A laminated cell structure and a battery

Abstract

The utility model belongs to the technical field of battery production and manufacture, concretely relates to a kind of lamination cell structure and battery, including first pole piece, second pole piece and diaphragm, multiple the first pole piece, multiple the diaphragm and multiple the second pole piece are alternately stacked in sequence and constitute cell body;The cell body has the first face and the second face opposite in thickness direction;At least one of the first face and the second face has recess, and n hot melt adhesives are arranged in the recess, and n is the integer greater than or equal to 1.The utility model optimizes cell structure, solves the problem that adhesive paper occupies battery internal space, and helps to improve the volumetric energy density of battery.

Description

Technical Field

[0001] This utility model belongs to the technical field of battery manufacturing, specifically relating to a stacked cell structure and a battery. Background Technology

[0002] Lithium-ion batteries, as a new type of rechargeable battery, have advantages such as high energy density and power density, high operating voltage, light weight, small size, long cycle life, good safety, and environmental friendliness. They have broad application prospects in portable electrical appliances, power tools, large-scale energy storage, and electric transportation power sources.

[0003] Consumer battery cells have increasingly higher energy density requirements, and mobile phones are using more and more irregularly shaped battery structures, so stacked battery cells are gradually increasing their market share.

[0004] In the process of realizing this utility model, the inventors discovered that the prior art has at least the following problems:

[0005] Existing stacked cells require adhesive tape for fixation during manufacturing, which occupies internal space and compresses the active material area, resulting in a decrease in the volumetric energy density of the battery. Utility Model Content

[0006] One of the objectives of this invention is to address the shortcomings of existing technologies by providing a stacked cell structure. By optimizing the cell structure, the problem of adhesive tape occupying internal battery space is solved, which helps to improve the volumetric energy density of the battery.

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

[0008] A stacked battery cell structure includes a first electrode, a second electrode, and a separator. A plurality of first electrodes, a plurality of separators, and a plurality of second electrodes are alternately stacked to form a battery cell body. The battery cell body has a first surface and a second surface opposite to each other in the thickness direction. At least one of the first surface and the second surface has a groove, and n hot melt adhesives are disposed in the groove, where n is an integer ≥1.

[0009] In some possible implementations, both the first electrode and the second electrode include a foil and an active material layer. The first electrode or the second electrode located on the outer layer of the cell body is divided into a coated surface and an empty foil surface. The foil on the coated surface is coated with the active material layer, and the foil on the empty foil surface is exposed on the surface of the first surface or the second surface.

[0010] In some possible implementations, the depth of the groove is Aw, and the thickness of the hot melt adhesive is Ts, satisfying the relationship: Aw = Ts - A, where 0.001mm ≤ A ≤ 0.2mm.

[0011] In some possible implementations, the width of the groove is Ww, the width of the foil is W, and the width of the hot melt adhesive is Ws, satisfying the relationship: Ww=Wn*Ws-X, where 10mm≤X≤15mm.

[0012] In some possible implementations, the length of the groove is Lw, the length of the foil is L, and the length of the hot melt adhesive is Ls, satisfying the relationship: Lw=L-Ls-C, where 10mm≤C≤30mm.

[0013] In some possible implementations, the foil thickness of the first electrode located in the inner layer of the battery cell body is less than the foil thickness of the first electrode located in the outer layer of the battery cell body.

[0014] In some possible implementations, there are multiple grooves, and each groove is provided with n hot melt adhesives.

[0015] In some possible implementations, the foil is a copper foil or an aluminum foil.

[0016] In some possible implementations, the projection of the hot melt adhesive on the first surface at least partially overlaps with the projection of the hot melt adhesive on the second surface.

[0017] The second objective of this utility model is to provide a battery, including a cover plate, a shell, and the aforementioned stacked cell structure, wherein the first side of the cell body is bonded to the cover plate by hot melt adhesive, and the second side of the cell body is bonded to the shell by hot melt adhesive.

[0018] One of the above technical solutions has the following beneficial effects:

[0019] This invention optimizes the cell structure by designing a groove on at least one of the first and second surfaces of the cell body. The groove can accommodate hot melt adhesive, which helps to reduce the height of the hot melt adhesive in the thickness direction of the cell and improve the space utilization rate of the cell in the thickness direction. This solves the problem of hot melt adhesive occupying the internal space of the battery. Compared with the existing structure, the cell body of this invention can be designed to be thicker without changing the total thickness of the battery, thereby improving the volumetric energy density of the battery. Attached Figure Description

[0020] The features, advantages and technical effects of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the structure of the battery cell body of this utility model.

