Pole piece and battery cell

Abstract

The utility model relates to the technical field of new energy, particularly provides a pole piece and a battery cell, and aims to solve the problem that the conventional pole piece is easy to misplace. Therefore, the pole piece comprises a body and a connecting layer arranged on the body, and the connecting layer comprises a bonding layer connected with the body and a hot melting layer connected with the bonding layer. According to the utility model, the bonding layer is bonded and fixed with the pole piece, and the hot melting layer is connected with the diaphragm in a hot melting manner, so that the pole piece and the diaphragm are stably connected, the dislocation of the pole piece is prevented, and the structural stability and safety are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, and specifically provides a pole piece and a battery core. Background Art

[0002] As people's environmental awareness increases, new energy sources have also developed rapidly, especially lithium batteries, which have been widely used in the automotive and consumer electronics industries.

[0003] Lithium batteries typically include a housing and a cell located within the housing. The cell consists of a stacked positive electrode, a separator, and a negative electrode. The separator is primarily used to separate the positive and negative electrodes, thereby achieving insulation between the two. However, during assembly or use of lithium batteries, the positive electrode, separator, and negative electrode often shift relative to each other, causing the positive and negative electrodes to misalign and short-circuit. Alternatively, thermal contraction of the separator can cause the positive and negative electrodes to short-circuit, potentially leading to safety incidents such as lithium battery fires. This poses a significant safety risk.

[0004] Therefore, this field needs a new technical solution to solve the above problems. Utility Model Content

[0005] The utility model aims to solve the above technical problem, that is, to solve the problem that the existing pole pieces are easily misplaced.

[0006] In a first aspect, the present invention provides a pole piece, which includes a body and a connecting layer provided on the body, wherein the connecting layer includes an adhesive layer connected to the body and a hot melt layer connected to the adhesive layer.

[0007] In the preferred technical solution of the above-mentioned pole piece, the body includes a current collector, and the adhesive layer is connected to the current collector.

[0008] In the preferred technical solution of the above-mentioned pole piece, the body further includes an active material layer, and the adhesive layer is located on one side of the active material layer.

[0009] In the preferred technical solution of the above-mentioned electrode, the body includes a current collector and an active material layer connected to the current collector, and the adhesive layer is connected to the active material layer.

[0010] In the preferred technical solution of the above-mentioned pole piece, the thickness of the adhesive layer is t1, wherein 0.1 micron≤t1≤50 microns.

[0011] In the preferred technical solution of the above-mentioned electrode, the thickness of the hot melt layer is t2, wherein 0.1 micron≤t2≤50 microns.

[0012] In the preferred technical solution of the above-mentioned pole piece, the width of the adhesive layer is w1, wherein 0.1 mm ≤ w1 ≤ 20 mm.

[0013] In the preferred technical solution of the above-mentioned electrode, the width of the hot melt layer is w2, wherein 0.1 mm ≤ w2 ≤ 20 mm.

[0014] In the preferred technical solution of the above-mentioned pole piece, two connecting layers are provided and are respectively located on both sides of the body.

[0015] In a second aspect, the present invention further provides a battery core comprising a diaphragm and a pole piece as described in any one of the above items, wherein the hot melt layer is connected to the diaphragm.

[0016] When adopting the above technical solution, the electrode of the utility model is provided with a connecting layer, which is bonded and fixed to the electrode through the adhesive layer on one side, and is hot-melt connected to the diaphragm through the hot-melt layer on the other side, thereby achieving a stable connection between the electrode and the diaphragm, preventing dislocation of the electrode, and ensuring structural stability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0018] Figure 1 This is a top view of the first embodiment of the pole piece of the utility model;

[0019] Figure 2 yes Figure 1 The cross-sectional view of the pole piece of the present invention along line AA is shown;

[0020] Figure 3 This is a structural diagram of a second embodiment of the pole piece of the utility model;

[0021] Figure 4 This is a schematic structural diagram of a third embodiment of a pole piece of the present utility model;

[0022] Figure 5 It is a structural schematic diagram of the fourth embodiment of the pole piece of the utility model.

