Battery

Abstract

Battery characterized in that it comprises the following: a housing (1) wherein a pole column assembly (31) is provided on the housing (1); a winding cell (2), wherein the winding cell (2) comprises a winding cell body (222) and comprising several pole vanes (221); and wherein the pole vanes (221) are designed for electrical connection with the pole column assembly (31) or with the housing (1); wherein in the unfolded state of the winding cell (2) along the longitudinal direction of the winding cell (2); the difference between the maximum thickness and the minimum thickness of the winding cell body (222) is d and the unit of d is mm, and where the number of winding layers of the winding cell body (222) is n, where the condition is satisfied: 0.08 ≤ d · n ≤ 0.9 and n ≤ 200.

Description

Technical area

[0001] The present application relates to the technical field of batteries and in particular to a battery. Background technology

[0002] In the prior art, battery cells are often electrically connected to the terminals via the terminal tabs, or the terminals and terminals are electrically connected via an adapter plate. Using the direct electrical connection between the terminals and the terminals as an example, several terminal tabs are cut from the edge of one end of the terminal plate during battery cell manufacturing. After the terminal plate is wound, the terminal tabs are flattened at the appropriate points to facilitate the electrical connection with the terminals.

[0003] However, since the pole sheet contains a current collector and an active material layer, the active material is shaped on the current collector by a rolling process after application, resulting in an uneven thickness of the pole sheet. This leads to an increase in the gap between the front layer and the rear layer after winding, and then causes poor alignment of the terminals in the radial direction of the battery cell. This results in a reduction of the subsequent solder area of ​​the terminals and pole columns, and thus in insufficient overcurrent capacity. Contents of the utility model

[0004] In light of this, the present application provides a battery that solves the problem of insufficient overcurrent capacity caused by poor alignment of the terminals in the radial direction of the battery cell. The present application provides a battery comprising the following: a housing, wherein a pole column assembly is provided on the housing; a cylindrical winding cell, wherein the cylindrical winding cell comprises a winding cell body and several pole tabs extending from the winding cell body; wherein the pole tabs are designed for electrical connection with the pole column assembly or the housing; and wherein the several pole tabs are distributed in several layers along the radial direction of the winding cell body; wherein, when the cylindrical winding cell is in the unfolded state, the width of a single pole vane along the longitudinal direction of the cylindrical winding cell is E, provided that the condition is met: 2 mm ≤ E ≤ 9 mm; where the difference between the maximum thickness and the minimum thickness of the winding cell body is d and the number of winding layers of the winding cell body is n, where the condition is satisfied: 0.08 ≤ d · n ≤ 0.9. Beneficial effects:

[0005] The battery provided by the embodiment of the present application achieves better alignment of the terminals by controlling the ratio between the number of winding layers and the thickness difference of the cell body. This ensures that the terminals subsequently have sufficient soldering surface area and guarantees the overcurrent capacity. Furthermore, by limiting the width E of a single terminal to 2 mm ≤ E ≤ 9 mm, each terminal becomes a smaller terminal with a narrower width. Since the cylindrical cell has multiple terminals extending from the cell body, cutting slots are arranged between adjacent terminals to allow the multiple terminals to overlap after winding the cylindrical cell, thereby forming a terminal area and ensuring sufficient soldering surface area.If a single large pole tab were used, it would easily wrinkle or even fold during the winding of the cylindrical winding cell, hindering the provision of a sufficient soldering surface. Therefore, a large pole tab is cut into several smaller pole tabs by arranging cutting slots to prevent wrinkling during the winding process. However, due to the thickness difference of the pole sheet, the pole tabs tend to be layer-shifted during winding. Simultaneously, the use of small pole tabs creates a gap between adjacent individual pole tabs in the circumferential direction of the cylindrical winding cell, increasing the risk of layer misalignment. Thus, the ratio between the thickness difference d and the number of winding layers n must be strictly controlled to avoid serious layer misalignment and the occurrence of inadequate subsequent electrical contact surfaces. Figures

[0006] To more clearly illustrate the specific embodiments of the present application and the technical solutions in the prior art, the figures necessary for use in the specific embodiments and the description of the prior art are briefly presented below. Obviously, the figures described below represent some embodiments of the present application, and general technical personnel in this field can draw further figures based on these without any creative effort. Fig. Figure 1 is a schematic representation of the battery of the present application; Fig. Figure 2 is a schematic exploded view of the battery of the present application; Fig. 3 is a schematic representation of the cylindrical winding cell of the present application in top view; Fig. Figure 4 is a schematic representation of the pole plate of the present application in its unfolded state; Fig. Figure 5 is a schematic representation of a multi-point measurement of the pole plate of the present application in the unfolded state; Fig. Figure 6 is a schematic representation of section AA in Fig. 5; Fig. Figure 7 is a schematic representation of another pole plate of the present application in its unfolded state.

