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 packaging film, a pole group, a tab and an insulating part, a containing space is formed in the packaging film, the pole group is arranged in the containing space, the tab is provided with a first connecting end and a second connecting end, the first connecting end is arranged in the containing space and electrically connected with the pole group, the second connecting end extends out of the packaging film, the thickness of the tab is t1, and t2 is a positive integer. The insulating part covers the outer surface of the tab in the width direction of the battery and is close to the first connecting end, the insulating part protrudes out of the two sides of the tab to form extension parts, the insulating part and the packaging film are in sealed connection through hot melting, the total thickness of the double-layer insulating part and the tab is t2, and t1 / t2 is larger than or equal to 0.02 and smaller than or equal to 0.5. According to the invention, the ratio of the thickness t1 of the tab to the total thickness t2 of the double-layer insulating part and the tab is within the range of 0.02 < = t1 / t2 < = 0.5, so that the connection strength of the insulating part and the packaging film after hot-melting sealing connection can be ensured, and the sealing performance and the stability of the battery are improved.

Description

Technical Field

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

[0002] Soft-pack batteries have advantages such as high specific energy, small size and light weight, so the application market of soft-pack batteries is relatively large. Soft-pack batteries mainly include pole ears, pole groups and packaging films. The packaging films encapsulate the pole groups and pole ears, and the edges of the packaging films are sealed by hot pressing.

[0003] In the prior art, an insulating member is attached to the tab of a soft-pack battery, and the insulating member and the packaging film are heat-melted to achieve a sealed connection between the tab and the packaging film. However, after the existing insulating member is heat-melted and plastic-sealed with the packaging film, there is a defect that the connection strength is relatively weak, and there is leakage during the cycle test of the soft-pack battery, resulting in 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 of leakage during the cycle test of the battery.

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

[0006] A packaging film having a containing space therein;

[0007] A pole group, arranged in the accommodation space;

[0008] 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 out of the packaging film. Along the thickness direction of the battery, the thickness of the tab is t1;

[0009] 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 t2, satisfying 0.02≤t1 / t2≤0.5.

[0010] Beneficial effect: By limiting the ratio of the thickness of the tab t1 to the total thickness of the double-layer insulation and the tab t2 within the range of 0.02≤t1 / t2≤0.5, the connection strength of the insulation and the packaging film after hot-melt sealing can be ensured. The reasonable thickness ratio enables the insulation to be better combined with the tab and the packaging film during the hot-melt plastic sealing process, effectively avoiding leakage during the use of battery cycle tests due to insufficient connection strength, and improving the sealing and stability of the battery.

[0011] When the ratio t1 / t2 is less than 0.02, the connection strength between the insulating part and the packaging film after hot-melt sealing will significantly deteriorate, causing leakage of the battery during the cycle test; when the ratio t1 / t2 is greater than 0.5, it will not only cause unnecessary waste of the tab or insulating material, but also increase the thickness of the tab or insulating part, making it more difficult to seal the insulating part and the packaging film, thereby adversely affecting the sealing between the packaging film and the insulating part.

[0012] In an optional implementation, the tab thickness t1 satisfies 0.1 mm≤t1≤5 mm.

[0013] Beneficial effect: By setting t1 within a reasonable thickness range, the tab can better cooperate with the electrode material and packaging film in the electrode group. Moderate thickness helps to form a stable and reliable connection in connection processes such as welding, ensuring the stability of current transmission. It is also beneficial to maintain a good contact state with the packaging film during the sealed connection, improve the sealing effect, and reduce the risk of leakage caused by poor contact.

[0014] If the tab is too thin (t1 is less than 0.1mm), the tab is prone to deformation, breakage and other damage during the production and assembly process of the battery (such as handling, welding and other operations) and subsequent use (such as vibration and pulling that the battery may be subjected to during charging and discharging), affecting the normal use and performance of the battery. If the thickness of the tab is too large (t1 exceeds 5mm), the amount of tab material used will increase excessively, resulting in a significant increase in battery production costs. By limiting the thickness of the tab within a certain range, the cost of the tab material can be reasonably controlled while meeting the battery performance requirements, thereby improving the market competitiveness of the product.

