Battery Cell Structure

Abstract

To provide a battery cell structure that reduces the risk of potential short circuits. [Solution] The battery cell structure includes a first current collecting layer 21, a first active material layer 22, a separator 23, a second active material layer 24 and a second current collecting layer 25, which are stacked in this order, and the first current collecting layer and the second current collecting layer have a first surface 211 and a second surface 212 facing each other, respectively. The first surface of the first current collecting layer is stacked facing the second surface of the second current collecting layer, and the area of ​​the first current collecting layer is slightly smaller than that of the second current collecting layer. The second surface of the first current collecting layer has an insulating layer 2151 on both edges of the first current collecting layer at the portion where the second surface contacts the first tab 215, which greatly reduces the risk of a potential short circuit caused by the difference in area between the first and second current collecting layers when assembling the battery cell.

Description

[Technical field]

[0001] The present invention relates to a battery cell structure, particularly to a battery cell structure in which an additional insulating layer is provided to prevent the risk of potential short circuits in stacking of battery cells when the areas of the two current collecting layers are not equal. [Background technology]

[0002] With the rapid development of the new energy vehicle market, the traction battery has been regarded as one of the three core technologies in new energy electric vehicles, and the protection design of the traction battery structure and its temperature management plan are regarded as very important parts of new energy electric vehicles. Furthermore, in order to increase the driving range of new energy electric vehicles, the demand for weight reduction and increased energy density is an inevitable trend.

[0003] To achieve sufficient electrical charge and capacitance, the existing common procedure is to stack the battery cells. 1A and 1B, the battery cell 10 is composed of a first current collecting layer 11, a first active material layer 12, a separator 13, a second active material layer 14, and a second current collecting layer 15, which are stacked in this order, and a first tab 111 and a second tab 151 extend from the first current collecting layer 11 and the second current collecting layer 15, respectively, at opposite ends of the battery cell 10. 1A and 1B show a typical parallel connected stack, where current collecting layers of the same polarity (first current collecting layer 11) are stacked in contact with each other. In actual implementation, since the areas of the two current collecting layers are slightly different, insulating layers 112, 152 are generally provided on the inside of the first tab 111 and the second tab 151, i.e., on the side closer to the first active material layer 12 and the second active material layer 14, to prevent the first tab 111 and the second tab 151 from contacting the adjacent first current collecting layer 11 and the second current collecting layer 15, respectively, when they are assembled, thereby preventing a short circuit from occurring.

[0004] However, when stacking battery cells with a large size or a high number of parallel connections, the rear surface of the first tab 111' is easily exposed after stacking due to factors such as pressure and tolerance. As shown in FIGS. 2A and 2B, when the misaligned first tab 111' is bent, it easily comes into contact with the edge of the second current collecting layer 15, which has a relatively large area, causing a short circuit.

[0005] SUMMARY OF THE DISCLOSURE In view of the above-mentioned shortcomings of the prior art, the present invention provides a battery cell structure to effectively solve the above-mentioned problems. Summary of the Invention [Problem to be solved by the invention]

[0006] The main objective of the present invention is to provide the following battery cell structure. In other words, an insulating layer is additionally provided on the back surface of the tab of the current collecting layer, which has a relatively small area, and on the end surface of the current collecting layer, which has a relatively large area, to provide a battery cell structure that significantly reduces the risk of potential short circuits due to the different areas of the first and second current collecting layers when assembling the battery cell. [Means for solving the problem]

[0007] The present invention discloses a battery cell structure, which includes a first current collecting layer, a first active material layer, a separator, a second active material layer and a second current collecting layer stacked in order, the first current collecting layer having a first tab and the second current collecting layer having a second tab. The first and second current collecting layers have opposing first and second surfaces and opposing first and second sides, respectively, with a first tab extending outwardly from the first side of the first current collecting layer and a second tab extending outwardly from the first side of the second current collecting layer. The first surface of the first current collecting layer is laminated opposite to the second surface of the second current collecting layer, and the area of ​​the first current collecting layer is slightly smaller than the area of ​​the second current collecting layer. The first current collecting layer has an insulating layer on both edge portions of the second surface of the first current collecting layer that contacts the first tab. In addition, the insulating layer can extend to a top edge adjacent to the first side of the second surface of the first current collecting layer and be arranged in an L-shape.