[0007] Reference symbols in the figures: 1. Housing; 2. Cylindrical winding cell; 21. Pole vane area; 22. Pole plate; 221. Pole vane; 222. Winding cell body; 223. Single-layer pole vane group; 224. Thinning area; 3. Cover plate; 31. Pole column assembly; 32. Adapter plate. Specific embodiments

[0008] To clarify the purpose, technical solution, and advantages of the embodiments of the present application, the technical solutions in the embodiments of the present application are described below in detail in conjunction with the attached drawings. It is obvious that the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments of the present application, all further embodiments that a person skilled in the art obtains without creative activity fall within the scope of protection of the present application. In the description of the present application, it should be understood that azimuth or positional relationships relating to the terms "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inside," "outside," etc., are not included.The terms "first", "second", and "third" refer to azimuth or positional relationships based on the figures. They are intended to facilitate and simplify the description of the present application, rather than indicating or implying that the device or component in question must have a specific orientation, be constructed in a specific orientation, and be operated in a specific orientation. Therefore, they must not be understood as limiting the present application. Furthermore, the terms "first", "second", and "third" are used only for differentiated description and cannot be understood as indicating a relative meaning.

[0009] In the description of this application, it should be noted that the terms "install," "connect," and "link" are to be understood in a broad sense unless expressly stated otherwise or limited. For example, it may be a permanent connection, a detachable connection, or a connection in one piece; it may be a mechanical connection or an electrical connection; it may be a direct connection, an indirect connection via an intermediate medium, or a connection within the two elements. For general technical personnel in this field, the specific meaning of the above terms in this application may be understood according to the specific circumstances.

[0010] Furthermore, the various features described below can be combined in the embodiments of the present application as long as they do not conflict with each other.

[0011] In related techniques, the battery cells are often electrically connected to the terminals via the terminal tabs, or the terminals and terminals are electrically connected via an adapter plate. Using the direct electrical connection between the terminals and the terminals as an example, several terminal tabs are cut from the edge of one end of the terminal plate during the battery cell preparation phase. After the terminal plate is wound, the terminal tabs are flattened at the appropriate points so that they overlap within the plate, forming a terminal soldering area suitable for soldering to the terminals.

[0012] If the terminal strip is ideally and uniformly distributed after winding, the area of ​​the terminal soldering area can be effectively ensured. However, since the terminal strip comprises a current collector and an active material layer, the active material is applied to the current collector and shaped by a rolling process. This can lead to uneven thickness of the terminal strip, increasing the gap between the front and back layers after winding. This results in poor alignment of the terminals radially within the battery cell, excessive overlap of the terminals, and a reduction in the effective area of ​​the terminal soldering area. In other words, the subsequent soldering area of ​​the terminals and the terminal column is reduced, easily leading to insufficient overcurrent capacity.

[0013] The battery provided by the embodiment of the present application achieves better alignment of the terminals by controlling the ratio between the number of winding layers and the thickness difference of the winding cell body 222, thereby ensuring that the terminals subsequently have sufficient soldering area and that the overcurrent capacity is ensured. Embodiments of the present application are described below with reference to the Fig. 1 to 7 described.

[0014] According to the embodiments of the present application, a battery is provided comprising the following: a housing 1, wherein the housing 1 is provided with a pole column assembly 31; a cylindrical winding cell 2, wherein the cylindrical winding cell 2 comprises a winding cell body 222 and several pole tabs 221; wherein the pole tabs 221 are designed for electrical connection with the pole column assembly 31 or the housing 1; wherein the several pole tabs 221 are distributed in several layers along the radial direction of the winding cell body 222; wherein, when the cylindrical winding cell 2 is in the unfolded state, the width of a single pole vane 221 along the longitudinal direction of the cylindrical winding cell 2 is E, provided that the condition is met: 2 mm ≤ E ≤ 9 mm; where the difference between the maximum thickness and the minimum thickness of the coiled cell body is 222 d and the number of winding layers of the coiled cell body is 222 n, where the condition is satisfied: 0.08 ≤ d · n ≤ 0.9.

[0015] The cylindrical winding cell 2 has a cylindrical structure, and the housing 1 is attached to the outside of the cylindrical winding cell 2. In this embodiment, the structure of the housing 1 is not limited and can be cylindrical or hexagonal, as long as the cylindrical winding cell 2 can be placed and held in the housing 1.

[0016] The housing 1 includes a pole column assembly 31 and the pole column assembly 31 is designed for subsequent electrical connection with other structures, for example with a busbar, to supply current.

[0017] The housing 1 comprises a housing body and a cover plate 3, and the pole column assembly 31 can be arranged on the housing body or on the cover plate 3.

