CN112103411B

CN112103411B - Electrochemical device and electronic device

Info

Publication number: CN112103411B
Application number: CN202011004166.2A
Authority: CN
Inventors: 李学成
Original assignee: Ningde Amperex Technology Ltd
Current assignee: Ningde Amperex Technology Ltd
Priority date: 2020-09-22
Filing date: 2020-09-22
Publication date: 2023-04-07
Anticipated expiration: 2040-09-22
Also published as: CN112103411A

Abstract

The application relates to an electrochemical device and an electronic device. The casing includes first casing and second casing, and first casing includes first connecting portion, and the second casing includes the second connecting portion, and first connecting portion and second connecting portion bond. The first connection portion and the second connection portion are disposed to overlap in a thickness direction of the electrochemical device. The first tab is located between the first connection portion and the second connection portion. The first shell further comprises a first bending part and a first reinforcing part, two opposite ends of the first bending part are connected with the first connecting part and the first reinforcing part respectively, and the second connecting part is located between the first connecting part and the first reinforcing part. This first kink and first rib can improve the connection reliability of first connecting portion and second connecting portion, reduce electrochemical device and fall the in-process first connecting portion and the risk that the second connecting portion junction is broken away and leads to losing efficacy, improve electrochemical device's security and life.

Description

Electrochemical device and electronic device

Technical Field

The present application relates to the field of energy storage device technology, and more particularly, to an electrochemical device and an electronic apparatus.

Background

With the development of electronic devices, batteries of the electronic devices are required to have larger capacity so as to meet the cruising requirement of the electronic devices. A battery for an electronic device generally includes a case that protects an electrode assembly and the electrode assembly located inside the case. In the use, when electronic equipment dropped, probably resulted in the casing of battery to damage, the casing damages the back, leads to the battery to become invalid, and current battery became invalid easily when dropping promptly, leads to electronic equipment to have the potential safety hazard.

Disclosure of Invention

The application provides an electrochemical device and an electronic device, which can reduce the risk of failure when the electrochemical device falls and improve the safety of electronic equipment.

A first aspect of the present application provides an electrochemical device, wherein the electrochemical device includes a case and a first tab. The casing includes first casing and second casing, and first casing includes first connecting portion, and the second casing includes the second connecting portion, and first connecting portion and second connecting portion bond. The first connection portion and the second connection portion are disposed to overlap in a thickness direction of the electrochemical device. The first tab is located between the first connection portion and the second connection portion. The first shell further comprises a first bending part and a first reinforcing part, two opposite ends of the first bending part are connected with the first connecting part and the first reinforcing part respectively, and the second connecting part is located between the first connecting part and the first reinforcing part.

In one possible design, the projections of the first reinforcement and the first tab at the first connection portion do not coincide along the thickness direction of the electrochemical device.

In one possible design, the electrochemical device further includes first bonding members disposed at both sides of the first tab, and the first bonding members are bonded to the first connection portion and the second connection portion, respectively. The projections of the first reinforcing part and the first adhesive member at the first connecting part do not coincide with each other in the thickness direction of the electrochemical device.

In one possible design, the electrochemical device further includes a second adhesive member disposed between the first reinforcement portion and the second connection portion.

In one possible design, the second adhesive comprises an adhesive comprising at least one of a nitrile polymer, a polysulfide rubber, a polyolefin, a polyacrylic acid, a polyvinyl chloride, a polybutadiene, or a perchloroethylene.

In one possible design, the first shell further includes a second bent portion and a second reinforcing portion. Two opposite ends of the second bending part are respectively connected with the first connecting part and the second reinforcing part, and the second connecting part is positioned between the first connecting part and the second reinforcing part; or the two opposite ends of the second bending part are respectively connected with the second connecting part and the second reinforcing part, and the first connecting part is positioned between the second connecting part and the second reinforcing part.

In one possible design, the first reinforcement and the second reinforcement are located on the same side or on different sides of the first tab.

In one possible design, the first housing further includes a third connecting portion, the second housing further includes a fourth connecting portion, the third connecting portion and the fourth connecting portion are bonded, and the third connecting portion and the fourth connecting portion are disposed to overlap in a thickness direction of the electrochemical device. The electrochemical device further includes a second tab, the second tab being located between the third connection portion and the fourth connection portion. The first shell further comprises a third bending part and a third reinforcing part, two ends, opposite to the third bending part, of the first shell are connected with the third connecting part and the third reinforcing part respectively, and the fourth connecting part is located between the third connecting part and the third reinforcing part.

