Battery and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a battery and a battery pack. Wherein the battery comprises a packaging film, a pole group, a pole lug and an insulating part, the pole lug is provided with a first connecting end and a second connecting end, the first connecting end is arranged in the accommodating space and is electrically connected with the pole group, the width of the pole lug is a1 along the width direction of the battery, and the insulating part is arranged around the outer surface of the pole lug; the insulating part extends out of the two opposite sides of the tab in the width direction of the battery to form extension parts, the insulating part is connected with the packaging film, and the total thickness a3 of the double-layer insulating part and the tab in the thickness direction of the battery meets the condition that a1 / a3 is greater than or equal to 0.2 and less than or equal to 200. According to the invention, the ratio of the width a1 of the tab to the total thickness a3 of the double-layer insulating part and the tab is limited within the range of 0.2 < = a1 / a3 < = 200, so that the connecting strength after the insulating part and the packaging film are connected in a hot melting and sealing manner can be ensured, the insulating part and the tab are tightly combined, the sealing effect is further enhanced, and the overall sealing property of the battery is improved.

Description

Technical Field

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

[0002] Soft-pack batteries have advantages such as high specific energy, small size, and light weight. Therefore, the application market of soft-pack batteries is relatively large. Soft-pack batteries mainly include tabs, electrode groups, and packaging films. The packaging film encapsulates the electrode group and the tabs, and seals the edge of the packaging film through hot pressing.

[0003] In the prior art, tab glue is attached to the tabs of soft-pack batteries, and the tab glue is subjected to hot melting treatment with the packaging film to achieve a sealed connection between the tabs and the packaging film. However, after the existing tab glue is hot-melt sealed with the packaging film, there is a defect that the connection strength is relatively weak, and there is a liquid leakage phenomenon during the cyclic experiment test of the soft-pack battery, resulting in the failure of the soft-pack battery. Summary of the Invention

[0004] In view of this, the present invention provides a battery and a battery pack to solve the problem that the connection strength is relatively weak after the insulating member is hot-melt sealed with the packaging film.

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

[0006] A packaging film, which is provided with an accommodation space inside;

[0007] An electrode group, which is arranged in the accommodation space;

[0008] A tab, which has a first connection end and a second connection end. The first connection end is arranged in the accommodation space and is electrically connected to the electrode group. The second connection end extends out of the packaging film. Along the width direction of the battery, the width of the tab is a1;

[0009] An insulating member, which is arranged around the outer surface of the tab. The insulating member extends out of the opposite sides of the tab along the width direction of the battery to form an extension part. The insulating member is connected to the packaging film. Along the thickness direction of the battery, the total thickness of the double-layer insulating member and the tab is a3, and 0.2 ≤ a1 / a3 ≤ 200 is satisfied.

[0010] Advantageous Effects: For this battery, by limiting the ratio of the tab width a1 to the total thickness a3 of the double-layer insulating member and the tab within the range of 0.2 ≤ a1 / a3 ≤ 200, the connection strength after the hot-melt sealing connection between the insulating member and the packaging film can be ensured, so that the insulating member is tightly combined with the tab, further enhancing the sealing effect, improving the overall sealing performance of the battery, effectively avoiding the liquid leakage situation during the use process such as the cyclic experiment test of the battery due to insufficient connection strength, and improving the sealing performance and stability of the battery.

[0011] The appropriate width can evenly disperse the stress of the tabs when subjected to various external forces (such as mechanical stress during battery assembly, expansion and contraction stress during battery charge and discharge, etc.), reduce problems such as tab damage or insulation stripping caused by local stress concentration, and thus improve the stability of the battery structure. It effectively avoids leakage during battery cycle test and other use processes due to insufficient connection strength.

[0012] When a1 / a3 is too small, the tabs may be narrow and thick, and the force dispersion is insufficient after the tabs are stressed, resulting in stress concentration. At the same time, the tabs are relatively thick, and the gap between the tab plastic sealing area and the non-tab plastic sealing area is large. The combination of the two causes the tabs and the packaging film to fail to seal. When a1 / a3 is too large, the tabs are too thin and are prone to deformation when stressed.

[0013] In an optional implementation, the width a1 of the tab satisfies 2mm≤a1≤500mm.

