Pouch cell

Abstract

The utility model relates to a kind of soft package batteries, including electric core and adhesive tape, electric core includes opposite first side wall and second side wall;Adhesive tape is inlaid in electric core along the circumference of electric core, adhesive tape includes first adhesive tape and second adhesive tape, the first end of first adhesive tape and the first end of second adhesive tape overlap and form first overlap area in first side wall, the second end of first adhesive tape and the second end of second adhesive tape overlap and form second overlap area in second side wall;In the projection on the plane where first side wall or second side wall is, first overlap area and second overlap area at least partially do not overlap each other, the soft package battery can reduce the thickness of electric core in local area, reduce the case of pressure loss caused by electric core thermal expansion.

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 cells of soft-pack batteries are usually constrained in shape and position by two or more adhesive tapes to keep the cells in a stacked or wound arrangement. When the tapes are wrapped around the outer periphery of the cells, the two ends of the tapes are usually fixed by stacking. The stacked area of ​​the tapes can easily make the cells too thick in some places. Since batteries generally consist of multiple cells stacked together, the tapes in the stacked area of ​​the cells will usually cause greater pressure when the cells are heated and expanded, which can easily cause cell pressure damage. Utility Model Content

[0003] Based on the above-mentioned technical problems, this utility model provides a soft-pack battery to reduce the thickness of the battery cell in local areas and reduce the pressure loss caused by thermal expansion of the battery cell, 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, the battery cell including opposing first and second sidewalls; and an adhesive tape, which is attached to the battery cell around its circumference, the adhesive tape including a first adhesive tape and a second adhesive tape, wherein a first end of the first adhesive tape and a first end of the second adhesive tape overlap on the first sidewall to form a first overlapping area, and a second end of the first adhesive tape and a second end of the second adhesive tape overlap on the second sidewall to form a second overlapping area; the first overlapping area and the second overlapping area do not overlap on the projection of the plane containing the first sidewall or the second sidewall.

[0005] Through the above technical solution, namely the soft-pack battery provided by this utility model, the soft-pack battery can be fixed by wrapping the battery cell with tape, and a first overlapping area and a second overlapping area are formed on the first and second sidewalls of the battery cell respectively by the first tape and the second tape. In order to reduce the problem of local excessive thickness of the tape caused by the first overlapping area and the second overlapping area, the first overlapping area and the second overlapping area can be arranged in a staggered manner on the projection of the plane where the first sidewall or the second sidewall is located, at least partially not overlapping each other. Under this arrangement, due to the staggered arrangement of the first overlapping area and the second overlapping area, the local excessive thickness of the soft-pack battery in the thickness direction can be further reduced. When the battery cell is heated and expanded, the pressure loss of the battery cell by the tape can also be reduced by the staggered first overlapping area and the second overlapping area. 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 1 This is a schematic diagram of the structure of a soft-pack battery provided in an exemplary embodiment of this utility model; Figure 2 This is a schematic diagram of the other side of the soft-pack battery provided in an exemplary embodiment of the present utility model; Figure 3 This is a side view of a pouch battery provided in an exemplary embodiment of the present utility model; Figure 4 This is a top view of a soft-pack battery provided in an exemplary embodiment of the present utility model; Figure 5 This is a bottom view of the soft-pack battery provided in an exemplary embodiment of the present utility model; Figure 6 This is a top view of another embodiment of the soft-pack battery provided in the exemplary embodiments of this utility model; Figure 7 This is a bottom view of another embodiment of the soft-pack battery provided in an exemplary embodiment of this utility model; Figure 8 This is a schematic diagram of the structure of a soft-pack battery with a casing provided in an exemplary embodiment of this utility model.

[0008] Explanation of reference numerals in the attached figures: 1. Battery cell; 101. First central axis; 110. First sidewall; 120. Second sidewall; 130. Third sidewall; 140. Fourth sidewall; 2. Adhesive tape; 210. First adhesive tape; 220. Second adhesive tape; 230. First overlapping area; 240. Second overlapping area; 3. Earpiece. 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 cells of soft-pack batteries are usually constrained in shape and position by two or more adhesive tapes to keep the cells in a stacked or wound arrangement. When the tapes are wrapped around the outer periphery of the cells, the two ends of the tapes are usually fixed by stacking. The stacked area of ​​the tapes can easily make the cells too thick in some places. Since batteries generally consist of multiple cells stacked together, the tapes in the stacked area of ​​the cells will usually cause greater pressure when the cells are heated and expanded, which can easily cause cell pressure damage.

