Battery cell structure

Abstract

Battery cell structure This battery cell structure includes a first electrode current-collecting layer (21), a first active material layer, a separation layer (23), a second active material layer and a second electrode current-collecting layer (25), the current-collecting layers each having a first surface and a second opposite surface, and a first side and a second opposite side, and for stacking, the first surface of layer (21) is disposed opposite the second surface of layer (25), the surface of layer (21) being smaller than the surface of layer (25) and an insulation layer (41) being disposed on each of the two sides of the junction between the second surface of layer (21) and a first electrically conductive contact terminal (215),in order to significantly reduce the risk of short circuits present during battery cell assembly due to the difference in surface area between layers (21) and (25). Figure to be published: Fig. (4A),

Description

Title of the invention: Battery cell structure Scope of the invention

[0001] The present invention relates to a battery cell structure and, in particular, to a battery cell structure in which an insulating layer is added to prevent the risk of a short circuit in stacked battery cells when the surfaces of two electrode current-collecting layers are not equal. Prior art

[0002] In response to the booming market for new energy vehicles, power batteries have been developed as one of the three core technologies of new energy vehicles. Therefore, the design of the battery structure's protection and the thermal management design of power batteries are considered crucial elements of new energy vehicles. Simultaneously, lightweight structures and increased energy density are inevitable trends for improving the lifespan of new energy vehicle batteries.

[0003] To obtain sufficient power and capacity, it is common practice to stack battery cells. Reference will be made to Figures IA and IB. Each battery cell 10 consists of a first current-collecting electrode layer 11, a first active material layer 12, a separation layer 13, a second active material layer 14, and a second current-collecting electrode layer 15, which are stacked successively. A first electrically conductive contact terminal 111 and a second electrically conductive contact terminal 151 extend respectively from a first current-collecting electrode layer 11 and a second current-collecting electrode layer 15, which are provided at the two opposite ends of the corresponding battery cell 10.As shown in Figures IA and IB, this is a typical stack of battery cells connected in parallel, in which electrode current-collecting layers of the same polarity (the first electrode current-collecting layers 11) are in contact with each other. In practice, the surfaces of two electrode current-collecting layers differ slightly. Therefore, two insulating layers 112, 152 are generally applied to the inner sides of the corresponding first electrically conductive contact terminal 111 or the corresponding second electrically conductive contact terminal 151, namely on the side near the corresponding first active material layer 12 and the corresponding second active material layer 14, in order to prevent, when assembling a first electrically conductive contact terminal 111 and a second terminal. electrically conductive contact 151, they do not respectively come into contact with the first current-collecting layer of adjacent electrode 11 and the second current-collecting layer of adjacent electrode 15, which could lead to a possible short circuit.

[0004] However, in the case of large stacked battery cells or in the case of a large number of battery cells connected in parallel, it often happens that the rear side of a respective first electrically conductive contact terminal 111' is exposed due to crushing, tolerance, and other factors (see Figures 2A and 2B). In this case, if this first offset electrically conductive contact terminal 111' is bent, it can come into contact with the edge of the second electrode collector layer 15, which has a larger surface area, and this can lead to a short circuit.

[0005] The invention aims to efficiently solve the aforementioned problems and to propose a battery cell structure. Objective of the invention

[0006] The main objective of the present invention is to provide a battery cell structure in which an insulation layer is added on the rear side of an electrically conductive contact terminal of an electrode current-collecting layer having a smaller surface area and on the end surface of an electrically conductive contact terminal of an electrode current-collecting layer having a larger surface area, in order to considerably reduce the risk of short circuits existing during the assembly of battery cells due to the difference in surface area between the first and second electrode current-collecting layers.

[0007] The present invention relates to a battery cell structure, comprising a first electrode current-collecting layer, a first active material layer, a separation layer, a second active material layer and a second electrode current-collecting layer, which are stacked successively, the first electrode current-collecting layer having a first electrically conductive contact terminal, the second electrode current-collecting layer having a second electrically conductive contact terminal, characterized in that the first electrode current-collecting layer and the second electrode current-collecting layer each have a first surface and a second surface opposite to it, as well as a first side and a second side opposite to it,The first electrically conductive contact terminal extends outwards from the first side of the first current-collecting electrode layer, the second electrically conductive contact terminal extends outwards from the first side of the second current-collecting electrode layer, and, for stacking, the first surface of the first collector layer. electrode current is disposed opposite the second surface of the second electrode current collector layer, the surface of the first electrode current collector layer being smaller than the surface of the second electrode current collector layer and an insulation layer being disposed on each of the two sides of the junction between the second surface of the first electrode current collector layer and the first electrically conductive contact terminal.

