WO2022228193A1

WO2022228193A1 - Energy storage device and electronic apparatus

Info

Publication number: WO2022228193A1
Application number: PCT/CN2022/087535
Authority: WO
Inventors: 陈志勇
Original assignee: 广东微电新能源有限公司
Priority date: 2021-04-28
Filing date: 2022-04-19
Publication date: 2022-11-03
Also published as: CN214672732U

Abstract

An energy storage device and an electronic apparatus. The energy storage device comprises a positive electrode sheet (1), a negative electrode sheet (2) and two isolation films (3), wherein one of the positive electrode sheet (1) and the negative electrode sheet (2) is located between the two isolation films (3), and the other is located on an outer side of one of the isolation films (3); the positive electrode sheet (1), the negative electrode sheet (2) and the two isolation films (3) form a spiral wound structure (6), and a through hole (60) is formed in the middle of the wound structure (6); and at the starting end of the wound structure (6), at least one of the isolation films (3) extends into the through hole (60).

Description

Energy storage devices and electronic equipment

This disclosure claims the priority of a Chinese patent application with the application number 202120909496.X and the application title "Energy Storage Device and Electronic Equipment", which was filed with the China Patent Office on April 28, 2021, the entire contents of which are incorporated herein by reference. middle.

technical field

The present invention relates to the technical field of energy storage, and more particularly, to an energy storage device and electronic equipment.

Background technique

The energy storage device is used to provide energy for the equipment, and the safety of the energy storage device affects the safe use of the equipment. The arrangement of the positive electrode sheet and the negative electrode sheet in the energy storage device affects the safety of the energy storage device, and the insulation effect between the positive electrode sheet and the negative electrode sheet is insufficient, which easily leads to the problem of insufficient safety of the energy storage device. Therefore, it is necessary to provide a new technical solution to solve the above problems.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an energy storage device and an electronic device.

According to a first aspect of the present invention, an energy storage device is provided, the energy storage device comprising a positive electrode sheet, a negative electrode sheet and two separators;

One of the positive electrode sheet and the negative electrode sheet is located between the two separators, and the other is positioned outside one of the separators, and the positive electrode sheet, the negative electrode sheet and the two separators form a spiral roll a winding structure, and a through hole is formed in the middle of the winding structure;

At the beginning of the rolled structure, at least one of the isolation films extends within the through hole.

Optionally, the portion of the isolation film extending into the through hole is in contact with the hole wall of the through hole.

Optionally, the positive electrode sheet and/or the negative electrode sheet has a first connection part;

It also includes a tab, the tab corresponds to the first connection part one-to-one, the tab has a second connection part, the second connection part is electrically connected with the first connection part, the tab bend and lean towards the end of the coiled structure;

It also includes an insulating layer, the insulating layer is in one-to-one correspondence with the tabs, the insulating layer covers the side of the tabs that is close to the end portion, and extends to cover the first connection portion and the second connecting portion.

Optionally, it further includes a first tab and a second tab, the first tab is electrically connected to the positive electrode sheet, and the second tab is electrically connected to the negative electrode tab;

The first tab is bent and approached to one end of the winding structure, the second tab is bent and approached to the other end of the winding structure, the first tab and the second tab are The included angle between the projections of the tabs on the cross section of the winding structure is 0°-90°.

Optionally, it also includes a casing, the winding structure is arranged in the casing, the casing is welded with the tab, and the welding position has two welding points, and the space between the two welding points is The distance is 0.5mm-5mm.

Optionally, along the axial direction of the winding structure, one of the solder joints is located in the projection of the through hole.

Optionally, it also includes a casing, the casing includes an inner casing and an outer casing, the inner casing and the outer casing are both cylindrical structures with one end open, and the outer casing is sleeved outside the inner casing to seal the outer casing. the cylindrical structure;

A sealing ring is arranged between the inner casing and the outer casing, and the width of the opening of the sealing ring exposing the outer casing is greater than 0.5 mm.

Optionally, the inner shell includes a top plate and a first side wall, and the first side wall is disposed around the top plate to form a cylindrical structure;

the housing includes a bottom plate and a second side wall, the second side wall is disposed around the bottom plate to form a cylindrical structure;

The second side wall is sleeved outside the first side wall, the sealing ring is arranged between the second side wall and the first side wall, and the first side wall and the second side wall are The area of overlap between the side walls is 10%-90%.

Optionally, the two isolation films are folded from a single isolation film.

