CN113097430A

CN113097430A - Electrochemical device and electronic device

Info

Publication number: CN113097430A
Application number: CN202110341799.0A
Authority: CN
Inventors: 侯军辉; 苏义松; 李学成
Original assignee: Ningde Amperex Technology Ltd
Current assignee: Ningde Amperex Technology Ltd
Priority date: 2021-03-30
Filing date: 2021-03-30
Publication date: 2021-07-09
Anticipated expiration: 2041-03-30
Also published as: CN113097430B

Abstract

An electrochemical device includes an electrode assembly including a pole piece, a separator, and a first adhesive member, and a case accommodating the electrode assembly. The pole piece includes first pole piece and the second pole piece of opposite polarity, and first pole piece and second pole piece are laminated and are set up, and the barrier film is used for keeping apart first pole piece and second pole piece. The outermost layer of the separator includes a first portion, a projection of which is disposed apart from a projection of the pole piece in a thickness direction of the electrode assembly. The first part extends from a part of the isolation film between the adjacent first pole piece and the second pole piece, and the first bonding piece bonds the outer surface of the outermost pole piece of the electrode assembly and the first part. The application also relates to an electronic device, and the electrochemical device can improve the short circuit problem caused by membrane turnover in the electronic device.

Description

Electrochemical device and electronic device

Technical Field

The present disclosure relates to battery manufacturing technologies, and particularly to an electrochemical device and an electronic device.

Background

The terminal equipment such as mobile phones and the like often fall off, and the falling performance of the lithium ion battery built in the terminal equipment becomes the safety performance of close attention of people. After the lithium ion battery falls down, the diaphragm is easy to turn over due to impact of free electrolyte, so that the positive and negative pole pieces are easy to contact and short-circuit due to turning over, and a larger safety risk exists; and the turnover of the diaphragm can also cause the voltage of the lithium ion battery to be reduced, and the service performance is reduced.

Disclosure of Invention

In view of the above, it is desirable to provide an electrochemical device and an electronic device, which can solve at least one of the problems of the prior art.

An embodiment of the present application provides an electrochemical device including an electrode assembly including a pole piece, a separator, and a first adhesive, and a case accommodating the electrode assembly. The pole piece comprises a first pole piece and a second pole piece with opposite polarities, and the first pole piece and the second pole piece are arranged in a stacked mode. The isolating film is used for isolating the first pole piece and the second pole piece, the outermost layer of the isolating film comprises a first part, in the thickness direction of the electrode assembly, the projection of the first part is separated from the projection of the pole pieces, and the first part is arranged by extending the part of the isolating film, which is arranged between the adjacent first pole piece and the second pole piece. The first adhesive member adheres the outer surface and the first portion of the outermost pole piece of the electrode assembly.

In the present application, the outermost portion of the separator is fixed by bonding the outermost first portion of the separator to the outermost pole piece of the electrode assembly. When the electrochemical device falls, the electrolyte in the electrochemical device impacts the isolating membrane, and the isolating membrane is fixed with the pole piece through the first bonding piece, so that the risks of short circuit and voltage reduction caused by turnover of the isolating membrane are reduced.

In a possible realization mode, the area where the first bonding piece is bonded with the first part is the second part, and the width w of the second part is more than or equal to 0.5 mm.

The width of the second part is set to be w larger than or equal to 0.5mm, so that the first bonding piece has a part exceeding the first pole piece and the second pole piece in the width direction, and the first bonding piece can be in contact with the isolation film.

In one possible implementation, the projection of the second portion onto the first portion is located within the first portion.

The projection of the second part is limited in the first part, so that the problem of interference of the second part in the process of packaging the electrochemical device can be avoided, and the electrochemical device can be packaged smoothly.

In one possible implementation, the first adhesive member also adheres to the housing.

The barrier film and the pole piece are bonded by the first bonding piece, so that the barrier film is fixed, meanwhile, the first bonding piece is bonded on the shell, the electrode assembly and the shell are further stably connected, the situation that the electrode assembly moves relative to the shell when the electrochemical device falls is reduced, and the safety of the electrode assembly is improved.

In one possible implementation, the electrode assembly is in a winding structure, and the first pole piece, the second pole piece and the separation film are arranged in a laminated winding mode.

