Batteries and battery packs

Abstract

The present invention relates to the technical field of battery devices and discloses a battery and a battery pack. The battery comprises: at least two battery cells stacked along the X-direction; the battery cells comprise: a separator layer and an outer film layer, wherein the outer film layers located on two adjacent surfaces do not overlap on a first projection plane along the X-direction; the first projection plane has an area T; and the outer film layers located on the two adjacent surfaces have an area S outside their projections on the first projection plane, satisfying the following: 0.02 ≤ S / T ≤ 6.2. The battery provided by the present invention prevents compression of the outer film layers, thereby preventing lithium deposition.

Description

Technical Field

[0001] The present invention relates to the technical field of battery devices, and in particular to a battery and a battery pack. Background Art

[0002] The outer surface of the battery cell is covered with an insulating film, which not only secures the end of the separator to prevent warping but also improves the insulation performance of the battery cell. When two battery cells are placed opposite each other to form a battery, the insulating films of the two cells may overlap. As the battery cells expand during charging and discharging, the overlapping insulating films squeeze each other, causing indentations in the separator and leading to problems such as lithium deposition. Summary of the Invention

[0003] In view of this, the present invention provides a battery and a battery pack to solve the problem that overlapping positions of insulating films easily cause indentations on the diaphragm, resulting in lithium deposition.

[0004] In a first aspect, the present invention provides a battery comprising:

[0005] At least two battery cells stacked along the X direction;

[0006] The battery cell includes: a positive electrode sheet and a negative electrode sheet; a separator film layer located between the positive electrode sheet and the negative electrode sheet, and the separator film layer is at least partially located on the outer surface of the battery cell; an outer film layer, the outer film layer is at least partially arranged on the outer surface of the separator film layer forming the outer surface of the battery cell;

[0007] The battery cell is defined as having a straight section, and the surfaces where the straight sections of two adjacent battery cells are arranged opposite to each other are adjacent surfaces, and the adjacent surfaces are perpendicular to the X direction;

[0008] The area where the positive electrode sheet overlaps with the adjacent surface projection along the X direction is defined as the first projection surface;

[0009] The adjacent surfaces of two adjacent battery cells are respectively provided with outer coating layers, and the projections of the outer coating layers respectively located on the two adjacent surfaces along the X direction on the first projection plane do not overlap;

[0010] The area of ​​the first projection surface is T; the area outside the projection of the outer coating layer located on the two adjacent surfaces on the first projection surface is S, satisfying: 0.02≤S / T≤6.2.

[0011] Beneficial effect: By making the projections of the outer film layers 4 located on the two adjacent surfaces along the X direction on the first projection plane not overlap, the outer film layers of the two adjacent battery cells are prevented from overlapping after being fitted and assembled. As the battery cells expand during charging and discharging, the overlapping positions of the outer film layers are prevented from being squeezed against each other, thereby avoiding indentation on the separator film layer and preventing problems such as lithium plating.

[0012] By defining the lower limit of S / T, a certain blank area is ensured between the projections of the two outer film layers on the first projection surface. This prevents the adjacent surfaces from being completely covered by the outer film layers, increases the wettability of the battery cell after injection, facilitates the soaking of the battery cell, and ensures the charge and discharge performance during subsequent use. Furthermore, by defining the upper limit of S / T, the area outside the projections of the two outer film layers on the first projection surface is prevented from being too large, which would result in excessive exposure of the separator layer. This reduces the risk of the separator layer being punctured by foreign objects and prevents the positive and negative short circuits caused by separator layer rupture, thereby improving the safety performance of the battery cell.

[0013] In a second aspect, the present invention further provides a battery pack, comprising: the battery as described above.

[0014] Since the battery pack includes batteries and has the same effects as the batteries, it will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 Schematic diagram of the decomposed state of the battery of the present invention;

[0017] Figure 2 Schematic diagram of the bonding state of the first battery cell and the second battery cell of the present invention;

[0018] Figure 3 Schematic diagram of the first battery cell and the second battery cell in a separated state according to the present invention;

[0019] Figure 4 Schematic diagram of the cross-sectional state of the first and second battery cells of the present invention Figure 1 ;

[0020] Figure 5 Schematic diagram of the cross-sectional state of the first and second battery cells of the present invention Figure 2 ;

[0021] Figure 6 A schematic cross-sectional view of a first type of battery cell according to the present invention;

[0022] Figure 7 A schematic cross-sectional view of a second type of battery cell according to the present invention;

[0023] Description of reference numerals:

[0024] 1. Housing; 2. Cell; 21. First cell; 22. Second cell; 23. Tab; 201. Straight section; 202. Arc-shaped corner;

[0025] 3. Cover plate; 31. Pole; 4. Outer coating layer;

[0026] 5. Pole sheet; 51. Positive electrode sheet; 52. Negative electrode sheet; 6. Separator membrane layer; 61. Finishing part. DETAILED DESCRIPTION

[0027] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0030] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] The following combination Figures 1 to 7 , describing embodiments of the present invention.

[0032] In order to facilitate a clearer understanding of the positional relationship of the embodiment of the present invention, the coordinate directions of the embodiment of the present invention are defined below in combination with the coordinate axes shown in the accompanying drawings: the X direction is the stacking direction of the battery cell 2, and the adjacent surface is perpendicular to the X direction; the plane parallel to the X direction and perpendicular to the adjacent surface is defined as the positioning surface, the Y direction is parallel to the adjacent surface and the positioning surface at the same time; the Z direction is parallel to the adjacent surface and perpendicular to the positioning surface.

[0033] According to an embodiment of the present invention, on one hand, a battery is provided, comprising:

[0034] At least two battery cells 2 stacked along the X direction;

[0035] The battery cell 2 includes: a positive electrode sheet 51 and a negative electrode sheet 52; a separator layer 6, located between the positive electrode sheet 51 and the negative electrode sheet 52, and the separator layer 6 is at least partially located on the outer surface of the battery cell 2; an outer film layer 4, the outer film layer 4 is at least partially disposed on the outer surface of the separator layer 6 forming the outer surface of the battery cell;

[0036] The battery cell 2 is defined as having a straight section 201 , and the surfaces of the straight sections 201 of two adjacent battery cells 2 facing each other are called adjacent surfaces, and the adjacent surfaces are perpendicular to the X direction;

[0037] The area where the positive electrode sheet 51 overlaps with the adjacent surface projection along the X direction is defined as the first projection surface;

[0038] The adjacent surfaces of two adjacent battery cells 2 are respectively provided with outer coating layers 4, and the projections of the outer coating layers 4 respectively located on the two adjacent surfaces along the X direction on the first projection plane do not overlap;

[0039] The area of ​​the first projection surface is T; the area outside the projection of the outer coating layer 4 on the two adjacent surfaces on the first projection surface is S, which satisfies the following: 0.02≤S / T≤6.2.