In one possible design, the first tab projects from the housing in a first direction, and the electrochemical device satisfies at least one of the following conditions: the width of the projection of the first reinforcing part on the second connecting part along the first direction is 1mm to 10mm; along the second direction, the length of the projection of the first reinforcing part on the second connecting part is 5mm to 100mm, and the second direction is perpendicular to the first direction and is parallel to the plane where the second connecting part is located.

A second aspect of the present application provides an electronic device, wherein the electronic device includes the above electrochemical device.

In the case of the electrochemical device, the connection position of the first connection portion and the second connection portion in the tab extending direction is the weak portion thereof. In the application, through increasing first kink and first rib, can play the reinforcing action to being connected between first connecting portion and the second connecting portion, improve the joint strength of first connecting portion and second connecting portion to reduce electrochemical device and fall the risk that the in-process first connecting portion and second connecting portion junction are broken open and lead to becoming invalid, improve electrochemical device's security and life, thereby improve electronic device's security and life.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

FIG. 1 is a schematic structural view of an electrochemical device according to the prior art in a first embodiment;

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a schematic structural view of an electrochemical device according to the prior art in a second embodiment;

FIG. 4 is a side view of FIG. 3;

FIG. 5 is an enlarged view of a portion I of FIG. 2;

FIG. 6 is a schematic structural view of an electrochemical device provided herein in a first embodiment;

FIG. 7 is an enlarged view of a portion II of FIG. 6;

FIG. 8 is a schematic structural diagram of another embodiment of FIG. 7;

FIG. 9 is a schematic structural view of an electrochemical device provided in the present application in a second embodiment;

FIG. 10 is an enlarged view of a portion III of FIG. 9;

FIG. 11 is a schematic structural view of an electrochemical device provided in a third embodiment as described herein;

FIG. 12 is a schematic view of an electrochemical device provided herein with increased dimensions of a first connection portion in one embodiment;

FIG. 13 is a schematic view of the first connecting portion of FIG. 12 after bending;

FIG. 14 is a schematic view of the first connection portion of FIG. 12 with a second adhesive member;

FIG. 15 is a view of the first connecting portion of FIG. 14 after bending;

FIG. 16 is a schematic view of an electrochemical device provided herein with increased dimensions of a first connection portion in another embodiment;

FIG. 17 is a schematic view of the first connection portion of FIG. 16 with a second adhesive member;

FIG. 18 is a view of the first connecting portion of FIG. 17 after bending;

fig. 19 is a schematic structural view of an electrochemical device provided in the present application in a fourth embodiment.

Reference numerals are as follows:

1-a shell;

11-a first housing;

111-a first connection;

112-a first bending part;

113-a first reinforcement;

114-a second reinforcement;

115-a third reinforcement;

116-a third connection;

117-a first body portion;

12-a second housing;

121-a second connection;

122-a fourth connection;

123-a second body portion;

13-an outer end;

14-a first side;

15-a second side;

16-a protective layer;

17-a metal layer;

18-a tie layer;

19-gummed paper;

2-an electrode assembly;

21-a first tab;

22-a second tab;

3-a second adhesive member;

4-first adhesive member.

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

Detailed Description

In order to better understand the technical solution of the present application, the following detailed description is made with reference to the accompanying drawings.

It should be understood that the embodiments described are only a few embodiments of the present application, and not all embodiments.

The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be noted that the terms "upper", "lower", "left", "right", and the like used in the embodiments of the present application are described in terms of the angles shown in the drawings, and should not be construed as limiting the embodiments of the present application. In addition, in this context, it will also be understood that when an element is referred to as being "on" or "under" another element, it can be directly on "or" under "the other element or be indirectly on" or "under" the other element via an intermediate element.

As shown in fig. 1 and 2, an electrochemical device generally includes a case 1 and an electrode assembly 2, and the electrode assembly 2 may include a first pole piece, a second pole piece, and a separator. One of the first pole piece and the second pole piece is a positive pole, the other one is a negative pole, and the isolating film is used for separating the first pole piece and the second pole piece.

In one particular embodiment, a separator film may be supported by a thermoplastic resin, such as polyethylene or polypropylene, and serves to insulate the first and second pole pieces.

In one specific embodiment, the first pole piece comprises a first current collector and a first active material layer coated on the surface of the first current collector, and the second pole piece comprises a second current collector and a second active material layer coated on the surface of the second current collector. When the first pole piece is a positive pole piece and the second pole piece is a negative pole piece, the first current collector can be an aluminum foil, a nickel foil and the like, and the first active material layer can comprise active materials such as a ternary material, lithium manganate, lithium iron phosphate and the like. The second current collector may be a copper foil, a nickel foil, or the like, and the second active material layer may include an active material such as graphite or silicon.