The mode of bonding barrier film and pole piece through first bonding piece is applicable to the electrode subassembly that is the coiling structure, and the barrier film of coiling electrode subassembly intermediate position department is difficult to appear turning over the condition of rolling over.

In a possible implementation manner, the electrode assembly includes a first segment, a first bending segment, a second segment and a second bending segment which are connected in sequence along the winding direction, and the first bonding piece is bonded to the outer surface of the outermost pole piece of the first segment and/or the outer surface of the outermost pole piece of the second segment.

The tension force of the isolation film at the position of the first section and/or the second section is smaller than the tension force of the isolation film at the position of the first bending end and the second bending end, the first bonding piece is bonded on the outer surface of the outermost pole piece of the first section and/or the second section, and the bonding and fixing effects are better.

In one possible implementation, the first adhesive member further adheres the winding end of the electrode assembly.

The first bonding piece is used for increasing the area of the outermost pole piece and the first part of the isolating membrane while being bonded, so that the tail end of the electrode assembly can be fixed by the first bonding piece, and the first bonding piece can replace tail end glue for fixing.

In one possible implementation, the electrode assembly is a laminated structure, and the first pole piece, the second pole piece and the isolation film are stacked.

The mode of bonding the isolating film and the pole piece through the first bonding piece is also suitable for the electrode assembly in the laminated arrangement, and the isolating film at the middle position of the laminated electrode assembly is not easy to turn over

In one possible implementation, the electrode assembly includes a first surface and a second surface in a thickness direction of the electrode assembly, and the first adhesive member adheres the first surface and/or the second surface.

Bond first bonding piece at first surface and/or second surface, guarantee the stability that first bonding piece bonded, promote the bonding effect.

In one possible implementation, the electrode assembly further includes a second adhesive member and a first end portion, the first portion is provided at the first end portion, and the second adhesive member adheres the first end portion and both sides of the electrode assembly in a thickness direction.

The second bonding pieces are arranged and bonded on the first end portion and the two sides of the electrode assembly in the thickness direction, so that the situation that the isolating film at the middle position of the electrode assembly is folded is reduced while the isolating film at the outermost layer of the electrode assembly is fixed.

In one possible implementation, the second adhesive member adheres to a surface of the first adhesive member facing away from the pole piece.

The second bonding piece is arranged on the surface of the first bonding piece, which deviates from the pole piece, so that the condition that the first bonding piece cannot be bonded with the first part of the isolating membrane is avoided.

The embodiment of the application further provides an electronic device, which comprises a body and any one of the electrochemical devices, wherein the body comprises a containing bin, a third bonding piece is arranged on the inner wall of the containing bin, and the third bonding piece is bonded with a shell facing the first bonding piece.

The third bonding piece and the first bonding piece are arranged on the same side of the accommodating bin, so that the bonding strength between the electrochemical device and the shell is improved.

In one possible implementation, the electronic device further includes a fourth adhesive member that adheres the case where the electrode assembly faces the first adhesive member.

The fourth bonding member is added between the electrode assembly and the case, so that the bonding area between the electrode assembly and the case is increased, and the bonding strength between the electrochemical device and the case is improved.

The application provides an electrochemical device and electron device bonds through the outmost first part with the outermost pole piece of electrode subassembly of barrier film, fixes the outmost part of barrier film to improve electrochemical device and falling the in-process, the barrier film that probably appears turns over the problem of rolling over, promote electrochemical device's security performance and performance.

Drawings

Fig. 1 is a schematic perspective view of an electrochemical device according to an embodiment of the present disclosure.

Fig. 2 is a schematic top view of an electrode assembly in the electrochemical device shown in fig. 1.

Fig. 3 is a schematic front view of the electrode assembly shown in fig. 2.

Fig. 4 is a side view of the electrode assembly shown in fig. 2.

Fig. 5 is a schematic view of an electrode assembly in a lamination stack according to another embodiment.

Fig. 6 is a structural view illustrating the first adhesive simultaneously adhering the electrode assembly and the case.

Fig. 7 is a schematic top view of the electrode assembly shown in fig. 2 from another perspective.

Fig. 8 is a schematic front view of the electrode assembly shown in fig. 7.

Fig. 9 is a schematic top view of an electrode assembly provided with a second adhesive member in an electrochemical device.

Fig. 10 is a schematic top view of the electrode assembly of fig. 9 from another perspective.

Fig. 11 is a schematic front view of the electrode assembly shown in fig. 9.