[0040] The battery includes a housing 1 having an opening formed therein, and the battery cell 2 is adapted to be loaded into the housing 1 through the opening. In this embodiment, the opening of the housing 1 is formed at one end of the housing 1 along the Z direction, that is, the battery cell 2 is adapted to be loaded into the housing 1 through the opening along the Z direction.

[0041] The cover plate 3 is disposed on the opening of the housing 1 . A pole 31 is disposed on the cover plate 3 . A pole lug 23 is disposed on the end of the battery cell 2 facing the cover plate 3 along the Z direction.

[0042] The battery cell 2 is formed by stacking or winding a positive electrode sheet 51 , a negative electrode sheet 52 and a separator layer 6 .

[0043] As one of the implementation forms, combined with Figure 6As shown, the battery cell is composed of a positive electrode sheet 51, a negative electrode sheet 52, and a separator film layer 6 stacked in sequence, with the positive electrode sheets 51 and the negative electrode sheets 52 arranged alternately. That is, the electrode sheets adjacent to the positive electrode sheet 51 on both sides along the X direction are both negative electrode sheets 52, and the electrode sheets adjacent to the negative electrode sheet 52 on both sides along the X direction are both positive electrode sheets 51. A separator film layer 6 is provided between every two adjacent electrode sheets 5. The separator film layer 6 can be a continuous film structure or a discontinuous film structure provided layer by layer.

[0044] As another implementation, combining Figure 7 As shown, the battery cell is formed by winding a positive electrode sheet 51, a negative electrode sheet 52, and a separator film layer 6. The separator film layer 6 is continuously wound with one of the positive electrode sheet 51 and the negative electrode sheet 52 as the winding center. After the winding is completed, the positive electrode sheets 51 and the negative electrode sheets 52 are arranged in a staggered manner. That is, the electrode sheets adjacent to each other on both sides of the positive electrode sheet 51 along the stacking direction are both negative electrode sheets 52, and the electrode sheets adjacent to each other on both sides of the negative electrode sheet 52 along the stacking direction are both positive electrode sheets 51. A separator film layer 6 is provided between every two adjacent electrode sheets 5.

[0045] After a predetermined number of positive electrode sheets 51 and negative electrode sheets 52 are stacked, the shape of the battery cell 2 is basically formed. At this time, the separator film layer 6 is continued to be wound around the battery cell 2 for more than one circle, so that the separator film layer 6 can at least partially cover the outer surface of the battery cell, thereby preventing the positive electrode sheet 51 or the negative electrode sheet 52 from being directly exposed on the outermost layer of the battery cell 2, so that the separator film layer 6 plays an insulating and protective role.

[0046] At the end of the winding of the separator film layer 6, the separator film layer 6 forms a tail portion 61 on the outer surface of the battery cell. Since the separator film layer 6 generally does not have adhesive properties, the tail portion 61 cannot be completely adhered and fixed to the battery cell 2. By further wrapping the outer film layer 4 on the outside of the separator film layer 6, one end of the outer film layer 4 is fixed to the outside of the tail portion 61, and the outer film layer 4 is further wrapped on the outer surface of the battery cell, so that the outer film layer 4 is at least partially covered on the outside of the separator film layer 6 forming the outer surface of the battery cell. On the one hand, it can achieve the fixation of the tail portion 61 of the separator film layer 6, and on the other hand, it can further improve the insulation performance of the outermost layer of the battery cell 2, thereby protecting the separator film layer 6 and the electrode inside the battery cell 2.

[0047] In this embodiment, the X direction is the stacking direction of the battery cells 2, and the axis direction of the winding of the separator film layer 6 is parallel to the Z direction. The Y direction is perpendicular to both the X and Z directions.

[0048] The battery cell 2 is defined as having a straight section 201, and the surfaces of the straight sections 201 of two adjacent battery cells 2 facing each other are adjacent surfaces, and the adjacent surfaces are perpendicular to the X direction; Figures 1 to 4As shown, taking the battery including the first battery cell 21 and the second battery cell 22 stacked along the X direction as an example, the surfaces where the first battery cell 21 and the second battery cell 22 are in contact are defined as the first adjacent surface and the second adjacent surface respectively.

[0049] The area where the positive electrode sheet 51 overlaps with the adjacent surface projection along the X direction is defined as the first projection surface.

[0050] Combine Figure 4 As shown, the outer film layer 4 is arranged around the first battery cell 21 or the second battery cell 22 with the Z direction as the axis. At least one end of the outer film layer 4 of the first battery cell 21 is located at the first adjacent surface, and at least one end of the outer film layer 4 of the second battery cell 22 is located at the second adjacent surface. Figure 4 As shown, by making the projections of the outer coating layer 4 of the first battery cell 21 located on the first adjacent surface and the outer coating layer 4 of the second battery cell 22 located on the second adjacent surface along the X direction on the first projection surface not overlap, after the first battery cell 21 and the second battery cell 22 are fitted and assembled, the outer coating layers 4 of the two battery cells are prevented from overlapping, and as the battery cells expand during charging and discharging, the overlapping positions of the outer coating layers 4 are prevented from being squeezed against each other, thereby avoiding indentation on the separator film layer 6 and preventing problems such as lithium plating.

[0051] In this embodiment, the battery cell 2 is defined as having a straight section 201. For a laminated battery, the area between the two ends along the length of the battery cell is the straight section 201; while for a wound battery, the straight section 201 is the area without the outer curved R corner 202.

[0052] The area of ​​the first projection surface is T; the area outside the projection of the outer film layers 4 on the two adjacent surfaces on the first projection surface is S. By defining the lower limit of S / T, a certain blank area is ensured between the projections of the two outer film layers 4 on the first projection surface, thereby preventing the adjacent surfaces from being completely covered by the outer film layers 4. This increases the wettability of the battery cell after injection, facilitates the wettability of the battery cell, and ensures the charge and discharge performance during subsequent use. By also defining the upper limit of S / T, the area outside the projection of the two outer film layers 4 on the first projection surface is prevented from being too large, thereby exposing too much of the separator film layer 6. This avoids the risk of the separator film layer 6 being punctured by foreign objects, prevents the positive and negative short circuit caused by the rupture of the separator film layer 6, and improves the safety performance of the battery cell.

