Pole piece assembly, battery cell and battery

Abstract

The utility model provides a kind of pole piece assembly, electric core and battery, wherein pole piece assembly includes composite pole piece and adapter piece.The composite pole piece includes composite foil current collector, and the composite foil current collector includes substrate layer, first conductive layer located at one side of substrate layer and second conductive layer located at the other side of substrate layer;The composite foil current collector has empty foil area, and the empty foil area is provided with through channel sequentially through first conductive layer, substrate layer and second conductive layer;Adapter piece extends to the other side of empty foil area by passing through through channel from one side of empty foil area, to electrically connect first conductive layer and second conductive layer.The pole piece assembly of the utility model embodiment can effectively conduct between the conductive layer of both sides of composite foil current collector.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, specifically relating to an electrode assembly, a battery cell, and a battery. Background Technology

[0002] In the new energy consumer market, lithium-ion batteries have rapidly occupied the 3C digital consumer market, the new energy vehicle market, and the energy storage application market due to their high energy density. With the development of the industry, the requirements for the electrical energy stored per unit mass of lithium-ion batteries are also getting higher and higher, that is, the requirements for the energy density of batteries are getting higher and higher.

[0003] To improve the energy density of lithium-ion batteries, composite foil current collectors are often used instead of traditional metal foil current collectors. Composite foil current collectors have a lower areal density, which reduces the weight of the current collector and thus increases the energy density of the battery. On the other hand, because polymer materials have high ductility, when a lithium-ion battery is impacted by a foreign object, the polymer material can wrap the fracture surface, thereby preventing the fracture from piercing the separator and causing a short circuit, reducing the risk of thermal runaway and improving the safety performance of lithium-ion batteries. However, due to the low conductivity of polymer materials, effective conductivity cannot be achieved between the conductive layers on both sides of the polymer material.

[0004] Therefore, the composite foil current collector in the related technology has the problem that the conductive layers on both sides cannot conduct electricity effectively. Utility Model Content

[0005] This utility model provides an electrode assembly to solve the problem in related technologies where the conductive layers on both sides of the composite foil current collector cannot conduct electricity effectively.

[0006] The electrode assembly of this utility model embodiment includes: A composite electrode sheet, the composite electrode sheet comprising a composite foil current collector, the composite foil current collector comprising a substrate layer, a first conductive layer located on one side of the substrate layer and a second conductive layer located on the other side of the substrate layer; The composite foil current collector has an empty foil area, and the empty foil area is provided with a through channel that sequentially passes through the first conductive layer, the substrate layer and the second conductive layer; An adapter extends from one side of the empty foil area through the through-channel to the other side of the empty foil area to electrically connect the first conductive layer and the second conductive layer.

[0007] The electrode assembly of this utility model provides a through-channel that penetrates the first conductive layer, the substrate layer, and the second conductive layer in the empty foil area of ​​the composite electrode. At the same time, an adapter is provided that extends from one side of the empty foil area through the through-channel to the other side of the empty foil area, thereby achieving the effect of electrically connecting the first conductive layer and the second conductive layer.

[0008] Therefore, the electrode assembly of this utility model embodiment enables effective conductivity between the conductive layers on both sides of the composite foil current collector.

[0009] In some embodiments, the adapter includes a first adapter section located on one side of the empty foil area and a second adapter section located on the other side of the empty foil area; The first transition section has a transition portion that protrudes from the side edge of the empty foil area.

[0010] In some embodiments, the first transition segment and the empty foil region have a first overlapping region that overlaps in the thickness direction of the empty foil region, and the first transition segment and the first conductive layer are electrically connected through the first overlapping region.

[0011] In some embodiments, the first transition section extends in the width direction of the composite foil current collector, and the first overlapping area has a size range of 2-50 mm in the length direction of the composite foil current collector. The first overlapping area has a size range of 2-100 mm in the width direction of the composite foil current collector; The ratio between the dimension of the first overlapping region in the width direction of the composite foil current collector and the width of the composite foil current collector is 5%-90%.