In a particular embodiment, the electrode assembly 2 may further include a first tab 21 and a second tab 22. One of the first tab 21 and the second tab 22 is a positive electrode tab, and the other is a negative electrode tab. The first tab 21 is electrically connected to the first pole piece and extends from the housing 1. In a specific embodiment, the first tab 22 may be directly cut from the first current collector, i.e., the first tab 22 and the first current collector are integrally formed. In one embodiment, the second pole ear 22 is electrically connected to the second pole piece and extends from the housing 1. In a specific embodiment, the second tab 22 may be directly cut from the second current collector, i.e., the first tab 22 and the first current collector are integrally formed.

In one embodiment, the electrode assembly 2 may have a winding structure, the first electrode sheet, the separator, and the second electrode sheet are all one, the first electrode sheet, the separator, and the second electrode sheet having a band shape are stacked and wound several times to form a hollow cylindrical structure, and then the cylindrical structure is flattened into the flat electrode assembly 2.

In another embodiment, the electrode assembly 2 may also be a laminated structure, and specifically, the first pole piece, the separator, and the second pole piece are all plural, and the plural first pole pieces, the separator, and the second pole pieces are alternately laminated to form the laminated electrode assembly 2.

In one particular embodiment, the electrode assembly 2 may be heat sealed through the can 1. As shown in fig. 2, the housing 1 may specifically include a first housing 11 and a second housing 12, that is, both the first housing 11 and the second housing 12 may be packaging films, and the first housing 11 and the second housing 12 are connected together by hot pressing to form the sealed housing 1. As shown in fig. 1 and 2, the first housing 11 includes a first body 117 and a first connecting portion 111 extending outward from the first body 117, and the second housing 12 includes a second body 123 and a second connecting portion 121 extending outward from the second body 123. In the heat-seal packaging process, the first connection portion 111 and the second connection portion 121 are connected (e.g., bonded, etc.), and in the thickness direction Y of the electrochemical device, the first connection portion 111 and the second connection portion 121 are disposed to overlap, the first body portion 117 and the second body portion 123 enclose a receiving cavity for receiving an electrode unit and an electrolyte of the electrode assembly 2, and the first tab 21 and the second tab 22 of the electrode assembly 2 protrude outside the receiving cavity.

Specifically, the first tab 21 and the second tab 22 may protrude from the receiving cavity between the first connection portion 111 and the second connection portion 112. That is, the first tab 21 is located between the first connection portion 111 and the second connection portion 112, and the second tab 22 is located between the first connection portion 111 and the second connection portion 112. In order to improve the sealing performance, a first adhesive 4 is provided in the first tab 21, and the first adhesive 4 is used to improve the sealing performance among the first tab 21, the first connection portion 111, and the second connection portion 112. And a first adhesive member 4 is also provided at the second tab 22, and the first adhesive member 4 is used to improve the sealing performance between the second tab 22, the first connection part 111 and the second connection part 112, thereby reducing the risk of leakage of the electrolyte from the first tab 21 and the second tab 22.

In the embodiment shown in fig. 1, the first tab 21 and the second tab 22 extend from the same end of the electrode unit in the height direction Z. In this case, the case 1 may have an open end, i.e., may be open only at one end of the first tab 21 and the second tab 22, and may be closed at the remaining position. That is, as shown in fig. 2, the first case 11 and the second case 12 are of an integral structure with one end open, and after enclosing an accommodating chamber for accommodating the electrode unit, the case 1 is heat sealed by the first connecting portion 111 and the second connecting portion 121. Therefore, the first tab 21 is positioned between the first connection portion 111 and the second connection portion 112, and the second tab 22 is also positioned between the first connection portion 111 and the second connection portion 112 in the thickness direction Y of the electrochemical device.

In the embodiment shown in fig. 3, the first tab 21 and the second tab 22 protrude from both ends of the electrode unit in the height direction Z. At this time, as shown in fig. 4, the housing 1 has a structure with two open ends, that is, the first housing 11 and the second housing 12 have a split structure, and the first housing 11 includes a first connecting portion 111 and a third connecting portion 116, and the second housing 12 includes a second connecting portion 121 and a fourth connecting portion 122. In the heat sealing, after the first case 11 and the second case 12 are butted, the first connection portion 111 and the second connection portion 121 are connected, and the third connection portion 116 and the fourth connection portion 122 are connected, so that the accommodation chamber of the case 1 is closed, and the electrode unit is sealed. At this time, the first tab 21 protrudes from between the first connection portion 111 and the second connection portion 121 (the first tab 21 is located between the first connection portion 111 and the second connection portion 121), and the second tab 22 protrudes from between the third connection portion 116 and the fourth connection portion 122 (the second tab 22 is located between the third connection portion 116 and the fourth connection portion 122).