[0053] In this embodiment, two adjacent battery cells 2 are respectively located on the outer coating layer 4 of the adjacent surface, and there are two situations in the non-overlapping area after projection on the first projection plane along the X direction: ① The outer coating layer 4 is not attached to the edge of the straight section 201 along the Y direction, so that the projections of the edge area and the middle area of ​​the straight section 201 along the Y direction do not overlap; ② The outer coating layer 4 covers the edge of the straight section 201 along the Y direction, so that only the projection of the middle area of ​​the straight section 201 does not overlap.

[0054] Among them, situation ① further includes that the projections of the edge areas on both sides of the straight section 201 along the Y direction do not overlap, and the projections of the edge areas on one side of the straight section 201 along the Y direction do not overlap. Figure 4 、 Figure 5 Describe in detail.

[0055] Illustratively, in this embodiment, the value of S / T may be 0.02 or 0.08 or 0.12 or 0.32 or 0.97 or 1.4 or 2.36 or 3.2 or 4.5 or 5.1 or 6 or 6.2, etc., or may be an interval formed by any two of the above values.

[0056] In some embodiments, the value of S satisfies: 800 mm 2 ≤S≤72000mm 2 .

[0057] For example, in this embodiment, the value of S can be 800 mm 2 or 1000mm 2 or 1500mm 2 or 3000mm 2 or 7000mm 2 or 10000mm 2 or 15000mm 2 or 30000mm 2 or 42000mm 2 or 53000mm 2 or 61000mm 2 or 72000mm 2 etc., or it can be an interval range formed by any two of the above values.

[0058] In some embodiments, the value of T satisfies: 11200 mm 2 ≤T≤75000mm 2 .

[0059] For example, in this embodiment, the value of T can be 11200 mm 2 or 12200mm 2 or 15000mm 2 or 30000mm 2 or 42000mm 2 or 53000mm 2 or 61000mm 2 or 72000mm 2 or 75000mm 2 etc., or it can be an interval range formed by any two of the above values.

[0060] In some embodiments, the non-overlapping area of ​​the outer coating layer 4 on the two adjacent surfaces along the X direction and the projection of the first projection plane includes a first non-overlapping area, which satisfies: 0.02≤S1 / T≤4.8, where S1 is the area when the first non-overlapping area is at the middle position of the straight section 201.

[0061] For example, in this embodiment, the value of S1 / T may be 0.02 or 0.08 or 0.12 or 0.32 or 0.97 or 1.4 or 2.36 or 3.2 or 4.5 or 4.8, etc., or may be an interval formed by any two of the above values.

[0062] In this embodiment, the outer film layer 4 covers the edge of the straight section 201 along the Y direction, so that only the projection of the middle area of ​​the straight section 201 does not overlap. In order to meet the wetting requirements and ensure the wetting ability after the battery cell is filled with liquid, the area of ​​the middle area needs to be set larger, or the length of the middle area can be set longer.

[0063] In some embodiments, the value of S1 satisfies: 800 mm 2 ≤S1≤57000mm 2 .

[0064] For example, in this embodiment, the value of S can be 800 mm 2 or 1000mm 2 or 1500mm 2 or 3000mm 2 or 7000mm 2 or 10000mm 2 or 15000mm 2 or 30000mm 2 or 42000mm 2 or 53000mm 2 or 57000mm 2 etc., or it can be an interval range formed by any two of the above values.

[0065] In some embodiments, the tail end of at least one outer film layer 4 extends beyond the straight section 201 of the battery cell 2 .

[0066] During battery charging and discharging, the battery's large surface expands significantly. Therefore, covering the large surface with more outer film layers 4 helps prevent the separator layer 6 from being punctured by foreign objects. In this embodiment, by extending the tail end of at least one outer film layer 4 beyond the straight section 201 of the battery cell 2, the outer film layer 4 covers the outer surface of the battery cell 2, thereby increasing the area covered by the outer film layer 4. This prevents the separator layer 6 from rupturing and causing a short circuit between the positive and negative electrodes, thereby improving the safety performance of the battery cell.

[0067] In this embodiment, the following condition is satisfied: 0.03 ≤ S1 / T ≤ 4.65. Because the tail end of at least one outer film layer 4 extends beyond the straight section 201 of the cell 2, that is, the tail end of at least one outer film layer 4 extends to the area of ​​the curved R-shaped corner 202, the area wetted by the separator film layer 6 is reduced. Therefore, S1 needs to be increased to ensure sufficient wetted area in the cell after injection to meet the wettability requirements.

[0068] For example, in this embodiment, the value of S1 / T may be 0.03 or 0.08 or 0.12 or 0.32 or 0.97 or 1.4 or 2.36 or 3.2 or 4.5 or 4.65, etc., or may be an interval formed by any two of the above values.

[0069] In some embodiments, the tail end of at least one outer film layer 4 extends to the arc-shaped R corner portion 202 of the battery cell 2 .

[0070] By setting the tail end of at least one outer film layer 4 to extend to the arc-shaped R corner 202 of the battery cell 2, the area of ​​the outer film layer 4 covering the outer surface of the battery cell 2 is increased. At this time, although the area of ​​the separator film layer 6 being infiltrated is reduced, the outer film layer 4 wraps the separator film layer 6 in the area of ​​the arc-shaped R corner 202, thereby enhancing the ability to resist foreign matter, reducing the occurrence of positive and negative short circuits caused by rupture of the separator film layer 6, and improving the safety performance of the battery cell.

[0071] In this embodiment, the following condition is satisfied: 0.16 ≤ S1 / T ≤ 4.65. Because the tail end of at least one outer film layer 4 extends to the curved R-shaped corner 202 of the cell 2, the outer film layer 4 wraps around the separator film layer 6 in the area of ​​the curved R-shaped corner 202, reducing the area wetted by the separator film layer 6. Therefore, S1 needs to be increased to ensure sufficient wetted area in the cell after liquid injection to meet the wetted area requirement.

[0072] For example, in this embodiment, the value of S1 / T may be 0.16 or 0.32 or 0.97 or 1.4 or 2.36 or 3.2 or 4.5 or 4.65, etc., or may be an interval formed by any two of the above values.

[0073] In some embodiments, the battery cell 2 is a wound battery cell, and the tail end of the outer film layer 4 extends to the arc-shaped R corner 202 of the battery cell 2 .

