Battery, battery pack and preparation method of battery

Abstract

The invention relates to the technical field of batteries, and discloses a battery, a battery pack and a preparation method of the battery, and the battery comprises a pole group, a first packaging film and a second packaging film; the first packaging film is provided with a containing groove used for installing the pole group, and the pole group is arranged in the containing groove; the second packaging film is arranged opposite to the first packaging film, and a hot melting area surrounding the periphery of the accommodating groove is reserved between the second packaging film and the first packaging film; the hot melting areas of the first packaging film and the second packaging film are respectively provided with a plurality of rows of embossments, the plurality of rows of embossments are arranged around the periphery of the pole group, the distance L1 between the adjacent embossments in the width direction of the battery is more than or equal to 0.1 mm and less than or equal to 3mm, and the distance L2 between the adjacent embossments in the length direction of the battery is more than or equal to 0.1 mm and less than or equal to 3mm. The multiple rows of knurls are arranged in the hot melting area, and the distance between every two adjacent knurls is limited, so that the hot melting uniformity of the hot melting layer can be improved, the sealing effect is improved, and the service life of the hot melting pressing head is prolonged.

Description

Technical Field

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

[0002] The battery is mainly composed of a pole lug, a pole group, and a packaging film. The packaging film encapsulates the pole group and the pole lug and seals them by hot pressing. It has the advantages of light weight, low mold cost, and high safety.

[0003] However, in the existing hot pressing process of batteries, the hot melt press head has high requirements on flatness. The hot melt press head will continue to wear during use. After a period of time, the width of the hot melt layer formed by the hot melt press head is prone to inconsistency, resulting in the local width of the hot melt layer becoming narrower and the tensile strength becoming worse, which ultimately leads to the failure of the hot melt seal. Summary of the invention

[0004] In view of this, the present invention provides a battery, a battery pack and a method for preparing a battery to solve the problem that the hot melt pressure head has a high requirement for flatness and the hot melt sealing is poor after being used for a period of time.

[0005] In a first aspect, the present invention provides a battery, comprising:

[0006] Pole group;

[0007] A first packaging film, on which a receiving groove for mounting the electrode group is provided, and the electrode group is arranged in the receiving groove;

[0008] A second packaging film is arranged opposite to the first packaging film and has a hot-melt area around the receiving groove reserved in the first packaging film;

[0009] The hot melt zones of the first packaging film and the second packaging film are respectively provided with multiple rows of embossings, and the multiple rows of embossings are arranged around the electrode group. The spacing L1 of adjacent embossings in the width direction of the battery satisfies 0.1mm≤L1≤3mm, and the spacing L2 of adjacent embossings in the length direction of the battery satisfies 0.1mm≤L2≤3mm.

[0010] Beneficial effects: The battery of the present invention is pre-equipped with multiple rows of embossings in the hot melt areas of the first packaging film and the second packaging film, respectively, and the spacing between adjacent embossings in the length and width directions of the battery is limited. The embossing can be used to reduce the flatness requirements of the hot melt head, improve the uniformity of hot melt, ensure the consistency of the width of the hot melt layer, and improve the tensile strength of the hot melt layer, thereby improving the sealing performance, which is beneficial to improving the structural stability of the battery and also beneficial to improving the service life of the hot melt head.

[0011] In an optional embodiment, the first packaging film and the second packaging film are fixed together by hot-melt molding at the positions where the embossing is provided in the hot-melt areas to form a hot-melt layer, so as to encapsulate the electrode group in the receiving groove.

[0012] Beneficial effects: During assembly, the electrode group is first installed in the receiving groove of the first packaging film, and then the second packaging film is covered on the first packaging film. The hot melt pressure head is used to heat and pressurize the embossed outer surfaces of the hot melt areas of the first packaging film and the second packaging film, so that a hot melt layer is formed at the embossed position of the hot melt area. The first packaging film and the second packaging film are fixed by hot melting the hot melt layer to encapsulate the electrode group in the receiving groove. The manufacturing is simple and easy to promote.

