Battery cell partition plate structure and battery

Abstract

The utility model provides a battery cell separator structure and a battery, the battery cell separator structure comprises a plurality of elastic layers and a plurality of lithium supplement layers, and the elastic layers and the lithium supplement layers are stacked; the elastic layers are arranged on the two outermost sides of the battery cell partition plate structure in the overlapping direction of the elastic layers and the lithium supplementing layers. The lithium ion battery solves the problem that the cycle life of the battery core is not long in the prior art.

Description

Technical Field

[0001] The utility model relates to the field of batteries, and in particular to a battery core partition structure and a battery. Background Art

[0002] In order to meet the growing energy density demand in the secondary battery market, silicon-containing batteries have begun to be used, and batteries with a silicon content of less than 10% have been mass-produced. However, square batteries with high silicon additions still have many technical bottlenecks. If a winding structure is adopted, lithium deposition or black spots are prone to occur at the corners of the core when a high amount of silicon is added. If a stacked structure is adopted, in order to prevent the square from being over-thick and deformed in the later stages of the cycle, a large expansion space will be reserved when the bare cell is put into the shell. Due to the large expansion space, although the square shell is compressed during the decomposition, the internal bare cell is not fully compressed, resulting in wrinkles in the electrode after the decomposition, causing unembedded lithium spots and lithium deposition, which results in the energy density of the cell not meeting expectations and the cell cycle life being poor. Utility Model Content

[0003] The main purpose of the utility model is to provide a battery cell separator structure and a battery to solve the problem of poor battery cell cycle life in the prior art.

[0004] In order to achieve the above-mentioned purpose, according to one aspect of the utility model, a battery cell separator structure is provided, including an elastic layer and a lithium replenishing layer, wherein there are multiple elastic layers, and the elastic layers and the lithium replenishing layers are stacked; along the stacking direction of the elastic layers and the lithium replenishing layers, the two outermost sides of the battery cell separator structure are both elastic layers.

[0005] Furthermore, there are multiple lithium replenishing layers, and at least two lithium replenishing layers are arranged in contact with each other.

[0006] Furthermore, there are multiple lithium replenishing layers, and at least one elastic layer is arranged between at least two adjacent lithium replenishing layers.

[0007] Furthermore, the elastic layer is a porous liquid-absorbing structure.

[0008] Furthermore, the thickness of all elastic layers and lithium replenishing layers along the stacking direction is 1 mm to 1 cm.

[0009] According to another aspect of the utility model, a battery is provided, comprising a battery cell; a shell, in which the battery cell is arranged; the above-mentioned battery cell partition structure, in which the battery cell partition structure is arranged between two battery cells; and / or the battery cell partition structure is arranged between the battery cell and the shell.

[0010] Furthermore, a cell separator structure is provided on at least one side of each cell.

[0011] Furthermore, a cell separator structure is provided on two opposite sides of each cell.

[0012] Furthermore, the cell separator structure covers the entire side of the cell.

[0013] Furthermore, the battery cell separator structure is arranged on one side of at least one large surface of the battery cell.

[0014] By applying the technical solution of the utility model, a battery cell separator structure having an elastic layer and a lithium replenishing layer is provided, wherein the elastic layer can be used to buffer the expansion of the battery cell, and the lithium replenishing layer is used to release lithium ions into the battery cell, thereby improving the cycle life of the battery cell. Specifically, the battery cell separator structure can have one or more lithium replenishing layers and two or more elastic layers, and the two surfaces perpendicular to the stacking direction of the elastic layer and the lithium replenishing layer are elastic layers. On the one hand, the elastic layer has high elasticity, so that the battery cell separator structure can be deformed when squeezed, thereby buffering the expansion of the battery cell. On the other hand, the lithium replenishing layer can slowly release lithium ions to replenish the electrolyte, thereby improving the conductivity of the electrolyte. At the same time, the film consumption during the charging and discharging process helps to reduce impedance and improve the cycle performance. In this way, as the battery cell expands and contracts during the cycle, the battery cell separator structure is compressed and expanded accordingly, ensuring that the battery cell is always subjected to sufficient pressure during the cycle, and as the cycle proceeds, the battery cell separator structure can replenish lithium ions, thereby having a stronger effect on improving the cycle of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0016] Figure 1 The schematic diagram of the structure of the dual-cell battery of the utility model is shown;

