Method for manufacturing a battery and corresponding battery

Abstract

A method of manufacturing a battery is disclosed. A first stacked component is formed by applying a positive active material to one of two major surfaces of a first separator sheet and applying a negative active material to the other of the two major surfaces of the first separator sheet. A second stacked component is formed by applying the positive active material to one of two major surfaces of a second separator sheet and applying the negative active material to the other of the two major surfaces of the second separator sheet. The first stacked component and the second stacked component are stacked together with each other with a current collector plate interposed between the first stacked component and the second stacked component.

Description

Technical Field

[0001] This invention belongs to the field of secondary batteries. More specifically, this invention relates to a cell stack for manufacturing lithium-ion batteries by stacking a negative electrode, a positive electrode, a separator, and a current collector. Background Technology

[0002] Secondary batteries are ubiquitous in modern consumer electronics and are increasingly used in current vehicle technology. A secondary battery provides a device for storing energy in a stack of two active electrode materials, forming a negative and a positive electrode, separated by a separator, with an electrolyte used for ion transfer between the active electrode materials. The material stack can be packaged, for example, by winding the material stack to obtain a cylindrical battery or by stacking the materials in a prismatic housing.

[0003] When stacking materials, it is crucial that the negative electrode material has a protrusion relative to the positive electrode material, which is arranged opposite the separator between the negative and positive electrode materials. The negative electrode protrusion has proven to be a significant factor in the aging trajectory of lithium-ion batteries. It functions by reversibly altering cell balance through the transfer of active lithium between the negative electrode protrusion and the active negative electrode. The negative electrode protrusion allows for a more uniform distribution of lithium during charging and discharging, reducing dendrite growth on the negative electrode surface. Therefore, a passivation region, known as the protrusion region, exists on the negative electrode, which is not opposite to the corresponding region on the positive electrode. Consequently, the negative electrode protrusion reduces the risk of short circuits and thermal runaway, thus improving battery performance and safety.

[0004] In existing battery manufacturing methods, a negative electrode material is attached to the opposite surface of a first current collector to form a negative electrode, and a positive electrode material is attached to the opposite surface of a second current collector to form a positive electrode. After forming the positive and negative electrodes, these stacked layers are then laminated onto opposite sides of a separator. Summary of the Invention

[0005] [Technical Issues]

[0006] However, when electrodes are laminated onto the separator, this known method of battery manufacturing can lead to a reduction in battery life due to unintentional misalignment of the negative electrode relative to the positive electrode. This misalignment can eliminate the inherently important negative electrode protrusion, or even result in a positive electrode protrusion with the aforementioned implications.

[0007] In view of the prior art, the object of the present invention is to improve the battery manufacturing method and the corresponding battery, thereby reducing the risk of short circuit and thermal runaway, and improving battery performance and safety.

[0008] [Technical Solution]

[0009] According to a first aspect, a battery manufacturing method is provided, comprising the steps of: forming a first stacked component by applying a positive electrode active material to one of the two main surfaces of a first separator and applying a negative electrode active material to the other of the two main surfaces of the first separator. The method further comprises: forming a second stacked component by applying a positive electrode active material to one of the two main surfaces of a second separator and applying a negative electrode active material to the other of the two main surfaces of the second separator. The method then provides for stacking the first stacked component and the second stacked component together, wherein a current collector is inserted between the first stacked component and the second stacked component.

[0010] This method can overcome the following problems faced in the prior art, in which the manufacturing of the defined negative electrode protrusion is prone to error due to the manufacturing method of first applying the active material to the current collector and then only applying it to the separator, which means that the performance and service life of the battery manufactured in this way cannot be reliably guaranteed.

[0011] Therefore, it is important for the method of the present invention to first manufacture the first and second stacked components, which involves applying active material to both sides of the separator sheet, and then laminating these stacked components only to both sides of the current collector. The negative electrode active material can be a negative electrode material. The positive electrode active material can be a positive electrode material. Physical contact between the positive electrode active material and the separator can be provided. Physical contact between the negative electrode active material and the separator can be provided. Physical contact between these stacked components and the current collector can be provided.