Optionally, in the axial direction of the winding structure, the size of the negative electrode sheet at each end of the winding structure is larger than the size of the positive electrode sheet by more than 0.1 mm.

Optionally, in the axial direction of the winding structure, the size of the separator at each end of the winding structure is larger than the size of the negative electrode sheet by more than 0.5 mm.

Optionally, the cross-section of the portion of the isolation film located in the through hole is linear or S-shaped.

Optionally, the portion of the isolation membrane located in the through hole extends along the radial direction of the through hole.

According to a second aspect of the present invention, there is provided an electronic device including the energy storage device according to any one of the first aspect.

One technical effect of the present invention is that, by extending at least one isolation film into the through hole at the starting end of the winding structure, the isolation film protruding into the through hole helps to absorb the electrolyte and extends into the isolation of the through hole. The membrane part makes the beginning of the winding structure wrap the positive electrode sheet and the negative electrode sheet more completely, and can prevent the positive electrode sheet and the negative electrode sheet from being exposed. This structure improves the insulating effect of the separator at the beginning end of the winding structure.

Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.

Description of drawings

The accompanying drawings, which form a part of the specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

FIG. 1 is a cross-sectional view of a winding core structure in one embodiment of the present disclosure.

FIG. 2 is a schematic structural diagram of a winding core structure in an embodiment of the present disclosure.

3 is a schematic diagram of an end face of a winding core structure in an embodiment of the present disclosure.

4 is a schematic structural diagram of a side surface on which the first tab is disposed on the positive electrode sheet according to an embodiment of the present disclosure.

FIG. 5 is a schematic structural diagram of another side of FIG. 4 .

FIG. 6 is a schematic structural diagram of a winding core structure in another embodiment of the present disclosure.

FIG. 7 is a schematic structural diagram of a welding point where a shell of an energy storage device and a tab are welded according to an embodiment of the present disclosure.

8 is a cross-sectional view of an energy storage device in one embodiment of the present disclosure.

Description of reference numerals: 1. Positive electrode sheet; 10. First connecting part; 2. Negative electrode sheet; 3. Separator; 40. Second connecting part; 41. First tab; 42, Second tab; Insulation layer; 6, winding structure; 60, through hole; 7, shell; 71, inner shell; 72, outer shell; 8, solder joint; 9, sealing ring.

Detailed ways

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques and devices should be considered part of the specification.

In all examples shown and discussed herein, any specific values should be construed as illustrative only and not limiting. Accordingly, other instances of the exemplary embodiment may have different values.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further discussion in subsequent figures.

According to an embodiment of the present disclosure, as shown in FIGS. 1-3 , an energy storage device is provided, and the energy storage device includes a positive electrode sheet 1 , a negative electrode sheet 2 and two separators 3 .

One of the positive electrode sheet 1 and the negative electrode sheet 2 is located between the two separators 3, and the other is located outside one of the separators 3. The positive electrode sheet 1, the negative electrode sheet 2 and the two separators are separated from each other. The film 3 forms a helical winding structure 6 , and a through hole 60 is formed in the middle of the winding structure 6 .

At the beginning of the winding structure 6 , at least one of the isolation films 3 extends into the through hole 60 .

In this embodiment, the separator 3 forms insulation between the positive electrode sheet 1 and the negative electrode sheet 2, and can allow the passage of ions for charging and discharging. For example, the separator 3 allows lithium ions to pass therethrough. The two separators 3 can form insulation between the positive electrode sheet 1 and the negative electrode sheet 2 . In the structure before winding, the positive electrode sheet 1 , the negative electrode sheet 2 and the separator 3 are laminated together. One of the separators 3 is located between the positive electrode sheet 1 and the negative electrode sheet 2 to form isolation on the inner side. The other separator 3 is outside the positive electrode sheet 1 or the negative electrode sheet 2 . After the winding structure is formed, the outer sides of the positive electrode sheet 1 and the negative electrode sheet 2 when they are stacked and not wound are wound together, and the separator 3 located on the outer side is between the outer sides when the positive electrode sheet 1 and the negative electrode sheet 2 are stacked and not wound form isolation.

After the winding structure 6 is formed, a through hole 60 is formed in the middle, and a part of the hole wall of the through hole 60 is formed at the starting end of the winding.

At least one isolation film 3 extends into the through hole 60 by leaving a part of the isolation film 3 at the starting end of the winding structure 6 . The separator 3 located in the through hole 60 is not pressed by the positive electrode sheet 1 and the negative electrode sheet 2 . When the cell is in the electrolyte, the separator 3 extending into the through hole 60 helps to absorb the electrolyte.