[0017] Figure 2 A schematic diagram of the structure of a single-cell battery is shown;

[0018] Figure 3 A schematic diagram of the structure of a four-cell battery is shown;

[0019] Figure 4 shows the four-cell battery with Figure 3 Another structural diagram of a different type;

[0020] Figure 5 A schematic diagram showing the structure of a battery cell separator structure with two lithium supplement layers;

[0021] Figure 6 Shows that different from Figure 5 A schematic diagram of another battery cell separator structure with two lithium supplement layers;

[0022] Figure 7 A schematic diagram showing the structure of a battery cell separator structure with three lithium supplement layers is shown;

[0023] Figure 8 A schematic structural diagram of a battery cell separator structure with a single lithium supplement layer is shown.

[0024] The above drawings include the following reference numerals:

[0025] 10. Battery cell separator structure; 11. Elastic layer; 12. Lithium replenishing layer; 20. Battery cell. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present utility model will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0028] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0029] In order to solve the problem of poor cycle life of battery cells in the prior art, the utility model provides a battery cell separator structure and a battery.

[0030] like Figures 1 to 8 The battery cell separator structure 10 includes an elastic layer 11 and a lithium replenishing layer 12. There are multiple elastic layers 11, and the elastic layers 11 and the lithium replenishing layers 12 are stacked. Along the stacking direction of the elastic layers 11 and the lithium replenishing layers 12, the two outermost sides of the battery cell separator structure 10 are both elastic layers 11.

[0031] In this embodiment, a cell separator structure 10 having an elastic layer 11 and a lithium replenishing layer 12 is provided. The elastic layer 11 can be used to buffer the expansion of the cell 20, and the lithium replenishing layer 12 is used to release lithium ions into the cell 20, thereby improving the cycle life of the cell 20. Specifically, the cell separator structure 10 can have one or more lithium replenishing layers 12 and two or more elastic layers 11. The two surfaces perpendicular to the stacking direction of the elastic layer 11 and the lithium replenishing layer 12 are the elastic layers 11. On the one hand, the elastic layer 11 has high elasticity. As the cell 20 expands, the cell separator structure 10 is squeezed. On the other hand, the lithium replenishing layer 12 can slowly release lithium ions to replenish the electrolyte, thereby improving the conductivity of the electrolyte. At the same time, the film consumption during the charging and discharging process helps to reduce impedance and improve the cycle performance. In this way, as the battery cell 20 expands and contracts during the cycle, the battery cell separator structure 10 is compressed and expanded accordingly, ensuring that the battery cell 20 is always subjected to sufficient pressure during the cycle. Moreover, as the cycle proceeds, the battery cell separator structure 10 can replenish lithium ions, thereby having a stronger effect on improving the cycle of the battery cell 20.

[0032] In this embodiment, there are multiple lithium replenishing layers 12, and at least two lithium replenishing layers 12 are arranged in contact with each other; of course, it can also be arranged that at least one elastic layer 11 is arranged between at least two adjacent lithium replenishing layers 12, that is, the lithium replenishing layers 12 can be adjacent to each other or separated by the elastic layer 11, such as Figure 5 and Figure 6 The specific number of lithium replenishing layers 12 can also be set as needed, and two can be set, such as Figure 5 and Figure 6 As shown in ; you can also set three, such as Figure 7 More layers may also be provided. Of course, the number of lithium replenishing layers 12 may be provided with one, such as Figure 8 The specific arrangement of the lithium replenishing layer 12 in this embodiment lists three configurations, namely, the two outermost layers of the battery cell separator structure 10 are elastic layers 11, and the two middle layers are adjacent lithium replenishing layers 12, that is, Figure 5 the other is a five-layer structure, the elastic layer 11 and the lithium replenishing layer 12 are alternately arranged and the two outermost elastic layers 11, that is, Figure 6 Another structure is a total of seven layers, the elastic layer 11 and the lithium replenishing layer 12 are alternately arranged and the two outermost elastic layers 11, that is, Figure 7 Of course, there are many practical applications, not limited to these three settings. The adjacent lithium replenishing layers 12 in the middle can also be set to more than two layers, and the elastic layers 11 and lithium replenishing layers 12 alternately arranged in the middle can also be set to more than five layers. It should be noted that the two outermost sides of the battery cell separator structure 10 refer to the two outer surfaces perpendicular to the stacking direction of the elastic layer 11 and the lithium replenishing layer 12, that is, the left and right sides in the figure.