[0018] The winding cell body 222 is formed by winding the pole sheet. In this embodiment, the winding cell body 222 refers in particular to the fact that, in the unfolded state, the area with the exception of the thinning area 224 is removed along the width direction of the pole sheet.

[0019] The width of a single pole vane 221 refers to the width of the single pole vane 221 along the longitudinal direction of the cylindrical winding cell 2 when the cylindrical winding cell 2 is in the unfolded state. During the measurement, the winding cell body 222 may be flattened, and at this time the dimension of the pole vane 221, measured along the longitudinal direction of the pole sheet, is the width of the pole vane 221.

[0020] The structure of a single polar flag 221 can vary, for example rectangular (as in Fig. 4 shown), trapezoidal (as in Fig. 7 shown) or in another special form.

[0021] Since the structural shapes of individual pole vanes 221 differ, there are differences in the measurement methods for the width E of individual pole vanes 221: If the individual pole vane is rectangular, this refers to the dimension of the cylindrical winding cell 2 in the longitudinal direction when the cylindrical winding cell 2 is in the unfolded state; if the individual pole vane is trapezoidal, this refers to the maximum dimension of the cylindrical winding cell 2 in the longitudinal direction when the cylindrical winding cell 2 is in the unfolded state.

[0022] The battery provided by the embodiment of the present application achieves better alignment of the terminals by controlling the ratio between the number of winding layers and the thickness difference of the winding cell body 222. This ensures that the terminals subsequently have sufficient soldering surface area and that the overcurrent capacity is guaranteed. Furthermore, by limiting the width E of an individual terminal 221 to 2 mm ≤ E ≤ 9 mm, each terminal 221 becomes a smaller terminal with a narrower width. Since the cylindrical winding cell 2 has several terminals 221 extending from the winding cell body 222, cutting slots are arranged between adjacent terminals 221 to allow the multiple terminals 221 to overlap after the cylindrical winding cell 2 is wound, thereby forming a terminal area 21 and ensuring sufficient soldering surface area.If a single large pole tab were used, it would easily wrinkle or even fold during the winding of the cylindrical winding cell 2, hindering the guarantee of a sufficient soldering surface. Therefore, a large pole tab is cut into several smaller pole tabs by arranging cutting slots to prevent wrinkling during the winding process. However, due to the thickness difference of the pole sheet, the pole tabs tend to become layer-shifted during winding. Simultaneously, the use of smaller pole tabs creates a gap between them, increasing the risk of layer misalignment. Thus, the ratio between the thickness difference d and the number of winding layers n must be strictly controlled to avoid serious layer misalignment and the occurrence of insufficient subsequent electrical contact surfaces.

[0023] In this embodiment, the width E of a single pole vane 221 can be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 8 mm, 9 mm, etc.

[0024] In this embodiment, an opening is formed on one side of the housing 1 along the axial direction, the cover plate 3 is arranged on the opening of the housing 1, and the cylindrical winding cell 2 is arranged in the housing 1. Alternatively, openings can also be formed on both sides of the housing 1 along the axial direction, and the cover plate 3 can be arranged on the openings of the housing 1.

[0025] The cylindrical winding cell 2 comprises a pole plate 22, which can in particular be subdivided into a cathode plate and an anode plate, and the cylindrical winding cell 2 is formed by stacking the cathode plate and the anode plate as well as the separator and subsequently winding these.

[0026] After the cylindrical winding cell 2 is wound, several pole tabs 221 are stacked to form a pole tab area 21, and the pole tab area 21 is designed for electrical connection with the pole column assembly 31 or the housing 1; this conducts the current from the cylindrical winding cell 2 outwards from the battery.

[0027] The polar column assembly 31 comprises a polar column and an adapter plate 32, wherein one side of the adapter plate 32 is fixedly connected to the polar column and the other side of the adapter plate 32 is connected to the polar vane area 21.

[0028] In this embodiment, the pole plate 22 comprises several pole vanes 221 and is wound into a winding cell, with each layer of the winding cell comprising several pole vanes 221 and the multiple pole vanes 221 located in the pole vane region 21 of the same layer of the winding cell forming a single-layer pole vane group 223. With a uniform thickness consistency of the pole plate, after winding the cylindrical winding cell 2, the gap between the radial layers is uniform, and the adjacent single-layer pole vane groups 223 are well aligned, thus effectively ensuring the effective area of ​​the pole vane region 21 and, consequently, the soldering surface of the pole vane region 21 with the pole column. However, if the thickness of the pole plate is uneven, i.e., if the difference between the maximum thickness and the minimum thickness of the winding cell body 222 is large, the alignment of the single-layer pole vane groups 223 adjacent along the radial direction is poor.If the number of winding layers is relatively large, the layer misalignment of the terminals is further exacerbated, which can easily lead to an insufficient effective area of ​​the terminal region 21, a reduction in the solder area between the terminal region 21 and the terminal column, and a potential insufficient overcurrent capacitance. The alignment of the terminals in the radial direction of the winding cell can be ensured as far as possible by comprehensively controlling the relationship between the difference d between the maximum and minimum thickness of the winding cell body 222 and the number n of winding layers of the winding cell 2, thereby effectively reducing the occurrence of a misaligned terminal orientation.

