Battery and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a battery and a battery pack, the battery comprises: a pole group provided with tabs; the first packaging film and the second packaging film are used for wrapping the pole group, the first packaging film and the second packaging film are oppositely arranged, packaging areas surrounding the pole group are arranged on the peripheries of the first packaging film and the second packaging film, and first hot melting layers are arranged on the faces, opposite to each other, of the packaging areas and the first packaging film and the second packaging film respectively; the tab is provided with an insulating layer, the insulating layer is provided with a second hot melting layer corresponding to the first hot melting layer, the tab is fixed with the first packaging film and the second packaging film through hot melting of the first hot melting layer and the second hot melting layer, a third hot melting layer is formed, and the thickness H1 of the first hot melting layer, the thickness H2 of the second hot melting layer and the thickness H3 of the third hot melting layer meet the conditions that H3 / H1 is larger than or equal to 0.3 and smaller than or equal to 0.75, and H3 / H2 is larger than or equal to 0.36 and smaller than or equal to 0.7. According to the invention, the packaging quality of the battery is improved and the material waste can be reduced by limiting the parameters of the tab and the hot melting layer of the packaging film.

Description

Technical Field

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

[0002] A battery mainly consists of pole ears, a pole group, and a packaging film. The pole group and the pole ears are encapsulated by the packaging film and sealed by hot pressing. However, when encapsulating the pole group of the existing battery, it is difficult to effectively balance the process parameters of the packaging film and the pole group. If the process parameters of hot melt encapsulation are too large, the packaging materials are likely to be wasted. If the process parameters of hot melt encapsulation are too small, the encapsulation of the battery is likely to fail. Summary of the Invention

[0003] In view of this, the present invention provides a battery and a battery pack to solve the problem that when encapsulating the pole group of the existing battery, it is difficult to effectively balance the process parameters of the packaging film and the pole group, resulting in easy failure of encapsulation and waste of packaging materials.

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

[0005] A pole group provided with pole ears;

[0006] A first packaging film and a second packaging film for wrapping outside the pole group. The first packaging film and the second packaging film are oppositely arranged and there are packaging areas surrounding the pole group on all four sides. In the packaging areas, first hot melt layers are respectively provided on the opposite sides of the first packaging film and the second packaging film;

[0007] Insulating layers are respectively provided on the opposite sides of the pole ears. The insulating layers are provided with second hot melt layers corresponding to the first hot melt layers. By hot melting the first hot melt layers and the second hot melt layers, the pole ears are respectively fixed to the first packaging film and the second packaging film, and a third hot melt layer is formed. The thickness H 1 of the first hot melt layer, the thickness H 2 of the second hot melt layer, and the thickness H 3 of the third hot melt layer satisfy 0.3 ≤ H 3 / H 1 ≤ 0.75, 0.36 ≤ H 3 / H 2 ≤ 0.7.

[0008] Beneficial effects: For the battery of the present invention, during assembly, first place the electrode group after welding the tab between the first encapsulation film and the second encapsulation film, with a part of the tab extending outside the first encapsulation film and the second encapsulation film, and perform hot-melt sealing treatment on the encapsulation area to fix the first encapsulation film and the second encapsulation film. By melting the second hot-melt layer of the insulating layer on the tab and the first hot-melt layer of the encapsulation film, a third hot-melt layer is formed to bond and fix the tab to the first encapsulation film and the second encapsulation film respectively. The structure is simple and convenient to use. By defining the proportional relationship among the first hot-melt layer, the second hot-melt layer, and the third hot-melt layer, the bonding force between the tab and the first encapsulation film and the second encapsulation film can be ensured, avoiding the tab falling off from the first encapsulation film and / or the second encapsulation film, thereby ensuring the effectiveness of the encapsulation. At the same time, materials can be saved and space utilization rate can be improved.

[0009] In an optional embodiment, the thickness H of the first hot-melt layer 1 , satisfies 0.06 mm ≤ H 1 ≤ 0.8 mm.

[0010] Beneficial effects: By defining the thickness dimension range of the first hot-melt layer, sufficient fusion between the first encapsulation film, the second encapsulation film, and the tab can be ensured. If the thickness of the first hot-melt layer is too large, the hot-melt time will be too long or the temperature will be too high, easily damaging the first encapsulation film, the second encapsulation film, and the internal electrode group. If the thickness of the first hot-melt layer is too small, it is prone to cracking.

[0011] In an optional embodiment, the thickness H of the second hot-melt layer 2 , satisfies 0.05 mm ≤ H 2 ≤ 0.3 mm.