[0023] List of reference numerals:

[0024] 100-pole piece; 1-current collector; 2-active material layer; 3-connecting layer; 31-adhesive layer; 32-hot melt layer. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0026] It should be noted that in the description of this utility model, terms such as "inside," "outside," "upper," "lower," "top," "bottom," "left," "right," "front," and "back" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or component described must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] Furthermore, it should be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "connected," and "installed" should be understood in a broad sense, for example, to refer to fixed connections, detachable connections, or integral connections. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0028] The first embodiment of the present invention is described below. Figure 1 and Figure 2 , Figure 1 This is a top view of the first embodiment of the pole piece of the utility model. Figure 2 yes Figure 1 The cross-sectional view of the pole piece of the present invention along line AA is shown.

[0029] like Figure 1 and Figure 2 As shown, the pole piece 100 of the present invention includes a body and a connecting layer 3 arranged on the body. The connecting layer 3 is used to connect the body and the diaphragm (not shown) to achieve a stable connection between the pole piece 100 and the diaphragm, prevent the two from being misaligned, and ensure the stability and safety of the structure.

[0030] Specifically, the shape of the connecting layer 3 can be set as needed. In this embodiment, Figure 1 and Figure 2 As shown, the connection layer 3 is in a rectangular parallelepiped shape. In other embodiments, the connection layer 3 may also be in an arc shape.

[0031] Specifically, the connection layer 3 includes an adhesive layer 31 connected to the body and a hot melt layer 32 connected to the adhesive layer 31 .

[0032] By stacking the adhesive layer 31 and the hot melt layer 32, the adhesive layer 31 and the body can be bonded and fixed so that the connecting layer 3 can be fixed on the body. At the same time, the hot melt layer 32 and the diaphragm can be fixed by hot melting, so that the diaphragm can be flattened when placed on the body before hot pressing to prevent the diaphragm from wrinkling, and to achieve a stable connection between the electrode 100 and the diaphragm, preventing the two from being misaligned and causing a short circuit, thereby ensuring safety.

[0033] The adhesive layer 31 may be a glue layer coated on the surface of the hot melt layer 32 , or may be other adhesive materials, etc., so that it can be bonded to the main body.

[0034] The hot melt layer 32 can be hot melt adhesive or other insulating materials. It only needs to be able to achieve hot melt connection with the diaphragm during hot pressing, which will not be described in detail here.

[0035] The arrangement of the above structure allows, when assembling the electrode 100 and the diaphragm, on the one hand, the connecting layer 3 can be first bonded and fixed to the body of the electrode 100 through the adhesive layer 31. The process is simple and the operation is convenient. The hot melt layer 32 is not sticky before being hot-melted with the diaphragm, that is, in a non-hot-melted state, thereby preventing adhesion to surrounding foreign matter or dust, and the diaphragm can be flattened when placed on the connecting layer 3 to prevent the diaphragm from wrinkling. On the other hand, the hot-melt connection between the hot melt layer 32 and the diaphragm can be achieved by hot pressing, which simplifies the process difficulty and improves production efficiency and yield.

[0036] Further, such as Figure 2 As shown, the thickness of the adhesive layer 31 is t1, where 0.1 micron ≤ t1 ≤ 50 microns. For example, t1 is 0.1 micron, 0.5 micron, 1 micron, 1.5 microns, 2 microns, 5 microns, 10 microns, 15 microns, 20 microns, 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns, etc. The specific value of t1 can be set as needed and will not be repeated here.

[0037] By limiting the range of the thickness t1 of the bonding layer 31 as described above, it is possible to prevent t1 from being too large, which may lead to increased costs and reduced space utilization, and to prevent t1 from being too small, which may affect the stability of the bonding between the electrode 100 and the diaphragm.

[0038] Further, such as Figure 2 As shown, the thickness of the hot melt layer 32 is t2, where 0.1 micron ≤ t2 ≤ 50 microns. For example, t2 is 0.1 micron, 0.5 micron, 1 micron, 1.5 microns, 2 microns, 5 microns, 10 microns, 15 microns, 20 microns, 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns, etc. The specific value of t2 can be set as needed and will not be repeated here.