[0029] If d · n is too large, i.e., if the difference between the maximum and minimum thickness of the wound cell body 222 is large, or if the number of winding layers is large, or if both are present, poor alignment of the terminal tabs in the radial direction of the battery cell can easily occur. This leads to a reduction in the solder area of ​​the terminal tab region 21 and the terminal column, and can easily result in insufficient overcurrent capacity. If d · n is too small and the difference between the maximum and minimum thickness of the wound cell body 222 is small, strict control conditions are required for the production process, the process is difficult to implement, and production costs increase significantly. A small number of winding layers easily leads to a low energy density of the battery.The terminal plate 22 comprises a cathode plate and an anode plate; the cathode plate comprises a cathode current collector and a cathode active material layer, and the anode plate comprises an anode current collector and an anode active material layer. There is no particular restriction regarding the cathode current collector, as long as it is conductive and does not cause adverse chemical changes in the battery. For example, stainless steel, aluminum, nickel, titanium, burnt carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., may be used. Regarding the anode current collector, copper, stainless steel, nickel, titanium, etc., may be used; in a specific embodiment, the cathode current collector may be made of aluminum and the anode current collector of copper.

[0030] The cathode active material layer comprises cathode active materials, and cathode active materials include ternary nickel-cobalt-manganese materials, lithium iron phosphate materials, lithium manganese iron phosphate materials, etc.; the anode active material layer comprises anode active materials, and anode active materials include synthetic graphite, natural graphite, silicon-based materials, etc.

[0031] The active material is applied to the current collector and shaped on the current collector by a rolling process, which can result in an uneven thickness of the winding cell body 222. To determine the thickness of the winding cell body 222, and thus its maximum and minimum thickness, the winding cell body 222 can be flattened during a special measurement process. A specific area of ​​the middle region, the first region, and the last region (as in region X1, region X2, and region X3 in [reference missing]) is measured. Fig. 5 shown) and several measurements are taken (as in Fig. Figure 5 shows that the circles within areas X1, X2, and X3 represent randomly selected measurement points to determine the maximum and minimum thickness of each of these areas (as shown in Figure 5). Fig. As shown in Figure 6, the maximum thickness in region X1 is d1 and the minimum thickness is d2; subsequently, the minimum thickness is subtracted from the maximum thickness in these regions to obtain the difference d between the maximum and minimum thickness of the winding cell body 222. In particular, in this embodiment, the area of ​​the middle region, the first region, and the last region can be 2500 mm². 2 The number of measuring points is determined by random selection in each of the middle areas, the middle range, and the last range.

[0032] In some embodiments, several polar flags 221 are provided on the same layer.

[0033] Several means greater than or equal to two.

[0034] Since the cylindrical winding cell 2 has several pole tabs 221 extending from the winding cell body 222, cutting slots are arranged between adjacent pole tabs 221 to allow the multiple pole tabs 221 to overlap after the cylindrical winding cell 2 is wound, thereby forming a pole tab area 21 and ensuring a sufficient soldering surface. At the same time, a gap is created between the pole tabs, which increases the risk of layer misalignment. Therefore, the ratio between the thickness difference d and the number of winding layers n must be strictly controlled to avoid serious layer misalignment.

[0035] In some embodiments, the difference d between the maximum thickness and the minimum thickness of the winding cell body 222 satisfies the condition: 0.002mm ≤ d ≤ 0.012mm.

[0036] In this embodiment, the difference d between the maximum thickness and the minimum thickness of the winding cell body 222 can be, in particular, 0.002 mm, 0.005 mm, 0.008 mm, 0.010 mm, 0.011 mm, 0.012 mm, etc.

[0037] By controlling the difference d between the maximum thickness and the minimum thickness of the winding cell body 222, the gap between the radial layers is uniform after winding the cylindrical winding cell 2, which ensures good alignment of the pole tabs, thus ensuring that the pole tabs later have sufficient soldering area and that the overcurrent capacity is ensured.

[0038] If the difference d between the maximum and minimum thickness of the wound cell body 222 exceeds the upper limit, the thickness consistency of the wound cell body 222 is poor, which increases the gap between the front and rear layers after winding. This leads to poor alignment of the terminal tabs in the radial direction of the battery cell, excessive overlap areas between the terminal tabs 221, and a reduction in the effective area of ​​the terminal tab area 21. That is, the subsequent solder area of ​​the terminal tabs 21 and the terminal tab solder area is reduced, which easily leads to insufficient overcurrent capacity.

