Pouch cell

Abstract

The utility model provides a kind of soft package battery, the soft package battery includes electric core, tab and electrode output piece, tab includes positive tab and negative tab, along first direction, positive tab and negative tab are respectively led out from the opposite ends of electric core;Electrode output piece, including positive electrode sheet and negative electrode sheet, positive electrode sheet and negative electrode sheet are respectively connected in the side of positive tab and negative tab away from electric core, and along first direction, positive electrode sheet and positive tab at least partially overlap, negative electrode sheet and negative tab at least partially overlap, the overlapping direction of positive electrode sheet and positive tab and the overlapping direction of negative electrode sheet and negative tab are same, the soft package battery can reduce the situation that tab is disconnected with pole when being subjected to vibration.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a soft-pack battery. Background Technology

[0002] In related technologies, the connection between the terminal and the tab of a pouch battery is relatively soft. When the pouch battery is subjected to vibration or other conditions, the connection between the terminal and the tab is prone to twisting or tearing, which can lead to the tab and the terminal breaking apart. Utility Model Content

[0003] In view of the above-mentioned technical problems, the present invention provides a soft-pack battery to reduce the situation where the tabs and terminals of the soft-pack battery break off when subjected to vibration, so as to at least partially solve the above-mentioned technical problems.

[0004] This utility model provides a soft-pack battery, comprising: a battery cell; tabs, including a positive tab and a negative tab, which are respectively led out from opposite ends of the battery cell along a first direction; and an electrode output component, including a positive electrode plate and a negative electrode plate, which are respectively connected to the positive tab and the negative tab on the side away from the battery cell, and along the first direction, the positive electrode plate and the positive tab at least partially overlap, and the negative electrode plate and the negative tab at least partially overlap, and the overlap direction of the positive electrode plate and the positive tab is the same as the overlap direction of the negative electrode plate and the negative tab.

[0005] Through the above technical solution, namely the soft-pack battery provided by this utility model, since the electrode output component is usually part of the terminal post of the soft-pack battery, in the length direction of the soft-pack battery, the positive electrode plate and the negative electrode plate of the soft-pack battery are both connected to the same side of the positive and negative electrode tabs. When the soft-pack battery is vibrated, the positive electrode plate and the negative electrode plate located on the same side will be subjected to the same torsional direction and the same external force. That is, when the positive electrode plate and the negative electrode plate are vibrated, they both twist in the same direction, so as to reduce the tearing caused by the different torsional directions of the positive electrode plate and the negative electrode plate, thereby reducing the situation where the electrode plate and the tab tear and break. Attached Figure Description

[0006] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0007] Figure 1This is a schematic diagram of the overall structure of the soft-pack battery provided in an exemplary embodiment of the present utility model; Figure 2 This is a front view of the soft-pack battery and its internal structure provided in an exemplary embodiment of the present utility model; Figure 3 for Figure 2 A magnified view of a portion of position A in the middle; Figure 4 This is a top view of the soft-pack battery and its internal structure provided in an exemplary embodiment of the present utility model; Figure 5 for Figure 4 A magnified view of a portion of position B in the middle; Figure 6 for Figure 4 A magnified view of the area at position C.

[0008] Explanation of reference numerals in the attached figures: 1. Battery cell; 2. Tab; 201. Dispersion section; 202. Gathering section; 210. Positive tab; 211. First solder mark; 220. Negative tab; 221. Second solder mark; 3. Electrode output component; 31. Positive electrode plate; 32. Negative electrode plate; 4. Housing; 410. First outlet hole; 420. Second outlet hole; 430. First seal; 440. Second seal; 5. First reference plane. Detailed Implementation

[0009] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0010] In related technologies, the connection between the terminal and the tab of a pouch battery is relatively soft. When the pouch battery is subjected to vibration or other conditions, the connection between the terminal and the tab is prone to twisting and tearing, which can lead to the tab and the terminal breaking apart.

[0011] Based on the above-mentioned technical problems, this utility model provides a soft-pack battery, as shown in the reference. Figures 1 to 6As shown, the pouch battery includes a cell 1, tabs 2, and an electrode output component 3. The tabs 2 include a positive tab 210 and a negative tab 220. Along a first direction, the positive tab 210 and the negative tab 220 are led out from opposite ends of the cell 1. The electrode output component 3 includes a positive electrode plate 31 and a negative electrode plate 32. The positive electrode plate 31 and the negative electrode plate 32 are respectively connected to the side of the positive tab 210 and the negative tab 220 away from the cell 1. Along the first direction, the positive electrode plate 31 and the positive tab 210 overlap at least partially, and the negative electrode plate 32 and the negative tab 220 overlap at least partially. The overlap direction of the positive electrode plate 31 and the positive tab 210 is the same as the overlap direction of the negative electrode plate 32 and the negative tab 220.

