CN215644618U

CN215644618U - Cylindrical battery core, secondary battery and automobile

Info

Publication number: CN215644618U
Application number: CN202121199147.XU
Authority: CN
Inventors: 张卫龙; 张五堂; 熊亮; 周中心
Original assignee: Shanghai Lanjun New Energy Technology Co Ltd
Current assignee: Shanghai Lanjun New Energy Technology Co Ltd
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2022-01-25
Anticipated expiration: 2031-05-31

Abstract

The embodiment of the utility model provides a cylindrical battery cell, a secondary battery and an automobile, and relates to the field of batteries. The cylindrical battery cell comprises a first pole piece, a second pole piece, a first diaphragm and a second diaphragm; the first pole piece comprises a first body and a first slurry layer, and the second pole piece comprises a second body and a second slurry layer; the first body is provided with a first winding section and a first empty foil section, and the first slurry layer is coated on two opposite side surfaces of the first body of the first winding section; the second body is provided with a second winding section and a second empty foil section, the second slurry layer is coated on two opposite side faces of the second body of the second winding section, the first winding section, the second diaphragm, the second winding section and the second diaphragm are wound into a column shape, the second diaphragm is located on the outermost layer of the cylindrical battery cell, and the first diaphragm extends to the first empty foil section and the second empty foil section from the first winding section and the second winding section. The embodiment of the utility model can ensure the volume energy density of the battery and improve the safety of the battery.

Description

Cylindrical battery core, secondary battery and automobile

Technical Field

The utility model relates to the field of batteries, in particular to a cylindrical battery cell, a secondary battery and an automobile.

Background

The lithium ion battery has the characteristics of large capacity, long service life, high safety performance and the like, but the pole piece of the battery can be broken in the working process due to the fact that the inside and the outside of the winding core are loose and tight, and the qualified rate of the battery core is low; the 'cavity phenomenon' of the inner part of the winding core after the core of the winding core is pulled after winding can cause the collapse of the inner structure and the polarization of the battery due to the volume effect of the negative pole piece in the working process of the battery, and the service performance of the battery is reduced.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a cylindrical battery cell, a secondary battery and an automobile, which can ensure the volume energy density of the battery and improve the service performance and safety of the battery.

The embodiment of the utility model is realized by the following steps:

in a first aspect, the utility model provides a cylindrical battery cell, which comprises a first pole piece, a second pole piece, a first diaphragm and a second diaphragm;

the first pole piece, the first diaphragm, the second pole piece and the second diaphragm are sequentially stacked and wound into a column shape from inside to outside, the second diaphragm is located on the outermost layer of the cylindrical battery cell, the first pole piece comprises a first body and a first slurry layer, and the second pole piece comprises a second body and a second slurry layer;

the first body is provided with a first winding section and a first empty foil section in the length direction, and the first slurry layer is coated on two opposite sides of the first body of the first winding section; the second body is provided with a second winding section and a second empty foil section in the length direction, the second slurry layer is coated on two opposite sides of the second body of the second winding section, and the first winding section, the second membrane, the second winding section and the second membrane are wound.

In an optional embodiment, the first body is a copper foil, and the first slurry layer is a negative slurry coating.

In an alternative embodiment, the second body is an aluminum foil, and the second slurry layer is a positive slurry coating.

In an alternative embodiment, the length of the first empty foil section is the length of the perimeter of the outermost ring of the second diaphragm, and the first empty foil section can completely cover the outermost ring of the second diaphragm.

In an alternative embodiment, the length of the second empty foil section is the length of the perimeter of the outermost ring of the second diaphragm, and the second empty foil section can completely cover the outermost ring of the second diaphragm.

In an alternative embodiment, the first membrane has a wound membrane section and a wrapped membrane section in the length direction, the wound membrane section being windable into a cylindrical shape with the first wound section, the second wound section and the second membrane, the wrapped membrane section being located between the first empty foil section and the second empty foil section.

In an alternative embodiment, the length of the wrapped membrane segment is greater than the length of the first empty foil segment and greater than the length of the second empty foil segment.

In an alternative embodiment, the length of the wrapped membrane segment is 2-5 mm longer than the first or second empty foil segment.

In a second aspect, the present invention provides a secondary battery comprising a cylindrical cell as described in any of the previous embodiments.

In a third aspect, the present invention provides an automobile including the secondary battery according to the foregoing embodiment.