[0039] If the difference d between the maximum thickness and the minimum thickness of the winding cell body 222 exceeds the lower limit, strict control conditions are required for the production process, making the process difficult to implement and significantly increasing production costs.

[0040] In some embodiments, the dimension of the polar vane 221 along the radial direction H is satisfied, provided that the condition is: 240 ≤ H / d ≤ 5000.

[0041] The smaller the dimension H of the pole vane 221 along the radial direction, the stricter the precision requirements between the offset layers, and with a smaller dimension H of the pole vane 221 along the radial direction, the overcurrent cross-section is smaller. In this case, the difference d must be smaller to ensure consistency of the pole sheet thickness and thus reduce the risk of subsequent offset layers and avoid insufficient overcurrent. In some embodiments, the pole vane 221 comprises a positive pole vane and a negative pole vane, and the positive and negative pole vanes are located on the same side of the winding cell body 222 along the axial direction; one of the positive and negative pole vanes is electrically connected to the pole column assembly 31, and the other is electrically connected to the housing 1 and satisfies the condition: 0.12 ≤ d · n ≤ 0.8.

[0042] The positive and negative terminals are located along the axial direction on the same side of the coiled cell body 222. Because the positive and negative terminals exit on the same side, the pole column and the housing 1 serve as the output terminals and are each electrically connected to the positive and negative terminals, respectively. This shortens the current path for subsequent electrical connections and reduces the impedance. If the positive and negative terminals exit on opposite sides, the current path for one terminal must pass through the housing, resulting in a longer current path and higher impedance.

[0043] Since the positive terminal and the negative terminal are located along the axial direction on the same side of the winding cell body 222, the positive terminal and the negative terminal together must occupy the area of ​​the end face of the same side of the winding cell body 222, which reduces the area for each terminal so that the range of d · n is preferably 0.12 ≤ d · n ≤ 0.8; this ensures the alignment of the terminals and ensures that the terminals subsequently have sufficient soldering area and that the overcurrent capacitance is ensured.

[0044] In some embodiments, the diameter of the cylindrical winding cell is 2D, where the condition is met: 40 mm ≤ D ≤ 56 mm.

[0045] If the positive terminal and the negative terminal are located on the same side of the winding cell body 222 along the axial direction, the positional offset of the terminals worsens the insufficient overcurrent capacity of the positive and negative terminals, so the diameter of the cylindrical winding cell 2 must be chosen to be larger in order to increase the area of ​​the respective adjustment ranges of the positive and negative terminals and thus ensure the overcurrent capacity.

[0046] In this embodiment, the diameter D of the cylindrical winding cell 2 can be 40 mm, 42 mm, 45 mm, 47 mm, 49 mm, 50 mm, 52 mm, 56 mm, etc.

[0047] In some embodiments, the dimension of the pole flag 221 along the radial direction is H and the diameter of the cylindrical winding cell 2 is D, where the condition is met: 0.05 ≤ H / D ≤ 0.25.

[0048] It should be noted that when measuring the dimension H of the pole vane 221 along the radial direction, this can be the distance from the end of the pole vane 221 facing the winding cell body 222 to the end facing away from the winding cell body 222 along the width direction of the winding cell after the cylindrical winding cell 2 has been unfolded.

[0049] When the positive and negative terminal tabs are fed from the same side, they share the same battery cell end face, and their respective overcurrent areas are relatively small. Therefore, the H / D ratio must be controlled. H / D must not be too small, as this would require more layers of terminal tabs, increasing the subsequent risk of layer misalignment. Furthermore, H / D must not be too large, as this would increase the radial dimension of the terminal tabs and the risk of tab folding during winding. Because the positive and negative terminal tabs are on the same side and their radial dimension is too long, the positive and negative terminal tabs in the innermost layer, closest to the center of the wound cell, tend to overlap, creating a risk of short circuits.Further explanation for the overlap between the positive and negative pole flags: Since the pole flags initially stand vertically, they flatten and fold back onto their end faces. If the pole flags are too long, the risk of overlap between the positive and negative pole flags, which lie at the innermost point, increases.

[0050] In some embodiments, the pole vane 221 is rectangular and meets the condition: 0.002 mm ≤ d ≤ 0.008 mm; or the shape of the polar vane 221 is trapezoidal and meets the condition: 0.002 mm ≤ d ≤ 0.01 mm.