[0074] When the battery cell 2 is a wound battery cell, the tail end of the outer film layer 4 is extended to the arc-shaped R corner 202 of the battery cell 2, thereby increasing the area of ​​the outer film layer 4 covering the outer surface of the battery cell 2. At this time, although the area of ​​the separator film layer 6 being infiltrated is reduced, the outer film layer 4 wraps the separator film layer 6 in the arc-shaped R corner 202 area, thereby enhancing the ability to resist foreign matter, reducing the occurrence of positive and negative short circuits caused by rupture of the separator film layer 6, and improving the safety performance of the battery cell.

[0075] In some embodiments, the trailing end of at least one outer covering layer 4 extends to the opposite side of the adjacent surface.

[0076] By extending the tail end of at least one outer film layer 4 to the opposite side of the adjacent surface, the area wetted by the separator film layer 6 is further reduced. In this case, S1 must be further increased to ensure sufficient wetted area in the cell after injection to meet the wettability requirements. Therefore, the lower limit of the S1 / T ratio needs to be higher than the lower limit of the S / T ratio. However, by increasing the area of ​​the outer film layer 4 covering the outer surface of the cell 2 and increasing the area of ​​the outer film layer 4 covering the large surface of the battery, the probability of large surfaces being invaded by foreign matter is reduced, thereby enhancing foreign matter resistance, reducing the possibility of positive and negative short circuits caused by rupture of the separator film layer 6, and improving the safety performance of the battery cell.

[0077] In this embodiment, the following condition is satisfied: 2.0 ≤ S1 / T ≤ 4.8. Because the tail end of at least one outer film layer 4 extends to the opposite side of the adjacent surface, the area wetted by the separator film layer 6 is reduced. Therefore, S1 needs to be further increased to ensure that the battery cell has sufficient wetted area after liquid injection to meet the wettability requirements.

[0078] For example, in this embodiment, the value of S1 / T may be 2.0, 2.36, 3.2, 4.5, 4.65, 4.8, etc., or may be an interval formed by any two of the above values.

[0079] In some embodiments, the tail end of the outer film layer 4 continues to extend beyond the opposite surface of the adjacent surface of the battery cell 2 .

[0080] By setting the tail end of the outer film layer 4 to continue to extend beyond the opposite surface of the adjacent surface of the battery cell 2, that is, the outer film layer 4 completely covers the opposite surface of the adjacent surface, the area of ​​the outer film layer 4 covering the large surface of the battery is increased, and the probability of the large surface being invaded by foreign matter is reduced, thereby enhancing the ability to resist foreign matter, reducing the occurrence of positive and negative short circuits caused by rupture of the separator film layer 6, and improving the safety performance of the battery cell.

[0081] In this embodiment, the following is satisfied: 2.1 ≤ S1 / T ≤ 4.8. Because the tail end of the outer film layer 4 continues to extend beyond the surface opposite the adjacent surface of the battery cell 2, the area wetted by the separator film layer 6 is further reduced. Therefore, S1 needs to be further increased to ensure that the battery cell has sufficient wetted area after liquid injection to meet the wettability requirements.

[0082] For example, in this embodiment, the value of S1 / T may be 2.1 or 2.36 or 3.2 or 4.5 or 4.65 or 4.8, etc., or may be an interval formed by any two of the above values.

[0083] In some embodiments, the battery cell 2 is a wound battery cell, and the tail end of the outer film layer 4 continues to extend to the arc-shaped R corner portion 202 on the other side of the battery cell 2 .

[0084] The battery cell 2 is a wound battery cell. The tail end of the outer film layer 4 is extended beyond the opposite surface of the adjacent surface of the battery cell 2, and the tail end of the outer film layer 4 continues to extend to the arc-shaped R corner 202 on the other side of the battery cell 2. That is, the outer film layer 4 completely covers the opposite surface of the adjacent surface, and to a certain extent covers the arc-shaped R corner 202 on the other side of the battery cell 2, thereby increasing the area of ​​the large surface of the battery covered by the outer film layer 4, reducing the probability of the large surface being invaded by foreign matter, and protecting the arc-shaped R corner 202 on the other side of the battery cell 2, thereby enhancing the ability to resist foreign matter, reducing the occurrence of positive and negative pole short circuits caused by rupture of the separator film layer 6, and improving the safety performance of the battery cell.

[0085] In this embodiment, the following condition is satisfied: 3.1 ≤ S1 / T ≤ 4.8. Because the tail end of the outer film layer 4 extends beyond the surface opposite the adjacent surface of the battery cell 2 and continues to extend to the curved R-shaped corner portion 202 on the other side of the battery cell 2, the area wetted by the separator film layer 6 is further reduced. Therefore, S1 needs to be further increased to ensure that the battery cell has sufficient wetted area after liquid injection to meet the wetted area requirement.

[0086] For example, in this embodiment, the value of S1 / T may be 3.1, 3.2, 4.5, 4.65, 4.8, etc., or may be an interval formed by any two of the above values.

[0087] In some embodiments, the non-overlapping areas of the outer coating layer 4 respectively located on the two adjacent surfaces along the X-direction with the projection of the first projection plane include a first non-overlapping area and a second non-overlapping area, wherein the first non-overlapping area is located in the middle of the straight section 201, and the second non-overlapping area is located on one side of the straight section 201.

[0088] In this embodiment, the edge of one side of the straight section 201 is not covered by the outer film layer 4, so that the edge of the straight section 201 can also be infiltrated by the electrolyte, and the battery cell is more easily infiltrated by the electrolyte.

[0089] In this embodiment, the following condition is satisfied: 0.03≤(S1+S2) / T≤4.8, where S1 is the area of ​​the first non-overlapping region; and S2 is the area of ​​the second non-overlapping region.

[0090] S1 is the area of ​​the first non-overlapping area, S2 is the area of ​​the second non-overlapping area, that is, S1 is the area of ​​the middle non-overlapping area, and S2 is the area of ​​the edge non-overlapping area. Since the edge of one side of the straight section 201 can be wetted, the wetting requirements can be met after the area of ​​the middle area is appropriately reduced.

[0091] Illustratively, in this embodiment, the value of (S1+S2) / T may be 0.03 or 0.06 or 0.1 or 0.8 or 1.1 or 2.1 or 3.1 or 3.2 or 4.5 or 4.65 or 4.8, etc., or may be an interval formed by any two of the above values.

[0092] In some embodiments, the value of S2 satisfies: 800 mm 2 ≤S2≤54000mm 2 .

[0093] For example, in this embodiment, the value of S2 can be 800 mm 2 or 1000mm 2 or 1500mm 2 or 3000mm 2 or 7000mm 2 or 10000mm 2 or 15000mm 2 or 30000mm 2 or 42000mm 2 or 53000mm 2 or 54000mm 2 etc., or it can be an interval range formed by any two of the above values.