[0013] In an optional embodiment, the bottom surface of the embossing is rectangular, and the length L3 of the bottom surface of the embossing satisfies 0.1mm≤L3≤20mm;

[0014] And / or, the bottom width W1 of the embossing satisfies 0.1 mm≤W1≤5 mm.

[0015] Beneficial effects: By limiting the bottom length and bottom width of the embossing, the consistency of the width of the hot melt layer can be further ensured, the deviation can be reduced, and the occupied width of the hot melt zone can be maintained within an appropriate range, thereby reducing the overall size of the battery and saving materials.

[0016] In an optional embodiment, the depth H1 of each embossing satisfies 0.02 mm≤H1≤0.2 mm.

[0017] Beneficial effect: By limiting the embossing depth, it is possible to ensure that the hot melt zone has embossing of appropriate size, further improving the uniformity of the hot melt process and the consistency of the width of the hot melt layer.

[0018] In an optional implementation, the embossing depth H1 and the thickness H2 of the first packaging film and the thickness H3 of the second packaging film satisfy 0.1≤H1 / H2≤0.5 and 0.1≤H1 / H3≤0.5.

[0019] Beneficial effect: By limiting the relationship between the embossing depth and the thickness of the first packaging film and the second packaging film, it is possible to avoid overflow of the hot melt layer caused by overpressure, ensure that the remaining connecting material of the hot melt layer has a suitable thickness, and ensure that the hot melt layer has good connection strength.

[0020] In an optional implementation, a thickness H2 of the first packaging film is equal to a thickness H3 of the second packaging film.

[0021] Beneficial effects: The thickness of the first packaging film is equal to the thickness of the second packaging film, which is beneficial to maintaining the structural balance of the battery, reducing stress concentration, improving the overall stability of the battery, and reducing the difficulty of designing the depth of the receiving groove.

[0022] In an optional embodiment, the projection area S of a single embossing in the thickness direction of the battery satisfies 0.1 mm 2 ≤S≤100mm 2 .

[0023] Beneficial effect: By limiting the projection area of ​​a single embossing in the thickness direction of the battery, it is possible to ensure that a single embossing has a sufficiently large area, thereby improving the uniformity of hot melting.

[0024] In an optional embodiment, the cross-sectional shape of a single embossment includes a regular shape and an irregular shape, and the regular shape includes at least one of an inverted trapezoid, a square, a circle, and a triangle;

[0025] When the cross section of the embossing is an inverted trapezoid, the inclination angle β of the inverted trapezoid satisfies 30°≤β≤85°.

[0026] Beneficial effects: The cross-sectional shape of the embossing can be selected and set according to actual needs to meet the needs of product diversification and personalization. The cross-sectional shape of the embossing is an inverted trapezoid, which is convenient for manufacturing and use. By limiting the inclination angle of the inverted trapezoid, it is possible to avoid the corners of the embossing from damaging the first packaging film and the second packaging film.

[0027] In a second aspect, the present invention further provides a battery pack, comprising: the above-mentioned battery.

[0028] Beneficial effect: Since the battery pack includes a battery, it has the same effect as the battery and will not be described in detail here.

[0029] In a third aspect, the present invention further provides a method for preparing a battery, comprising:

[0030] Prepare a first packaging film and a second packaging film, form a receiving groove on the first packaging film, and reserve a hot melt area around the first packaging film and the second packaging film;

[0031] Installing the electrode group in the receiving groove of the first packaging film;

[0032] The hot melt zones of the first packaging film and the second packaging film are respectively provided with multiple rows of embossings, and the multiple rows of embossings are arranged around the electrode group. The spacing L1 of adjacent embossings in the width direction of the battery satisfies 0.1mm≤L1≤3mm, and the spacing L2 of adjacent embossings in the length direction of the battery satisfies 0.1mm≤L2≤3mm.