[0012] In some embodiments, the second transition segment and the empty foil region have a second overlapping region that coincides with the thickness direction of the empty foil region, and the second transition segment and the second conductive layer are electrically connected through the second overlapping region.

[0013] In some embodiments, the second transition section extends in the width direction of the composite foil current collector, and the second overlapping area has a size range of 2-50 mm in the length direction of the composite foil current collector. The second overlapping area has a dimension ranging from 2 to 100 mm in the width direction of the composite foil current collector; The ratio between the dimension of the second overlapping region in the width direction of the composite foil current collector and the width of the composite foil current collector is 5%-90%.

[0014] In some embodiments, the cross-section of the through channel in the thickness direction of the empty foil area is square; The dimension of the through channel in the length direction of the composite foil current collector ranges from 3 to 55 mm; The dimension of the through channel in the width direction of the composite foil current collector ranges from 0.2 to 40 mm.

[0015] In some embodiments, the adapter further includes a third adapter segment located within the through channel, one end of the third adapter segment being connected to the first adapter segment, and the other end of the third adapter segment being connected to the second adapter segment; The third transition section is spaced apart from or abuts against the inner wall of the through channel.

[0016] This utility model also provides a battery cell.

[0017] The battery cell of this utility model embodiment includes the electrode assembly as described in the above embodiment.

[0018] This utility model also provides a battery.

[0019] The battery of this utility model embodiment includes the battery cell described in the above embodiment. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the electrode assembly according to an embodiment of the present invention; Figure 2 This is a cross-sectional view of the electrode assembly according to an embodiment of the present utility model; Figure 3 This is one of the enlarged partial views of the electrode assembly according to an embodiment of the present utility model; Figure 4 This is a second enlarged view of the electrode assembly according to an embodiment of the present invention.

[0022] In the picture: 1. Composite electrode; 101. Composite foil current collector; 1011. Substrate layer; 1012. First conductive layer; 1013. Second conductive layer; 102. Empty foil area; 2. Adapter; 201. First adapter section; 2011. Adapter part; 202. Second adapter section; 203. Third adapter section; 3. First overlapping area; 4. Second overlapping area; 5. Through passage. Detailed Implementation

[0023] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0024] In the description of this utility model, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal encapsulation of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] In order to solve the problem that the conductive layers on both sides of the composite electrode 1 in the related technology cannot conduct electricity effectively.

[0027] This invention provides an electrode assembly.

[0028] like Figure 1 As shown, the electrode assembly of this utility model embodiment includes a composite electrode 1 and an adapter 2.

[0029] The composite electrode 1 includes a composite foil current collector 101, which includes a substrate layer 1011, a first conductive layer 1012 located on one side of the substrate layer 1011, and a second conductive layer 1013 located on the other side of the substrate layer 1011. The composite foil current collector 101 has an empty foil region 102, and the empty foil region 102 is provided with a through channel 5 that sequentially passes through the first conductive layer 1012, the substrate layer 1011 and the second conductive layer 1013; The adapter 2 extends from one side of the empty foil area 102 through the through channel 5 to the other side of the empty foil area 102 to electrically connect the first conductive layer 1012 and the second conductive layer 1013.

[0030] The electrode assembly of this utility model provides a through channel 5 through the empty foil area 102 of the composite electrode 1, which penetrates the first conductive layer 1012, the substrate layer 1011, and the second conductive layer. At the same time, an adapter 2 is provided to extend from one side of the empty foil area 102 through the through channel 5 to the other side of the empty foil area 102, thereby achieving the effect of electrically connecting the first conductive layer 1012 and the second conductive layer 1013.

[0031] Therefore, the electrode assembly of this utility model embodiment enables effective conductivity between the conductive layers on both sides of the composite foil current collector 101.