[0014] Beneficial effect: By limiting the width a1 of the tab within the range of 2mm≤a1≤500mm, the tab itself is guaranteed to have sufficient structural strength. Too narrow tabs are easily damaged by external forces during battery assembly, transportation and use, such as breaking, bending and deformation, and this can be effectively avoided within the range.

[0015] In an optional implementation, the total thickness a3 of the double-layer insulating member and the pole tab satisfies 0.3 mm ≤ a3 ≤ 10 mm.

[0016] Beneficial effect: Within the thickness range of 0.3mm≤a3≤10mm, the insulating member can provide a sufficient amount of material when hot-melt sealing is performed with the packaging film, ensuring a sealed connection between the tab and the packaging film, thereby effectively preventing leakage of the electrolyte.

[0017] If the thickness of a3 exceeds 10mm, the amount of insulating material used will increase significantly, resulting in a significant increase in the cost of battery production. If the thickness of a3 is less than 0.3mm, the insulating part or the tab is too thin, resulting in relatively poor connection strength between the insulating part and the packaging film after hot-melt sealing.

[0018] In an optional embodiment, along the width direction of the battery, inclined surfaces are formed on the first wall and the second wall of the pole lug on opposite sides thereof, and the thickness of the pole lug at the inclined surfaces gradually decreases from the center of the pole lug to both sides of the pole lug, and the insulating member is fitted on the inclined surfaces to form a transition portion.

[0019] Beneficial effects: The setting of the inclined surface makes the thickness of the pole ear gradually shrink at the edge, forming a gradient structure. When the insulating part is attached to the inclined surface to form a transition part, the transition of the insulating part from the edge of the pole ear to the center is more natural and smooth. During hot melt plastic sealing, the insulating part can better integrate with the packaging film, which helps to form a more uniform and reliable sealing connection, improve the sealing performance of the battery, and effectively prevent electrolyte leakage. It avoids the problem of poor sealing caused by sudden thickness changes.

[0020] The design of the inclined surface can change the distribution of stress on the tab. Since the thickness of the tab gradually changes at the inclined surface, the stress can be dispersed more evenly along the inclined surface instead of being concentrated at a certain point or area on the edge of the tab. This can effectively reduce the damage to the tab caused by stress concentration, thereby improving the stability of the connection structure between the tab and the packaging film and extending the service life of the battery.

[0021] In an optional embodiment, the angle between the extension portion and the transition portion is y, and when 0.3mm≤a3<3mm, 95°≤y≤175° is satisfied; and / or, when 3mm≤a3<8mm, 110°≤y≤160° is satisfied; and / or, when 8mm≤a3≤10mm, 130°≤y≤145° is satisfied.

[0022] Beneficial effect: According to different sizes of a3, a corresponding angle y is set between the extension part and the transition part, which can make the tab plastic sealing area and the non-tab plastic sealing area transition evenly, so as to ensure the sealing effect of the corresponding area of ​​the transition part and reduce the easy peeling and falling of the packaging film due to the large height difference between the tab plastic sealing area and the non-tab plastic sealing area.

[0023] In an optional embodiment, along the thickness direction of the battery, the thickness of the pole ear is t1, and the angle between the extension portion and the inclined surface is x, and when 0.1≤t1<3mm, 93°≤x≤175° is satisfied; and / or, when 3mm≤t1<8mm, 115°≤x≤160° is satisfied; and / or, when 8mm≤t1≤10mm, 135°≤x≤145° is satisfied.

[0024] Beneficial effect: When 0.1≤t1≤3mm, the angle range of 93°≤x≤175° ensures that when the tab is thin, the connection angle between the extension and the inclined surface is conducive to the sealing of the insulating part at the end of the tab. When the thinner tab is subjected to force during the use of the battery, if the angle is not appropriate, the sealing of the end of the insulating part is poor, and electrolyte leakage is prone to occur. Within this angle range, the insulating part can better fit the end of the tab, forming an effective seal after hot melt plastic sealing, preventing the electrolyte from leaking from the end of the tab, and improving the sealing performance of the battery.