The embodiment of the utility model provides a cylindrical battery cell, a secondary battery and an automobile: the first pole piece, the first diaphragm, the second pole piece and the second diaphragm are wound into a column shape, so that a cylindrical battery cell is formed. And during winding, the second diaphragm, the second pole piece, the first diaphragm and the first pole piece are wound around the winding needle in and out according to the sequence that the second diaphragm, the second pole piece, the first diaphragm and the first pole piece are arranged from outside to inside. A first diaphragm is arranged between the first pole piece and the second pole piece and plays the roles of separation and insulation. The first diaphragm between the first pole piece and the second pole piece can be wound together at a very small distance, so that high volume energy density of the battery can be realized, the high volume energy density can bear more energy in a limited space, and the battery endurance is further improved. In the embodiment of the utility model, in the first empty foil section and the second empty foil section, the first diaphragm can separate and insulate the first empty foil section and the second empty foil section, when the battery cell is punctured by an external sharp conductor, the first diaphragm between the first empty foil section and the second empty foil section is punctured, and the first empty foil section is conducted with the second hole foil section, so that the battery cell is rapidly short-circuited; meanwhile, the short-circuit current can be shunted, so that the electric quantity in the battery core is discharged, the battery is prevented from being ignited, and the safety of the battery is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a cylindrical battery cell according to an embodiment of the present invention;

fig. 2 is a schematic diagram of the cylindrical cell in fig. 1 during manufacturing;

fig. 3 is a schematic diagram of the cylindrical cell of fig. 1 during manufacture;

fig. 4 is a schematic diagram of a first pole piece, a second pole piece, and a first diaphragm in a cylindrical battery cell according to an embodiment of the present invention.

Icon: 100-cylindrical cells; 110-a first pole piece; 111-a first winding section; 112-a first empty foil section; 120-a second pole piece; 121-a second winding section; 122-a second empty foil section; 130-a first membrane; 131-winding the membrane segment; 132-a wrapped membrane segment; 140-second diaphragm.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element to which the description refers must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used only for descriptive purposes and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical" and the like do not imply that the components are required to be absolutely horizontal or pendant, but rather may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1 to 4, an embodiment of the utility model provides a cylindrical battery cell 100. The cylindrical battery core 100 can ensure the volume energy density of the battery and improve the service performance and safety of the battery.

In the embodiment of the present invention, the cylindrical battery cell 100 includes a first pole piece 110, a second pole piece 120, a first diaphragm 130, and a second diaphragm 140; the first pole piece 110, the first diaphragm 130, the second pole piece 120 and the second diaphragm 140 are sequentially stacked and wound into a column shape from inside to outside, the second diaphragm 140 is located on the outermost layer of the cylindrical battery cell 100, the first pole piece 110 comprises a first body and a first slurry layer, and the second pole piece 120 comprises a second body and a second slurry layer; the first body has a first winding section 111 and a first empty foil section 112 in the length direction, and a first slurry layer is coated on two opposite sides of the first body of the first winding section 111; the second body has a second winding section 121 and a second empty foil section 122 in a length direction, a second slurry layer is coated on opposite sides of the second body of the second winding section 121, and the first winding section 111, the second separator 140, the second winding section 121, and the second separator 140 are wound.

It should be noted that, in the embodiment of the present invention, the first pole piece 110, the first separator 130, the second pole piece 120, and the second separator 140 are wound into a cylindrical shape, so as to form the cylindrical battery cell 100. Referring to fig. 2 and 3, during winding, the second separator 140, the second pole piece 120, the first separator 130 and the first pole piece 110 are wound around the winding needle in and out order from outside to inside. In the embodiment of the present invention, the first separator 130 is disposed between the first pole piece 110 and the second pole piece 120, so as to perform the functions of separation and insulation. The first separator 130 between the first pole piece 110 and the second pole piece 120 can be wound together with a very small distance, so that a high volumetric energy density of the battery can be achieved, the high volumetric energy density can carry more energy in a limited space, and further, the battery endurance can be improved.

