CN219180636U

CN219180636U - Battery cell

Info

Publication number: CN219180636U
Application number: CN202320114510.6U
Authority: CN
Inventors: 欧阳光; 单亚平; 邹浒
Original assignee: Zhuhai Cosmx Battery Co Ltd
Current assignee: Zhuhai Cosmx Battery Co Ltd
Priority date: 2023-01-20
Filing date: 2023-01-20
Publication date: 2023-06-13
Anticipated expiration: 2033-01-20

Abstract

The utility model provides a battery, which comprises a cap, a battery cell and a shell, wherein the cap is arranged on the battery cell; the shell is provided with a containing cavity and at least one open end, the battery cell is contained in the containing cavity, and the cap covers and seals the open end; the battery cell comprises a first tab and a second tab; the cap comprises a first top cover, an insulating layer and a second top cover which are sequentially stacked; the first tab is connected with the first top cover, and the second tab is connected with the second top cover; the adhesive force between the first top cover and the insulating layer is smaller than the adhesive force between the second top cover and the insulating layer. According to the battery disclosed by the utility model, when the internal pressure is higher, the first top cover is separated from the insulating layer, so that the pressure relief in the battery is realized, the explosion of the battery is prevented, and the safety performance of the battery is further improved.

Description

Battery cell

Technical Field

The embodiment of the utility model relates to the technical field of new energy, in particular to a battery.

Background

At present, the button battery has the advantages of high material utilization rate and high energy density, and is widely applied to various portable equipment as an energy storage unit, but when the internal temperature or pressure of the current button battery is high, the internal pressure of the current button battery is difficult to release, and the battery is easy to fail or explode.

Disclosure of Invention

Therefore, the embodiment of the utility model provides a battery, wherein when the internal pressure of the battery is higher, the first top cover is separated from the insulating layer, so that the pressure relief inside the battery is realized, the explosion of the battery is prevented, and the battery has excellent safety performance.

The utility model provides a battery, which comprises a cap, a battery core and a shell, wherein the cap is arranged on the battery core;

the shell is provided with a containing cavity and at least one open end, the battery cell is contained in the containing cavity, and the cap covers and seals the open end;

the battery cell comprises a first tab and a second tab;

the cap comprises a first top cover, an insulating layer and a second top cover which are sequentially stacked;

the first tab is connected with the first top cover, and the second tab is connected with the second top cover;

the adhesive force between the first top cover and the insulating layer is smaller than the adhesive force between the second top cover and the insulating layer.

The battery as described above, wherein an adhesive area between the first top cover and the insulating layer is smaller than an adhesive area between the second top cover and the insulating layer.

The battery as described above, wherein the outer edge of the insulating layer protrudes beyond the outer edge of the second top cover by a smaller dimension than the inner edge of the insulating layer protrudes beyond the inner edge of the first top cover.

The battery as described above, wherein the first top cover includes a first top cover body and a first passivation layer, and the first passivation layer is at least disposed on a functional surface of the first top cover body adjacent to the insulating layer;

the adhesive force between the first passivation layer and the insulating layer is smaller than the adhesive force between the second top cover and the insulating layer.

The battery as described above, wherein the second top cover includes a second top cover body and a second passivation layer, and the second passivation layer is at least disposed on a functional surface of the second top cover body adjacent to the insulating layer;

the adhesive force between the first passivation layer and the insulating layer is smaller than the adhesive force between the second passivation layer and the insulating layer.

The battery as described above, wherein the first passivation layer is a nickel layer, a copper oxide layer, or a nickel-copper oxide composite layer; and/or the number of the groups of groups,

the second passivation layer is an aluminum oxide layer.

The battery as described above, wherein the insulating layer includes an insulating base, a transition layer, and an adhesive layer;

the transition layer is arranged on at least one functional surface of the insulating substrate, the bonding layer is arranged on the functional surface of the transition layer far away from the insulating substrate, and the bonding layer far away from the functional surface of the transition layer is bonded with the first top cover and/or the second top cover.

The battery as described above, wherein the melting point of the adhesive layer is smaller than the melting point of the insulating base; and/or the number of the groups of groups,

the transition layer has a melting point less than that of the adhesive layer.

The battery as described above, wherein the thickness of the adhesive layer and the thickness of the first passivation layer and/or the second passivation layer is (5-10): 1.

