Laminated battery structure

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a laminated battery structure which comprises a laminated battery cell body, a shell and a cover plate arranged on the shell, a mounting cavity is formed between the shell and the cover plate; the laminated battery cell body is arranged in the mounting cavity; the laminated cell body comprises a first pole piece, a first diaphragm and a second pole piece which are sequentially arranged around a laminated sheet; the first pole piece is connected to the cover plate; and the second pole piece is connected to the shell. According to the utility model, the expansion deformation of the first pole piece or the second pole piece can be effectively inhibited, the structural stability of the battery is improved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and particularly relates to a stacked battery structure. Background Art

[0002] Large cylindrical lithium batteries have advantages such as standardization, consistency, and safety, and have been widely applied to vehicles as power batteries. At the same time, higher requirements are also put forward for large cylindrical lithium batteries. For example, it is required that large cylindrical lithium batteries achieve higher mass energy density, higher production efficiency, lower production cost, and higher safety, etc.

[0003] With the increasing requirements for battery energy density, the silicon doping amount of the anode is getting higher and higher, and in some cases, a pure silicon anode is used; however, the expansion rate of the pure silicon anode is very large. Without external pressure constraint, the expansion will cause a sharp decline in electrical performance. During the cycling process, with the thickening of the separator and other side reactions, the active lithium ions will decrease accordingly, so the capacity of lithium ions will also gradually decrease; therefore, the stability and safety of use will be reduced. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a stacked battery structure aiming at the deficiencies of the prior art, which can solve the technical problems of low stability and safety in the use of the prior art.

[0005] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0006] A stacked battery structure includes a stacked battery cell body, a housing, and a cover plate arranged on the housing; and an installation cavity is provided between the housing and the cover plate; the stacked battery cell body is arranged inside the installation cavity; the stacked battery cell body includes a first pole piece, a first separator, and a second pole piece that are sequentially stacked around; and the first pole piece is connected to the cover plate; the second pole piece is connected to the housing.

[0007] Preferably, the first pole piece, the first separator, and the second pole piece are sequentially stacked around along the thickness direction of the stacked battery cell body.

[0008] Preferably, the bottom of the stacked battery cell body is inclined with respect to the cover plate; and / or the inner bottom of the stacked battery cell body is inclined with respect to the housing.

[0009] Preferably, the stacked battery cell body is perpendicular to the bottom of the cover plate and the inner bottom of the housing respectively.

[0010] Preferably, the stacked battery structure further includes a channel; the channel penetrates through the housing and / or the cover plate along the thickness direction.

[0011] Preferably, a first insulating member is further provided between the housing and the cover plate.

[0012] Preferably, a second insulating member is provided between the first pole piece and the housing and / or between the second pole piece and the housing.

[0013] Preferably, the stacked battery structure further includes a third pole piece; a lithium metal sheet is provided inside the third pole piece; the lithium metal sheet is disposed between the stacked battery cell body and the housing and / or between the stacked battery cell body and the cover plate.

[0014] Preferably, the lithium metal sheet is disposed between the inner side wall of the housing and the outer surface of the stacked battery cell body arranged in a stacked manner around; and / or the lithium metal sheet is disposed between the inner side wall of the housing and the outer surface of the stacked battery cell body arranged in a stacked manner around.

[0015] Preferably, a second separator is provided on at least one surface of the lithium metal sheet; a side surface of the second separator abuts against the inner side wall of the housing, and / or a side surface of the second separator abuts against a side end of the stacked battery cell body.

[0016] The beneficial effect of the present utility model lies in that, by adopting the first pole piece and the second pole piece arranged in a stacked manner around in sequence, the expansion stress received by the first pole piece or the second pole piece itself can be made to squeeze towards the adjacent pole piece, thereby effectively suppressing the expansion deformation of the first pole piece or the second pole piece itself, further effectively improving the structural stability of the stacked battery cell body, and reducing the extrusion deformation of the housing and / or the cover plate, and prolonging its service life; in addition, through the annular structure formed by arranging in a stacked manner around in sequence, heat can be effectively diffused from the middle of the stacked battery cell body, thereby improving the stability in use and prolonging its service life. Description of the Drawings

[0017] The following will refer to the attached Figures 1 to 5 to describe the features, advantages and technical effects of the exemplary embodiments of the present utility model.