Referring to fig. 4, it should be noted that, in the embodiment of the present invention, the first body of the first pole piece 110 has a first winding section 111 and a first empty foil section 112 in the length direction, the first slurry coating is coated on the first winding section 111, and the first winding section 111 participates in winding, while the first empty foil section 112 does not participate in winding; likewise, for the second pole piece 120, the second body thereof has a second winding segment 121 and a second empty foil segment 122 in the length direction, the second paste layer is coated on the second winding segment 121, and the second winding segment 121 participates in winding, while the first empty foil segment 112 does not participate in winding. In the first empty foil section 112 and the second empty foil section 122, the first diaphragm 130 can separate and insulate the first empty foil section 112 and the second empty foil section 122, when the electric core is punctured by an external sharp conductor, the first diaphragm 130 between the first empty foil section 112 and the second empty foil section 122 is punctured, and the first empty foil section 112 and the second hole foil section are conducted, so that the electric core is rapidly short-circuited; meanwhile, the short-circuit current can be shunted, so that the electric quantity in the battery core is discharged, the battery is prevented from being ignited, and the safety of the battery is improved.

In addition, it should be noted that, in the embodiment of the present invention, the polarities of the first pole piece 110 and the second pole piece 120 are not specifically required and limited; the first pole piece 110 may be a positive pole piece, and the second pole piece 120 may be a negative pole piece, and at this time, the first body may be an aluminum foil, and the second body may be a copper foil; the first electrode piece 110 may be a negative electrode piece, and the second electrode piece 120 may be a positive electrode piece, in which case, the first body may be a copper foil, and the second body may be an aluminum foil. Accordingly, a negative electrode slurry coating is applied on the copper foil, and a positive electrode slurry coating is applied on the aluminum foil.

Further, in embodiments of the present invention, the slurry may comprise lithium iron phosphate, ternary or other lithium battery slurries. For the negative plate, the copper foil meets the process requirements and the negative slurry coating. For the positive plate, the aluminum foil meets the process requirements and forms a coating layer with positive slurry. And the two sides of the negative pole piece in the winding section are coated with negative pole slurry. And the two sides of the positive pole piece in the winding section are coated with positive pole slurry. In the embodiment of the utility model, the pole piece refers to the foil coated with the slurry, including the foil and the slurry, and the foil refers to the foil which is not coated with any slurry.

Optionally, the first body is a copper foil, and the first slurry layer is a negative slurry coating.

Optionally, the second body is an aluminum foil, and the second slurry layer is a positive slurry coating.

In an alternative embodiment, the length of the first empty foil section 112 is the perimeter length of the outermost turn of the second diaphragm 140, and the first empty foil section 112 can completely cover the outermost turn of the second diaphragm 140. The first empty foil section 112 may be covered on the outside of the cylinder, i.e. the first empty foil section 112 does not participate in the winding, but it is covered on the outside of the cylindrical battery cell 100.

In an alternative embodiment, the length of the second empty foil section 122 is the perimeter length of the outermost turn of the second diaphragm 140, and the second empty foil section 122 can completely cover the outermost turn of the second diaphragm 140. The second empty foil section 122 may be covered on the outside of the cylinder, i.e. the second empty foil section 122 does not participate in the winding, but it is covered on the outside of the cylindrical battery cell 100.

In an alternative embodiment, the first separator 130 has a wound separator segment 131 and a wrapped separator segment 132 in a length direction, the wound separator segment 131 being windable in a cylindrical shape with the first wound segment 111, the second wound segment 121, and the second separator 140, the wrapped separator segment 132 being located between the first empty foil segment 112 and the second empty foil segment 122.

It should be understood that for the first separator 130 to be positioned between the first and

second pole pieces

110 and 120, the first separator 130 may be divided into a wound separator segment 131 and a wrapped separator segment 132, where the wound separator segment 131, the first wound segment 111, the wound separator segment 131, and the second wound segment 121 are wound in layers; in the wrapped membrane section 132, the first empty foil section 112, the wrapped membrane section 132, and the second perforated foil section are wrapped in sequence. In the embodiment of the present invention, when the battery cell is punctured by an external sharp conductor, the coating membrane section 132 between the first empty foil section 112 and the second empty foil section 122 can conduct the first empty foil section 112 of the first pole piece 110 and the second hole foil section of the second pole piece 120, so as to rapidly short-circuit the battery cell; meanwhile, the short-circuit current can be shunted, so that the electric quantity in the battery core is discharged, the battery is prevented from being ignited, and the safety of the battery is improved.

In an alternative embodiment, the length of the wrapped membrane segment 132 is greater than the length of the first empty foil segment 112 and greater than the length of the second empty foil segment 122 to better achieve wrapping of the first and second

empty foil segments

112, 122.