[0032] In some embodiments, such as Figure 2 As shown, the adapter 2 includes a first adapter section 201 located on one side of the empty foil area 102 and a second adapter section 202 located on the other side of the empty foil area 102; The first transition section 201 has a transition portion that protrudes from the side edge of the empty foil area 102.

[0033] It is understandable that by providing a connecting portion protruding from the side edge of the empty foil area 102 in the first connecting section 201 of the adapter 2, it is possible to facilitate the electrical connection of the adapter 2 with other components. For example, the adapter 2 can be a tab, which extends from one side of the empty foil area 102 through the through channel 5 to the other side of the empty foil area 102. On the one hand, it can electrically connect the first conductive layer 1012 and the second conductive layer 1013 based on the connection of the composite electrode 1. On the other hand, the part protruding from the side edge of the electrode can be electrically connected with other components. When the battery is a soft-pack battery, the tab can be electrically connected to an external electrical device. When the battery is a steel-cased battery, the tab can be electrically connected to the terminal post on the battery casing.

[0034] In some embodiments, such as Figure 3 As shown, the first transition section 201 and the empty foil area 102 have a first overlapping area 3 that overlaps with each other in the thickness direction of the empty foil area 102, and the first transition section 201 and the first conductive layer 1012 are electrically connected through the first overlapping area 3.

[0035] The electrode assembly of this utility model provides a first overlapping area 3 on the empty foil area 102, enabling the first transition segment 201 of the adapter 2 to form an effective electrical connection with the first conductive layer 1012. A welding device can be used to weld the portion of the first transition segment 201 corresponding to the first overlapping area 3 and the portion of the empty foil area 102 corresponding to the first overlapping area 3, thereby preventing the first transition segment 201 from detaching from the first conductive layer 1012 and improving the connection quality between the first transition segment 201 and the first conductive layer 1012.

[0036] In some embodiments, the first transition section 201 extends in the width direction of the composite foil current collector 101, and the first overlapping area 3 has a size range of 2-50 mm in the length direction of the composite foil current collector 101. The first overlapping area 3 has a size range of 2-100 mm in the width direction of the composite foil current collector 101; It is understandable that the size range of the first overlapping region 3 in the length direction of the composite foil current collector 101 and the size range of the first overlapping region 3 in the width direction of the composite foil current collector 101 determine the flow area between the adapter 2 and the composite foil current collector 101. The larger the flow area, the stronger the current carrying capacity of the electrode assembly in this embodiment of the present invention. However, the larger the flow area, the larger the volume of the adapter 2 will inevitably be increased, that is, the volume of the electrode assembly in this embodiment of the present invention will be increased. On the one hand, this will reduce the energy density of the battery after assembly, and on the other hand, it will increase the manufacturing cost.

[0037] Therefore, by setting the size range of the first overlapping region 3 in the length direction of the composite foil current collector 101 and the size range of the first overlapping region 3 in the width direction of the composite foil current collector 101 to the above range, the electrode assembly of this utility model can meet the current carrying requirements of the electrode assembly while avoiding excessive increase in the volume of the electrode assembly of this utility model.

[0038] The ratio between the dimension of the first overlapping region 3 in the width direction of the composite foil current collector 101 and the width of the composite foil current collector 101 is 5%-90%.

[0039] Similarly, the ratio between the dimension of the first overlapping region 3 in the width direction of the composite foil current collector 101 and the width of the composite foil current collector 101 determines the flow area between the adapter 2 and the composite foil current collector 101. The larger the flow area, the stronger the current carrying capacity of the electrode assembly in this embodiment of the present invention. However, the larger the flow area, the larger the volume of the adapter 2 will inevitably be, that is, the larger the volume of the electrode assembly in this embodiment of the present invention. On the one hand, this will reduce the energy density of the battery after assembly, and on the other hand, it will increase the manufacturing cost.

[0040] Therefore, by setting the ratio between the dimension of the first overlapping region 3 in the width direction of the composite foil current collector 101 and the width of the composite foil current collector 101 to the above-mentioned range, the electrode assembly of this utility model can meet the current carrying requirements of the electrode assembly while avoiding excessive increase in the volume of the electrode assembly of this utility model.