[0025] When 3mm ≤ t1 < 8mm, the included angle range of 115° ≤ x ≤ 160° is adapted to the thick tab. As the tab thickness increases, the included angle needs to be adjusted to adapt to the structural changes of the tab, ensuring the sealing effect between the insulating part at the tab end and its extended part and the encapsulation film. The appropriate angle can enable the insulating part to form a continuous and tight sealing layer at the tab end, enhancing the sealing reliability of the battery at this tab thickness and reducing the risk of liquid leakage caused by poor sealing.

[0026] When 8mm ≤ t1 ≤ 10mm, the included angle range of 135° ≤ x ≤ 145° is further optimized for sealing the thicker tab. The thicker tab has higher sealing requirements for the insulating part. This angle range can enable the insulating part to form a stable sealing structure between the tab end and its extended part, effectively preventing the leakage of electrolyte at the tab end, ensuring the sealing performance of the battery during use, maintaining the stability of the internal chemical environment of the battery, and guaranteeing the normal operation of the battery.

[0027] In an alternative embodiment, along the thickness direction of the battery, the thickness of the insulating part located on the first wall surface of the tab is h1, satisfying 0.05mm ≤ h1 ≤ 10mm.

[0028] Beneficial effects: When 0.05mm ≤ h1 ≤ 10mm, it ensures that there is sufficient adhesion between the insulating part, the tab, and the encapsulation film. The insulating part plays a key role in connecting the tab and the encapsulation film in the battery. If the thickness is too small, the adhesion is insufficient, and during the use of the battery, especially when affected by vibration, temperature changes, etc., the insulating part is likely to separate from the tab or the encapsulation film, resulting in sealing failure and further causing problems such as electrolyte leakage, affecting the normal use and lifespan of the battery. If the thickness is too large, it will lead to an increase in material cost, an increase in battery weight, and a certain impact on the battery energy density.

[0029] In an alternative embodiment, along the length direction of the battery, the width of the insulating part is L, satisfying 2mm ≤ L ≤ 50mm.

[0030] Beneficial effects: When 2mm ≤ L ≤ 50mm, it can better wrap the tab, enhance the adhesion, and ensure the formation of a continuous and stable sealing area at the connection part between the tab and the encapsulation film. The sufficient width can effectively prevent external impurities such as moisture and oxygen from entering the battery interior, while preventing the electrolyte from leaking out, maintaining the stability of the internal chemical environment of the battery, and guaranteeing the normal operation of the battery.

[0031] If the width of the insulating part is too narrow, the contact area between it and the tab and the encapsulation film is insufficient, and the bonding force will be affected. During the use of the battery, the insulating part is likely to separate from the tab or the encapsulation film, resulting in seal failure, and further causing problems such as electrolyte leakage, which affects the battery performance and life. If the width of the insulating part is too large, exceeding the actual required range, it will not only increase the material cost, but also occupy more space inside the battery, which has an adverse effect on the energy density of the battery.

[0032] In an alternative embodiment, along the thickness direction of the battery, the thickness of the extension part of the double-layer insulating part is t3, satisfying 0.1mm ≤ t3 ≤ 4mm.

[0033] Beneficial effects: When 0.1mm ≤ t3 ≤ 4mm, it ensures that the extension parts of the insulating part on both sides of the tab have a certain thickness. The sufficient thickness can make the insulating part better fill and shape at the steps on both sides of the tab, ensuring that it can be closely attached to the encapsulation film after hot melting, forming a continuous and effective seal, preventing electrolyte leakage from both sides of the tab, and improving the sealing performance of the battery.

[0034] If t3 is too thick, exceeding 4mm, the transition at the steps on both sides of the tab will be uneven during hot-melt encapsulation. The too-thick insulating part may not be evenly heated and flow during the hot-melt process, resulting in an uneven sealing layer on both sides of the tab, and even defects such as bubbles and wrinkles may be generated, seriously affecting the sealing effect and making the battery prone to liquid leakage.

[0035] In a second aspect, the present invention also provides a battery pack, including a battery.