[0011] Based on the above-mentioned technical problems, this utility model provides a soft-pack battery, as shown in the reference. Figures 1 to 8 As shown, the pouch battery includes a cell 1 and an adhesive tape 2. The cell 1 includes a first sidewall 110 and a second sidewall 120. The adhesive tape 2 is attached to the cell 1 around its circumference. The adhesive tape 2 includes a first adhesive tape 210 and a second adhesive tape 220. The first end of the first adhesive tape 210 overlaps with the first segment of the second adhesive tape 220 on the first sidewall 110 to form a first overlapping area 230. The second end of the first adhesive tape 210 overlaps with the second end of the second adhesive tape 220 on the second sidewall 120 to form a second overlapping area 240. On the projection of the plane containing the first sidewall 110 or the second sidewall 120, the first overlapping area 230 and the second overlapping area 240 do not overlap each other at least partially.

[0012] Through the above technical solution, namely the soft-pack battery provided by this utility model, the soft-pack battery can be fixed by wrapping the cell 1 with tape 2, and the first overlapping area 230 and the second overlapping area 240 are formed on the first side wall 110 and the second side wall 120 opposite to the cell 1 respectively by the first tape 210 and the second tape 220. In order to reduce the problem of local overthickness of tape 2 caused by the first overlapping area 230 and the second overlapping area 240, the first overlapping area 230 and the second overlapping area 240 can be staggered on the projection of the first side wall 110 or the second side wall 120 without overlapping each other at least partially. Under this arrangement, due to the staggered arrangement of the first overlapping area 230 and the second overlapping area 240, the local overthickness of the soft-pack battery in the thickness direction can be further reduced. When the cell 1 is heated and expanded, the pressure loss of tape 2 on cell 1 can also be reduced by the staggered first overlapping area 230 and the second overlapping area 240.

[0013] It should be noted that, in the above embodiments, the thickness direction of the soft-pack battery can be as follows: Figures 1 to 7 In the diagram, the direction indicated by the Y-arrow in any of the attached figures, and the same interpretation can be made regarding the thickness direction of the pouch battery mentioned below. The length direction of the pouch battery mentioned below can be understood as... Figures 1 to 7 The direction indicated by the X arrow in any of the attached diagrams, and the width direction of the pouch battery mentioned below, can be understood as... Figures 1 to 7 The direction pointed to by the Z arrow in any of the attached figures.

[0014] 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.

[0015] 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.

[0016] 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), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0017] 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.

[0018] 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.

[0019] The negative electrode sheet includes a negative current collector and a negative active layer disposed on at least one surface of the negative current collector. The negative 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 base material 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 base material (such as a polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). The negative active layer includes a negative active material, a conductive agent, and a binder.

[0020] 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.

[0021] In addition, pouch batteries typically include a casing disposed outside the cell 1. The casing is usually composed of three layers: an outer insulating layer, a metal layer, and an inner insulating layer. These three layers can also be made of materials that are relatively mature in the field of pouch batteries. For example, the outer insulating layer can be made of one or more of polycaprolactam, polyethylene terephthalate, or polybutylene succinate; the metal layer can be made of one or more of metals or alloys such as aluminum, aluminum alloy, copper, and nickel; and the inner insulating layer can be made of one or more of materials such as polypropylene film or cast polypropylene film.

[0022] Furthermore, when selecting the tape 2 mentioned in the above embodiments, it is necessary to consider insulation, electrolyte resistance, and mechanical strength. Commonly used tapes include Teflon tape, release paper bonding tape, biaxially oriented polypropylene tape, polyvinyl chloride tape, and high-temperature resistant polyethylene terephthalate tape.

[0023] In some implementations, reference Figures 3 to 7 As shown, the first sidewall 110 or the second sidewall 120 has a first central axis 101, which extends along the length of the pouch battery and divides the first sidewall 110 or the second sidewall 120 equally along the width of the pouch battery. The first central axis 101 is projected onto the plane where the first sidewall 110 or the second sidewall 120 is located. The first overlapping area 230 and the second overlapping area 240 are located on opposite sides of the first central axis 101.

[0024] By arranging the first overlapping area 230 and the second overlapping area 240 in the length direction of the pouch battery on opposite sides of the first central axis 101, the projections of the first overlapping area 230 and the second overlapping area 240 in the thickness direction of the pouch battery do not overlap and can be separated by a certain distance. In this way, in the thickness direction of the pouch battery, the overlap of the first overlapping area 230 and the second overlapping area 240 can be reduced or avoided, which would cause the pouch battery to be locally too thick. Furthermore, the loss of cell 1 caused by the local excessive thickness of the pouch battery can be reduced or avoided, which can further improve the battery cycle performance of the pouch battery.

[0025] It should be noted that the projection plane of the pouch battery along its length mentioned in the above embodiments can be understood as the projection along the direction of arrow X in any of the attached figures, that is... Figure 3 The view shown.

[0026] The cell material shedding mentioned in the above embodiments usually refers to the phenomenon of active material falling off from the current collector surface of the electrode. That is, excessive pressure on the electrode in cell 1 may damage the bonding force between active material particles, resulting in electrode material shedding.