[0008] An insulation layer may be located on each of the two sides of the junction between the first electrically conductive contact terminal and the second surface of the first current-collecting electrode layer and extend towards the upper, respectively lower, edge close to the first side, of the second surface of the first current-collecting electrode layer, to form an L-shaped configuration.

[0009] In accordance with various specific embodiments: • the width of the insulation layer located on the second surface of the first electrode current-collecting layer can be in the range of 3 to 7 mm; and / or • the height of the insulation layer located on the second surface of the first current-collecting electrode layer can be in the range of 0.5 to 1.5 mm; and / or • the width of the insulation layer located on the first electrically conductive contact terminal must be at least 1.5 mm; and / or • the height of the insulation layer located on the first electrically conductive contact terminal can be in the range of 2.5 to 8.5 mm; and / or • an insulation layer can be placed on the second side of the second current-collecting electrode layer.

[0010] The present invention also relates to a battery cell structure, comprising a first electrode current-collecting layer, a first active material layer, a separation layer, a second active material layer and a second electrode current-collecting layer, which are stacked successively, the first electrode current-collecting layer having a first electrically conductive contact terminal, the second electrode current-collecting layer having a second electrically conductive contact terminal, characterized in that the first electrode current-collecting layer and the second electrode current-collecting layer each have a first surface and a second surface opposite to it, as well as a first side and a second side opposite to it,The first electrically conductive contact terminal extends outwards from the first side of the first layer. electrode current collector, the second electrically conductive contact terminal extends outwards from the first side of the second electrode current collector layer and, for stacking, the first surface of the first electrode current collector layer is disposed opposite the second surface of the second electrode current collector layer, the surface of the first electrode current collector layer being smaller than the surface of the second electrode current collector layer and an insulation layer being disposed on the second side of the second electrode current collector layer.

[0011] In order to better understand the objectives, technical content, characteristics and advantageous effects of the present invention, concrete examples of implementation are described in detail below. Brief description of the drawings

[0012]

[0013] Fig. 1A is a schematic exploded perspective view of a conventional battery cell structure in which the battery cells are stacked;

[0014] Fig. 1B is a partial schematic cross-sectional view of a conventional battery cell structure in which the battery cells are stacked;

[0015] The [Fig.2A] is a schematic view of the classic battery cell structure, in which in battery cells a short circuit is caused by a shift;

[0016] Fig. 2B is a schematic view of the classic battery cell structure, in which in battery cells a short circuit is caused by a shift;

[0017] Fig. 3 is a schematic exploded view of the battery cell structure according to the invention;

[0018] Fig. 4A is a schematic view of the battery cell structure according to the invention;

[0019] Fig. 4B is a schematic view of the battery cell structure according to the invention;

[0020] Fig. 5 is a side view of the battery cell structure according to the invention;

[0021] Fig. A is a schematic view of an example embodiment of the insulation layer of the battery cell structure according to the invention;

[0022] Fig. B is a schematic view of an example embodiment of the insulation layer of the battery cell structure according to the invention;

[0023] Fig. 7A is a schematic view of the battery cell structure according to the invention, in which the parallel connected battery cells are stacked;

[0024] Fig. 7B is a schematic view of the battery cell structure according to the invention, in which the parallel connected battery cells are stacked;

[0025] Fig. 8A is a schematic view of the battery cell structure according to the invention, in which the electrically conductive contact terminals are folded;

[0026] Figure 8B is a schematic view of the battery cell structure according to the invention, in which an offset occurs during stacking. Detailed description of embodiment examples

[0027] To better understand the advantages, nature, and features of the present invention, exemplary embodiments are described in detail below with reference to the accompanying drawings. The present invention is described with reference to specific exemplary embodiments and specific drawings, but the invention is not limited to them. These exemplary embodiments are provided solely to make this disclosure more comprehensive and easier to understand.