The part of the separator 3 extending into the through hole 60 makes the beginning of the winding structure 6 wrap the positive electrode sheet 1 and the negative electrode sheet 2 more completely, which can prevent the positive electrode sheet 1 and the negative electrode sheet 2 from being exposed. Such a structure improves the insulating effect of the isolation film 3 at the beginning of the winding structure 6, so as to improve the safety of the energy storage device.

Optionally, the end of the isolation film 3 is in contact with the hole wall of the through hole 60 .

The portion of the isolation film 3 extending into the through hole 60 is in contact with the hole wall of the through hole 60 , which can further form an insulating effect. For example, it is possible to avoid the short circuit problem that occurs when the start ends of the positive electrode sheet 1 and the negative electrode sheet 2 protrude into the through holes 60 . The end of the isolation film 3 is in contact with the hole wall of the through hole 60 , which effectively isolates the through hole 60 and forms two insulating spaces separated by the isolation film 3 . The isolation film 3 forms insulation between the two separated spaces, which further improves the insulation effect of the winding structure 6 and increases the safety of the energy storage device.

Optionally, the two isolation films 3 are folded from a single isolation film.

For example, two separators 3 are formed by folding one separator 3 in half, and the positive electrode sheet 1 or the negative electrode sheet 2 located between the two separators 3 is sandwiched by the folded separators 3 .

One isolation film 3 is folded in half to form a structure of two isolation films 3 , which can increase the structural strength of the winding structure 6 . The strength of the insulating structure formed by the separator 3 for the positive electrode sheet 1 and the negative electrode sheet 2 is improved, and the overall structural strength of the winding structure 6 is improved at the same time.

For example, a single isolation film 3 is folded in half at the position of the beginning or the end when the winding structure 6 is wound, which can effectively form an insulating effect at the end. When not being wound, the separator 3 may be folded in half at the position of one side of the positive electrode sheet 1 or the negative electrode sheet 2 . The positive electrode sheet 1 and the negative electrode sheet 2 have two sides connecting the beginning and the end, and two sides connecting the beginning and the end.

For example, the single sheet of separator 3 is folded in half along the long side parallel to itself or perpendicular to the long side. The long side is the side in the longitudinal direction of the separator 3 .

Optionally, the winding structure 6 is wound with double needles, and the winding needles are withdrawn after the winding structure 6 is formed. The isolation film 3 extending in the through hole 60 is sandwiched between the two winding needles, so that part of the structure of the isolation film 3 can be effectively maintained at the protruding end during winding, so as to form the winding structure 6 and then remain in the through hole 60.

It is also possible to use single-needle winding, which is wound to form the winding structure 6 and then pulled out of the winding needle. The position of the part where the separator 3 protrudes into the through hole 60 can be adjusted according to the positions of the ends of the positive electrode sheet 1 and the negative electrode sheet 2 in the through hole 60 .

Optionally, the cross section of the part of the isolation film 3 located in the through hole 60 is linear or S-shaped.

The partial structure of the isolation film 3 in the through hole 60 may be linearly extended, or the partial structure of the extended isolation film 3 may be S-shaped. It can be adjusted according to the actual structure and requirements in the through hole 60 . The portions of the isolation film 3 extending into the through holes 60 have different shapes, and the different shapes provide different surface areas. Different shapes of the separator 3 have different contact areas with the electrolyte and have different absorption effects.

Optionally, the portion of the isolation film 3 located in the through hole 60 extends along the radial direction of the through hole 60 .

The isolation film 3 extends radially inside the through hole 60 and can isolate the through hole 60 into two uniform parts. In this way, the spaces on both sides of the separator 3 can have the same accommodation capacity, which satisfies the available space for the positive electrode sheet 1 or the negative electrode sheet 2 to protrude into the through hole 60 .

The through holes 60 help the electrolyte in the energy storage device to enter, increase the contact area between the electrolyte and the positive electrode sheet 1 and the negative electrode sheet 2, and improve the charging and discharging capability.

Optionally, the portion of the isolation diaphragm 3 extending into the through hole 60 has a size in the radial direction of the through hole 60 larger than the radial size of the through hole 60 .

In this embodiment, the size of the portion of the isolation film 3 extending into the through hole 60 is larger with respect to the radial dimension of the through hole 60 . When the end of the isolation film 3 is in contact with the inner wall of the through hole 60 , the isolation film 3 can form an effective isolation in the through hole 60 to increase the insulating effect. For example, the separator 3 extends from the beginning of the winding structure 6 into the through hole 60 , and the ends of the positive electrode sheet 1 and the negative electrode sheet 2 on both sides of the separator 3 are located at the two ends of the structure of the separator 3 extending into the through hole 60 . side.