[0033] In this embodiment, the elastic layer 11 is a porous liquid-absorbing structure. Specifically, the porous liquid-absorbing structure can be made of one or more of resin, polypropylene, polyethylene, ethylene-vinyl acetate copolymer, polyurethane, rubber, and silicone, so that the elastic layer 11 has high elasticity and high electrolyte wettability, thereby making the battery cell separator structure 10 have good shrinkage and expansion capabilities, and absorb and release electrolyte into the battery cell 20, thereby improving the cycle performance of the battery cell 20. Of course, the specific type of the elastic layer 11 is not limited to these materials, as long as the functions of the elastic layer 11 can be achieved.

[0034] In this embodiment, the lithium supplement layer 12 includes a lithium supplement material, so that when the lithium supplement layer 12 is placed in the surrounding environment of the battery cell 20, lithium ions can be precipitated and then added to the electrolyte to improve the cycle performance of the battery cell 20. The lithium supplement material may include at least one of a lithium phosphate layer, a lithium fluoride layer, a lithium oxalate layer, and a lithium carbonate layer, which are all commonly used lithium supplement materials and are not described in detail here.

[0035] In this embodiment, the thickness of all elastic layers 11 and lithium replenishing layers 12 along the stacking direction is 1 mm to 1 cm, that is, the thickness of the battery cell separator structure 10 formed by the elastic layers 11 and the lithium replenishing layers 12 is 1 mm to 1 cm. In actual design, the number and thickness of the elastic layers 11 and the lithium replenishing layers 12 can be set according to the requirements of buffering and lithium replenishment. The thickness of different elastic layers 11 and the thickness of different lithium replenishing layers 12 can be the same or different.

[0036] The preparation method of the lithium replenishing layer 12 of this embodiment is to soak the battery cell separator structure 10 containing only the elastic layer 11 in a saturated soluble lithium salt solution in a temperature range of 20°C to 60°C for 12 to 48 hours, and then adjust the temperature to -30°C to -10°C and leave it for 6 to 12 hours, so that the lithium salt will precipitate onto the surface of the elastic layer to form the lithium replenishing layer 12.

[0037] like Figures 1 to 4As shown, this embodiment also provides a battery, including a battery cell 20, a shell and the above-mentioned battery cell separator structure 10, wherein the battery cell 20 is arranged in the shell; the battery cell separator structure 10 is arranged between two battery cells 20; and / or the battery cell separator structure 10 is arranged between the battery cell 20 and the shell. In this way, when the battery cell 20 shrinks or expands, the battery cell separator structure 10 shrinks or expands accordingly, ensuring that the battery cell 20 is subjected to sufficient pressure during the cycle, and absorbs and releases electrolyte, and at the same time replenishes lithium ions into the electrolyte, ensuring good cycle performance of the battery cell 20. In this embodiment, a cell separator structure 10 is preferably provided between the two battery cells 20 and between the battery cell 20 and the outer shell. In this way, the cell separator structure 10 between the battery cells 20 can realize the pressure release and lithium replenishment effect of the internal battery cell 20, while the cell separator structure 10 between the battery cell 20 and the outer shell prevents the battery cell 20 and the outer shell from directly contacting each other, but uses the cell separator structure 10 as a gap. Therefore, when the battery is subjected to external force, the external force directly acts on the cell separator structure 10 through the outer shell, so that the cell separator structure 10 between the battery cell 20 and the outer shell can play a role in time, adjust the electrolyte and release lithium ions, and ensure that the cell separator structure 10 can fully exert its effect.

[0038] Preferably, there are multiple cell separator structures 10 in this embodiment, and a cell separator structure 10 is provided on at least one side of each cell 20, so as to ensure that each cell 20 has a corresponding cell separator structure 10 to act on it when it expands. Furthermore, the cell separator structure 10 is provided on one side of at least one large surface (i.e., the side with the largest surface area of ​​the cell 20) of the cell 20. Since the large surface of the cell is prone to expansion and deformation, the cell separator structure 10 is provided on one side of the large surface to better buffer the expansion of the cell.