The battery as described above, wherein the insulating layer has a first through hole, and the first top cover has a second through hole;

the second top cover comprises a connecting part and a convex part connected with the connecting part, and the connecting part, the insulating layer and the first top cover are arranged in a stacked manner; the convex part faces the first top cover and sequentially stretches into the first through hole and the second through hole;

a gap and/or an insulating layer is arranged between the first top cover and the convex part.

The battery as described above, wherein the length of the orthographic projection of the second top cover on the functional surface of the first top cover is 1mm or more; and/or the number of the groups of groups,

the ratio of the area of the functional surface of the first cap to the area of the functional surface of the insulating layer is (10-1): 1.

the battery as described above, wherein the thickness of the insulating layer is 25 to 100 μm; and/or the number of the groups of groups,

the outer diameter of the insulating layer is 6.7-8.7mm; and/or the number of the groups of groups,

the inner diameter of the insulating layer is 4.2-5.7mm.

According to the battery, the adhesive force between the first top cover and the insulating layer in the cap is smaller than the adhesive force between the second top cover and the insulating layer, when the internal pressure of the battery is higher, the first top cover can be separated from the insulating layer, so that the pressure relief in the battery is realized, explosion of the battery caused by higher internal pressure can be avoided, and the safety performance of the battery is improved.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions of the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is apparent that the drawings in the following description are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of a battery according to some embodiments of the present utility model;

FIG. 2 is a schematic view of a cap according to some embodiments of the present utility model;

fig. 3 is a schematic structural diagram of an insulating layer according to some embodiments of the present utility model.

Reference numerals illustrate:

1: a housing;

2: a first top cover;

3: an insulating layer;

4: a second top cover;

5: a cover plate;

21: a second through hole;

31: a first through hole;

32: an insulating base;

33: a transition layer;

34: an adhesive layer;

41: a convex portion;

42: a third through hole;

43: and a connecting part.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The functional surfaces in the present utility model refer to two surfaces of the structure with the largest area and opposite to each other. Illustratively, the functional surface of the insulating layer refers to the two surfaces of the insulating layer that are the largest in area and are oppositely disposed.

Fig. 1 is a schematic structural view of a battery according to some embodiments of the present utility model, and fig. 2 is a schematic structural view of a cap according to some embodiments of the present utility model. As shown in fig. 1 and 2, a first aspect of the present utility model provides a battery including a cap, a battery cell, and a case 1;

the shell 1 is provided with a containing cavity and at least one open end, the battery cell is contained in the containing cavity, and the cap covers the open end;

the battery cell comprises a first electrode lug and a second electrode lug;

the cap comprises a first top cover 2, an insulating layer 3 and a second top cover 4 which are sequentially stacked;

the first tab is connected with the first top cover 2, and the second tab is connected with the second top cover 4;

the adhesive force between the first top cover 2 and the insulating layer 3 is smaller than the adhesive force between the second top cover 4 and the insulating layer 3.

The housing 1 of the present utility model may have one open end, and the cap covers and seals the open end, and the housing 1 of the present utility model may have two opposite open ends, and the two caps may cover and seal the two open ends, respectively. In the present utility model, if the electrical properties of the housing 1 and the first top cover 2 are the same, the housing 1 and the first top cover 2 are welded, and if the electrical properties of the housing 1 and the second top cover 4 are the same, the housing 1 and the second top cover 4 are welded.

In the utility model, the electrical property of the first tab is opposite to that of the second tab, and if the first tab is the positive tab, the second tab is the negative tab; if the first tab is a negative tab, the second tab is a positive tab.

In the utility model, the first tab is taken as a negative tab, the second tab is taken as a positive tab, and the electrical property of the shell 1 is the same as that of the first top cover 2. When the first tab is a negative tab and the second tab is a positive tab, the first top cover 2 is a top cover negative electrode and the second top cover 4 is a top cover positive electrode.

In the utility model, the cap comprises a first top cover 2, an insulating layer 3 and a second top cover 4 which are sequentially stacked, wherein the insulating layer 3 is used for preventing the first top cover 2 and the second top cover 4 from contacting to cause short circuit. The battery cell is accommodated in the accommodating cavity, a first tab in the battery cell is connected with the first top cover 2, then extends out of the shell 1 to be communicated with an external circuit, and a second tab is connected with the second top cover 4, then extends out of the shell 1 to be communicated with the external circuit.