[0022] Figure 2 This is a top view of the battery cell body of this utility model.

[0023] Figure 3 This is a cross-sectional structural diagram of the battery cell body of this utility model.

[0024] Figure 4 for Figure 3 Enlarged view of point A.

[0025] Figure 5 This is a schematic diagram of the battery structure of this utility model.

[0026] The reference numerals in the attached figures are explained as follows:

[0027] 1-First electrode;

[0028] 2-Second pole sheet;

[0029] 3-Cell body; 31-First side; 32-Second side;

[0030] 4-groove;

[0031] 5-Hot melt adhesive;

[0032] 6-Foil;

[0033] 7-Cover plate;

[0034] 8-Shell;

[0035] A - Thickness direction. Detailed Implementation

[0036] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0037] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be interpreted as indicating or implying relative importance.

[0038] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0039] The present invention will be further described in detail below with reference to the accompanying drawings, but this is not intended to limit the present invention.

[0040] Example 1

[0041] Because existing stacked cells need to be fixed with adhesive tape during the manufacturing process, they occupy the internal space of the battery and compress the active material area, resulting in a decrease in the volumetric energy density of the battery.

[0042] like Figures 1-5 As shown, the stacked cell structure of this utility model includes a first electrode 1, a second electrode 2, and a separator. Multiple first electrode 1s, multiple separators, and multiple second electrode 2 are alternately stacked to form a cell body 3. The cell body 3 has a first surface 31 and a second surface 32 opposite each other in the thickness direction A. At least one of the first surface 31 and the second surface 32 has a groove 4, and n hot melt adhesives 5 are disposed within the groove 4, where n is an integer ≥ 1. This utility model optimizes the cell structure by designing a groove 4 in at least one of the first surface 31 and the second surface 32 of the cell body 3. The groove 4 can accommodate the hot melt adhesives 5, which helps to reduce the height of the hot melt adhesives 5 in the thickness direction A of the cell, improves the space utilization rate of the cell in the thickness direction A, and solves the problem of the hot melt adhesives 5 occupying internal battery space. Compared with existing structures, without changing the total battery thickness, the cell body 3 of this utility model can be designed to be thicker, thereby increasing the volumetric energy density of the battery.

[0043] It should be noted that: See Figure 1As shown, the number of hot melt adhesives 5 is preferably 2, n=2. In other embodiments, n can also be 1, 2, 3, 4, etc., which is not limited here. The stacking method of the battery cell body 3 can be understood as alternatingly stacking a first electrode 1, a separator, and a second electrode 2. The first electrode 1 and the second electrode 2 are positive and negative electrodes with opposite polarities. To avoid short circuits between positive and negative electrodes, a separator is provided between each pair of adjacent electrodes, and the electrodes with opposite polarities are electrically isolated by the separator. The first electrode 1 can be a positive electrode or a cathode, and the second electrode 2 can be a negative electrode or an anode; or, the first electrode 1 can be a negative electrode or an anode, and the second electrode 2 can be a positive electrode or a cathode, which is not limited here. The battery cell body 3 includes anode active material, copper foil, separator, cathode active material, aluminum foil, etc. The anode active material is bonded to the copper foil with an adhesive to form an anode electrode. The cathode active material is bonded to the aluminum foil with an adhesive to form a cathode electrode. The cathode, anode, and separator are formed by hot pressing to form the battery cell body 3. The hot melt adhesive 5 is a SIS hot melt adhesive, which can be bonded to the battery cover 7 and casing 8.

[0044] In the stacked cell structure according to this utility model, both the first electrode 1 and the second electrode 2 include a foil 6 and an active material layer. The first electrode 1, located on the outer layer of the cell body 3, is divided into a coated surface and an empty foil surface. The foil 6 on the coated surface is coated with an active material layer, and the foil 6 on the empty foil surface is exposed on the surface of the first surface 31 or the second surface 32. In this embodiment, since the cell body 3 is a stacked structure, the cell body 3 has two outer layers. One of the outer layers of the cell body 3 is the first electrode 1, which is the anode. This anode layer has a single-sided active material coating structure. The foil 6 of this anode layer is a copper foil. One side of the foil 6 of this anode layer is exposed on the surface of the first surface 31 and is designed with a groove 4, that is, a groove 4 is designed corresponding to the first surface 31. The groove 4 can accommodate two hot melt adhesives 5. The other side of the foil 6 of this anode layer faces the inside of the cell body 3 and is coated with an anode active material. Similarly, another outer layer located on the cell body 3 is also the first electrode 1. One side of the foil 6 of the anode in this layer is exposed on the surface of the second surface 32 and is designed with a groove 4, that is, the groove 4 is designed corresponding to the second surface 32. In addition, the inner layer can be understood as all the layers located between the two outer layers mentioned above. The anode located in the inner layer of the cell body 3 is a double-sided coated active material, and the cathode located in the inner layer of the cell body 3 is also a double-sided coated active material.