[0012] It can be provided that, in a view perpendicular to the main surface of the first and / or second diaphragm sheets, the lateral ends of the negative electrode active material protrude laterally beyond the lateral ends of the positive electrode active material. The lateral ends of the active material layer may be defined by the outer edge of the active material layer, which extends particularly perpendicular to the main surface of the diaphragm.

[0013] It is conceivable that, in a view perpendicular to the main surface of the first or second separator sheet, the width of the positive electrode active material applied to the first separator sheet corresponds to the width of the positive electrode active material applied to the second separator sheet. Similarly, the width of the negative electrode active material applied to the first separator sheet may correspond to the width of the negative electrode active material applied to the second separator sheet. The width of the active material layer can be measured in a direction parallel to the main surface of the separator.

[0014] The first stacked component and / or the second stacked component can be attached to the current collector in such a way that the positive electrode active material applied to the first diaphragm and / or the positive electrode active material applied to the second diaphragm are in physical contact with the current collector.

[0015] The first stacked component and / or the second stacked component can be attached to the current collector in such a way that the negative electrode active material applied to the first diaphragm and / or the negative electrode active material applied to the second diaphragm are in physical contact with the current collector.

[0016] It is conceivable that the first stacked component and the second stacked component are aligned with each other in a view perpendicular to the main surface of the first or second separator sheet. The first stacked component and the second stacked component can be aligned such that the lateral ends of the positive active material on the first separator sheet and the lateral ends of the positive active material on the second separator sheet are aligned with each other. Similarly, in a view perpendicular to the main surface of the first or second separator sheet, the lateral ends of the negative active material on the first separator sheet and the lateral ends of the negative active material on the second separator sheet can be aligned with each other.

[0017] The method may further include attaching another current collector to the first or second stack on the side opposite to the current collector. The current collector may be made of or comprise a first conductive material, and the other current collector may be made of or comprise a second conductive material different from the first conductive material. The current collector may be made of or comprise aluminum. The other current collector may be made of or comprise copper.

[0018] The method may further include the step of forming a third stacked component by applying a positive electrode active material to one of the two main surfaces of the third diaphragm and applying a negative electrode active material to the other of the two main surfaces of the third diaphragm. It may be provided that the third stacked component is stacked on the other current collector in such a way that the active materials of the second stacked component in contact with the other current collector and the active materials of the third stacked component in contact with the other current collector are both positive electrode active materials or both are negative electrode active materials.

[0019] The present invention also relates to a battery obtained by the method of any one of claims 1 to 11, wherein, in a view perpendicular to the main surface of the first separator and / or the second separator, the lateral end of the negative electrode active material protrudes laterally beyond the lateral end of the positive electrode active material, wherein the section of the negative electrode active material protruding beyond the positive electrode active material has the same size at both lateral ends, and wherein the section of the negative electrode active material protruding beyond the positive electrode active material has the same size at each stacked component.

[0020] The manufacturing method of this invention ensures that all stacked components have a constant negative electrode protrusion relative to the positive electrode active material, achieved by applying the active material to both sides of the separator instead of to the current collector as known in the prior art. This means that if the separator is coated, the gap between the active materials coated on opposite sides of the separator will be uniform. If the active material is coated on the current collector instead of the separator, the gap between the active materials on opposite sides of the separator will not be uniform.

[0021] The present invention also relates to a battery comprising a first stacked component including a first separator, wherein a positive electrode active material is applied to one of the two main surfaces of the first separator, and a negative electrode active material is applied to the other of the two main surfaces of the first separator. The battery further comprises a second stacked component including a second separator, wherein a positive electrode active material is applied to one of the two main surfaces of the second separator, and a negative electrode active material is applied to the other of the two main surfaces of the second separator, wherein the first stacked component and the second stacked component are stacked on top of each other, wherein a current collector is inserted between the first stacked component and the second stacked component. The positive electrode active material and / or the negative electrode active material may be attached to the separator, such that the positive electrode active material is in physical contact with the separator.