[0015] In an optional embodiment, the total thickness t2 of the double-layer insulating member and the pole tab satisfies 0.2 mm≤t2≤10 mm.

[0016] Beneficial effect: Within the thickness range of 0.2mm≤t2≤10mm, the insulating part 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 t2 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 t2 is less than 0.2mm, 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 implementation, along the width direction of the battery, the dimension of the extension portion is c, satisfying 4≤c / t1≤50.

[0019] Beneficial effect: In the range of 4≤c / t1≤50, it is ensured that the extension has a suitable length ratio relative to the thickness of the tab, so that a sufficiently gradual transition area is formed when the tab and the packaging film are connected through the insulating member. In this transition area, stress can be distributed more evenly to avoid stress concentration at the connection interface between the tab and the insulating member or the insulating member and the packaging film. When the battery is subjected to external force during use, this gradual transition can effectively reduce the risk of failure such as cracking and peeling caused by stress concentration at the connection part, thereby enhancing the connection reliability between the tab and the packaging film and improving the overall structural stability of the battery.

[0020] The appropriate extension length helps to form a full bond between the insulating part, the pole ear and the packaging film during the hot melt sealing process, which helps to improve the sealing performance and prevent electrolyte leakage. It can also enhance the electrical connection stability between the pole ear and the packaging film, ensure the smoothness of current transmission, reduce contact resistance, and reduce energy loss and heat generation of the battery during charging and discharging.

[0021] If the ratio of c / t1 is too large (c / t1 exceeds 50), it means that the extension is too long, which will lead to excessive use of insulating materials and increase material costs. At the same time, an overly long extension may require special mold design or processing technology to achieve precise molding, increasing the complexity and cost of the production process. On the contrary, if the ratio of c / t1 is too small (c / t1 is less than 4), an effective gradual transition effect may not be achieved, resulting in insufficient connection strength between the insulating part and the packaging film after hot melt plastic sealing. Within the range of 4≤c / t1≤50, relatively conventional materials and processes can be used to achieve a balance between cost and performance while ensuring battery performance, which is convenient for large-scale production.

[0022] In an optional embodiment, the extension portion dimension c satisfies 0.5 mm ≤ c ≤ 20 mm.

[0023] Beneficial effects: Within the length range of 0.5mm≤c≤20mm, the extension can provide a sufficient transition area for the connection between the tab and the packaging film. The transition area can better disperse the stress of the insulating part when connecting the tab and the packaging film, and avoid stress concentration in local positions such as the edge of the tab. The extension length of 0.5mm≤c≤20mm can ensure a good sealing connection between the insulating part and the packaging film to a certain extent, improve the process compatibility in the battery production process, reduce the scrap rate caused by packaging problems, and contribute to the large-scale and efficient production of batteries.

[0024] If the extension length is too long (c exceeds 20 mm), the amount of insulating parts used will increase, which will directly lead to an increase in material costs. If the extension length is too short (c is less than 0.5 mm), an effective transition effect cannot be achieved.

[0025] In an optional embodiment, there are two pole ears, and along the length direction of the battery, the two pole ears are respectively arranged on opposite sides of the packaging film, and there are two insulating members, and the two insulating members are respectively arranged corresponding to the two pole ears.

[0026] Beneficial effects: The two sets of tabs are distributed on opposite sides of the packaging film, which can make the pressure inside the battery more evenly distributed, avoiding problems such as battery bulging and deformation caused by excessive local pressure, helping to maintain the structural integrity of the battery, reduce safety risks such as internal short circuits in the battery, and improve the safety and stability of the battery.

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

[0028] Busbar;

[0029] The battery, the outer surface of the pole ear is in contact with the outer surface of the bus bar, and the pole ear and the bus bar are welded to form a weld mark.

[0030] Beneficial effects: This battery pack, including the battery as described above, has all the beneficial technical effects of the battery, which will not be repeated here. At the same time, the pole ear and the busbar are connected by welding, which provides a high-strength and stable mechanical connection, which can withstand various mechanical stresses and thermal stresses of the battery during use, prevent the pole ear and the busbar from loosening, falling off and other connection failures during use, and ensure that each battery can effectively participate in the charging and discharging process.