[0012] Beneficial effects: By defining the thickness dimension range of the second hot-melt layer, the insulation between the tab and the first encapsulation film and the second encapsulation film can be ensured, preventing short circuits. If the thickness of the second hot-melt layer is too small, the hot-melt is insufficient and the bonding is not firm. If the thickness of the second hot-melt layer is too large, the hot-melt difficulty increases, affecting the production efficiency.

[0013] In an optional embodiment, the thickness H of the third hot-melt layer 3 , satisfies 0.018 mm ≤ H 3 ≤ 0.6 mm.

[0014] Beneficial effects: By defining the thickness dimension range of the third hot-melt layer, the tight bonding between the tab and the first encapsulation film and the second encapsulation film can be ensured, preventing the tab from falling off or being damaged due to the force during the charge and discharge process of the battery, and at the same time avoiding the encapsulation failure caused by too much or too little overflow of the third hot-melt layer.

[0015] In an optional embodiment, the width W of the third hot-melt layer 1, satisfying 1mm ≤ W 1 ≤ 20mm.

[0016] Advantageous effects: By defining the width dimension range of the third heat - melt layer, sufficient bonding between the tab and the first encapsulation film and the second encapsulation film can be ensured, forming a reliable sealed fixed area. If the width of the third heat - melt layer is too small, the battery expands cyclically during use, resulting in the third heat - melt layer being peeled off under stress and causing seal failure. If the width of the third heat - melt layer is too large, materials are wasted and the heat - melting difficulty increases.

[0017] In an optional implementation manner, in the length direction of the electrode group, the distance g between the outer side edge of the third heat - melt layer and the outer edge of the first encapsulation film or the second encapsulation film satisfies 0.5mm ≤ g ≤ 15mm.

[0018] Advantageous effects: If the distance g is too small, glue is likely to overflow at the outer edge of the encapsulation film during heat - melting, resulting in the third heat - melt layer being extruded and piling up to bulge. When the tab swings and pulls, the stress in the bulging and piling area is too large and is prone to cracking, thus causing the metal plate of the tab to be exposed and lapping with the aluminum foil layer of the encapsulation film, resulting in a short - circuit. If the distance g is too large, the unfastened flanges of the encapsulation film and the tab are prone to warping, and the warped parts are prone to lapping, resulting in a short - circuit.

[0019] In an optional implementation manner, the encapsulation area includes side - part encapsulation areas located on opposite sides in the width direction of the electrode group and end - part encapsulation areas located at opposite ends in the length direction of the electrode group. The opposite ends of the side - part encapsulation areas and the opposite ends of the end - part encapsulation areas cross - overlap respectively and form an overlapping area.

[0020] Advantageous effects: By arranging the ends of the side - part encapsulation area and the end - part encapsulation area to cross and form an overlapping area, it can be ensured that there is no gap at the junction of the side - part encapsulation area and the end - part encapsulation area, improving the sealing effect of the encapsulation area. Additionally, the overall strength of the encapsulation area can be improved, preventing the battery from cracking due to internal pressure changes or external forces during charge and discharge.

[0021] In an optional implementation manner, in the length direction of the electrode group, the size L of the overlapping area 1 , satisfying 0.5mm ≤ L 1 ≤ 20mm, and in the width direction of the electrode group, the size L of the overlapping area 2 , satisfying 0.5mm ≤ L 2 ≤ 20mm.

[0022] Advantageous effects: If the size of the overlapping area in the length direction and / or width direction of the electrode group is too small, the sealing performance is poor, and the battery is prone to becoming disengaged under stress during use. If the size of the overlapping area in the length direction and / or width direction of the electrode group is too large, materials and space are wasted.

[0023] In an alternative embodiment, the distance L between the end of the side encapsulation area and the edge in the length direction of the first encapsulation film or the second encapsulation film 3 satisfies 0.3 mm ≤ L 3 ≤ 20 mm;

[0024] and / or, the distance L between the end of the end encapsulation area and the edge in the width direction of the first encapsulation film or the second encapsulation film 4 satisfies 0.3 mm ≤ L 4 ≤ 20 mm.

[0025] Beneficial effects: If the distance L 3 and / or L 4 is too small, the third hot-melt layer is likely to flow out during hot pressing, resulting in glue overflow, which affects the overall size design of the battery. If the distance L 3 and / or L 4 is too large, materials and space will be wasted.

[0026] In a second aspect, the present invention also provides a battery pack, including: the above-mentioned battery.

[0027] Beneficial effects: Since the battery pack includes the battery, it has the same effects as the battery, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 is a schematic structural diagram of a battery according to an embodiment of the present invention;

[0030] Figure 2 is Figure 1 a partial enlarged view at B in

[0031] Figure 3 is Figure 1 a cross-sectional view of the battery shown in A-A;

[0032] Figure 4 is Figure 3 a partial enlarged view at C in

[0033] Figure 5 is Figure 4 a partial enlarged view at D in

[0034] Description of reference numerals:

[0035] 1. Pole group; 101. Pole ear; 2. First packaging film; 3. Second packaging film; 4. Packaging area; 401. Side packaging area; 402. End packaging area; 403. Overlapping area; 5. First hot melt layer; 6. Insulating layer; 601. Second hot melt layer; 7. Third hot melt layer. DETAILED DESCRIPTION

[0036] 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.

