WO2022160269A1 - Electrochemical apparatus and electronic device - Google Patents

Abstract

The present application relates to an electrochemical apparatus and an electronic device. The electrochemical apparatus comprises: a housing; an electrode assembly, which is at least partially located in the housing; and an insulation tape, which is located between the housing and the electrode assembly. In addition, the insulation tape comprises a first surface bonded with the electrode assembly and a second surface bonded with the housing. The insulation tape satisfies at least one of the following conditions: a) the first surface comprises a first bonding region having a bonding strength of P1 and a second bonding region having a bonding strength of P2, 0.2×P1≤P2≤0.9×P1; and b) the second surface comprises a third bonding region having a bonding strength of P3 and a fourth bonding region having a bonding strength of P4, 0.2×P3≤P4≤0.9×P3. The described insulation tape can increase the service life and reliability of the electrochemical apparatus, and can reduce the risk of the insulation tape tearing the aluminum foil of the electrode assembly during dropping and prevent short-circuiting from occurring inside of the electrode assembly.

Description

Electrochemical devices and electronic equipment technical field

The present application relates to the technical field of energy storage devices, and in particular, to an electrochemical device and an electronic device.

Background technique

With the development of electronic equipment, the battery of the electronic equipment is required to have a larger capacity to meet the battery life requirements of the electronic equipment. A battery of an electronic device generally includes a case and an electrode assembly inside the case, and the case protects the electrode assembly. The housing and the electrode assembly can be bonded by insulating tape. When the electronic device falls, the insulating tape may tear the electrode assembly, resulting in an internal short circuit of the electrode assembly. When the insulating tape is poorly bonded, the top seal may be broken. and other risks, affecting the safety of electronic equipment.

SUMMARY OF THE INVENTION

The present application provides an electrochemical device and electronic equipment, which can improve the connection reliability between the electrode assembly and the casing, reduce the risk of tearing the aluminum foil of the electrode assembly, and improve the drop resistance.

A first aspect of the present application provides an electrochemical device, the electrochemical device comprising: a casing, an electrode assembly and an insulating tape, at least a part of the electrode assembly is located in the casing; the insulating tape is located between the casing and the electrode assembly, and insulating tape The adhesive tape includes a first surface bonded with the electrode assembly and a second surface bonded with the casing; wherein, the first surface includes a first bonding area with a bonding strength of P1 and a second bonding area with a bonding strength of P2 area, 0.2×P1≤P2≤0.9×P1.

A second aspect of the present application provides an electrochemical device, the electrochemical device comprising: a casing, an electrode assembly and an insulating tape, at least part of the electrode assembly is located in the casing; the insulating tape is located between the casing and the electrode assembly, and the insulating tape is It includes a first surface bonded with the electrode assembly and a second surface bonded with the casing; wherein, the second surface includes a third bonding area with a bonding strength of P3 and a fourth bonding area with a bonding strength of P4 , 0.2×P3≤P4≤0.9×P3.

A third aspect of the present application provides an electrochemical device, the electrochemical device comprising: a casing, an electrode assembly and an insulating tape, at least part of the electrode assembly is located in the casing; the insulating tape is located between the casing and the electrode assembly, and insulating The adhesive tape includes a first surface bonded with the electrode assembly and a second surface bonded with the casing; wherein, the first surface includes a first bonding area with a bonding strength of P1 and a second bonding area with a bonding strength of P2 area, 0.2×P1≤P2≤0.9×P1; the second surface includes a third bonding area with a bonding strength of P3 and a fourth bonding area with a bonding strength of P4, 0.2×P3≤P4≤0.9×P3.

In one possible design, 0.3×P1≤P2≤0.9×P1.

In one possible design, 0.3×P3≤P4≤0.9×P3.

In a possible design, the second bonding area has a second inner edge and a second outer edge; the width of the first surface is W2, and the distance between the second inner edge and the second outer edge is h1, wherein, 0.05×W2≤h1≤0.4×W2. In another possible design, 0.05×W2≤h1≤0.35×W2.

In a possible design, the fourth bonding area has a fourth inner edge and a fourth outer edge; the width of the second surface is W3, and the distance between the fourth inner edge and the fourth outer edge is h2, wherein, 0.05×W3≤h2≤0.4×W3. In another possible design, 0.1×W3≤h2≤0.3×W3.

In a possible design, the area A1 of the first bonding area and the area B1 of the second bonding area satisfy: 0.05≤B1/(A1+B1)≤0.928. In another possible design, 0.1≤B1/(A1+B1)≤0.7.

In a possible design, the area A2 of the third bonding area and the area B2 of the fourth bonding area satisfy: 0.05≤B2/(A2+B2)≤0.928. In another possible design, 0.2≤B2/(A2+B2)≤0.6.

In a possible design, the second adhesive area is located on one side of the first adhesive area, or the second adhesive area is located on opposite sides of the first adhesive area, or the second adhesive area is located on the first adhesive area. around a bonding area.

In a possible design, the fourth adhesive area is located on one side of the third adhesive area, or the fourth adhesive area is located on opposite sides of the third adhesive area, or the fourth adhesive area is located on the third adhesive area. around the three bonding areas.

In a possible design, there is a gap between the first bonding area and the second bonding area.

In a possible design, there is a gap between the third bonding area and the fourth bonding area.

In a possible design, the first bonding area has a first outer edge, and the first outer edge coincides with the second inner edge.

In a possible design, the third bonding area has a third outer edge, and the third outer edge coincides with the fourth inner edge.

In a possible design, the orthographic projection of the third bonding area on the first surface coincides with the first bonding area.

In a possible design, the orthographic projection of the fourth bonding area on the first surface coincides with the second bonding area.

In a possible design, the electrode assembly has a third surface adhered to the insulating tape, and the length of the third surface is L1; the first surface has a first axis extending along the width direction of the electrochemical device, and the third surface has For the second axis extending along the width direction of the electrochemical device, the distance between the orthographic projection of the first axis on the third surface and the second axis is D, where D≤0.15×L1.