Because the bonding force between the first top cover 2 and the insulating layer 3 in the cap is smaller than the bonding force between the second top cover 4 and the insulating layer 3, when the internal pressure of the battery comprising the cap is higher, the first top cover 2 can be separated from the insulating layer 3, so that the pressure relief inside the battery is realized, the explosion of the battery caused by higher internal pressure can be avoided, and the safety performance of the battery is improved.

In some embodiments of the present utility model, when the bonding area between the first top cover 2 and the insulating layer 3 is smaller than the bonding area between the second top cover 4 and the insulating layer 3, it is possible to achieve that the bonding force between the first top cover 2 and the insulating layer 3 is smaller than the bonding force between the second top cover 4 and the insulating layer 3.

In some embodiments of the utility model, the outer edge of the insulating layer 3 protrudes beyond the outer edge of the second cap 4 by a smaller dimension than the inner edge of the insulating layer 3 protrudes beyond the inner edge of the first cap 2.

As shown in fig. 2, the insulating layer 3 of the present utility model has a first through hole 31, and the first cap 2 has a second through hole 21. In the present utility model, the outer edge of the insulating layer 3 refers to the outermost edge of the insulating layer 3, the inner edge of the insulating layer 3 refers to the edge formed by the first through hole 31, the inner edge of the first top cover 2 refers to the edge formed by the second through hole 21, and the outer edge of the second top cover 4 refers to the outermost edge of the second top cover 4.

It will be appreciated that in the present utility model, the outer edge of the first cap 2 extends beyond the outer edge of the insulating layer 3, the outer edge of the insulating layer 3 extends beyond the outer edge of the second cap 4, and the inner edge of the insulating layer 3 extends beyond the inner edge of the first cap 2. When the size that the outer edge of the insulating layer 3 extends out of the outer edge of the second top cover 4 is smaller than the size that the inner edge of the insulating layer 3 extends out of the inner edge of the first top cover 2, the bonding area between the first top cover 2 and the insulating layer 3 can be smaller than the bonding area between the second top cover 4 and the insulating layer 3, and the bonding force between the first top cover 2 and the insulating layer 3 is smaller than the bonding force between the second top cover 4 and the insulating layer 3.

In some embodiments of the present utility model, the first cap 2 includes a first cap body and a first passivation layer disposed at least on a functional surface of the first cap body adjacent to the insulating layer 3;

the adhesive force between the first passivation layer and the insulating layer 3 is smaller than the adhesive force between the second top cover 4 and the insulating layer 3.

The utility model can only set the first passivation layer on the functional surface of the first top cover body close to the insulating layer 3 to form the first top cover 2, or set the first passivation layer on both functional surfaces of the first top cover body to form the first top cover 2.

According to the cap, the first top cover 2 comprises the first passivation layer close to the insulating layer 3, the first passivation layer can be tightly combined with the insulating layer 3, the adhesiveness between the first top cover and the insulating layer 3 is improved, and then the internal pressure threshold of the battery is improved, so that the battery can still be normally used under higher pressure, the service life of the battery is prolonged, and the safety performance of the battery is improved.

In some embodiments of the present utility model, the second top cover 4 includes a second top cover body and a second passivation layer, where the second passivation layer is at least disposed on a functional surface of the second top cover body adjacent to the insulating layer 3;

the adhesion between the first passivation layer and the insulating layer 3 is smaller than the adhesion between the second passivation layer and the insulating layer 3.

The utility model can only set the second passivation layer on the functional surface of the second top cover body close to the insulating layer 3 to form the second top cover 4, or set the second passivation layer on both functional surfaces of the second top cover body to form the second top cover 4.

According to the cap, the second top cover 4 comprises the second passivation layer close to the insulating layer 3, the second passivation layer can be tightly combined with the insulating layer 3, the adhesiveness between the second top cover 4 and the insulating layer 3 is improved, the internal pressure threshold of the battery is further improved, the battery can still be normally used under higher pressure, the service life of the battery is prolonged, and the safety performance of the battery is improved.

The first top cover body and the second top cover body are not particularly limited, and can be materials of top covers commonly used in the art. Illustratively, the first cap body may be a stainless steel layer or a copper layer and the second cap body may be an aluminum layer.

The first passivation layer is not particularly limited, and the first passivation layer may be disposed according to the first cap body. In some embodiments of the present utility model, the first passivation layer may be a nickel layer, a copper oxide layer, or a nickel-copper oxide composite layer.

