Laminated battery

Abstract

The utility model discloses a laminated battery, which belongs to the technical field of batteries, and comprises a first pole piece and a second pole piece which are alternately laminated; the first pole piece comprises a first current collector, a first material area and a first empty foil area are formed on the first current collector, the first empty foil area is annularly arranged on the first material area, and at least one side, deviating from the first material area, of the first empty foil area is provided with a first tab; the laminated battery further comprises an insulating layer, the insulating layer is arranged in the first empty foil area, the insulating layer comprises a surrounding part and an avoiding part, the surrounding part wraps the edge of the first current collector, and the avoiding part accommodates the first tab; the second pole piece comprises a second current collector and a second tab; and the edge of the second current collector is accommodated in the area where the insulating layer is located. The surrounding part wraps burrs at the edge of the first current collector, the edge of the second current collector is contained in the area where the insulating layer is located, burrs of the second pole piece can be prevented from making contact with the first current collector, burr isolation is achieved, and the short circuit problem of the battery is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of battery, especially a laminated battery. BACKGROUND

[0002] With the large-scale use of lithium ion batteries, the requirements for manufacturing cost and energy density are also increasing. The traditional liquid battery has the disadvantage of low energy density, because the size of the separator in the battery structure is larger than that of the pole piece, resulting in the decrease of the weight energy density and the volume energy density of the battery. The solid-state battery adopts a separator-free laminated design, which improves the energy density of the battery by removing the separator.

[0003] In the production process of the solid-state battery, the positive pole piece and the negative pole piece are cut from the roll material by die cutting to meet the size or shape required by production. In the process of die cutting, burrs will be generated at the edge of the pole piece. After the positive pole piece and the negative pole piece are assembled and attached without a separator, the burrs are easy to pierce the opposite pole piece, causing the battery to short circuit, resulting in safety hazards and affecting the service life of the battery. SUMMARY

[0004] The utility model aims at providing a laminated battery to solve the technical problem that the burrs at the edge of the pole piece in the prior art easily cause the battery to short circuit.

[0005] According to the above idea, the technical scheme adopted by the utility model is as follows:

[0006] A laminated battery comprises a first pole piece and a second pole piece, the first pole piece and the second pole piece are alternately and layerwisely arranged;

[0007] The first pole piece comprises a first current collector, a first material area and a first empty foil area are formed on the first current collector, the first empty foil area is annularly arranged on the first material area, and at least one side of the first empty foil area away from the first material area is provided with a first tab;

[0008] The laminated battery further comprises an insulating layer, the insulating layer is arranged on the first empty foil area, and the insulating layer comprises a surrounding part and a avoiding part, the surrounding part wraps the edge of the first current collector, and the avoiding part accommodates the first tab;

[0009] The second pole piece comprises a second current collector and a second tab, and the edge of the second current collector is accommodated in the area where the insulating layer is located.

[0010] As a preferred, the cross-sectional shape of the insulating layer is U-shaped along the direction perpendicular to the surface of the first current collector.

[0011] Preferably, the first material area is provided with a first active material layer, and the inner side edge of the insulating layer abuts against the first active material layer.

[0012] Preferably, the first empty foil area has a width of 0.5-1.5 mm.

[0013] Preferably, the first material area is provided with a first active material layer, and the thickness of the insulating layer is less than or equal to the thickness of the first active material layer.

[0014] Preferably, the first empty foil area is provided with an insulating tape on both sides in the thickness direction of the first tab, the insulating tape covers the avoiding part and part of the first tab, and the two ends of the insulating tape are overlapped with the surrounding part.

[0015] Preferably, in the direction away from the first material area, the size of the insulating tape covering the first tab is 0.5-2 mm; and / or, the distance between each end of the insulating tape and the surrounding part is 0.5-2 mm.

[0016] Preferably, the length of the first current collector is equal to the length of the second current collector, and the width of the first current collector is equal to the width of the second current collector.

[0017] Preferably, the second current collector is provided with a second material area and a second empty foil area, the second empty foil area is annularly arranged on the second material area, at least one side of the second empty foil area away from the second material area is provided with the second tab, the second empty foil area is provided with the insulating layer, the surrounding part wraps the edge of the second current collector, and the avoiding part accommodates the second tab.

[0018] Preferably, the first tab is a positive electrode tab, and the second tab is a negative electrode tab; or, the first tab is a negative electrode tab, and the second tab is a positive electrode tab.