[0045] In the stacked cell structure according to this utility model, the depth of the groove 4 is Aw, and the thickness of the hot melt adhesive 5 is Ts, satisfying the relationship: Aw=Ts-A, where 0.001mm≤A≤0.2mm. For example, the depth of groove 4 is Aw = Ts-0.001mm, Ts-0.01mm, Ts-0.02mm, Ts-0.03mm, Ts-0.04mm, Ts-0.05mm, Ts-0.06mm, Ts-0.07mm, Ts-0.08mm, Ts-0.09mm, Ts-0.1mm, Ts-0.11mm, Ts-0.12mm, Ts-0.13mm, Ts-0.14mm, Ts-0.15mm, Ts-0.16mm, Ts-0.17mm, Ts-0.18mm, Ts-0.19mm, or Ts-0.2mm, etc., to avoid the groove 4 being too deep, which helps to reduce the impact of the thickness of hot melt adhesive 5 on the overall thickness of the battery.

[0046] In the stacked cell structure according to this utility model, the width of the groove 4 is Ww, the width of the foil 6 is W, and the width of the hot melt adhesive 5 is Ws, satisfying the relationship: Ww=Wn*Ws-X, where 10mm≤X≤15mm. See also Figure 1 As shown, in this embodiment, the number of hot melt adhesives 5 is preferably two, where n = 2. Therefore, the width of the groove 4 can be Ww = W - 2 * Ws - 10 mm, W - 2 * Ws - 11 mm, W - 2 * Ws - 12 mm, W - 2 * Ws - 13 mm, W - 2 * Ws - 14 mm, or W - 2 * Ws - 15 mm, etc., to avoid the groove 4 being too narrow, which would affect the hot melt adhesive 5 being contained within the groove 4. In other embodiments, the width W of the foil 6 satisfies: 30 mm ≤ W ≤ 75 mm. For example, the width W of the foil 6 is 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, or 75 mm, etc., to avoid the foil 6 being too narrow, which would affect the assembly effect of the hot melt adhesive 5. The width of the hot melt adhesive 5, Ws, satisfies the following condition: 10mm≤Ws≤30mm. For example, the width of the hot melt adhesive 5 can be Ws = 10mm, 15mm, 20mm, 25mm, or 30mm, etc., to avoid the hot melt adhesive 5 being too wide, causing it to exceed the range of the groove 4 and affecting the assembly effect of the hot melt adhesive 5.

[0047] In the stacked cell structure according to this utility model, the length of the groove 4 is Lw, the length of the foil 6 is L, and the length of the hot melt adhesive 5 is Ls, satisfying the relationship: Lw = L - Ls - C, where 10mm ≤ C ≤ 30mm. In this embodiment, the length of the groove 4 is Lw = L - Ls - 10mm, L - Ls - 15mm, L - Ls - 20mm, L - Ls - 25mm, or L - Ls - 30mm, etc., to avoid the length of the groove 4 being too small, which would affect the hot melt adhesive 5 being housed within the groove 4. In other embodiments, the length L of the foil 6 satisfies: 40mm ≤ L ≤ 120mm, for example, the length L of the foil 6 is 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, or 120mm, etc., to avoid the width of the foil 6 being too small, which would affect the assembly effect of the hot melt adhesive 5. The length Ls of the hot melt adhesive 5 should satisfy: 30mm≤Ls≤90mm. For example, the length Ls of the hot melt adhesive 5 can be 30mm, 40mm, 50mm, 60mm, 70mm, 80mm or 90mm, etc., to avoid the hot melt adhesive 5 being too long, causing it to exceed the range of the groove 4 and affecting the assembly effect of the hot melt adhesive 5.

