A laminated battery and a method of manufacturing the same

Abstract

The present application belongs to the technical field of batteries, and particularly relates to a laminated battery, which comprises a first pole piece (11), a first diaphragm (14), a second pole piece (12) and a second diaphragm (13) arranged in sequence, the first diaphragm (14) is provided with a recess (132), the recess (132) and the second diaphragm (13) surround to form a cavity, and the first pole piece (11) or the second pole piece (12) is accommodated in the cavity. The present application limits the position of the second pole piece or the first pole piece through the recess, ensures that the pole piece will not be offset due to collision, and helps to improve the safety performance of the battery. In addition, the present application also discloses a preparation method of the laminated battery.

Description

Technical Field

[0001] This invention belongs to the technical field of batteries, specifically relating to a stacked battery and its preparation method. Background Technology

[0002] Currently, countries around the world are vigorously developing green and efficient rechargeable batteries. Lithium-ion batteries, as a new type of rechargeable battery, possess advantages such as high energy density and power density, high operating voltage, light weight, small size, long cycle life, good safety, and environmental friendliness. They have broad application prospects in portable electrical appliances, power tools, large-scale energy storage, and electric transportation power supplies. Due to their advantages such as high specific energy, high specific power, high voltage platform, low self-discharge, long cycle life, low environmental pollution, and no memory effect, lithium-ion batteries are widely used in power, consumer, and energy storage applications.

[0003] Currently, conventional stacked cells typically use an anode, separator, and cathode stacked sequentially, utilizing the dimensional difference between adjacent layers to form an overhang, thereby achieving a safe design. However, in this case, the cells are easily affected by collisions during use, causing the electrode plates to shift and creating safety hazards. Summary of the Invention

[0004] One of the objectives of this invention is to address the shortcomings of existing technologies by providing a stacked battery that uses recesses to restrict the position of the second or first electrode, ensuring that the electrode does not shift or become misaligned due to collisions, thereby improving the battery's safety performance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A stacked battery includes a first electrode, a first separator, a second electrode, and a second separator stacked sequentially. The first separator has a recessed portion, and the recessed portion and the second separator surround to form a cavity. The first electrode or the second electrode is accommodated in the cavity.

[0007] Preferably, the width of the second diaphragm is greater than the width of the second electrode, the length of the first diaphragm is equal to the length of the second diaphragm, and the width of the second electrode is greater than the width of the first electrode.

[0008] Preferably, the second diaphragm further includes a horizontal portion connected to the recessed portion.

[0009] Preferably, the recessed portion is rectangular, triangular, or arc-shaped, and the size of the recessed portion is larger than the size of the second electrode or the first electrode.

[0010] Preferably, the second electrode is placed in the recess.

[0011] Preferably, the second electrode is located between the second diaphragm and the first diaphragm.

[0012] Preferably, the distance by which the second electrode extends beyond the first electrode in both length and width directions is 0.01-3 mm; and the distance by which the second diaphragm extends beyond the first electrode in both length and width directions is 0.6-3 mm.

[0013] A second objective of this invention is to provide a method for preparing a stacked battery, comprising the following steps:

[0014] S1. A punch is used to punch a hole, forming a second diaphragm with a recessed portion;

[0015] S2. Heat-treat the second diaphragm to keep the shape of the recessed portion fixed;

[0016] S3. Place the second electrode in the recess;

[0017] S4. Place the second diaphragm and the first diaphragm on both sides of the second electrode;

[0018] S5. Place the first electrode plate on the outside of the second diaphragm or the first diaphragm;

[0019] S6. Repeat steps S3 to S5 to complete the fabrication of the stacked battery.

[0020] Preferably, the depth of the recess is 20-200 micrometers.

[0021] Preferably, the heat treatment temperature is greater than the material transition temperature of the diaphragm, or the heat treatment temperature is less than the material melting point temperature of the diaphragm.

[0022] The beneficial effect of the present invention is that the present invention includes a first electrode, a first diaphragm, a second electrode, and a second diaphragm stacked in sequence, the first diaphragm having a recessed portion, the recessed portion and the second diaphragm surrounding each other to form a cavity, and the first electrode or the second electrode being accommodated in the cavity. Because conventional stacked batteries typically use a second electrode, separator, and first electrode stacked sequentially, the cells are prone to electrode misalignment due to collisions during use, posing a safety hazard. Therefore, to address this issue, the first and second separators are placed opposite each other, forming a cavity to accommodate either the second or first electrode. The second or first electrode is confined within this cavity, ensuring it remains fixed within the second separator and preventing contact due to drops or collisions, thus improving battery safety. With the second electrode inside the cavity and the first electrode outside, the first and second electrodes are insulated from each other by the second or first separator, further reducing the probability of contact. This invention uses a recessed portion to restrict the position of the second or first electrode, ensuring it doesn't shift due to collisions and further enhancing battery safety. Attached Figure Description

[0023] The features, advantages, and technical effects of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the structure of a battery cell according to Embodiment 1 of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of the second diaphragm in Embodiment 1 of the present invention.