[0008] In addition, the present invention discloses a battery cell structure, which includes a first current collecting layer, a first active material layer, a separator, a second active material layer and a second current collecting layer stacked in sequence, wherein the first current collecting layer has a first tab and the second current collecting layer has a second tab. The first and second current collecting layers have opposing first and second surfaces and opposing first and second sides, respectively, with a first tab extending outwardly from the first side of the first current collecting layer and a second tab extending outwardly from the first side of the second current collecting layer. The first surface of the first current collecting layer is laminated opposite to the second surface of the second current collecting layer, and the area of ​​the first current collecting layer is slightly smaller than that of the second current collecting layer. The second current collecting layer has an insulating layer on a second side thereof.

[0009] The following specific examples are described in detail, so that the objectives, technical contents, features and effects achieved by the present invention can be more easily understood. [Brief description of the drawings]

[0010] [Figure 1A] FIG. 1 is a schematic diagram of stacking in a known battery cell structure. [Figure 1B] FIG. 1 is a schematic diagram of stacking in a known battery cell structure. [Figure 2A] 1 is a schematic diagram of a known stacked battery cell structure where a short circuit occurs due to misalignment; FIG. [Figure 2B] 1 is a schematic diagram of a known stacked battery cell structure where a short circuit occurs due to misalignment; FIG. [Diagram 3] 1 is an exploded schematic diagram of a battery cell structure according to the present invention; [Figure 4A] 1 is a schematic diagram of a battery cell structure according to the present invention; [Figure 4B] 1 is a schematic diagram of a battery cell structure according to the present invention; [Diagram 5] 1 is a side view of a battery cell structure according to the present invention; [Figure 6A] 3A-3C are schematic diagrams illustrating different embodiments of insulating layers in the structure of a battery cell according to the present invention; [Figure 6B] 3A-3C are schematic diagrams illustrating different embodiments of insulating layers in the structure of a battery cell according to the present invention; [Figure 7A] FIG. 2 is a schematic diagram of a stack of parallel connections in a battery cell structure according to the present invention; [Figure 7B] FIG. 2 is a schematic diagram of a stack of parallel connections in a battery cell structure according to the present invention; [Figure 8A] 2 is a schematic diagram of a battery cell structure according to the present invention with a tab folded; FIG. [Figure 8B] 2 is a schematic diagram of a battery cell structure according to the present invention in which stacking is offset; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In order to make the advantages, spirit and features of the present invention more easily and clearly understandable, the following detailed description of the embodiments will be given with reference to the drawings. These examples are merely representative examples of the present invention, and the embodiments and claims of the present invention are not limited to the forms of these examples. The purpose of providing these examples is to make the disclosure of the present invention more thorough and easily understandable.

[0012] The terms used in the various embodiments disclosed in the present invention are used only for the purpose of describing particular embodiments and are not intended to be limiting of the various embodiments disclosed in the present invention. Unless expressly indicated otherwise, the use of the singular includes the plural. Unless otherwise limited, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments disclosed herein belong. The above terms (e.g., terms defined in a commonly used dictionary) are to be construed as having the same meaning as in the context in the same technical field, and are not to be construed as having an idealized or overly formal meaning, unless expressly limited in various embodiments disclosed in the present invention.

[0013] Please refer to Figure 3. The structure of the battery cell disclosed in the present invention includes a first current collecting layer 21, a first active material layer 22, a separator 23, a second active material layer 24 and a second current collecting layer 25. The first current collecting layer 21 has corresponding first and second surfaces 211 and 212, and corresponding first and second sides 213 and 214, and the second current collecting layer 25 has corresponding first and second surfaces 251 and 252, and corresponding first and second sides 253 and 254. A first tab 215 extends from a first side surface 213 of the first current collecting layer 21 , and a second tab 255 extends from a first side surface 253 of the second current collecting layer 25 . The first current collecting layer 21, the first active material layer 22, the separator 23, the second active material layer 24 and the second current collecting layer 25 are laminated in this order to form a battery cell structure. Specifically, the first surface 211 of the first current collecting layer 21 is laminated opposite the second surface 252 of the second current collecting layer 25, and the first active material layer 22, the separator 23, and the second active material layer 24 are sandwiched therebetween in that order. A sealant 221, 241 is wrapped around the first active material layer 22 and the second active material layer 24, thereby achieving the purpose of insulation and sealing.