In a possible design, the electrode assembly has a third surface adhered to the insulating tape, the length of the third surface is W1; the first surface has a third axis extending along the length direction of the electrochemical device, and the third surface has For the fourth axis extending along the length direction of the electrochemical device, the distance between the orthographic projection of the third axis on the third surface and the fourth axis is E, E≤0.15×W1.

In a possible design, the length of the first surface is L2, and the width of the first surface is W2; wherein, 0.3×L1≤L2≤0.9×L1, 0.3×W1≤W2≤0.9×W1. In another possible design, 0.4×L1≤L2≤0.8×L1, 0.4×W1≤W2≤0.8×W1.

In a possible design, the shape of the first surface and/or the second surface is selected from any one of square, rectangle, trapezoid, octagon, circle, and ellipse.

A fourth aspect of the present application provides an electronic device comprising the electrochemical device described above.

When the casing of the electrochemical device is subjected to an external force (for example, the casing is subjected to an external force during a drop test), the external force can be transmitted from the casing to the second surface of the insulating tape, from the second surface to the first surface, and Transferred from the first surface to the electrode assembly, since the first surface has a first bonding area and a second bonding area, and/or the second surface has a third bonding area and a fourth bonding area, and the bonding strength The first bonding area with larger P1 can improve the connection reliability between the insulating tape and the electrode assembly, and/or the third bonding area with larger bonding strength P3 can improve the connection reliability between the insulating tape and the casing Therefore, the reliability of the connection between the casing and the electrode assembly is improved, the risk of the top seal breaking due to the movement of the electrode assembly when the electrochemical device is dropped, and the service life and reliability of the electrochemical device are improved.

At the same time, the second bonding area with smaller bonding strength P2 can release the adhesion with the electrode assembly when the electrochemical device is dropped, and/or the fourth bonding area with smaller bonding strength P4 is When the device is dropped, the adhesion between the device and the casing can be released, so that the energy transferred to the electrode assembly during the drop process can be absorbed, thereby reducing the risk that the aluminum foil of the electrode assembly will be torn by the insulating tape during the drop process, preventing short circuit inside the electrode assembly. , and further improve the service life and reliability of electrochemical devices.

It is to be understood that the foregoing general description and the following detailed description are exemplary only and do not limit the application.

Description of drawings

1 is a schematic diagram of the connection structure of a casing, an electrode assembly, and an insulating tape in a first specific embodiment of the application;

2 is a schematic diagram of the connection structure of the casing, the electrode assembly, and the insulating tape in the second specific embodiment of the application;

3 is a schematic structural diagram of the projection of the insulating tape on the third surface in the third specific embodiment of the present application;

4 is a schematic diagram of the connection structure of the casing, the electrode assembly, and the insulating tape in the fourth specific embodiment of the application;

5 is a schematic diagram of the connection structure of the casing, the electrode assembly, and the insulating tape in the fifth specific embodiment of the application;

6 is a schematic structural diagram of the projection of the insulating tape on the third surface in the sixth specific embodiment of the application;

7 is a schematic diagram of the connection structure of the casing, the electrode assembly, and the insulating tape in the seventh specific embodiment of the application;

8 is a schematic diagram of the connection structure of the casing, the electrode assembly, and the insulating tape in the eighth specific embodiment of the application;

9 is a schematic diagram of the connection structure of the housing, the electrode assembly, and the insulating tape in the ninth specific embodiment of the application;

10 is a side view of the electrochemical device provided by the application;

FIG. 11 is a schematic structural diagram of the electrochemical device provided by the present application.

Reference number:

1 - shell;

2- electrode assembly;

21 - the third surface;

211 - the second axis;

212 - the fourth axis;

3- Insulation tape;

31 - the first surface;

311 - the first bonding area;

311a - first outer edge;

312 - the second bonding area;

312a - second outer edge;

312b - second inner edge;

313 - first axis;

314 - third axis;

32 - the second surface;

321 - the third bonding area;

321a - third outer edge;

322 - the fourth bonding area;

322a - the fourth outer edge;

322b - Fourth inner edge;

33 - the first glue material;

34- The second glue material;

35 - Substrate.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description serve to explain the principles of the application.

Detailed ways

In order to better understand the technical solutions of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

It should be clear that the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. All other embodiments obtained based on the embodiments in this application fall within the protection scope of this application.

The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. As used in the embodiments of this application and the appended claims, the singular forms "a," "the," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

It should be understood that the term "and/or" used in this document is only an association relationship to describe the associated objects, indicating that there may be three kinds of relationships, for example, A and/or B, which may indicate that A exists alone, and A and B exist at the same time. B, there are three cases of B alone. In addition, the character "/" in this document generally indicates that the related objects are an "or" relationship.

It should be noted that the directional words such as "up", "down", "left", and "right" described in the embodiments of the present application are described from the angles shown in the drawings, and should not be construed as implementing the present application. Example limitation. Also, in this context, it should also be understood that when an element is referred to as being "on" or "under" another element, it can not only be directly connected "on" or "under" the other element, but also Indirectly connected "on" or "under" another element through intervening elements.

The embodiments of the present application provide an electrochemical device. As shown in FIG. 1 to FIG. 2 , the electrochemical device includes a casing 1 and an electrode assembly 2 . The casing 1 has a accommodating cavity, and at least part of the electrode assembly 2 is located in the accommodating cavity. Inside, the case 1 is used to protect the electrode assembly 2 . Wherein, the electrode assembly 2 may include a first pole piece, a second pole piece and a separator. In the first pole piece and the second pole piece, one is the positive pole, the other is the negative pole, the separator is used to separate the first pole piece and the second pole piece, and the separator can be supported by a thermoplastic resin, such as polyethylene Or polypropylene, the separator is used to insulate the first and second pole pieces.

During the drop test of the electrochemical device, risks such as top seal breaking and tearing of the aluminum foil of the electrode assembly 2 are likely to occur, thereby causing a short circuit in the electrode assembly 2, resulting in damage to the electrochemical device. In order to solve this technical problem, as shown in FIG. 1 to FIG. 3 , the electrochemical device further includes an insulating tape 3 , the insulating tape 3 is located between the casing 1 and the electrode assembly 2 , and the insulating tape 3 includes and the electrode assembly 2 . The first surface 31 to be bonded and the second surface 32 to be bonded to the casing 1, that is, the electrode assembly 2 is connected to the casing 1 through the insulating tape 3, thereby reducing the amount of the electrode assembly 2 in the casing 1 during the operation of the electrochemical device. In addition, the insulating tape 3 can also prevent the short circuit between the electrode assembly 2 and the casing 1, so that the electrochemical device can work normally.

