A high-precision laminated battery

Abstract

The utility model discloses a kind of high bag-making precision lamination batteries, relate to lamination battery field.In the utility model, by abandoning the reference positioning between diaphragm and first pole piece when diaphragm bag is made, but the normal of positioning top edge of diaphragm bag and the first pole handle extension direction is included angle inclination, by being respectively provided with first diaphragm edge sealing in the two sides of first pole handle, second diaphragm edge sealing is respectively set in the top and bottom of current collector, third diaphragm edge sealing is respectively provided with in the left and right sides of current collector, and the width of first diaphragm edge sealing, second diaphragm edge sealing and third diaphragm edge sealing is configured to be equal, to realize the edge sealing width controllable between diaphragm bag edge and first pole piece, realize bag-making edge sealing constraint in safety requirement range, improve the setting space of pole piece, improve battery energy density and terminal product endurance capability.

Description

Technical Field

[0001] This utility model relates to the field of stacked cells, and more particularly to a stacked cell battery with high bag-making precision. Background Technology

[0002] With the pursuit of ultra-thin and lightweight designs and long battery life in portable electronic products, pouch lithium-ion batteries have become one of the mainstream technologies due to their advantages such as flexible shape, light weight, and high safety. Especially in scenarios requiring a specific shape to fit within a compact internal space, the application of pouch batteries is becoming increasingly widespread.

[0003] Generally, non-square batteries require a complex bag-making process, in which the positive or negative electrode is wrapped in a separator bag. After bagging, the electrode is stacked sequentially with an electrode of the other polarity to form the battery cell. Then, tabs are welded on, and the battery is sealed with electrolyte in a soft outer packaging made of aluminum-plastic composite film to form the battery.

[0004] The current mainstream pouch battery manufacturing process mainly includes: electrode positioning → covering both sides with separators → separator bag sealing. The heat-sealed bag sealing process occupies space from the electrode, increasing the volume of the cell and the battery. However, errors are unavoidable when the upper and lower separators cover the electrode; if the bag sealing edge is too small, the electrode edges will be exposed. Therefore, on the one hand, the bag sealing edge needs to be as small as possible; on the other hand, it is necessary to ensure a sufficient and constant safety distance between the edge of the wrapped electrode and the sealing area. In actual production, the reserved width for the bag sealing edge is much larger than the actual required spacing, which encroaches on the valuable space inside the battery that could be used for active materials.

[0005] In summary, most of the existing soft-pack batteries with electrode sheet packaging have excessively large bag sealing widths, which severely restricts the battery energy density and the end-product's battery life. Utility Model Content

[0006] To address the problems existing in the prior art, the main objective of this utility model is to provide a stacked battery with high bag-making precision. By changing the positioning reference of the separator sealing edge, the bag sealing edge constraint is kept within the safety requirements, thereby increasing the space for electrode placement, improving battery energy density, and enhancing the end-product's battery life.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A high-precision stacked battery includes a cell body, which includes a bag-making electrode sheet. The bag-making electrode sheet includes a first electrode sheet and a separator bag. The first electrode sheet has a rectangular first current collector, the surface of which is coated with an electrode coating. A rectangular first electrode handle is vertically disposed on the top edge of the current collector. The separator bag has a separator covering both sides of the first electrode sheet, wherein the separator bag completely covers both sides of the current collector and covers both sides of a portion of the root of the first electrode handle. The positioning top edge of the separator bag is inclined at an angle to the normal direction of the extension direction of the first electrode handle. The separator bag has a first separator sealing edge on both sides of the first electrode handle, a second separator sealing edge on the top and bottom of the current collector, and a third separator sealing edge on the left and right sides of the current collector. The widths of the first, second, and third separator sealing edges are equal.

[0009] Preferably, the widths of the first diaphragm sealing edge, the second diaphragm sealing edge, and the third diaphragm sealing edge are 1 mm to 2.5 mm.

[0010] Preferably, the first diaphragm sealing edge, the second diaphragm sealing edge, and the third diaphragm sealing edge are formed by cutting off the rectangular diaphragm sequentially along the outline of the first electrode at intervals after heat sealing the first electrode.

[0011] Preferably, the rectangular diaphragm is inclined at an angle to the first rectangular current collector.

[0012] Preferably, the angle between the positioning top edge of the diaphragm bag and the normal of the extension direction of the first pole handle is α, where α satisfies the following range: 0 < α ≤ 5°.

[0013] Preferably, the battery cell further includes a second electrode sheet, the second electrode sheet having a rectangular second current collector, the surface of the current collector being coated with an electrode coating, and a rectangular second electrode handle being vertically disposed on the top edge of the current collector; the bag-making electrode sheet and the second electrode sheet are alternately stacked to form the battery cell.