[0037] Combine the following Figures 1 to 5 , describing an embodiment of the present invention.

[0038] According to an embodiment of the present invention, on the one hand, a battery is provided, mainly comprising: an electrode group 1, a first packaging film 2 and a second packaging film 3. The electrode group 1 is provided with a pole ear 101. The first packaging film 2 and the second packaging film 3 are used to wrap around the electrode group 1, the first packaging film 2 and the second packaging film 3 are arranged opposite to each other and are surrounded by a packaging area 4 surrounding the electrode group 1, and in the packaging area 4, the first packaging film 2 and the second packaging film 3 are respectively provided with a first hot melt layer 5 on the opposite side.

[0039] Furthermore, the two opposite sides of the tab 101 are respectively provided with an insulating layer 6, and the insulating layer 6 is provided with a second hot-melt layer 601 corresponding to the first hot-melt layer 5. By hot-melting the first hot-melt layer 5 and the second hot-melt layer 601, the tab 101 is fixed to the first packaging film 2 and the second packaging film 3, respectively, and a third hot-melt layer 7 is formed. The thickness H of the first hot-melt layer 5 is 1 , the thickness H of the second hot melt layer 601 2 and the thickness H of the third hot melt layer 7 3 , satisfying 0.3≤H 3 / H 1 ≤0.75,0.36≤H 3 / H 2 ≤0.7.

[0040] It can be seen that for the battery provided by the embodiment of the present invention, during assembly, first place the electrode group 1 after welding the electrode tab 101 between the first encapsulation film 2 and the second encapsulation film 3. The electrode tab 101 partially extends outside the first encapsulation film 2 and the second encapsulation film 3, and perform hot-melt plastic sealing treatment on the encapsulation area 4 to fix the first encapsulation film 2 and the second encapsulation film 3. By melting the second hot-melt layer 601 of the insulating layer 6 on the electrode tab 101 and the first hot-melt layer 5 of the encapsulation film, a third hot-melt layer 7 is formed, and the electrode tab 101 is bonded and fixed to the first encapsulation film 2 and the second encapsulation film 3 respectively. The structure is simple and convenient to use. By defining the proportional relationship among the first hot-melt layer 5, the second hot-melt layer 601, and the third hot-melt layer 7, the bonding force between the electrode tab 101 and the first encapsulation film 2 and the second encapsulation film 3 can be ensured, preventing the electrode tab 101 from detaching from the first encapsulation film 2 and / or the second encapsulation film 3, thereby ensuring the effectiveness of the encapsulation. At the same time, materials can be saved and the space utilization rate can be improved.

[0041] Specifically, please refer to Figure 1 and Figure 3 , the electrode tab 101 includes a positive electrode tab and a negative electrode tab. The positive electrode tab is arranged at one end of the electrode group 1 in the length direction, the negative electrode tab is arranged at the other end of the electrode group 1 in the length direction, or the positive electrode tab and the negative electrode tab are arranged on the same side of the electrode group 1. For the length direction of the electrode group 1, please refer to the arrow L in Figure 1 , and for the width direction of the electrode group 1, please refer to the arrow W in Figure 1 . The first encapsulation film 2 and the second encapsulation film 3 are correspondingly provided with a first PP layer, and the first PP layer serves as the first hot-melt layer 5. PP is polypropylene. The insulating layer 6 can adopt electrode tab glue, and there is a second PP layer on the electrode tab glue, and the second PP layer serves as the second hot-melt layer 601. The first encapsulation film 2 and the second encapsulation film 3 are also provided with an aluminum foil layer.

[0042] It should be noted that the thickness H 3 of the third hot-melt layer 7 and the thickness H 1 of the first hot-melt layer 5, the ratio H 3 / H 1 determines the bonding force between the first PP layer and the second PP layer. If the ratio of H 3 / H 1 is less than 0.3, the melting depth of the third hot-melt layer 7 is insufficient, and the two are likely to peel off during the use of the battery, resulting in the peeling of the electrode tab 101 from the encapsulation film and ultimately leading to the failure of the encapsulation and the sealing. For example, H 3 / H 1 is 0.3, 0.4, 0.5, 0.75, etc.