[0051] If the polar vane 221 is rectangular, the gap between the polar vanes in the same position is larger, and the probability of a subsequent displacement deviation is greater, so the range of d must be smaller. If the polar vane 221 is trapezoidal, the gap between the polar vanes in the same position is smaller, and the probability of a subsequent displacement deviation is lower, so the range of d can be somewhat larger.

[0052] In some embodiments, several terminal tabs 221 are stacked to form a terminal tab area 21. Along the radial direction, the terminal tab area 21 is fan-shaped and fulfills the condition: 0.003 mm ≤ d ≤ 0.012 mm. The terminal tab area 21 is fan-shaped and can be easily adapted to the shape of the battery cell. By stacking several terminal tabs 221 to form the terminal tab area 21, the risk of terminal tab misalignment can be reduced and the permissible range of d can be increased.

[0053] Furthermore, the range of d in this embodiment can preferably be as follows: 0.003 mm ≤ d ≤ 0.0085 mm.

[0054] Furthermore, the range of d in this embodiment can preferably be as follows: 0.0035 mm ≤ d ≤ 0.011 mm.

[0055] In some other embodiments, the pole flag 221 comprises a positive pole flag and a negative pole flag, and the positive pole flag and the negative pole flag are each located on both sides of the winding cell body 222 along the axial direction; the dimension of the pole flag 221 along the radial direction is H and the diameter of the cylindrical winding cell 2 is D, wherein the condition is satisfied: 0.03 ≤ H / D ≤ 0.2.

[0056] In this embodiment, the positive and negative terminal tabs are located on opposite sides of the wound cell body 222 along the axial direction; that is, the positive and negative terminal tabs are located on opposite sides, so that the positive and negative terminal tabs do not have to jointly occupy the area of ​​the end face of the same side of the wound cell body 222. This ensures that the area allocated for the positive and negative terminal tabs is increased and that the H / D ratio can be set relatively small to reduce the dimension of the overlapping terminal tabs between adjacent layers and thus avoid the situation where the terminal tab area is too thick after folding. During battery cell processing, the terminal tabs are first cut out of the terminal sheet, initially standing upright and then folded back.If H is too large, the overlap of the terminal tabs increases after folding, resulting in a greater terminal thickness of the battery assembly. Furthermore, the risk of creasing increases when winding the terminal tabs.

[0057] In some embodiments, the pole vane 221 is rectangular and meets the condition: 0.003 mm ≤ d ≤ 0.0085 mm; or the polar vane 221 is trapezoidal and meets the condition: 0.0035 mm ≤ d ≤ 0.011 mm.

[0058] Since the positive and negative terminals can be arranged on different end faces of the battery cell, the positive and negative terminal areas can be chosen to be larger. Therefore, in the solution where the positive and negative terminals extend from different sides, compared to the solution where the positive and negative terminals extend from the same side, the difference d between the maximum thickness and the minimum thickness of the wound cell body 222 can be increased accordingly to reduce the limitations of the process conditions during terminal sheet processing and to improve production efficiency.

[0059] In some embodiments, along the radial direction the difference between the number of polar vanes 221 in the outermost position and the number of polar vanes 221 in the innermost position is m, where the condition is met: m is greater than or equal to 3; and also: 0.002 mm ≤ d ≤ 0.01 mm.

[0060] Due to the thickness difference d, the pole tabs of different winding layers may be offset after completion of the winding process. If m is relatively small, for example 1 or 2, the risk of a general layer misalignment of the pole tabs after completion of the winding process is relatively low. If the difference m between the number of pole tabs 221 in the outermost layer and the number of pole tabs 221 in the innermost layer is relatively large, for example, if m is greater than or equal to 3, the risk of layer misalignment increases after completion of the winding process, resulting in a larger circumferential distance between the outermost pole tab and the innermost pole tab; the soldering of the pole tabs and the pole column assembly relies mainly on soldering the central region together.If the risk of layer misalignment increases, the effective soldering area decreases, leading to overcurrent; therefore, it is necessary to control the value range of d more precisely in order to further reduce the risk of layer misalignment.

[0061] Furthermore, the difference between the number of polar flags 221 in the outermost position and the number of polar flags 221 in the innermost position is m, where the condition is met: m is less than or equal to 8.

[0062] By limiting the upper limit of m to avoid too many layers, the thickness difference of the pole sheet must be limited too strictly, leading to overly strict pole sheet processing conditions.

[0063] In some embodiments, such as in Fig. As shown in Figure 3, the angle A enclosed along the radial direction between the connecting lines from the pole vane (221) in the outermost position and the pole vane (221) in the innermost position to the axis center of the winding cell (2) is given by the angle A, where the condition is met: 0° < A ≤ 18°.

[0064] It should be noted that the terms "polar flag in the outermost position" and "polar flag in the innermost position" refer, respectively, to the outermost and innermost marginal polar flags along the radial direction.