[0014] Preferably, the first electrode is a positive electrode, the second electrode is a negative electrode, and the outline of the current collector of the first electrode is located within the outline of the current collector of the second electrode; the outline of the current collector of the second electrode is located within the outline of the diaphragm bag, or the outline of the current collector of the second electrode coincides with the outline of the diaphragm bag.

[0015] Preferably, there are two or more of the bag-making electrode and the second electrode, with the number of second electrodes being one more than the number of bag-making electrodes.

[0016] Preferably, the uppermost and lowermost second electrode sheets are formed by coating the second current collector with an electrode coating on one side, the lower side of the uppermost second electrode sheet is provided with an electrode coating, the upper side of the lowermost second electrode sheet is provided with an electrode coating, and the remaining second electrode sheets are formed by coating the second current collector with an electrode coating on both sides; each of the first electrode sheets is formed by coating the first current collector with an electrode coating on both sides.

[0017] Preferably, the package also includes a packaging body and two tabs, one of which is welded to the first electrode handle of all the bag-making electrode sheets, and the other tab is welded to the second electrode sheet of all the second electrode sheets; the packaging body is wrapped around the battery cell and exposes the two tabs.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] (1) In this utility model, by abandoning the reference positioning between the diaphragm and the first electrode during bag making, the positioning top edge of the diaphragm bag is allowed to be inclined at an angle to the normal direction of the extension direction of the first electrode handle. The first diaphragm sealing edge is provided on both sides of the first electrode handle, the second diaphragm sealing edge is provided on the top and bottom of the current collector, and the third diaphragm sealing edge is provided on the left and right sides of the current collector. The widths of the first diaphragm sealing edge, the second diaphragm sealing edge and the third diaphragm sealing edge are configured to be equal, thereby achieving controllable sealing edge width between the edge of the diaphragm bag and the first electrode, realizing that the sealing edge constraint during bag making is within the safety requirement range, improving the setting space of the electrode, and improving the battery energy density and end-product range.

[0020] (2) In this utility model, no allowance is required for each sealing edge of the diaphragm bag, so the size of the diaphragm bag can be larger than that of the second electrode, and the size of the first electrode can also be larger, so that the first electrode and the second electrode are closer together, forming a larger battery capacity.

[0021] The present invention will be further described below with reference to the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the pouch electrode sheet of the stacked battery according to this utility model;

[0023] Figure 2 This is a schematic diagram of the stacked structure of the battery cell of the stacked battery according to the present invention;

[0024] Figure 3 This is a three-dimensional structural diagram of the cell of the stacked battery according to the present invention;

[0025] Figure 4 This is a cross-sectional structural diagram of the stacked battery according to the present invention.

[0026] Reference numerals: 10, battery cell; 12, packaging body; 13, tab; 20, bag-making electrode; 30, first electrode; 31, first current collector; 32, first electrode handle; 40, diaphragm bag; 41, positioning top edge; 42, first diaphragm sealing edge; 43, second diaphragm sealing edge; 44, third diaphragm sealing edge; 50, second electrode; 51, second current collector; 52, second electrode handle. Detailed Implementation

[0027] To better illustrate the purpose, technical solution, and advantages of this utility model, the specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0028] It should be noted that when a component / part is referred to as being "set on" another component / part, it can be directly set on the other component / part or there may be an intervening component / part. When a component / part is referred to as being "connected / linked" to another component / part, it can be directly connected / linked to the other component / part or there may be an intervening component / part. The term "connected / linked" as used herein can include electrical and / or mechanical physical connections / links. The term "including / comprises" as used herein means the presence of a feature, step, or component / part, but does not exclude the presence or addition of one or more other features, steps, or components / parts. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. Furthermore, in the description of this application, the terms "first," "second," etc., are used for descriptive purposes and to distinguish similar objects only; there is no order between them, nor should they be construed as indicating or implying relative importance. Additionally, in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0030] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0031] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0032] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0033] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0034] like Figures 1 to 4 The image shown is a high-precision stacked battery according to an embodiment of the present invention. The stacked battery includes a cell body 10, a packaging body 12, and electrode tabs 13. (Refer to...) Figures 2 to 4 The battery cell 10 includes a pouch electrode 20 and a second electrode 50, with two or more pouch electrodes 20 and second electrode 50 respectively. The pouch electrodes 20 and second electrode 50 are alternately stacked to form the battery cell 10. The first electrode 30 has a rectangular first current collector 31, the surface of which is coated with an electrode coating, and a rectangular first electrode handle 32 is vertically arranged on the top edge of the current collector. The second electrode 50 has a rectangular second current collector 51, the surface of which is coated with an electrode coating, and a rectangular second electrode handle 52 is vertically arranged on the top edge of the current collector. There are two tabs 13. The first electrode handles 32 of all pouch electrodes 20 are welded to one tab 13, and the second electrode 50 of all second electrodes 50 are welded to the other tab 13. The packaging body 12 wraps around the battery cell 10, exposing the two tabs 13.