[0036] Beneficial effects: This battery pack, including the battery as described above, has all the beneficial technical effects of this battery, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] 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 following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0038] Figure 1 A front view of a battery according to an embodiment of the present invention;

[0039] Figure 2 A structural schematic diagram of a tab and an insulating part in a battery according to an embodiment of the present invention;

[0040] Figure 3 For Figure 2 The front view of the tab and the insulating part shown;

[0041] Figure 4 is Figure 2 the side view of the tab and the insulating member shown;

[0042] Figure 5 is Figure 4 the partial enlarged schematic view of

[0043] Description of the reference numerals in the drawings:

[0044] 1. Encapsulation film; 2. Electrode group; 3. Tab; 301. First connection end; 302. Second connection end; 304. First wall surface; 305. Second wall surface; 306. Inclined surface; 4. Insulating member; 401. Extension part; 402. Transition part. Detailed implementation manners

[0045] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0046] In the related art, a tab glue is attached to the tab of a soft-pack battery, and a heat melting treatment is performed on the tab glue and the encapsulation film to achieve a sealed connection between the tab and the encapsulation film. However, after the existing tab glue is heat-melted and sealed with the encapsulation film, there is a defect that the connection strength is relatively weak, and there is a liquid leakage phenomenon during the cyclic experiment test of the soft-pack battery, resulting in the failure of the soft-pack battery.

[0047] To solve the above technical problems, the embodiments of the present invention will be described below in conjunction with Figures 1 to 5 ,

[0048] According to an embodiment of the present invention, on the one hand, as Figures 1 to 5 shown, a battery is provided, including an encapsulation film 1, an electrode group 2, a tab 3 and an insulating member 4.

[0049] Specifically, as Figure 1 shown, an accommodation space (not shown in the figure) is provided inside the encapsulation film 1.

[0050] Specifically, as Figure 1 shown, the electrode group 2 is installed in the accommodation space.

[0051] Specifically, as Figures 1 to 3As shown, the tab 3 has a first connection end 301 and a second connection end 302. The first connection end 301 is installed in the accommodation space and electrically connected to the electrode group 2, and the second connection end 302 extends out of the packaging film 1. Along the width direction of the battery, the width of the tab 3 is a1.

[0052] Specifically, Figures 1 to 3 As shown, the insulating member 4 is arranged around the outer surface of the tab 3, and the insulating member 4 extends out of the opposite sides of the tab 3 along the width direction of the battery to form an extension portion 401. The insulating member 4 is sealed and connected to the packaging film 1. Along the thickness direction of the battery, the total thickness of the double-layer insulating member 4 and the tab 3 is a3, which satisfies 0.2≤a1 / a3≤200.

[0053] This battery, by limiting the ratio of the width a1 of the pole tab 3 to the total thickness a3 of the double-layer insulating member 4 and the pole tab 3 within the range of 0.2≤a1 / a3≤200, can ensure the connection strength of the insulating member 4 and the packaging film 1 after hot-melt sealing, so that the insulating member 4 and the pole tab 3 are tightly combined, further enhancing the sealing effect, improving the overall sealing of the battery, and effectively avoiding leakage during use such as battery cycle experiments due to insufficient connection strength, thereby improving the sealing and stability of the battery.

[0054] The appropriate width can evenly disperse the stress of the tab 3 when it is subjected to various external forces (such as mechanical stress during battery assembly, expansion and contraction stress during battery charge and discharge, etc.), reduce the damage of the tab 3 or the peeling of the insulating member 4 caused by local stress concentration, and thus improve the stability of the battery structure. It effectively avoids leakage during battery cycle test and other use due to insufficient connection strength.

[0055] When a1 / a3 is too small, the tab 3 may be narrow and thick, and the force dispersion of the tab 3 is insufficient after the tab 3 is subjected to force, resulting in stress concentration. At the same time, the tab 3 is relatively thick, and the gap between the tab plastic sealing area and the non-tab plastic sealing area is large. The combination of the two causes the tab 3 and the packaging film 1 to fail to seal. When a1 / a3 is too large, the tab 3 is too thin, and it is easy to deform when the tab 3 is subjected to force.

[0056] Specifically, the battery is provided with two groups of pole tabs 3, which can be respectively arranged on opposite sides of the packaging film 1, or both groups of pole tabs 3 can be arranged on the same side of the packaging film 1. In the embodiment of the present application, the position of the pole tabs 3 is not specifically limited.