[0039] By limiting the range of the thickness t2 of the hot melt layer 32 as described above, it is possible to prevent t2 from being too large, which may lead to increased costs and reduced space utilization, and to prevent t2 from being too small, which may affect the stability of the bonding between the electrode 100 and the diaphragm.

[0040] Further, such as Figure 2As shown, the width of the adhesive layer 31 is w1, where 0.1 mm ≤ w1 ≤ 20 mm. For example, w1 is 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, etc. The specific value of w1 can be set as needed and will not be repeated here.

[0041] By limiting the range of the width w1 of the bonding layer 31 as described above, on the one hand, it can prevent w1 from being too large, which will lead to increased costs and reduced space utilization due to the bonding layer 31 occupying too large a volume. On the other hand, it can prevent w1 from being too small, which will affect the stability of the bonding between the electrode 100 and the diaphragm.

[0042] Further, such as Figure 2 As shown, the width of the hot melt layer 32 is w2, where 0.1 mm ≤ w2 ≤ 20 mm. For example, w2 is 0.1 micron, 0.5 micron, 1 micron, 1.5 micron, 2 micron, 5 micron, 10 micron, 15 micron, 20 micron, etc. The specific value of w2 can be set as needed and will not be repeated here.

[0043] By limiting the range of the width w2 of the hot melt layer 32 as described above, on the one hand, it can prevent w2 from being too large, which will lead to increased costs and reduced space utilization due to the hot melt layer 32 occupying too large a volume. On the other hand, it can prevent w2 from being too small, which will affect the stability of the bonding between the electrode 100 and the diaphragm.

[0044] like Figure 1 and Figure 2 As shown, the body includes a current collector 1 and an active material layer 2 disposed on the current collector 1 .

[0045] Specifically, the current collector 1 can be aluminum foil or copper foil, etc. The material selection of the current collector 1 can be set as needed and will not be repeated here.

[0046] Specifically, the active material layer 2 is coated on the surface of the current collector 1. The active material layer 2 can be a positive electrode active material layer or a negative electrode active material layer, etc. It can be selected and set as needed and will not be described in detail here.

[0047] Furthermore, the connection layer 3 is provided on the surface of the active material layer 2 facing away from the current collector 1 , thereby facilitating hot-melt fixing of the hot-melt layer 32 and the separator, thereby ensuring the stability and safety of the structure.

[0048] Furthermore, two connecting layers 3 are provided and are located on both sides of the active material layer 2 in the length direction or width direction, so that a stable connection between the active material layer 2 and the diaphragm can be achieved through the connecting layers 3 on both sides, preventing the diaphragm from being separated from one end of the electrode 100 in the length or width direction and affecting the stability of the overall structure and even affecting safety.

[0049] like Figure 3 As shown, it is the second embodiment of the present invention. In this embodiment, its structure is roughly the same as that of the first embodiment, with the only difference being that: two active material layers 2 are provided and are respectively located on the two surfaces of the current collector 1 in the thickness direction; further, four connecting layers 3 are provided and are respectively located on both sides of the active material layer 2 in the thickness direction.

[0050] The above structure, on the one hand, realizes a stable connection between the electrode 100 and the diaphragm on both sides in the thickness direction, preventing the misalignment of the electrode 100 and the diaphragm and thus affecting the safety of the battery; on the other hand, the energy density and power of the battery are improved by the arrangement of the active material layer 2 on both sides of the current collector 1.

[0051] like Figure 4 As shown, it is the third embodiment of the present invention. In this embodiment, its structure is roughly the same as that of the first embodiment, with the only difference being that the connecting layer 3 is arranged on the current collector 1 and is located on one side of the length or width direction of the active material layer 2.

[0052] Specifically, the adhesive layer 31 is bonded and fixed to the current collector 1 . Preferably, the side surface of the adhesive layer 31 is bonded and fixed to the side surface of the active material layer 2 .

[0053] Furthermore, the hot melt layer 32 is located on the side of the adhesive layer 31 away from the current collector 1 and on the side of the active material layer 2. The side of the hot melt layer 32 is attached to the side of the active material layer 2. The hot melt layer 32 and the active material layer 2 can be bonded or hot-melt connected.

[0054] Furthermore, the thickness of the connection layer 3 is t3, and the thickness of the active material layer 2 is t4, wherein t3≤t4.