[0094] In this embodiment, the following condition is satisfied: 0.01≤S1 / S2≤71.

[0095] Since S2 is located at the edge of the straight section 201 , the edge is better wetted than the middle section of the cell. Therefore, in order to ensure better wetting of the middle position of the straight section 201 , the area of ​​S1 needs to be appropriately increased.

[0096] Illustratively, in this embodiment, the value of S1 / S2 can be 0.01 or 0.06 or 0.1 or 0.8 or 1.1 or 2.1 or 3.1 or 3.2 or 4.5 or 4.65 or 4.8 or 10 or 28 or 48 or 56 or 65 or 71, etc., or it can be an interval range formed by any two of the above values.

[0097] In some embodiments, the non-overlapping areas of the outer coating layer 4 located on the two adjacent surfaces along the X-direction with the projection of the first projection plane include a first non-overlapping area, a second non-overlapping area, and a third non-overlapping area, wherein the first non-overlapping area is located in the middle of the straight section 201, and the second non-overlapping area and the third non-overlapping area are respectively located on both sides of the straight section 201.

[0098] In this embodiment, the edges on both sides of the straight section 201 are not covered by the outer film layer 4, so that the edges on both sides of the straight section 201 can also be infiltrated by the electrolyte, and the battery cell is more easily infiltrated by the electrolyte.

[0099] In this embodiment, the following condition is satisfied: 0.03≤(S1+S2+S3) / T≤4.8, where S1 is the area of ​​the first non-overlapping region; S2 is the area of ​​the second non-overlapping region; and S3 is the area of ​​the third non-overlapping region.

[0100] Since the edges on both sides of the straight section 201 can be wetted, the area S1 of the outer coating layer 4 in the middle of the straight section 201 where the projection along the X direction does not overlap with the projection of the first projection plane can be appropriately reduced, and even after the reduction, the wettability requirement can be met.

[0101] In this embodiment, the following is satisfied: 0.03≤(S2+S3) / S1≤67.5.

[0102] Since the overall value of the area T of the first projection surface is fixed, when the area S2+S3 is too large, the area S1 will be reduced, affecting the infiltration of the middle area. Therefore, it is necessary to reasonably control the ratio of (S2+S3) / S1.

[0103] In some embodiments, the value of S3 satisfies: 800 mm 2 ≤S3≤54000mm 2 .

[0104] For example, in this embodiment, the value of S3 can be 800 mm 2 or 1000mm 2 or 1500mm 2 or 3000mm 2 or 7000mm 2 or 10000mm 2 or 15000mm 2 or 30000mm 2 or 42000mm 2 or 53000mm 2 or 54000mm 2 etc., or it can be an interval range formed by any two of the above values.

[0105] In some embodiments, the thicknesses of the outer film layers 4 of two adjacent battery cells 2 are Q1 and Q2 respectively, satisfying the following: 0.8≤Q1 / Q2≤1.2.

[0106] By limiting the ratio Q1 / Q2 of the thickness of the outer film layer 4 of two adjacent battery cells 2 to be between 0.8 and 1.2, it is possible to ensure that the wetting degree of the two adjacent battery cells 2 is equivalent, and at the same time, after assembly, the thickness of the adjacent assembly plane is ensured to be uniform.

[0107] In some embodiments, the sum of the thicknesses of the outer film layers 4 of two adjacent battery cells 2 is Q1+Q2, and the thickness of a single battery cell 2 along the X direction is D, satisfying: 1.2≥Q1 / Q2≥1, 20mm≤D≤40mm.

[0108] When the outer film layer 4 is too thick, it will occupy the entire thickness of the battery cell and affect the battery space utilization. Therefore, it is necessary to reasonably control the sum Q1+Q2 of the thickness of the outer film layer 4 of two adjacent battery cells 2 and the thickness D of the battery cell 2 along the X direction.

[0109] Illustratively, in this embodiment, the value of Q1 / Q2 may be 1 or 1.11 or 1.15 or 1.18 or 1.2, etc., or may be an interval formed by any two of the above values.

[0110] For example, in this embodiment, the value of D may be 20 mm, 25 mm, 28 mm, 31 mm, 35 mm, 37 mm, or 40 mm, etc., or may be an interval formed by any two of the above values.

[0111] In some embodiments, the thickness of the outer film layer 4 of the battery cell 2 is Q; the outer film layer 4 on the two adjacent surfaces, respectively, does not overlap with the projection of the first projection plane along the X direction, including a first non-overlapping area. The area of ​​the first non-overlapping area when it is the middle position of the straight section 201 is S1, which satisfies: 8.8×10 -8 ≤Q / S1≤2.5×10 -4 .

[0112] It should be noted that for two adjacent battery cells 2, the thickness of the outer film layer 4 of the two adjacent battery cells 2 is Q1 and Q2 respectively, and for one of the battery cells 2, the thickness of the outer film layer 4 arranged thereon is Q1 or Q2. In order to simplify the description, the thickness of the outer film layer 4 of the battery cell 2 is uniformly referred to as Q here.

[0113] When the thickness of the outer film layer 4 of the battery cell 2 is relatively thick, it is easy to affect the wetting of the battery cell. Therefore, the area of ​​S1 should be appropriately increased to ensure the wetting effect of the battery cell.

[0114] In some embodiments, along the height direction of the battery cell, the height of the positive electrode sheet 51 is less than that of the negative electrode sheet 52 , and the height of the negative electrode sheet 52 is less than that of the separator layer 6 ; the height of the outer film layer 4 is greater than that of the positive electrode sheet 51 .

[0115] By making the height of the positive electrode sheet 51 smaller than the height of the negative electrode sheet 52, the negative electrode sheet 52 can cover the positive electrode sheet 51, ensuring sufficient battery reaction; and by making the height of the negative electrode sheet 52 smaller than the height of the separator film layer 6, the separator film layer 6 can cover the negative electrode sheet 52, which can better protect the negative electrode sheet 52 and the positive electrode sheet 51 and improve the insulation performance.

[0116] In this embodiment, the height direction of the battery cell is the Z direction.

[0117] The height of the outer film layer 4 along the height direction of the battery cell is greater than the height of the positive electrode sheet 51 , and the outer film layer 4 can completely cover the positive electrode sheet 51 along the height direction of the battery cell.

[0118] In this embodiment, the minimum distance between the edge of the outer film layer 4 along the height direction of the battery cell and the positive electrode sheet 51 along the height direction of the battery cell is not less than 1 mm.