[0018] Figure 1 is a vertical cross-sectional view of the stacked battery structure according to an embodiment of the present utility model;

[0019] Figure 2 is a horizontal cross-sectional view of the stacked battery structure according to an embodiment of the present utility model;

[0020] Figure 3 is a partial enlarged view of the stacked battery structure according to an embodiment of the present utility model

[0021] Figure 4A horizontal cross-sectional view of the stacked battery structure according to another embodiment of the present utility model;

[0022] Figure 5 A horizontal cross-sectional view of the stacked battery structure according to yet another embodiment of the present utility model.

[0023] In the figure: 1 - housing; 2 - cover plate; 101 - installation cavity; 3 - stacked battery cell body; 31 - first electrode plate; 32 - first separator; 33 - second electrode plate; 4 - third electrode plate; 41 - lithium metal sheet; 42 - second separator; 5 - first insulating member; 6 - second insulating member; 7 - channel. Detailed implementation manners

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0025] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, "a plurality of" means two or more unless otherwise specifically defined.

[0026] Referring to "embodiments" herein means that specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0027] In the description of the embodiments of this application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can mean: A exists alone, A and B exist simultaneously, and there are multiple situations where A exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0028] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0029] The following will be further described in detail with reference to the attached Figures 1 to 5 This utility model is further described in detail, but it is not a limitation to this utility model.

[0030] As Figure 1 and 2 shown, in an embodiment of the present utility model, the laminated battery structure includes a laminated battery cell body 3, a housing 1, and a cover plate 2 provided on the top of the housing 1; and an installation cavity 101 is provided between the housing 1 and the cover plate 2; the laminated battery cell body 3 is disposed inside the installation cavity 101; the laminated battery cell body 3 includes a first electrode plate 31, a first separator 32, and a second electrode plate 33 that are sequentially wound and laminated; and the first electrode plate 31 is connected to the cover plate 2; the second electrode plate 33 is connected to the housing 1.

[0031] The technical solution of the present utility model can realize the expansion stress received by the first electrode plate or the second electrode plate itself to be extruded toward the adjacent electrode plate by adopting the first electrode plate and the second electrode plate that are sequentially wound and laminated, so as to effectively inhibit the expansion deformation of the first electrode plate or the second electrode plate itself, and further effectively improve the structural stability of the laminated battery cell body and extend its service life; in addition, through the annular structure formed by sequential winding and lamination, heat can be effectively diffused from the middle of the laminated battery cell body, thereby improving the stability of use and extending its service life.

[0032] Among them, the first electrode plate 31 is an anode plate, and the second electrode plate 33 is a cathode plate. Or, the first electrode plate 31 is a cathode plate, and the second electrode plate 33 is an anode plate. Further, as Figure 1 and 2 shown, the first electrode plate 31, the first separator 32, and the second electrode plate 33 are sequentially wound and laminated along the thickness direction (Z-axis direction) of the laminated battery cell body 3. That is to say, the laminated battery cell body 3 is a ring-shaped laminated battery cell structure; thus, heat can be effectively diffused from the middle of the laminated battery cell body, so as to improve the stability of use and extend its service life. Further, as Figure 1As shown, the top of the first pole piece 31 is (welded) connected to the cover plate 2; the bottom of the second pole piece 33 is (welded) connected to the inner bottom of the housing 1. That is to say, the bottom of the first pole piece 31 (cathode piece) is welded to the inner bottom of the housing 1, making the entire metal housing the negative electrode; the top of the second pole piece 33 (anode piece) is welded to the bottom of the cover plate 2, making the entire metal cover plate 2 the positive electrode.

[0033] Specifically, in some embodiments, as Figure 1 shown, the laminated battery cell body 3 is inclined with respect to the bottom of the cover plate 2; and / or the laminated battery cell body 3 is inclined with respect to the inner bottom of the housing 1. Preferably, the laminated battery cell body 3 is perpendicularly arranged with respect to the bottom of the cover plate 2 and the inner bottom of the housing 1 respectively. That is to say, by making the laminated battery cell body 3 perpendicular to the cover plate 2 and the housing 1 respectively, it is possible to avoid, as much as possible, the stress generated when the first pole piece 31 or the second pole piece 32 expands from being applied to the cover plate 2 or the housing 1, and it is possible to make the expansion stress suffered by the first pole piece or the second pole piece itself squeeze towards the adjacent pole piece, thereby effectively suppressing the expansion deformation of the first pole piece or the second pole piece itself, further realizing the self-restraint effect, and effectively improving the structural stability of the laminated battery cell body and prolonging its service life.