[0033] Beneficial effects: The preparation method of the battery provided by the present invention prepares the first packaging film and the second packaging film in advance, and the first packaging film and the second packaging film are respectively reserved with hot melt areas around the receiving groove. The hot melt layer can be formed to fix the first packaging film and the second packaging film by heating and pressurizing the preset position of the hot melt area through the hot melt pressure head, and the electrode group is packaged in the receiving groove. Multiple rows of embossing are set in the hot melt area in advance, and the spacing between adjacent embossings in the length and width directions of the battery is limited. The embossing can be used to reduce the requirements of the hot melt pressure head on flatness, improve the uniformity of hot melt, ensure the consistency of the width of the hot melt layer, and improve the tensile strength of the hot melt layer, so as to achieve better sealing, which is beneficial to improving the structural stability of the battery, and also improves the service life of the hot melt pressure head. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic diagram of the structure of a battery according to an embodiment of the present invention;

[0036] Figure 2 for Figure 1 A cross-sectional view of the AA battery shown;

[0037] Figure 3 for Figure 2 A partial enlarged schematic diagram of B in the middle;

[0038] Figure 4 This is a schematic structural diagram of a first packaging film of a battery according to an embodiment of the present invention;

[0039] Figure 5 for Figure 4 A partial enlarged schematic diagram of C in the middle;

[0040] Figure 6 for Figure 5 A cross-sectional view taken along line DD of the first packaging film shown;

[0041] Figure 7 for Figure 6 A partial enlarged schematic diagram of middle E;

[0042] Figure 8 This is a schematic structural diagram of a second packaging film of a battery according to an embodiment of the present invention;

[0043] Fig. 9 for Figure 8 A partial enlarged schematic diagram of F in the middle.

[0044] Description of reference numerals:

[0045] 1. Pole group; 101. Positive electrode ear; 102. Negative electrode ear; 2. First packaging film; 201. Receiving groove; 3. Second packaging film; 4. Hot melt area; 5. Embossing; 6. Hot melt layer; 7. Hot melt pressure head. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the 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 creative work are within the scope of protection of the present invention.

[0047] Combine the following Figures 1 to 9 , describing an embodiment of the present invention.

[0048] According to an embodiment of the present invention, on one hand, a battery is provided, comprising: an electrode group 1, a first packaging film 2, a second packaging film 3 and a hot melt layer 6. The first packaging film 2 is provided with a receiving groove 201 for mounting the electrode group 1, the electrode group 1 is arranged in the receiving groove 201, the second packaging film 3 is arranged opposite to the first packaging film 2 and the first packaging film 2 respectively reserves a hot melt area 4 around the receiving groove 201. The hot melt areas 4 of the first packaging film 2 and the second packaging film 3 are respectively provided with multiple rows of embossings 5, the multiple rows of embossings 5 ​​are arranged around the electrode group 1 and connected end to end, the spacing L1 of adjacent embossings 5 ​​in the width direction of the battery satisfies 0.1mm≤L1≤3mm, and the spacing L2 of adjacent embossings 5 ​​in the length direction of the battery satisfies 0.1mm≤L2≤3mm.

[0049] The battery provided in the embodiment of the present invention is pre-equipped with multiple rows of embossings 5 ​​in the hot melt areas 4 of the first packaging film 2 and the second packaging film 3, respectively, and the spacing between adjacent embossings 5 ​​in the length and width directions of the battery is limited. The embossings 5 ​​can be used to reduce the flatness requirements of the hot melt head 7, improve the uniformity of hot melting, ensure the consistency of the width of the hot melt layer 6, and improve the tensile strength of the hot melt layer 6, so as to achieve better sealing, which is beneficial to improving the structural stability of the battery and also beneficial to improving the service life of the hot melt head 7.

[0050] For details, please refer to the width direction of the battery. Figure 4 and Figure 5 The width direction of the embossing 5 is consistent with the width direction of the battery. Similarly, the length direction of the battery can be found in Figure 4 and Figure 5 As shown in the figure, the length direction of the embossing 5 is consistent with the length direction of the battery. Figure 4 and Figure 8 In the embodiment of the present invention, the hot melt area 4 of the first packaging film 2 and the second packaging film 3 are respectively provided with multiple rows of embossing 5. After packaging, the embossing 5 is located on the inner side of the first packaging film 2 and the second packaging film 3, and the hot melt head 7 heats the corresponding outer surface of the hot melt area 4. The following definition of the relevant dimensions of the embossing 5 is applicable to both the first packaging film 2 and the second packaging film 3.