[0014] 3, 4A, and 4B. First tab 215 has insulating layer 2151 at the bottom of the portion where first tab 215 contacts first current collecting layer 21 on the first surface 211 side (i.e., the inner side) of first current collecting layer 21. Similarly, the second tab 255 has an insulating layer 2551 at the bottom on the second surface 252 side (i.e., the inside) of the second collecting layer 25, where the second tab 255 contacts the second collecting layer 25, thereby preventing the assembled first tab 215 and second tab 255 from coming into contact with collecting layers of different polarity (the second collecting layer 25 and the first collecting layer 21) and causing a short circuit.

[0015] In addition, since the area of ​​first current collecting layer 21 is slightly smaller than the area of ​​second current collecting layer 25, a side view of first current collecting layer 21 shows that second current collecting layer 25 protrudes slightly, as shown in FIG. For example, the first current collecting layer 21 shown in the figure is designated as the positive electrode, and the second current collecting layer 25 is designated as the negative electrode, that is, the area of ​​the positive current collecting layer is slightly smaller than the area of ​​the negative current collecting layer. However, this is merely an outline, and the area of ​​the positive electrode current collecting layer is not limited to being slightly smaller than the area of ​​the negative electrode current collecting layer. In practical design, the area of ​​the negative current collecting layer may be slightly smaller than that of the positive current collecting layer.

[0016] Considering the problem that the above-mentioned known battery cells may be misaligned and short-circuited after stacking due to factors such as high stacking number, tolerance, and pressure, the battery cell structure of the present invention has an insulating layer 41 (as shown in FIG. 6A ) on both edges of the part where the second surface 212 of the first current collecting layer 21 contacts the first tab 215, or has an insulating layer 42 (as shown in FIG. 6B ) on the second side 254 of the second current collecting layer 25, or has two insulating layers 41, 42 at the same time (as shown in FIG. 4A ), so as to prevent short-circuiting even if they come into contact (this will be described in detail later).

[0017] First, refer to Figure 6A. It is considered that when misalignment occurs and a short circuit occurs, the back side of the first current collecting layer 21 (i.e., the second surface 212) is exposed. Therefore, an insulating layer 41 is provided on both edge portions of the portion where the second surface 212 of the first current collecting layer 21 contacts the first tab 215 . The insulating layer 41 is located on both edge portions of the portion where the first tab 215 contacts the second surface 212 of the first current collecting layer 21, and further extends to the top edge adjacent to the first side 213 of the second surface 212 of the first current collecting layer 21, so that two L-shapes are arranged. Regarding their sizes, the width W1 located at the second surface 212 of the first current collecting layer 21 is 3 to 7 mm, the height L1 located at the second surface 212 of the first current collecting layer 21 is 0.5 to 1.5 mm, the width W2 located at the first tab 215 is at least 1.5 mm, and the height L2 located at the first tab 215 is 2.5 to 8.5 mm.

[0018] 6B, the area of ​​the second current collecting layer 25 is larger than that of the first current collecting layer 21, and therefore the end face of the second current collecting layer 25 is located higher than the position of the first current collecting layer 21, allowing for easy contact. Therefore, the second side surface of the second current collecting layer 25 254 It is also possible to provide an insulating layer 42 on the substrate 41 .