[0041] In some embodiments, such as Figure 4As shown, the second transition section 202 and the empty foil region 102 have a second overlapping region 4 that coincides with the thickness direction of the empty foil region 102, and the second transition section 202 and the second conductive layer 1013 are electrically connected through the second overlapping region 4.

[0042] The electrode assembly of this utility model provides a second overlapping area 4 on the empty foil area 102, enabling the second transition segment 202 of the adapter 2 to form an effective electrical connection with the second conductive layer 1013. A welding device can be used to weld the portion of the second transition segment 202 corresponding to the second overlapping area 4 and the portion of the empty foil area 102 corresponding to the second overlapping area 4, preventing the second transition segment 202 from detaching from the second conductive layer 1013 and improving the connection quality between the second transition segment 202 and the second conductive layer 1013.

[0043] In some embodiments, the second transition section 202 extends in the width direction of the composite foil current collector 101, and the second overlapping area 4 has a size range of 2-50 mm in the length direction of the composite foil current collector 101. The second overlapping area 4 has a size range of 2-100 mm in the width direction of the composite foil current collector 101; It is understandable that the size range of the second overlapping region 4 in the length direction of the composite foil current collector 101 and the size range of the second overlapping region 4 in the width direction of the composite foil current collector 101 determine the flow area between the adapter 2 and the composite foil current collector 101. The larger the flow area, the stronger the current carrying capacity of the electrode assembly in this embodiment of the present invention. However, the larger the flow area, the larger the volume of the adapter 2 will inevitably be increased, that is, the volume of the electrode assembly in this embodiment of the present invention will be increased. On the one hand, this will reduce the energy density of the battery after assembly, and on the other hand, it will increase the manufacturing cost.

[0044] Therefore, by setting the size range of the second overlapping region 4 in the length direction of the composite foil current collector 101 and the size range of the second overlapping region 4 in the width direction of the composite foil current collector 101 to the above range, the electrode assembly of this utility model can meet the current carrying requirements of the electrode assembly while avoiding excessive increase in the volume of the electrode assembly of this utility model.

[0045] The ratio between the dimension of the second overlapping region 4 in the width direction of the composite foil current collector 101 and the width of the composite foil current collector 101 is 5%-90%.

[0046] Similarly, the ratio between the dimension of the second overlapping region 4 in the width direction of the composite foil current collector 101 and the width of the composite foil current collector 101 determines the flow area between the adapter 2 and the composite foil current collector 101. The larger the flow area, the stronger the current carrying capacity of the electrode assembly in this embodiment of the present invention. However, the larger the flow area, the larger the volume of the adapter 2 will inevitably be, that is, the larger the volume of the electrode assembly in this embodiment of the present invention. On the one hand, this will reduce the energy density of the battery after assembly, and on the other hand, it will increase the manufacturing cost.

[0047] Therefore, by setting the ratio between the dimension of the second overlapping region 4 in the width direction of the composite foil current collector 101 and the width of the composite foil current collector 101 to the above-mentioned range, the electrode assembly of this utility model can meet the current carrying requirements of the electrode assembly while avoiding excessive increase in the volume of the electrode assembly of this utility model.

[0048] In some embodiments, the cross-section of the through channel 5 in the thickness direction of the empty foil area 102 is square; The dimension of the through channel 5 in the length direction of the composite foil current collector 101 ranges from 3 to 55 mm; The dimension of the through channel 5 in the width direction of the composite foil current collector 101 ranges from 0.2 to 40 mm.

[0049] In some embodiments, such as Figure 2 As shown, the adapter 2 also includes a third adapter section 203 located in the through channel 5. One end of the third adapter section 203 is connected to the first adapter section 201, and the other end of the third adapter section 203 is connected to the second adapter section 202. The third transition section 203 is spaced apart from or abuts against the inner wall of the through passage 5.