[0043] In addition, if H 3 / H 2If the proportion is greater than 0.7, there will be over-melting, which affects the bonding force between the first PP layer and the aluminum foil layer. The two are prone to peeling during the use of the battery. After the battery is stressed, the peeling area expands and extends to the pole group 1. After peeling, the first PP layer has cracks or thinning areas, resulting in insufficient insulation withstand voltage strength, and ultimately leading to internal short circuit or abnormal resistance of the battery. For example, H 3 / H 2 is 0.36, 0.5, 0.6, 0.7, etc.

[0044] It should be noted that the embodiments of the present invention do not limit the specific structure of the first encapsulation film 2 and the second encapsulation film 3 wrapping the pole group 1. For example, the first encapsulation film 2 is provided with a receiving groove for installing the pole group 1, and the pole group 1 after welding the pole ear 101 is arranged in the receiving groove. Or, receiving grooves for installing the pole group 1 are respectively provided on the first encapsulation film 2 and the second encapsulation film 3. Then, the heat-melt areas around the first encapsulation film 2 and the second encapsulation film 3 are heat-melt sealed.

[0045] In one embodiment, please refer to Figure 1 , the battery can be in a rectangular structure, and the first encapsulation film 2 and the second encapsulation film 3 correspond to square sheets.

[0046] Of course, in other alternative embodiments, the battery can also be in other shapes, such as disc-shaped, elliptical cylindrical, etc. Correspondingly, the first encapsulation film 2, the second encapsulation film 3 and the pole group 1 are adaptively arranged.

[0047] It should be noted that the materials of the first encapsulation film 2 and the second encapsulation film 3 in the embodiments of the present invention can be selected according to actual situations. For example, the first encapsulation film 2 and the second encapsulation film 3 are aluminum-plastic films. The thickness of the first encapsulation film 2 and the thickness of the second encapsulation film 3 can be selected to be equal or unequal according to actual situations.

[0048] In one embodiment, please refer to Figure 4 and Figure 5 , the thickness H of the first heat-melt layer 5 1 , satisfies 0.06 mm ≤ H 1 ≤ 0.8 mm. For example, H 1 is 0.06 mm, 0.1 mm, 0.5 mm, 0.8 mm, etc. By limiting the thickness dimension range of the first heat-melt layer 5, it can ensure sufficient fusion between the first encapsulation film 2, the second encapsulation film 3 and the pole ear 101. If the thickness of the first heat-melt layer 5 is too large, the heat-melt time will be too long or the temperature will be too high, which is likely to damage the first encapsulation film 2, the second encapsulation film 3 and the internal pole group 1. If the thickness of the first heat-melt layer 5 is too small, it is prone to cracking.

[0049] Furthermore, in one embodiment, please refer to Figure 4 and Figure 5 , the thickness H of the second heat-melt layer 6012 , satisfying 0.05 mm ≤ H 2 ≤ 0.3 mm. For example, H 2 is 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, etc. By limiting the thickness dimension range of the second hot melt layer 601, the insulation between the tab 101 and the first encapsulation film 2 and the second encapsulation film 3 can be ensured, preventing short circuits. If the thickness of the second hot melt layer 601 is too small, the hot melting is insufficient and the bonding is not firm. If the thickness of the second hot melt layer 601 is too large, the hot melting difficulty increases, affecting the production efficiency.

[0050] Furthermore, in one embodiment, please refer to Figure 4 and Figure 5 , the thickness H of the third hot melt layer 7 3 , satisfying 0.018 mm ≤ H 3 ≤ 0.6 mm. For example, H 3 is 0.018 mm, 0.1 mm, 0.5 mm, 0.6 mm, etc. By limiting the thickness dimension range of the third hot melt layer 7, the tight bonding between the tab 101 and the first encapsulation film 2 and the second encapsulation film 3 can be ensured, preventing the tab 101 from falling off or being damaged due to the force during the charge and discharge process of the battery, and at the same time avoiding the encapsulation failure caused by excessive or insufficient overflow of the third hot melt layer 7.

[0051] In one embodiment, please refer to Figure 4 , the width W of the third hot melt layer 7 1 , satisfying 1 mm ≤ W 1 ≤ 20 mm. For example, W 1 is 1 mm, 2 mm, 5 mm, 20 mm, etc. By limiting the width dimension range of the third hot melt layer 7, the sufficient bonding between the tab 101 and the first encapsulation film 2 and the second encapsulation film 3 can be ensured, forming a reliable sealed fixed area. If the width of the third hot melt layer 7 is less than 1 mm, the battery expands cyclically during use, causing the third hot melt layer 7 to be peeled off by force and making the seal fail. If the width of the third hot melt layer 7 is greater than 20 mm, it will waste materials and increase the hot melting difficulty.