[0057] Specifically, combined Figure 4 and Figure 5 As shown, the total thickness of the double-layer insulating member 4 and the pole lug 3 is a3. It can be understood that the insulating member 4 is pasted on both opposite sides of the pole lug 3, and the total thickness of the pole lug 3 and the insulating member 4 at the position where the insulating member 4 is pasted is a3.

[0058] Specifically, the insulating member 4 surrounding the tab 3 means that the insulating member 4 is attached to the front and back surfaces and the left and right side surfaces of the tab 3.

[0059] It should be noted that the insulating member 4 in this embodiment can be tab glue.

[0060] In one embodiment, as Figure 3 shown, the width a1 of the tab 3 satisfies 2 mm ≤ a1 ≤ 500 mm.

[0061] By limiting the width a1 of the tab 3 within the range of 2 mm ≤ a1 ≤ 500 mm, it is ensured that the tab 3 itself has sufficient structural strength. A tab 3 that is too narrow is prone to being damaged by external forces such as breaking or bending deformation during battery assembly, handling, and use, while this situation can be effectively avoided within this range.

[0062] In one embodiment, as Figure 5 shown, the total thickness a3 of the double - layer insulating member 4 and the tab 3 satisfies 0.3 mm ≤ a3 ≤ 10 mm.

[0063] Within the thickness range of 0.3 mm ≤ a3 ≤ 10 mm, the insulating member 4 can provide a sufficient amount of material when heat - melt sealing with the encapsulation film 1, ensuring a sealed connection between the tab 3 and the encapsulation film 1 and effectively preventing electrolyte leakage.

[0064] If the thickness a3 exceeds 10 mm, the amount of insulating member 4 material will increase significantly, resulting in a significant increase in battery production cost. If the thickness a3 is less than 0.3 mm, the insulating member 4 or the tab 3 is too thin, resulting in relatively poor connection strength after heat - melt sealing between the insulating member 4 and the encapsulation film 1.

[0065] In one embodiment, as Figure 5 shown, the first wall surface 304 and the second wall surface 305 of the tab 3 are both provided with inclined surfaces 306, and the inclined surfaces 306 are arranged on both sides close to the tab 3 along the width direction of the battery. From the center of the tab 3 to both sides of the tab 3, the thickness of the tab 3 at the inclined surface 306 gradually decreases, and the insulating member 4 fits on the inclined surface 306 to form a transition portion 402.

[0066] The setting of the inclined surface 306 causes the thickness of the tab 3 to gradually contract at the edge, forming a gradient structure. When the insulating member 4 fits on the inclined surface 306 to form the transition portion 402, the transition of the insulating member 4 from the edge to the center of the tab 3 is more natural and smooth. During heat - melt plastic sealing, the insulating member 4 can better fuse with the encapsulation film 1, contributing to forming a more uniform and reliable sealed connection, improving the sealing performance of the battery, and effectively preventing electrolyte leakage. It avoids the problem of poor sealing that may be caused by sudden thickness changes.

[0067] The design of the inclined surface 306 can change the distribution of stress on the pole lug 3. Since the thickness of the pole lug 3 gradually changes at the inclined surface 306, the stress can be more evenly dispersed along the inclined surface 306 instead of being concentrated at a certain point or area on the edge of the pole lug 3. This can effectively reduce the damage to the pole lug 3 caused by stress concentration, thereby improving the stability of the connection structure between the pole lug 3 and the packaging film 1 and extending the service life of the battery.

[0068] In one embodiment, the angle between the extension portion 401 and the transition portion 402 is y, and when 0.3 mm ≤ a3 < 3 mm, 95° ≤ y ≤ 175° is satisfied. And / or, when 3 mm ≤ a3 < 8 mm, 110° ≤ y ≤ 160° is satisfied. And / or, when 8 mm ≤ a3 ≤ 10 mm, 130° ≤ y ≤ 145° is satisfied.