In some embodiments, when the first top cover body is a copper layer, surface oxidation treatment may be performed on the copper layer, and a copper oxide layer is formed on the surface of the copper layer, where the copper oxide layer is the first passivation layer; the nickel layer on the surface of the copper layer is the negative electrode passivation layer.

The second passivation layer is not particularly limited in the present utility model, and the second passivation layer may be disposed according to the second cap body. In some embodiments of the utility model, the second passivation layer is an aluminum oxide layer.

In some embodiments, when the second top cover body is an aluminum layer, surface oxidation treatment may be performed on the aluminum layer, and an aluminum oxide layer is formed on the surface of the aluminum layer, which is the second passivation layer.

In the utility model, when the second passivation layer is an aluminum oxide layer and the first passivation layer is a copper oxide layer or a nickel layer, the adhesion between the first passivation layer and the insulating layer 3 can be smaller than the adhesion between the second passivation layer and the insulating layer 3. And the second passivation layer and the first passivation layer are tightly combined with the insulating layer 3 through hydrogen bond and van der Waals force anchoring effect, so that the pressure bearing threshold of the battery can be further improved, the battery can still be normally used under higher internal pressure, the safety performance of the battery is improved, and the service life of the battery is prolonged.

Fig. 3 is a schematic structural diagram of an insulating layer according to some embodiments of the present utility model. As shown in fig. 3, in some embodiments of the present utility model, the insulating layer 3 includes an insulating base 32, a transition layer 33, and an adhesive layer 34;

the transition layer 33 is disposed on at least one functional surface of the insulating substrate 32, and the adhesive layer 34 is disposed on a functional surface of the transition layer 33 away from the insulating substrate 32, and the adhesive layer 34 is adhered to the first top cover 2 and/or the second top cover 4 away from the functional surface of the transition layer 33.

The utility model can only set up the transition layer 33 on a functional surface of the insulating basal body 32, then set up the bond line 34 on the functional surface far away from insulating basal body 32 of this transition layer 33, form the insulating layer 3; the insulating layer 3 may be formed by providing the transition layers 33 on the two functional surfaces of the insulating base 32, and providing the adhesive layers 34 on the functional surfaces of the two transition layers 33 away from the insulating base 32.

In the utility model, the insulating substrate 32 has the functions of supporting and insulating, the functional surface of the bonding layer 34 far away from the transition layer 33 is the outer surface of the insulating layer 3, the bonding layer 34 is used for bonding with the second top cover 4 and/or the first top cover 2, and the transition layer 33 is used for bonding the bonding layer 34 and the insulating substrate 32.

When the insulating layer 3 comprises the insulating substrate 32, the transition layer 33 and the bonding layer 34, the second top cover 4 and/or the first top cover 2 can be bonded with the insulating layer 3 better, the sealing performance of the cap is improved, the internal pressure bearing threshold of the battery is improved, and the service life of the battery is prolonged.

In some embodiments of the present utility model, when the melting point of the adhesive layer 34 is less than that of the insulating substrate 32, the adhesive layer 34 can be more easily adhered to the first and/or

second caps

2 and 4, simplifying the manufacturing process of the battery.

When the melting point of the transition layer 33 is smaller than that of the adhesive layer 34, air bubbles in the insulating layer 3 can be effectively improved, air bubbles generated in the battery packaging process can be relieved, and the packaging effectiveness of the battery can be improved.

The present utility model is not particularly limited to the adhesive layer 34, the transition layer 33, and the insulating base 32, and the adhesive layer 34, the transition layer 33, and the insulating base 32 may be PP with different melting points, respectively, and PP with different melting points may be commercially available.

In some embodiments, the insulating matrix 32 is PP with a melting point of 165 ℃, the adhesive layer 34 is PP with a melting point of 157 ℃, and the transition layer 33 is PP with a melting point of 125 ℃.

In some embodiments, a metallurgic material may be added to the insulating matrix 32 to reduce the melting point of the insulating matrix 32, forming the adhesion layer 34. Illustratively, a metal additive having a melting point of 138 ℃ may be added to a PP having a melting point of 165 ℃ to form the adhesive layer 34 having a melting point of 157 ℃. In the present utility model, the adhesive layer 34 containing the metal additive has better hydrophilicity, can be more easily adhered to the first top cover 2 and/or the second top cover 4, improves the sealability of the battery and prolongs the service life of the battery.