[0019] The utility model discloses a beneficial effect:

[0020] The utility model discloses a laminated battery, a first material area and a first empty foil area are formed on the first current collector, the first empty foil area is annularly arranged on the first material area, an insulating layer is arranged on the first empty foil area, and the insulating layer comprises a surrounding part and an avoiding part, the surrounding part wraps the edge of the first current collector, and the avoiding part accommodates the first tab, so that burrs at the edge of the first current collector are wrapped, the edge of the second current collector is accommodated in the area where the insulating layer is located, burrs of the second tab can be blocked from contacting the first current collector, the isolation of the burrs is realized, and the problem of battery short circuit is avoided, the process of arranging the insulating layer on the first empty foil area is simple, and the cost is greatly reduced. DRAWINGS

[0021] Figure 1is a first schematic view of the first pole piece provided by the embodiment one of the utility model;

[0022] Figure 2 is a second schematic view of the first pole piece provided by the embodiment one of the utility model;

[0023] Figure 3 is Figure 2 the A-A direction section view of;

[0024] Figure 4 is a schematic view of the insulating layer provided by the embodiment one of the utility model;

[0025] Figure 5 is a third schematic view of the first pole piece provided by the embodiment one of the utility model;

[0026] Figure 6 is Figure 5 the B-B direction section view of;

[0027] Figure 7 is a first schematic view of the second pole piece provided by the embodiment one of the utility model;

[0028] Figure 8 is a second schematic view of the second pole piece provided by the embodiment one of the utility model;

[0029] Figure 9 is a schematic view of the first pole piece and the second pole piece provided by the embodiment one of the utility model;

[0030] Figure 10 is a first schematic view of the second pole piece provided by the embodiment two of the utility model;

[0031] Figure 11 is a second schematic view of the second pole piece provided by the embodiment two of the utility model;

[0032] Figure 12 is a schematic view of the insulating layer provided by the embodiment two of the utility model;

[0033] Figure 13 is a third schematic view of the second pole piece provided by the embodiment two of the utility model.

[0034] In the figure:

[0035] 10, first pole piece;11, first current collector;111, first material area;112, first empty foil area;12, first pole lug;13, first active material layer;

[0036] 20, second pole piece;21, second current collector;211, second material area;212, second empty foil area;22, second pole lug;23, second active material layer;

[0037] 30, insulating layer; 31, surrounding portion; 32, avoiding portion;

[0038] 40, insulating tape. DETAILED DESCRIPTION

[0039] Embodiments of the present application will be described in detail below with reference to the drawings, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and should not be understood as limiting the present application.

[0040] In the description of the present application, unless explicitly defined and limited otherwise, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0041] In the present application, unless explicitly defined and limited otherwise, the first feature "on" or "below" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0042] The technical scheme of the present application will be further illustrated below by combining the drawings and through specific embodiments.

[0043] Embodiment one

[0044] Referring to Figures 1 to 9 The present embodiment provides a laminated battery, comprising a first pole piece 10 and a second pole piece 20, the first pole piece 10 and the second pole piece 20 are alternately and laminatedly arranged. The first pole piece 10 and the second pole piece 20 can be fixed by bonding.

[0045] The first pole piece 10 comprises a first current collector 11, a first material area 111 and a first empty foil area 112 are formed on the first current collector 11, the first empty foil area 112 is annularly arranged on the first material area 111, and the first empty foil area 112 is provided with a first tab 12 on at least one side away from the first material area 111. In the production process of the first pole piece 10, the first current collector 11 and the first tab 12 are synchronously die-cut from a roll material, which can be single-sided or double-sided to meet the size or shape required by production.

[0046] The laminated battery further comprises an insulation layer 30 arranged on the first empty foil area 112, and the insulation layer 30 comprises a surrounding part 31 and a avoiding part 32, the surrounding part 31 wraps the edge of the first current collector 11, and the avoiding part 32 accommodates the first tab 12. By arranging the insulation layer 30 on the first empty foil area 112, the burrs at the edge of the first current collector 11 are wrapped by the surrounding part 31, and the avoiding part 32 provides a avoiding space for the first tab 12 to avoid interference between the insulation layer 30 and the first tab 12. As shown in Figure 2 and Figure 4 The first pole piece 10 is single-sided, and the avoiding part 32 is located at a position opposite to the first tab 12 on the first empty foil area 112, and the avoiding part 32 can be a notch arranged on the insulation layer 30 to provide a avoiding space for the first tab 12.

