Battery

Abstract

A battery comprising: a housing and a cylindrical winding core (1), the housing comprising a terminal assembly, the cylindrical winding core (1) comprising a winding core hole (3) and an electrode layer (2); the electrode layer (2) comprising an electrode layer body and a plurality of electrode tabs; the electrode tabs being configured to establish electrical connection with at least one of the terminal assembly and the housing; the electrode layer (2) comprising a winding start end (6), and the electrode tabs comprising a first electrode tab (7); along a longitudinal direction, when the electrode layer (2) is spread out, a distance between the first electrode tab (7) and the winding start end (6) is D1, an area of ​​the winding core hole (3) is S, and D1 / S is in a range of 3 to 45.

Description

Technical area

[0001] This application relates to the field of accumulator technology or battery technology. Specifically, this application relates to a battery or accumulator. background

[0002] A battery is formed by winding positive electrode layers, negative electrode layers, and separators into a winding core according to a predetermined number of layers and turns. After winding, a winding core hole is formed. Furthermore, after winding, the first electrode tab may cover the winding core hole, which is detrimental to subsequent wetting of the electrode layers by electrolyte in the winding core hole. Summary

[0003] Against this background, the present application provides a battery that solves the problem of electrode tabs covering the winding core hole, which impairs electrolyte injection and electrolyte wetting of electrode layers in the battery.

[0004] According to a first aspect, the present application provides a battery. The battery comprises a housing and a cylindrical winding core. The housing includes a terminal assembly. The cylindrical winding core includes a winding core hole and an electrode layer. The electrode layer includes an electrode layer body and a plurality of electrode tabs; the electrode tabs are configured to establish an electrical connection with the terminal assembly and / or the housing; wherein the electrode layer comprises a winding start end, and the electrode tabs comprise a first electrode tab. Along a longitudinal direction, when the electrode layer is unfolded, a distance between the first electrode tab and the winding start end is D1. An area of ​​the winding core hole is S, and D1 / S is in a range of 3 to 45.

[0005] Advantageous Effects: The embodiment of the present application limits the distance between the first electrode tab and the coil starting end while limiting the area of ​​the coil core hole, thereby allowing comprehensive adjustment of the pitch and area of ​​the coil core hole. When the area of ​​the coil core hole is larger, the pitch also needs to be larger, thereby preventing the coil core hole position from being covered after the electrode tabs are folded, which would impair fluid injection.When the injection hole and the electrode tabs are located on the same side, the electrode tabs prevent the electrode tabs from directly affecting the injection of electrolyte into the winding core hole; when the injection hole and the electrode tabs are located at different ends, the electrode tabs prevent the winding core hole from covering, which would otherwise affect the wetting of electrolyte in the winding core hole up to the electrode core. In addition, the ratio between the distance and the area cannot be too small. If it is too small, the distance between the first electrode tab and the winding start end is too small, while the area of ​​the winding core hole is too large, so the electrode tabs quickly cover the winding core hole after folding, affecting liquid injection.If it is too large, the distance between the electrode tabs and the winding start end is too large. Since the electrode tabs mainly carry overcurrent, this means that a part of the electrode layer has no electrode tabs, resulting in poor overcurrent capability in that part. Therefore, limiting the distance between the first electrode tab and the winding start end within this value range can ensure the overcurrent capability of the electrode tab. In addition, the size of the winding core hole must also be controlled, and the area of ​​the winding core hole must also be within a certain range. If it is too small, it is unfavorable for electrolyte injection and gas discharge. Brief description of the drawings

[0006] To better illustrate the technical solutions in the specific embodiments or corresponding technologies of the present application, a brief introduction to the drawings is provided, which are to be used in the description of the specific embodiments or related technologies. It is understood that the drawings described below show some embodiments of the present application. Those skilled in the art can obtain other drawings based on these drawings without creative effort. Fig. 1 is a schematic diagram of the overall structure of the winding core in an embodiment of the present application; Fig. 2 is a plan view of the winding core in one embodiment of the present application; Fig. 3 is a cross-sectional view of the battery in one embodiment of the present application; Fig. 4 is a schematic diagram of the injection hole and the electrode tab arranged on the same side in one embodiment of the present application; Fig. 5 is a schematic representation of the injection hole and the electrode tab arranged on different sides in an embodiment of the present application; Fig. 6 is a schematic representation of the electrode layer in the spread state in an embodiment of the present application; Fig. 7 is a schematic diagram in which D3 is marked on the spread electrode layer in one embodiment of the present application. Reference numbers:

[0007] 1. cylindrical winding core; 2. electrode layer; 3. winding core hole; 4. positive electrode layer; 5. negative electrode layer; 6. winding start end; 7. first electrode tab; 8. second electrode tab; 9. winding end; 10. third electrode tab; 11. fourth electrode tab; 12. injection hole. Detailed description

[0008] To clarify the purposes, technical solutions, and advantages of the present application, the technical solutions in the embodiments of the present application are clearly and completely described below in conjunction with the accompanying drawings. The described embodiments are, of course, only some of the embodiments of the present application, but not all. All other embodiments that a person skilled in the art creates without creative effort based on the embodiments of the present application fall within the scope of the present application.

[0009] In the description of the present application, it should be noted that terms such as "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate orientations or positional relationships, are based on the orientations or positional relationships shown in the drawings, are used only to describe the present application and simplify the description, and do not indicate or imply that the mentioned devices or elements have particular orientations or must be constructed or operated in particular orientations. Therefore, they should not be understood as limitations of the present application. Furthermore, terms such as "first," "second," and "third" are used solely for descriptive purposes and should not be understood to indicate or imply relative priority.

[0010] In describing the present disclosure, it should be noted that the terms "installed," "connected," and "coupled" are to be understood broadly unless expressly stated and limited otherwise. For example, they may refer to permanent connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections via intermediate elements or internal communication between two elements; wireless connection or wired connection. A person skilled in the art will understand the specific meanings of the above terms in the present application according to the specific circumstances.

[0011] Moreover, the technical features incorporated in the various embodiments of the present application may be combined with each other as long as they do not conflict with each other.

[0012] A battery is formed by winding positive electrode layers 4, negative electrode layers 5, and separators according to a predetermined number of layers and turns into a cylindrical winding core 1. The battery comprises a cylindrical winding core 1 and a casing. The casing may be circular, but may also have a different shape, such as a hexagonal prism. The casing material may be made of steel, aluminum, etc. In particular, it may be made of stainless steel, nickel-plated steel, aluminum alloy, aluminum-manganese alloy, etc. Of course, other materials may also be used. The above are merely illustrative and should not be understood as limiting, provided the same technical effect can be achieved.

[0013] The cylindrical winding core 1 includes an electrode layer 2, and after the electrode layer 2 is wound, a winding core hole 3 is formed. Along the longitudinal direction, when the electrode layer 2 is spread out, the first electrode tab 7 is normally located at a certain distance from the winding start end 6 of the electrode layer 2. The winding start end 6 is the starting end of the winding. If the first electrode tab 7 is placed directly at the winding start end 6, the first electrode tab 7 can cover the winding core hole 3 after winding is completed. Therefore, in this embodiment, the distance between the first electrode tab 7 and the winding start end 6 is controlled within a certain range to prevent the first electrode tab 7 from covering the winding core hole 3 after winding.Since the electrode tabs primarily absorb the overcurrent, too large a distance between the first electrode tab 7 and the winding start end 6 results in poor overcurrent capability, which significantly affects battery performance. If the distance between the first electrode tab 7 and the winding start end 6 is too small, it still obscures the winding core hole 3.

[0014] By comprehensively controlling the distance between the first electrode tab 7 and the winding start end 6 as well as the area of ​​the winding core hole 3, the present application can prevent the first electrode tab 7 from covering the winding core hole 3 and impairing the wetting of the electrode core by the electrolyte, while at the same time ensuring the overcurrent capability of the electrode layer 2.

[0015] There is a distance D1 between the first electrode tab 7 and the winding start end 6, as shown in the Fig. 6 and Fig. 7, where D1 denotes the minimum distance between the first electrode tab 7 and the winding start end 6. Furthermore, the electrode tabs can be rectangular or trapezoidal.

[0016] Of course, this embodiment represents only examples of specific shapes of electrode tabs and is not intended to be limiting. Those skilled in the art may make modifications depending on the actual circumstances, as long as the same technical effect can be achieved.