[0035] To achieve the purpose of this disclosure, in this embodiment, the diaphragm bag 40 has a diaphragm covering both sides of the first electrode 30. The diaphragm bag 40 completely covers both sides of the current collector and also covers both sides of a portion of the root of the first electrode shank 32. The positioning top edge 41 of the diaphragm bag 40 is inclined at an angle to the normal direction of the extending direction of the first electrode shank 32. The diaphragm bag 40 has first diaphragm sealing edges 42 on both sides of the first electrode shank 32, second diaphragm sealing edges 43 on the top and bottom of the current collector, and third diaphragm sealing edges 44 on the left and right sides of the current collector. The widths of the first diaphragm sealing edges 42, second diaphragm sealing edges 43, and third diaphragm sealing edges 44 are equal.

[0036] It is worth noting that by abandoning the reference positioning between the diaphragm and the first electrode 30 during bag making, and instead allowing the positioning top edge 41 of the diaphragm bag 40 to be inclined at an angle to the normal of the extension direction of the first electrode handle 32, and by providing first diaphragm sealing edges 42 on both sides of the first electrode handle 32, providing second diaphragm sealing edges 43 on the top and bottom of the current collector, and providing third diaphragm sealing edges 44 on the left and right sides of the current collector, and configuring the widths of the first diaphragm sealing edges 42, the second diaphragm sealing edges 43, and the third diaphragm sealing edges 44 to be equal, the sealing edge width between the edge of the diaphragm bag 40 and the first electrode 30 can be controlled.

[0037] It is worth noting that no allowance is required for the sealing edges of the separator bag 40, so the size of the separator bag 40 can be larger than that of the second electrode 50, and the size of the first electrode 30 can also be larger, so that the first electrode 30 and the second electrode 50 are closer together, resulting in a larger battery capacity.

[0038] Therefore, it can be seen that the stacked battery according to this disclosure can achieve bag sealing constraints within the safety requirements, increase the space for electrode placement, and improve battery energy density and end-product range.

[0039] To balance safety and energy density, in this embodiment, the widths of the first diaphragm sealing edge 42, the second diaphragm sealing edge 43, and the third diaphragm sealing edge 44 are specifically 1 mm to 2.5 mm. This size range optimizes the material distribution in the hot-melt zone, minimizing the area of ​​inactive regions and avoiding microcracks caused by heat-sealing stress concentration.

[0040] Specifically, in this embodiment, the first diaphragm sealing edge 42, the second diaphragm sealing edge 43, and the third diaphragm sealing edge 44 are formed by sequentially cutting a rectangular diaphragm along the outline of the first electrode 30 at intervals after heat sealing the first electrode 30. The rectangular diaphragm is inclined at an angle to the rectangular first current collector 31. Therefore, when the diaphragm is placed on both sides of the first electrode 30, no positioning reference is needed, and a larger diaphragm is used for complete coverage. The process of forming the first diaphragm sealing edge 42, the second diaphragm sealing edge 43, and the third diaphragm sealing edge 44 can re-match the size of the diaphragm bag 40 with the first electrode 30, ensuring that the sealing area maintains a precise distance from the edge of the electrode.

[0041] To ensure the versatility of the bag-making electrode 20 and save on manufacturing processes, in this embodiment, the angle between the positioning top edge 41 of the diaphragm bag 40 and the normal direction of the extending direction of the first electrode handle 32 is α, where α satisfies the following range: 0 < α ≤ 5°. This slight tilt can accommodate positioning tolerances for bag making of first electrode sheets 30 of different sizes, while also reducing material cutting waste.

[0042] To optimize the effect of sealing the bag-shaped electrode 20 on battery energy density, in this embodiment, the first electrode 30 is the positive electrode, and the second electrode 50 is the negative electrode. The contour of the current collector of the first electrode 30 is located within the contour of the current collector of the second electrode 50; the contour of the current collector of the second electrode 50 is located within the contour of the separator bag 40, or the contour of the current collector of the second electrode 50 coincides with the contour of the separator bag 40. Thus, the triple contour nesting maximizes space utilization, the inward shrinkage of the positive electrode contour avoids edge lithium deposition, the coverage of the negative electrode contour ensures uniform lithium ion deposition, and the inclusive design of the separator contour eliminates volume waste caused by alignment tolerance.

[0043] To improve the volumetric energy density, this embodiment specifically...