[0039] Further preferably, a cell separator structure 10 is disposed on two opposite sides of each cell 20, and the cell separator structure 10 covers the entire side of the cell 20. Figure 2 In the single-cell structure shown, the cell partition structure 10 is arranged on the left and right sides of the battery cell 20, and the surface area of ​​the battery cell partition structure 10 in contact with the battery cell 20 is not less than that of the battery cell 20, so that each position on the side of the battery cell 20 can generate pressure on the cell partition structure 10, so that the cell partition structure 10 can act evenly on the entire side of the battery cell 20, thereby improving the cycle performance of the battery cell 20.

[0040] In addition to providing a plurality of battery cell separator structures 10, a plurality of battery cells 20 may also be provided, and each battery cell 20 is stacked. Figure 1 In addition to the arrangement of at least one cell separator structure 10 between at least two adjacent cells 20, it is also possible to adopt Figure 3In other words, when multiple battery cells 20 are stacked, a battery cell separator structure 10 may be provided between adjacent battery cells 20, or a battery cell separator structure 10 may not be provided, depending on the needs. Moreover, the above two configurations do not conflict and can exist in one battery at the same time.

[0041] Similar to the thickness settings of the elastic layers 11 and the lithium replenishing layers 12 described above, the thicknesses of the battery cell separator structure 10 at different positions may also be different, so that it can adapt to different application scenarios.

[0042] It should be noted that, the multiple in the above embodiments refers to at least two.

[0043] From the above description, it can be seen that the above embodiments of the utility model achieve the following technical effects:

[0044] 1. Solved the problem of poor battery cycle life;

[0045] 2. The elastic layer has high elasticity, so that the cell separator structure can be deformed when squeezed, thereby buffering the expansion of the cell;

[0046] 3. The lithium replenishment layer can slowly release lithium ions into the electrolyte, thereby improving the conductivity of the electrolyte. At the same time, the film consumption during the charge and discharge process helps to reduce impedance and improve cycle performance.

[0047] Obviously, the embodiments described above are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0048] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0050] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A cell separator structure, characterized in that: include: An elastic layer (11), wherein the elastic layer (11) is a plurality of layers; A lithium replenishing layer (12), wherein the elastic layer (11) and the lithium replenishing layer (12) are stacked; Along the stacking direction of the elastic layer (11) and the lithium replenishing layer (12), the two outermost sides of the battery cell separator structure (10) are both the elastic layer (11).

2. The battery cell separator structure according to claim 1, characterized in that: There are a plurality of lithium replenishing layers (12), and at least two of the lithium replenishing layers (12) are arranged in contact with each other.

3. The battery cell separator structure according to claim 1, characterized in that: There are a plurality of lithium replenishing layers (12), and at least one elastic layer (11) is arranged between at least two adjacent lithium replenishing layers (12).

4. The battery cell separator structure according to claim 1, characterized in that: The elastic layer (11) is a porous liquid-absorbing structure.

5. The battery cell separator structure according to claim 1, characterized in that: The thickness of all the elastic layers (11) and the lithium replenishing layers (12) formed along the stacking direction is 1 mm to 1 cm.

6. A battery, characterized in that: include: Battery cell (20); a housing, wherein the battery cell (20) is arranged in the housing; The battery cell separator structure (10) according to any one of claims 1 to 5, wherein the battery cell separator structure (10) is arranged between two of the battery cells (20); and / or the battery cell separator structure (10) is arranged between the battery cell (20) and the casing.

7. The battery according to claim 6, characterized in that The battery cell separator structure (10) is provided on at least one side of each battery cell (20).

8. The battery according to claim 7, characterized in that The battery cell partition structure (10) is provided on two opposite sides of each battery cell (20).

9. The battery according to claim 7, characterized in that The battery cell separator structure (10) covers the entire side surface of the battery cell (20).

10. The battery according to claim 7, characterized in that The battery cell separator structure (10) is arranged on one side of at least one large surface of the battery cell (20).

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