Fig. 12 is a schematic top view of an electrode assembly with a first adhesive member according to another embodiment.

Fig. 13 is a schematic perspective view of an electronic device according to another embodiment of the present application.

Fig. 14 is an exploded view of the electronic device shown in fig. 13.

Description of the main elements

Electrochemical device 100

Electrode assembly 10

Pole piece 11

First pole piece 111

Second pole piece 112

Isolation diaphragm 12

First part 121

Outermost layer 122

First adhesive member 13

Second part 131

First adhesive layer 132

Substrate layer 133

Second adhesive layer 134

Width w

First stage A

First bending section B

Second section C

Second bending section D

A tail end 14

Second adhesive member 15

First end portion E

Second end part F

First surface 16

Second surface 17

Winding center O

Winding direction H

Tab 20

Housing 30

Electronic device 400

Body 40

Storage compartment 41

Third adhesive member 42

Fourth adhesive member 50

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When an element is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. The terms "top," "bottom," "upper," "lower," "left," "right," "front," "rear," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

In this application, through bonding the outmost first part of barrier film and the outmost pole piece of electrode subassembly, the outmost part of fixed barrier film, when electrochemical device took place to fall the condition, its inside electrolyte assaulted the barrier film, and the barrier film is fixed with the pole piece through first bonding piece, has reduced the barrier film and has rolled over the short circuit that leads to and the risk that the voltage reduces.

Some embodiments will be described below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

Referring to fig. 1, 2, 3 and 4, an electrochemical device 100 according to an embodiment of the present disclosure includes an electrode assembly 10, a case 30 and a first adhesive member 13, wherein the case 30 accommodates the electrode assembly 10 therein to protect the electrode assembly 10. In order to enable the electrochemical device 100 to be used normally, an electrolyte (not shown) may be injected into the case 30 to facilitate movement of ions (e.g., lithium ions) in the electrode assembly 10, so that the electrochemical device 100 can be charged and discharged normally. The first adhesive 13 is bonded to the electrode assembly 10 to fix a portion of the structure in the electrode assembly 10.

In some embodiments, the electrochemical device 100 further comprises a tab 20, the tab 20 being electrically connected to the pole piece 11.

Referring to fig. 2, 3 and 4, for better illustration of the electrochemical device 100, reference will be made to X, Y, Z coordinate axes, wherein X, Y, Z coordinate axes are perpendicular to each other. The width direction of the housing 30 is a first direction X, the length direction of the housing 30 is a second direction Y, and the thickness direction of the housing 30 is a third direction Z. In some embodiments, the extending direction of the tab 20 is a second direction Y, and a direction perpendicular to the extending direction of the tab 20 is a first direction X. Further, the length of the housing 30 refers to a distance between points having a greater value as a length, not greater than the value of the length or a width at the side of the length, and a thickness perpendicular to the length and the width, respectively. Wherein the dotted lines represent the edges of the pole piece 11.

Specifically, the electrode assembly 10 includes two pole pieces 11 and a separation film 12, and the separation film 12 is disposed between two adjacent pole pieces 11 and is used to separate the two pole pieces 11, so as to reduce the occurrence of short circuit of the electrochemical device 100 caused by the connection of the pole pieces 11.

The pole piece 11 includes a first pole piece 111 and a second pole piece 112, the isolation film 12 is disposed between the first pole piece 111 and the second pole piece 112, and the first pole piece 111, the isolation film 12 and the second pole piece 112 are stacked. In one embodiment, the first pole piece 111 is a positive pole piece, and the second pole piece 112 is a negative pole piece. The isolation film 12 is used to separate the positive and negative electrode plates from each other.

It is understood that in other embodiments, the polarities of the first and

second pole pieces

111 and 112 may be interchanged.

In the present embodiment, the electrode assembly 10 is a wound structure in which the first electrode tab 111, the separator 12, and the second electrode tab 112 are stacked and then wound to form the electrode assembly 10.

It is understood that in other embodiments, electrode assembly 10 may be a laminated structure, i.e., a plurality of first pole pieces 111, a plurality of separators 12, and a plurality of second pole pieces 112 are stacked to form electrode assembly 10. Electrode assembly 10 formed by winding or laminating first pole piece 111, separator 12 and second pole piece 112 also has a length, width and thickness, and the length, width and thickness of electrode assembly 10 correspond to that of case 30, so that the X, Y, Z coordinate axis also applies to electrode assembly 10.