When the bonding strength of the insulating tape 3 is too small, during the drop process of the electrochemical device, under the action of external force, the bonding reliability between the insulating tape 3 and the electrode assembly 2 decreases, causing the electrode assembly 2 to move, thereby causing The electrochemical device fails; when the bonding strength of the insulating tape 3 is too large, the insulating tape 3 exerts a large tensile force on the electrode assembly 2 during the fall of the electrochemical device, thereby causing the aluminum foil of the electrode assembly 2 to tear, resulting in The electrochemical device is short-circuited internally and fails.

In order to solve this technical problem, in this embodiment, as shown in FIG. 1 and FIG. 2 , the first surface 31 includes a first bonding area 311 with a bonding strength of P1 and a second bonding area with a bonding strength of P2 312, wherein, P1>P2.

When the casing 1 of the electrochemical device is subjected to an external force (for example, the casing 1 is subjected to an external force during a drop test), the external force can be transmitted from the casing 1 to the second surface 32 of the insulating tape 3 and transmitted from the second surface 32 to the first surface 31, and from the first surface 31 to the electrode assembly 2, since the first surface 31 has the first bonding area 311 and the second bonding area 312, the first bonding strength P1 is larger. The area 311 can improve the connection reliability between the insulating tape 3 and the electrode assembly 2, thereby reducing the risk of the top seal breaking due to the movement of the electrode assembly 2 when the electrochemical device is dropped, and improving the service life and reliability of the electrochemical device; The second bonding area 312 with a smaller bonding strength P2 can release the adhesion with the electrode assembly 2 when the electrochemical device is dropped, so as to absorb the energy transmitted to the electrode assembly 2 during the drop process, thereby reducing the drop process. The risk of tearing the aluminum foil of the electrode assembly 2 by the insulating tape 3 prevents a short circuit inside the electrode assembly 2 and further improves the service life and reliability of the electrochemical device.

Specifically, as shown in FIG. 1, the first bonding area 311 has a first outer edge 311a, and the second bonding area 312 is located on one side of the first bonding area 311, or, as shown in FIG. The two bonding areas 312 are located on opposite sides of the first bonding area 311 , or, as shown in FIG. 3 , the second bonding areas 312 are located around the first bonding area 311 .

During the fall of the electrochemical device, under the action of the external force transmitted by the insulating tape 3, the aluminum foil near the outer edge of the electrode assembly 2 is easily torn. In this embodiment, in the first surface 31 , the second bonding area 312 with the smaller bonding strength P2 is located outside the first bonding area 311 with the larger bonding strength P1 , so the electrochemical device is in the process of dropping. Under the action of external force, the bonding between the second bonding area 312 located outside the first bonding area 311 and the electrode assembly 2 can be broken, thereby reducing the electrode assembly bonded to the second bonding area 312 The risk of tearing of the aluminum foil of 2 (near the outer edge of the electrode assembly 2) increases the service life and reliability of the electrochemical device. At the same time, when the first bonding area 311 with the larger bonding strength P1 is located inside the second bonding area 312, the bond disconnection between the first bonding area 311 and the electrode assembly 2 can be reduced under the action of external force risks of.

In the above embodiments, as shown in FIGS. 1 to 2 , the first bonding area 311 has a first outer edge 311a, and the second bonding area 312 has a second outer edge 312a and a second inner edge 312b; FIG. 3 As shown, the width of the first surface 31 is W2, and the distance between the second inner edge 312b and the second outer edge 312a is h1, where 0.05×W2≤h1≤0.4×W2. For example, h1 may specifically be 0.15×W2, 0.2×W2, 0.3×W2, 0.35×W2, and the like.

In this embodiment, when h1 is too large, it means that the distance between the second inner edge 312b and the second outer edge 312a is that h1 is too large, that is, the size of the second bonding area 312 is too large, and the first bonding area 311 The size of the insulating tape 3 is too small, resulting in low reliability of the connection between the insulating tape 3 and the electrode assembly 2. Under the action of the external force transmitted by the insulating tape 3, the bonding between the first bonding area 311 and the electrode assembly 2 It is easy to disconnect, resulting in a low service life of the electrochemical device; when h1 is too small, it means that the distance between the second inner edge 312b and the second outer edge 312a is too small, that is, the size of the second bonding area 312 If it is too small, the size of the first bonding area 311 is too large. Under the action of external force, the bonding area between the insulating tape 3 and the electrode assembly 2 that can be broken is small, resulting in the second bonding area. 312 cannot effectively absorb the pulling force of the insulating tape 3 on the electrode assembly 2 , resulting in a high risk of tearing the aluminum foil of the electrode assembly 2 under the action of the insulating tape 3 . Therefore, when 0.05×W2≤h1≤0.4×W2, the distance h1 between the second inner edge 312b and the second outer edge 312a is moderate, so that the insulating tape 3 and the electrode assembly 2 have high connection reliability and can reduce the risk of tearing the aluminum foil of the electrode assembly 2 by the insulating tape 3 .

In the above embodiments, the bonding strength P1 of the first bonding area 311 and the bonding strength P2 of the second bonding area 312 satisfy: 0.2×P1≤P2≤0.9×P1. Wherein, P2 may specifically be 0.3×P1, 0.5×P1, 0.6×P1, 0.8×P1, 0.9×P1, and the like.