[0019] See Figure 7A. When practically applied to parallel connection, the battery cell structures are stacked such that the second surfaces 212 of the first current collecting layers 21 are in contact with each other. After the two battery cell structures are stacked, as shown in FIG. 7B, the first surface 251 of the second current collecting layer 25 located on the outside is further utilized to contact and stack the two battery cell structures to form a stack of the two battery cell structures. In this way, a required number of batteries are stacked in order to form a battery unit. See Figure 8A. After stacking is complete, the first tabs 215 are welded to complete the parallel connection of the entire battery unit. A second tab 255 on the other end (shown in FIG. 7B) is identical and will not be repeated. At this time, as shown in FIGS. 8A and 8B , even if the rear surface (second surface 212 side) of the first tab 215 is exposed due to misalignment, the insulating layers 41 and 42 are provided so that the end surface ( 2nd side 254 ) can prevent the short circuit phenomenon caused by contact with the

[0020] To summarise the above, the present invention presents a structure for a battery cell. Considering the problem of short circuit caused by misalignment due to factors such as high number of layers, tolerance, and pressure, the positions where misalignment may cause contact and short circuit, that is, the peripheral parts on both sides of the part where the first tab of the first current collecting layer, which has a relatively small area, contacts the outside of the first current collecting layer, or the end face of the second current collecting layer, which has a relatively large area ( Second side ) an additional insulating layer is provided. Unlike the known method of providing an insulating layer at the bottom inner edge of a tab to prevent internal short circuiting of a single battery cell, this newly added insulating layer is used to prevent the phenomenon of short circuiting that may occur when the tab is bent after the battery cells are stacked.

[0021] The above description is merely a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, any equivalent changes or modifications made based on the features and spirit described in the claims of the present invention should be included within the scope of the claims of the present invention. [Explanation of symbols]

[0022] 10 Battery Cells 11 First current collecting layer 111 First Tab 111' First Tab 112 Insulating layer 12 First active material layer 13 Separator 14 Second active material layer 15 Second current collecting layer 151 Second Tab 152 Insulating layer 21 First current collecting layer 211 1st surface 212 2nd surface 213 First aspect 214 Second aspect 215 First Tab 2151 Insulation layer 22 First active material layer 221 Sealant 23 Separator 24 Second active material layer 241 Sealant 25 Second current collecting layer 251 1st surface 252 2nd surface 253 First aspect 254 Second aspect 255 2nd tab 2551 Insulation layer 41 Insulating layer 42 Insulating layer L1 Height L2 Height W1 width W2 Width

Claims

1. A battery cell structure including a first current collecting layer, a first active material layer, a separator, a second active material layer, and a second current collecting layer, which are stacked in order, the first current collecting layer having a first tab, and the second current collecting layer having a second tab, a first tab extending outward from the first side of the first current collecting layer and a second tab extending outward from the first side of the second current collecting layer; the first surface of the first current collecting layer being stacked against the second surface of the second current collecting layer; an area of ​​the first current collecting layer being smaller than an area of ​​the second current collecting layer; and an insulating layer being provided on both edge portions of a portion of the first current collecting layer where the second surface of the first current collecting layer contacts the first tab.

2. 2. The battery cell structure of claim 1, wherein the insulating layer is located on both edge portions of the portion where the first tab contacts the second surface of the first current collecting layer, and further extends to a top edge adjacent to the first side surface of the second surface of the first current collecting layer, and is arranged in an L shape.

3. 3. The battery cell structure as claimed in claim 2, wherein the width of the insulating layer located on the second surface of the first current collecting layer is 3 to 7 millimeters.

4. 3. The battery cell structure as claimed in claim 2, wherein the height of the insulating layer on the second surface of the first current collecting layer is 0.5 to 1.5 mm.

5. 3. The battery cell structure as claimed in claim 2, wherein the width of the insulating layer located at the first tab is at least 1.5 mm.

6. 3. The battery cell structure as claimed in claim 2, wherein the height of the insulating layer at the first tab is 2.5 to 8.5 mm.

7. The structure of the battery cell according to claim 1 , further comprising an insulating layer on the second side of the second current collecting layer.

8. A battery cell structure including a first current collecting layer, a first active material layer, a separator, a second active material layer, and a second current collecting layer, which are stacked in order, the first current collecting layer having a first tab, and the second current collecting layer having a second tab, a first tab extending outward from the first side of the first current collecting layer and a second tab extending outward from the first side of the second current collecting layer, the first surface of the first current collecting layer being stacked against the second surface of the second current collecting layer, an area of ​​the first current collecting layer being smaller than an area of ​​the second current collecting layer, and an insulating layer being provided on the second side of the second current collecting layer.

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