[0031] In an optional embodiment, along the length direction of the battery, the distance from the edge of the weld mark to the edge of the insulating member is a, satisfying 1 mm ≤ a.

[0032] Beneficial effects: During the welding process of the tab and the busbar, high temperature heat will be generated. If the weld mark is too close to the edge of the insulating part (a is less than 1mm), the insulating part will be easily affected by the high temperature and undergo property changes, such as burning, aging, deformation, etc., which will cause the adhesion between it and the tab to decrease, and even peeling. Keeping a distance of 1mm or more can effectively reduce the risk of the insulating part being burned, ensure that the insulating part can continue to stably perform its sealing and insulating functions during the use of the battery, maintain the reliability of the connection between the tab and the packaging film, and prevent problems such as electrolyte leakage and short circuit.

[0033] In an optional embodiment, along the width direction of the battery, the distance from the edge of the weld mark to the side edge of the tab is b, satisfying 0.5 mm ≤ b;

[0034] And / or, along the length direction of the battery, the distance from the edge of the weld mark to the second connecting section of the tab is f, satisfying 0.5 mm ≤ f.

[0035] Beneficial effects: When welding the tabs and busbars, high temperatures will be generated in the welding area. If the weld mark is too close to the side of the tab (b is less than 0.5mm), the edge of the tab is prone to excessive melting due to high temperature. After melting, the material at the edge of the tab may flow, shrink, and cause the edge of the tab to become irregular or even fall off, which not only affects its conductivity, but also may cause the detached metal slag to fall into the battery module, causing serious problems such as short circuits, endangering the safety and performance of the battery. Keeping b at a distance of 0.5mm or more can effectively reduce the degree to which the edge of the tab is affected by high temperature, ensuring that the tab can still maintain a good shape and performance after welding.

[0036] In an optional embodiment, along the width direction of the battery, the distance from the edge of the weld mark to the side of the busbar is E, satisfying 0.5 mm ≤ E;

[0037] And / or, along the length direction of the battery, the distance from the edge of the weld mark to the side of the busbar is F, satisfying 0.5 mm ≤ F.

[0038] Beneficial effect: During the welding process of the tab and the busbar, if the distance from the edge of the weld mark to the side of the busbar is too small (E and F are less than 0.5mm), the weld mark may exceed the range of the busbar and directly weld to the edge of the busbar. This will cause the edge of the busbar to melt and deform due to excessive heat, affecting the structural integrity and conductive performance of the busbar, and further resulting in a loose connection between the tab and the busbar, which is prone to loosening, falling off and other connection failure problems during the use of the battery, affecting the normal operation of the battery.

[0039] Keeping the distance between E and F at 0.5mm or more can provide a certain margin of error for the welding operation, reduce the risk of poor connection due to welding position deviation, ensure stable and reliable welding quality between the tab and the busbar, and ensure the stability of current transmission inside the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] 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.

[0041] Figure 1 A schematic diagram of the structure of a battery according to an embodiment of the present invention;

[0042] Figure 2 A schematic diagram of the structure of the matching of a tab and an insulating member in a battery according to an embodiment of the present invention;

[0043] Figure 3 for Figure 2 A top view of the pole lug and the insulating member shown;

[0044] Figure 4 for Figure 2 A front view of the lug and insulator shown;

[0045] Figure 5 for Figure 4 A partial enlarged schematic diagram of

[0046] Figure 6 A front view of a battery pack according to an embodiment of the invention;

[0047] Figure 7 for Figure 6 A partial enlarged schematic diagram of .

[0048] Description of reference numerals:

[0049] 1. Packaging film; 2. Pole ear; 201. First connection end; 202. Second connection end; 3. Insulating member; 301. Extension portion; 4. Bus bar; 5. Welding mark; 6. Pole group. DETAILED DESCRIPTION

[0050] 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.

[0051] In the related art, an insulating member is attached to the tab of the battery, and the insulating member and the packaging film are heat-melted to achieve a sealed connection between the tab and the packaging film. However, the existing insulating member has a relatively weak connection strength after being heat-melted and sealed with the packaging film, and leakage occurs during the battery cycle test, resulting in battery failure.