[0012] In the above-described manner, i.e., the soft-pack battery provided by this utility model, since the electrode output component 3 is usually part of the terminal post of the soft-pack battery, in the length direction of the soft-pack battery, the positive electrode 31 and the negative electrode 32 of the soft-pack battery are both connected to the same side of the positive electrode tab 210 and the negative electrode tab 220. When the soft-pack battery is vibrated, the positive electrode 31 and the negative electrode 32 located on the same side will be subjected to the same direction of torsion and the same magnitude of external force. That is, when the positive electrode 31 and the negative electrode 32 are vibrated, they will both torsion in the same direction, so as to reduce the tearing caused by the different torsion directions of the positive electrode 31 and the negative electrode 32, thereby reducing the situation where the electrode 3 and the tab 2 tear and break.

[0013] It should be noted that the first direction mentioned in the above embodiments can be... Figures 2 to 6 In the diagram, the direction pointed to by the arrow X in any of the attached images is the same below.

[0014] It can be understood that a pouch battery can typically make contact with external conductive elements through the aforementioned positive electrode plate 31 and negative electrode plate 32 to achieve current output or output. When the pouch battery vibrates, the positive electrode plate 210, positive electrode plate 31, negative electrode plate 32, and negative electrode plate 220 can all twist in the same direction, that is, they can simultaneously make slight clockwise or counterclockwise twists around the length direction of the pouch battery. This reduces the pulling or tearing caused by the different twisting directions of the positive electrode plate 31 and negative electrode plate 32, thereby improving the service life of the pouch battery.

[0015] Furthermore, the thickness direction of cell 1 mentioned in the following embodiments can be understood as... Figures 2 to 6The direction pointed to by the Z arrow in any of the attached figures is the same as the thickness direction of the cell 1 mentioned below. To avoid ambiguity in the following embodiments, the direction pointed to by the X arrow can be understood as the lead-out direction of the tab 2 or the length direction of the cell 1, that is, the first direction mentioned above. The direction pointed to by the Y arrow can be the width direction of the tab 2.

[0016] To facilitate understanding of the specific structure of the soft-pack battery of this utility model by those skilled in the art, the specific structure of the battery is described in this embodiment as follows.

[0017] A battery cell is the basic unit of a battery, typically consisting of a positive electrode, a negative electrode, and a separator. Lithium-ion cells primarily function by the movement of lithium ions between the positive and negative electrodes. In cylindrical cells, a three-layer thin-film structure is wound into a cylindrical electrode assembly, while in cuboid cells, the thin-film structure is wound or stacked into an electrode assembly with a roughly cuboid shape.

[0018] A positive electrode generally includes a positive current collector and a positive active material layer. The positive active material layer is coated on at least one surface of the positive current collector and includes: a positive active material, a conductive agent, and a binder. The positive active material includes, but is not limited to, at least one of the following: lithium phosphates, lithium transition metal oxides and their respective modified compounds, or other conventional materials that can be used as positive electrode active materials in batteries. These positive active materials can be used alone or in combination. Lithium phosphates include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also abbreviated as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also known as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM622), LiNi0.8 Co 0.1 Mn 0.1 O2 (also known as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0019] The positive electrode conductive agent includes, but is not limited to, one or more combinations of graphite, superconducting carbon, carbon black (such as acetylene black, Ketjen black, SuperP, etc.), carbon nanotubes, graphene and carbon nanofibers.

[0020] The positive electrode binder includes, but is not limited to, one or more combinations of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, carboxymethyl chitosan, etc.

[0021] The negative electrode sheet includes a negative electrode current collector and a negative electrode active layer disposed on at least one surface of the negative electrode current collector. The negative electrode current collector is a conductive metal foil, which can be made of stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium with a silver-plated surface. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, copper, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). The negative electrode active layer includes a negative electrode active material, a conductive agent, and a binder.

[0022] The negative electrode active material can be carbon-based materials such as graphite, porous carbon, hard carbon, soft carbon, and mesophase carbon microspheres, or silicon-based materials such as elemental silicon, silicon oxides, silicon-carbon composites, and silicon-nitrogen composites. The conductive agent can be conductive carbon black, carbon nanotubes, etc., and the binder can be styrene-butadiene rubber, polyacrylic acid, etc.

[0023] In some implementations, reference Figures 4 to 6 As shown, the positive electrode 31 is welded to the positive electrode tab 210 to form a first solder mark 211, and the negative electrode 32 is welded to the negative electrode tab 220 to form a second solder mark 221.

[0024] In the above manner, the positive electrode plate 31 and the positive electrode tab 210, as well as the negative electrode plate 32 and the negative electrode tab 220, can be connected by welding, thereby improving the stability of the connection between the positive electrode plate 31 and the positive electrode tab 210, and improving the stability of the connection between the negative electrode plate 32 and the negative electrode tab 220.

[0025] In some implementations, reference Figures 4 to 6 As shown, in the lead-out direction of the tab 2, the minimum distance between the end of the positive electrode 31 near the cell 1 and the first solder mark 211 is L1mm, where L1 satisfies 0.5mm≤L1mm≤5mm; and / or, the minimum distance between the end of the negative electrode 32 near the cell 1 and the second solder mark 221 is L1mm, where L1 satisfies 0.5mm≤L1mm≤5mm.