[0034] Specifically, in some embodiments, as Figure 1 and 3 shown, the laminated battery structure further includes a channel 7; the channel 7 runs through the housing 1 and / or the cover plate 2 along the thickness direction (Z-axis direction). That is, the cross-section of the laminated battery structure can be circular or any rounded polygon. In some of these embodiments, as Figure 3 shown, the channel 7 runs through the housing 1 and the cover plate 2 along the thickness direction respectively. That is to say, in order to achieve a better heat dissipation effect, a through-channel 7 is provided in the middle of the laminated battery structure, which can improve the delivery of the heat dissipation air flow and effectively reduce the material input of the housing 1 and the cover plate 2, thereby reducing costs. In other embodiments, the channel 7 only runs through the housing 1 or the cover plate 2 along the thickness direction. This structure forms a heat dissipation swirling gas quickly in the hollowed-out area by hollowing out the middle part of the housing 1 or the cover plate 2, thereby improving the heat dissipation speed and efficiency.

[0035] Specifically, in some embodiments, as Figure 1 shown, a first insulating member 5 is further provided between the housing 1 and the cover plate 2. That is to say, when the cover plate 2 is used as the anode and the housing 1 is used as the cathode; or when the cover plate 2 is used as the cathode and the housing 1 is used as the anode; the housing 1 and the cover plate 2 are separated by the first insulating member 5 to avoid phenomena such as short circuits, thereby improving the safety and stability of use. Among them, the first insulating member 5 can be an insulating sheet such as rubber; and the shape of the first insulating member 5 is an annular structure.

[0036] Specifically, in some embodiments, as Figure 1 shown, a second insulating member 6 is provided between the first pole piece 31 and the housing 1 and / or between the second pole piece 33 and the housing 1. Among them, as Figure 1 shown, a second insulating member 6 is provided between the first pole piece 31 and the housing 1, and a second insulating member 6 is provided between the second pole piece 33 and the housing 1. Further, the second insulating member 6 can be an insulating ring such as rubber. By the second insulating member 6, phenomena such as short circuit are avoided, thereby improving the safety and stability of use.

[0037] Specifically, in some embodiments, as Figure 1 shown, the stacked battery structure further includes a third pole piece 4; a lithium metal sheet 41 is provided inside the third pole piece 4; the lithium metal sheet 41 is disposed between the stacked battery cell body 3 and the housing 1 and / or between the stacked battery cell body 3 and the cover plate 2. That is to say, the lithium metal sheet 41 performs an online lithium ion replenishment process on the stacked battery cell body 3, thereby effectively improving the Coulomb efficiency of the stacked battery structure and extending its service life.

[0038] Specifically, in some of these embodiments, as Figure 2 shown, the number of lithium metal sheets 41 is one, and it is disposed between the inner side wall of the housing 1 and the inner surface of the stacked battery cell body 3 arranged in a stacked manner. That is to say, the inner wall provided with the lithium metal sheet 41 can perform an online lithium ion replenishment process from the inner end, thereby effectively improving the Coulomb efficiency of the stacked battery structure and extending its service life.

[0039] Specifically, in some other embodiments, as Figure 4 shown, the number of lithium metal sheets 41 is one, and it is disposed between the inner side wall of the housing 1 and the outer surface of the stacked battery cell body 3 arranged in a stacked manner. That is to say, the outer wall provided with the lithium metal sheet 41 can perform an online lithium ion replenishment process from the outer end, thereby effectively improving the Coulomb efficiency of the stacked battery structure and extending its service life.

[0040] Specifically, in some other embodiments, as Figure 5 shown, the number of lithium metal sheets 41 is two, and they are respectively disposed between the inner side wall of the housing 1 and the outer surface of the stacked battery cell body 3 arranged in a stacked manner, and between the inner side wall of the housing 1 and the outer surface of the stacked battery cell body 3 arranged in a stacked manner. That is to say, the inner and outer walls provided with the lithium metal sheets 41 can perform an online lithium ion replenishment process from the inner and outer ends, thereby effectively improving the Coulomb efficiency of the stacked battery structure and extending its service life. In addition, during battery detection, the charging rate can be increased and the positive overvoltage can be prevented to improve the cycle life.