[0052] In order to solve the above technical problems, the following Figures 1 to 7 With reference to the drawings, embodiments of the present invention are described.

[0053] According to an embodiment of the present invention, on the one hand, Figures 1 to 7 As shown, a battery is provided, including a packaging film 1, a pole group, a pole ear 2 and an insulating member 3.

[0054] Specifically, Figure 1 As shown, the packaging film 1 has a containing space (not shown in the figure), and the electrode group 6 is installed in the containing space.

[0055] Specifically, combined Figures 1 to 3 As shown, the two ends of the electrode ear 2 are respectively a first connection end 201 and a second connection end 202. The first connection end 201 is arranged in the accommodation space and is electrically connected to the electrode group 6. The second connection end 202 extends outward from the packaging film 1. Figure 4 and Figure 5 As shown, along the thickness direction of the battery, the thickness of the tab 2 is t1.

[0056] Specifically, combined Figures 1 to 5 As shown, the insulating member 3 is arranged around the outer surface of the tab 2, and the insulating member 3 extends from the opposite sides of the tab 2 along the width direction of the battery to form an extension portion 301, and the tab 2 is sealed and connected by hot-melting the insulating member 3 and the packaging film 1. Along the thickness direction of the battery, the total thickness of the double-layer insulating member 3 and the tab 2 is t2, which satisfies 0.02≤t1 / t2≤0.5.

[0057] This battery can ensure the connection strength of the insulating member 3 and the packaging film 1 after hot-melt sealing by limiting the ratio of the thickness t1 of the tab 2 to the total thickness t2 of the double-layer insulating member 3 and the tab 2 within the range of 0.02≤t1 / t2≤0.5. The reasonable thickness ratio enables the insulating member 3 to be better combined with the tab 2 and the packaging film 1 during the hot-melt plastic sealing process, effectively avoiding leakage during the use of the battery cycle test due to insufficient connection strength, and improving the sealing and stability of the battery.

[0058] When the ratio t1 / t2 is less than 0.02, the connection strength between the insulating part 3 and the packaging film 1 after hot-melt sealing will significantly deteriorate, causing leakage of the battery during the cycle test; and when the ratio t1 / t2 is greater than 0.5, not only will it cause unnecessary waste of the material of the tab 2 or the insulating part 3, but also due to the increase in the thickness of the tab 2 or the insulating part 3, it will increase the difficulty of sealing the insulating part 3 and the packaging film 1, thereby adversely affecting the sealing between the packaging film 1 and the insulating part 3.

[0059] Specifically, the battery is provided with two groups of pole tabs 2, which can be respectively arranged on opposite sides of the packaging film 1, or both groups of pole tabs 2 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 2 is not specifically limited.

[0060] Specifically, combined Figure 4 and Figure 5 As shown, the thickness t1 of the tab 2 refers to the thickness t1 of the tab 2 when the tab 2 is not attached with the insulating member 3. The total thickness of the double-layer insulating member 3 and the tab 2 is t2, which can be understood as the insulating member 3 is attached to both sides of the tab 2, and the total thickness of the tab 2 and the insulating member 3 at the position where the insulating member 3 is attached is t2.

[0061] Specifically, the insulating member 3 is disposed around the pole lug 2 , which means that the insulating member 3 is attached to the front and rear surfaces and the left and right side surfaces of the pole lug 2 .

[0062] In one embodiment, Figure 4 and Figure 5 As shown, the thickness t1 of the tab 2 satisfies 0.1 mm ≤ t1 ≤ 5 mm.

[0063] By setting t1 within a reasonable thickness range, the tab 2 can better cooperate with the electrode material in the electrode group and the packaging film 1. Moderate thickness helps to form a stable and reliable connection in connection processes such as welding, ensuring the stability of current transmission, and is also conducive to maintaining a good contact state with the packaging film 1 during sealing connection, improving the sealing effect and reducing the risk of leakage caused by poor contact.