[0065] By limiting the angle enclosed between the connecting lines from the pole flag in the outermost position or the pole flag in the innermost position to the axis center of the winding cell 2, the distance of the layer offset of the pole flags within a certain range is controlled in order to avoid subsequent effects on the overcurrent area of ​​the pole flags.

[0066] In some embodiments, the thickness of the winding cell body is 222 C, where the condition is met: C≥0.080 mm; and also: 0.12 ≤ d · n ≤ 0.8.

[0067] If the thickness C of the winding cell body 222 ≥ 0.080 mm, the thickness of the winding cell body 222 is relatively large. After winding the cylindrical winding cell 2, the gap between the layers along the radial direction is relatively large, which increases the risk of layer misalignment of the pole vanes and worsens the alignment of the adjacent single-layer pole vane groups 223 along the radial direction, so a smaller value of d · n is required.

[0068] Furthermore, with a relatively large thickness, it is more difficult to control the consistency of the pole sheet thickness during the rolling process.

[0069] In some embodiments, the cylindrical winding cell 2 comprises a thinning area 224 and the difference between the maximum thickness and the minimum thickness of the cylindrical winding cell 2 in the thinning area 224 is F, where the condition is met: 8µm ≤ F ≤ 60µm.

[0070] As in Fig. As shown in Figure 6, the thinning areas 224 refer to certain regions in the coating of the terminal sheet 22 where the coating material is thinner than in other regions, thus forming a gradient distribution structure. The thickness of the thinning area is one of the important parameters that influence battery performance. First, thinning the terminal sheet can reduce the battery's internal resistance, thereby improving discharge performance and charging speed. Second, appropriate thinning can increase the specific surface area of ​​the cathode sheet, improving the contact area between the electrode material and the electrolyte, thus increasing the battery's energy density and lifespan. However, excessive thinning of the thinning area can also reduce the mechanical strength of the terminal sheet, thereby increasing safety risks for the battery.

[0071] Since the thinning area is located closer to the base of the pole flag, the pole flag is then subjected to a folding process starting from a position near the root, and large thickness differences in the thinning area can increase the risk of pole flag misalignment between different layers. If the difference F between the maximum and minimum thickness of the winding cell body 222 in the thinning area exceeds the upper limit, the thickness consistency of the winding cell body 222 in the thinning area is poor, resulting in individual pole flags and the preceding pole flags not being distributed along the radial direction. This increases the degree of layer misalignment of the pole flags and reduces the effective area of ​​the pole flag area 21, i.e., the subsequent solder area of ​​the pole flag area 21 and the pole column is reduced, which can easily lead to insufficient overcurrent capacity.

[0072] If the difference F between the maximum thickness and the minimum thickness of the thinning area 222 exceeds the lower limit, strict control conditions are required for the production process, making the process difficult to implement and significantly increasing production costs.

[0073] In some embodiments, the number n of winding layers of the cylindrical winding cell 2 satisfies the condition: n ≤ 200.

[0074] If the number of winding layers n on the cylindrical winding cell 2 exceeds the upper limit, the number of winding layers is relatively large. The accumulation of defects further increases the layer misalignment of the terminal tabs, which can lead to an insufficient effective area in the terminal tab region 21. This reduces the solder area between the terminal tab region 21 and the terminal column, resulting in insufficient overcurrent capacity. If the number of winding layers n on the cylindrical winding cell 2 exceeds the lower limit, the energy density of the battery is likely to be low.

[0075] In some embodiments, such as in Fig.As shown in Figure 3, the cylindrical winding cell 2 comprises a cathode plate and an anode plate. After winding the cylindrical winding cell 2, the multiple pole tabs 221 of the cathode plate are stacked to form a positive pole tab region, and the multiple pole tabs 221 of the anode plate are stacked to form a negative pole tab region, wherein the positive pole tab region and the negative pole tab region are located along the axial direction on the same side of the cylindrical winding cell 2 and the positive pole tab region and the negative pole tab region are spaced apart from each other.

[0076] Obviously, the above embodiments are merely examples for clarification and are not intended to limit the embodiments. Although the embodiments of the present application are described in conjunction with the figures, the person skilled in the art can make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations all fall within the scope of protection defined by the appended claims.