[0026] By limiting the minimum distance between the end of the positive electrode 31 near the cell 1 and the first solder mark 211 and / or the minimum distance between the end of the negative electrode 32 near the cell 1 and the second solder mark 221, the risk of the positive electrode 31 and / or the negative electrode 32 being inserted into the cell 1 due to excessive L1 can be reduced or prevented, or the problem of the first solder mark 211 and / or the second solder mark 221 being too small and having poor current carrying capacity can be prevented. It can also reduce or prevent the situation where the length of the positive electrode 31 and / or the negative electrode 32 exposed outside the pouch battery is too long and redundant due to excessive L1, thereby reducing the possibility of short circuit between the positive electrode 31 and / or the negative electrode 32 and the pouch battery casing or other conductive components.

[0027] It can be understood that when L1 is too large, the ends of the positive electrode 31 and / or the negative electrode 32 are prone to being underutilized. That is, the areas without solder marks at the ends of the positive electrode 31 and / or the negative electrode 32 cannot achieve current flow, which is equivalent to indirectly causing the area of ​​the first solder mark 211 and / or the second solder mark 221 to be too small.

[0028] Furthermore, the specific size of L1 mentioned in the above embodiments can be any suitable size selected within the range. For example, L1 can be 0.5mm, 1mm, 2mm, 4mm, 5mm, etc., or any size between any two adjacent values ​​mentioned above.

[0029] In some implementations, reference Figures 4 to 6 As shown, in the lead-out direction of the tab 2, the minimum distance between the end of the positive tab 210 away from the cell 1 and the first solder mark 211 is L2mm, and L2 satisfies 0.8mm≤L2mm≤7mm; and / or, the minimum distance between the end of the negative tab 220 away from the cell 1 and the second solder mark 221 is L2mm, and L2 satisfies 0.8mm≤L2mm≤7mm.

[0030] By limiting the minimum distance between the end of the positive electrode tab 210 away from the cell 1 and the first solder mark 211 and / or the minimum distance between the end of the negative electrode tab 220 away from the cell 1 and the second solder mark 221, the risk of the positive electrode plate 31 and / or the negative electrode plate 32 being inserted into the cell 1 due to an excessively small L2 can be avoided or prevented, or the problem of the first solder mark 211 and / or the second solder mark 221 having a poor current carrying capacity due to an excessively small area can be avoided or prevented. In addition, the situation where the positive electrode plate 31 and / or the negative electrode plate 32 are exposed to the outside of the pouch battery due to an excessively large L2 can also be reduced or prevented, thereby reducing the possibility of short circuits between the positive electrode plate 31 and / or the negative electrode plate 32 and the pouch battery casing or other conductive components.

[0031] Furthermore, the specific size of L2 can be any suitable size within the specified range, such as 0.8mm, 1mm, 2mm, 5mm, 7mm, or any suitable size between any two adjacent values.

[0032] Furthermore, |L1mm-L2mm| satisfies 0mm≤|L1mm-L2mm|≤6.5mm.

[0033] By limiting the range as described above, when the value of |L1mm-L2mm| exceeds the maximum value, the first solder mark 211 will be closer to the edge of the positive electrode tab 210, and / or the second solder mark 221 will be closer to the edge of the negative electrode tab 220, which may easily lead to poor welding. The lower limit of |L1mm-L2mm| is 0, that is, the value of L1 is equal to L2. At this time, the first solder mark 211 is located at the center of the overlapping position of the positive electrode tab 210 and the positive electrode plate 31, and / or the second solder mark 221 is located at the center of the overlapping position of the negative electrode tab 220 and the negative electrode plate 32, which can give the positive electrode tab 210 and the positive electrode plate 31 and / or the negative electrode tab 220 and the negative electrode plate 32 better connection stability.

[0034] Furthermore, the specific size of |L1mm-L2mm| can be any suitable value within the specified range, such as 0mm, 2mm, 4mm, 6mm, 6.5mm, or any suitable size between any two adjacent values.

[0035] In some implementations, reference Figures 4 to 6 As shown, the area of ​​the first solder mark 211 is M1mm. 2 M1 meets 90mm 2 ≤M1mm 2 ≤500mm 2 ; and / or, the area of ​​the second solder mark 221 is M1mm. 2 M1 meets 90mm 2≤M1mm 2 ≤500mm 2 .

[0036] By limiting the area of ​​the first solder mark 211 and / or the second solder mark 221, the current carrying capacity of the pouch battery can be reduced or avoided due to the solder mark being too small, and the space required to arrange the solder mark can also be reduced or avoided due to the solder mark being too large. This reduces the space occupied by the pouch battery, allowing more space to be used to arrange the cell 1 and improve the energy density of the pouch battery.

[0037] Furthermore, the aforementioned M1 can be any suitable size within the specified range, for example, it can be 90mm. 2 100mm 2 120mm 2 300mm 2 500mm 2 Alternatively, it could be any suitable size between any two adjacent values ​​mentioned above.

[0038] In some implementations, reference Figures 4 to 6 As shown, in the width direction of the tab 2, the size of the first solder mark 211 is b1, the width of the positive tab 210 is b2, and the width of the positive electrode sheet 31 is b3, with b1 / b2 and b1 / b3 both being greater than or equal to 0.4; and / or, the width of the second solder mark 221 is b1, the width of the negative tab 220 is b2, and the width of the positive electrode sheet 31 is b3, with b1 / b2 and b1 / b3 both being greater than or equal to 0.4.