In some embodiments of the present utility model, the thickness of the adhesive layer 34 and the thickness of the first passivation layer and/or the second passivation layer are (5-10): 1, which can make the adhesive layer 34 and the first passivation layer and/or the second passivation layer more easily adhere while saving the adhesive layer and improving the energy density of the battery.

In some embodiments of the utility model, the insulating layer 3 has a first through hole 31 and the first cap 2 has a second through hole 21;

the second top cover 4 includes a connection portion 43, a convex portion 41 connected to the connection portion 43, and the connection portion 43, the insulating layer 3, and the first top cover 2 are stacked; the convex part 41 faces the first top cover 2 and sequentially extends into the first through hole 31 and the second through hole 21;

a gap and/or an insulating layer 3 is provided between the first top cover 2 and the protruding portion 41.

Since the second top cover 4 has the convex portion 41 facing the first top cover 2, it is understood that the second top cover 4 also has the concave portion facing away from the first top cover 2 (the concave portion corresponds to the convex portion 41).

In some embodiments, the protruding portion 41 (recessed portion) has a third through hole 42, the cover plate 5 is disposed in the recessed portion, and the third through hole 42 is sealed by a lid. In the process of manufacturing the battery, electrolyte can be injected into the battery through the third through hole 42, and the third through hole 42 is sealed through the cover plate 5, so that the battery is sealed.

In some embodiments of the utility model, the length of the orthographic projection of the second cap 4 on the functional surface of the first cap 2 is 1mm or more.

It is understood that the orthographic projection of the second top cover 4 onto the first top cover 2 refers to the projection of the second top cover 4 onto the functional surface of the first top cover 2 (without taking into consideration the projection formed at the area other than the first top cover 2) by irradiating the functional surface of the second top cover 4 with incident light in a direction perpendicular to the first top cover 2.

The length of the orthographic projection of the second cap 4 on the surface of the first cap 2 refers to the distance between the outer edge of the orthographic projection and the inner edge of the orthographic projection. When the length of orthographic projection of the second top cover 4 on the surface of the first top cover 2 is more than or equal to 1mm, sealing between the second top cover 4 and the insulating layer 3 and sealing between the first top cover 2 and the insulating layer 3 can be realized, and leakage of the battery due to insufficient sealing performance is prevented.

In some embodiments of the present utility model, the ratio of the area of the functional surface of the first top cover 2 to the area of the functional surface of the insulating layer 3 is (10-1): 1, the safety performance of the battery can be better improved.

The thickness of the insulating layer 3 can be further limited, so that the burrs of the second top cover 4 and/or the first top cover 2 can be prevented from penetrating the insulating layer 3 under the conditions of saving the insulating layer 3 and improving the energy density, and short circuits caused by contact between the second top cover 4 and the first top cover 2 can be avoided. The thickness of the insulating layer 3 is, for example, 25-100 μm.

In the utility model, the insulating layer 3 can be annular, and when the insulating layer 3 is annular, the outer diameter of the insulating layer 3 can be 6.7-8.7mm; and/or the inner diameter of the insulating layer 3 may be 4.2-5.7mm.

The thickness of the adhesive layer 34, the transition layer 33 and the insulating substrate 32 in the insulating layer 3 can be further limited, so as to improve the comprehensive performance of the battery. In a specific embodiment, the insulating layer 3 comprises two adhesive layers 34 and two transition layers 33, the adhesive layers 34 having a thickness percentage of 45% (the two adhesive layers 34 having the same thickness) and the transition layers 33 having a thickness percentage of 5% (the two transition layers 33 having the same thickness) and the insulating matrix 32 having a thickness of 50% based on the total thickness of the insulating layer 3.

In the utility model, the lamination of the first top cover 2, the insulating layer 3 and the second top cover 4 can be realized through hot pressing treatment, and specifically, the method comprises the steps of sequentially placing the first top cover 2, the insulating layer 3 and the second top cover 4 on a hot-pressing sealing head for positioning, and setting the temperature of an upper hot-pressing sealing head and the temperature of a lower hot-pressing sealing head; folding the upper hot-pressing sealing head and the lower hot-pressing sealing head, and heating the upper hot-pressing sealing head and the lower hot-pressing sealing head to a set temperature; starting timing, and lifting the upper hot-pressing sealing head after a certain time to enable the first top cover 2, the insulating layer 3 and the second top cover 4 to be sealed in a hot-pressing mode;

wherein, after the hot pressing treatment, the temperature control device is used for realizing the cooling treatment of the upper hot pressing sealing head and the lower hot pressing sealing head;

the pressure of the welding head is controlled by the seal head pressing cylinder and the pressing proportion valve, and the hot pressing time can be set through a display.