[0026] Figure 3 This is a schematic diagram of the structure of the second diaphragm in Embodiment 2 of the present invention.

[0027] The reference numerals in the attached figures are explained as follows:

[0028] 1-Battery cell;

[0029] 11-First electrode;

[0030] 12-Second pole sheet;

[0031] 13-Second diaphragm; 131-Horizontal portion; 132-Recessed portion;

[0032] 14 - First diaphragm. Detailed Implementation

[0033] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0034] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be interpreted as indicating or implying relative importance.

[0035] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] The following is in conjunction with the appendix Figures 1-3 The present invention will be described in further detail, but this is not intended to limit the invention.

[0037] Implementation Method 1

[0038] A stacked battery includes a first electrode 11, a first separator 14, a second electrode 12, and a second separator 13 stacked sequentially. The first separator 14 is provided with a recess 132, and the recess 132 and the second separator 13 surround to form a cavity, in which the first electrode 11 or the second electrode 12 is accommodated.

[0039] Since conventional stacked batteries typically use a stacking method of second electrode, separator, and first electrode, the cell 1 is prone to electrode misalignment due to collisions during use, which can pose a safety hazard. Therefore, to address the issue of electrode misalignment in stacked batteries, the first separator 14 and the second separator 13 are placed opposite each other, forming a cavity to accommodate the second electrode 12 or the first electrode 11. The second electrode 12 or the first electrode 11 is confined within this cavity, ensuring that the first electrode 11 or the second electrode 12 is always fixed within the second separator 13, preventing contact between the first electrode 11 and the second electrode 12 due to mechanical factors such as drops or collisions. This helps improve the safety performance of the battery. When the second electrode 12 is located inside the cavity and the first electrode 11 is located outside the cavity, the first electrode 11 and the second electrode 12 are insulated from each other by the second separator 13 or the first separator 14, reducing the probability of contact between the first electrode 11 and the second electrode 12.

[0040] In this embodiment, the first electrode 11 is a cathode and the second electrode 12 is an anode. However, the present invention is not limited thereto. The first electrode 11 may also be an anode and the second electrode 12 may be a cathode.

[0041] Overhang refers to the portion of the diaphragm that extends beyond the second electrode in both length and width, and the portion of the second electrode 12 that extends beyond the first electrode in both length and width.

[0042] In the stacked battery according to the present invention, the width of the second separator 13 is greater than the width of the second electrode 12, the length of the first separator 14 is equal to the length of the second separator 13, and the width of the second electrode 12 is greater than the width of the first electrode 11. Specifically, the dimensional difference between adjacent layers forms an overhang, which helps to improve battery safety. The width of the second separator 13 is greater than the width of the second electrode 12, and the width of the second electrode 12 is greater than the width of the first electrode 11, reducing the probability of contact between the first electrode 11 and the second electrode 12. The length of the first separator 14 is equal to the length of the second separator 13, facilitating the alignment of the first separator 14 with the second separator 13, which helps to improve the stability between the first separator 14 and the second separator 13.

[0043] In the stacked battery according to the present invention, the second separator 13 further includes a horizontal portion 131, which is connected to the recessed portion 132. Increasing the horizontal portion 131 helps to increase the contact area between the first separator 14 and the second separator 13, thereby improving the stability between the first separator 14 and the second separator 13. The second separator 13 has a partially recessed structure with a recessed portion 132, allowing the first electrode 11 or the second electrode 12 to be placed in the recessed portion 132, thus limiting the position of the first electrode 11 or the second electrode 12.

[0044] In the stacked battery according to the present invention, the second electrode 12 or the first electrode 11 is located between the second separator 13 and the first separator 14. Specifically, the second separator 13 and the first separator 14 serve as a spacer to ensure that the second electrode 12 and the first electrode 11 remain insulated, thereby reducing the probability of contact between the second electrode 12 and the first electrode 11, which could lead to a short circuit.