[0051] In one embodiment, the first packaging film 2 and the second packaging film 3 are fixed together by hot-melt molding at the locations where the hot-melt regions 4 are provided with embossings 5 ​​to form a hot-melt layer 6 to encapsulate the electrode group 1 in the receiving groove 201 .

[0052] During assembly, the electrode group 1 is first installed in the receiving groove 201 of the first packaging film 2, and then the second packaging film 3 is covered on the first packaging film 2. The outer surface of the hot melt area 4 of the first packaging film 2 and the second packaging film 3 with embossing 5 is heated and pressurized by a hot melt pressure head 7, so that a hot melt layer 6 is formed at the position of the embossing 5 in the hot melt area 4. The first packaging film 2 and the second packaging film 3 are fixed by hot melting through the hot melt layer 6 to encapsulate the electrode group 1 in the receiving groove 201. The manufacturing is simple and it is easy to promote.

[0053] In one embodiment, see Figures 1 to 3 The battery can be a rectangular structure, the first packaging film 2 and the second packaging film 3 are correspondingly square sheets, and multiple rows of embossing 5 are connected end to end around the electrode group 1 to form a rectangular ring-shaped embossing area. The first packaging film 2 is formed by stamping to form a receiving groove 201. The electrode group 1 is installed in the receiving groove 201, that is, the electrode group 1 is wrapped by the first packaging film 2 and the second packaging film 3. A polypropylene layer (PP layer) is provided in the inner layer of the first packaging film 2 and the second packaging film 3 respectively, and the polypropylene layer in the hot melt area 4 is heated and pressurized by the hot melt pressure head 7 to melt and form a hot melt layer 6.

[0054] Of course, in other alternative embodiments, the battery may also be in other shapes, such as a disc shape, an elliptical cylinder shape, etc. Correspondingly, the first packaging film 2, the second packaging film 3 and the electrode group 1 are adapted to be arranged.

[0055] It should be noted that the materials of the first packaging film 2 and the second packaging film 3 of the embodiment of the present invention can be selected according to actual conditions. For example, the first packaging film 2 and the second packaging film 3 are aluminum-plastic films.

[0056] In one embodiment, see Figure 4 and Figure 5The bottom surface of the embossing 5 is rectangular, the bottom surface length L3 of the embossing 5 satisfies 0.1mm≤L3≤20mm, and / or the bottom surface width W1 of the embossing 5 satisfies 0.1mm≤W1≤5mm. By limiting the bottom surface length and bottom surface width of the embossing 5, the consistency of the width of the hot melt layer 6 can be further ensured, the deviation can be reduced, and the occupied width of the hot melt area 4 can be maintained within a suitable range, thereby reducing the overall size of the battery and saving materials.

[0057] It should be noted that if the bottom length of the embossing 5 is too large, the width of the hot melt layer 6 is prone to be uneven and have a large deviation, and the width of the local hot melt layer 6 is too small. If the bottom width of the embossing 5 is too large, the width occupied by the hot melt area 4 is too large, resulting in a larger overall size of the battery and a waste of materials.

[0058] In one embodiment, see Figure 6 and Figure 7 , the depth H1 of each embossing 5 satisfies 0.02mm≤H1≤0.2mm. By limiting the depth of the embossing 5 and limiting the projection area of ​​the embossing 5 in the thickness direction of the battery, it is possible to ensure that the hot melt zone 4 has an appropriate volume of embossing 5, further improving the uniformity of the hot melt process and the consistency of the width of the hot melt layer 6.