[0027] Cell material loss usually leads to battery capacity decay. That is, the shedding of active material directly reduces the amount of effective material participating in the electrochemical reaction, causing battery capacity decay. For example, the shedding of negative electrode material may cause graphite or silicon-based materials to fall off from the current collector, resulting in loss of active material during charging and discharging, and a gradual decrease in battery capacity.

[0028] In some implementations, reference Figure 3As shown, along the width direction of the pouch battery, the minimum distance between the first overlapping area 230 and the first central axis 101 is L1mm, where L1mm satisfies 5mm≤L1mm≤30mm; and / or, the minimum distance between the second overlapping area 240 and the first central axis 101 is L1mm, where L1mm satisfies 5mm≤L1mm≤30mm.

[0029] By limiting the distance between the first overlapping area 230 and the first central axis 101 in the width direction and / or the distance between the second overlapping area 240 and the first central axis 101 in the width direction, the situation where the first overlapping area 230 and / or the second overlapping area 240 are too close to the first central axis 101, resulting in excessive thickness of the battery cell 1 due to the overlapping area of ​​the tape 2, can be reduced or avoided. It can also reduce or avoid the situation where the first overlapping area 230 and / or the second overlapping area 240 are too far from the first central axis 101, causing the first overlapping area 230 and / or the second overlapping area 240 to be close to the edge of the battery cell 1 and not firmly bonded.

[0030] This can be understood as follows: when the specific size of L1 is lower than the aforementioned minimum value, at least one of the first overlapping area 230 and the second overlapping area 240 will be closer to the first central axis 101. When both the first overlapping area 230 and the second overlapping area 240 are close to the first central axis 101 and their projections in the thickness direction of the soft-pack battery coincide, it will cause the cell 1 to be locally too thick due to the overlap of the tape 2. When the specific size of L1 is higher than the aforementioned maximum value, the first overlapping area 230 and the second overlapping area 240 will be closer to the first central axis 101. At least one of the 40 will be further away from the first central axis 101 and closer to the edge of the cell 1. The multiple cells 1 of the soft-pack battery are usually stacked and then fixed by wrapping with tape 2. When the first overlapping area 230 and the second overlapping area 240 are close to the edge of the cell 1, the tightness of the tape 2 wrapping the multiple cells 1 will also decrease. Therefore, limiting L1 to between 5mm and 30mm can prevent the cells 1 of the soft-pack battery from being too thick in some areas, and can also ensure the tightness of the tape 2 binding the cells 1.

[0031] Furthermore, L1 can be any suitable size within the specified range, such as 5mm, 6mm, 8mm, 10mm, 15mm, 20mm, 30mm, etc., or it can be any suitable size between any two adjacent values.

[0032] In some implementations, reference Figure 3 As shown, on the projection of the plane containing the first sidewall 110 or the second sidewall 120, the first overlapping area 230 and the second overlapping area 240 do not overlap. The distance between the first overlapping area 230 and the second overlapping area 240 in the width direction of the soft pack battery is L2mm, and L2mm satisfies 5mm≤L2mm≤50mm.

[0033] By limiting the distance L2 between the first overlapping area 230 and the second overlapping area 240 in the width direction of the soft-pack battery, the problem of excessive local thickness of the cell 1 can be reduced and the tightness of the tape 2 on the cell 1 can be improved.

[0034] This can be understood as follows: when the specific size of L2 is lower than the minimum value defined above, the distance between the first overlapping area 230 and the second overlapping area 240 on the projection of the thickness direction of the soft-pack battery will decrease, and the two will be too close, which will easily cause the cell 1 to be locally too thick; while when the specific size of L2 is higher than the maximum value defined above, the first overlapping area 230 or the second overlapping area 240 is likely to be located at the edge of the cell 1. Referring to the above embodiment, when the first overlapping area 230 or the second overlapping area 240 is located at the edge of the cell 1, it is easy to reduce the binding stability of the tape 2 to the cell 1. Therefore, limiting L2 to between 5mm and 50mm can reduce or avoid the situation of the cell 1 being locally too thick, and can also improve the binding degree of the tape 2 to the cell 1.

[0035] It should be noted that L2 can be any suitable size within the specified range, such as 5mm, 10mm, 20mm, 30mm, 40mm, 50mm, etc., or it can be any suitable size between any two adjacent values.

[0036] Further, refer to Figure 3 As shown, the length of cell 1 along the width direction of the soft-pack battery is A mm, and L2 / A satisfies 0.35-0.72.

[0037] By limiting the size of L2 / A, the overlapping area of ​​the first overlapping area 230 and the second overlapping area 240 can be ensured to be sufficient to secure the battery cell 1, and the overlapping area will not be too large, so that the first overlapping area 230 and the second overlapping area 240 overlap too much in the thickness direction of the soft pack battery, thus affecting the overall thickness of the battery cell 1.