[0064] If the tab 2 is too thin (t1 is less than 0.1mm), the tab 2 is prone to deformation, breakage and other damage during the production and assembly process of the battery (such as handling, welding and other operations) and the subsequent use process (such as vibration and pulling that the battery may be subjected to during charging and discharging), affecting the normal use and performance of the battery. If the thickness of the tab 2 is too large (t1 exceeds 5mm), the amount of tab 2 material used will be excessively increased, resulting in a significant increase in the production cost of the battery. By limiting the thickness of the tab 2 within a certain range, the cost of the tab 2 material can be reasonably controlled while meeting the battery performance requirements, thereby improving the market competitiveness of the product.

[0065] In one embodiment, Figure 4 and Figure 5 As shown, the total thickness t2 of the double-layer insulating member 3 and the tab 2 satisfies 0.2 mm ≤ t2 ≤ 10 mm.

[0066] Within the thickness range of 0.2 mm ≤ t2 ≤ 10 mm, the insulating member 3 can provide a sufficient amount of material when hot-melt sealing is performed with the packaging film 1 , thereby ensuring a sealed connection between the tab 2 and the packaging film 1 and effectively preventing leakage of the electrolyte.

[0067] If the thickness of t2 exceeds 10 mm, the amount of material used in the insulating member 3 will increase significantly, resulting in a significant increase in the production cost of the battery. If the thickness of t2 is less than 0.2 mm, the insulating member 3 or the tab 2 is too thin, resulting in a relatively poor connection strength between the insulating member 3 and the packaging film 1 after hot-melt sealing.

[0068] In one embodiment, Figures 3 to 5 As shown, along the width direction of the battery, the dimension of the extension portion 301 is c, satisfying 4≤c / t1≤50.

[0069] In the range of 4≤c / t1≤50, it is ensured that the extension portion 301 has a suitable length ratio relative to the thickness of the tab 2, so that a sufficiently gradual transition area is formed when the tab 2 and the packaging film 1 are connected through the insulating member 3. In this transition area, stress can be distributed more evenly to avoid stress concentration at the connection interface between the tab 2 and the insulating member 3 or the insulating member 3 and the packaging film 1. When the battery is subjected to external force during use, this gradual transition can effectively reduce the risk of failure such as cracking and peeling caused by stress concentration at the connection part, thereby enhancing the connection reliability between the tab 2 and the packaging film 1 and improving the overall structural stability of the battery.

[0070] The appropriate length of the extension portion 301 helps to form a full bond between the insulating part 3, the pole lug 2 and the packaging film 1 during the hot melt sealing process, which helps to improve the sealing performance and prevent electrolyte leakage. It can also enhance the electrical connection stability between the pole lug 2 and the packaging film 1, ensure the smoothness of current transmission, reduce contact resistance, and reduce energy loss and heat generation of the battery during charging and discharging.

[0071] If the ratio of c / t1 is too large (c / t1 exceeds 50), it means that the extension portion 301 is too long, which will lead to excessive use of the material of the insulating part 3 and increase the material cost. At the same time, the overly long extension portion 301 may require special mold design or processing technology to achieve precise molding, increasing the complexity and cost of the production process. On the contrary, if the ratio of c / t1 is too small (c / t1 is less than 4), an effective gradual transition effect may not be achieved, resulting in insufficient connection strength between the insulating part 3 and the packaging film 1 after hot melt plastic sealing. Within the range of 4≤c / t1≤50, relatively conventional materials and processes can be used to achieve a balance between cost and performance while ensuring battery performance, which is convenient for large-scale production.

[0072] In one embodiment, Figure 3 As shown, along the width direction of the battery, the dimension c of the extension portion 301 satisfies 0.5 mm ≤ c ≤ 20 mm.

[0073] In the range of 0.5mm≤c≤20mm, the extension 301 can provide a sufficient transition area for the connection between the tab 2 and the packaging film 1. The transition area can better disperse the stress of the insulating member 3 when connecting the tab 2 and the packaging film 1, and avoid stress concentration at local positions such as the edge of the tab 2. The length of the extension 301 of 0.5mm≤c≤20mm can ensure a good sealing connection between the insulating member 3 and the packaging film 1 to a certain extent, improve the process compatibility in the battery production process, reduce the scrap rate caused by packaging problems, and contribute to the large-scale and efficient production of batteries.