In this embodiment, when the ratio between P2 and P1 is too large, the bonding strength P2 of the second bonding area 312 is too large compared with the bonding strength P1 of the first bonding area 311 , resulting in During the drop process, the bonding between the second bonding area 312 and the electrode assembly 2 cannot be broken, so that the tensile force transmitted by the insulating tape 3 to the electrode assembly 2 cannot be effectively absorbed, resulting in the insulating tape 3 tearing the aluminum foil of the electrode assembly 2. The risk of cracking is high; if the ratio between P2 and P1 is too small, the bonding strength P1 of the first bonding area 311 is too small compared with the bonding strength P2 of the second bonding area 312, resulting in The bonding reliability between the electrode assemblies 2 is low, thereby causing the electrode assemblies 2 to move within the casing 1 . Therefore, when 0.2×P1≤P2≤0.9×P1, the bonding strength P1 of the first bonding area 311 and the bonding strength P2 of the second bonding area 312 are moderate, which can improve the gap between the insulating tape 3 and the electrode assembly 2 The connection reliability is improved, and the risk of tearing the aluminum foil of the electrode assembly 2 by the insulating tape 3 can be reduced.

Wherein, the bonding strength of the insulating tape 3 is related to factors such as the quality and size of the electrochemical device, and it is necessary to satisfy the requirement that the electrochemical device does not move relatively between the insulating tape 3 and the electrode assembly 2 during the drop process, and the insulating tape 3 3 will not tear the aluminum foil of the electrode assembly 2. Generally, the bonding strength P1 of the first bonding area 311 is in the range of 2 MPa to 20 MPa; the bonding strength P3 of the third bonding area 321 is in the range of 2 MPa to 20 MPa.

In the above embodiments, as shown in FIGS. 1 and 2 , in the insulating tape 3, the area A1 of the first bonding area 311 and the area B1 of the second bonding area 312 on the first surface 31 satisfy:

0.05≤B1/(A1+B1)≤0.928. In a specific embodiment, the area A1 of the first bonding area 311 and the area B1 of the second bonding area 312 satisfy: 0.1≤B1/(A1+B1)≤0.7. For example, the B1/(A1+B1) may specifically be 0.05, 0.1, 0.3, 0.5, 0.8, 0.9 and the like.

Taking the lithium-ion battery whose maximum projection surface is a rectangle as an example, the drop test is carried out to compare the drop passing rate. Among them, group 1 has the structure of FIG. 1 , and there is a second bonding area 312 on one side of the first bonding area 311 ; Group 2 has the structure of FIG. 2, and it has the second bonding area 312 on opposite sides of the first bonding area 311; Group 3 and group 4 have the structure of FIG. 3, and it has the first bonding area 311 around Second bonding area 312; set the number of repeated experiments of lithium ion batteries at each position to 20 times, and the pass rate is required to be not less than 80% (that is, at least 16 lithium ion batteries will not fail when dropped) to be qualified, and the drop condition: group 1 is a single side drop, group 2 is two opposite side drops, group 3 and group 4 are six sides and four corners. The selected dimensions of the insulating tape 3 of the rectangular lithium-ion battery are: the length L2 of the first surface 31 is 50 mm, and the width W2 of the first surface 31 is 40 mm. The test results are shown in the following table:

According to the test results in the above table, it can be seen that after setting the insulating tape 3 satisfying the following requirements: 0.05×W2≤h1≤0.4×W2, 0.2×P1≤P2≤0.9×P1, the electrochemical device has a higher performance in the drop test. The pass rate is higher (≥90%) when 0.05×W2≤h1≤0.35×W2, 0.3×P1≤P2≤0.9×P1.

In a specific embodiment, after setting the insulating tape 3 satisfying the following: 0.05×W2≤h1≤0.4×W2, 0.2×P1≤P2≤0.9×P1, 0.05≤B1/(A1+B1)≤0.928, The electrochemical device has a high pass rate in the drop test, and when, 0.05×W2≤h1≤0.35×W2, 0.3×P1≤P2≤0.9×P1, 0.1≤B1/(A1+B1)≤0.7 , the pass rate is higher (≥90%).

More specifically, as shown in FIG. 9 , there is a gap between the first adhesive area 311 and the second adhesive area 312 of the first surface 31 of the insulating tape 3 , that is, the insulating tape 3 is a split structure, and the first adhesive The contact area 311 and the second bonding area 312 are respectively located on different adhesive materials.

In this embodiment, when there is a gap between the first adhesive area 311 and the second adhesive area 312, the external force acting on the insulating tape 3 can be prevented from being applied between the first adhesive area 311 and the second adhesive area 312. transmission, thereby reducing the risk of disconnection of the bonding between the first bonding area 311 and the electrode assembly 2 caused by the external force transmitted to the first bonding area 311, and improving the connection reliability between the insulating tape 3 and the electrode assembly 2, Thereby, the reliability and service life of the electrochemical device are improved. At the same time, when the first bonding area 311 and the second bonding area 312 are located in different adhesive materials, it is also easy to realize that the two have different bonding strengths, thereby reducing the processing difficulty of the insulating tape 3 .

When the bonding strength between the surface of the insulating tape 3 and the casing is relatively high, the pulling force exerted by the casing 1 on the insulating tape 3 can be transmitted to the electrode assembly 2 during the falling process of the electrochemical device, thereby causing The aluminum foil of the electrode assembly 2 was torn, resulting in an internal short circuit and failure of the electrochemical device.

In order to solve this technical problem, in this embodiment, as shown in FIGS. 4 and 5 , the second surface 32 includes a third bonding area 321 with a bonding strength of P3 and a fourth bonding area 322 with a bonding strength of P4 , where P3>P4.

When the casing 1 of the electrochemical device is subjected to an external force (for example, the casing 1 is subjected to an external force during a drop test), the external force can be transmitted from the casing 1 to the second surface 32 of the insulating tape 3 and transmitted from the second surface 32 to the first surface 31 and from the first surface 31 to the electrode assembly 2 . Since the second surface 32 has the third bonding area 321 and the fourth bonding area 322, the third bonding area 321 with the larger bonding strength P3 can improve the connection reliability between the insulating tape 3 and the housing 1, Thereby, the connection reliability of the casing 1 and the electrode assembly 2 is improved, the risk of the top seal breaking due to the movement of the electrode assembly 2 when the electrochemical device is dropped is reduced, and the service life and reliability of the electrochemical device are improved; The small fourth bonding area 322 can release the adhesion between the electrochemical device and the casing 1 when the electrochemical device is dropped, so as to absorb the energy transferred to the electrode assembly 2 during the drop process, thereby reducing the insulation tape 3 during the drop process. The risk of tearing the aluminum foil of the assembly 2 prevents a short circuit inside the electrode assembly 2, and further improves the service life and reliability of the electrochemical device.