[0039] By limiting the minimum values ​​of the ratios b1 / b2 and b1 / b3 as described above, the utilization rate of the positive tab 210 and the positive electrode plate 31 and / or the negative tab 220 and the negative electrode plate 32 can be improved. This can increase the area of ​​the first solder mark 211 and / or the second solder mark 221, thereby increasing the current-carrying area of ​​the pouch battery. It can also improve the stability of the connection between the positive tab 210 and the positive electrode plate 31 and / or the negative tab 220 and the negative electrode plate 32.

[0040] Furthermore, the specific values ​​of b1 / b2 and b1 / b3 can be chosen as any suitable value, such as 0.4, 0.5, 0.6, 0.7, etc., provided that the above range is satisfied.

[0041] In another embodiment, reference Figures 4 to 6 As shown, the area of ​​the first solder mark 211 on the projection along the thickness direction of cell 1 is M2mm. 2 The area of ​​the second solder mark 221 is M3mm. 2 |M2mm 2-M3mm 2 |Meets 0mm 2 ≤|M2mm 2 -M3mm 2 ≤60mm 2 .

[0042] By limiting the area difference between the first solder mark 211 and the second solder mark 221 as described above, it is possible to prevent or reduce the situation where the difference between the first solder mark 211 and the second solder mark 221 is too large, resulting in a large difference in the overcurrent capacity on both sides of the pouch battery. When the overcurrent capacity on both sides of the pouch battery is too large, it will affect the overall overcurrent of the pouch battery and cause excessive local resistance, which will easily increase the heat generation of the pouch battery and affect its safety performance. Therefore, the area difference between the first solder mark 211 and the second solder mark 221 is ideally zero. At this time, the overcurrent of the pouch battery at the positive tab 210 and the negative tab 220 is equal, and the area difference is limited to 0 mm. 2 Up to 60mm 2 Between them, a certain overflow difference is allowed between the positive tab 210 and the negative tab 220 without affecting the safety performance of the pouch battery.

[0043] Furthermore, the aforementioned |M2mm 2 -M3mm 2 The specific size can be any suitable value as long as it meets the range requirements, such as 0mm. 2 20mm 2 40mm 2 60mm 2 Alternatively, it could be any suitable size between any two adjacent values ​​mentioned above.

[0044] In some implementations, reference Figures 2 to 6 As shown, the soft-pack battery also includes a housing 4, a first sealing member 430, and a second sealing member 440. The housing 4 is provided with a first lead-out hole 410 and a second lead-out hole 420. The positive electrode plate 31 and the negative electrode plate 32 are respectively passed through the first lead-out hole 410 and the second lead-out hole 420 and led outward. The first sealing member 430 is disposed between the first lead-out hole 410 and the positive electrode plate 31, and the second sealing member 440 is disposed between the second lead-out hole 420 and the negative electrode plate 32.

[0045] In the above manner, the first sealing member 430 can seal the positive electrode plate 31, and the second sealing member 440 can seal the negative electrode plate 32.

[0046] In some implementations, reference Figures 2 to 6As shown, the first solder mark 211 is located inside the housing 4. In the length direction of the cell 1, the distance between the first solder mark 211 and the first seal 430 is L4mm, where L4mm satisfies 1mm≤L4mm≤5mm; and / or, the second solder mark 221 is located inside the housing 4. In the length direction of the cell 1, the distance between the second solder mark 221 and the second seal 440 is L4mm, where L4mm satisfies 1mm≤L4mm≤5mm.

[0047] Through the above methods, the first seal 430 and the second seal 440 can further achieve the sealing of the pouch battery, that is, they can be combined. Figures 3 to 6 As shown, when the two electrode output components 3 are respectively inserted into the first lead-out hole 410 and the second lead-out hole 420, the first sealing member 430 can be placed between the first lead-out hole 410 and the positive electrode plate 31 to achieve a seal at the positive electrode tab 210 of the soft-pack battery; similarly, the second sealing member 440 can be placed between the second lead-out hole 420 and the negative electrode plate 32 to achieve a seal at the negative electrode tab 220 of the soft-pack battery, thereby improving the overall sealing performance of the soft-pack battery, reducing leakage during use, and... By limiting the distance L4 between the first seal 430 and the first weld mark 211 and / or the second seal 440 and the second weld mark 221, the heat generated by the first weld mark 211 or the second weld mark 221 during the operation of the pouch battery can be reduced or avoided, which may lead to sealing failure of the first seal 430 or the second seal 440. It can also reduce or prevent the problem of excessive activity space on the welding side of the electrode output component 3 and the tab 2, thereby reducing the tearing at the first weld mark 211 or the second weld mark 221 caused by the vibration of the pouch battery.