Specifically, as shown in fig. 5, when the housing 1 is a packaging film, the housing 1 may specifically include a protective layer 16, a metal layer 17, and a connection layer 18, which are stacked. Wherein the protective layer 16 and the connection layer 18 are respectively located on both sides of the metal layer 17, and the connection layer 18 is located on the inner side of the case 1 (the side close to the electrode assembly 2), and the protective layer 16 is located on the outer side of the case 1. Specifically, the protective layer 16 may be fixed to the surface of the metal layer 17 away from the electrode unit by an adhesive, the connection layer 18 may be fixed to the surface of the metal layer 17 close to the electrode assembly 2 by an adhesive, the protective layer 16 may be made of nylon or polyethylene terephthalate, and the protective layer 16 is used for protecting the metal layer 17; the metal layer 17 may be made of aluminum foil or iron foil, and the metal layer 17 is used to improve the mechanical strength of the housing 1 and prevent moisture and oxygen from entering the housing 1; the material of the connecting layer 18 may be polypropylene or polyethylene, and the connecting layer 18 has thermal adhesion performance, i.e. can be heat-sealed.

Therefore, as shown in fig. 5, when the first connection portion 111 of the first housing 11 is connected to the second connection portion 121 of the second housing 12, it may be connected to the connection layer 18 of the first connection portion 111 and the connection layer 18 of the second connection portion 121, and when the third connection portion 116 of the first housing 11 is connected to the fourth connection portion 122 of the second housing 12, it may be connected to the connection layer 18 of the third connection portion 116 and the connection layer 18 of the fourth connection portion 122.

In the above embodiments, when the electrochemical device falls in use, under the action of an impact force, the case 1 on the tab side is at a high risk of being broken, especially at the connection position between the first connection portion 111 and the second connection portion 121 and at the connection position between the third connection portion 116 and the fourth connection portion 122, and the case 1 is reduced in risk of being damaged when falling by changing the structure of the case 1.

Specifically, as shown in fig. 7, the first housing 11 further includes a first bending portion 112 and a first reinforcing portion 113, two opposite ends of the first bending portion 112 are respectively connected to the first connecting portion 111 and the first reinforcing portion 113, the first bending portion 112 is bent relative to the first connecting portion 111, the second connecting portion 121 is located between the first connecting portion 111 and the first reinforcing portion 113, and the second connecting portion 121 is further directly or indirectly connected to the first reinforcing portion 113.

For the case 1, the connection position of the first connection portion 111 and the second connection portion 112 is a weak portion thereof, in this embodiment, by adding the first bending portion 112 and the first reinforcing portion 113, and wrapping the second connection portion 121 through the first reinforcing portion 113, and connecting with the second connection portion 121, the connection between the first connection portion 111 and the second connection portion 121 can be reinforced, so that the risk that the connection between the first connection portion 111 and the second connection portion 121 is broken away to cause failure in the dropping process of the electrochemical device is reduced, the safety and the service life of the electrochemical device are improved, and the safety and the service life of the electronic device are improved.

Specifically, in the embodiment shown in fig. 5 and 7, the connected first and

second connection parts

111 and 121 form a connection region of the case 1 having first and

second side parts

14 and 15 oppositely disposed in a thickness direction Y of the electrochemical device and having an outer end 13 distant from the electrode assembly 2 in a height direction Z of the electrochemical device. As shown in fig. 7, after the first bending part 112 and the first reinforcing part 113 are disposed in the electrochemical device, the first bending part 112 is located at one end of the outer end 113 far away from the electrode unit (i.e., the first bending part 112 is located outside the outer end 13) along the height direction Z of the electrochemical device, and the first bending part 112 is connected to the outer end 13 of the connection region. Meanwhile, the first reinforcing part 113 is located at a side of the second side part 15 away from the first side part 14 (i.e., the first reinforcing part 113 is located at an outer side of the second side part 15) in the thickness direction Y of the electrochemical device, and the first reinforcing part 113 is connected to the second side part 14 of the connection region. Therefore, the first bending part 112 and the first reinforcing part 113 can cover and connect the outer end 13 and the second side part 14 of the connection region, thereby improving the connection reliability of the connection region (where the first connection part 111 and the second connection part 121 are connected) by the first bending part 112 and the first reinforcing part 113.

In an embodiment, as shown in fig. 7, the first bending portion 112 and the first reinforcing portion 113 may be integrally formed with the first connecting portion 111, that is, each of the first bending portion 112 and the first reinforcing portion 113 may include a protective layer 16, a metal layer 17 and a connecting layer 18, which are stacked. At this time, the first bent portion 112 and the first reinforcing portion 113 may be formed by increasing the length of the first connecting portion 111 in the height direction Z, then bending the increased length portion toward the second connecting portion 121, and then bending the increased length portion to form the first bent portion 112 and the second reinforcing portion 113.