[0047] The second pole piece 20 comprises a second current collector 21 and a second tab 22, and the edge of the second current collector 21 is accommodated in an area where the insulation layer 30 is located. In the production process of the second pole piece 20, the second current collector 21 and the second tab 22 are synchronously die-cut from a roll material, which can be single-sided or double-sided to meet the size or shape required by production.

[0048] By accommodating the edge of the second current collector 21 in the area where the insulation layer 30 is located, the burrs of the second pole piece 20 can be prevented from contacting the first current collector 11, thereby achieving isolation of the burrs and avoiding battery short circuit problems. The process of arranging the insulation layer 30 on the first empty foil area 112 is simple, thereby greatly reducing the cost.

[0049] The insulation layer 30 can be a PI tape, a silicone-based material, a fluorinated liquid, a solid electrolyte layer, etc. The solid electrolyte layer can be an oxide or a sulfide, etc. The insulation layer 30 is resistant to high temperature and pressure, and will not dissolve or cause pole piece adhesion after drying under high temperature and pressure.

[0050] In this embodiment, the cross-sectional shape of the insulation layer 30 is U-shaped along the direction perpendicular to the surface of the first current collector 11. As shown in Figure 3As shown, the insulating layer 30 wraps around both sides of the first current collector 11 in the thickness direction, increasing the contact area, achieving full wrapping, and preventing burrs from being exposed. In other embodiments, an insulating layer 30 can be provided on each side of the first current collector 11 in the thickness direction, with the insulating layer 30 protruding from the edge of the first current collector 11, and the two insulating layers 30 bonded to each other.

[0051] Typically, the electrode is a rectangular structure. The two mutually perpendicular directions within the plane of the surface of the first electrode 10 are defined as the X direction and the Y direction, respectively. The X direction and the Y direction are parallel to two adjacent sides of the first electrode 10, and the thickness direction of the first electrode 10 is the Z direction. In other embodiments, the first electrode 10 and the second electrode 20 can also have other shapes, which are not limited to this.

[0052] The edge of the second current collector 21 is contained within the region of the insulating layer 30. The size of the second current collector 21 may be smaller than that of the first current collector 11. For example, the size of the second current collector 21 in the X direction is smaller than that of the first current collector 11 in the X direction, and the size of the second current collector 21 in the Y direction is smaller than that of the first current collector 11 in the Y direction. The edge of the second current collector 21 is located in the middle of the insulating layer 30, or the edge of the second current collector 21 is located in the insulating layer 30 and close to the inner edge of the insulating layer 30, or the edge of the second current collector 21 is located in the insulating layer 30 and close to the outer edge of the insulating layer 30, or the edge of the second current collector 21 is flush with the outer edge of the insulating layer 30.

[0053] In this embodiment, the length of the first current collector 11 is equal to the length of the second current collector 21, and the width of the first current collector 11 is equal to the width of the second current collector 21. That is, the size of the second current collector 21 is equal to the size of the first current collector 11. After the first and second pole pieces 10 and 20 are alternately stacked, no offset or misalignment occurs. Specifically, the size of the second current collector 21 in the X direction is equal to the size of the first current collector 11 in the X direction, and the size of the second current collector 21 in the Y direction is equal to the size of the first current collector 11 in the Y direction.

[0054] The width of the first empty foil area 112 is 0.5-1.5 mm. Figure 1 As shown, D1 represents the width of the first empty foil area 112, and the value of D1 is between 0.5-1.5 mm, for example, 0.5 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm or 1.5 mm. The width range of the first empty foil area 112 is limited to reserve installation space for the insulating layer 30, facilitate the arrangement of the insulating layer 30 in the first empty foil area 112, and ensure the size of the first material area 111 to avoid occupying the size of the first material area 111, resulting in a decrease in the weight energy density and volume energy density of the battery, thereby avoiding a decrease in the battery energy density.

[0055] In the embodiment, the width of the first empty foil area 112 is uniform around the circumference of the first material area 111. In other embodiments, the width of the first empty foil area 112 can be non-uniform around the circumference of the first material area 111, for example, the width of the first empty foil area 112 along the Y direction is greater than the width of the first empty foil area 112 along the X direction.