[0059] Further, in one embodiment, see Figure 6 and Figure 7 , the depth H1 of the embossing 5 and the thickness H2 of the first packaging film 2 and the thickness H3 of the second packaging film 3 satisfy 0.1≤H1 / H2≤0.5, 0.1≤H1 / H3≤0.5. By limiting the relationship between the depth of the embossing 5 and the thickness of the first packaging film 2 and the second packaging film 3, it is possible to avoid the overflow of the hot melt layer 6 caused by overpressure, ensure that the remaining connecting material of the hot melt layer 6 has a suitable thickness, and ensure that the hot melt layer 6 has a good connection force.

[0060] Furthermore, in one embodiment, the thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness of the first packaging film 2 is equal to the thickness of the second packaging film 3, which is conducive to maintaining the structural balance of the battery, reducing stress concentration, improving the overall stability of the battery, and reducing the difficulty of designing the depth of the receiving groove 201.

[0061] In one embodiment, the projection area S of a single embossing 5 in the thickness direction of the battery satisfies 0.1 mm 2 ≤S≤100mm 2 By limiting the projection area of ​​a single embossing 5 in the thickness direction of the battery, it is possible to ensure that a single embossing 5 has a sufficiently large area, thereby improving the uniformity of hot melting.

[0062] It should be noted that the number of rows of the embossing 5 can be two, three or more rows as required. If the spacing between adjacent embossings 5 ​​is too large, the width of the hot-melt layer 6 at the spacing between the embossings 5 ​​is too small.

[0063] In addition, the embodiment of the present invention does not limit the shape of the embossing 5. The cross-sectional shape of a single embossing 5 includes a regular shape and an irregular shape, and the regular shape includes at least one of an inverted trapezoid, a square, a circle, and a triangle. The cross-sectional shape of the embossing 5 can be selected and set according to actual needs to meet the needs of product diversification and personalization.

[0064] In one embodiment, see Figure 7 The cross section of each embossing 5 is an inverted trapezoid, which is convenient for manufacturing and use. The inclination angle β of the inverted trapezoid satisfies 30°≤β≤85°. The inclination angle β of the inverted trapezoid is the angle between the inverted trapezoid and the surface of the packaging film on which the embossing 5 is provided. By limiting the inclination angle β of the inverted trapezoid, it is possible to prevent the corners of the inverted trapezoidal embossing 5 from damaging the first packaging film 2 and the second packaging film 3.

[0065] In one embodiment, see Figure 1 , positive electrode ears 101 and negative electrode ears 102 are respectively provided at opposite ends of the length direction of the electrode group 1, and the positive electrode ears 101 and negative electrode ears 102 extend outside the first packaging film 2 and the second packaging film 3. The positive electrode ears 101 and the negative electrode ears 102 are installed at opposite ends of the length direction of the electrode group 1, which facilitates the connection and layout of the positive electrode ears 101 and the negative electrode ears 102 with the connecting sheet. The positive electrode ears 101 and the negative electrode ears 102 extend outside the first packaging film 2 and the second packaging film 3, which is conducive to improving the sealing of the first packaging film 2 and the second packaging film 3.

[0066] Specifically, the positive electrode tab 101 and the negative electrode tab 102 may be in a similar rectangular sheet structure, with a large welding area, so as to facilitate welding and assembly of the positive electrode tab 101 and the negative electrode tab 102 .

[0067] The process parameters of the battery according to the embodiment of the present invention are further described in detail below in conjunction with specific embodiments. These examples should not be construed as limiting the scope of protection claimed by the present invention.

[0068] Embodiment 1:

[0069] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 2 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 2 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 19 mm. At this time, the bottom surface length L3 of the embossing 5 is biased to the maximum value. The depth H1 of the embossing 5 is 0.1 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.25 mm, then H1 / H2 is 0.4. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 60°. The results of the battery production line test verification are shown in Table 1.

[0070] Embodiment 2:

[0071] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 3mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 1mm. At this time, the spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is the maximum. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 3mm. The depth H1 of the embossing 5 is 0.04mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.25mm, then H1 / H2 is 0.16. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 70°. The results of the battery production line test verification are shown in Table 1.