Specifically, as shown in FIG. 4, the third bonding area 321 has a third outer edge 321a, and the fourth bonding area 322 is located on one side of the third bonding area 321, or, as shown in FIG. The contact areas 322 are located on opposite sides of the third adhesive area 321 , or, as shown in FIG. 6 , the fourth adhesive area 322 is located around the third adhesive area 321 .

During the fall of the electrochemical device, under the action of the external force transmitted by the insulating tape 3, the aluminum foil near the outer edge of the electrode assembly 2 is easily torn. In this embodiment, in the second surface 32, the fourth bonding area 322 with the smaller bonding strength P4 is located outside the third bonding area 321 with the larger bonding strength P3, therefore, the electrochemical device is in the process of dropping. , under the action of external force, the bonding between the fourth bonding area 322 located outside the third bonding area 321 and the casing 1 can be broken, thereby reducing the transmission of the fourth bonding area 322 to the electrode assembly 2 . The magnitude of the pulling force reduces the risk of tearing of the aluminum foil of the electrode assembly 2 (near the outer edge of the electrode assembly 2 ), and improves the service life and reliability of the electrochemical device. At the same time, when the third bonding area 321 with the larger bonding strength P3 is located inside the fourth bonding area 322, it can reduce the bonding disconnection between the third bonding area 321 and the casing 1 under the action of external force risks of.

Wherein, the bonding strength P3 of the third bonding area 321 and the bonding strength P4 of the fourth bonding area 322 satisfy: 0.2×P3≤P4≤0.9×P3. Wherein, P4 may specifically be 0.3×P3, 0.5×P3, 0.6×P3, 0.8×P3, 0.9×P3, and the like.

In this embodiment, when the ratio between P4 and P3 is too large, the bonding strength P4 of the fourth bonding region 322 is too large compared with the bonding strength P3 of the third bonding region 321 , which leads to During the drop process, the bonding between the fourth bonding area 322 and the electrode assembly 2 cannot be broken, so that the tensile force transmitted by the insulating tape 3 to the electrode assembly 2 cannot be effectively absorbed, resulting in the insulating tape 3 tearing the aluminum foil of the electrode assembly 2. The risk of cracking is high; if the ratio between P4 and P3 is too small, the bonding strength P3 of the third bonding area 321 is too small compared with the bonding strength P4 of the fourth bonding area 322, resulting in The bonding reliability between the electrode assemblies 2 is low, thereby causing the electrode assemblies 2 to move within the casing 1 . Therefore, when 0.2×P3≤P4≤0.9×P3, the bonding strength P3 of the third bonding area 321 and the bonding strength P4 of the fourth bonding area 322 are moderate, which can improve the gap between the insulating tape 3 and the housing 1 The connection reliability is improved, and the risk of tearing the aluminum foil of the electrode assembly 2 by the insulating tape 3 can be reduced.

The bonding strength of the insulating tape 3 is related to factors such as the quality and size of the electrochemical device, and it is necessary to satisfy the requirement that the electrochemical device does not move relatively between the shell 1 and the electrode assembly 2 during the drop process, and the insulating tape 3 3 will not tear the aluminum foil of the electrode assembly 2.

In the above embodiments, as shown in FIGS. 4 to 6 , the third bonding area 321 has a third outer edge 321a, and the fourth bonding area 322 has a fourth outer edge 322a and a fourth inner edge 322b; FIG. 6 As shown, the width of the second surface 32 is W3, and the distance between the fourth inner edge 322b and the fourth outer edge 322a is h2, where 0.05×W3≤h2≤0.4×W3. For example, h2 may specifically be 0.15×W3, 0.2×W3, 0.3×W3, or the like.

In the above embodiments, as shown in FIGS. 4 to 6 , in the insulating tape 3, the area A2 of the third bonding area 321 and the area B2 of the fourth bonding area 322 on the second surface 32 satisfy:

0.05≤B2/(A2+B2)≤0.928. In a specific embodiment, the area A2 of the third bonding area 321 of the second surface 32 and the area B2 of the fourth bonding area 322 satisfy: 0.2≤B2/(A2+B2)≤0.6. For example, the B2/(A2+B2) may specifically be 0.3, 0.5, 0.6, or the like.

Taking the lithium-ion battery with the largest projection surface as a rectangle as an example, the drop test was carried out to compare the drop passing rate. Among them, group 5 had the structure shown in FIG. Contact area 322; group 6 has the structure shown in FIG. 5, and there are fourth bonding areas 322 on opposite sides of the third bonding area 321; group 7 and group 8 have the structure shown in FIG. There is a fourth bonding area 322 around the three bonding areas 321; the number of repeated experiments of the lithium ion battery at each position is set to 20 times, and the pass rate is required to be not less than 80% (that is, at least 16 lithium ion batteries do not fail when dropped ) is qualified, and the drop conditions are: group 5 is a single side drop, group 6 is a drop from two opposite sides, and groups 7 and 8 are six sides and four corners. The selected dimensions of the insulating tape 3 of the rectangular lithium ion battery are: the length L3 of the second surface 32 is 50 mm, and the width W3 of the second surface 32 is 40 mm. The test results are shown in the following table:

According to the test results in the above table, after setting the insulating tape 3 satisfying 0.05×W3≤h2≤0.4×W3 and 0.2×P3≤P4≤0.9×P3 of the present application, the electrochemical device has a higher performance in the drop test. The pass rate is higher (≥90%) when 0.1×W3≤h2≤0.3×W3, 0.3×P3≤P4≤0.9×P3.

In a possible design, after setting the insulating tape 3 that satisfies 0.05×W3≤h2≤0.4×W3, 0.2×P3≤P4≤0.9×P3, 0.05≤B2/(A2+B2)≤0.928 in the present application, so that Electrochemical devices have high pass rates in the drop test, and when 0.1×W3≤h2≤0.3×W3, 0.3×P3≤P4≤0.9×P3, 0.2≤B2/(A2+B2)≤0.6, The pass rate is higher (≥90%).