In the embodiment shown in fig. 7, when the first bending portion 112 is directly connected to the outer end 13 of the connection region and the first reinforcing portion 113 is directly connected to the second side 15 of the connection region, the specific connection manner may be as follows: the connection layer 18 of the first bent portion 112 is directly bonded to the outer end portion 113 of the connection region (the outer end portion 113 of the connection region is an outer end portion of the second connection portion 121 in the height direction Z), and the connection layer 18 of the first reinforcing portion 113 is directly bonded to the second side portion 15 of the connection region (the second side portion 15 of the connection region is a side portion of the second connection portion 121 in the thickness direction Y), that is, the first reinforcing portion 113 is directly bonded to the second connection portion 121.

In this embodiment, when the connection layer 18 of the first bending portion 112 and the connection layer 18 of the first reinforcing portion 113 are directly connected, material can be saved and the thickness can be reduced.

In another embodiment, as shown in fig. 8, the electrochemical device may further include a second adhesive member 3, and the second adhesive member 3 is disposed between the first reinforcing part 113 and the second connecting part 121, so that the first reinforcing part 113 and the second connecting part 121 are indirectly adhered by the second adhesive member 3. In this embodiment, before the first connecting portion 111 with the increased length is bent to form the first bent portion 112 and the first reinforcing portion 113, glue (the second adhesive member 3) is applied to the second side portion 15 (the second connecting portion 121) of the connecting region, so that the first reinforcing portion 113 formed after bending can be adhered to the second connecting portion 121 through the second adhesive member 3.

In this embodiment, the second adhesive member 3 is disposed between the second connection portion 121 and the first reinforcement portion 113, so that the second side portion 15 of the connection region and the first reinforcement portion 113 can be indirectly connected through the second adhesive member 3, that is, the first reinforcement portion 113 and the second connection portion 121 are bonded through the second adhesive member 3, thereby improving the connection reliability between the first reinforcement portion 113 and the second connection portion 121, and further reducing the risk of failure of the housing 1 under the impact force.

In addition, since the first bent portion 112 and the outer end 13 of the connection region may be connected to each other, the second adhesive member 3 may be disposed between the first bent portion 112 and the outer end 13, specifically, before the first connection portion 111 is bent, a layer of glue (the second adhesive member 3) is applied to the outer end 13 of the connection region, and when the first bent portion 112 is formed after bending, the first bent portion 112 and the outer end 13 of the connection region (the outer end of the second connection portion 121) are bonded to each other by the second adhesive member 3.

Therefore, when the second adhesive member 3 is disposed between the first bent portion 112 and the second connecting portion 121 and between the first reinforcing portion 113 and the second connecting portion 121, and the first bent portion 112, the first reinforcing portion 113 and the first connecting portion 111 are integrally formed, the reliability of the housing 1 can be further improved.

In particular, the second adhesive member 3 comprises an adhesive comprising at least one of a nitrile polymer, a polysulfide rubber, a polyolefin, a polyacrylic acid, a polyvinyl chloride, a polybutadiene or a perchloroethylene. The second adhesive member 3 may also be another polymer adhesive, and in this embodiment, the specific material of the second adhesive member 3 is not limited.

In another embodiment, as shown in fig. 9 and 10, the first bending portion 112 and the first reinforcing portion 113 are not necessarily integrally formed with the first connecting portion 111. For example, the electrochemical device may further include a tape 19, and the tape 19 covers a connection region formed by connecting the first connection portion 111 and the second connection portion 121, that is, the tape 19 forms the first bending portion 112 and the first reinforcing portion 113.

Specifically, as shown in fig. 10, the adhesive tape 19 is connected to the first side portion 14 of the connection area, the second side portion 15 of the connection area, and the outer end portion 13 of the connection area, and specifically, the following two ways may be adopted: firstly, the adhesive tape 19 is directly bonded with the first side part 14, the adhesive tape 19 is directly bonded with the second side part 15, and the adhesive tape 19 is directly bonded with the outer end part 13; second, adhesive may be disposed between the adhesive paper 19 and the first side portion 14, between the adhesive paper 19 and the second side portion 15, and between the adhesive paper 19 and the outer end portion 13, so as to be bonded by the adhesive. Therefore, in the present embodiment, the first bending portion 112, the first reinforcing portion 113 and the first connecting portion 111 are fixedly connected.

In the above embodiments, as shown in fig. 7, the first reinforcing part 113 and the first tab 21 do not overlap with each other in the projection of the first connecting part 111 in the thickness direction Y of the electrochemical device.