[0038] In other words, when the value of L2 / A is greater than the maximum value specified above, L2 is relatively too large and A is relatively too small. At this time, the distance between the first overlapping area 230 and the second overlapping area 240 projected in the thickness direction of the soft-pack battery is large, and they are likely to be formed on the side of the cell 1, which can easily reduce the tightness of the tape 2 on the cell 1. When the value of L2 / A is less than the minimum value specified above, L2 is relatively too small and A is relatively too large. At this time, the distance between the first overlapping area 230 and the second overlapping area 240 projected in the thickness direction of the soft-pack battery is small, which can easily cause the first overlapping area 230 and the second overlapping area 240 to overlap in the thickness direction of the soft-pack battery, which can easily increase the local thickness of the cell 1. Therefore, limiting L2 / A to between 0.35 and 0.72 can reduce or prevent the increase in the local thickness of the cell 1 and improve the tightness stability of the tape 2 on the cell 1.

[0039] The specific value of L2 / A can be any suitable value within the above range, such as 0.35, 0.4, 0.5, 0.6, 0.7, 0.72, etc., or it can be any suitable value between any two adjacent values ​​mentioned above.

[0040] Furthermore, the length A of cell 1 along the width direction of the pouch battery should not be too large or too small. If it is too large, the pouch battery will occupy a large volume, and if it is too small, the energy density of cell 1 will be insufficient. Specifically, A can be any suitable length between 70mm and 140mm, such as 70mm, 80mm, 100mm, 120mm, 140mm, etc., or it can be any suitable size between any two adjacent values ​​mentioned above.

[0041] In some implementations, reference Figures 4 to 7 As shown, on the projection of the plane containing the first sidewall 110 or the second sidewall 120, the minimum distance between the first overlapping area 230 and the edge of the cell 1 in the width direction is L3mm, where L3mm satisfies 3mm≤L3mm≤50mm; and / or, the minimum distance between the second overlapping area 240 and the edge of the cell 1 in the width direction is L3mm, where L3mm satisfies 3mm≤L3mm≤50mm.

[0042] By limiting the distance between the first overlapping area 230 and / or the second overlapping area 240 and the sidewall of the battery cell 1 in the width direction, the situation where the first overlapping area 230 and / or the second overlapping area 240 are too close to the edge of the battery cell 1 in the width direction can be avoided more intuitively and clearly, thereby reducing the situation where the tape 2 is not firmly tied to the battery cell 1.

[0043] Furthermore, the specific size of L3 can be any suitable size within the above range, such as 3mm, 5mm, 10mm, 20mm, 30mm, 40mm, 50mm, etc., or any size between any two adjacent values ​​mentioned above.

[0044] In some implementations, reference Figures 3 to 7 As shown, the cell 1 has a dimension of A mm in the width direction of the pouch cell, the first overlapping area 230 has a dimension of L4 mm in the width direction of the pouch cell, and L4 / A satisfies 0.35-0.43; and / or, the second overlapping area 240 has a dimension of L4 mm in the width direction of the pouch cell, and L4 / A satisfies 0.35-0.43.

[0045] By limiting the range of L4 / A as described above, the first overlapping area 230 and / or the second overlapping area 240 can each have sufficient bonding area to ensure the tightness of the tape 2 on the cell 1, and to prevent the overlapping area of ​​the first overlapping area 230 and the second overlapping area 240 from being too large, which would indirectly make the overlapping area of ​​the first overlapping area 230 and the second overlapping area 240 in the thickness direction of the soft pack battery too large, thereby reducing the situation of the cell 1 being too thick in some areas.

[0046] In other words, when the specific size of L4 / A is greater than the maximum value defined above, the first overlapping area 230 and the second overlapping area 240 each have sufficient bonding area. However, in the thickness direction of the pouch battery, the overlapping area of ​​the first overlapping area 230 and the second overlapping area 240 is too large, which can easily cause the cell 1 to be locally too thick. When the specific size of L4 / A is less than the minimum value defined above, in the thickness direction of the pouch battery, the overlapping area of ​​the first overlapping area 230 and the second overlapping area 240 is too small or non-existent, which will not cause the cell 1 to be locally too thick. However, the bonding area of ​​the first overlapping area 230 and the second overlapping area 240 will also be smaller, which will affect the bonding stability of the tape 2 to the cell 1.

[0047] The specific value of L4 / A can be any suitable value within the above range, such as 0.35, 0.36, 0.365, 0.4, 0.43, etc., or it can be any suitable value between any two adjacent values ​​mentioned above.

[0048] Furthermore, the specific size of L4 should not be too large or too small. If it is too large, it will easily cause the area of ​​the first overlapping area 230 and / or the second overlapping area 240 to be too large, resulting in wasted tape length and increased overall battery thickness. If it is too small, it will easily cause the area of ​​the first overlapping area 230 and / or the second overlapping area 240 to be too small, resulting in weak adhesion of tape 2. Specifically, L4 can be any suitable size between 5mm and 30mm, such as 5mm, 6mm, 8mm, 10mm, 20mm, 30mm, etc., or it can be any size between any two adjacent values ​​mentioned above.