The folding of the separators at the edge positions of the electrode assembly 10 in the winding manner and the electrode assembly 10 in the lamination manner is likely to occur. The above two forming methods of the electrode assembly 10 are common in the technical field of battery manufacturing, and are not described herein again.

Referring to fig. 2, 3 and 4, in the present embodiment, the electrode assembly 10 is taken as an example of a winding structure. Along the winding direction H, the electrode assembly 10 includes a first segment a, a first bent segment B, a second segment C, and a second bent segment D, which are connected in sequence. The first adhesive member 13 adheres to the outer surface of the outermost pole piece 11 in the first segment a and/or the outer surface of the outermost pole piece 11 in the second segment C. Wherein the first segment a and the second segment C are two horizontal segments in which the electrode assembly 10 is oppositely disposed, as viewed in the second direction Y.

In the present application, the outermost layer 122 of the separator 12 refers to a portion of the separator 12 disposed on the outermost layer of the electrode assembly 10. In some embodiments, the electrode assembly 10 may be in a wound structure in which the outermost layer 122 of the separator 12 refers to a portion disposed around the tail of the separator 12 in the winding direction. In some embodiments, the electrode assembly 10 may be a laminate structure in which the outermost layer 122 of the separator 12 refers to the separator 12 disposed on the outermost layer in the third direction Z.

In the present application, the outermost pole piece 11 refers to a portion of the pole piece 11 disposed on the outermost layer of the electrode assembly 10. In some embodiments, the outermost pole piece 11 may be the first pole piece 111 or the second pole piece 112. The outer surface of the outermost pole piece 11 refers to the side of the outermost pole piece 11 facing away from the center of the electrode assembly 10. In some embodiments, the electrode assembly 10 may be in a wound configuration, with the outer surface of the outermost pole piece 11 being the side of the outermost pole piece 11 facing away from the winding center O. In some embodiments, the outer surface of the outermost pole piece 11 of the first segment a refers to the pole piece 11 of the first segment a that is distal from the second segment C, and the pole piece 11 faces away from the surface of the second segment C. The outer surface of the outermost pole piece 11 of the second segment C refers to the pole piece 11 of the second segment C far away from the first segment a, and the pole piece 11 is far away from the surface of the first segment a.

The first bending section B and the second bending section D are two arc-shaped sections oppositely arranged on the electrode assembly 10, further, the first bending section B and the second bending section D may be semi-arc-shaped, and the first bending section B and the second bending section D are respectively connected with the first section a and the second section.

In some embodiments, the first segment a and the second segment C may be straight segments, the first bent segment B and the second bent segment D may be arc segments, the tension of the isolation film 12 at the straight segment position is smaller than the tension at the arc segment position, and the first adhesive member 13 is disposed on the surface of the first segment a and/or the second segment C, so that the adhesive fixing effect is better.

Referring to fig. 5, in another embodiment, an electrode assembly 10 is taken as an example of a lamination structure. The electrode assembly 10 includes a first surface 16 and a second surface 17 in a direction in which the first pole piece 111, the separator 12, and the second pole piece 112 are laminated, i.e., in the third direction Z, and the first adhesive 13 adheres the first surface 16 and/or the second surface 17. Wherein the first surface 16 is the outer surface of the pole piece 11 at the lowermost position of the electrode assembly 10 of the lamination stack, and the second surface 17 is the outer surface of the pole piece 11 at the uppermost position of the electrode assembly 10 of the lamination stack.

It will be appreciated that the positions of the first surface 16 and the second surface 17 may be substituted.

The first bonding piece 13 is bonded to the first surface 16 and/or the second surface 17, so that the first bonding piece 13 can stably connect the isolating membrane 12 and the pole piece 11, the bonding effect is improved, and the safety of the electrochemical device 100 is further improved.