[0048] In the stacked cell structure according to this utility model, the thickness of the foil 6 of the first electrode 1 located in the inner layer of the cell body 3 is less than the thickness of the foil 6 of the first electrode 1 located in the outer layer of the cell body 3. Since the cell body 3 is encapsulated by a steel shell, the stacked cell is subjected to compression from the steel shell during expansion, leading to a risk of cracking in the outer foil. Furthermore, the high rigidity of the steel shell around its perimeter prevents the core from deforming synchronously with its edges, causing the foil at the cell edges to be subjected to compression stress, resulting in cracking during cyclic expansion. In this utility model, the thickness of the foil 6 of the first electrode 1 in the outer layer is 2 to 10 times that of the inner foil 6, which improves the rigidity of the foil structure, solves the problem of foil cracking caused by compression from the outer shell around the outer foil during cyclic expansion, and helps reduce the risk of foil cracking. Specifically, since the foil 6 of the first electrode 1 located on the outer layer of the battery cell body 3 has a groove 4 in the center, the edge thickness of the foil 6 of the first electrode 1 is greater than the thickness at the groove 4 of the foil 6. That is, the edge of the foil 6 of the first electrode 1 is thicker and also thicker than the foil 6 of the first electrode 1 located on the inner layer of the battery cell body 3. At the same time, since the edge of the foil 6 of the first electrode 1 corresponds to the surrounding area with greater rigidity of the steel shell, by increasing the edge thickness of the foil 6, the edge structural rigidity of the foil 6 is improved, thereby avoiding the foil at the edge of the battery cell being squeezed and stressed, which would cause the foil to crack during the cyclic expansion process.

[0049] In the stacked cell structure according to this utility model, there are multiple grooves 4, and each groove 4 is provided with n hot melt adhesives 5. In this embodiment, there are one or more grooves 4 for assembling hot melt adhesives. The number of grooves 4 can be adjusted according to the actual size of the battery, and is not limited here. The hot melt adhesives 5 in the grooves 4 can be designed to be arranged at equal intervals, so that the hot melt adhesives 5 are bonded more evenly, which helps to improve the bonding stability of the hot melt adhesives 5 with the battery cover plate 7 and the casing 8.

[0050] The working principle of this utility model is as follows:

[0051] This invention optimizes the cell structure by designing a groove 4 on at least one of the first surface 31 and the second surface 32 of the cell body 3. The groove 4 can accommodate the hot melt adhesive 5, which helps to reduce the height of the hot melt adhesive 5 in the thickness direction A of the cell, improves the space utilization rate of the cell in the thickness direction A, and solves the problem of the hot melt adhesive 5 occupying the internal space of the battery. Compared with the existing structure, the cell body 3 of this invention can be designed to be thicker without changing the total thickness of the battery, thereby improving the volumetric energy density of the battery.

[0052] Example 2

[0053] Unlike Embodiment 1, in this embodiment, the second electrode 2 located on the outer layer of the cell body 3 is divided into a coated surface and an empty foil surface. The foil 6 on the coated surface is coated with an active material layer, and the foil 6 on the empty foil surface is exposed on the surface of the first surface 31 or the second surface 32. In this embodiment, the cell body 3 has two outer layers. One of the outer layers of the cell body 3 is the second electrode 2, which is the cathode. This cathode layer has a single-sided active material coating structure, and the foil 6 of this cathode layer is aluminum foil. One side of the foil 6 of this cathode layer is exposed on the surface of the first surface 31 and is designed with a groove 4, that is, the groove 4 is designed corresponding to the first surface 31. The groove 4 can accommodate two hot melt adhesives 5. The other side of the foil 6 of this cathode layer faces the inside of the cell body 3 and is coated with cathode active material. Similarly, the other outer layer of the cell body 3 is also a second electrode 2. One side of the foil 6 of this cathode layer is exposed on the surface of the second surface 32 and is designed with a groove 4, that is, the groove 4 is designed corresponding to the second surface 32. In addition, the thickness of the foil 6 of the second electrode 2 located in the inner layer of the cell body 3 is smaller than that of the foil 6 of the second electrode 2 located in the outer layer of the cell body 3. This can also improve the rigidity of the foil structure, solve the problem of foil being squeezed by the outer shell during the cyclic expansion of the outer foil, and help reduce the risk of foil cracking.

[0054] The other structures are the same as in Embodiment 1, and will not be described again here.

[0055] Example 3

[0056] Unlike Embodiment 1, in this embodiment, the projection of the hot melt adhesive 5 on the first surface 31 at least partially overlaps with the projection of the hot melt adhesive 5 on the second surface 32. In this embodiment, the overlap of the projections of the two hot melt adhesives 5 on the first surface 31 and the two hot melt adhesives 5 on the second surface 32 facilitates standardized production and improves the production efficiency of the battery cells. In other embodiments, the projections of the hot melt adhesive 5 on the first surface 31 and the hot melt adhesive 5 on the second surface 32 may also partially overlap; this is not a limitation, as long as the hot melt adhesive 5 is bonded to the battery cover 7 and casing 8.