[0049] In some implementations, reference Figures 1 to 7 As shown, there can be multiple tapes 2, which are spaced apart along the length of the pouch battery.

[0050] In the above manner, multiple tapes 2 can be arranged at intervals along the length of the soft-pack battery. By simultaneously wrapping the battery cell 1 with multiple tapes 2, the binding effect of the battery cell 1 can be improved.

[0051] Furthermore, refer to Figures 1 to 7 As shown, the battery cell 1 also includes a third sidewall 130 and a fourth sidewall 140. On the projection of the plane containing the third sidewall 130 or the fourth sidewall 140, the tape 2 is attached to the battery cell 1 circumferentially along the third sidewall 130 or the fourth sidewall 140.

[0052] In the above arrangement, that is, the tape 2 is attached to the battery cell 1 circumferentially along the third side wall 130 or the fourth side wall 140, the tape 2 can achieve a more stable binding effect on the battery cell 1.

[0053] When multiple tapes 2 are arranged, you can refer to Figures 1 to 7 As shown, the first overlapping areas 230 of the plurality of tapes 2 at least partially overlap on the projection of the plane containing the third sidewall 130 or the fourth sidewall 140; and / or, the second overlapping areas 240 of the plurality of tapes 2 at least partially overlap on the projection of the plane containing the third sidewall 130 or the fourth sidewall 140.

[0054] Under the above arrangement, the positions of multiple first overlapping areas 230 and / or multiple second overlapping areas 240 can tend to be consistent, thereby improving the stability of the tape 2 binding the battery cell 1.

[0055] Furthermore, on the projection of the plane containing the third sidewall 130 or the fourth sidewall 140, the multiple first overlapping areas 230 on the multiple tapes 2 may or may not overlap. When the multiple first overlapping areas 230 do not overlap, the distance between any two adjacent first overlapping areas 230 in the width direction of the soft-pack battery is L5mm, where L5mm satisfies 1mm≤L5≤10mm; and / or, on the projection plane of the length direction of the soft-pack battery, the multiple second overlapping areas 240 on the multiple tapes 2 may or may not overlap. When the multiple second overlapping areas 240 do not overlap, the distance between any two adjacent second overlapping areas 240 in the width direction of the soft-pack battery is L5mm, where L5mm satisfies 1mm≤L5mm≤10mm.

[0056] By limiting the range of L5, the first overlapping areas 230 and / or the second overlapping areas 240 of the multiple adhesive tapes 2 are not too far apart in the width direction of the soft-pack battery, thus affecting the binding stability of the adhesive tapes 2 to the battery cell 1. In other words, the farther apart the two first overlapping areas 230 and / or the two second overlapping areas 240 are on any two adjacent adhesive tapes 2, the worse the binding stability of the battery cell 1 will be, while the closer the two first overlapping areas 230 and / or the two second overlapping areas 240 are, the better the binding stability of the battery cell 1 will be.

[0057] Furthermore, the specific size of L5 can be any suitable size within the above range, such as 1mm, 2mm, 5mm, 7mm, 10mm, etc., or it can be any suitable size between any two adjacent values ​​mentioned above.

[0058] In some implementations, reference Figures 1 to 7 As shown, the quantity of tape 2 is N, the dimension of tape 2 along the length direction of the soft pack battery is C mm, the dimension of cell 1 along the length direction of the soft pack battery is B mm, and (C×N) / B satisfies 0.1-0.5.

[0059] By limiting the ranges of the length C of the tape 2 along the length of the pouch battery, the length B of the cell 1, and the number N of the tape 2, the spacing between each pair of tapes 2 on the cell 1 can be indirectly controlled. Specifically, when the value of (C×N) / B is less than the minimum value specified above, with the length of the cell 1 remaining constant, the number of tapes 2 decreases, or the length C of the tape 2 along the length of the pouch battery also decreases. This can easily lead to an excessively large area of ​​the cell 1 not constrained by the tapes 2, increasing the risk of cell 1 constraint failure. Conversely, when (C×N) / B is less than the minimum value specified above, the number of tapes 2 decreases, or the length C of the tape 2 along the length of the pouch battery also decreases. This can easily result in an excessively large area of ​​the cell 1 not constrained by the tapes 2, increasing the risk of cell 1 constraint failure. When the value of (C×N) / B is greater than the maximum value specified above, the amount of tape 2 will increase relatively when the length of cell 1 remains unchanged, or the length C of tape 2 in the length direction of the soft-pack battery will also increase relatively. This may lead to an excessive amount of tape 2 being used, resulting in an excessively thickened area for binding cell 1, which may further increase the pressure on cell 1 and cause cell 1 to fall off. Therefore, limiting the value of (C×N) / B to between 0.1 and 0.5 can effectively constrain the tape 2 on cell 1, while also preventing the tape 2 from exerting too much pressure on cell 1.