Since the first tab 21 extends from the position between the first connection portion 111 and the second connection portion 121, and in order to ensure that the electrochemical device can work normally, the electric energy of the electrode assembly 2 needs to be extracted through the first tab 21, the first bending portion 112 and the first reinforcing portion 113 cannot wrap the first tab 21. In this embodiment, when the projection of the first reinforcing portion 113 on the first connection portion 111 and the projection of the first tab 21 on the first connection portion 111 are staggered along the thickness direction Y of the electrochemical device, the first tab 21 can be prevented from being covered by the first reinforcing portion 113 and the first bending portion 112, that is, the first tab 21 can be exposed, so as to lead out the electric energy of the electrode assembly 2.

Meanwhile, when the first tab 21 and the second tab 22 extend from the same side of the electrochemical device in the height direction Z, that is, the first tab 21 and the second tab 22 both extend from between the first connection portion 111 and the second connection portion 121, and along the thickness direction Y of the electrochemical device, the projection of the first reinforcing portion 113 on the first connection portion 111 does not overlap the projection of the first tab 21 on the first connection portion 111, and the projection of the first reinforcing portion 113 on the first connection portion 111 does not overlap the projection of the second tab 22 on the first connection portion 111.

On the other hand, as described above, the first tab 21 is provided with the first adhesive member 4, the first adhesive member 4 is used to improve the sealing performance among the first tab 21, the first connection portion 111, and the second connection portion 112, and the first adhesive member 4 covers both sides of the first tab 21, thereby reducing the risk of leakage of the electrolyte from the first tab 21. At the same time, the first reinforcing part 113 and the first adhesive member 4 do not overlap each other in the projection onto the first connection part 111 in the thickness direction Y of the electrochemical device, so that the first reinforcing part 113 and the first adhesive member 4 can be prevented from interfering with each other.

In the above embodiments, the first housing 11 may include one or more bending portions and reinforcing portions.

As shown in fig. 1, the case 1 has a first region a, a second region B and a third region C along the width direction X of the electrochemical device, wherein the first region a is a region of the first tab 21 away from the second tab 22, the second region B is a region of the second tab 22 away from the first tab 21, and the third region C is a region between the first tab 21 and the second tab 22. It is understood that the above three regions may be used for providing the reinforcing portion and the bending portion, that is, the first reinforcing portion 113 and the second reinforcing portion 114 may be arbitrarily provided in the above three regions.

As shown in fig. 11, the first housing 11 only includes the first bending portion 112 and the first reinforcing portion 113, and the first bending portion 112 and the first reinforcing portion 113 are located between the first tab 21 and the second tab 22, that is, the first reinforcing portion 113 is located in the third area C shown in fig. 1, or the first bending portion 112 and the first reinforcing portion 113 may also be located in the first area a and the second area B shown in fig. 1.

When the electrochemical device includes the first reinforcing part 113 and the second reinforcing part 114, the first reinforcing part 113 and the second reinforcing part 114 can be located in any of the first region a, the second region B, and the third region C described above. At this time, the first reinforcement portion 113 and the second reinforcement portion 114 may be located on the same side or different sides of the first tab 21 in the width direction X of the electrochemical device.

In the first embodiment, the first case 11 may further include a second bending portion and a second reinforcing portion 114, that is, the first case 11 includes two bending portions and two reinforcing portions, the first bending portion 112 and the second bending portion may be distributed along the width direction X of the electrochemical device, and the first reinforcing portion 113 and the second reinforcing portion 114 are distributed along the width direction X of the electrochemical device. Two opposite ends of the second bending portion are connected to the first connecting portion 111 and the second reinforcing portion 114, respectively, and the second connecting portion 121 is located between the first connecting portion 111 and the second reinforcing portion 114. At this time, the first bent portion 112 and the second bent portion have the same bending direction along the thickness direction Y of the electrochemical device.

In another embodiment, two opposite ends of the second bending portion are respectively connected to the second connecting portion 121 and the second reinforcing portion 114, and the first connecting portion 111 is located between the second connecting portion 121 and the second reinforcing portion 114. At this time, the first bent portion 112 and the second bent portion are bent in opposite directions in the thickness direction Y of the electrochemical device.

In this embodiment, by providing a plurality of bent portions and a plurality of reinforcing portions on the first case 11, the connection reliability between the first case 11 and the second case 12 can be further improved, thereby reducing the risk of failure of the electrochemical device due to damage to the case 1 when the electrochemical device is dropped.