[0072] Embodiment 3:

[0073] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 1 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 2.9 mm. At this time, the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is biased towards the maximum value. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 3 mm. The depth H1 of the embossing 5 is 0.1 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.25 mm, then H1 / H2 is 0.4. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 70°. The results of the battery production line test verification are shown in Table 1.

[0074] Embodiment 4:

[0075] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 1 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 1 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 15 mm. The depth H1 of the embossing 5 is 0.2 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.4 mm, then H1 / H2 is 0.5, at this time, H1 / H2 is the maximum value. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 40°. The results of the battery production line test verification are shown in Table 1.

[0076] Embodiment 5:

[0077] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 2.5 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 2 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 15 mm. The depth H1 of the embossing 5 is 0.02 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. If the thickness H2 of the first packaging film 2 is 0.2 mm, then H1 / H2 is 0.1, and at this time, H1 / H2 is the minimum value. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 40°. The results of the battery production line test verification are shown in Table 1.

[0078] Embodiment 6:

[0079] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 2.5 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 2.5 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 8 mm. The depth H1 of the embossing 5 is 0.05 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.15 mm, then H1 / H2 is 0.33. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 85°, at this time, β is the maximum value. The results of the battery production line test verification are shown in Table 1.

[0080] Embodiment 7:

[0081] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 2 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 2 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 3 mm. The depth H1 of the embossing 5 is 0.06 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.15 mm, then H1 / H2 is 0.4. The cross section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 60°. The results of the battery production line test verification are shown in Table 1.

[0082] Comparative Example 1:

[0083] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 2 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 1 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 21 mm, that is, L3 is greater than 20 mm. The depth H1 of the embossing 5 is 0.1 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.25 mm, then H1 / H2 is 0.4. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 50°. The results of the battery production line test verification are shown in Table 1.

[0084] Comparative Example 2:

[0085] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 3.2 mm, that is, L1 is greater than 3 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 2 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 3 mm. The depth H1 of the embossing 5 is 0.1 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.25 mm, then H1 / H2 is 0.4. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 40°. The results of the battery production line test verification are shown in Table 1.

[0086] Comparative Example 3:

[0087] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 2 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 3.1 mm, that is, L2 is greater than 3 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 3 mm. The depth H1 of the embossing 5 is 0.06 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.15 mm, then H1 / H2 is 0.4. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 40°. The results of the battery production line test verification are shown in Table 1.

[0088] Comparative Example 4:

[0089] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 1 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 2 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 2 mm. The depth H1 of the embossing 5 is 0.18 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.35 mm, then H1 / H2 is 0.51, that is, H1 / H2 is greater than 0.5. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 60°. The results of the battery production line test verification are shown in Table 1.

[0090] Comparative Example 5:

[0091] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 1 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 1 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 2 mm. The depth H1 of the embossing 5 is 0.03 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.33 mm, then H1 / H2 is 0.09, that is, H1 / H2 is less than 0.1. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 60°. The results of the battery production line test verification are shown in Table 1.

[0092] Comparative Example 6:

[0093] The spacing L1 between adjacent embossings 5 ​​in the width direction of the battery is 2 mm, and the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery is 2 mm. The bottom surface of the embossing 5 is rectangular, and the bottom surface length L3 is 2 mm. The depth H1 of the embossing 5 is 0.05 mm. The thickness H2 of the first packaging film 2 is equal to the thickness H3 of the second packaging film 3. The thickness H2 of the first packaging film 2 is 0.15 mm, then H1 / H2 is 0.33. The cross-section of the embossing 5 is an inverted trapezoid, and the inclination angle β of the inverted trapezoid is 87°, that is, β is greater than 85°. The results of the battery production line test verification are shown in Table 1.