[0052] In one embodiment, please refer to Figure 4 and Figure 5, in the length direction of the electrode group 1, the distance g between the outer side edge of the third heat-melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 satisfies 0.5 mm ≤ g ≤ 15 mm. For example, the distance g is 0.5 mm, 1 mm, 5 mm, 15 mm, etc. The outer edges of the first encapsulation film 2 and the second encapsulation film 3 can be aligned. If the distance g is too small, it is easy for glue to overflow at the outer edge of the encapsulation film during heat melting, resulting in the extrusion and accumulation of the third heat-melt layer 7 to bulge. When the tab 101 swings and pulls, the stress in the bulging and piled-up area is too large and it is easy to crack, thus causing the metal plate of the tab 101 to be exposed and lap with the aluminum foil layer of the encapsulation film, resulting in a short circuit. If the distance g is too large, the un-fixed flanges of the encapsulation film and the tab 101 are prone to warping, and the warped parts are prone to lap, resulting in a short circuit.

[0053] In one embodiment, please refer to Figure 1 and Figure 2 , the encapsulation area 4 includes side encapsulation areas 401 located on opposite sides in the width direction of the electrode group 1 and end encapsulation areas 402 located at opposite ends in the length direction of the electrode group 1. The opposite ends of the side encapsulation areas 401 and the opposite ends of the end encapsulation areas 402 cross and overlap respectively, forming an overlapping area 403. By arranging the ends of the side encapsulation areas 401 and the end encapsulation areas 402 to cross and form the overlapping area 403, it can ensure that there is no gap at the junction of the side encapsulation areas 401 and the end encapsulation areas 402, improving the sealing effect of the encapsulation area 4. In addition, it can also improve the overall strength of the encapsulation area 4 and prevent the battery from cracking due to internal pressure changes or external forces during the charge and discharge process.

[0054] Specifically, first perform heat-melt sealing on the end encapsulation area 402, and then perform heat-melt sealing on the side encapsulation area 401.

[0055] Further, in one embodiment, please refer to Figure 2 , in the length direction of the electrode group 1, the size L of the overlapping area 403 1 satisfies 0.5 mm ≤ L 1 ≤ 20 mm, and in the width direction of the electrode group 1, the size L of the overlapping area 403 2 satisfies 0.5 mm ≤ L 2 ≤ 20 mm. For example, L 1 is 0.5 mm, 1 mm, 5 mm, 20 mm, etc., and L 2 is 0.5 mm, 1 mm, 5 mm, 20 mm, etc. If L 1 and / or L 2 is less than 0.5 mm, the sealing performance is poor, and the battery is prone to come off under stress during use. If L 1 and / or L 2 is greater than 20 mm, it wastes materials and space.

[0056] Further, in one embodiment, refer to Figure 2 , the distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 , satisfies 0.3 mm ≤ L 3 ≤ 20 mm.

[0057] And / or, the distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 , satisfies 0.3 mm ≤ L 4 ≤ 20 mm.

[0058] It should be noted that if the distance L 3 and / or L 4 is less than 0.3 mm, the third hot melt layer 7 is likely to flow and extrude during hot pressing, resulting in glue overflow, which affects the overall size design of the battery. If the distance L 3 and / or L 4 is greater than 20 mm, it wastes materials and space. For example, L 3 is 0.3 mm, 1 mm, 5 mm, 20 mm, etc., and L 4 is 0.3 mm, 1 mm, 5 mm, 20 mm, etc.

[0059] The process parameters of the battery according to the embodiments of the present invention will be further described in detail below with specific embodiments. These examples should not be construed as limiting the scope of the present invention claimed. The respective dimensional parameters of the first encapsulation film 2 and the second encapsulation film 3 in the following respective embodiments and comparative examples are kept consistent.

[0060] Embodiment 1:

[0061] The thickness H of the first hot melt layer 5 1 is 0.06 mm, the thickness H of the second hot melt layer 601 2 is 0.05 mm, and the thickness H of the third hot melt layer 7 3 is 0.018 mm, then H 3 / H 1 = 0.3, and H 3 / H 2 = 0.36. At this time, H 3 / H 1 and H 3 / H 2 are both the minimum values. The width W of the third hot melt layer 7 1 is 5 mm. The distance g between the outer edge of the third hot melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 1 mm. In the length direction of the electrode group 1, the size L of the overlapping area 403 1 is 1 mm, and in the width direction of the electrode group 1, the size L of the overlapping area 403 2is 1 mm. The distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 0.5 mm. The distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 0.5 mm. The test verification results through the battery production line are shown in Table 1.