More specifically, as shown in FIG. 9, there is a gap between the third bonding area 321 and the fourth bonding area 322, that is, the insulating tape 3 is a split structure, and the third bonding area 321 and the fourth bonding area are 322 are located in different glue materials.

In this embodiment, when there is a gap between the third bonding area 321 and the fourth bonding area 322 , the external force acting on the insulating tape 3 can be prevented from being applied between the third bonding area 321 and the fourth bonding area 322 transmission, thereby reducing the risk of disconnection of the bonding between the third bonding area 321 and the casing 1 caused by the external force transmitted to the third bonding area 321, and improving the connection reliability between the insulating tape 3 and the casing 1, Thereby, the reliability and service life of the electrochemical device are improved. At the same time, when the third bonding area 321 and the fourth bonding area 322 are located in different adhesive materials, it is also easy to realize that the two have different bonding strengths, thereby reducing the processing difficulty of the insulating tape 3 .

In another specific embodiment, as shown in FIGS. 7 to 9 , in the insulating tape 3 , the first surface 31 includes a first bonding area 311 with a bonding strength of P1 and a second bonding area with a bonding strength of P2 The bonding area 312 and the second surface 32 include a second bonding area 321 with a bonding strength of P3 and a fourth bonding area 322 with a bonding strength of P4, wherein P1>P2, and P3>P4.

When the casing 1 of the electrochemical device is subjected to an external force (for example, the casing 1 is subjected to an external force during a drop test), the external force can be transmitted from the casing 1 to the second surface 32 of the insulating tape 3 and transmitted from the second surface 32 to the first surface 31, and from the first surface 31 to the electrode assembly 2, since the first surface 31 has a first bonding area 311 and a second bonding area 312, and the second surface 32 has a third bonding area 321 and The fourth bonding area 322, and the first bonding area 311 with the larger bonding strength P1 can improve the connection reliability between the insulating tape 3 and the electrode assembly 2, and the third bonding area with the larger bonding strength P3 321 can improve the connection reliability between the insulating tape 3 and the casing 1, thereby improving the connection reliability between the casing 1 and the electrode assembly 2, and reducing the top seal breaking due to the movement of the electrode assembly 2 when the electrochemical device is dropped. risk and improve the life and reliability of electrochemical devices.

At the same time, the second bonding area 312 with the smaller bonding strength P2 can be released from the adhesion with the electrode assembly 2 when the electrochemical device is dropped, and the fourth bonding area 322 with the smaller bonding strength P4 is in the electrochemical device. When the device is dropped, the adhesion between the device and the housing 1 can be released, so that the energy transmitted to the electrode assembly 2 during the drop process can be absorbed, thereby reducing the risk of tearing the aluminum foil of the electrode assembly 2 by the insulating tape 3 during the drop process, preventing the electrode assembly. A short circuit occurs inside the component 2, which further improves the service life and reliability of the electrochemical device.

In a specific embodiment, as shown in FIGS. 7 to 9 , the orthographic projection of the second bonding area 321 on the first surface 31 coincides with the first bonding area 311 , and the fourth bonding area 322 is on the first surface The orthographic projection of 31 coincides with the second bonding area 312 .

In this embodiment, as shown in FIG. 7 to FIG. 9 , in the insulating tape 3 , the second bonding area 312 with smaller bonding strength P2 corresponds to the fourth bonding area 322 with smaller bonding strength P4 , The first bonding area 311 with the larger bonding strength P1 corresponds to the third bonding area 321 with the larger bonding strength P3. When the electrochemical device is dropped, the external force is transmitted to the electrode assembly 2 through the casing 1 , the third bonding area 321 , and the first bonding area 311 . In the contact area, the bonding strength between the insulating component 3 and the casing 1 and the electrode assembly 2 is relatively high, and under the action of the external force, it is not easy to break the bonding between the electrode assembly 2 and the casing 1 . At the same time, the external force is transmitted to the electrode assembly 2 through the casing 1, the fourth bonding area 322 and the second bonding area 312. In the bonding area corresponding to the second bonding area 312 and the fourth bonding area 322, the insulating The bonding strength between the assembly 3 and the casing 1 and the electrode assembly 2 is relatively small. Under the action of this external force, the bonding between the insulating assembly 3 and the casing 1 and the electrode assembly 2 can be broken, thereby absorbing the transmission. The tensile force to the electrode assembly 2 prevents the aluminum foil of the electrode assembly 2 from being torn by the insulating tape 3 .

Taking a lithium-ion battery with a rectangular maximum projection surface as an example, a drop test was performed to compare the drop pass rate. Among them, group 9 had the structure shown in FIG. There are second bonding areas 312 and fourth bonding areas 322 on the same side of the Zone 312 and fourth bonding zone 322; group 11 has a structure in which there are second bonding zone 312 and fourth bonding zone 322 around the first bonding zone 311 and third bonding zone 321, respectively; set lithium ions The number of repeated experiments of the battery at each position is 20 times, and the pass rate is required to be no less than 80% (that is, at least 16 lithium-ion batteries do not fail when dropped) to be qualified. Drop conditions: group 9 is a single side drop, group 10 is a The two opposite sides are dropped, and the group 11 is six sides and four corners. The selected dimensions of the insulating tape 3 of the rectangular lithium ion battery are: the length L of the first surface 31 and the second surface 32 is 50 mm, and the width W of the first surface 31 and the second surface 32 is 40 mm. The test results are shown in the following table:

According to the test results in the above table, the first surface 31 and the second surface 32 are set to satisfy 0.05×W2≤h1≤0.4×W2, 0.05×W3≤h2≤0.4×W3, 0.2×P1≤P2≤0.9×P1, After the insulating tape 3 of 0.2×P3≤P4≤0.9×P3, the electrochemical device also has a high pass rate in the drop test.

Meanwhile, as shown in FIG. 3 , in the first surface 31 , the first outer edge 311 a of the first bonding area 311 is located in the area enclosed by the second outer edge 312 a of the second bonding area 312 , as shown in FIG. 6 . As shown, in the second surface 32 , the third outer edge 321 a of the third bonding area 321 is located in the area enclosed by the fourth outer edge 322 a of the fourth bonding area 322 .