[0056] The first material area 111 is provided with a first active material layer 13. The first active material layer 13 can adopt an existing coating layer, or the first active material layer 13 adopts an existing solid electrolyte layer, or the first active material layer 13 includes a coating layer and a solid electrolyte layer disposed on the coating layer.

[0057] The inner side edge of the insulating layer 30 abuts against the first active material layer 13, so that the insulating layer 30 and the first active material layer 13 neither overlap nor have a gap, ensuring the flatness of the first pole piece 10. The thickness of the insulating layer 30 is less than or equal to the thickness of the first active material layer 13, so that the edge thickness of the first pole piece 10 is equal to or close to the main body thickness of the first pole piece 10, ensuring the flatness of the first pole piece 10.

[0058] As shown in FIG. 1, the first empty foil area 112 is provided with an insulating tape 40 on both sides in the thickness direction of the first tab 12, the insulating tape 40 covers the avoiding part 32 and covers part of the first tab 12, and the two ends of the insulating tape 40 are overlapped with the surrounding part 31. By setting the insulating tape 40, the position where the insulating layer 30 is disconnected can be connected, and the insulating tape 40 covers the joint area of the first tab 12 and the first current collector 11, so that the edge area of the first current collector 11 is completely covered, thereby blocking the burrs and the like at the edge of the first current collector 11. Figure 5 In the direction away from the first material area 111, the size of the insulating tape 40 covering the first tab 12 is 0.5-2mm. Referring to FIG. 1, D2 represents the size of the insulating tape 40 covering the first tab 12 in the direction away from the first material area 111, and D2 is valued between 0.5-2mm, for example, 0.5mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.8mm or 2mm; limiting the covering size of the insulating tape 40 to the first tab 12, on the one hand, it can increase the contact area of the insulating tape 40 and the first tab 12, so that the insulating tape 40 is difficult to be peeled off, avoiding the short circuit problem, on the other hand, it also ensures the electrical connection range of the first tab 12, avoids the covering size being too large, affecting the electrical connection of the tab, and further causing the battery energy density to be reduced.

[0059] Figure 5 Continuing to see

[0060] Continuing to see Figure 5 ​The two ends of the insulation tape 40 along the X direction are overlapped with the surrounding part 31 to completely cover the avoiding part 32 and the joint area of the first tab 12 and the first current collector 11. The distance of each end of the insulation tape 40 overlapping with the surrounding part 31 can be equal or not equal. Referring to Figure 5 D3 represents the distance of each end of the insulation tape 40 overlapping with the surrounding part 31, and D3 is between 0.5-2mm, for example, 0.5mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.8mm or 2mm. The overlapping size of the insulation tape 40 and the surrounding part 31 is limited to enable the insulation tape 40 to completely cover the joint area of the first tab 12 and the first current collector 11 to prevent short circuit risk in the winding or packaging process, and to avoid too much overlapping range affecting the overall thickness of the first tab 10, thereby increasing the thickness of the battery.

[0061] The thickness of the insulation tape 40 is less than or equal to the thickness of the first active material layer 13 to ensure the flatness of the first tab 10. The insulation tape 40 can be one of PET adhesive paper, PP adhesive paper, PC adhesive paper and PVC adhesive paper, which has excellent tensile strength and adhesive strength, and also has good electrolyte resistance.

[0062] In some embodiments, the first tab 10 is a positive tab, and the second tab 20 is a negative tab. In some embodiments, the first tab 10 is a negative tab, and the second tab 20 is a positive tab. The insulation layer 30 can be provided on the positive tab, or on the negative tab, or on both the positive tab and the negative tab.

[0063] In this embodiment, the first tab 10 is a positive tab, and the second tab 20 is a negative tab. The insulation layer 30 is provided on the first tab 10, and the second active material layer 23 is provided on the second tab 20, which completely covers the surface of the second current collector 21. The second active material layer 23 can be a conventional solid-state electrolyte layer.

[0064] The second tab 20, the first tab 10, the second tab 20, the first tab 10,..., the second tab 20 are stacked and fixed in sequence. The stacked positive and negative tabs are aligned in the length and width directions to prevent the tabs from shifting and misaligning during the turnover process. The stacked core package undergoes existing processes such as welding, packaging, liquid injection, formation, Degas, capacity distribution, sorting, etc. to complete the battery production. Among them, the semi-solid-state battery needs to be injected with liquid, and the all-solid-state battery does not need to add liquid electrolyte.