[0062] Example 2:

[0063] The thickness H of the first hot melt layer 5 1 is 0.28 mm, the thickness H of the second hot melt layer 601 2 is 0.3 mm, the thickness H of the third hot melt layer 7 3 is 0.21 mm, then H 3 / H 1 = 0.75, H 3 / H 2 = 0.7. At this time, H 3 / H 2 is the maximum value. The width W of the third hot melt layer 7 1 is 10 mm. The distance g between the outer edge of the third hot melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 5 mm. In the length direction of the electrode group 1, the size L of the overlapping area 403 1 is 0.5 mm, and in the width direction of the electrode group 1, the size L of the overlapping area 403 2 is 0.5 mm. The distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 0.3 mm. The distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 0.3 mm.

[0064] Example 3:

[0065] The thickness H of the first hot melt layer 5 1 is 0.27 mm, the thickness H of the second hot melt layer 601 2 is 0.3 mm, the thickness H of the third hot melt layer 7 3 is 0.18 mm, then H 3 / H 1 = 0.67, H 3 / H 2 = 0.6. The width W of the third hot melt layer 7 1 is 1.2 mm. At this time, W 1 tends to the minimum value. The distance g between the outer edge of the third hot melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 5 mm. In the length direction of the electrode group 1, the size L of the overlapping area 4031 is 2 mm. In the width direction of the electrode group 1, the dimension L of the overlapping area 403 2 is 2 mm. The distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 1 mm. The distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 1 mm.

[0066] Example 4:

[0067] The thickness H of the first hot melt layer 5 1 is 0.27 mm, the thickness H of the second hot melt layer 601 2 is 0.3 mm, the thickness H of the third hot melt layer 7 3 is 0.18 mm, then H 3 / H 1 = 0.67, H 3 / H 2 = 0.6. The width W of the third hot melt layer 7 1 is 20 mm. At this time, W 1 is the maximum value. The distance g between the outer edge of the third hot melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 5 mm. In the length direction of the electrode group 1, the dimension L of the overlapping area 403 1 is 20 mm. In the width direction of the electrode group 1, the dimension L of the overlapping area 403 2 is 20 mm. The distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 20 mm. The distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 20 mm.

[0068] Example 5:

[0069] The thickness H of the first hot melt layer 5 1 is 0.3 mm, the thickness H of the second hot melt layer 601 2 is 0.3 mm, the thickness H of the third hot melt layer 7 3 is 0.18 mm, then H 3 / H 1 = 0.6, H 3 / H 2 = 0.6. The width W of the third hot melt layer 7 1 is 5 mm. The distance g between the outer edge of the third hot melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 0.5 mm. At this time, g is the minimum value. In the length direction of the electrode group 1, the dimension L of the overlapping area 403 1is 1 mm. In the width direction of the electrode group 1, the dimension L of the overlapping area 403 2 is 1 mm. The distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 0.5 mm. The distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 0.5 mm.

[0070] Example 6:

[0071] The thickness H of the first hot melt layer 5 1 is 0.3 mm, the thickness H of the second hot melt layer 601 2 is 0.3 mm, the thickness H of the third hot melt layer 7 3 is 0.18 mm, then H 3 / H 1 = 0.6, H 3 / H 2 = 0.6. The width W of the third hot melt layer 7 1 is 5 mm. The distance g between the outer edge of the third hot melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 15 mm. At this time, g is the maximum value. In the length direction of the electrode group 1, the dimension L of the overlapping area 403 1 is 10 mm. In the width direction of the electrode group 1, the dimension L of the overlapping area 403 2 is 10 mm. The distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 5 mm. The distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 5 mm.

[0072] Comparative Example 1:

[0073] The thickness H of the first hot melt layer 5 1 is 0.09 mm, the thickness H of the second hot melt layer 601 2 is 0.05 mm, the thickness H of the third hot melt layer 7 3 is 0.018 mm, then H 3 / H 1 = 0.2, H 3 / H 2 = 0.36. At this time, H 3 / H 1 is less than 0.3. The width W of the third hot melt layer 7 1 is 5 mm. The distance g between the outer edge of the third hot melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 1 mm. In the length direction of the electrode group 1, the dimension L of the overlapping area 4031 is 1 mm. In the width direction of the electrode group 1, the dimension L of the overlapping area 403 2 is 2 mm. The distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 0.5 mm. The distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 0.5 mm. The test verification results through the battery production line are shown in Table 1.

[0074] Comparative Example 2:

[0075] The thickness H of the first hot melt layer 5 1 is 0.64 mm, the thickness H of the second hot melt layer 601 2 is 0.3 mm, the thickness H of the third hot melt layer 7 3 is 0.48 mm, then H 3 / H 1 = 0.75, H 3 / H 2 = 1.6. At this time, H 3 / H 2 is greater than 0.7. The width W of the third hot melt layer 7 1 is 5 mm. The distance g between the outer edge of the third hot melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 1 mm. In the length direction of the electrode group 1, the dimension L of the overlapping area 403 1 is 2 mm. In the width direction of the electrode group 1, the dimension L of the overlapping area 403 2 is 2 mm. The distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 1 mm. The distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 1 mm. The test verification results through the battery production line are shown in Table 1.