[0028] The terminology used herein serves only to describe specific embodiments and shall not limit the general idea of ​​the invention. As used herein, the singular forms "a," "an," and "the" shall also include the plural forms, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as that attributed to them by a person of average skill in the trade to which the embodiments belong. It should also be made clear that terms, for example those defined in commonly used dictionaries, shall be interpreted as having the meaning consistent with their meaning in the context of the relevant technique, and not in an idealized or excessively formal sense, unless expressly defined herein.

[0029] Reference will be made to [Fig. 3], which shows a battery cell structure according to the invention. The battery cell structure comprises a first electrode current-collecting layer 21, a first active material layer 22, a separation layer 23, a second active material layer 24, and a second electrode current-collecting layer 25. The first electrode current-collecting layer 21 has a first surface 211 and a corresponding second surface 212, and a corresponding first side 213 and second side 214. The second electrode current-collecting layer 25 also has a first surface 251 and a corresponding second surface 252, and a corresponding first side 253 and second side 254. A first contact terminal electrically conductive 215 extending from the first side 213 of the first current-collecting electrode layer 21 and a second electrically conductive contact terminal 255 extending from the first side 253 of the second current-collecting electrode layer 25, the first current-collecting electrode layer 21, the first active material layer 22, the separation layer 23, the second active material layer 24 and the second current-collecting electrode layer 25 being stacked successively to form a battery cell structure.More specifically, for the stacking, the first surface 211 of the first current-collecting electrode layer 21 is arranged opposite the second surface 252 of the second current-collecting electrode layer 25, the first active material layer 22, the separation layer 23 and the second active material layer 24 being successively clamped together, and the outer peripheries of the first active material layer 22 and the second active material layer 24 being surrounded by frame adhesives 221 and 241 respectively to achieve the purpose of insulation and encapsulation.

[0030] Reference will be made to Figures 3, 4A and 4B. For the first electrically conductive contact terminal 215, an insulating layer 2151 is disposed at the lower end of the junction between the first electrically conductive contact terminal 215 and the first current-collecting electrode layer 21, on the side of the first surface 211 of the first current-collecting electrode layer 21 (i.e., towards the inner side). Similarly, for the second electrically conductive contact terminal 255, an insulating layer 2551 is disposed at the lower end of the junction between the second electrically conductive contact terminal 255 and the second current-collecting electrode layer 25, on the side of the second surface 252 of the second current-collecting electrode layer 25 (i.e., towards the inner side).In this way, it is possible to avoid a short circuit caused by contact between the first electrically conductive contact terminal 215 or the second electrically conductive contact terminal 255 and the current-collecting layer of an electrode of different polarity (the second current-collecting layer of an electrode 25 or the first current-collecting layer of an electrode 21).

[0031] Furthermore, the surface area of ​​the first current-collecting layer of electrode 21 is slightly smaller than the surface area of ​​the second current-collecting layer of electrode 25. Consequently, the side view shown in [Fig. 5] shows that the second current-collecting layer of electrode 25 protrudes slightly from its position. As shown in the Figures, the first current-collecting layer of electrode 21 is, for example, identified as the positive electrode and the second current-collecting layer of electrode 25 as the negative electrode; that is, the surface area of ​​the positive electrode current-collecting layer is slightly smaller than the area of ​​the negative electrode current-collecting layer. However, this is only an illustration and should not be interpreted as a restriction that the area of ​​the positive electrode current-collecting layer must be slightly smaller than the area of ​​the negative electrode current-collecting layer. In practice, the area of ​​the negative electrode current-collecting layer may also be slightly smaller than the area of ​​the positive electrode current-collecting layer.

[0032] Considering the short-circuit problem existing in the prior art, which is caused by misalignment due to factors such as high stacking capacity, tolerance, crushing, etc., after the battery cells are stacked, in the battery cell structure according to the invention, an insulating layer 41 is disposed on each of the two sides of the junction between the second surface 212 of the first current-collecting electrode layer 21 and the first electrically conductive contact terminal 215 (see [Fig. 4A]), or an insulating layer 42 is disposed on the second side 254 of the second current-collecting electrode layer 25 (see [Fig. 4B]), or two insulating layers 41 and 42 are disposed simultaneously (see [Fig. 4A]), so that a short circuit does not occur after contact. This part will be described in detail later.

