a plurality of protrusions accounts for 60% to 80% of the surface area of ​​the substrate layer.

3. The hot melt adhesive according to claim 1, characterized in that: Each of the protrusions extends outward from the surface of the substrate layer, and a plurality of the protrusions are evenly and spacedly distributed on the substrate layer.

4. The hot melt adhesive according to claim 1, characterized in that: The number of the adhesive layer is a single layer.

5. The hot melt adhesive according to claim 1, characterized in that: The number of the adhesive layers is two, and the substrate layer is attached between the two adhesive layers.

6. The hot melt adhesive according to claim 1, characterized in that: The cross-sectional shape of the protrusion is circular, square or diamond.

7. The hot melt adhesive according to claim 5, characterized in that: It also includes two layers of release paper, and the two layers of release paper are respectively adhered to the surfaces of the two layers of adhesive layers.

8. A battery cell, characterized in that: It comprises a bare battery core, a packaging shell and the hot melt adhesive as described in any one of claims 1 to 7, and the packaging shell is bonded to the bare battery core by the hot melt adhesive.

9. A battery, characterized in that: The invention comprises a plurality of battery cells as claimed in claim 8.

10. An electrochemical device, characterized in that: Comprising the battery as claimed in claim 9.

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