[0076] Comparative Example 3:

[0077] The thickness H of the first hot melt layer 5 1 is 0.3 mm, the thickness H of the second hot melt layer 601 2 is 0.3 mm, the thickness H of the third hot melt layer 7 3 is 0.18 mm, then H 3 / H 1 = 0.6, H 3 / H 2 = 0.6. The width W of the third hot melt layer 7 1 is 0.8 mm. At this time, W 1Less than 1 mm. The spacing g between the outer edge of the third hot melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 10 mm. In the length direction of the electrode group 1, the size L of the overlapping area 403 1 is 10 mm. In the width direction of the electrode group 1, the size L of the overlapping area 403 2 is 10 mm. The spacing L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 5 mm. The spacing L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 5 mm.

[0078] Comparative Example 4:

[0079] The thickness H of the first hot melt layer 5 1 is 0.27 mm, the thickness H of the second hot melt layer 601 2 is 0.3 mm, the thickness H of the third hot melt layer 7 3 is 0.18 mm, then H 3 / H 1 = 0.67, H 3 / H 2 = 0.6. The width W of the third hot melt layer 7 1 is 10 mm. The spacing g between the outer edge of the third hot melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 0.4 mm. At this time, g is less than 0.5 mm. In the length direction of the electrode group 1, the size L of the overlapping area 403 1 is 5 mm. In the width direction of the electrode group 1, the size L of the overlapping area 403 2 is 5 mm. The spacing L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 5 mm. The spacing L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 5 mm.

[0080] Comparative Example 5:

[0081] The thickness H of the first hot melt layer 5 1 is 0.3 mm, the thickness H of the second hot melt layer 601 2 is 0.3 mm, the thickness H of the third hot melt layer 7 3 is 0.18 mm, then H 3 / H 1 = 0.6, H 3 / H 2 = 0.6. The width W of the third hot melt layer 7 1is 2 mm. The distance g between the outer edge of the third heat-melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 1 mm. In the length direction of the electrode group 1, the dimension L of the overlapping area 403 1 is 0.4 mm. In the width direction of the electrode group 1, the dimension L of the overlapping area 403 2 is 0.4 mm. At this time, L 1 and L 2 are both less than 0.5 mm. The distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 0.5 mm. The distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 0.5 mm.

[0082] Comparative Example 6:

[0083] The thickness H of the first heat-melt layer 5 1 is 0.3 mm, the thickness H of the second heat-melt layer 601 2 is 0.3 mm, and the thickness H of the third heat-melt layer 7 3 is 0.18 mm. Then H 3 / H 1 = 0.6, H 3 / H 2 = 0.6. The width W of the third heat-melt layer 7 1 is 2 mm. The distance g between the outer edge of the third heat-melt layer 7 and the outer edge of the first encapsulation film 2 or the second encapsulation film 3 is 1 mm. In the length direction of the electrode group 1, the dimension L of the overlapping area 403 1 is 1 mm. In the width direction of the electrode group 1, the dimension L of the overlapping area 403 2 is 1 mm. The distance L between the end of the side encapsulation area 401 and the edge in the length direction of the first encapsulation film 2 or the second encapsulation film 3 3 is 0.2 mm. The distance L between the end of the end encapsulation area 402 and the edge in the width direction of the first encapsulation film 2 or the second encapsulation film 3 4 is 0.2 mm. At this time, L 1 and L 2 are both less than 0.3 mm.

[0084] Table 1: Test results

[0085]

[0086] As can be seen from Table 1, in Examples 1 to 6, it satisfies 0.06 mm ≤ H 1 ≤ 0.8 mm, 0.05 mm ≤ H 2 ≤ 0.3 mm, 0.018 mm ≤ H 3≤0.6 mm, 0.3 ≤ H 3 / H 1 ≤0.75, 0.36 ≤ H 3 / H 2 ≤0.7, 1 mm ≤ W 1 ≤20 mm, 0.5 mm ≤ g ≤ 15 mm, 0.5 mm ≤ L 1 ≤20 mm, 0.5 mm ≤ L 2 ≤20 mm, 0.3 mm ≤ L 3 ≤20 mm, 0.3 mm ≤ L 4 ≤20 mm. Therefore, it can meet the assembly requirements of the battery and save materials.

[0087] In Comparative Example 1, H 3 / H 1 is less than 0.3, lower than the lower limit value of the embodiment of the present invention. The melting depth of the third hot melt layer 7 is insufficient, affecting the bonding force between the first PP layer and the second PP layer. During use, the first PP layer and the second PP layer are peeled off, that is, the tab 101 is peeled off from the encapsulation film, resulting in encapsulation failure.