[0033] Reference will be made to [Fig. 0A]. As the rear side (namely the second surface 212) of the first electrode current-collecting layer 21 is exposed during a short circuit caused by a misalignment, an insulation layer 41 is disposed on each of the two sides of the junction between the second surface 212 of the first electrode current-collecting layer 21 and the first electrically conductive contact terminal 215. An insulation layer 41 is disposed on each of the two sides of the junction between the first electrically conductive contact terminal 215 and the second surface 212 of the first electrode current-collecting layer 21 and extends to the second surface 212 of the first electrode current-collecting layer 21 and is adjacent to the upper edge of the first side 213 to form an L-shaped configuration.In terms of size, the width W1 on the second surface 212 of the first current-collecting electrode layer 21 is in the range of 3 mm to 7 mm, the height L1 on the second surface 212 of the first current-collecting electrode layer 21 is in the range of 0.5 mm to 1.5 mm, the width W2 on the first electrically conductive contact terminal 215 is at least 1.5 mm and the height L2 on the first electrically conductive contact terminal 215 is in the range of 2.5 mm to 8.5 mm.

[0034] Reference will now be made to [Fig. 0B]. As the surface area of ​​the second current-collecting layer of electrode 25 is larger than that of the first current-collecting layer of electrode 21, its end face is higher than the position of the first current-collecting electrode layer 21 and is therefore more easily accessible. Consequently, an insulating layer 42 can also be placed on the second side 254 of the second current-collecting electrode layer 25.

[0035] Reference will be made to [Fig. 7A]. In the case of the effective parallel connection, the second surfaces 212 of the first current-collecting electrode layers 21 are brought into contact with each other during the stacking of two battery cell structures. Reference will now be made to [Fig. 7B]. Once the two battery cell structures have been stacked, the first surfaces 251 of the second current-collecting electrode layers 25 located on the outside are then used for stacking to form a stack of two battery cell structures. In this way, battery cells can be stacked successively in sufficient number to form a battery unit. Reference will now be made to [Fig. 8A]. Once the stacking is complete, the first electrically conductive contact terminals 215 are welded to form a parallel connection throughout the battery unit.A second electrically conductive contact terminal 255 (see [Fig. 7B]) located at the other end also functions in the same way and is therefore not described again here. In this case, as shown in Figures 8A and 8B, the rear side (the side of the second surface 212) of a respective first electrically conductive contact terminal 215 is exposed. The arrangement of the insulation layers 41, 42 nevertheless prevents a short circuit that would normally be caused by the contact of a respective first bent electrically conductive contact terminal 215 with the end face (the second side 254) of the corresponding second current-collecting electrode layer 25.

[0036] In summary, the present invention proposes a battery cell structure. Considering the short-circuit problem caused by misalignment due to factors such as high stacking quantity, tolerance, crushing, etc., the present invention further provides an insulation layer at the position where misalignment could lead to a possible contact short circuit, namely on two sides of the junction between the first electrically conductive contact terminal of the first smaller surface electrode current-collecting layer and the outer side of the first electrode current-collecting layer or on the end face (on the second side) of the second larger surface electrode current-collecting layer.Unlike the conventional insulation layer, which is placed on the lower edge of an electrically conductive contact terminal to prevent an internal short circuit of a single battery cell, the present invention makes it possible to avoid a . short circuit caused by electrically conductive contact terminals bent after the battery cells are stacked, thanks to the added layers of insulation.

[0037] The above description represents only preferred examples of the invention and shall not limit the scope of the invention. All equivalent changes and modifications which, in accordance with the description and drawings of the invention, can be made by a person skilled in the art of this field, fall within the scope of the present invention. List of reference signs

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[0055] 10 Battery cell 11 First current-collecting electrode layer 111 First electrically conductive contact terminal 111' First electrically conductive contact terminal 112 Insulation layer 12 First active material layer 13 Layer ofSeparation 14 Second active material layer 15 Second electrode current-collecting layer 151 Second electrically conductive contact terminal 152 Insulation layer 21 First electrode current-collecting layer 211 First surface 212 Second surface 213 First side 214 Second side 215 First electrically conductive contact terminal 2151 Insulation layer