[0041] That is to say, a lithium metal sheet 41 is used on the outer or inner side of the housing 1; to serve as a third composite electrode during the cycling process, so as to supplement lithium online during the battery cycling process, and the lithium potential of the positive and negative electrodes can be detected separately, and the charging strategy can be adjusted in real time. Therefore, compared with the general battery structure, the distance between the electrode plates of the general battery structure is relatively long from the edge. If online lithium supplementation is used, the lithium ions inside the general battery structure cannot enter the electrode plates evenly. However, the electrode plate of this technical solution has a small width, and the lithium ion transmission path is small during online lithium supplementation, and the lithium ions can easily enter the electrode plate evenly, achieving a better lithium supplementation effect. In addition, in the later stage of cycling of this technical solution, the active lithium decreases, and the third composite electrode can be used as the positive electrode to supplement lithium online to the anode electrode, so that the active lithium returns to the normal level. Therefore, this technical solution can use the third composite electrode to detect the positive and negative electrode potentials in real time during use; at the same time, the charging rate can be adjusted in real time to keep the lithium potential of the negative electrode in a safe position at all times, so as to avoid lithium deposition and achieve the maximum charging rate; and it can prevent the positive electrode from exceeding the tolerable voltage.

[0042] Specifically, in some embodiments, as Figure 2 shown, a second separator 42 is provided on at least one surface of the lithium metal sheet 41; the side surface of the second separator 42 abuts against the inner side wall of the housing 1, and / or the side surface of the second separator 42 abuts against the side end of the stacked battery cell body 3. Among them, as Figure 2 shown, second separators 42 are provided on both the inner and outer side surfaces of the lithium metal sheet 41; the side surface of one second separator 42 abuts against the inner side wall of the housing 1; and the side ends of the first electrode plate 31, the first separator 32, and the second electrode plate 33 respectively abut against the side surface of the other second separator 42.

[0043] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0044] Based on the disclosure and teachings of the above specification, those skilled in the art to which the present invention pertains can also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the above specific embodiments, and any obvious improvements, substitutions or variations made by those skilled in the art based on the present invention fall within the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

1. A laminated battery structure, characterized in that: It includes a stacked battery cell body, a housing, and a cover plate disposed on the housing; and an installation cavity is provided between the housing and the cover plate; the stacked battery cell body is disposed inside the installation cavity; the stacked battery cell body includes a first pole piece, a first separator, and a second pole piece that are sequentially stacked and wound around; and the first pole piece is connected to the cover plate; the second pole piece is connected to the housing.

2. The laminated battery structure according to claim 1, wherein: The first pole piece, the first separator, and the second pole piece are sequentially stacked and wound around along the thickness direction of the stacked battery cell body.

3. The laminated battery structure according to claim 1 or 2, characterized in that: The stacked battery cell body is inclined with respect to the bottom of the cover plate; and / or the stacked battery cell body is inclined with respect to the inner bottom of the housing.

4. The laminated battery structure according to claim 3, wherein: The stacked battery cell body is perpendicular to the bottom of the cover plate and the inner bottom of the housing respectively.

5. The laminated battery structure according to claim 1, wherein: The stacked battery structure further includes a channel; the channel penetrates through the housing and / or the cover plate along the thickness direction.

6. The laminated battery structure according to claim 1, wherein: A first insulating member is further provided between the housing and the cover plate.

7. The laminated battery structure according to claim 1 or 6, characterized in that: A second insulating member is provided between the first pole piece and the housing and / or between the second pole piece and the housing.

8. The laminated battery structure according to claim 1, wherein: The stacked battery structure further includes a third pole piece; a lithium metal sheet is provided inside the third pole piece; the lithium metal sheet is disposed between the stacked battery cell body and the housing and / or between the stacked battery cell body and the cover plate.

9. The laminated battery structure according to claim 8, wherein: The lithium metal sheet is disposed between the inner side wall of the housing and the outer surface of the stacked battery cell body that is stacked and wound around; and / or the lithium metal sheet is disposed between the inner side wall of the housing and the outer surface of the stacked battery cell body that is stacked and wound around.

10. The laminated battery structure according to claim 8 or 9, characterized in that: A second separator is provided on at least one surface of the lithium metal sheet; the side surface of the second separator abuts against the inner side wall of the housing, and / or the side surface of the second separator abuts against the side end of the stacked battery cell body.

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