[0074] If the extension portion 301 is too long (c exceeds 20 mm), the amount of insulating member 3 used will increase, which directly leads to an increase in material cost. If the extension portion 301 is too short (c is less than 0.5 mm), an effective transition effect cannot be achieved.

[0075] In one embodiment, Figure 1 As shown, there are two pole tabs 2 , which are respectively arranged on opposite sides of the packaging film 1 along the length direction of the battery, and there are two insulating members 3 , which are respectively arranged corresponding to the two pole tabs 2 .

[0076] The two tabs 2 are distributed on opposite sides of the packaging film 1, which can make the pressure inside the battery more evenly distributed, avoid battery bulging, deformation and other problems caused by excessive local pressure, help maintain the structural integrity of the battery, reduce safety risks such as internal short circuit of the battery, and improve the safety and stability of the battery.

[0077] Specifically, the two groups of pole tabs 2 can be symmetrically arranged about the axis of the packaging film 1. The symmetrical layout of the two groups of pole tabs 2 helps to reduce stress concentration, reduce the risk of failure such as breakage and peeling due to stress concentration at the connection parts between the pole tabs 2 and the pole group, and between the pole tabs 2 and the packaging film 1, and further improve the structural reliability and overall performance of the battery.

[0078] According to an embodiment of the present invention, on the other hand, Figures 1 to 7 As shown, a battery pack is also provided, comprising a bus bar 4 and batteries.

[0079] Specifically, Figure 6 and Figure 7 As shown, the outer surface of the pole lug 2 is in contact with the outer surface of the bus bar 4 , the pole lug 2 and the bus bar 4 are connected by welding, and a weld mark 5 is formed at the welding point between the pole lug 2 and the bus bar 4 .

[0080] This battery pack, including the battery as described above, has all the beneficial technical effects of the battery, which will not be described in detail here. At the same time, the pole ear 2 and the bus bar 4 are connected by welding, which provides a high-strength and stable mechanical connection, which can withstand various mechanical stresses and thermal stresses of the battery during use, prevent the pole ear 2 and the bus bar 4 from loosening, falling off, and other connection failures during use, and ensure that each battery can effectively participate in the charging and discharging process.

[0081] Specifically, the welding mark 5 can be any existing shape such as a long strip. In the embodiment of the present application, the shape of the welding mark 5 is not specifically limited.

[0082] Specifically, when the electrode tab 2 and the busbar 4 are connected, the lower surface of the electrode tab 2 may be firstly attached to the upper surface of the busbar 4 , and then the electrode tab 2 and the busbar 4 may be welded.

[0083] In one embodiment, Figure 6 and Figure 7 As shown, along the length direction of the battery, the distance from the edge of the weld mark 5 to the edge of the insulating member 3 is a, satisfying 1 mm ≤ a.

[0084] During the welding process between the tab 2 and the busbar 4, high temperature heat will be generated. If the weld mark 5 is too close to the edge of the insulating part 3 (a is less than 1mm), the insulating part 3 is easily affected by the high temperature and undergoes property changes, such as burning, aging, deformation, etc., which will cause the adhesion between it and the tab 2 to decrease, and even peeling. Keeping a distance of 1mm or more can effectively reduce the risk of the insulating part 3 being burned, ensure that the insulating part 3 can continue to stably perform its sealing and insulating functions during the use of the battery, maintain the reliability of the connection between the tab 2 and the packaging film 1, and prevent problems such as electrolyte leakage and short circuit.

[0085] In one embodiment, Figure 6 and Figure 7 As shown, the distance from the edge of the weld mark 5 to the side of the tab 2 is b, satisfying 0.5 mm ≤ b; and / or, along the length direction of the battery, the distance from the edge of the weld mark 5 to the second connection end 202 of the tab 2 is f, satisfying 0.5 mm ≤ f.