[0048] It can be understood that when L4 is less than the minimum value mentioned above, the distance between the first seal 430 and the first weld mark 211 and / or the second seal 440 and the second weld mark 221 is too small. Since the resistance of the first weld mark 211 and / or the second weld mark 221 is relatively large during the operation of the pouch battery, heat generation is likely to occur during charging and discharging of the pouch battery, which will cause the heat at the first weld mark 211 and / or the second weld mark 221 to affect the sealing effect of the first seal 430 and / or the second seal 440, resulting in a poorer sealing effect. Conversely, when L4 is greater than the maximum value mentioned above, the space for movement on the side where the electrode output component 3 is welded to the tab 2 will increase. When the pouch battery is subjected to vibration, it is easier to cause tearing at the first weld mark 211 or the second weld mark 221, which may lead to the breakage of the electrode output component 3 and the tab 2. Therefore, limiting the range of L4 to between 1mm and 5mm is a relatively reasonable arrangement.

[0049] Furthermore, the specific size of L4 can be any suitable size between 1mm and 5mm, such as 1mm, 3mm, 5mm, etc., or any suitable size between any two adjacent values.

[0050] It should be noted that the specific materials used for the first sealing element 430 and / or the second sealing element 440 mentioned in the above embodiments can be any material with excellent sealing performance, such as polypropylene (CPP) or polyethylene (PE), polyethylene terephthalate (PET), polybutylene succinate (PBS), polyimide (PI) and other insulating materials.

[0051] In some implementations, reference Figures 2 to 6 As shown, along the length of the cell 1, the contact length between the first sealing member 430 and the positive electrode plate 31 is greater than or equal to 5 mm and less than or equal to 20 mm; and / or, the contact length between the second sealing member 440 and the negative electrode plate 32 is greater than or equal to 5 mm and less than or equal to 30 mm.

[0052] By limiting the sealing length of the first seal 430 and / or the second seal 440, the sealing stability of the first seal 430 and / or the second seal 440 for the soft-pack battery can be guaranteed, and the situation where the sealing length of the first seal 430 and / or the second seal 440 is too long, resulting in the need to set the electrode output component 3 to be too long, can also be prevented.

[0053] This can be understood as follows: the contact length between the first sealing element 430 and the positive electrode plate 31 and / or the contact length between the second sealing element 440 and the negative electrode plate 32 should not be too long or too short. When the contact length between the first sealing element 430 and the positive electrode plate 31 and / or the contact length between the second sealing element 440 and the negative electrode plate 32 is less than the minimum value specified above, it is easy to cause the sealing length of the first sealing element 430 and / or the second sealing element 440 to be too short, thereby reducing the sealing stability of the soft pack battery. Conversely, when the contact length between the first sealing element 430 and the positive electrode plate 31 and / or the contact length between the second sealing element 440 and the negative electrode plate 32 is greater than the maximum value specified above, it is necessary to configure an excessively long electrode output element 3. As the length of the electrode output element 3 increases, its own resistance will also increase, and it will further increase the volume occupied by the soft pack battery.

[0054] Furthermore, the contact length between the first sealing member 430 and the positive electrode sheet 31 can be selected arbitrarily within the above range, such as 5mm, 10mm, 20mm, etc., or any suitable size between any two adjacent values ​​mentioned above. The contact length between the second sealing member 440 and the negative electrode sheet 32 ​​can also be selected arbitrarily within the above range, such as 5mm, 10mm, 20mm, 30mm, etc., or any suitable size between any two adjacent values ​​mentioned above.

[0055] In some implementations, reference Figures 1 to 6 As shown, in the lead-out direction of tab 2, the distance between the first solder mark 211 and the end of the positive tab 210 leading out of the cell 1 is greater than or equal to 0.5 mm and less than or equal to 5 mm; and / or, the distance between the second solder mark 221 and the end of the negative tab 220 leading out of the cell 1 is greater than or equal to 0.5 mm and less than or equal to 5 mm.

[0056] By limiting the distance between the first solder mark 211 and the end of the positive electrode tab 210 leading out of the battery cell 1, and / or the distance between the second solder mark 221 and the end of the negative electrode tab 220 leading out of the battery cell 1, it can be understood that when the distance is too large, the movement space of the positive electrode tab 210 and / or the negative electrode tab 220 in the direction of the electrode tab 2 will be too large, which will easily cause vibration at this point, thereby affecting the strength of the first solder mark 211 and / or the second solder mark 221; while when the distance is too small, it is easy to cause the positive electrode plate 31 and / or the negative electrode plate 32 to be inserted into the battery cell 1.

[0057] In some implementations, reference Figure 3 As shown, along the length of the cell 1, the distance between the positive electrode plate 31 and the cell 1 is greater than or equal to 3 mm and less than or equal to 10 mm; and / or, the distance between the negative electrode plate 32 and the cell 1 is greater than or equal to 3 mm and less than or equal to 10 mm.