[0050] Optionally, the third transition segment 203 is arc-shaped.

[0051] The electrode assembly of this utility model provides a third transition segment 203 on the adapter 2 and sets the third connecting segment to be arc-shaped. On the one hand, this allows the adapter 2 to pass through the through channel 5 more easily, and on the other hand, it makes the transition between the first transition segment 201 and the second connecting segment smoother and less prone to breakage.

[0052] This utility model also provides a battery cell.

[0053] The battery cell of this embodiment includes the electrode assembly described in the above embodiment.

[0054] This utility model also provides a battery.

[0055] The battery of this utility model embodiment includes the battery cell described in the above embodiment.

[0056] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. An electrode assembly, characterized in that, include: The composite electrode (1) includes a composite foil current collector (101), which includes a substrate layer (1011), a first conductive layer (1012) located on one side of the substrate layer (1011), and a second conductive layer (1013) located on the other side of the substrate layer (1011). The composite foil current collector (101) has an empty foil area (102), and the empty foil area (102) is provided with a through channel (5) that sequentially passes through the first conductive layer (1012), the substrate layer (1011) and the second conductive layer (1013). The adapter (2) extends from one side of the empty foil area (102) through the through channel (5) to the other side of the empty foil area (102) to electrically connect the first conductive layer (1012) and the second conductive layer (1013).

2. The electrode assembly according to claim 1, characterized in that, The adapter (2) includes a first adapter section (201) located on one side of the empty foil area (102) and a second adapter section (202) located on the other side of the empty foil area (102). The first transition section (201) has a transition portion (2011) protruding from the side edge of the empty foil area (102).

3. The electrode assembly according to claim 2, characterized in that, The first transition section (201) and the empty foil area (102) have a first overlapping area (3) that overlaps in the thickness direction of the empty foil area (102), and the first transition section (201) and the first conductive layer (1012) are electrically connected through the first overlapping area (3).

4. The electrode assembly according to claim 3, characterized in that, The first transition section (201) extends in the width direction of the composite foil current collector (101), and the first overlapping area (3) has a size range of 2-50 mm in the length direction of the composite foil current collector (101). The first overlapping area (3) has a size range of 2-100 mm in the width direction of the composite foil current collector (101); The first overlapping area (3) has a dimension in the width direction of the composite foil current collector (101) and a width of the empty foil area (102) that is 5%-90%.

5. The electrode assembly according to claim 2, characterized in that, The second transition section (202) and the empty foil area (102) have a second overlapping area (4) that coincides with the thickness direction of the empty foil area (102), and the second transition section (202) and the second conductive layer (1013) are electrically connected through the second overlapping area (4).

6. The electrode assembly according to claim 5, characterized in that, The second transition section (202) extends in the width direction of the composite foil current collector (101), and the second overlapping area (4) has a size range of 2-50 mm in the length direction of the composite foil current collector (101). The second overlapping area (4) has a size range of 2-100 mm in the width direction of the composite foil current collector (101); The second overlapping area (4) has a dimension in the width direction of the composite foil current collector (101) that is 5%-90% of the width of the composite foil current collector (101).

7. The electrode assembly according to claim 2, characterized in that, The cross-section of the through channel (5) in the thickness direction of the empty foil area (102) is square; The through channel (5) has a dimension ranging from 3 to 55 mm in the length direction of the composite foil current collector (101); The through channel (5) has a dimension in the width direction of the composite foil current collector (101) ranging from 0.2 to 40 mm.

8. The electrode assembly according to claim 7, characterized in that, The adapter (2) further includes a third adapter section (203) located in the through channel (5), one end of the third adapter section (203) being connected to the first adapter section (201), and the other end of the third adapter section (203) being connected to the second adapter section (202); The third transition section (203) is spaced apart from or abuts against the inner wall of the through channel (5).

9. A battery cell, characterized in that, Includes the electrode assembly as described in any one of claims 1-8.

10. A battery, characterized in that, Including the battery cell as described in claim 9.

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