[0055] By limiting the above dimensions, on the one hand, the material used in the connecting layer 3 can be reduced, thereby reducing costs; on the other hand, it can ensure that the hot melt layer 32 of the connecting layer 3 and the diaphragm can be firmly bonded, ensuring that the overall structure is stable and safe.

[0056] Preferably, 0.9*t4≤t3≤t4.

[0057] The above-mentioned size limits prevent the thickness of the connecting layer 3 from being too thin, which could affect adhesion and fixation with the diaphragm and, in turn, affect the stability and safety of the overall structure. Furthermore, they prevent the thickness of the connecting layer 3 from being too thick, which could lead to increased material consumption and, in turn, increased costs. Therefore, selecting the above-mentioned range balances cost with structural stability and safety, thereby achieving the optimal and most balanced effect.

[0058] Furthermore, two connecting layers 3 are provided and are located on both sides of the width or length direction of the active material layer 2, so that the electrode 100 can be firmly connected to the diaphragm on both sides of the width or length direction, preventing any end of the electrode 100 in the length or width direction from being separated from the diaphragm.

[0059] like Figure 5 As shown, it is the fourth embodiment of the present utility model. In this embodiment, its structure is roughly the same as that of the third embodiment, with the only difference being that: two active material layers 2 are provided and are respectively located on both sides of the thickness direction of the current collector 1; and, four connecting layers 3 are provided and are respectively located on both sides of the thickness direction of the current collector 1.

[0060] Specifically, two of the four connecting layers 3 are located on one side of the current collector 1 in the thickness direction, and the remaining two connecting layers 3 are located on the other side of the current collector 1 in the thickness direction, thereby achieving a stable connection between the electrode 100 and the diaphragms on both sides of the thickness direction.

[0061] The present invention further provides a battery core, comprising a diaphragm and the pole piece 100 described in any one of the above items, wherein the hot melt layer 32 is connected to the diaphragm.

[0062] The battery cell provided by the present invention can achieve a stable connection between the electrode 100 and the diaphragm, and the connecting layer 3 adopts a stacking design of an adhesive layer 31 and a hot melt layer 32, so that the connecting layer 3 can be first bonded to the electrode 100 through the adhesive layer 31, and then the diaphragm can be placed on the electrode 100. Since the hot melt layer 32 is in a non-hot melt state at this time, the diaphragm can be conveniently flattened to prevent the diaphragm from wrinkling. After the diaphragm is flattened, it can be directly hot-pressed to achieve a stable connection between the electrode 100 and the diaphragm, prevent the diaphragm from wrinkling, and thus improve the battery cell yield.

[0063] Those skilled in the art will appreciate that although some embodiments described herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are intended to be within the scope of this application and to form different embodiments. For example, in the claims of this application, any of the claimed embodiments may be used in any combination.

[0064] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A pole piece, characterized in that: The pole piece includes a body and a connection layer provided on the body, wherein the connection layer includes an adhesive layer connected to the body and a hot melt layer connected to the adhesive layer; The body includes a current collector and an active material layer disposed on the current collector, and the connecting layer is disposed on a surface of the active material layer facing away from the current collector.

2. The pole piece according to claim 1, characterized in that: The adhesive layer is connected to the active material layer.

3. The pole piece according to claim 1, characterized in that: The thickness of the adhesive layer is t1, wherein 0.1 micrometer ≤ t1 ≤ 50 micrometers.

4. The pole piece according to claim 1, characterized in that: The thickness of the hot melt layer is t2, wherein 0.1 micrometers ≤ t2 ≤ 50 micrometers.

5. The pole piece according to claim 1, characterized in that: The width of the adhesive layer is w1, wherein 0.1 mm≤w1≤20 mm.

6. The pole piece according to claim 1, characterized in that: The width of the hot melt layer is w2, wherein 0.1 mm≤w2≤20 mm.

7. The pole piece according to claim 1, characterized in that: There are two connecting layers and they are respectively located on two sides of the main body.

8. A battery cell, characterized in that: The invention comprises a diaphragm and the pole piece according to any one of claims 1 to 7, wherein the hot melt layer is connected to the diaphragm.

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