[0022] Both the first and second stacked components can be attached to the current collector in such a way that the positive electrode active materials applied to the first diaphragm and the positive electrode active materials applied to the second diaphragm are in physical contact with the current collector. Alternatively, the negative electrode active materials applied to the first diaphragm and the negative electrode active materials applied to the second diaphragm can be in physical contact with the current collector.

[0023] The battery may include another current collector attached to a first or second stack on a side opposite to the aforementioned current collector. The additional current collector is attached in such a manner that it is in physical contact with an active material layer opposite to the active material layer attached to the current collector, wherein the active material layers are separated by corresponding separators.

[0024] In a view perpendicular to the main surface of the first diaphragm and / or the second diaphragm, the lateral end of the negative electrode active material may protrude laterally beyond the lateral end of the positive electrode active material.

[0025] The section of the negative electrode active material that protrudes beyond the positive electrode active material can have the same size at both lateral ends.

[0026] The section of the negative electrode active material that protrudes beyond the positive electrode active material can have the same size at both the first and second stacked components. Due to the manufacturing method of the present invention, protrusion areas of equal size can be ensured, such that not only do the two lateral ends of the negative electrode active material in the same stacked component have uniform negative electrode protrusions, but all stacked components also have uniform negative electrode protrusions.

[0027] The method described in the first aspect can be performed to provide the battery described in the first aspect, and the features of the method can be applied to the characteristics of the battery, and vice versa.

[0028] [Beneficial Effects]

[0029] According to the present invention, an improved battery manufacturing method and a corresponding battery are provided, thereby reducing the risk of short circuits and thermal runaway, and improving the performance and safety of the battery. Attached Figure Description

[0030] The features and numerous advantages of the method and battery of the present invention will be best understood through a detailed description of preferred embodiments with reference to the accompanying drawings, in which: Figure 1 The stacking order of a stacked body with a membrane between the positive and negative electrodes, as known in the prior art, is shown; Figure 2 The proper alignment of the stack of positive and negative electrodes and the separator, as known in the prior art, is shown; Figure 3 This illustrates improper misalignment of the stack of positive and negative electrodes and the separator, as known in the prior art. Figure 4 An example of the stacking order of the first electrode, the second electrode, and the diaphragm therebetween of the present invention is shown; Figure 5 An example of proper alignment of the first and second electrodes and the stack of the diaphragm of the present invention is shown; Figure 6 An example of a stack of the first and second electrodes and the diaphragm of the present invention without improper misalignment is shown; and Figure 7 An example of a stack of the first, second, and third electrodes and diaphragms of the present invention without improper misalignment is shown. Detailed Implementation

[0031] Figures 1 to 3The process steps of a manufacturing process known in the prior art for producing an electrode stack are shown. First, a negative electrode A and a positive electrode B are manufactured. To manufacture electrode A, a layer of negative electrode active material 3 is applied to the opposing main surfaces of current collector 40. To prepare electrode B, a layer of positive electrode active material 1 is applied to the opposing main surfaces of current collector 30. As a result, electrode A is formed into a stack in the following order: a first layer of negative electrode active material 3, current collector 40, and a second layer of negative electrode active material 3. Correspondingly, electrode B is formed into a stack in the following order: a first layer of positive electrode active material 1, current collector 30, and a second layer of positive electrode active material 1. Only after electrodes A and B have been formed does the prior art process provide for laminating the electrodes onto the separator 2.1. The electrodes are connected to the separator 2.1 by bonding a layer of negative electrode active material 3 of electrode A and a layer of positive electrode active material 1 of electrode B to the opposing sides of the separator 2.1. In order to create the negative electrode protrusion AO, when laminated onto the separator 2.1, electrodes A and B must be aligned with each other so that a layer of negative electrode active material 3 with a larger width W3 overlaps with a layer of positive electrode active material 1 with a smaller width W1 at the two lateral ends.