In the embodiment shown in fig. 13, the first reinforcing portion 113 and the second reinforcing portion 114 are located on different sides of the first tab 21 in the width direction X, and when the first tab 21 and the second tab 22 extend from the same end in the height direction Z, the first reinforcing portion 113 is located on a side of the first tab 21 away from the second tab 22, and the second reinforcing portion 114 is located on a side of the second tab 22 away from the first tab 21 in the width direction X. As shown in fig. 12, the first connecting portion 111 of the first housing 11 is increased in size in the height direction Z, and as shown in fig. 13, the portion of the first connecting portion 111 increased in size is bent to form a first bent portion 112 and a first reinforcing portion 113, and a second bent portion and a second reinforcing portion 114, and at this time, the first reinforcing portion 113 is directly bonded to the connection region, and the second reinforcing portion 114 is directly bonded to the connection region.

In the embodiment shown in fig. 14 and 15, before the bending, the second adhesive member 3 is disposed between the connection region and the portion of the first connection portion 111 having the increased size, and then the first connection portion 111 is bent to form the first bent portion 112 and the first reinforcing portion 113, and to form the second bent portion and the second reinforcing portion 114. At this time, the first reinforcing portion 113 and the connection region are indirectly bonded to each other by the second adhesive 3, and the second reinforcing portion 114 and the connection region are indirectly bonded to each other by the second adhesive 3.

In the embodiment shown in fig. 18, the first shell 11 includes three bending portions and three reinforcing portions, and the three reinforcing portions are respectively located in the first region a, the second region B and the third region C. As shown in fig. 16, the first connection portion 111 of the three regions is first increased in size in the height direction Z, and as shown in fig. 17, the second adhesive member 3 is provided at the portion where the size of the first connection portion 111 is increased, and then bent, thereby forming the first reinforcing portion 113 and the second reinforcing portion 114 as shown in fig. 18. Of course, the step of providing the second adhesive material 3 shown in fig. 17 may be omitted so that the first reinforcing portion 113 is directly connected to the connection region and the second reinforcing portion 114 is directly connected to the connection region.

As shown in fig. 19, the first tab 21 and the second tab 22 extend from both ends of the electrochemical device in the height direction Z, that is, the first tab 21 extends from between the first connection portion 111 of the first case 11 and the second connection portion 121 of the second case 12, and the second tab 22 extends from between the third connection portion 116 of the first case 11 and the fourth connection portion 122 of the second case 12. The first case 11 may include a first bent portion 112, a first reinforced portion 113, a third bent portion 112, and a third reinforced portion 115, where the first bent portion 112 and the second bent portion are respectively located at two ends of the electrochemical device along the height direction Z, and the first reinforced portion 113 and the second reinforced portion 115 are respectively located at two ends of the electrochemical device along the height direction Z. The two opposite ends of the third bending portion are respectively connected to the third connecting portion 116 and the third reinforcing portion 115, the fourth connecting portion 122 is located between the third connecting portion 116 and the third reinforcing portion 115, and the third reinforcing portion 115 is connected to the fourth connecting portion 122.

In the above embodiments, the first tab 21 protrudes from the housing 1 in the first direction, and the electrochemical device satisfies at least one of the following conditions: the width of the projection of the first reinforcing part 113 on the second connecting part 121 along the first direction is 1mm to 10mm; the length of the projection of the first reinforcing portion 113 on the second connecting portion 121 is 5mm to 100mm along a second direction, wherein the second direction is perpendicular to the first direction and parallel to the plane of the second connecting portion 121. For example, the first direction may be a height direction Z of the electrochemical device, and the second direction may be a width direction X of the electrochemical device.

In the present embodiment, the above-mentioned size of the first reinforcing portion 113 indicates a size in which the first reinforcing portion 113 covers the second connecting portion 121.

In example 1, in an electrochemical device having a height of 90mm, a width of 66mm, and a thickness of 4.8mm, a dimension increasing region having a width of 3mm in the first direction and a length of 12mm in the second direction was provided in the first connecting portion 111 of the first region a, a dimension increasing region having a width of 3mm in the first direction and a length of 12mm in the second direction was provided in the first connecting portion 111 of the second region B, and then both the dimension increasing regions were bent to form the first reinforcing portion 113 and the second reinforcing portion 114.

The battery cell is subjected to drop test, and the test method comprises the following steps:

1) Placing the electrochemical device in a special fixture;

2) The electrochemical device is freely dropped to the surface of the steel plate from a position with the height of 1.8 m for 3 wheels;

3) Measuring and recording the voltage of the electrochemical device after each round of test is finished, checking the appearance of the electrochemical device, and stopping drop test when the electrochemical device leaks and catches fire;

4) And (4) disassembling the electrochemical device after the drop test is finished, and counting the punching condition of the side seal of the lug of the shell 1 of the electrochemical device.