[0058] In the above manner, when assembling the pouch battery, a certain distance needs to be maintained between the positive electrode 31 and / or the negative electrode 32 and the cell 1 to ensure a stable connection between the tab 2 and the positive electrode 31 and / or the negative electrode 32 and the cell 1. It can be understood that when the distance between the positive electrode 31 and / or the negative electrode 32 and the cell 1 exceeds the aforementioned maximum value, the tab 2 may become excessively long. When the pouch battery is subjected to external vibrations, the tab 2 is also prone to vibration, and in severe cases, the tab 2 may even detach from the positive electrode 31 and / or the negative electrode 32. There is a risk of tearing of the positive electrode plate 31 and / or the negative electrode plate 32. When the distance between the positive electrode plate 31 and / or the negative electrode plate 32 and the cell 1 is less than the minimum value specified above, it is easy for the positive electrode plate 31 and / or the negative electrode plate 32 to be too close to the cell 1, which may lead to the risk of the positive electrode plate 31 and / or the negative electrode plate 32 being inserted into the cell 1 and causing damage to the soft pack battery. Therefore, setting the distance between the positive electrode plate 31 and / or the negative electrode plate 32 and the cell 1 in the range of 3mm to 10mm is a better option.

[0059] Furthermore, in the above embodiments, the distance between the positive electrode plate 31 and the battery cell 1, and / or the distance between the negative electrode plate 32 and the battery cell 1 can be selected from any suitable value within a certain range, such as 3mm, 5mm, 7mm, 10mm, etc. In addition, the distance between the positive electrode plate 31 and the battery cell 1 and the distance between the negative electrode plate 32 and the battery cell 1 can be the same or different, and the appropriate value can be selected according to the actual situation.

[0060] In some implementations, reference Figures 1 to 6 As shown, the soft-pack battery has a first reference surface 5 in the length direction. The first reference surface 5 divides the cell 1 equally along the thickness direction. On the projection surface of the cell 1 in the width direction, the positive electrode sheet 31 and the negative electrode sheet 32 ​​are both located on the same side of the first reference surface 5.

[0061] In the above manner, when the positive electrode 31 and the negative electrode 32 are both located on the same side of the first reference surface 5, when the soft-pack battery is vibrated, the positive electrode 31 and the negative electrode 32 located on the same side can make the force on both ends of the soft-pack battery more uniform, thereby reducing the tearing caused by vibration at the first solder mark 211 or the second solder mark 221.

[0062] In some implementations, reference Figure 2 and Figure 3 As shown, in the thickness direction of the cell 1, the distance between the positive electrode sheet 31 and the first reference surface 5 is L3, and L3 satisfies less than or equal to 15mm; and / or, the distance between the negative electrode sheet 32 ​​and the first reference surface 5 is L3, and L3 satisfies less than or equal to 15mm.

[0063] In the above manner, during the manufacturing process of the soft-pack battery casing 4, such as the process of punching holes, the depth of the holes in the casing 4 is easily affected by the characteristics of the material itself. For example, when punching holes with aluminum-plastic film material, the holes can be single or two. When there are two holes, the two holes are also prone to different depths due to errors generated during the processing. When the depths of the two holes are different, there will be a difference between the position of the cell 1 and the first reference surface 5. This difference is the size of L3 mentioned above.

[0064] This can be understood as follows: the lower limit of L3 can be zero, and the upper limit can be the depth of the recess of a single shell 4. The specific size can be selected according to the actual processing of the shell 4, such as the 15mm specified above. Furthermore, L3 can also be selected in any suitable size within the range of 0mm to 15mm, such as 0mm, 5mm, 10mm, 15mm, etc., or any suitable size between any two adjacent values ​​mentioned above. This embodiment will not impose any further limitations here.

[0065] In some implementations, reference Figures 1 to 6 As shown, in the thickness direction of the cell 1, at the connection between the positive electrode sheet 31 and the positive electrode tab 210, the distance between the end of the positive electrode tab 210 connected to the cell 1 and the first reference surface 5 is less than L3; and / or, at the connection between the negative electrode sheet 32 ​​and the negative electrode tab 220, the distance between the end of the negative electrode tab 220 connected to the cell 1 and the first reference surface 5 is less than L3.

[0066] By setting the distance between the positive tab 210 connected to the cell 1 and the first reference surface 5 and / or the distance between the negative tab 220 connected to the cell 1 and the first reference surface 5 to be less than L3, the spacing between the positive tab 210 and / or the negative tab 220 and the first reference surface 5 in the thickness direction of the pouch battery can be further reduced, so that the positive tab 210 and / or the negative tab 220 can be closer to the first reference surface 5. In this way, when the pouch battery is subjected to external vibration, the vibration of the positive tab 210 and / or the negative tab 220 can be further reduced, thereby reducing the possibility of the tab 2 tearing.

[0067] In some implementations, reference Figure 2 and Figure 3 As shown, both the positive electrode tab 210 and the negative electrode tab 220 are provided with a dispersing section 201 close to the battery cell 1 and a gathering section 202 away from the battery cell 1. The dimension of the gathering section 202 along the thickness direction of the battery cell 1 is d1mm, and the dimension of the positive electrode sheet 31 or the negative electrode sheet 32 ​​along the thickness direction of the battery cell 1 is d2mm. The ratio of d1 / d2 satisfies greater than or equal to 0.15 and less than or equal to 1.3.