The size of the separator 3 is larger, and when the separator 3 is set in different shapes or different states, two spaces that are insulated from each other can be effectively formed at the beginning to form an effective isolation between the beginnings of the positive electrode sheet 1 and the negative electrode sheet 2 . The existence of a gap between the two sides of the isolation film 3 isolated in the through hole 60 is avoided, and the insulating effect is increased.

In one embodiment, the positive electrode sheet 1 and/or the negative electrode sheet 2 has a first connection portion;

It also includes a tab, the tab corresponds to the first connection part one-to-one, the tab has a second connection part, the second connection part is electrically connected with the first connection part, the tab Bend and abut the end of the coiled structure 6 .

It also includes an insulating layer 5, the insulating layer 5 corresponds to the tabs one-to-one, the insulating layer 5 covers the side of the tab that is close to the end, and extends to cover the first tab. a connecting part and the second connecting part.

In this embodiment, the insulating layer 5 forms insulation between the end portion of the winding structure 6 and the tab, and extends to cover the first connection portion and the second connection portion, so as to be disposed on the positive electrode sheet 1 or the negative electrode sheet 2 The location of the tabs creates an insulating effect.

The insulating layer 5 covers from one side of the tab, and covers the position where the tab is connected to the positive electrode sheet 1 or the negative electrode sheet 2 . That is, it extends from one side of the tab close to the end of the winding structure 6 to the other side. Compared with the prior art in which insulation is provided on both sides of the tab, the single insulating layer 5 in this embodiment is more convenient and simple. In addition, the single insulating layer 5 can cover the end of the tab and the positive electrode sheet 1 or the negative electrode sheet 2 connected to the tab. The insulation effect is improved. The insulating layer 5 only needs to be provided once, which reduces the process of providing the insulating layer 5 and improves the efficiency.

As shown in FIG. 4 and FIG. 5 , the first tab 41 is provided on the positive electrode sheet 1 as an example for illustration. The first connection part 10 on the positive electrode sheet 1 is connected with the second connection part 40 on the first tab 41 , for example, an electrical connection is formed by a welding machine.

The insulating layer 5 starts to coat from one side of the first tab 41 , and extends through the second connecting portion 40 , then passes through the position where the first connecting portion 10 and the second connecting portion 40 are connected, and bypasses the first tab 41 . The end portion finally covers the first connecting portion 10 . The side where the insulating layer 5 begins to cover is the side that is bent toward the end of the winding structure 6 .

In this example, the tab is on the side facing the outside of the winding structure 6 with respect to the connected positive electrode sheet 1 or the negative electrode sheet 2 . The tabs may also be located on the inner side with respect to the connected positive electrode sheet 1 or negative electrode sheet 2 .

In one embodiment, as shown in FIG. 6 , it further includes a first tab 41 and a second tab 42 , the first tab 41 is electrically connected to the positive electrode sheet 1 , and the second tab 42 is electrically connected to the positive electrode sheet 1 . The negative electrode sheet 2 is electrically connected.

The first tabs 41 are bent and approach one end of the winding structure 6 , the second tabs 42 are bent and approach the other end of the winding structure 6 , the first tabs 41 The included angle with the projection of the second tab 42 on the cross section of the winding structure 6 is 0°-90°.

In this embodiment, the first tab 41 is disposed at the end of the positive electrode sheet 1 , and the second tab 42 is disposed at the end of the negative electrode sheet 2 . After the winding structure 6 is formed, the negative electrode sheet 2 is located at an outer layer relative to the positive electrode sheet 1, and the negative electrode sheet 2 needs to be wound for more distance relative to the positive electrode sheet 1 at the end, so that the charging and discharging function of the formed cell is better. .

The included angle between the projections of the first tab 41 and the second tab 42 on the cross section of the winding structure 6 is 0°-90°, that is, the end of the negative electrode sheet 2 is wound relative to the end of the positive electrode sheet 1 The outer layer of the structure 6 is wound by 0°-90°. In this way, the number of negative electrode sheets 2 in the outermost layer is more than that of positive electrode sheets 1 , and at the same time, there is no need to wrap more negative electrode sheets 2 in the circumferential direction, which saves materials and reduces costs.