The results based on the above drop test method are given in the following table: (test a electrochemical devices, if there are b cases that are punched out, it is recorded as b/a)

Group of	Test results
		Example 1	0/10
Comparative example	6/10

As is clear from the drop results, in the case of the example 1, the case 1 was not pushed open when the drop test was performed 10 times, whereas in the comparative example (where the reinforcing portion and the bent portion were not provided), the case 1 was pushed open when the drop test was performed 10 times, in the test 6 times. Obviously, when adding kink and reinforcing part in this application, can effectively alleviate the problem that casing 1 utmost point ear side seal was broken when falling to improve casing 1's the performance of falling.

The electrochemical device in the embodiments of the present application may be used in various fields, and the electrochemical device in the embodiments of the present application may be used as long as the device capable of supplying power using the electrochemical device can be used. For example, the electrochemical device may be used in an electrochemical device package of an electric vehicle, an electronic device, and the like, and the electronic device may be a mobile phone, a tablet computer, a desktop computer, a laptop computer, a handheld computer, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook, a cellular phone, a Personal Digital Assistant (PDA), an Augmented Reality (AR) device, a Virtual Reality (VR) device, an Artificial Intelligence (AI) device, a wearable device, a vehicle-mounted device, a smart home device and/or a smart city device, an electric tool, an energy storage device electric tricycle, an electric vehicle, and the like.

Specifically, the electronic device may include a housing, a screen, a circuit board, and an electrochemical device, wherein the screen, the circuit board, and the electrochemical device are mounted to the housing, and the electrochemical device is the electrochemical device described in any of the above embodiments.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An electrochemical device, wherein the electrochemical device comprises:

a case including a first case and a second case, the first case including a first connection portion, the second case including a second connection portion, the first connection portion and the second connection portion being bonded, the first connection portion and the second connection portion being disposed to overlap in a thickness direction of the electrochemical device;

a first tab positioned between the first connection portion and the second connection portion;

the first bonding pieces are arranged on two sides of the first tab and are bonded with the first connecting part and the second connecting part respectively; the first shell further comprises a first bending part and a first reinforcing part, two opposite ends of the first bending part are connected with the first connecting part and the first reinforcing part respectively, and the second connecting part is located between the first connecting part and the first reinforcing part.

2. The electrochemical device according to claim 1, wherein projections of the first reinforcing part and the first tab at the first connection part do not coincide in a thickness direction of the electrochemical device.

3. The electrochemical device according to claim 1,

the projections of the first reinforcing part and the first adhesive member at the first connection part do not overlap in the thickness direction of the electrochemical device.

4. The electrochemical device according to claim 1, further comprising a second adhesive member disposed between the first reinforcement part and the second connection part.

5. The electrochemical device of claim 4, wherein the second adhesive comprises an adhesive comprising at least one of a nitrile polymer, a polysulfide rubber, a polyolefin, a polyacrylic acid, a polyvinyl chloride, a polybutadiene, or a perchloroethylene.

6. The electrochemical device according to claim 1, wherein the first case further comprises a second bent portion and a second reinforcing portion;

two opposite ends of the second bending part are respectively connected with the first connecting part and the second reinforcing part, and the second connecting part is positioned between the first connecting part and the second reinforcing part, or

The two opposite ends of the second bending part are respectively connected with the second connecting part and the second reinforcing part, and the first connecting part is located between the second connecting part and the second reinforcing part.

7. The electrochemical device according to claim 6, wherein the first reinforcement portion and the second reinforcement portion are located on the same side or different sides of the first tab.

8. The electrochemical device according to claim 1, wherein the first case further includes a third connecting portion, the second case further includes a fourth connecting portion, the third connecting portion and the fourth connecting portion are bonded, and the third connecting portion and the fourth connecting portion are disposed to overlap in a thickness direction of the electrochemical device;

the electrochemical device further includes a second tab located between the third connection portion and the fourth connection portion;

the first shell further comprises a third bending part and a third reinforcing part, two opposite ends of the third bending part are connected with the third connecting part and the third reinforcing part respectively, and the fourth connecting part is located between the third connecting part and the third reinforcing part.

9. The electrochemical device of claim 1, wherein the first tab protrudes from the housing in a first direction, the electrochemical device satisfying at least one of the following conditions:

the width of the projection of the first reinforcing part on the second connecting part is 1mm to 10mm along the first direction;

along the second direction, the length of the projection of the first reinforcing part on the second connecting part is 5mm to 100mm, and the second direction is perpendicular to the first direction and is parallel to the plane where the second connecting part is located.

10. An electronic device, wherein the electronic device comprises the electrochemical device of any one of claims 1 to 9.