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[0065] 22 First active material layer 221 Frame adhesive 23 Separation layer 24 Second active material layer 241 Frame adhesive 25 Second electrode current-collecting layer 251 First surface 252 Second surface 253 First side 254 Second side

[0066] 255 Second electrically conductive contact terminal 2551 Insulation layer

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[0072] 41 Insulation layer 42 Insulation layer L1 Height L2 Height W1 Width W2 Width

Claims

Demands

1. Battery cell structure, comprising a first electrode current-collecting layer (21), a first active material layer (22), a separation layer (23), a second active material layer (24) and a second electrode current-collecting layer (25), which are stacked successively, the first electrode current-collecting layer (21) having a first electrically conductive contact terminal (215) and the second electrode current-collecting layer (25) having a second electrically conductive contact terminal (255), characterized in that the first electrode current-collecting layer (21) and the second electrode current-collecting layer (25) each have a first surface (211; 251) and a second surface (212; 252) opposite thereto, as well as a first side (213; 253) and a second side (214; 254) opposite thereto,the first electrically conductive contact terminal (215) extends outwards from the first side (213) of the first electrode current-collecting layer (21), the second electrically conductive contact terminal (255) extends outwards from the first side (253) of the second electrode current-collecting layer (25), and, for stacking, the first surface (211) of the first electrode current-collecting layer (21) is arranged opposite the second surface (252) of the second electrode current-collecting layer (25), the surface of the first electrode current-collecting layer (21) being smaller than the surface of the second electrode current-collecting layer (25), and an insulating layer (41) being disposed on each of the two sides of the junction between the second surface (212) of the first electrode current-collecting layer (21) and the first electrically conductive contact terminal driver (215).,

2. Battery cell structure according to claim 1, characterized in that an insulation layer (41) is located on each of the two sides of the junction between the first electrically conductive contact terminal (215) and the second surface (212) of the first electrode current-collecting layer (21) and extends towards the upper, respectively lower, edge near the first side (213) of the second surface (212) of the first current-collecting layer electrode current (21), to form an L-shaped configuration.

3. Battery cell structure according to claim 2, characterized in that the width (Wl) of the insulation layer (41) located on the second surface (212) of the first current-collecting electrode layer (21) is in the range of 3 to 7 mm.

4. Battery cell structure according to claim 2, characterized in that the height (Ll) of the insulation layer (41) located on the second surface (212) of the first current-collecting electrode layer (21) is in the range of 0.5 to 1.5 mm.

5. Battery cell structure according to claim 2, characterized in that the width (W2) of the insulation layer (41) located on the first electrically conductive contact terminal (215) is at least 1.5 mm.

6. Battery cell structure according to claim 2, characterized in that the height (L2) of the insulation layer (41) located on the first electrically conductive contact terminal (215) is in the range of 2.5 to 8.5 mm.

7. Battery element structure according to any one of claims 1 to 6, characterized in that an insulation layer (42) is disposed on the second side (254) of the second current-collecting electrode layer (25).

8. Battery cell structure, comprising a first electrode current-collecting layer (21), a first active material layer (22), a separation layer (23), a second active material layer (24) and a second electrode current-collecting layer (25), which are stacked successively, the first electrode current-collecting layer (21) having a first electrically conductive contact terminal (215) and the second electrode current-collecting layer (25) having a second electrically conductive contact terminal (255), characterized in that the first electrode current-collecting layer (21) and the second electrode current-collecting layer (25) each have a first surface (211;251) and a second surface (212;252) opposite thereto as well as a first side (213;253) and a second side (214;254) opposite to it, the first electrically conductive contact terminal (215) extends outwards from the first side (213) of the first; electrode current collector layer (21), the second electrically conductive contact terminal (235) extends outwards from the first side (253) of the second electrode current collector layer (25) and, for stacking, the first surface (211) of the first electrode current collector layer (21) is disposed opposite the second surface (252) of the second electrode current collector layer (25), the surface of the first electrode current collector layer (21) being smaller than the surface of the second electrode current collector layer (25) and an insulation layer (42) being disposed on the second side (254) of the second electrode current collector layer (25).

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