[0068] In the above manner, the closer d1 and d2 are, that is, the closer the ratio is to 1, the more stable the welding effect of the positive electrode tab 210 to the positive electrode sheet 31 or the negative electrode sheet 32, and the welding effect of the negative electrode tab 220 to the positive electrode sheet 31 or the negative electrode sheet 32. However, when the difference between d1 and d2 is large, the relatively thin side is prone to being welded through during welding, which can easily lead to poor welding. Therefore, keeping d1 and d2 as close as possible can improve the welding effect.

[0069] Furthermore, the specific size of d1 / d2 can be any suitable size within the specified range, such as 0.15, 0.2, 0.6, 1, 1.3, etc., or any suitable size between any two adjacent values.

[0070] Furthermore, combined Figure 2 and Figure 3 As shown, the dimension of cell 1 along its own thickness direction is d3mm, and (d1+d2) / d3 satisfies greater than or equal to 0.05 and less than or equal to 0.2.

[0071] By limiting the range of (d1+d2) / d3 as described above, the thickness of the tab 2 can be maintained without increasing the current-carrying area of ​​the pouch battery. In other words, when the value of (d1+d2) / d3 is less than the minimum value, the current-carrying area of ​​the pouch battery tends to decrease, resulting in a poorer current-carrying capacity. Conversely, when the value of (d1+d2) / d3 is greater than the maximum value, the tab 2 tends to be too thick, which can occupy too much space inside the pouch battery.

[0072] Furthermore, the specific size of (d1+d2) / d3 can be any suitable size within the specified range, such as 0.05, 0.1, 0.2, or any suitable size between any two adjacent values.

[0073] In some implementations, reference Figure 1 and Figure 2 As shown, the length of cell 1 along its own length direction is greater than or equal to 100mm and less than or equal to 1800mm.

[0074] By limiting the length of cell 1 as described above, when the extension length of cell 1 exceeds the maximum value, the vibration of cell 1 will be more pronounced when the pouch battery is subjected to external vibration, affecting the overall safety performance. When the extension length of cell 1 is less than the minimum value, the energy density of the pouch battery will also be reduced. Therefore, limiting the extension length of cell 1 to 100mm and less than or equal to 1800mm ensures both the energy density of the pouch battery and reduces the vibration experienced by cell 1.

[0075] Furthermore, the extension length of the battery cell 1 mentioned in the above embodiments can be any suitable size within the above range, such as 100mm, 500mm, 1000mm, 1500mm, 1800mm, etc., or any suitable size between any two adjacent values ​​mentioned above.

[0076] Although 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 all such modifications and variations fall within the scope of protection claimed by the present invention.

Claims

1. A soft-pack battery, characterized in that, include: Battery cell (1); The electrode (2) includes a positive electrode (210) and a negative electrode (220), and along a first direction, the positive electrode (210) and the negative electrode (220) are respectively led out from opposite ends of the battery cell (1); The electrode output device (3) includes a positive electrode plate (31) and a negative electrode plate (32). The positive electrode plate (31) and the negative electrode plate (32) are respectively connected to the positive electrode tab (210) and the negative electrode tab (220) on the side away from the battery cell (1). Along the first direction, the positive electrode plate (31) and the positive electrode tab (210) overlap at least partially, and the negative electrode plate (32) and the negative electrode tab (220) overlap at least partially. The overlap direction of the positive electrode plate (31) and the positive electrode tab (210) is the same as the overlap direction of the negative electrode plate (32) and the negative electrode tab (220).

2. The soft-pack battery according to claim 1, characterized in that, The positive electrode sheet (31) is welded to the positive electrode tab (210) to form a first solder mark (211), and the negative electrode sheet (32) is welded to the negative electrode tab (220) to form a second solder mark (221).

3. The soft-pack battery according to claim 2, characterized in that, In the lead-out direction of the tab (2), the minimum distance between the end of the positive electrode plate (31) closest to the cell (1) and the first solder mark (211) is L1mm, wherein L1 satisfies 0.5mm≤L1mm≤5mm; and / or, The minimum distance between the end of the negative electrode sheet (32) near the cell (1) and the second solder mark (221) is L1mm, and L1 satisfies 0.5mm≤L1mm≤5mm.

4. The soft-pack battery according to claim 3, characterized in that, In the lead-out direction of the tab (2), the minimum distance between the end of the positive tab (210) away from the cell (1) and the first solder mark (211) is L2mm, wherein L2 satisfies 0.8mm≤L2mm≤7mm; and / or, The minimum distance between the end of the negative electrode tab (220) away from the battery cell (1) and the second solder mark (221) is L2mm, and L2 satisfies 0.8mm≤L2mm≤7mm.

5. The soft-pack battery according to claim 4, characterized in that, |L1mm-L2mm| satisfies 0mm≤|L1mm-L2mm|≤6.5mm.

6. The soft-pack battery according to claim 2, characterized in that, The area of ​​the first solder mark (211) is M1mm. 2 The M1 satisfies 90mm 2 ≤M1mm 2 ≤500mm 2 ; and / or, The area of ​​the second solder mark (221) is M1mm. 2 The M1 satisfies 90mm 2 ≤M1mm 2 ≤500mm 2 .