[0057] The other structures are the same as in Embodiment 1, and will not be described again here.

[0058] Battery

[0059] The battery includes a cover plate 7, a housing 8, and the aforementioned stacked cell structure. The first surface 31 of the cell body 3 is bonded to the cover plate 7 by hot melt adhesive 5, and the second surface 32 of the cell body 3 is bonded to the housing 8 by hot melt adhesive 5.

[0060] Specifically, the first surface 31 is the empty foil surface of the first electrode 1 of one of the outer layers of the cell body 3, and the second surface 32 is the empty foil surface of the first electrode 1 of the other outer layer of the cell body 3. By designing grooves 4 on the first surface 31 and the second surface 32, the grooves 4 can accommodate hot melt adhesive 5. The hot melt adhesive 5 on the first surface 31 is bonded to the cover plate 7, and the hot melt adhesive 5 on the second surface 32 is bonded to the shell 8. This helps to reduce the height of the hot melt adhesive 5 in the thickness direction A of the cell, improve the space utilization rate of the cell in the thickness direction A, and solve the problem of the hot melt adhesive 5 occupying the internal space of the battery.

[0061] In addition, the housing 8 has an outer edge that extends downward to form an opening. The side wall of the housing 8 is designed with positive and negative electrode adapter plates and aluminum busbars. The cover plate 7 has a planar structure and covers the opening of the housing 8, so that the cover plate 7 and the housing 8 form a storage cavity. The battery cell body 3 is designed inside the storage cavity.

[0062] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on this utility model are within the protection scope of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.

Claims

1. A stacked battery cell structure, characterized in that, The battery cell body (3) consists of a first electrode (1), a second electrode (2), and a separator. Multiple first electrodes (1), multiple separators, and multiple second electrodes (2) are stacked alternately in sequence. The battery cell body (3) has a first surface (31) and a second surface (32) opposite to each other in the thickness direction; at least one of the first surface (31) and the second surface (32) has a groove (4) in which n hot melt adhesives (5) are disposed, where n is an integer ≥1.

2. The stacked cell structure as described in claim 1, characterized in that: Both the first electrode (1) and the second electrode (2) include a foil (6) and an active material layer. The first electrode (1) or the second electrode (2) located on the outer layer of the battery cell body (3) is divided into a coated surface and an empty foil surface. The foil (6) on the coated surface is coated with the active material layer, and the foil (6) on the empty foil surface is exposed on the surface of the first surface (31) or the second surface (32).

3. The stacked cell structure as described in claim 2, characterized in that: The depth of the groove (4) is Aw, and the thickness of the hot melt adhesive (5) is Ts, satisfying the relationship: Aw=Ts-A, where 0.001mm≤A≤0.2mm.

4. The stacked cell structure as described in claim 2, characterized in that: The width of the groove (4) is Ww, the width of the foil (6) is W, and the width of the hot melt adhesive (5) is Ws, satisfying the relationship: Ww=W-nWs-X, where 10mm≤X≤15mm.

5. The stacked cell structure as described in claim 2, characterized in that: The length of the groove (4) is Lw, the length of the foil (6) is L, and the length of the hot melt adhesive (5) is Ls, satisfying the relationship: Lw=L-Ls-C, where 10mm≤C≤30mm.

6. A laminated cell structure as described in any one of claims 1-5, characterized in that: The thickness of the foil (6) of the first electrode (1) located in the inner layer of the battery cell body (3) is less than the thickness of the foil (6) of the first electrode (1) located in the outer layer of the battery cell body (3).

7. A laminated cell structure as described in any one of claims 1-5, characterized in that: The number of grooves (4) is multiple, and each groove (4) is provided with n hot melt adhesives (5).

8. A laminated cell structure as described in any one of claims 2-5, characterized in that: The foil (6) is copper foil or aluminum foil.

9. A stacked cell structure as described in any one of claims 1-5, characterized in that: The projection of the hot melt adhesive (5) located on the first surface (31) at least partially overlaps with the projection of the hot melt adhesive (5) located on the second surface (32).

10. A battery, characterized in that: The battery includes a cover plate (7), a housing (8), and a stacked cell structure as described in any one of claims 1-9. The first side (31) of the cell body (3) is bonded to the cover plate (7) by hot melt adhesive (5), and the second side (32) of the cell body (3) is bonded to the housing (8) by hot melt adhesive (5).

Images