In the folding process of the upper hot-pressing seal head and the lower hot-pressing seal head, the insulating layer 3 can be quickly melted at the temperature of the upper hot-pressing seal head and the lower hot-pressing seal head, so that the insulating layer 3 is bonded with the first top cover 2, and the insulating layer 3 is bonded with the second top cover 4; the melting effect of the insulating layer 3 can be controlled by controlling the pressing time and temperature, thereby controlling the thickness of the insulating layer 3, as well as the thickness of the battery.

In the present utility model, a state in which the insulating layer 3 is not melted is referred to as a first state, and a state in which the insulating layer 3 is melted is referred to as a second state (a state in which the insulating layer 3 is in a finished battery is a second state). In order to avoid lowering the energy density of the battery due to the insulating layer 3 being too thick or too much, the insulating layer 3 in the first state may be provided.

Illustratively, when the outer edge of the second top cover 4 protrudes from the outer edge of the insulating layer 3 by a size of 0.05-0.6mm and the inner edge of the insulating layer 3 protrudes from the inner edge of the first top cover 2 by a size of 0.05-0.6mm in the first state; in the second state, the outer edge of the insulating layer 3 is approximately flush with the outer edge of the second top cover 4, and the inner edge of the insulating layer 3 is approximately flush with the inner edge of the first top cover 2, so that the contact between the second top cover 4 and the first top cover 2 can be avoided, the consumption of the insulating layer 3 can be reduced, and the energy density of the battery can be improved.

In the first state, the ratio of the outer diameter of the insulating layer 3 to the thickness of the insulating layer 3 is (16.3-17.5): 1, the insulation layer 3 in the second state can be prevented from being too thin, and further, the second top cover 4 and the first top cover 2 are prevented from being in contact to cause short circuit.

In some embodiments, when the insulating layer 3 includes the adhesive layer 34, the thickness of the adhesive layer 34 in the first state may be made 20-100 μm, so that the adhesive layer 34 may be more easily adhered to the second top cover 4 and/or the first top cover 2 while saving the adhesive layer.

The technical scheme of the utility model will be further described below with reference to specific embodiments.

Examples

The battery of this embodiment is shown in fig. 1 and 2:

the battery comprises a shell 1, a battery cell (the battery cell is a common battery cell, and the selection of the battery cell does not influence the test result) and a cap;

the shell 1 is provided with an accommodating cavity, and the battery cell is accommodated in the accommodating cavity;

the battery cell comprises a first electrode lug and a second electrode lug;

the cap comprises a second top cover 4, a first top cover 2 and an insulating layer 3; the first top cover 2 is welded with the shell 1;

the second top cover 4 comprises a connecting part 43 and a convex part 41 connected with the connecting part 43, the insulating layer 3 is provided with a first through hole 31, the first top cover 2 is provided with a second through hole 21, the convex part 41 faces the first top cover 2, the convex part 41 sequentially stretches into the first through hole 31 and the second through hole 21, and the connecting part 43, the insulating layer 3 and the first top cover 2 are stacked;

the convex portion 41 has a third through hole 42, and an electrolyte (the electrolyte is a common electrolyte, the choice of the electrolyte does not affect the test result) is injected into the case 1 through the third through hole 42; the second top cover 4 also has a recess facing away from the first top cover 2, in which recess the cover plate 5 is arranged and covers the third through hole 42;

wherein the connection part 43, the insulating layer 3 and the first top cover 2 are laminated by heat pressing, and the temperature, time and pressure of the heat pressing are shown in the table 1;

the second top cover 4 comprises a second top cover body and second passivation layers arranged on two functional surfaces of the second top cover body, and the second top cover body is an aluminum layer;

the first top cover 2 comprises a first top cover body and first passivation layers arranged on two functional surfaces of the first top cover body, wherein the first top cover body is a stainless steel layer, and the first passivation layers are nickel layers;

the insulating layer 3 comprises an insulating substrate 32 and transition layers 33 arranged on two functional surfaces of the insulating substrate 32, two bonding layers 34 are respectively arranged on surfaces of the two transition layers 33 far away from the insulating substrate 32, the insulating substrate 32 is PP with a melting point of 165 ℃, the bonding layers 34 are PP with a melting point of 157 ℃, the transition layers 33 are PP with a melting point of 125 ℃, based on the total thickness of the insulating layer 3, the thickness percentage of the bonding layers 34 is 45% (the thicknesses of the two bonding layers 34 are the same), the thickness percentage of the transition layers 33 is 5% (the thicknesses of the two transition layers 33 are the same), and the thickness of the insulating substrate 32 is 50%;

the second cap 4, the first cap 2 and other relevant parameters of the insulating layer 3 are shown in table 1.