7. The soft-pack battery according to claim 2, characterized in that, In the width direction of the tab (2), the size of the first solder mark (211) is b1, the size of the positive tab (210) is b2, and the size of the positive electrode sheet (31) is b3, where b1 / b2 and b1 / b3 are both greater than or equal to 0.4; and / or, The size of the second solder mark (221) is b1, the size of the negative electrode tab (220) is b2, and the size of the positive electrode sheet (31) is b3. The ratios of b1 / b2 and b1 / b3 are both greater than or equal to 0.

4.

8. The soft-pack battery according to claim 2, characterized in that, On the projection of the cell (1) along its thickness direction, the area of ​​the first solder mark (211) is M2mm. 2 The area of ​​the second solder mark (221) is M3mm. 2 |M2mm 2 -M3mm 2 |Meets 0mm 2 ≤|M2mm 2 -M3mm 2 ≤60mm 2 .

9. The soft-pack battery according to claim 2, characterized in that, The soft-pack battery also includes a housing (4), a first sealing element (430), and a second sealing element (440). The housing (4) is provided with a first lead-out hole (410) and a second lead-out hole (420). The positive electrode plate (31) and the negative electrode plate (32) are respectively passed through the first lead-out hole (410) and the second lead-out hole (420) and led outward. The first sealing element (430) is disposed between the first lead-out hole (410) and the positive electrode plate (31), and the second sealing element (440) is disposed between the second lead-out hole (420) and the negative electrode plate (32).

10. The soft-pack battery according to claim 9, characterized in that, The first solder mark (211) is located inside the housing (4). Along the length of the cell (1), the distance between the first solder mark (211) and the first seal (430) is L4mm, where L4mm satisfies 1mm ≤ L4mm ≤ 5mm; and / or, The second solder mark (221) is located inside the housing (4). In the length direction of the cell (1), the distance between the second solder mark (221) and the second seal (440) is L4mm, and L4mm satisfies 1mm≤L4mm≤5mm.

11. The soft-pack battery according to claim 10, characterized in that, In the length direction of the battery cell (1), the contact length between the first sealing member (430) and the positive electrode sheet (31) is greater than or equal to 5 mm and less than or equal to 20 mm; and / or, the contact length between the second sealing member (440) and the negative electrode sheet (32) is greater than or equal to 5 mm and less than or equal to 30 mm.

12. The soft-pack battery according to claim 2, characterized in that, In the lead-out direction of the tab (2), the distance between the first solder mark (211) and the end of the positive tab (210) leading out of the cell (1) is greater than or equal to 0.5 mm and less than or equal to 5 mm; and / or, The distance between the second solder mark (221) and the end of the negative electrode tab (220) leading out of the cell (1) is greater than or equal to 0.5 mm and less than or equal to 5 mm.

13. The soft-pack battery according to claim 1, characterized in that, Along the length of the battery cell (1), the distance between the positive electrode plate (31) and the battery cell (1) is greater than or equal to 3 mm and less than or equal to 10 mm; and / or, The distance between the negative electrode sheet (32) and the battery cell (1) is greater than or equal to 3 mm and less than or equal to 10 mm.

14. The soft-pack battery according to claim 1, characterized in that, The soft-pack battery has a first reference surface (5) in the length direction. The first reference surface (5) divides the cell (1) into equal parts in the thickness direction. On the projection surface of the cell (1) in the width direction, the positive electrode sheet (31) and the negative electrode sheet (32) are both located on the same side of the first reference surface (5).

15. The soft-pack battery according to claim 14, characterized in that, In the thickness direction of the battery cell (1), the distance between the positive electrode sheet (31) and the first reference surface (5) is L3, wherein L3 is less than or equal to 15 mm; and / or, The distance between the negative electrode sheet (32) and the first reference surface (5) is L3, and L3 is less than or equal to 15mm.

16. The soft-pack battery according to claim 15, characterized in that, In the thickness direction of the cell (1), at the connection between the positive electrode sheet (31) and the positive electrode tab (210), the positive electrode tab (210) is closer to the first reference surface (5) than the positive electrode sheet (31); and / or, at the connection between the negative electrode sheet (32) and the negative electrode tab (220), the distance between the end of the negative electrode tab (220) connected to the cell (1) and the first reference surface (5) is less than L3.

17. The soft-pack battery according to claim 1, characterized in that, Both the positive electrode tab (210) and the negative electrode tab (220) are provided with a dispersing section (201) close to the battery cell (1) and a converging section (202) away from the battery cell (1). The converging section (202) has a dimension of d1 mm along the thickness direction of the battery cell (1), and the positive electrode sheet (31) or the negative electrode sheet (32) has a dimension of d2 mm along the thickness direction of the battery cell (1). The ratio of d1 / d2 is greater than or equal to 0.15 and less than or equal to 1.

3.

18. The soft-pack battery according to claim 17, characterized in that, The cell (1) has a dimension of d3mm along its own thickness direction, and (d1+d2) / d3 satisfies greater than or equal to 0.05 and less than or equal to 0.

2.

19. The soft-pack battery according to claim 1, characterized in that, The battery cell (1) has an extension length of 100 mm or more and 1800 mm or less along its own length direction.

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