[0069] According to the different sizes of a3, a corresponding angle y is set between the extension part 401 and the transition part 402, so that the tab plastic sealing area and the non-tab plastic sealing area can be uniformly transitioned, thereby ensuring the sealing effect of the corresponding area of ​​the transition part 402 and reducing the packaging film 1 from being easily peeled off due to the large height difference between the tab plastic sealing area and the non-tab plastic sealing area. Figure 5 As shown, along the thickness direction of the battery, the thickness of the tab 3 is t1, and the angle between the extension portion 401 and the inclined surface 306 is x. When 0.1≤t1<3mm, 93°≤x≤175° is satisfied. And / or, when 3mm≤t1<8mm, 115°≤x≤160° is satisfied. And / or, when 8mm≤t1≤10mm, 135°≤x≤145° is satisfied.

[0070] When 0.1≤t1<3mm, the angle range of 93°≤x≤175° ensures that when the tab 3 is thin, the connection angle between the extension 401 and the inclined surface 306 is conducive to the sealing of the insulating member 4 at the end of the tab 3. When the thinner tab 3 is subjected to force during the use of the battery, if the angle is not appropriate, the sealing of the end of the insulating member 4 is poor, and electrolyte leakage is likely to occur. Within this angle range, the insulating member 4 can better fit the end of the tab 3, form an effective seal after hot melt plastic sealing, prevent the electrolyte from leaking from the end of the tab 3, and improve the sealing performance of the battery.

[0071] When 3mm≤t1<8mm, the angle range of 115°≤x≤160° is compatible with the thickness of the tab 3. As the thickness of the tab 3 increases, the angle needs to be adjusted to adapt to the structural changes of the tab 3 to ensure the sealing effect between the insulating member 4 at the end of the tab 3 and the extension 401 and the packaging film 1. The appropriate angle can enable the insulating member 4 to form a continuous and tight sealing layer at the end of the tab 3, enhance the sealing reliability of the battery at the thickness of the tab 3, and reduce the risk of leakage caused by poor sealing.

[0072] When 8mm ≤ t1 ≤ 10mm, the angle range limit of 135° ≤ x ≤ 145° further optimizes the sealing for the relatively thick tab 3. The relatively thick tab 3 has higher sealing requirements for the insulating part 4. This angle range can enable the insulating part 4 to form a stable sealing structure between the end of the tab 3 and the extension part 401, effectively preventing the leakage of electrolyte at the end of the tab 3, ensuring the sealing performance of the battery during use, maintaining the stability of the internal chemical environment of the battery, and guaranteeing the normal operation of the battery.

[0073] In one embodiment, as Figure 5 shown, along the thickness direction of the battery, the thickness of the insulating part 4 on the first wall surface 304 of the tab 3 is h1 (the thickness of a single-layer insulating part 4), satisfying 0.05mm ≤ h1 ≤ 10mm.

[0074] When 0.05mm ≤ h1 ≤ 10mm, it ensures that there is sufficient adhesion between the insulating part 4, the tab 3, and the encapsulation film 1. The insulating part 4 plays a key role in connecting the tab 3 and the encapsulation film 1 in the battery. If the thickness is too small, the adhesion is insufficient, and during the use of the battery, especially when affected by vibration, temperature changes, etc., the insulating part 4 is likely to separate from the tab 3 or the encapsulation film 1, resulting in sealing failure and further causing problems such as electrolyte leakage, affecting the normal use and life of the battery. If the thickness is too large, it will lead to an increase in material cost, an increase in the weight of the battery, and have a certain impact on the energy density of the battery.

[0075] In one embodiment, as Figure 3 shown, along the length direction of the battery, the width of the insulating part 4 is L, satisfying 2mm ≤ L ≤ 50mm.

[0076] When 2mm ≤ L ≤ 50mm, it can better wrap the tab 3, enhance the adhesion, and ensure the formation of a continuous and stable sealing area at the connection part between the tab 3 and the encapsulation film 1. Sufficient width can effectively prevent external impurities such as moisture and oxygen from entering the battery interior, while preventing the leakage of electrolyte, maintaining the stability of the internal chemical environment of the battery, and guaranteeing the normal operation of the battery.

[0077] If the width of the insulating part 4 is too narrow, the contact area between it and the tab 3 and the encapsulation film 1 is insufficient, and the adhesion will be affected. During the use of the battery, the insulating part 4 is likely to separate from the tab 3 or the encapsulation film 1, resulting in sealing failure and further causing problems such as electrolyte leakage, affecting the battery performance and life. If the width of the insulating part 4 is too large, beyond the actual required range, it will not only increase the material cost but also occupy more space inside the battery, having an adverse impact on the energy density of the battery.