[0032] Figure 2 The result of properly aligned electrode stacks is shown. It can be seen that electrodes A and B are connected to the separator 2.1, resulting in negative electrode protrusions AO on both sides of the stack. This means that the two lateral ends of a layer of negative electrode active material 3 attached to the separator 2.1 overlap with the corresponding lateral ends of a layer of positive electrode active material 1 attached to the opposite side of the separator 2.1.

[0033] However, because the lamination process is inherently less precise in aligning the layers or stacks to be connected, there is a risk of misalignment between electrodes A and B by laminating electrodes A and B onto the separator 2.1, such as... Figure 3 As shown, electrode stack A is laminated too far to the right of electrode stack B on separator foil 2.1. Although this creates an excessively large negative electrode protrusion on the right side of negative electrode active material 3 compared to positive electrode active material 1, the stack has an inappropriate protrusion of positive electrode material 1 on its left side (shown by the dashed circle) compared to negative electrode active material 3. This affects the charging and discharging process of the battery and exacerbates dendrite growth on the negative electrode surface. Therefore, this positive electrode protrusion increases the risk of battery short circuit and thermal runaway.

[0034] Figures 4 to 7An example of the process steps for manufacturing the electrode stack of the present invention is shown. Specifically, the present invention provides a method for firstly manufacturing a first stack component 10 and a second stack component 20, and then laminating the first stack component 10 and the second stack component 20 onto opposite sides of a current collector 30. To manufacture the electrode 10, a layer of negative electrode active material 1 is applied to one of the two main surfaces of the first separator 2.1, and a layer of positive electrode active material 3 is applied to the opposite main surface of the first separator 2.1. To manufacture the electrode 20, a layer of negative electrode active material 1 is applied to one of the two main surfaces of the second separator 2.2, and a layer of positive electrode active material 3 is applied to the opposite main surface of the second separator 2.2. As a result, the electrode 10 is formed into a stack in the following order: negative electrode active material layer 1, first separator 2.1, and positive electrode active material layer 3. Correspondingly, the electrode 20 is formed into a stack in the following order: negative electrode active material layer 3, second separator 2.2, and positive electrode active material layer 1. Because the process of applying active materials 1 and 3 to the separators 2.1 and 2.2 is more precise than the lamination step of laminating the stacks 10 and 20 to the current collector 30, the active materials 1 and 3 can be better aligned with each other, minimizing the risk of misalignment due to possible loss of the negative electrode protrusion. By directly laminating the positive and negative electrode active materials 1 and 3 onto both sides of the separators 2.1 and 2.2 in the first process step, a significantly more precise and clearer negative electrode protrusion AO can be generated. After fabricating the electrode stacks 10 and 20, they are attached to the opposite sides of the current collector 30, such that the two positive electrode active material layers 1 or the two negative electrode active material layers 3 of the two electrode stacks 10 and 20 are in physical contact with the current collector 30. Then, another current collector 40 is laminated onto one of the positive or negative electrode material layers 1 or 3 of one of the electrode stacks 10 and 20 on the side opposite to the current collector 30.

[0035] Figure 5 The result of properly aligned electrode stacks is shown. It can be seen that electrodes 10 and 20 are attached to current collector 30 such that electrodes 10 and 20 are aligned with each other relative to current collector 30. This means that since the two positive electrode active material layers 1 have the same width W1 and the two negative electrode active material layers 3 have the same width W3, the lateral ends of the positive electrode active material layer 1 and the lateral ends of the negative electrode active material layer 3 are aligned with each other.

[0036] Figure 6The results of a biased electrode stack using the method of the present invention are shown. It can be seen that electrode 10 has a lateral bias relative to electrode 20, such that the lateral ends of the positive active material layer 1 of the first electrode 10 and the second electrode 20, and the lateral ends of the negative active material layer 3 of the first electrode 10 and the second electrode 20, are not aligned, but are biased against each other. However, since the positive active material layer 1 and the negative active material layer 3 arranged on opposite sides of the separator surface have been properly aligned with each other beforehand, there is no problem of missing negative electrode protrusions. As a result, even after electrodes 10 and 20 have been laminated onto the current collector 30, electrodes 10 and 20 both have the desired negative electrode protrusion AO.