Claims

[1] Battery, characterized by that it includes the following: a housing (1) wherein a pole column assembly (31) is provided on the housing (1); a winding cell (2), wherein the winding cell (2) comprises a winding cell body (222) and comprising several pole vanes (221); and wherein the pole vanes (221) are designed for electrical connection with the pole column assembly (31) or with the housing (1); wherein in the unfolded state of the winding cell (2) along the longitudinal direction of the winding cell (2); the difference between the maximum thickness and the minimum thickness of the winding cell body (222) is d and the unit of d is mm, and where the number of winding layers of the winding cell body (222) is n, where the condition is satisfied: 0.08 ≤ d · n ≤ 0.9 and n ≤ 200. [2] Battery according to claim 1, characterized by, that the multiple pole vanes (221) are distributed in multiple layers along the radial direction of the winding cell body (222). [3] Battery according to claim 1 or 2, characterized by , that the width of a single polar vane (221) is E and the unit of E is mm, where the condition is satisfied: 2 mm ≤ E ≤ 9 mm. [4] Battery according to claim 1, characterized by , that several polar flags (221) are planned in the same location. [5] Battery according to claim 1, characterized by , that the difference d between the maximum thickness and the minimum thickness of the coiled cell body (222) satisfies the condition: 0.002mm ≤ d ≤ 0.012mm. [6] Battery according to claim 1, characterized by , that the dimension of the polar vane (221) along the radial direction is H and the unit of H is mm, where the condition is satisfied: 240 ≤ H / d ≤ 5000. [7] Battery according to claim 1, characterized by, that the pole flag (221) comprises a positive pole flag and a negative pole flag, and the positive pole flag and the negative pole flag are located on the same side of the winding cell body (222) along the axial direction; wherein one of the positive pole flag and the negative pole flag is electrically connected to the pole column assembly (31) and the other is electrically connected to the housing (1), wherein the condition is satisfied: 0.12 ≤ d · n ≤ 0.

8. [8] Battery according to claim 7, characterized by , that the diameter of the winding cell (2) is D and the unit of D is mm, where the condition is satisfied: 40 mm ≤ D ≤ 56 mm. [9] Battery according to claim 8, characterized by , that the dimension of the pole vane (221) along the radial direction H and the diameter of the winding cell (2) is D, where the condition is satisfied: 0.05 ≤ H / D ≤ 0.

25. [10] Battery according to claim 1, characterized by, that the polar vane (221) is rectangular and meets the condition: 0.002 mm ≤ d ≤ 0.008 mm; or the polar vane (221) is trapezoidal and meets the condition: 0.002 mm ≤ d ≤ 0.01 mm. [11] Battery according to any one of claims 1 to 10, characterized by , that several polar vanes (221) are stacked and form a polar vane area (21), wherein the polar vane area (21) is fan-shaped along the radial direction and satisfies the condition: 0.003 mm ≤ d ≤ 0.012 mm. [12] Battery according to any one of claims 1 to 10, characterized by, that the pole flag (221) comprises a positive pole flag and a negative pole flag, and the positive pole flag and the negative pole flag are each located on both sides of the winding cell body (222) along the axial direction; wherein the dimension of the pole flag (221) along the radial direction is H, the diameter of the winding cell (2) is D and the unit of D is mm, satisfying the condition: 0.03 ≤ H / D ≤ 0.

2. [13] Battery according to claim 12, characterized by , that the polar vane (221) is rectangular and meets the condition: 0.003 mm ≤ d ≤ 0.0085 mm; or the polar vane (221) is trapezoidal and meets the condition: 0.0035 mm ≤ d ≤ 0.011 mm. [14] Battery according to claim 13, characterized by , that along the radial direction the difference between the number of polar vanes (221) in the outermost position and the number of polar vanes (221) in the innermost position is m, where the condition is satisfied: m ≥ 3 and 0.002 mm ≤ d ≤ 0.01 mm. [15] Battery according to claim 14, characterized by , that m ≤ 8. [16] Battery according to any one of claims 1 to 10, characterized by , that along the radial direction the angle A enclosed between the connecting lines from the pole vane (221) in the outermost position or the pole vane (221) in the innermost position to the axis center of the winding cell (2) is, where the condition is satisfied: 0° < A ≤ 18°. [17] Battery according to any one of claims 1 to 10, characterized by , that the thickness of the coiled cell body (222) is C, where the condition is satisfied: C ≥ 0.080 mm; and also: 0.12 ≤ d · n ≤ 0.

8. [18] Battery according to any one of claims 1 to 10, characterized by , that the winding cell (2) includes a thinning region and the difference between the maximum thickness and the minimum thickness of the winding cell (2) in the thinning region is F, where the unit of F is µm and the condition is satisfied: 8µm ≤ F ≤ 60µm. [19] Battery according to any one of claims 1 to 10, characterized by , that the winding cell (2) is a cylindrical winding cell. [20] Battery according to claim 18, wherein the thinning area relates to an area in the coating of the pole plate (22) and the thickness of the thinning area is less than the thickness of other areas in the coating area. [21] Battery according to claim 20, characterized by that the thinning area is closer to the base of the polar flag. [22] Battery according to any one of claims 1 to 10, characterized by , that a cutting slot or gap is provided between adjacent polar flags of the multiple polar flags (221).

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