Referring to fig. 3 and 4, in the electrode assembly 10 of the winding structure, the separator 12 has an outermost portion after being wound. The outermost layer 122 of the separator 12 includes a first portion 121, the first portion 121 is disposed to extend from a portion of the separator 12 disposed between the adjacent first and

second pole pieces

111 and 112, that is, along the second direction Y, and the separator 12 disposed between the adjacent first and

second pole pieces

111 and 112 has a portion that exceeds the first and

second pole pieces

111 and 112, the portion of the separator 12 being the first portion 121. Specifically, in view of the electrode assembly 10 in a wound structure shown in fig. 3, the outermost layer 122 of the separator 12 includes a first portion 121, the first portion 121 is extended by the separator 12 disposed between the adjacent first and

second pole pieces

111 and 112, and the adjacent first and

second pole pieces

111 and 112 are the outermost first and

second pole pieces

111 and 112 in the wound electrode assembly 10. In the content shown in fig. 3, the outermost layer of the isolation film 12 exists in the first segment a, the first bent segment B, the second segment C and the second bent segment D, and because the extending distance of the tail end of the second pole piece 112 is less than the extending distance of the tail end of the first pole piece 111, the outermost layer of the isolation film 12 arranged between the adjacent first pole piece 111 and the second pole piece 112 exists in the first segment a, the first bent segment B and the second segment C, so that the first portion 121 included in the outermost layer 122 of the isolation film 12 exists in the first segment a, the first bent segment B and the second segment C.

It is understood that when the trailing ends of the first and

second pole pieces

111 and 112 extend the same distance in the electrode assembly 10 in the wound structure, the outermost layer 122 of the separator 12 includes the first portion 121 existing at the regions of the first segment a, the first bent segment B, the second segment C, and the second bent segment D.

Viewed along the third direction Z, the projection of the first portion 121 is located apart from the projections of the first and

second pole pieces

111, 112, and since the first portion 121 extends beyond the first and

second pole pieces

111, 112, the projection of the first portion 121 is also located at the same position as the projections of the first and

second pole pieces

111, 112, respectively.

Referring to fig. 2 and 3, the first adhesive member 13 includes a substrate layer 133 and a first adhesive layer 132, and the first adhesive layer 132 is disposed on a surface of the substrate layer 133. The first adhesive 13 is adhered by the first adhesive layer 132, and the first adhesive layer 132 is further adhered to the electrode assembly 10.

Specifically, the first adhesive layer 132 of the first adhesive member 13 adheres the outer surface of the outermost pole piece 11 of the electrode assembly 10 and the first portion 121. Wherein the outermost pole piece 11 of the electrode assembly 10 refers to the pole piece 11 away from the center of the electrode assembly 10. The first adhesive 13 adheres both the outermost pole piece 11 and the first portion 121, thereby connecting the outermost pole piece 11 with the first portion 121. When the electrochemical device 100 falls, the electrolyte generates impact force on the isolation film 12, but the pole piece 11 and the isolation film 12 are fixed together, so that the isolation film 12 is not easy to turn over and short circuit occurs in the electrochemical device 100.

In one embodiment, the outermost pole piece 11 of the electrode assembly 10 is the first pole piece 111. In general, the outermost separator 12 of the electrode assembly 10 is easily folded, and the separator 12 in the middle of the electrode assembly 10 is pressed, so that the folding probability is reduced compared to the outermost separator. Therefore, the outermost separator 12 is fixed, and the situation in which the separator 12 is folded back in the electrochemical device 100 can be improved. The folding of the isolation film 12 means that the isolation film 12 is bent due to the impact force of the electrolyte on the isolation film 12, and the first pole piece 111 and the second pole piece 112 separated by the isolation film 12 may contact with each other, thereby causing a short circuit in the electrochemical device 100.

It is understood that in other embodiments, the outermost pole piece 11 of the electrode assembly 10 may also be the second pole piece 112. In this embodiment, the outer surface of the outermost pole piece 11 of the electrode assembly 10 bonded by the first bonding member 13 is the outer surface of the outermost pole piece 11 at the position of the first segment a or the second segment C. Specifically, the first adhesive member 13 is adhered to the outer surface of the outermost pole piece 11 of the first segment a.

Referring to FIG. 3, in an embodiment, a region where the first adhesive member 13 is adhered to the first portion 121 is a second portion 131, and a width w of the second portion 131 is greater than or equal to 0.5 mm. Specifically, the width of the second portion 131 may be 0.6mm, 0.65mm, 0.7mm, etc. In this embodiment, the width w of the second portion 131 is the portion of the first adhesive 13 beyond the pole piece 11 when viewed along the third direction. The width w of the second portion 131 is set to be more than or equal to 0.5mm, when the first bonding piece 13 bonds the outermost pole piece 11 and the first portion 121, a part of the first bonding piece 13 is bonded on the pole piece 11, and the other part of the first bonding piece 13 is bonded on the first portion 121, so that the first bonding piece 13 is beyond the pole piece 11, the first bonding piece 13 is ensured to be bonded with the isolation film 12, and the purpose of fixing the pole piece 11 and the first portion 121 of the isolation film 12 is achieved.