[0060] Furthermore, the specific size of (C×N) / B can be any suitable size within the range mentioned above, such as 0.1, 0.2, 0.3, 0.4, 0.5, etc., or it can be any size between any two adjacent values ​​mentioned above.

[0061] It should be noted that the length C of the tape 2 in the length direction of the soft-pack battery mentioned in the above embodiments can be referred to as Figure 4 and Figure 5 As shown, C can represent the length of a single tape 2 in the length direction of the soft-pack battery. The length of C should not be too large or too small. If it is too large, the tape 2 will be too wide, which will increase the area of ​​local thickening of the cell 1 and increase the overall space occupied by the soft-pack battery. If it is too small, the tape 2 will not be able to stably bind and fix the cell 1. Specifically, C can be any suitable value between 8mm and 50mm, such as 8mm, 10mm, 20mm, 30mm, 40mm, 50mm, etc., or it can be any suitable size between any two adjacent values ​​mentioned above.

[0062] Further, refer to Figures 4 to 7 As shown, in the length direction of the soft-pack battery, the spacing between any two adjacent tapes 2 is 50mm-150mm.

[0063] By directly limiting the spacing between any two adjacent adhesive tapes 2 along the length of the pouch battery, as described above, it is possible to prevent any two adjacent adhesive tapes 2 from being too close or too far apart along the length of the cell 1. In other words, when the spacing between any two adjacent adhesive tapes 2 is less than the aforementioned minimum value, the spacing between them along the length of the cell 1 is too small, which can easily increase the binding stability of the adhesive tapes 2 on the cell 1. However, it can also increase the local thickness of the adhesive tapes 2 on the cell 1, which can further increase the risk of... The pressure exerted by tape 2 on battery cell 1 can easily cause the battery cell 1 to fall off. When the distance between any two adjacent tapes 2 is greater than the maximum value mentioned above, the distance between any two adjacent tapes 2 in the length direction of battery cell 1 will be too large. Although this reduces the pressure of tape 2 on battery cell 1, it can easily cause the tape 2 to be not firmly bonded to battery cell 1. Therefore, setting the distance between any two adjacent tapes 2 between 50mm and 150mm can both meet the stability of the bonding between tape 2 and battery cell 1 and reduce the pressure of tape 2 on battery cell 1.

[0064] Furthermore, the spacing between any two adjacent tapes 2 can be any suitable size within the range specified above, such as 50mm, 75mm, 100mm, 125mm, 150mm, etc., or any suitable size between any two adjacent values ​​mentioned above.

[0065] In some implementations, reference Figure 3 , Figure 6 and Figure 7 As shown, multiple first overlapping areas 230 are respectively arranged on opposite sides of the first central axis 101; multiple second overlapping areas 240 are respectively arranged on opposite sides of the first central axis 101.

[0066] In the above manner, that is, on the projection plane of the pouch battery along its length, when the multiple first overlapping areas 230 and the multiple second overlapping areas 240 do not overlap, the multiple first overlapping areas 230 can be arranged on opposite sides of the first central axis 101, and the multiple second overlapping areas 240 can also be arranged on opposite sides of the first central axis 101. Under this arrangement, the first overlapping areas 230 and the second overlapping areas 240 can have more selectable layout options. However, when the pouch battery is integrated, the large surfaces of the battery are stacked. When the first overlapping areas 230 and the second overlapping areas 240 of each pouch battery are located in the same position, it will cause the multiple first overlapping areas 230 and the multiple second overlapping areas 240 to overlap with each other after the battery is stacked and integrated, resulting in an increase in the overall space occupied by the pouch battery. Therefore, by arranging the first overlapping areas 230 and the second overlapping areas 240 in a staggered manner according to the above layout method, the overall thickness of the integrated pouch battery can be reduced.

[0067] In some implementations, reference Figures 4 to 7 As shown, the pouch battery also includes a tab 3 connected to the cell 1, and the tab 3 is connected to at least one end of the cell 1 along the length direction of the pouch battery.

[0068] By placing the tab 3 at at least one end along the length of the pouch battery, the pouch battery can be electrically connected to other external conductive components via the tab 3, enabling the pouch battery to function normally.

[0069] It should be noted that the arrangement of the above-mentioned tabs 3 can be any suitable arrangement, for example, as shown in the figure. Figures 4 to 7 As shown, there can be two tabs 3, which can be located at opposite ends of the cell 1. In this arrangement, although the length of the pouch battery is increased, the tabs 3 will generate more heat during normal operation because they are far apart. However, when the tabs 3 are far apart, the heat transfer between them can be reduced or avoided, thus reducing the performance of the pouch battery. Alternatively, the two tabs 3 can be located at the same end of the cell 1. In this arrangement, although the heat transfer between the two tabs 3 during operation is increased, the space occupied by the pouch battery in the length direction can be reduced. Therefore, those skilled in the art can choose any of the above-mentioned tab 3 layout methods according to the actual situation. This embodiment does not limit it further.