[0078] In one embodiment, as Figure 5As shown, along the thickness direction of the battery, the thickness of the extension portion 401 of the double-layer insulating member 4 is t3, satisfying 0.1 mm ≤ t3 ≤ 4 mm.

[0079] When 0.1 mm ≤ t3 ≤ 4 mm, it ensures that the extension portions 401 of the insulating member 4 on both sides of the tab 3 have a certain thickness. The sufficient thickness enables the insulating member 4 to better fill and shape at the steps on both sides of the tab 3, ensuring that it can closely adhere to the encapsulation film 1 after hot melting, forming a continuous and effective seal, preventing the electrolyte from leaking from both sides of the tab 3, and improving the sealing performance of the battery.

[0080] If t3 is too thick, exceeding 4 mm, the transition at the steps on both sides of the tab 3 during hot melting and encapsulation will be uneven. The too-thick insulating member 4 may not be evenly heated and flow during the hot melting process, resulting in an uneven sealing layer on both sides of the tab 3, and even defects such as bubbles and wrinkles may occur, seriously affecting the sealing effect and making the battery prone to liquid leakage.

[0081] Specifically, the thickness of the extension portion 401 refers to the thickness of the double-layer insulating member 4.

[0082] According to an embodiment of the present invention, on the other hand, a battery pack including a battery is also provided.

[0083] This battery pack includes the battery as described above and has all the beneficial technical effects of the battery, which will not be elaborated here.

[0084] To better illustrate the quality of the battery pack, the following experimental test is taken as an example:

[0085]

[0086]

[0087]

[0088]

[0089] 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: A packaging film having a containing space therein; A pole group, arranged in the accommodation space; A tab having a first connection end and a second connection end, wherein the first connection end is disposed in the accommodation space and electrically connected to the tab group, and the second connection end extends outward from the packaging film, and along the width direction of the battery, the width of the tab is a1; An insulating member is arranged around the outer surface of the pole ear, and the insulating member extends from the opposite sides of the pole ear along the width direction of the battery to form an extension portion. The insulating member is connected to the packaging film, and along the thickness direction of the battery, the total thickness of the double-layer insulating member and the pole ear is a3, satisfying 0.2≤a1 / a3≤200.

2. The battery according to claim 1, characterized in that The width a1 of the tab satisfies 2mm≤a1≤500mm.

3. The battery according to claim 2, characterized in that The total thickness a3 of the double-layer insulating member and the pole ear satisfies 0.3mm≤a3≤10mm.

4. The battery according to claim 3, characterized in that Along the width direction of the battery, the opposite sides of the pole lug are provided with inclined surfaces on the first wall surface and the second wall surface of the pole lug. From the center of the pole lug to the two sides of the pole lug, the thickness of the pole lug at the inclined surface gradually decreases, and the insulating member is fitted at the inclined surface to form a transition portion.

5. The battery according to claim 4, characterized in that The angle y between the extension portion and the transition portion satisfies 95°≤y≤175° when 0.3mm≤a3<3mm; and / or, when 3mm≤a3<8mm, satisfies 110°≤y≤160°; and / or, when 8mm≤a3≤10mm, satisfies 130°≤y≤145°.

6. The battery according to claim 4, characterized in that Along the thickness direction of the battery, the thickness of the tab is t1, and the angle between the extension portion and the inclined surface is x. When 0.1≤t1<3mm, 93°≤x≤175° is satisfied; and / or, when 3mm≤t1<8mm, 115°≤x≤160° is satisfied; and / or, when 8mm≤t1≤10mm, 135°≤x≤145° is satisfied.

7. The battery according to claim 4, characterized in that Along the thickness direction of the battery, the thickness of the insulating member is h1, satisfying 0.05mm≤h1≤10mm.

8. The battery according to any one of claims 1 to 7, characterized in that Along the length direction of the battery, the width of the insulating member is L, satisfying 2mm≤L≤50mm.

9. The battery according to any one of claims 1 to 7, characterized in that Along the thickness direction of the battery, the thickness of the extension portion is t3, satisfying 0.1 mm≤t3≤4 mm.

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

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