[0045] In the stacked battery according to the present invention, the second electrode 12 extends beyond the first electrode 11 by 0.01-3 mm in both length and width directions; the second separator 13 extends beyond the first electrode 11 by 0.6-3 mm in both length and width directions. Depending on actual production requirements, the distance by which the second electrode 12 extends beyond the first electrode 11 in both length and width directions can be limited, thus forming an overhang, which helps improve battery safety. Furthermore, the distance by which the second separator 13 extends beyond the first electrode 11 in both length and width directions reduces the probability of contact between the second electrode 12 and the first electrode 11, further contributing to improved battery safety.

[0046] In the stacked battery according to the present invention, the recess 132 is rectangular in shape. In this embodiment, the recess 132 may be rectangular, but the present invention is not limited thereto, and the recess 132 may also be other regular or irregular shapes.

[0047] The working principle of this invention is:

[0048] To address the issue of electrode misalignment in stacked batteries, the first separator 14 and the second separator 13 are placed opposite each other, forming a cavity to accommodate the second electrode 12 or the first electrode 11. The second electrode 12 or the first electrode 11 is confined within this cavity, ensuring that the first electrode 11 or the second electrode 12 is always fixed within the second separator 13. This prevents the first electrode 11 and the second electrode 12 from contacting each other due to mechanical factors such as drops or collisions, thus improving battery safety. When the second electrode 12 is located inside the cavity and the first electrode 11 is located outside the cavity, the first electrode 11 and the second electrode 12 are insulated from each other by the second separator 13 or the first separator 14, reducing the probability of contact between the first electrode 11 and the second electrode 12.

[0049] Implementation Method 2

[0050] Unlike Embodiment 1, the recess 132 in this embodiment is triangular in shape, and its size is larger than that of the second electrode 12 or the first electrode 11. The second electrode 12 is placed in the recess 132. Specifically, the shape of the recess 132 can be triangular, but the present invention is not limited to this; the recess 132 can also be other regular or irregular shapes. The larger size of the recess 132 allows the second electrode 12 or the first electrode 11 to be placed entirely within the recess 132, reducing the probability of a large displacement of the second electrode 12 or the first electrode 11 within the recess 132.

[0051] The other structures are the same as in Implementation Method 1, and will not be described again here.

[0052] Implementation Method 3

[0053] Unlike Embodiment 1, in this embodiment, the second electrode 12 or the first electrode 11 is located between the second diaphragm 13 and the first diaphragm 14. The second electrode 12 extends beyond the first electrode 11 by 0.01-3 mm in both length and width directions; the second diaphragm 13 extends beyond the first electrode 11 by 0.6-3 mm in both length and width directions, and the recess 132 is arc-shaped. Specifically, the second electrode 12 or the first electrode 11 is located between the second diaphragm 13 and the first diaphragm 14, which serves to limit the position of the second electrode 12 or the first electrode 11, ensuring that the first electrode 11 or the second electrode 12 is always fixed in the recess 132, preventing contact between the cathode and the second electrode due to mechanical factors such as drops or collisions, thus improving safety performance. Furthermore, the distance by which the second electrode 12 extends beyond the first electrode 11 in both length and width directions, and the distance by which the second separator 13 extends beyond the first electrode 11 in both length and width directions, are limited to prevent excessively large extensions that would increase the production cost of the second electrode 12 or the second separator 13, thus hindering the reduction of battery production costs. Specifically, the shape of the recess 132 can be arc-shaped, but the present invention is not limited to this; the recess 132 can also be other regular or irregular shapes.

[0054] The other structures are the same as in Implementation Method 1, and will not be described again here.

[0055] Comparative implementation methods

[0056] Unlike Embodiment 1, the diaphragm in this embodiment does not have a recessed portion 132, and adopts a method of stacking the second electrode, diaphragm, and first electrode in sequence.

[0057] The other structures are the same as in Implementation Method 1, and will not be described again here.

[0058] The batteries of the three examples were subjected to rolling and drop safety tests. Five batteries were tested for each test. If no smoke, fire or explosion occurred, the test was passed. The structure is shown in Table 1.

[0059] Table 1

[0060] Serial Number Example Method 1 Example Method 2 Comparative implementation methods Roller throughput 5 / 5 5 / 5 1 / 5 Fall pass rate 5 / 5 5 / 5 0 / 5

[0061] Therefore, the pass rates of both Embodiment 1 and Example 2 are higher than those of the comparative embodiment. It can be concluded that by adding the recessed portion 132, the second electrode 12 or the first electrode 11 is confined in the cavity, ensuring that the first electrode 11 or the second electrode 12 is always fixed in the second diaphragm 13 and will not come into contact with the first electrode 11 and the second electrode 12 due to mechanical factors such as falling or collision, which helps to improve the safety performance of the battery.