In one embodiment, as shown in FIG. 7 , the energy storage device further includes a casing 7 , the winding structure 6 is arranged in the casing 7 , and the casing 7 is welded with the tabs by welding. There are two solder joints 8 in the position of , and the distance between the two solder joints 8 is 0.5mm-5mm.

In this embodiment, the tabs and the housing 7 are fixed and electrically connected by welding. For example, it is fixed and electrically connected by means of two-pin soldering. The distance between the two welding points 8 is 0.5mm-5mm, which can not only meet the welding requirements, but also prevent the welding position from being separated from the tabs, so as to avoid virtual welding.

For example, when the first tab 41 on the positive electrode sheet 1 and the casing 7 and the second tab 42 on the negative electrode sheet 2 and the casing 7 are welded, the distance between the two welding points 8 is 0.5mm-5mm .

Optionally, along the axial direction of the winding structure 6 , one of the solder joints 8 is located in the projection of the through hole 60 . The solder joint 8 located in the projection of the through hole 60 serves as the center solder joint of the welding tab and the shell 7 to limit the position of the solder joint during soldering.

In this embodiment, along the axial direction of the winding structure 6 , the projection of the through hole 60 will have a position that overlaps with the housing 7 and the tabs. One of the solder joints 8 is located within this projection, which can define the position of the two solder joints 8 . It is avoided that the welding point 8 is separated from the position where the casing 7 and the tab overlap, thereby avoiding the existence of a virtual welding welding point 8 at the welding position.

In one embodiment, as shown in FIG. 8 , the energy storage device further includes a casing 7 , the casing 7 includes an inner casing 71 and an outer casing 72 , and both the inner casing 71 and the outer casing 72 are open at one end. In the cylindrical structure, the outer shell 72 is sleeved outside the inner shell 71 to seal the cylindrical structure.

A sealing ring 9 is disposed between the inner casing 71 and the outer casing 72 , and the width of the sealing ring 9 exposing the opening of the outer casing 72 is greater than 0.5 mm.

In this embodiment, the sealing ring 9 forms a seal and insulation between the inner casing 71 and the outer casing 72 . The width of the opening of the sealing ring 9 exposing the outer casing 72 is made larger than 0.5 mm, which can effectively prevent the outer casing 72 from contacting the inner casing 71 and improve the insulation effect.

In one embodiment, the inner shell 71 includes a top plate and a first side wall, and the first side wall is disposed around the top plate to form a cylindrical structure.

The housing 72 includes a bottom plate and a second side wall disposed around the bottom plate to form a cylindrical structure.

The second side wall is sleeved outside the first side wall, the sealing ring 9 is arranged between the second side wall and the first side wall, and the first side wall is connected to the first side wall. The overlapping area between the two side walls accounts for 10%-90%.

In this embodiment, the first side wall and the second side wall are the side walls of the cylindrical structure. The overlapping portion of the first side wall and the second side wall determines the area of the area where the inner shell 71 and the outer shell 72 are connected. By setting the ratio of the overlapping area between the first side wall and the second side wall to 10%-90%, the structural strength of the outer casing 72 and the inner casing 71 can be effectively guaranteed, and the sealing ring 9 can be ensured in the first The sealing effect between one side wall and the second side wall.

Optionally, the first tab 41 connected to the positive electrode sheet 1 is electrically connected to one of the top plate on the inner casing 71 or the bottom plate on the outer casing 72 . The second tab 42 on the negative electrode sheet 2 is electrically connected to the other of the top plate on the inner casing 71 or the bottom plate on the outer casing 72 .

In one embodiment, as shown in FIG. 1 , in the axial direction of the winding structure 6 , the size of the negative electrode sheet 2 at each end of the winding structure 6 is larger than the size of the positive electrode sheet 1 by 0.1 mm or more.

In this embodiment, the size of the negative electrode sheet 2 at the end of the winding structure 6 is larger than that of the positive electrode sheet 1, so that the negative electrode sheet 2 has more volume and meets the demand for the consumption of the negative electrode sheet 2 by charging and discharging.

As shown in FIG. 1 , at the upper and lower ends of the winding structure 6 , the negative electrode sheet 2 is higher than the positive electrode sheet by 0.1 mm or more, so as to meet the consumption demand of the negative electrode sheet 2 by the charging and discharging of the energy storage device.

In one embodiment, as shown in FIG. 1 , in the axial direction of the winding structure 6 , the size of the separator 3 at each end of the winding structure 6 is larger than the size of the negative electrode sheet 2 by 0.5 mm or more.