In the above embodiments, as shown in FIG. 10 , the electrode assembly 2 has a third surface 21 bonded to the insulating tape 3, and the length of the third surface 21 is L1; and in the insulating tape 3, the first surface 31 has A first axis 313 extending in the width direction of the electrochemical device, the third surface 21 having a second axis 211 extending in the width direction of the electrochemical device, wherein the first surface 31 relative to the length direction of the electrochemical device The first axis 313 is symmetrical, and the third surface 21 is symmetrical with respect to the second axis 211 . The distance between the orthographic projection of the first axis 313 on the bonding surface 21 and the second axis 211 is D, where D may specifically be 0, or, according to the actual situation, the distance between D and L1 may also satisfy D≤ 0.15×L1. For example, D may be 0.05×L1, 0.06×L1, 0.1×L1, or the like. More specifically, as shown in FIG. 10 , the first surface 31 has a third axis 314 extending along the length of the electrochemical device, the third surface 21 has a fourth axis 212 extending along the length of the electrochemical device, and at In the embodiment shown in FIG. 6 , along the width direction of the electrochemical device, the first surface 31 is symmetrical with respect to the third axis 314 , and the third surface 21 is symmetrical with respect to the fourth axis 212 . The distance between the orthographic projection of the third axis 314 on the third surface 21 and the fourth axis 212 is E, where E may specifically be 0, or, according to the actual situation, the relationship between E and W1 may also satisfy E≤ 0.15×W1.

In this embodiment, the weight of the electrode assembly 2 is not uniform everywhere, and the connection reliability between the insulating tape 3 and the electrode assembly 2 is affected by the gravity of the electrode assembly 2. Therefore, when the weight of the electrode assembly 2 is not uniform , the influence of the gravity of the electrode assembly 2 on the connection reliability between the insulating tape 3 and the electrode assembly 2 can be reduced by changing the position of the insulating tape 3 on the third surface 21 .

In the above embodiments, as shown in FIG. 10 , the electrode assembly 2 has a third surface 21 that is bonded to the insulating tape 3 . The length of the third surface 21 is L1 and the width is W1; the insulating tape 3 is used for bonding with The length of the first surface 31 to which the electrode assembly 2 is bonded is L2 and the width is W2; wherein, 0.4×L1≤L2≤0.8×L1, and 0.4×W1≤W2≤0.8×W1. For example, L2 can be 0.4×L1, 0.5×L1, 0.7×L1, 0.8×L1, etc., and W2 can be 0.4×W1, 0.6×W1, 0.7×W1, 0.8×W1, and the like.

Among them, the relationship between L1 and L2, W1 and W2 is not limited to the above, and can also be set according to the actual situation, as long as the connection reliability between the insulating tape 3 and the electrode assembly 2 can be improved, and the electrode assembly 2 can be prevented from being damaged. It can be damaged.

In a specific embodiment, as shown in FIG. 1 to FIG. 3 , the insulating tape 3 includes a first glue material 33 , a base material 35 and a second glue material 34 which are arranged in layers, wherein the base material 35 is located in the first glue material 34 . between the adhesive material 33 and the second adhesive material 34, and connected with the two, the first adhesive material 33 and the base material 35 may be bonded, and the second adhesive material 34 and the base material 35 may also be bonded The first adhesive material 33 is used for bonding with the electrode assembly 2 , that is, the first surface 31 is disposed on the first adhesive material 33 , and the second adhesive material 34 is used for bonding with the casing 1 , that is, the second surface 32 arranged on the second glue material 34 .

Wherein, in the embodiment shown in FIG. 1 , when the first surface 31 includes the first bonding area 311 and the second bonding area 312 , the first adhesive material 33 may include at least two adhesive material monomers, and the two The bonding strengths of the individual glue materials are P1 and P2, respectively, so that the bonding strengths of the first bonding area 311 and the second bonding area 312 are P1 and P2, respectively. The insulating tape 3 can be an integral structure, that is, two glue material monomers are coated on the same substrate 35 and connected to each other; the insulating tape 3 can also be a separate structure, that is, two glue material single The body is coated on the same substrate 35, but there is a gap between them, or the two glue material monomers are coated on the two substrates 35 respectively.

In the embodiment shown in FIG. 4 to FIG. 6 , when the second surface 32 includes the third bonding area 321 and the fourth bonding area 322 , the second adhesive material 34 may include at least two adhesive material monomers, and The bonding strengths of the two glue material monomers are P3 and P4 respectively, so that the bonding strengths of the third bonding area 321 and the fourth bonding area 322 are P3 and P4 respectively. The insulating tape 3 can be an integral structure, that is, two glue material monomers are coated on the same substrate 35 and connected to each other; the insulating tape 3 can also be a separate structure, that is, two glue material single The body is coated on the same substrate 35, but there is a gap between them, or the two glue material monomers are coated on the two substrates 35 respectively.

In the embodiment shown in FIG. 7 to FIG. 9 , the first surface 31 includes a first bonding area 311 and a second bonding area 312 , and the second surface 32 includes a third bonding area 321 and a fourth bonding area At 322, the first glue material 33 may include at least two glue material monomers, and the bonding strengths of the two glue material monomers are respectively P1 and P2, and the second glue material 34 may include at least two glue material monomers, And the bonding strengths of the two glue material monomers are P3 and P4 respectively, so that the bonding strengths of the first bonding area 311 and the second bonding area 312 are P1 and P2, respectively, and the third bonding area 321 and The bonding strengths of the fourth bonding areas 322 are P3 and P4, respectively. The insulating tape 3 can be an integral structure, that is, the individual adhesives are coated on the same substrate 35, and the individual adhesives located on the same side of the substrate 35 are connected to each other; the insulating tape 3 can also be provided as a separate body structure, that is, the adhesive material monomers are all coated on the same substrate 35, but there is a gap between the adhesive material monomers located on the same side of the substrate 35, or the adhesive material monomers whose bonding strengths are P1 and P3 respectively. The body is coated on the front and back sides of one base material 35 , and the adhesive material monomers with bond strengths of P2 and P4 respectively are coated on the front and back sides of another base material 35 .