[0017] The area of ​​the winding core hole 3 is S, and the ratio between the distance and the area is D1 / S. If D1 / S is too large, that is, either D1 is too large or S is too small, it will result in poor overcurrent capability of the electrode layer 2. In addition, if S is too small, the capacity of the winding core hole 3 to store electrolyte will be affected, which is unfavorable for the subsequent wetting of the electrode layer 2 by the electrolyte in the winding core hole 3; the ratio cannot be too small, if D1 is too small or S is too large, the electrode tabs can easily cover the winding core hole 3. And if the area of ​​the winding core hole 3 is relatively large, the risk of electrode tabs covering the winding core hole 3 increases, which affects the electrolyte wetting of the electrode core.

[0018] In the present application, the housing further includes an injection hole 12, and the positive electrode tabs, the negative electrode tabs, and the injection hole 12 can be located on the same side or on different sides. When the positive electrode tabs, the negative electrode tabs, and the injection hole 12 are located on the same side, there is a greater risk that the positive electrode tabs and the negative electrode tabs will cover the winding core hole 3, so D1 must be larger or S smaller. However, S must not be too small, otherwise the amount of electrolyte that the winding core hole 3 can store will be compromised, which is unfavorable for the subsequent wetting of the electrode layer 2 by the electrolyte in the winding core hole 3.If the injection hole 12 and the electrode tabs are arranged on different sides, the electrode tabs covering the winding core hole 3 impair the wetting of the electrode core by the electrolyte in the winding core hole 3.

[0019] The embodiments of the present application are described below in connection with Fig. 1 to 7 are described in more detail.

[0020] According to an embodiment of the present application, a battery is provided according to one aspect. As shown in Fig. As shown in Figure 1, the cylindrical winding core 1 comprises a winding core hole 3 and an electrode layer 2. The electrode layer 2 comprises an electrode layer body and a plurality of electrode tabs. The electrode tabs are configured to establish an electrical connection with the terminal assembly and the housing. Alternatively, the electrode tabs can also be electrically connected only to the terminal assembly or only to the housing.

[0021] In this embodiment of the present application, the electrode layer 2 further comprises a winding start end 6. The electrode tabs comprise a first electrode tab 7. Along the longitudinal direction, when the electrode layer 2 is spread out, the distance between the first electrode tab 7 and the winding start end 6 is D1. The area of ​​the winding core hole 3 is S, and D1 / S is in a range of 3 to 45. Specifically, the value of D1 / S may be one of 3, 10, 15, 20, 25, 30, 35, or 40, or any value between any two of these values.

[0022] As in Fig. As shown in Figure 2, the winding start end 6 of the electrode layer 2 is located at the end closest to the winding core hole 3. This means that the electrode layer 2 begins winding at the winding start end 6, i.e., at the beginning of the winding. Furthermore, since a plurality of electrode tabs are arranged on the electrode layer 2, the electrode tab closest to the winding start end 6 is defined as the first electrode tab 7.

[0023] Regarding the method for manufacturing electrode tabs, in this embodiment, the electrode layer 2 comprises a current collector and an active material layer, with the active material layer being applied to the current collector. The electrode tabs can be manufactured by cutting the current collector. Alternatively, the electrode tabs can also be separate conductive elements electrically connected to the current collector. The current collector can be made of aluminum or copper.

[0024] With such an arrangement, the embodiment of the present application limits the distance between the first electrode tab 7 and the coil starting end 6 while simultaneously limiting the area of ​​the coil core hole 3. This allows for comprehensive adjustment of the distance and area of ​​the coil core hole 3. When the area of ​​the coil core hole 3 is larger, the distance must also be larger to prevent the position of the coil core hole 3 from being obscured after the electrode tabs are folded, which would otherwise impede liquid injection. When the injection hole 12 and the electrode tabs are on the same side, the electrode tabs directly block the injection of electrolyte into the coil core hole 3.If the injection hole 12 and the electrode tabs are arranged at different ends, the electrode tabs covering the winding core hole 3 will impair the wetting of electrolyte in the winding core hole 3 to the electrode core. When arranged on different sides, the electrolyte must be injected into the winding core hole 3 from the injection hole end, and the electrode tabs covering the winding core hole 3 prevent the electrolyte in the winding core hole 3 from flowing out to wet the electrode core. In addition, the ratio between the distance and the area must not be too small. If it is too small, the distance between the first electrode tab 7 and the winding start end 6 will be too small, and the area of ​​the winding core hole 3 will be too large. In this case, the first electrode tab is likely to cover the winding core hole 3 after folding, thereby impairing liquid injection.If it is too large, the distance between the electrode tabs and the winding start end 6 is too large. Since the electrode tabs primarily carry overcurrent, this means that a portion of the electrode layer 2 lacks electrode tabs, resulting in poor overcurrent capability in that portion. Therefore, by limiting the distance between the first electrode tab 7 and the winding start end 6 within this range, the overcurrent capability of the electrode layer 2 can be ensured.