[0119] The edge of the outer film layer 4 along the height direction of the battery cell needs to be as far away from the positive electrode sheet 51 as possible to prevent the edge of the outer film layer 4 from squeezing the positive electrode sheet 51 after the battery cell expands when too close, causing the positive electrode sheet 51 to fall off.

[0120] In some embodiments, the minimum distance between the edge of the outer film layer 4 along the height direction of the battery cell and the edge of the separator film layer 6 along the height direction of the battery cell is in the range of 1 mm to 5 mm.

[0121] In this embodiment, the height direction of the battery cell is the Z direction.

[0122] In this embodiment, the height of the outer film layer 4 along the height direction of the battery cell can be less than the height of the separator film layer 6, that is, the edge of the outer film layer 4 along the height direction of the battery cell is located between the negative electrode 52 and the separator film layer 6, or the height of the outer film layer 4 along the height direction of the battery cell can be greater than the height of the separator film layer 6, that is, the edge of the outer film layer 4 along the height direction of the battery cell exceeds the edge of the separator film layer 6. At this time, the minimum distance between the edge of the outer film layer 4 along the height direction of the battery cell and the edge of the separator film layer 6 along the height direction of the battery cell should not be too large. When the outer film layer 4 exceeds the edge of the separator film layer 6, due to the lack of battery cell obstruction, if the edge is assembled with glue, it will stick to other battery components or foreign objects, thereby interfering with the smooth assembly and posing certain safety hazards.

[0123] In some embodiments, the tail portions 61 of two adjacent battery cells 2 are both located on opposite sides of the adjacent surfaces.

[0124] When the tail portions 61 are all located on the opposite side of the adjacent surface, the adjacent surface has an extra diaphragm than the opposite surface and is not easily wetted, but is safer.

[0125] In some embodiments, the tail portions 61 of two adjacent battery cells 2 are both located on adjacent surfaces.

[0126] When the tail portion 61 is located at the adjacent surface, the non-tail region of the adjacent surface is not covered with the diaphragm, so that the non-tail region of the adjacent surface has one less layer of diaphragm, thereby achieving better infiltration.

[0127] In some embodiments, combined Figure 2As shown, the thickness of a single battery cell 2 along the X direction is D, which satisfies: 0.0003≤D / S≤0.05.

[0128] As the thickness of the battery cell 2 increases, the electrolyte wettability requirements of the battery cell 2 increase. This embodiment associates the thickness D of a single battery cell 2 along the X-axis with its thickness S. By limiting the upper limit of the D / S ratio, this ensures that S increases as the thickness of the battery cell 2 increases, thereby improving the electrolyte wettability. At the same time, by limiting the lower limit of the D / S ratio, the occurrence of excessive S is avoided, preventing excessive exposure of the separator layer 6 and increasing the risk of the separator layer 6 being punctured by foreign objects.

[0129] In some embodiments, combined Figure 4 As shown, the thickness of the separation membrane layer 6 is F, which satisfies: F≥3 μm; at this time, the range of S / T satisfies: 0.05≤S / T≤6.2.

[0130] Since the thicker the thickness F of the separator layer 6 is, the higher the requirement for electrolyte wetting ability is, when the thickness F of the separator layer 6 satisfies: F≥3μm, the area S needs to be increased to improve the electrolyte wetting ability of the separator layer 6.

[0131] In some embodiments, the porosity of the separation membrane layer 6 is a, which satisfies: a≥20%; in this case, the range of S / T satisfies: 0.02≤S / T≤5.9.

[0132] Since the larger the porosity a of the separator membrane layer 6, the better its ability to infiltrate the electrolyte, when the porosity a of the separator membrane layer 6 satisfies: a≥20%, the area of ​​S can be appropriately reduced, that is, the upper limit of S is lowered, and the electrolyte infiltration requirements of the separator membrane layer 6 can still be met.

[0133] According to another aspect of an embodiment of the present invention, a battery pack is provided, comprising: the battery as described above.

[0134] The micro-short circuit test method used in this embodiment measures the resistance of the battery cell to foreign object penetration.

[0135] The specific experimental steps of the micro-short circuit test method are as follows:

[0136] Twenty batteries were prepared for each experimental example and comparative example. When the batteries were placed in the shell, 50 μm SUS particles were added between the shell and the battery cell. The batteries were encapsulated and filled with liquid. The batteries were charged at room temperature (25°C) in a constant current (0.05C) mode. Charging was stopped when the voltage reached 3.65V. The batteries were left to stand for 1 hour and then discharged at a current of 1C. Discharging was stopped when the voltage reached 2.7V.

[0137] The battery is clamped and vibrated under a force of 15kN, cycled for 500CLS at room temperature, and then self-discharged. The self-discharge test involves charging the battery to full capacity at 1 / 3C, leaving it at room temperature (25°C) for 7 days, then measuring its capacity and calculating its self-discharge rate. A self-discharge rate of less than 10% is considered acceptable.

[0138] The electrolyte infiltration efficiency method used in this embodiment is as follows: 20 batteries are selected for each group of embodiments and comparative examples, 320g of electrolyte is injected, the batteries are allowed to stand for 8 hours, and the free electrolyte is extracted. The electrolyte infiltration efficiency = (amount of injected electrolyte - amount of free electrolyte) / amount of injected electrolyte. If the electrolyte infiltration efficiency is less than 90%, the infiltration effect is poor, which affects the battery mass production efficiency.

[0139] Combined with Table 1 below, it is a statistical table of test results related to area S and area T.

[0140] In Examples 1 to 20, the value of S is 800 mm. 2 ≤S≤72000mm 2 ; The value of T must meet 11200mm 2 ≤T≤75000mm 2 , and the S / T values ​​all satisfy 0.02≤S / T≤6.2. Through the statistics of electrolyte infiltration efficiency and micro-short-circuit experiments, it can be seen that the electrolyte infiltration efficiency of Examples 1 to 20 is greater than 90%, the infiltration effect is good, and the battery mass production efficiency can be better guaranteed; and the self-discharge rate of the battery in the micro-short-circuit experiment is less than 10%, which meets the performance requirements.

[0141] In comparative example 1, although the values ​​of S all meet 800mm 2 ≤S≤72000mm 2 ; The value of T must meet 11200mm 2 ≤T≤75000mm 2 However, the S / T value is only 0.01, which cannot meet 0.02≤S / T≤6.2. Through the statistics of electrolyte infiltration efficiency and micro-short circuit experiments, it can be seen that the electrolyte infiltration efficiency of Comparative Example 1 is less than 90%, and the infiltration effect is poor, which affects the battery mass production efficiency.