[0044] The number of second electrode sheets 50 is one more than the number of bag-making electrode sheets 20. The topmost and bottommost second electrode sheets 50 are formed by coating an electrode coating on one side of the second current collector 51. The bottom side of the topmost second electrode sheet 50 is coated with an electrode coating, and the top side of the bottommost second electrode sheet 50 is coated with an electrode coating. The remaining second electrode sheets 50 are formed by coating an electrode coating on both sides of the second current collector 51. Each first electrode sheet 30 is formed by coating an electrode coating on both sides of the first current collector 31. The asymmetrical stacking design eliminates ineffective space at the ends and improves the utilization rate of the internal space of the packaging body 12.

[0045] The above embodiments mainly describe the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A stacked battery with high bag-making precision, comprising a cell body (10), the cell body (10) comprising a bag-making electrode sheet (20), the bag-making electrode sheet (20) comprising a first electrode sheet (30) and a separator bag (40), the first electrode sheet (30) having a rectangular first current collector (31), the surface of the first current collector (31) being coated with an electrode coating, and a rectangular first electrode handle (32) being vertically disposed on the top edge of the current collector; the separator bag (40) having a separator covering both sides of the first electrode sheet (30), characterized in that, The diaphragm bag (40) completely covers both sides of the current collector and also covers both sides of the root of the first pole handle (32). The positioning top edge (41) of the diaphragm bag (40) is inclined at an angle to the normal of the extension direction of the first pole handle (32). The diaphragm bag (40) is provided with a first diaphragm sealing edge (42) on both sides of the first pole handle (32), a second diaphragm sealing edge (43) on the top and bottom of the current collector, and a third diaphragm sealing edge (44) on the left and right sides of the current collector. The widths of the first diaphragm sealing edge (42), the second diaphragm sealing edge (43), and the third diaphragm sealing edge (44) are equal.

2. The stacked battery with high bag-making precision according to claim 1, characterized in that: The widths of the first diaphragm seal (42), the second diaphragm seal (43), and the third diaphragm seal (44) are 1 mm to 2.5 mm.

3. The stacked battery with high bag-making precision according to claim 2, characterized in that: The first diaphragm sealing edge (42), the second diaphragm sealing edge (43) and the third diaphragm sealing edge (44) are formed by cutting off the rectangular diaphragm along the outline of the first electrode (30) at the intervals after heat sealing the first electrode (30).

4. A stacked battery with high bag-making precision according to claim 3, characterized in that: The rectangular diaphragm is inclined at an angle to the first rectangular current collector (31).

5. A stacked battery with high bag-making precision according to claim 1, characterized in that: The angle between the positioning top edge (41) of the diaphragm bag (40) and the normal of the extension direction of the first pole handle (32) is α, and α satisfies the following range: 0 < α ≤ 5°.

6. A stacked battery with high bag-making precision according to claim 1, characterized in that: The battery cell (10) also includes a second electrode (50), which has a rectangular second current collector (51) coated with an electrode coating. A rectangular second electrode handle (52) is vertically arranged on the top edge of the current collector. The bag-making electrode (20) and the second electrode (50) are stacked alternately to form the battery cell.

7. A stacked battery with high bag-making precision according to claim 6, characterized in that: The first electrode (30) is the positive electrode, and the second electrode (50) is the negative electrode. The outline of the current collector of the first electrode (30) is located within the outline of the current collector of the second electrode (50). The outline of the current collector of the second electrode (50) is located within the outline of the diaphragm bag (40), or the outline of the current collector of the second electrode (50) coincides with the outline of the diaphragm bag (40).

8. A stacked battery with high bag-making precision according to claim 6, characterized in that: The bag-making electrode (20) and the second electrode (50) are provided in more than two forms, and the number of second electrodes (50) is one more than the number of bag-making electrodes (20).

9. A stacked battery with high bag-making precision according to claim 8, characterized in that: The uppermost second electrode (50) and the lowermost second electrode (50) are formed by coating an electrode coating on one side of the second current collector (51). The lower side of the uppermost second electrode (50) is provided with an electrode coating, and the upper side of the lowermost second electrode (50) is provided with an electrode coating. The remaining second electrodes (50) are formed by coating an electrode coating on both sides of the second current collector (51). Each first electrode (30) is formed by coating an electrode coating on both sides of the first current collector (31).

10. A stacked battery with high bag-making precision according to claim 6, characterized in that: It also includes a packaging body (12) and two tabs (13), one of which is welded to the first pole handle (32) of all the bag-making pole pieces (20) and the other of which is welded to the second pole piece (50) of all the second pole pieces (50); the packaging body (12) is wrapped around the battery cell body (10) and exposes the two tabs (13).

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