[0065] Embodiment two

[0066] Figures 10 to 13Embodiment two is shown, wherein the same or corresponding parts as embodiment one adopt the corresponding reference numerals of embodiment one. For the sake of simplicity, only the difference between embodiment two and embodiment one is described. The difference is that the second tab 20 is provided with an insulation layer 30. The second current collector 21 is formed with a second material area 211 and a second empty foil area 212, the second empty foil area 212 is annularly arranged on the second material area 211, and at least one side of the second empty foil area 212 away from the second material area 211 is provided with a second lug 22, the second empty foil area 212 is provided with the insulation layer 30, the surrounding part 31 wraps the edge of the second current collector 21, and the avoiding part 32 accommodates the second lug 22.

[0067] By providing the insulation layer 30 on the second empty foil area 212, the burr at the edge of the second current collector 21 is wrapped by the surrounding part 31, and the avoiding part 32 provides an avoiding space for the second lug 22 to avoid interference between the insulation layer 30 and the second lug 22. As shown in Figure 10 and Figure 11 , the second tab 20 has a single-sided lug, and the avoiding part 32 is located at the position of the second empty foil area 212 opposite to the second lug 22. The avoiding part 32 can be a notch provided on the insulation layer 30 to provide an avoiding space for the second lug 22.

[0068] Since the first tab 10 is provided with the insulation layer 30 in embodiment one, in the present embodiment, the first tab 10 and the second tab 20 are both provided with the insulation layer 30. In the present embodiment, the first tab 10 is a positive tab, and the second tab 20 is a negative tab.

[0069] In the direction perpendicular to the surface of the second current collector 21, the cross-sectional shape of the insulation layer 30 is U-shaped. This achieves full wrapping and avoids burrs from being exposed.

[0070] The width of the second empty foil area 212 is 0.5-1.5mm. As shown in Figure 10 , D4 represents the width of the second empty foil area 212, and D4 is 0.5-1.5mm, for example, 0.5mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm or 1.5mm. The effect of limiting the width range of the second empty foil area 212 can be referred to the effect of limiting the width range of the first empty foil area 112, which will not be described here.

[0071] The second material area 211 is provided with a second active material layer 23. The second active material layer 23 can adopt an existing coating layer, or the second active material layer 23 adopts an existing solid electrolyte layer, or the second active material layer 23 includes a coating layer and a solid electrolyte layer provided on the coating layer.

[0072] The inner side edge of the insulation layer 30 abuts against the second active material layer 23, so that the insulation layer 30 and the second active material layer 23 neither overlap nor have a gap, ensuring the flatness of the second tab 20. The thickness of the insulation layer 30 is less than or equal to the thickness of the second active material layer 23, so that the edge thickness of the second tab 20 is equal to or close to the main body thickness of the second tab 20, ensuring the flatness of the second tab 20.

[0073] The insulation tape 40 is arranged on both sides of the second foil-free area 212 in the thickness direction of the second tab 22, covers the avoiding part 32 and part of the second tab 22, and the two ends of the insulation tape 40 are overlapped with the surrounding part 31. By arranging the insulation tape 40, the position where the insulation layer 30 is disconnected can be connected, and the insulation tape 40 covers the joint area of the second tab 22 and the second current collector 21, so that the second current collector 21 is completely covered.

[0074] In the direction away from the second material area 211, the size of the insulation tape 40 covering the second tab 22 is 0.5-2mm. Referring to Figure 13 D5 represents the size of the insulation tape 40 covering the second tab 22 in the direction away from the second material area 211, and D5 is valued between 0.5-2mm, for example, 0.5mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.8mm or 2mm. The effect of limiting the covering size of the insulation tape 40 on the second tab 22 can be referred to the effect of limiting the covering size of the insulation tape 40 on the first tab 12, which will not be repeated here.

[0075] The two ends of the insulation tape 40 are overlapped with the surrounding part 31, so that the avoiding part 32 is completely covered and the joint area of the second tab 22 and the second current collector 21 is completely covered. The distance between each end of the insulation tape 40 and the surrounding part 31 can be equal or not equal. Referring to Figure 13 D6 represents the distance between each end of the insulation tape 40 and the surrounding part 31, and D3 is valued between 0.5-2mm, for example, 0.5mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.8mm or 2mm. The effect of limiting the overlapping size of the insulation tape 40 and the surrounding part 31 has been described before, which will not be repeated here.