[0088] In Comparative Example 2, H 3 / H 2 is greater than 0.7, exceeding the upper limit value of the embodiment of the present invention, overmelting occurs, affecting the bonding force between the first PP layer and the aluminum foil layer. During use, the first PP layer and the aluminum foil layer are peeled off. After the battery is stressed, the peeled area expands and extends to the pole group 1. The first PP layer after peeling shows damage or thinning areas, resulting in insufficient insulation breakdown voltage strength, and ultimately leading to internal short circuit or abnormal resistance of the battery.

[0089] In Comparative Example 3, W 1 is less than 1 mm, lower than the lower limit value of the embodiment of the present invention. During use, the battery expands cyclically, resulting in the third hot melt layer 7 being peeled off under stress, and the tab 101 falling off from the encapsulation film, resulting in encapsulation failure.

[0090] In Comparative Example 4, g is less than 0.5 mm, lower than the lower limit value of the embodiment of the present invention. During hot melting, glue overflows at the outer edge of the encapsulation film, resulting in the third hot melt layer 7 being extruded and piled up and bulging. When the tab 101 swings and pulls, the bulging and piled material area cracks, and the metal plate of the tab 101 is exposed and overlaps and shorts with the aluminum foil layer of the encapsulation film.

[0091] In Comparative Example 5, L 1 、L 2 is less than 0.5 mm, lower than the lower limit value of the embodiment of the present invention. During use, the battery is stressed and separated from the first encapsulation film 2 and the second encapsulation film 3.

[0092] In Comparative Example 6, L 3 、L 4Less than 0.3 mm, lower than the lower limit value of the embodiment of the present invention, when hot pressing, the third hot-melt layer 7 flows and extrudes, resulting in glue overflow.

[0093] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, including: a battery.

[0094] Since the battery pack includes a battery and has the same effects as the battery, they will not be described herein again.

[0095] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: The pole group is provided with pole ears; A first packaging film and a second packaging film are used to wrap around the electrode group, the first packaging film and the second packaging film are arranged opposite to each other and are surrounded by a packaging area surrounding the electrode group, and in the packaging area, a first hot melt layer is respectively provided on one side of the first packaging film and the other side of the second packaging film opposite to each other; Insulating layers are respectively provided on the opposite sides of the tab, and a second hot-melt layer is provided on the insulating layer corresponding to the first hot-melt layer. The tab is fixed to the first packaging film and the second packaging film respectively by hot-melting the first hot-melt layer and the second hot-melt layer, and a third hot-melt layer is formed. The thickness H1 of the first hot-melt layer, the thickness H2 of the second hot-melt layer and the thickness H3 of the third hot-melt layer satisfy 0.3≤H3 / H1≤0.75, and 0.36≤H3 / H2≤0.

7.

2. The battery according to claim 1, characterized in that The thickness H1 of the first hot melt layer satisfies 0.06 mm≤H1≤0.8 mm.

3. The battery according to claim 2, characterized in that The thickness H2 of the second hot melt layer satisfies 0.05 mm ≤ H2 ≤ 0.3 mm.

4. The battery according to claim 3, characterized in that The thickness H3 of the third hot melt layer satisfies 0.018 mm ≤ H3 ≤ 0.6 mm.

5. The battery according to any one of claims 1 to 4, characterized in that The width W1 of the third hot-melt layer satisfies 1mm≤W1≤20mm.

6. The battery according to any one of claims 1 to 4, characterized in that In the length direction of the electrode group, a distance g between an outer side edge of the third hot melt layer and an outer side edge of the first packaging film or the second packaging film satisfies 0.5 mm ≤ g ≤ 15 mm.

7. The battery according to any one of claims 1 to 4, characterized in that The packaging area includes side packaging areas located at opposite sides of the electrode group width direction and end packaging areas located at opposite ends of the electrode group length direction. The opposite ends of the side packaging areas cross and overlap with the opposite ends of the end packaging areas to form an overlapping area.

8. The battery according to claim 7, characterized in that In the length direction of the pole group, the dimension L1 of the overlapping area satisfies 0.5 mm ≤ L1 ≤ 20 mm, and in the width direction of the pole group, the dimension L2 of the overlapping area satisfies 0.5 mm ≤ L2 ≤ 20 mm.

9. The battery according to claim 8, characterized in that A distance L3 between the end of the side packaging area and the edge of the first packaging film or the second packaging film in the length direction satisfies 0.3 mm ≤ L3 ≤ 20 mm; And / or, a distance L4 between an end of the end packaging area and an edge of the first packaging film or the second packaging film in a width direction satisfies 0.3 mm≤L4≤20 mm.

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

Images