[0062] Preparation method

[0063] The method for preparing stacked solar cells includes the following steps:

[0064] S1. A punch is used to punch a hole to form a second diaphragm 13 with a recessed portion 132;

[0065] S2. The second diaphragm 13 is heat-treated to keep the shape of the recess 132 fixed.

[0066] S3. Place the second electrode 12 in the recess 132;

[0067] S4. Place the second diaphragm 13 and the first diaphragm 14 on both sides of the second electrode 12;

[0068] S5. Place the first electrode 11 on the outside of the second diaphragm 13 or the first diaphragm 14;

[0069] S6. Repeat steps S3 to S5 to complete the fabrication of the stacked battery.

[0070] It should be noted that: in step S1, a conventional flat separator can be punched to form a recess 132 on the second separator 13; in step S2, heat treatment can maintain the shape of the recess 132 and reduce the probability of the recess 132 deforming during use; in step S6, several stacked cores of the first embodiment are stacked to form a stacked battery.

[0071] Preferably, the depth of the recess 132 is 20-200 micrometers. Limiting the depth of the recess 132 prevents it from being too deep, which would cause the second electrode 12 or the first electrode 11 to move up and down in the recess 132 and make the overall height of the stacked battery too high, which would be detrimental to improving the cavity utilization rate of the battery. At the same time, it prevents the depth of the recess 132 from being too shallow, which would cause the top of the second electrode 12 or the first electrode 11 to exceed the recess 132, which would be detrimental to improving the flatness of the stacked battery.

[0072] Preferably, the heat treatment temperature is higher than the material transition temperature of the diaphragm, or lower than the material melting point temperature of the diaphragm. Limiting the heat treatment temperature prevents the diaphragm from melting due to excessively high temperatures, while preventing the recessed portion 132 from easily deforming due to excessively low temperatures.

[0073] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A stacked battery, characterized by: The first polar sheet (11), the first diaphragm (14), the second polar sheet (12) and the second diaphragm (13) are sequentially stacked, the first diaphragm (14) is provided with a recess (132), the recess (132) and the second diaphragm (13) surround to form a cavity, and a bent inner wall surface is arranged in the recess (132), and the first polar sheet (11) or the second polar sheet (12) is accommodated in the bent inner wall surface in the cavity, the second diaphragm (13) further comprises a horizontal part (131), the horizontal part (131) is connected to the recess (132), the horizontal part (131) is connected to the first diaphragm (14), and an assembly surface between the horizontal part (131) and the first diaphragm (14) is arranged in a staggered manner with the first polar sheet (11) or the second polar sheet (12).

2. A stacked battery as claimed in claim 1, characterized in that: The width of the second diaphragm (13) is greater than the width of the second polar sheet (12), the length of the first diaphragm (14) is equal to the length of the second diaphragm (13), and the width of the second polar sheet (12) is greater than the width of the first polar sheet (11).

3. A stacked battery as claimed in claim 1, wherein: The shape of the recess (132) is rectangular, triangular or circular arc, and the size of the recess (132) is greater than the size of the second polar sheet (12) or the first polar sheet (11).

4. A stacked battery as claimed in claim 1, wherein: The second polar sheet (12) is placed in the recess (132).

5. A stacked battery as claimed in claim 1, wherein: The second polar sheet (12) is located between the second diaphragm (13) and the first diaphragm (14).

6. A stacked battery as claimed in claim 2, wherein: The second polar sheet (12) exceeds the first polar sheet (11) by a distance of 0.01-3mm in the length and width directions, and the second diaphragm (13) exceeds the first polar sheet (11) by a distance of 0.6-3mm in the length and width directions.

7. A method of manufacturing a stacked battery, characterized by, The method comprises the following steps: S1, a punch is used to form a recess (132) in the second diaphragm (13); S2, the second diaphragm (13) is heat treated to keep the shape of the recess (132) fixed; S3, the second polar sheet (12) is placed in the recess (132); S4, the second diaphragm (13) and the first diaphragm (14) are placed on both sides of the second polar sheet (12); S5, the first polar sheet (11) is placed outside the second diaphragm (13) or the first diaphragm (14); S6, steps S3 to S5 are repeated to complete the preparation of the laminated battery.

8. A method of making a stacked battery as claimed in claim 7, wherein: The depth of the recess (132) is 20-200 microns.

9. The method of claim 7, wherein: The temperature of the heat treatment is greater than the material transition temperature of the diaphragm, or the temperature of the heat treatment is less than the material melting point temperature of the diaphragm.

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