[0094] Table 1: Test results

[0095]

[0096] It can be seen that in Examples 1 to 7, the spacing L1 between adjacent embossments 5 in the width direction of the battery satisfies 0.1mm≤L1≤3mm, the spacing L2 between adjacent embossments 5 in the length direction of the battery satisfies 0.1mm≤L2≤3mm, and the bottom length L3 of the embossment 5 satisfies 0.1mm≤L3≤20mm. The depth H1 of the embossment 5 satisfies 0.02mm≤H1≤0.2mm, and the depth H1 of the embossment 5 and the thickness H2 of the first packaging film 2 satisfy 0.1≤H1 / H2≤0.5. The inclination angle β of the inverted trapezoid satisfies 30°≤β≤85°, and the test results are normal, which can meet the hot melting conditions of the hot melt head 7, improve the hot melting uniformity, ensure the consistency of the width of the hot melt layer 6, and improve the tensile strength of the hot melt layer 6, so that the sealing is better, which is conducive to improving the structural stability of the battery, and also improves the service life of the hot melt head 7.

[0097] In comparative example 1, the bottom surface length L3 of the embossing 5 exceeds 20 mm. The peeling test found that the hot melt layer 6 has poor uniformity and large deviation, and there is a risk of leakage.

[0098] In comparative example 2, the spacing L1 between adjacent embossings 5 ​​in the width direction of the battery exceeds 3 mm. The peeling test found that the hot melt layer 6 had poor uniformity and large deviation, and there was a risk of leakage.

[0099] In comparative example 3, the spacing L2 between adjacent embossings 5 ​​in the length direction of the battery exceeds 3 mm. The peeling test found that the hot-melt layer 6 had poor uniformity and large deviation, and there was a risk of leakage.

[0100] In Comparative Example 4, H1 / H3 exceeds 0.5, the hot melt layer 6 has serious glue overflow, and after the electrode group 1 expands, the hot melt area 4 is peeled off, resulting in the failure of the battery seal.

[0101] In comparative example 5, H1 / H3 is less than 0.1, and after the electrode group 1 expands due to cyclic gas production, the hot melt zone 4 is peeled off, resulting in sealing failure of the battery; the conversion ratio between the hot melt head 7 width and the actual melt width is too poor.

[0102] In comparative example 6, the inclination angle β of the inverted trapezoid exceeds 85°, and the first packaging film 2 and the second packaging film 3 are crushed and cracked.

[0103] According to an embodiment of the present invention, on the other hand, a battery pack is provided, including: a battery.

[0104] Since the battery pack includes batteries and has the same effects as the batteries, they will not be described in detail here.

[0105] According to an embodiment of the present invention, in another aspect, a method for preparing a battery is provided, comprising:

[0106] S100, preparing a first packaging film 2 and a second packaging film 3, forming a receiving groove 201 on the first packaging film 2, and reserving a hot melt area 4 around the first packaging film 2 and the second packaging film 3;

[0107] S200 , installing the electrode group 1 in the receiving groove 201 of the first packaging film 2 .

[0108] S300, the hot melt areas 4 of the first packaging film 2 and the second packaging film 3 are respectively provided with multiple rows of embossings 5, and the multiple rows of embossings 5 ​​are arranged around the electrode group 1. The spacing L1 of adjacent embossings 5 ​​in the width direction of the battery satisfies 0.1mm≤L1≤3mm, and the spacing L2 of adjacent embossings 5 ​​in the length direction of the battery satisfies 0.1mm≤L2≤3mm.

[0109] In the method for preparing a battery provided in an embodiment of the present invention, the first packaging film 2 and the second packaging film 3 are prepared in advance, and the first packaging film 2 and the second packaging film 3 are respectively reserved with a hot melt area 4 around the receiving groove 201. The hot melt layer 6 is formed to fix the first packaging film 2 and the second packaging film 3 by heating and pressurizing the preset position of the hot melt area 4 by the hot melt press head 7, and the electrode group 1 is packaged in the receiving groove 201. Multiple rows of embossing 5 are pre-arranged in the hot melt area 4, and the spacing between adjacent embossings 5 ​​in the length and width directions of the battery is limited. The embossing 5 can be used to reduce the requirements of the hot melt press head 7 on flatness, improve the uniformity of hot melting, ensure the consistency of the width of the hot melt layer 6, and improve the tensile strength of the hot melt layer 6, so that the sealing is better, which is conducive to improving the structural stability of the battery, and also improves the service life of the hot melt press head 7.