[0142] In comparative example 2, although the value of S is 800 mm, 2 ≤S≤72000mm 2 ; The value of T must meet 11200mm 2 ≤T≤75000mm 2 However, the S / T value is 6.43, which cannot meet the requirement of 0.02≤S / T≤6.2. According to the statistics of electrolyte infiltration efficiency and micro-short-circuit test, it can be seen that the self-discharge rate of the battery in the micro-short-circuit test of Comparative Example 2 is greater than 10%, which cannot meet the performance requirements.

[0143] Table 1

[0144] parameter S T S / T Electrolyte wetting efficiency Micro short circuit test Example 1 1480 75000 0.02 90.10％ 0 Example 2 71500 11500 6.22 96.20％ 9％ Example 3 930 13000 0.07 92.20％ 0 Example 4 70000 20800 3.37 93.40％ 2％ Example 5 65000 54500 1.19 91.50％ 0 Example 6 48000 56000 0.86 90.80％ 1％ Example 7 72000 14500 4.97 94.30％ 3％ Example 8 21500 65000 0.33 91.00％ 0 Example 9 800 15300 0.05 90.50％ 0 Example 10 1980 35800 0.06 90.60％ 0 Example 11 4500 11800 0.38 91.20％ 0 Example 12 58000 19800 2.93 92.30％ 2％ Example 13 65000 11200 5.8 95.30％ 7％ Example 14 7800 35000 0.22 90.20％ 0 Example 15 38050 34700 1.1 91.10％ 1％ Example 16 39740 40800 0.97 90.90％ 0 Example 17 41430 46900 0.88 90.80％ 0 Example 18 43120 53000 0.81 90.70％ 0 Example 19 44810 59100 0.76 90.70％ 0 Example 20 46500 65200 0.71 90.10％ 0 Comparative Example 1 800 74800 0.01 88.10％ 0 Comparative Example 2 72000 11200 6.43 96.40％ 11％

[0145] Combined with Table 2 below, it is a statistical table of test results related to area S1, area S2 and area T.

[0146] In Examples 21 to 40, the value of S1 is 800 mm. 2 ≤S1≤57000mm 2 ; The value of T must meet 11200mm 2 ≤T≤75000mm 2 , and the values ​​of S1 / T all meet 0.02≤S1 / T≤4.8, and the values ​​of S2 all meet 800mm 2 ≤S2≤54000mm 2 , and the value of (S1+S2) / T all satisfies 0.03≤(S1+S2) / T≤4.8; through the statistics of electrolyte infiltration efficiency and micro-short-circuit experiments, it can be seen that the electrolyte infiltration efficiency of Examples 21 to 40 is greater than 90%, the infiltration effect is good, and the battery mass production efficiency can be better guaranteed; and the self-discharge rate of the battery in the micro-short-circuit experiment is less than 10%, which meets the performance requirements.

[0147] In comparative example 3, although the value of S1 satisfies 800mm 2 ≤S1≤57000mm 2 ; The value of T meets 11200mm 2 ≤T≤75000mm 2 , the value of S2 satisfies 800mm 2 ≤S2≤54000mm 2 However, the value of S1 / T is 0.01, and the value of S1 / T does not satisfy 0.02≤S1 / T≤4.8. The value of (S1+S2) / T is 0.02, and the value of (S1+S2) / T does not satisfy 0.03≤(S1+S2) / T≤4.8. Through the statistics of electrolyte wetting efficiency and micro-short circuit experiments, it can be seen that the electrolyte wetting efficiency of Comparative Example 3 is less than 90%, and the wetting effect is poor, which affects the battery mass production efficiency.

[0148] In comparative example 4, although the value of S1 satisfies 800mm 2 ≤S1≤57000mm 2 ; The value of T meets 11200mm 2 ≤T≤75000mm 2 , the value of S2 satisfies 800mm 2 ≤S2≤54000mm 2However, the value of S1 / T is 5.09, and the value of S1 / T does not satisfy 0.02≤S1 / T≤4.8. The value of (S1+S2) / T is 5.16, and the value of (S1+S2) / T does not satisfy 0.03≤(S1+S2) / T≤4.8. Through the statistics of electrolyte infiltration efficiency and micro-short-circuit experiments, it can be seen that the self-discharge rate of the battery in the micro-short-circuit experiment of Comparative Example 4 is greater than 10%, which cannot meet the performance requirements.

[0149] Table 2

[0150]

[0151] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the present invention.

Claims

1. A battery, characterized in that: include: At least two battery cells (2) stacked along the X direction; The battery cell (2) comprises: a positive electrode sheet (51) and a negative electrode sheet (52); a separator film layer (6) located between the positive electrode sheet (51) and the negative electrode sheet (52), and the separator film layer (6) is at least partially located on the outer surface of the battery cell (2); and an outer coating layer (4), the outer coating layer (4) is at least partially arranged on the outer surface of the separator film layer (6) forming the outer surface of the battery cell; The battery core (2) is defined as having a straight section (201), and the surfaces of the straight sections (201) of two adjacent battery cores (2) that are arranged opposite to each other are adjacent surfaces, and the adjacent surfaces are perpendicular to the X direction; The area where the positive electrode sheet (51) overlaps with the adjacent surface projection along the X direction is defined as a first projection surface; The outer coating layer (4) is respectively provided on the adjacent surfaces of two adjacent battery cells (2), and the projections of the outer coating layers (4) respectively located on the two adjacent surfaces on the first projection plane along the X direction do not overlap; The area of ​​the first projection surface is T; the area outside the projection of the outer coating layer (4) respectively located on the two adjacent surfaces on the first projection surface is S, which satisfies the following: 0.02≤S / T≤6.2; The value of S satisfies: 800mm 2 ≤S≤72000mm 2 ; Along the height direction of the battery core, the height of the positive electrode sheet (51) is smaller than the height of the negative electrode sheet (52), and the height of the negative electrode sheet (52) is smaller than the height of the separator film layer (6); the height of the outer film layer (4) is greater than the height of the positive electrode sheet (51); The minimum distance between the edge of the outer coating layer (4) along the height direction of the battery core and the positive electrode sheet (51) along the height direction of the battery core is not less than 1 mm.