[0086] When welding the tab 2 and the busbar 4, high temperature will be generated in the welding area. If the weld mark 5 is too close to the side of the tab 2 (b or f is less than 0.5mm), the edge of the tab 2 is prone to excessive melting due to high temperature. After the material at the edge of the tab 2 melts, it may flow, shrink, and other phenomena, causing the edge of the tab 2 to become irregular or even fall off, which not only affects its conductive properties, but also may cause the detached metal slag to fall into the battery module, causing serious problems such as short circuits, endangering the safety and performance of the battery. Keeping b or f at a distance of 0.5mm or more can effectively reduce the degree to which the edge of the tab 2 is affected by high temperature, ensuring that the tab 2 can still maintain a good shape and performance after welding.

[0087] Specifically, the distance from the edge of the weld mark 5 to the side of the tab 2 is b. Figure 7 As shown, the left edge of the pole tab 2 is the left side edge, and the right edge is the right side edge. The distance from the edge of the weld mark 5 to the left side edge of the pole tab 2 is b, and the distance from the edge of the weld mark 5 to the right side edge of the pole tab 2 is also b.

[0088] In one embodiment, Figure 6 and Figure 7 As shown, along the width direction of the battery, the distance from the edge of the weld mark 5 to the side of the bus 4 is E, satisfying 0.5mm≤E; and / or, along the length direction of the battery, the distance from the edge of the weld mark 5 to the side of the bus 4 is F, satisfying 0.5mm≤F.

[0089] During the welding process of the tab 2 and the busbar 4, if the distance from the edge of the weld mark 5 to the side of the busbar 4 is too small (E and F are less than 0.5 mm), the weld mark 5 may exceed the range of the busbar 4 and directly weld to the edge of the busbar 4. This will cause the edge of the busbar 4 to melt and deform due to excessive heat, affecting the structural integrity and conductive performance of the busbar 4, and further resulting in a loose connection between the tab 2 and the busbar 4, which is prone to loosening, falling off and other connection failure problems during the use of the battery, affecting the normal operation of the battery.

[0090] Keeping the distance between E and F at 0.5 mm or more can provide a certain margin of error for the welding operation, reduce the risk of poor connection due to welding position deviation, ensure stable and reliable welding quality between the tab 2 and the busbar 4, and ensure the stability of current transmission inside the battery.

[0091] 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: 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 out of the packaging film. Along the thickness direction of the battery, the thickness of the tab is t1; 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 t2, satisfying 0.02≤t1 / t2≤0.

5.

2. The battery according to claim 1, characterized in that The tab thickness t1 satisfies 0.1 mm ≤ t1 ≤ 5 mm.

3. The battery according to claim 1, characterized in that The total thickness t2 of the double-layer insulating member and the tab satisfies 0.2 mm ≤ t2 ≤ 10 mm.

4. The battery according to claim 2, characterized in that Along the width direction of the battery, the dimension of the extension portion is c, satisfying 4≤c / t1≤50.

5. The battery according to claim 4, characterized in that The extension portion dimension c satisfies 0.5 mm ≤ c ≤ 20 mm.

6. The battery according to any one of claims 1 to 5, characterized in that There are two pole tabs, which are respectively arranged on opposite sides of the packaging film along the length direction of the battery. There are two insulating members, which are respectively arranged corresponding to the two pole tabs.

7. A battery pack, characterized in that: include: Busbar; In the battery according to any one of claims 1 to 6, the outer surface of the pole ear is in contact with the outer surface of the bus bar, and the pole ear and the bus bar are welded to form a weld mark.

8. The battery pack according to claim 7, characterized in that: Along the length direction of the battery, the distance from the edge of the weld mark to the edge of the insulating member is a, satisfying 1 mm ≤ a.

9. The battery pack according to claim 7, characterized in that: Along the width direction of the battery, the distance from the edge of the weld mark to the side edge of the tab is b, satisfying 0.5 mm ≤ b; And / or, along the length direction of the battery, the distance from the edge of the weld mark to the second connection end of the tab is f, satisfying 0.5 mm ≤ f.

10. The battery pack according to claim 7, characterized in that: Along the width direction of the battery, the distance from the edge of the weld mark to the side of the busbar is E, satisfying 0.5 mm ≤ E; And / or, along the length direction of the battery, the distance from the edge of the weld mark to the side of the busbar is F, satisfying 0.5 mm ≤ F.

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