[0110] In one embodiment, the method for preparing a battery further comprises:

[0111] S400, cover the second packaging film 3 on the first packaging film 2, set the hot melt pressure heads 7 at the preset positions of the hot melt area 4, and heat the preset positions of the hot melt area 4 at a preset temperature and a preset pressure to form a hot melt layer 6.

[0112] S500 , the first packaging film 2 and the second packaging film 3 are fixed together through the hot melt layer 6 to package the electrode group 1 in the receiving groove 201 .

[0113] Specifically, in step S400, the hot melt press heads 7 are respectively arranged on the outer surfaces of the hot melt areas 4 on opposite sides of the first packaging film 2 and the second packaging film 3, and the outer surfaces of the hot melt areas 4 provided with the embossing 5 are heated and pressurized to form a hot melt layer 6 at the embossing 5 of the hot melt areas 4. The temperature of the hot melt press head 7 is 50° C. to 200° C., and the pressure is 0.1 MPa to 1.0 MPa.

[0114] Although the embodiments of the present invention have been described in conjunction with 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 appended claims.

Claims

1. A battery, characterized in that: include: Pole group; A first packaging film, on which a receiving groove for mounting the electrode group is provided, and the electrode group is arranged in the receiving groove; A second packaging film is arranged opposite to the first packaging film and has a hot-melt area around the receiving groove reserved in the first packaging film; The hot melt zones of the first packaging film and the second packaging film are respectively provided with multiple rows of embossings, and the multiple rows of embossings are arranged around the electrode group. The spacing L1 of adjacent embossings in the width direction of the battery satisfies 0.1mm≤L1≤3mm, and the spacing L2 of adjacent embossings in the length direction of the battery satisfies 0.1mm≤L2≤3mm.

2. The battery according to claim 1, characterized in that The first packaging film and the second packaging film are fixed together by hot-melt molding at the positions where the embossing is provided in the hot-melt areas to form a hot-melt layer, so as to package the electrode group in the receiving groove.

3. The battery according to claim 1, characterized in that The bottom surface of the embossing is rectangular, and the length L3 of the bottom surface of the embossing satisfies 0.1mm≤L3≤20mm; And / or, the bottom width W1 of the embossing satisfies 0.1 mm≤W1≤5 mm.

4. The battery according to claim 1, characterized in that The depth H1 of each of the embossings satisfies 0.02 mm ≤ H1 ≤ 0.2 mm.

5. The battery according to claim 4, characterized in that The depth H1 of the embossing, the thickness H2 of the first packaging film, and the thickness H3 of the second packaging film satisfy 0.1≤H1 / H2≤0.5, 0.1≤H1 / H3≤0.

5.

6. The battery according to claim 5, characterized in that The thickness H2 of the first packaging film is equal to the thickness H3 of the second packaging film.

7. The battery according to claim 1, characterized in that The projection area S of a single embossing in the thickness direction of the battery satisfies 0.1 mm 2 ≤S≤100mm 2 .

8. The battery according to any one of claims 1 to 7, characterized in that The cross-sectional shape of a single embossment includes a regular shape and an irregular shape, and the regular shape includes at least one of an inverted trapezoid, a square, a circle and a triangle; When the cross section of the embossing is an inverted trapezoid, the inclination angle β of the inverted trapezoid satisfies 30°≤β≤85°.

9. A battery pack, characterized in that: include: The battery according to any one of claims 1 to 8.

10. A method for preparing a battery, characterized in that: include: Prepare a first packaging film and a second packaging film, form a receiving groove on the first packaging film, and reserve a hot melt area around the first packaging film and the second packaging film; Installing the electrode group in the receiving groove of the first packaging film; The hot melt zones of the first packaging film and the second packaging film are respectively provided with multiple rows of embossings, and the multiple rows of embossings are arranged around the electrode group. The spacing L1 of adjacent embossings in the width direction of the battery satisfies 0.1mm≤L1≤3mm, and the spacing L2 of adjacent embossings in the length direction of the battery satisfies 0.1mm≤L2≤3mm.

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