In an embodiment, a projection of the second portion 131 onto the first portion 121, viewed in the third direction Z, is located within the first portion 121. I.e. along the first direction X, the first adhesive 13 extends a distance less than the distance that the first portion 121 extends, the second portion 131 being provided between the first portion 121 and the edge of the pole piece 11. The second portion 131 is limited between the first portion 121 and the pole piece 11, so that the problem that the second portion 131 interferes with the electrochemical device 100 in the packaging process of the electrochemical device 100 and enters a sealing area during packaging to affect the packaging strength of the electrochemical device 100 can be avoided. And the length of the second portion 131 is set to be smaller than that of the first portion 121, so that the encapsulation of the electrochemical device 100 is more smooth and the safety is higher.

It is understood that, in other embodiments, the projection of the second portion 131 on the first portion 121 viewed along the third direction Z may also coincide with the first portion 121, that is, the second portion 131 extends for the same distance as the first portion 121 along the first direction X, and the interference of the second portion 131 with the electrochemical device 100 may also be avoided.

Referring to fig. 6, in an embodiment, the first adhesive member 13 is further adhered to the housing 30. Specifically, the first adhesive material 13 further includes a second adhesive layer 134, and the second adhesive layer 134 and the first adhesive layer 132 are respectively provided on the opposite surfaces of the base material layer 133. The second adhesive layer 134 can be adhered to the case 30 while the first adhesive piece 13 adheres the outermost pole piece 11 and the first portion 121, so that the electrode assembly 10 and the case 30 are stably connected, the situation that the electrode assembly 10 moves relative to the case 30 when the electrochemical device 100 falls is reduced, and the safety performance of the electrochemical device 100 is improved.

Referring to fig. 7 and 8, in one embodiment, the first adhesive member 13 further adheres the winding end of the electrode assembly 10. Specifically, the electrode assembly 10 in the winding structure is formed such that the separator 12 extends beyond the first and

second pole pieces

111 and 112 and the pole piece 11 after the winding is completed. In order to fix the pole piece 11 at the tail end with the isolation film 12, a tail rubber is required. In this embodiment, the isolation film 12 and the pole piece 11 at the tail end position can be bonded by the first bonding member 13, so as to fix the isolation film 12 and the pole piece 11, and the first bonding member 13 replaces the tail end glue and has the function of the tail end glue. Here, the tail end of the electrode assembly 10 refers to a portion away from the center thereof, the center portion refers to the head end, and the head end and the tail end are opposite ends of the electrode assembly 10 that is not wound.

In this embodiment, the first adhesive 13 adheres to the outer surface of the outermost pole piece 11 of the first segment a, and the tail end of the electrode assembly 10 is disposed at the position of the second segment C, so that the first adhesive 13 also adheres to the outer surface of the outermost pole piece 11 of the second segment C. Further, in this embodiment, the first adhesive 13 is respectively disposed on the outer surface of the outermost pole piece 11 of the first segment a and the outer surface of the outermost pole piece 11 of the second segment C.

It is understood that in other embodiments, the first adhesive 13 may also be adhered to the outer surface of the outermost pole piece 11 of the first bending section B or the second bending section D, so that the first adhesive 13 forms an integral body, which facilitates the adhering of the first adhesive 13.

Referring to fig. 9, 10 and 11, if fig. 6 shows the upper surface of the electrode assembly 10, fig. 7 shows the lower surface of the electrode assembly 10. The electrode assembly 10 further includes a second adhesive 15 and first and second ends E and F, the first portion 121 is disposed at the first end E, and the second adhesive 15 adheres the first and second ends E and F and both sides of the electrode assembly 10 in the third direction.