[0070] The tab 3 mentioned in the above embodiments can usually be set on one side of the positive current collector or the negative current collector of the pouch battery, and can be separately or integrally formed with the current collector. It is electrically connected to the current collector to conduct the current on the corresponding current collector. The tab 3 can usually be made of a metal material with good conductivity, such as copper, aluminum, nickel and other materials.

[0071] In some implementations, reference Figures 4 to 7 As shown, along the length of the pouch battery, the distance between the tape 2 closest to the tab 3 and the tab 3 is 5mm-80mm.

[0072] By limiting the minimum distance between the tape 2 and the tab 3 as described above, it is possible to prevent or avoid the tape 2 and tab 3 from being too close together, or too far apart. In other words, when the distance between the tape 2 and tab 3 is less than the aforementioned minimum value, the heat generated by the tab 3 during normal operation of the pouch battery can also affect the tape 2. This means the tape 2 is also prone to melting due to the heat generated by the tab 3, which can further damage the battery. The adhesiveness of core 1 deteriorates, resulting in unstable binding effect. When the distance between tape 2 and tab 3 is greater than the maximum value specified above, the distance between tape 2 and tab 3 is too far. In this case, the binding effect of tape 2 on the edge of core 1 in the length direction is easily reduced, and the binding and fixing effect of core 1 is also easily poor. Therefore, limiting the distance between tape 2 and tab 3 to between 5mm and 80mm can satisfy the binding stability of tape 2 on core 1 and prevent the heat generated by tab 3 from affecting tape 2.

[0073] Furthermore, the distance between the tape 2 closest to the tab 3 and the tab 3 can be any suitable size between 5mm and 80mm, such as 5mm, 10mm, 30mm, 60mm, 80mm, etc., or it can be any suitable size between any two adjacent values ​​mentioned above.

[0074] In some implementations, reference Figures 1 to 7 As shown, the thickness of the first tape 210 is 15μm-60μm; and / or, the thickness of the second tape 220 is 15μm-60μm.

[0075] By limiting the thickness of the first tape 210 and / or the second tape 220 as described above, the tape 2 can be prevented from being too thick or too thin. Specifically, when the thickness of the first tape 210 and / or the second tape 220 exceeds the maximum value specified above, it becomes too thick. In this case, when the first tape 210 and the second tape 220 overlap and are used to bind the battery cell 1, it can easily cause significant pressure on the battery cell 1, potentially leading to material loss. Conversely, when the thickness of the first tape 210 and / or the second tape 220 is less than the minimum value specified above, the thickness of the tape 210 and / or the second tape 220 is reduced. If the first tape 210 and / or the second tape 220 are too thin, when the first tape 210 and the second tape 220 overlap and are used to bind the battery cell 1, the strength of the first tape 210 and / or the second tape 220 may be insufficient, i.e. the tape layer may be too thin. This will affect the binding effect of the tape 2 on the battery cell 1, and the tape 2 may also be prone to tearing. Therefore, limiting the thickness of the first tape 210 and / or the second tape 220 to between 15μm and 60μm can satisfy the structural strength of the first tape 210 and / or the second tape 220, and can also reduce or avoid the pressure of the first tape 210 and / or the second tape 220 on the battery cell 1.

[0076] It should be noted that the thickness of the first tape 210 and / or the second tape 220 mentioned in the above embodiments can be referenced. Figure 3 As shown, when the first tape 210 and / or the second tape 220 are attached to the battery cell 1, the side of the first tape 210 and / or the second tape 220 that is closer to the battery cell 1 and faces away from the battery cell 1 on any side wall of the battery cell 1 can be understood as the thickness of the first tape 210 and / or the second tape 220.

[0077] Furthermore, the thickness of the first tape 210 and / or the thickness of the second tape 220 can be any suitable size within the range described above, such as 15μm, 20μm, 30μm, 50μm, 60μm, etc., or any size between any two adjacent values ​​mentioned above.

[0078] 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: The battery cell (1) includes opposing first sidewalls (110) and second sidewalls (120). Adhesive tape (2) is attached to the battery cell (1) around the circumference of the battery cell (1). The adhesive tape (2) includes a first adhesive tape (210) and a second adhesive tape (220). The first end of the first adhesive tape (210) overlaps with the first end of the second adhesive tape (220) on the first sidewall (110) to form a first overlap area (230). The second end of the first adhesive tape (210) overlaps with the second end of the second adhesive tape (220) on the second sidewall (120) to form a second overlap area (240). On the projection of the plane containing the first sidewall (110) or the second sidewall (120), the first overlapping area (230) and the second overlapping area (240) do not overlap each other at least partially.