[0037] Figure 7 An electrode stack is shown, with Figure 6 Compared to the electrode stack 20, this electrode stack has another stack 50 on another current collector 40, which is aligned in the same way as the stack 20. The negative electrode active material layer 3 is on the lower side and adjacent to the other current collector 40, the third separator 2.3 is disposed above the negative electrode active material layer 3, and the positive electrode active material layer 1 is disposed above it. It can be seen that the intermediate stack 10 and the upper stack 50 are also offset from each other relative to the other current collector 40, and all negative electrode protrusions of the positive electrode active material layer 1 and the negative electrode active material layer 3 adjacent to the separators 2.1, 2.2, and 2.3 are in the desired configuration, thereby ensuring good battery performance and lifespan.

[0038] The description of preferred embodiments and accompanying drawings is for illustrative purposes only and should not be construed as implying any limitations. The scope of the invention is determined solely by the appended claims.

[0039] List of reference numerals

[0040] 1: Positive electrode active material

[0041] 2.1: First diaphragm

[0042] 2.1: Second diaphragm

[0043] 3: Negative electrode active material

[0044] 10: First stacked component

[0045] 20: Second stacked components

[0046] 30: Collector plate

[0047] 40: Another manifold

[0048] 50: Third stack component

[0049] A: Negative electrode

[0050] AO: Negative electrode protrusion

[0051] B: Positive electrode

[0052] W1: Width of the positive electrode active material

[0053] W3: Width of the negative electrode active material

Claims

1. A battery manufacturing method, comprising: The first stacked component (10) is formed by applying the positive electrode active material (1) to one of the two main surfaces of the first diaphragm sheet (2.1) and applying the negative electrode active material (3) to the other of the two main surfaces of the first diaphragm sheet (2.1); A second stacked component (20) is formed by applying a positive electrode active material (1) to one of the two main surfaces of the second diaphragm sheet (2.2) and applying a negative electrode active material (3) to the other of the two main surfaces of the second diaphragm sheet (2.2); and The first stack component (10) and the second stack component (20) are stacked on top of each other, wherein a collector plate (30) is inserted between the first stack component (10) and the second stack component (20).

2. The battery manufacturing method as described in claim 1, in, In a view perpendicular to the main surface of the first diaphragm (2.1) and / or the second diaphragm (2.2), the lateral end of the negative electrode active material (3) protrudes laterally beyond the lateral end of the positive electrode active material (1).

3. The battery manufacturing method as described in claim 1 or 2, in, In a view perpendicular to the main surface of the first diaphragm (2.1) and / or the second diaphragm (2.2), the width (W1) of the positive active material (1) applied to the first diaphragm (2.1) corresponds to the width (W1) of the positive active material (1) applied to the second diaphragm (2.2), and / or the width (W3) of the negative active material (3) applied to the first diaphragm (2.1) corresponds to the width (W3) of the negative active material (3) applied to the second diaphragm (2.2).

4. The battery manufacturing method according to any one of claims 1 to 3, in, The first stacked component (10) and the second stacked component (20) are attached to the current collector (30) in such a way that the positive electrode active material (1) applied to the first diaphragm (2.1) and the positive electrode active material (1) applied to the second diaphragm (2.2) are in physical contact with the current collector (30).

5. The battery manufacturing method according to any one of claims 1 to 3, in, The first stacking component (10) and the second stacking component (20) are attached to the current collector (30) in such a way that the negative electrode active material (3) applied to the first diaphragm (2.1) and the negative electrode active material (3) applied to the second diaphragm (2.2) are in physical contact with the current collector (30).

6. The battery manufacturing method as described in any of the preceding claims, in, The first stacked component (10) and the second stacked component (20) are aligned with each other in a view perpendicular to the main surface of the first diaphragm (2.1) or the second diaphragm (2.2).