Specifically, the first end E is an upper end position of the electrode assembly 10 in the formed winding structure, and the second end F is an upper end position of the electrode assembly 10 in the formed winding structure, as shown in upper and lower end positions in fig. 6 and 7. The second adhesive member 15 adheres the first end E and the second end F and further adheres the upper and lower opposite surfaces of the electrode assembly 10, for example, after the second adhesive member 15 adheres the upper surface of the electrode assembly 10, it extends in the thickness direction of the electrode assembly 10, and finally adheres the lower surface of the electrode assembly 10, thereby forming a U-shaped surrounding structure. The first portion 121 is disposed at the first end E, the first adhesive piece 13 is also disposed at the first end E, and the second adhesive piece 15 is adhered to a surface of the first adhesive piece 13 away from the pole piece 11, that is, the second adhesive piece 15 is adhered to an outer surface of the first adhesive piece 13, so as to ensure that a surface of the first adhesive piece 13 close to the pole piece 11 can be adhered to the isolation film 12.

Referring to fig. 9, 10 and 11, in an embodiment, a second adhesive member 15 may be disposed at a second end F opposite to the first end E, and the second adhesive member 15 at the second end F is adhered in the same manner as the second adhesive member 15 at the first end E.

By providing the second adhesive member 15 and bonding the second adhesive member 15 to the first end E and both sides of the electrode assembly 10 in the thickness direction, the separator 12 at the outermost layer of the electrode assembly 10 is fixed, and the occurrence of folding of the separator 12 at the middle position of the electrode assembly 10 is reduced.

Referring to fig. 12, fig. 12 is a top view of another embodiment of an electrode assembly 10 with a first adhesive member 13. The first adhesive 13 disposed at the first end E may be replaced by two first adhesives 13, and further, at the position of the second adhesive 15, the second adhesive 15 is adhered to the surface of the outermost pole piece 11 of the electrode assembly 10, and the first adhesives 13 are disposed at two sides of the second adhesive 15. It can be understood that the first adhesive member 13 and the second adhesive member 15 are required to adhere the separator 12 on the outermost layer of the electrode assembly 10 to ensure the connection between the separator 12 and the pole piece 11, and to reduce the occurrence of the folding of the separator 12.

Referring to fig. 9 and 10, the tab 20 may be divided into a positive tab connected to the first pole piece 111 and a negative tab connected to the second pole piece 112. There is a portion where the projection of the tab 20 and the projection of the separator 12 coincide, as viewed in the third direction Z. When the second bonding piece 15 is arranged, the tab 20 interferes with the second bonding piece 15, the isolating film 12 corresponding to the tab 20 cannot be fixed, and the turnover is easy to occur, and the first bonding piece 13 is arranged, and the first bonding piece 13 bonds the isolating film 12 corresponding to the tab 20, so that the isolating film 12 at the position is fixed, the probability of turnover of the isolating film 12 at the position is reduced, and the safety of the electrochemical device 100 is improved.

In one embodiment, the first adhesive member 13 and the second adhesive member 15 are tapes. Further, the first adhesive member 13 and the second adhesive member 15 may be one of a double-sided tape and a hot melt adhesive. It is understood that, in other embodiments, the kinds of the first adhesive member 13 and the second adhesive member 15 are not limited thereto.

Referring to fig. 1 again, the case 30 is used to accommodate the electrode assembly 10, and in the battery field, the case 30 is usually made of an aluminum plastic film. The process of disposing the electrode assembly 10 in the case 30 is common and will not be described herein.

Referring to fig. 13 and 14, an electronic device 400 including the electrochemical device 100 of any one of the above embodiments and the body 40 is further provided. The main body 40 includes a housing compartment 41, and a third adhesive member 42 is provided in the housing compartment 41, and the third adhesive member 42 adheres to the housing 30 facing the first adhesive member 13.

The electronic device 400 includes the electrochemical device 100 in the above embodiments, so that all the advantages of the electrochemical device 100 are provided, and the detailed description thereof is omitted.

The electrochemical device 100 is disposed in the housing compartment 41 and can be fixed to the housing compartment 41 by the third adhesive member 42. When the first adhesive 13 is disposed on the outermost pole piece 11 and the first portion 121 of the first segment a of the electrode assembly 10, the outer surface of the case 30 corresponding to the first adhesive 13 is adhered to the inner wall of the receiving container 41 by the third adhesive 42. When the electrochemical device 100 is bonded to the housing case 41, the outermost separator 12 corresponding to the bonding surface is folded at a high rate, and therefore, the outer surface of the case 30 corresponding to the first adhesive material 13 is bonded to the third adhesive material 42, which can improve the folding of the separator 12 in the electrochemical device 100.