[0025] In addition, the size of the winding core hole 3 must also be controlled, and the area of ​​the winding core hole 3 must also be within a certain range. If the area is too small, it is unfavorable for electrolyte injection and gas discharge. In particular, when the injection hole 12 and the electrode tabs are on the same side, the electrode tabs may cover the injection hole 12, thereby impairing direct liquid injection. If the injection hole 12 and the electrode tabs are on different sides, the electrode tabs will cover the winding core hole 3. In practice, it may happen that the electrode tabs are located on the top of the battery while the injection hole 12 is located at the bottom. Theoretically, during injection, the problem of the electrode tab covering the injection hole can be avoided if the side with the injection hole 12 is placed facing up.In practice, however, due to gravity or other factors, the electrode tabs may sag and cover the injection hole 12, resulting in poor electrolyte flow. If the electrolyte cannot flow evenly from the winding core hole 3 to wet the end face of the electrode core, this not only affects the uniform wetting of the internal battery materials, but can also cause safety risks and reduce battery performance and service life. The area of ​​the winding core hole 3 can be in the range of 0.7 mm. 2 up to 80 mm 2 in particular it can be 0.7 mm 2 , 25 mm 2 , 10 mm 2 , 20 mm 2 , 30 mm 2 , 40 mm 2 , 50 mm 2 , 60 mm 2 , 70 mm 2 , 80 mm 2 or any value between any two of these values.

[0026] In addition, in an optional embodiment, as in Fig. As shown in Figure 6, when the electrode layer 2 is spread out or unfolded in the plane in which the electrode layer 2 is located, a direction perpendicular to the winding direction of the electrode layer 2 is defined as the height direction of the electrode tabs. The height of the first electrode tab 7 is H, and the ratio between the distance and the height is D1 / H, where D1 / H is in a range from 18 to 240. Specifically, the value of D1 / H can be any of 18, 40, 80, 120, 160, 200, or 240, or any value between any two of these values. In this embodiment of the present application, H is in a range of 2.5 mm to 15 mm.

[0027] Since, with such an arrangement, the higher the height of the electrode tabs, the more likely they are to cover the winding core hole 3 after folding, it is necessary to set a larger distance between the first electrode tab 7 and the winding start end 6 as the height of the electrode tabs increases to reduce the area that covers the winding core hole 3 after folding. Furthermore, the height of the first electrode tab 7 cannot be too small, otherwise the total overcurrent area of ​​the first electrode tab 7 will be compromised, thereby reducing its overall overcurrent capability.

[0028] In an optional embodiment, as in Fig. 1, the electrode layer 2 further comprises a positive electrode layer 4 and a negative electrode layer 5.

[0029] Specifically, in this embodiment of the present application, the positive electrode layer 4 is provided with a plurality of positive electrode tabs on one side of the winding core hole 3 along the axial direction of the winding core hole 3. The plurality of positive electrode tabs may be arranged at intervals. The specific interval values ​​can be adjusted by a person skilled in the art depending on the actual circumstances. This embodiment does not impose any limitations as long as the same technical effect can be achieved.

[0030] Similarly, the negative electrode layer 5 is provided with a plurality of negative electrode tabs along the axial direction of the winding core hole 3 on the other side of the winding core hole 3. The plurality of negative electrode tabs may also be arranged at intervals. The specific interval values ​​can be adjusted by a person skilled in the art depending on the actual circumstances. This embodiment does not impose any limitations as long as the same technical effect can be achieved.

[0031] Of course, in this embodiment, the positive and negative electrode tabs can be arranged on the same side of the winding core hole 3 or on opposite sides along the axial direction of the winding core hole 3. In concrete implementations, a person skilled in the art may make changes depending on the actual circumstances. This embodiment is for illustrative purposes only and is not intended to impose any limitations as long as the same technical effect can be achieved.

[0032] Moreover, in this embodiment of the present application, examples are given of both arrangement methods of the above positive electrode tabs and negative electrode tabs.