Optionally, the length of the wrapped membrane segment 132 is 2-5 mm longer than the first empty foil segment 112 or the second empty foil segment 122, such as the length of the wrapped membrane segment 132 exceeds the first empty foil segment 112 or the second empty foil segment 122 mm.

The present invention provides a secondary battery comprising a cylindrical battery cell 100 as in any of the preceding embodiments.

The utility model provides an automobile comprising the secondary battery according to the foregoing embodiment.

Referring to fig. 1 to fig. 4, a cylindrical battery cell 100, a secondary battery, and an automobile according to an embodiment of the present invention: the first pole piece 110, the first separator 130, the second pole piece 120, and the second separator 140 are wound in a cylindrical shape, thereby forming the cylindrical battery cell 100. During winding, the second diaphragm 140, the second pole piece 120, the first diaphragm 130 and the first pole piece 110 are wound around the winding needle in and out in the sequence from outside to inside. The first separator 130 is disposed between the first pole piece 110 and the second pole piece 120, and plays a role of separation and insulation. The first separator 130 between the first pole piece 110 and the second pole piece 120 can be wound together with a very small distance, so that a high volumetric energy density of the battery can be realized, the high volumetric energy density can bear more energy in a limited space, and the battery endurance can be further improved. In the embodiment of the present invention, in the first empty foil section 112 and the second empty foil section 122, the first membrane 130 may perform a separation and insulation function on the first empty foil section 112 and the second empty foil section 122, when the electric core is punctured by an external sharp conductor, the first membrane 130 between the first empty foil section 112 and the second empty foil section 122 is punctured, and the first empty foil section 112 and the second hole foil section are conducted, so that the electric core is rapidly short-circuited; meanwhile, the short-circuit current can be shunted, so that the electric quantity in the battery core is discharged, the battery is prevented from being ignited, and the safety of the battery is improved.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A cylindrical electrical core, comprising a first pole piece (110), a second pole piece (120), a first separator (130) and a second separator (140);

the first pole piece (110), the first diaphragm (130), the second pole piece (120) and the second diaphragm (140) are sequentially stacked and wound into a column shape from inside to outside, the second diaphragm (140) is located on the outermost layer of the cylindrical battery core (100), the first pole piece (110) comprises a first body and a first slurry layer, and the second pole piece (120) comprises a second body and a second slurry layer;

the first body has a first winding section (111) and a first empty foil section (112) in a length direction, and the first slurry layer is coated on two opposite sides of the first body of the first winding section (111); the second body has a second winding section (121) and a second empty foil section (122) in a length direction, the second slurry layer is coated on opposite sides of the second body of the second winding section (121), the first winding section (111), the second membrane (140), the second winding section (121), and the second membrane (140) are wound in a cylindrical shape, and the first membrane (130) extends from the first winding section (111) and the second winding section (121) to the first empty foil section (112) and the second empty foil section (122).

2. The cylindrical cell of claim 1, wherein the first body is a copper foil and the first slurry layer is a negative slurry coating.

3. The cylindrical cell of claim 1, wherein the second body is an aluminum foil and the second slurry layer is a coating of positive slurry.

4. The cylindrical cell of claim 1, wherein the first empty foil section (112) has a length that is the length of the perimeter of the outermost turn of the second membrane (140), and the first empty foil section (112) is capable of completely covering the outermost turn of the second membrane (140).

5. The cylindrical cell of claim 1, wherein the length of the second empty foil segment (122) is the length of the perimeter of the outermost turn of the second membrane (140), and the second empty foil segment (122) can completely cover the outermost turn of the second membrane (140).

6. The cylindrical cell of any of claims 1 to 5, wherein the first separator (130) has a wound separator section (131) and a wrapped separator section (132) in a length direction, the wound separator section (131) being windable into a cylindrical shape with the first wound section (111), the second wound section (121), and the second separator (140), the wrapped separator section (132) being located between the first empty foil section (112) and the second empty foil section (122).

7. The cylindrical cell of claim 6, wherein the length of the wrapped membrane segment (132) is greater than the length of the first empty foil segment (112) and greater than the length of the second empty foil segment (122).

8. The cylindrical cell of claim 6, wherein the length of the wrapped separator segment (132) is 2-5 millimeters longer than the first empty foil segment (112) or the second empty foil segment (122).

9. A secondary battery, characterized in that it comprises a cylindrical cell (100) according to any of claims 1 to 8.

10. An automobile characterized by comprising the secondary battery according to claim 9.