In one embodiment, the electronic device 400 further includes a fourth adhesive member 50, and the fourth adhesive member 50 adheres the electrode assembly 10 to the case 30 facing the first adhesive member 13. Specifically, the fourth adhesive 50 is disposed on the outer surface of the electrode assembly 10, and the fourth adhesive 50 can be adhered to the case 30, so that the electrode assembly 10 and the case 30 can be fixed relative to each other, and the electrode assembly 10 is prevented from moving relative to the case 30 when the electrochemical device 100 is dropped. The fourth adhesive member 50 is provided to adhere the case 30 while the first adhesive member 13 can adhere the case 30, further improving the adhesive strength between the electrode assembly 10 and the case 30.

In summary, in the electrochemical device 100 and the electronic device 400 provided in the embodiments of the present application, the first adhesive 13 is disposed on the electrode assembly 10 to adhere the outer surface of the outermost pole piece 11 and the first portion 121 of the isolation film 12, so that the pole piece 11 is connected to the isolation film 12, and the isolation film 12 is bound, when the electrochemical device 100 falls, the electrolyte impacts the isolation film 12, and the isolation film 12 is not easily folded, so that the safety of the electrochemical device 100 is improved. Meanwhile, the first adhesive 13 can be adhered to the case 30, so that the stability of connection between the electrode assembly 10 and the case 30 is improved, and the relative movement between the electrode assembly 10 and the case 30 is reduced.

In addition, one of ordinary skill in the art should recognize that the above embodiments are illustrative only, and not limiting, and that suitable modifications and variations of the above embodiments are within the scope of the disclosure.

Claims

1. An electrochemical device comprising an electrode assembly and a case accommodating the electrode assembly, wherein the electrode assembly comprises:

the pole piece comprises a first pole piece and a second pole piece with opposite polarities, and the first pole piece and the second pole piece are arranged in a stacked mode;

a separator for separating the first and second pole pieces, an outermost layer of the separator including a first portion, a projection of the first portion being disposed apart from a projection of the pole pieces in a thickness direction of the electrode assembly, the first portion being disposed to extend from a portion of the separator disposed between the adjacent first and second pole pieces;

and a first adhesive member adhering the outer surface of the outermost pole piece of the electrode assembly and the first portion.

2. The electrochemical device according to claim 1, wherein the region where the first adhesive member is adhered to the first portion is a second portion having a width w ≧ 0.5 mm.

3. The electrochemical device of claim 2, wherein a projection of the second portion onto the first portion is located within the first portion.

4. The electrochemical device of claim 1, wherein the first adhesive member further adheres to the case.

5. The electrochemical device according to claim 1, wherein the electrode assembly is a wound structure, and the first pole piece, the second pole piece, and the separator are stacked and wound.

6. The electrochemical device according to claim 5, wherein the electrode assembly includes a first segment, a first bent segment, a second segment, and a second bent segment connected in sequence in a winding direction, and the first adhesive member adheres to an outer surface of an outermost pole piece of the first segment and/or an outer surface of an outermost pole piece of the second segment.

7. The electrochemical device according to claim 5, wherein the first adhesive member further adheres a winding end of the electrode assembly.

8. The electrochemical device according to claim 1, wherein the electrode assembly is a laminated structure, and the first pole piece, the second pole piece, and the separator are stacked.

9. The electrochemical device according to claim 8, wherein the electrode assembly includes a first surface and a second surface in a thickness direction of the electrode assembly, and the first adhesive adheres the first surface and/or the second surface.

10. The electrochemical device according to claim 1, wherein the electrode assembly further comprises a second adhesive and a first end portion, the first portion is provided at the first end portion, and the second adhesive adheres the first end portion and both sides of the electrode assembly in a thickness direction.

11. The electrochemical device of claim 10, wherein the second adhesive bonds a surface of the first adhesive facing away from the pole piece.

12. An electronic device comprising a body and the electrochemical device according to any one of claims 1 to 11, wherein the body comprises a housing compartment, and a third adhesive member is provided on an inner wall of the housing compartment, and the third adhesive member adheres to the housing facing the first adhesive member.

13. The electronic device according to claim 12, wherein the electronic device further comprises a fourth adhesive member that adheres the electrode assembly to the case where the first adhesive member faces.