In the above embodiments, as shown in FIG. 11 , in the insulating tape 3, the shapes of the first surface 31 and the second surface 32 are selected from any one of square, rectangle, trapezoid, octagon, circle, and ellipse. kind.

Taking the lithium-ion battery whose projection surface is a rectangle as an example, the drop passing rate test is carried out. The length L1 of the electrode assembly 2 of the selected rectangular lithium-ion battery is 87 mm, and the width W1 is 64 mm. In the insulating tape 3, the first bonding There are a second bonding area 312 and a fourth bonding area 322 around the area 311 and the third bonding area 321 respectively, P1 and P3 are 10MPa, P2 and P4 are 8MPa, and the lithium-ion battery is set to repeat the experiment at each position The number of times is 20 times, and the pass rate is required to be no less than 80% (that is, at least 16 cells do not fail when they are dropped) to be qualified, and the drop condition is six sides and four corners. The shape and size of the first surface 31 and the second surface 32 of the base group are the same, and both sides are a single adhesive layer with a bonding strength of 10 MPa. The test results obtained according to the different shapes of the first surface 31 and the second surface 32 of the insulating tape 3 are shown in the following table.

Shape of the first and second surfaces	Number of failures	Passing rate(%)
square	0	100
rectangle	0	100
trapezoid	1	95
Octagon	0	100
round	0	100
Oval	0	100
Base group	5	75

According to the test results in the above table, it can be seen that after the insulating tape 3 of the present application is installed, the electrochemical device has a high pass rate during the drop test, and when the first surface 31 and/or the second surface 32 are any of the above All shapes can pass the drop test.

The electrochemical devices in the embodiments of the present application can be used in various fields. As long as the devices that can be powered by the electrochemical devices can be used, the electrochemical devices in the embodiments of the present application can be used. For example, the electrochemical device can be used in components such as electrochemical device packages and electronic devices for electric vehicles, and the electronic devices can be mobile phones, tablet computers, desktop computers, laptop computers, handheld computers, notebook computers, and super mobile personal computers. (ultra-mobile personal computer, UMPC), netbooks, and cellular phones, personal digital assistants (personal digital assistants, PDAs), augmented reality (augmented reality, AR) devices, virtual reality (virtual reality, VR) devices, artificial intelligence ( artificial intelligence (AI) equipment, wearable equipment, in-vehicle equipment, smart home equipment and/or smart city equipment, power tools, energy storage devices, electric tricycles, electric vehicles, etc. The specific types of the electronic devices are not specified in the embodiments of the present application. special restrictions.

Specifically, the electronic device may include components such as a casing, a screen, a circuit board, and an electrochemical device, wherein the screen, the circuit board, and the electrochemical device are all mounted on the casing, and the electrochemical device is described in any of the above embodiments. Electrochemical device.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims (10)

1. An electrochemical device, characterized in that the electrochemical device comprises:

   case;

   an electrode assembly, at least a portion of the electrode assembly is located within the housing; and

   an insulating tape, the insulating tape is located between the housing and the electrode assembly, and the insulating tape includes a first surface bonded to the electrode assembly and a second surface bonded to the housing; The insulating tape meets at least one of the following conditions:

   a) The first surface includes a first bonding area with a bonding strength of P1 and a second bonding area with a bonding strength of P2, 0.2×P1≤P2≤0.9×P1;

   b) The second surface includes a third bonding area with a bonding strength of P3 and a fourth bonding area with a bonding strength of P4, 0.2×P3≤P4≤0.9×P3.
2. The electrochemical device according to claim 1, wherein at least one of the following conditions is satisfied:

   c) the second bonding area has a second outer edge and a second inner edge; the width of the first surface is W2, the distance between the second inner edge and the second outer edge is h1, in,

   0.05×W2≤h1≤0.4×W2;

   d) the fourth bonding area has a fourth outer edge and a fourth inner edge; the width of the second surface is W3, the distance between the fourth inner edge and the fourth outer edge is h2, in,

   0.05×W3≤h2≤0.4×W3.
3. The electrochemical device according to claim 1, wherein at least one of the following conditions is satisfied:

   e) The area A1 of the first bonding area and the area B1 of the second bonding area satisfy:

   0.05≤B1/(A1+B1)≤0.928;

   f) The area A2 of the third bonding area and the area B2 of the fourth bonding area satisfy:

   0.05≤B2/(A2+B2)≤0.928.
4. The electrochemical device according to claim 1, wherein at least one of the following conditions is satisfied:

   g) The second adhesive area is located on one side of the first adhesive area, or the second adhesive area is located on opposite sides of the first adhesive area, or the second adhesive area is located on one side of the first adhesive area. The contact area is located around the first bonding area;

   h) The fourth adhesive area is located on one side of the third adhesive area, or the fourth adhesive area is located on opposite sides of the third adhesive area, or the fourth adhesive area The contact area is located around the third bonding area.
5. The electrochemical device according to claim 1, wherein at least one of the following conditions is satisfied:

   i) there is a gap between the first bonding area and the second bonding area;

   j) There is a gap between the third bonding area and the fourth bonding area.
6. The electrochemical device according to claim 1, wherein at least one of the following conditions is satisfied:

   k) the orthographic projection of the third bonding area on the first surface coincides with the first bonding area;

   l) The orthographic projection of the fourth bonding area on the first surface coincides with the second bonding area.
7. The electrochemical device according to claim 1, wherein at least one of the following conditions is satisfied:

   m) 0.3×P1≤P2≤0.9×P1;

   n) 0.3×P3≤P4≤0.9×P3.
8. The electrochemical device according to claim 2, wherein at least one of the following conditions is satisfied:

   o) 0.05×W2≤h1≤0.35×W2;

   p) 0.1×W3≤h2≤0.3×W3.
9. The electrochemical device according to claim 1, wherein the shape of the first surface and/or the second surface is selected from the group consisting of square, rectangle, trapezoid, octagon, circle and ellipse either.
10. An electronic device, characterized in that, the electronic device comprises the electrochemical device according to any one of claims 1 to 9 .

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