Comparative example

The battery of this comparative example was substantially the same as the battery of the example except that:

the first cap 2 does not include a first passivation layer and the relevant parameters are shown in table 1.

Performance testing

The cover plate 5 of the battery of the example was perforated with small holes, and the casing was inflated through the small holes to obtain the pressure at which the first top cover 2 and the insulating layer 3 were separated in the battery, which was called explosion test pressure, MPa, and the results are shown in table 1.

TABLE 1

As can be seen from table 1, the battery of the embodiment of the utility model has higher explosion test pressure and more excellent pressure resistance.

As can be seen from examples 1 and 2, when the bonding area of the second top cover 4 and the first top cover 2 (the outer diameter of the second top cover 4 minus the inner diameter of the first top cover 2) is reduced, the explosion test pressure is correspondingly reduced; as can be seen from examples 1 and 3, the hot pressing temperature is increased, and the explosion test pressure is correspondingly increased; as can be seen from examples 1 and 4, the thickness of the adhesive layer 34 increases, and when the ratio of the thicknesses of the first passivation layer and the adhesive layer 34 exceeds 1:10, the explosion test pressure of the battery is not substantially affected.

It should be noted that, in the description of the present utility model, the values and the ranges of values are approximate values, and may have a certain range of errors, which may be considered to be negligible by those skilled in the art, due to the influence of the manufacturing process and the measurement accuracy.

In the description of the present utility model, it should be understood that the terms "top," "bottom," "upper," "lower," and the like indicate or are used in the following description of the utility model, merely for convenience in describing the utility model and to simplify the description, but do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the utility model.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art in a specific case.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims

1. A battery is characterized by comprising a cap, a battery core and a shell;

the battery cell comprises a first tab and a second tab;

2. The battery of claim 1, wherein an adhesive area between the first cap and the insulating layer is smaller than an adhesive area between the second cap and the insulating layer.

3. The battery of claim 2, wherein the outer edge of the insulating layer extends beyond the outer edge of the second top cap by a dimension that is less than the dimension that the inner edge of the insulating layer extends beyond the inner edge of the first top cap.

4. A battery according to any one of claims 1-3, wherein the first cap comprises a first cap body and a first passivation layer disposed at least on a functional surface of the first cap body adjacent the insulating layer;

5. The battery of claim 4, wherein the second cap includes a second cap body and a second passivation layer disposed at least on a functional surface of the second cap body proximate the insulating layer;

6. The battery of claim 5, wherein the first passivation layer is a nickel layer, a copper oxide layer, or a nickel-copper oxide composite layer; and/or the number of the groups of groups,

the second passivation layer is an aluminum oxide layer.

7. The battery of claim 5 or 6, wherein the insulating layer comprises an insulating matrix, a transition layer, and an adhesive layer;

8. The battery of claim 7, wherein the adhesive layer has a melting point less than the melting point of the insulating substrate; and/or the number of the groups of groups,

the transition layer has a melting point less than that of the adhesive layer.

9. The cell of claim 8, wherein the thickness of the adhesive layer and the thickness of the first passivation layer and/or the second passivation layer is (5-10): 1.

10. The battery according to any one of claims 1-3, 5-6, 8, wherein the insulating layer has a first through hole, and the first top cover has a second through hole;

11. The battery according to any one of claims 1 to 3, 5 to 6, 8, wherein a length of orthographic projection of the second top cover on the functional surface of the first top cover is 1mm or more; and/or the number of the groups of groups,

12. the battery according to any one of claims 1-3, 5-6, 8, wherein the thickness of the insulating layer is 25-100 μm; and/or the number of the groups of groups,

the outer diameter of the insulating layer is 6.7-8.7mm; and/or

The inner diameter of the insulating layer is 4.2-5.7mm.