2. The battery according to claim 1, characterized in that The value of T meets: 11200mm 2 ≤T≤75000mm 2 .

3. The battery according to claim 1, characterized in that The non-overlapping area of ​​the outer coating layer (4) located on the two adjacent surfaces along the X direction with the projection of the first projection surface includes a first non-overlapping area, which satisfies: 0.02≤S1 / T≤4.8, wherein S1 is the area when the first non-overlapping area is at the middle position of the straight section (201).

4. The battery according to claim 3, characterized in that The value of S1 satisfies: 800mm 2 ≤S1≤57000mm 2 .

5. The battery according to claim 3, characterized in that The tail end of at least one of the outer coating layers (4) extends beyond the straight section (201) of the battery core (2).

6. The battery according to claim 5, characterized in that Satisfies: 0.03≤S1 / T≤4.

65.

7. The battery according to claim 5, characterized in that The tail end of at least one of the outer coating layers (4) extends to the arc-shaped R corner (202) of the battery core (2).

8. The battery according to claim 7, characterized in that Satisfies: 0.16≤S1 / T≤4.

65.

9. The battery according to claim 7, characterized in that The battery core (2) is a wound battery core, and the tail end of the outer coating layer (4) extends to the arc-shaped R corner (202) of the battery core (2).

10. The battery according to claim 7, characterized in that The tail end of at least one of the outer covering film layers (4) extends to the opposite side of the adjacent surface.

11. The battery according to claim 10, characterized in that Meets: 2.0≤S1 / T≤4.

8.

12. The battery according to claim 10, characterized in that The tail end of the outer coating layer (4) continues to extend beyond the opposite surface of the adjacent surface of the battery core (2).

13. The battery according to claim 12, characterized in that Meets: 2.1≤S1 / T≤4.

8.

14. The battery according to claim 12, characterized in that The battery core (2) is a wound battery core, and the tail end of the outer coating layer (4) continues to extend to the arc-shaped R corner (202) on the other side of the battery core (2).

15. The battery according to claim 14, characterized in that Meets: 3.1≤S1 / T≤4.

8.

16. The battery according to claim 1, characterized in that The non-overlapping areas of the outer coating layer (4) respectively located on the two adjacent surfaces with the projection of the first projection plane along the X direction include a first non-overlapping area and a second non-overlapping area, wherein the first non-overlapping area is located in the middle of the straight section (201), and the second non-overlapping area is located on one side of the straight section (201).

17. The battery according to claim 16, characterized in that It satisfies: 0.03≤(S1+S2) / T≤4.8, where S1 is the area of ​​the first non-overlapping area; S2 is the area of ​​the second non-overlapping area.

18. The battery according to claim 17, characterized in that The value of S2 satisfies: 800mm 2 ≤S2≤54000mm 2 .

19. The battery according to claim 17, characterized in that Satisfies: 0.01≤S1 / S2≤71.

20. The battery according to claim 1, characterized in that The non-overlapping areas of the outer coating layer (4) respectively located on the two adjacent surfaces with the projection of the first projection plane along the X direction include a first non-overlapping area, a second non-overlapping area and a third non-overlapping area, wherein the first non-overlapping area is located in the middle of the straight section (201), and the second non-overlapping area and the third non-overlapping area are respectively located on both sides of the straight section (201).

21. The battery according to claim 20, characterized in that Satisfies: 0.03≤(S1+S2+S3) / T≤4.8, where S1 is the area of ​​the first non-overlapping area; S2 is the area of ​​the second non-overlapping area; and S3 is the area of ​​the second non-overlapping area.

22. The battery according to claim 21, characterized in that Satisfies: 0.03≤(S2+S3) / S1≤67.

5.

23. The battery according to claim 21, characterized in that The value of S3 satisfies: 800mm 2 ≤S3≤54000mm 2 .

24. The battery according to claim 1, characterized in that The thicknesses of the outer coating layers (4) of two adjacent battery cells (2) are Q1 and Q2 respectively, satisfying the following relationship: 0.8≤Q1 / Q2≤1.

2.

25. The battery according to claim 1, characterized in that The sum of the thicknesses of the outer coating layers (4) of two adjacent battery cells (2) is Q1+Q2, and the thickness of a single battery cell (2) along the X direction is D, satisfying the following conditions: 1.2≥Q1 / Q2≥1, 20mm≤D≤40mm.

26. The battery according to claim 1, characterized in that The thickness of the outer film layer (4) of the battery cell (2) is Q; the outer film layer (4) located on two adjacent surfaces, respectively, and the non-overlapping area with the projection of the first projection plane along the X direction includes a first non-overlapping area, and the area of ​​the first non-overlapping area when it is the middle position of the straight section (201) is S1, which satisfies: 8.8×10 -8 ≤Q / S1≤2.5×10 -4 .

27. The battery according to claim 1, characterized in that The minimum distance between the edge of the outer coating layer (4) along the height direction of the battery core and the edge of the separation film layer (6) along the height direction of the battery core is in the range of 1 mm to 5 mm.

28. The battery according to claim 1, characterized in that The separation film layer (6) forms a tail portion (61) on the outer surface of the battery cell (2); the outer surface of the battery cell (2) is located in an area outside the tail portion (61) to form a non-tail portion; the head end of the outer film layer (4) is fixed to the outside of the tail portion (61), and the outer film layer (4) covers the boundary line between the tail portion (61) and the non-tail portion, and the tail end of the outer film layer (4) extends to the non-tail portion; The tail portions (61) of two adjacent battery cells (2) are both located on opposite sides of the adjacent surface.

29. The battery according to claim 1, characterized in that The separation film layer (6) forms a tail portion (61) on the outer surface of the battery cell (2); the outer surface of the battery cell (2) is located in an area outside the tail portion (61) to form a non-tail portion; the head end of the outer film layer (4) is fixed to the outside of the tail portion (61), and the outer film layer (4) covers the boundary line between the tail portion (61) and the non-tail portion, and the tail end of the outer film layer (4) extends to the non-tail portion; The tail portions (61) of two adjacent battery cells (2) are both located on the adjacent surface.

30. The battery according to claim 1, wherein The thickness of a single battery core (2) along the X direction is D, which satisfies the following relationship: 0.0003≤D / S≤0.

05.

31. The battery according to claim 1, wherein The thickness of the separation membrane layer (6) is F, which satisfies: F≥3 μm; at this time, the range of S / T satisfies: 0.05≤S / T≤6.

2.

32. The battery according to claim 1, characterized in that The porosity of the separation membrane layer (6) is a, which satisfies: a≥20%; at this time, the range of S / T satisfies: 0.02≤S / T≤5.

9.

33. A battery pack, characterized in that: A battery comprising a battery as claimed in any one of claims 1 to 32.

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