2. The soft-pack battery according to claim 1, characterized in that, The first sidewall (110) or the second sidewall (120) has a first central axis (101), which extends along the length direction of the pouch battery and bisects the first sidewall (110) or the second sidewall (120) along the width direction of the pouch battery. The first central axis (101) is projected onto the plane where the first sidewall (110) or the second sidewall (120) is located. The first overlapping area (230) and the second overlapping area (240) are located on opposite sides of the first central axis (101).

3. The soft-pack battery according to claim 2, characterized in that, Along the width direction of the pouch battery, the minimum distance between the first overlapping area (230) and the first central axis (101) is L1mm, wherein L1mm satisfies 5mm≤L1mm≤30mm; and / or, The minimum distance between the second overlapping area (240) and the first central axis (101) is L1mm, and L1mm satisfies 5mm≤L1mm≤30mm.

4. The soft-pack battery according to claim 1, characterized in that, On the projection of the plane containing the first sidewall (110) or the second sidewall (120), the first overlapping area (230) and the second overlapping area (240) do not overlap. The distance between the first overlapping area (230) and the second overlapping area (240) in the width direction of the soft pack battery is L2mm, and L2mm satisfies 5mm≤L2mm≤50mm.

5. The soft-pack battery according to claim 4, characterized in that, The length of the cell (1) along the width direction of the soft-pack battery is A mm, and L2 / A satisfies 0.35-0.

72.

6. The soft-pack battery according to claim 1, characterized in that, On the projection of the plane containing the first sidewall (110) or the second sidewall (120), the minimum distance between the first overlapping area (230) and the edge of the cell (1) in the width direction is L3mm, wherein L3mm satisfies 3mm≤L3mm≤50mm; and / or, The minimum distance between the second overlapping area (240) and the edge of the cell (1) in the width direction is L3mm, and L3mm satisfies 3mm≤L3mm≤50mm.

7. The soft-pack battery according to claim 1, characterized in that, The cell (1) has a dimension of A mm in the width direction of the pouch cell, and the first overlapping area (230) has a dimension of L4 mm in the width direction of the pouch cell, where L4 / A satisfies 0.35-0.43; and / or, The second overlapping area (240) has a dimension of L4mm in the width direction of the soft-pack battery, and L4 / A satisfies 0.35-0.

43.

8. The soft-pack battery according to claim 2, characterized in that, The number of tapes (2) is multiple and they are arranged at intervals along the length direction of the soft-pack battery.

9. The soft-pack battery according to claim 8, characterized in that, The battery cell (1) also includes a third sidewall (130) and a fourth sidewall (140) opposite each other. On the projection of the plane where the third sidewall (130) or the fourth sidewall (140) is located, the tape (2) is attached to the battery cell (1) circumferentially along the third sidewall (130) or the fourth sidewall (140). The first overlapping areas (230) of the plurality of tapes (2) at least partially overlap on the projection of the plane containing the third sidewall (130) or the fourth sidewall (140); and / or, The second overlapping areas (240) of the plurality of tapes (2) at least partially overlap on the projection of the plane containing the third sidewall (130) or the fourth sidewall (140).

10. The soft-pack battery according to claim 9, characterized in that, The distance between any two adjacent first overlapping regions (230) in the width direction of the pouch battery is L5mm, where L5mm satisfies 1mm≤L5mm≤10mm; and / or, The distance between any two adjacent second overlapping regions (240) in the width direction of the soft-pack battery is L5mm, wherein L5mm satisfies 1mm≤L5mm≤10mm.

11. The soft-pack battery according to claim 8, characterized in that, The quantity of the tape (2) is N, the dimension of the tape (2) along the length direction of the soft pack battery is C mm, the dimension of the cell (1) along the length direction of the soft pack battery is B mm, and (C×N) / B satisfies 0.1-0.

5.

12. The soft-pack battery according to claim 8, characterized in that, Along the length of the soft-pack battery, the spacing between any two adjacent tapes (2) is 50mm-150mm.

13. The soft-pack battery according to claim 8, characterized in that, Multiple first overlapping regions (230) are respectively arranged on opposite sides of the first central axis (101); multiple second overlapping regions (240) are respectively arranged on opposite sides of the first central axis (101).

14. The soft-pack battery according to claim 1, characterized in that, The pouch battery also includes a tab (3) connected to the cell (1), and the tab (3) is connected to at least one end of the cell (1) along the length direction of the pouch battery.

15. The soft-pack battery according to claim 14, characterized in that, Along the length of the soft-pack battery, the distance between the tape (2) closest to the tab (3) and the tab (3) is 5mm-80mm.

16. The soft-pack battery according to claim 1, characterized in that, The thickness of the first tape (210) is 15μm-60μm; and / or the thickness of the second tape (220) is 15μm-60μm.

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