As shown in FIG. 1 , at the upper and lower ends of the winding structure 6 , the separator 3 is higher than the negative electrode sheet by more than 0.5 mm, so that the separator 3 can effectively separate the positive electrode sheet 1 and the negative electrode sheet 2 at the end of the winding structure 6 . form insulation.

According to another embodiment of the present disclosure, there is provided an electronic device including the energy storage device according to any one of the above embodiments.

The energy storage device in the above embodiment is used for electronic equipment, which improves the safety of electronic equipment. For example, the electronic equipment may be a mobile phone, a tablet computer, an earphone, or other equipment that requires an energy storage device to provide energy.

The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Repeat.

While some specific embodiments of the present invention have been described in detail by way of example, those skilled in the art will appreciate that the above examples are provided for illustration only and not for the purpose of limiting the scope of the invention. Those skilled in the art will appreciate that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the invention is defined by the appended claims.

Claims

An energy storage device, characterized in that it comprises a positive electrode sheet, a negative electrode sheet and two separators;

One of the positive electrode sheet and the negative electrode sheet is located between the two separators, and the other is positioned outside one of the separators, and the positive electrode sheet, the negative electrode sheet and the two separators form a spiral roll a winding structure, and a through hole is formed in the middle of the winding structure;

At the beginning of the rolled structure, at least one of the isolation films extends within the through hole.
The energy storage device according to claim 1, wherein a portion of the isolation film extending into the through hole is in contact with a hole wall of the through hole.
The energy storage device according to claim 1 or 2, wherein the positive electrode sheet and/or the negative electrode sheet has a first connection part;

It also includes a tab, the tab corresponds to the first connection part one-to-one, the tab has a second connection part, the second connection part is electrically connected with the first connection part, and the tab bend and lean towards the end of the coiled structure;

It also includes an insulating layer, the insulating layer is in one-to-one correspondence with the tabs, the insulating layer covers the side of the tabs that is close to the end portion, and extends to cover the first connection portion and the second connecting portion.
The energy storage device according to any one of claims 1-3, further comprising a first tab and a second tab, the first tab is electrically connected to the positive electrode sheet, and the second tab is The tab is electrically connected to the negative electrode sheet;

The first tab is bent and approached to one end of the winding structure, the second tab is bent and approached to the other end of the winding structure, the first tab and the second tab are The included angle between the projections of the tabs on the cross section of the winding structure is 0°-90°.
The energy storage device according to any one of claims 1-4, further comprising a casing, the winding structure is arranged in the casing, the casing and the tab are welded, and the welded The location has two solder joints, and the distance between the two solder joints is 0.5mm-5mm.
The energy storage device according to any one of claims 1-5, characterized in that, along the axial direction of the winding structure, one of the solder joints is located in the projection of the through hole.
The energy storage device according to any one of claims 1-6, further comprising a casing, the casing comprising an inner casing and an outer casing, both the inner casing and the outer casing are cylindrical with an open end structure, the outer shell is sleeved outside the inner shell to seal the cylindrical structure;

A sealing ring is arranged between the inner casing and the outer casing, and the width of the opening of the sealing ring exposing the outer casing is greater than 0.5 mm.
The energy storage device according to any one of claims 1-7, wherein the inner case comprises a top plate and a first side wall, and the first side wall is arranged around the top plate to form a cylindrical structure;

the housing includes a bottom plate and a second side wall, the second side wall is disposed around the bottom plate to form a cylindrical structure;

The second side wall is sleeved outside the first side wall, the sealing ring is arranged between the second side wall and the first side wall, and the first side wall and the second side wall are The area of overlap between the side walls is 10%-90%.
The energy storage device according to any one of claims 1-8, wherein the two isolation films are formed by folding a single isolation film.
The energy storage device according to any one of claims 1-9, wherein in the axial direction of the winding structure, the size of the negative electrode sheet at each end of the winding structure is larger than that of the positive electrode The size of the sheet is 0.1 mm or more.
The energy storage device according to any one of claims 1-10, wherein in the axial direction of the winding structure, the size of the separator at each end of the winding structure is larger than that of the negative electrode The size of the sheet is 0.5mm or more.
The energy storage device according to any one of claims 1-11, characterized in that, the cross section of the part of the isolation membrane located in the through hole is linear or S-shaped.
The energy storage device according to any one of claims 1-12, wherein a portion of the isolation membrane located in the through hole extends along a radial direction of the through hole.
An electronic device, characterized by comprising the energy storage device according to any one of claims 1-13.