[0076] The thickness of the insulation tape 40 is less than or equal to the thickness of the second active material layer 23, ensuring the flatness of the second tab 20. The insulation tape 40 can adopt one of the electrolyte-resistant PET adhesive paper, PP adhesive paper, PC adhesive paper and PVC adhesive paper, which has excellent tensile strength and adhesive strength, and also has good electrolyte resistance.

[0077] The second pole piece 20, the first pole piece 10, the second pole piece 20, the first pole piece 10,..., and the second pole piece 20 are stacked in sequence, and the stacked positive and negative pole pieces are aligned in the length and width directions, so that the pole pieces can be prevented from being offset and misaligned during the turnover process. After the stacked core package is subjected to existing processes such as welding, packaging, liquid injection, formation, degassing, capacity distribution, sorting, and the like, the battery production is completed. Among them, the semi-solid-state battery needs to be injected with liquid, and the all-solid-state battery does not need to add liquid electrolyte.

[0078] The above embodiments only illustrate the basic principles and characteristics of the present application, and the present application is not limited by the above embodiments. Without departing from the spirit and scope of the present application, various changes and modifications can be made to the present application, and these changes and modifications all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A stacked battery, characterized by, The first pole piece (10) and the second pole piece (20) are alternately and laminatedly arranged; The first pole piece (10) comprises a first current collector (11), a first material area (111) and a first empty foil area (112) are formed on the first current collector (11), the first empty foil area (112) is annularly arranged on the first material area (111), and a first tab (12) is arranged on at least one side of the first empty foil area (112) away from the first material area (111); The laminated battery further comprises an insulation layer (30), the insulation layer (30) is arranged on the first empty foil area (112), and the insulation layer (30) comprises a surrounding part (31) and a avoiding part (32), the surrounding part (31) wraps the edge of the first current collector (11), and the avoiding part (32) accommodates the first tab (12); The second pole piece (20) comprises a second current collector (21) and a second tab (22), and the edge of the second current collector (21) is accommodated in the area where the insulation layer (30) is located.

2. The stacked battery of claim 1, wherein The cross-sectional shape of the insulation layer (30) is U-shaped along the surface direction perpendicular to the first current collector (11).

3. The stacked battery of claim 2, wherein, The first material area (111) is provided with a first active material layer (13), and the inner side edge of the insulation layer (30) abuts against the first active material layer (13).

4. The stacked battery of claim 1, wherein The width of the first empty foil area (112) is 0.5-1.5mm.

5. The stacked battery of claim 1, wherein, The first material area (111) is provided with a first active material layer (13), and the thickness of the insulation layer (30) is less than or equal to the thickness of the first active material layer (13).

6. The stacked battery of claim 1, wherein, Insulation tapes (40) are arranged on both sides of the first empty foil area (112) in the thickness direction of the first tab (12), the insulation tapes (40) cover the avoiding part (32) and part of the first tab (12), and the two ends of the insulation tapes (40) are overlapped with the surrounding part (31).

7. The stacked battery of claim 6, wherein, Along the direction away from the first material area (111), the size of the insulation tape (40) covering the first tab (12) is 0.5-2mm; and / or, the distance between each end of the insulation tape (40) and the surrounding part (31) is 0.5-2mm.

8. The stacked battery of claim 1, wherein, The length of the first current collector (11) is equal to the length of the second current collector (21), and the width of the first current collector (11) is equal to the width of the second current collector (21).

9. The stacked battery of claim 1, wherein, The second current collector (21) is provided with a second material area (211) and a second empty foil area (212), the second empty foil area (212) is annularly arranged on the second material area (211), the second tab (22) is arranged on at least one side of the second empty foil area (212) away from the second material area (211), the second empty foil area (212) is provided with the insulation layer (30), the surrounding part (31) wraps the edge of the second current collector (21), and the avoiding part (32) accommodates the second tab (22).

10. The stacked battery of any one of claims 1-9, wherein, The first pole piece (10) is a positive pole piece, and the second pole piece (20) is a negative pole piece; or the first pole piece (10) is a negative pole piece, and the second pole piece (20) is a positive pole piece.

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