7. The battery manufacturing method as described in claim 6, in, The first stacked component (10) and the second stacked component (20) are aligned with each other in a view perpendicular to the main surface of the first diaphragm (2.1) or the second diaphragm (2.2), such that the lateral ends of the positive active material (1) on the first diaphragm (2.1) and the lateral ends of the positive active material (1) on the second diaphragm (2.2) are aligned with each other, and / or such that the lateral ends of the negative active material (3) on the first diaphragm (2.1) and the lateral ends of the negative active material (3) on the second diaphragm (2.2) are aligned with each other.

8. The battery manufacturing method as described in any of the preceding claims, further comprising: On the side opposite to the current collector (30), another current collector (40) is attached to the first stack (10) or the second stack (20).

9. The battery manufacturing method as described in claim 8, in, The current collector (30) is made of a first conductive material, and the other current collector (40) is made of a second conductive material different from the first conductive material.

10. The battery manufacturing method as described in claim 9, in, The current collector (30) is made of aluminum, and the other current collector (40) is made of copper.

11. The battery manufacturing method according to any one of claims 8 to 10, further comprising: A third stacked component (50) is formed by applying a positive electrode active material (10) to one of the two main surfaces of the third diaphragm sheet (2.3) and applying a negative electrode active material (20) to the other of the two main surfaces of the third diaphragm sheet (2.3); and The third stacked component (50) is stacked on the other current collector (40) in such a way that the active materials (10, 20) of the second stacked component (20) in contact with the other current collector (40) and the active materials (10, 20) of the third stacked component (50) in contact with the other current collector (40) are both positive active materials (10) or both negative active materials (20).

12. A battery obtained by the method of any one of claims 1 to 11, wherein, In a view perpendicular to the main surface of the first diaphragm (2.1) and / or the second diaphragm (2.2), the lateral end of the negative electrode active material (3) protrudes laterally beyond the lateral end of the positive electrode active material (1), wherein the section of the negative electrode active material (3) protruding beyond the positive electrode active material (1) has the same size at both lateral ends, and wherein the section of the negative electrode active material (3) protruding beyond the positive electrode active material (1) has the same size at each stacked component (10, 20, 50).

13. A battery comprising: A first stacked component (10) includes a first diaphragm sheet (2.1), wherein a positive electrode active material (1) is applied to one of the two main surfaces of the first diaphragm sheet (2.1), and a negative electrode active material (3) is applied to the other of the two main surfaces of the first diaphragm sheet (2.1); A second stacked component (20) includes a second diaphragm sheet (2.2), wherein a positive electrode active material (1) is applied to one of the two main surfaces of the second diaphragm sheet (2.2), and a negative electrode active material (3) is applied to the other of the two main surfaces of the second diaphragm sheet (2.2); The first stacking component (10) and the second stacking component (20) are stacked on top of each other, and the current collector (30) is inserted between the first stacking component (10) and the second stacking component (20).

14. The battery as claimed in claim 13, in, Both the first stacking component (10) and the second stacking component (20) are attached to the current collector (30) in the following manner: - The positive electrode active material (1) applied to the first diaphragm (2.1) and the positive electrode active material (1) applied to the second diaphragm (2.2) are in physical contact with the current collector (30); - Alternatively, the negative electrode active material (3) applied to the first diaphragm (2.1) and the negative electrode active material (3) applied to the second diaphragm (2.2) are in physical contact with the current collector (30).

15. The battery of claim 13 or 14, further comprising: Another collector plate (40) is attached to the first stack (10) or the second stack (20) on the side opposite to the collector plate (30).

16. The battery as claimed in any one of claims 13 to 15, in, In a view perpendicular to the main surface of the first diaphragm (2.1) and / or the second diaphragm (2.2), the lateral end of the negative electrode active material (3) protrudes laterally beyond the lateral end of the positive electrode active material (1).

17. The battery as claimed in claim 16, in, The section of the negative electrode active material (3) that protrudes beyond the positive electrode active material (1) has the same size at both lateral ends.

18. The battery as claimed in claim 17, in, The section of the negative electrode active material (3) that protrudes beyond the positive electrode active material (1) has the same size at the first stack (10) and the second stack (20).

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