[0033] As in Fig. As shown in Figure 2, when the electrode layer 2 is spread out, D1 is in a range between 200 mm and 900 mm when the positive and negative electrode tabs are arranged on the same side of the winding core hole 3. Specifically, it may be any of 200 mm, 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, or 900 mm, or any value between any two of these values.

[0034] In other words, when the positive electrode tabs and the negative electrode tabs are arranged on the same side of the winding core hole 3, the distance between the positive electrode tabs and the winding start end 6 of the positive electrode layer 4 may be in a range between 200 mm and 900 mm, and the distance between the negative electrode tabs and the winding start end 6 of the negative electrode layer 5 may be in a range between 200 mm and 900 mm.

[0035] Furthermore, the distance between the positive electrode tabs and the winding start end 6 of the positive electrode layer 4 and the distance between the negative electrode tabs and the winding start end 6 of the negative electrode layer 5 can be the same or different. If the distances between the positive electrode tabs and the negative electrode tabs to the winding start end 6 are different, the smaller distance between the positive electrode tabs and the negative electrode tabs to the winding start end 6 is assumed to be D1.

[0036] A specialist can make changes depending on the actual circumstances.

[0037] When the positive electrode tabs and negative electrode tabs are arranged on opposite sides along the axial direction of the winding core hole 3 (not shown in the figures), D1 is in a range of 150 mm to 850 mm when the electrode layer 2 is spread out. Specifically, it may be any of 200 mm, 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, or 850 mm, or any value between any two of these values.

[0038] In other words, when the positive electrode tabs and negative electrode tabs are located on opposite sides, the distance between the positive electrode tabs and the winding start end 6 of the positive electrode layer 4 may be in a range between 150 mm and 850 mm, and the distance between the negative electrode tabs and the winding start end 6 of the negative electrode layer 5 may be in a range between 150 mm and 850 mm.

[0039] Likewise, the distance between the positive electrode tabs and the winding start end 6 of the positive electrode layer 4 and the distance between the negative electrode tabs and the winding start end 6 of the negative electrode layer 5 can be the same or different. A person skilled in the art can make changes depending on the actual circumstances. If the distances between the positive electrode tabs and the negative electrode tabs to the winding start end 6 are different, the smaller distance between the positive electrode tabs and the negative electrode tabs to the winding start end 6 is assumed to be D1.

[0040] It should be noted that when the positive and negative electrode tabs are arranged on the same side of the winding core hole 3, the probability that the positive and negative electrode tabs will cover the injection hole 12 increases. Therefore, the distance between the first electrode tab 7 and the winding start end 6 of the electrode layer 2 can be set larger compared to the arrangement on opposite sides to prevent the first electrode tab 7 from covering the winding core hole 3.

[0041] Moreover, when the positive electrode tabs and negative electrode tabs are arranged on the same side of the winding core hole 3, if the first electrode tab 7 is too close to the initial end of the electrode layer 2, there will be insufficient insulation distance between the electrode tabs after winding, which may lead to unintentional contact and short circuit, which in turn may result in rapid heat buildup, battery damage, or even safety problems.

[0042] By further restricting the distance between the first electrode tab 7 and the winding start end 6, a sufficient safety distance between positive and negative electrode tabs can be ensured even under extreme conditions, such as vibrations or deformations.

[0043] In an optional embodiment, as in Fig. 6, H is in a range of 2.5 mm to 12 mm when the positive and negative electrode tabs are arranged on the same side of the winding core hole 3. Specifically, it may be any of 2.5 mm, 4 mm, 6 mm, 8 mm, 10 mm, or 12 mm, or any two between these values; that is, when the first electrode tab 7 is a positive electrode tab, the height of the positive electrode tab is in a range of 2.5 mm to 12 mm; when the first electrode tab 7 is a negative electrode tab, the height of the negative electrode tab is in a range of 2.5 mm to 12 mm.

[0044] Likewise, the heights of the positive electrode tab and the negative electrode tab can be the same or different. A specialist can make adjustments depending on the actual circumstances. If the heights of the positive electrode tab and the negative electrode tab are different, the larger value between the two is taken as H.

[0045] When the positive electrode tabs and negative electrode tabs are arranged on opposite sides along the axial direction of the winding core hole 3 (not shown in the figures), H is in a range of 3.5 mm to 15 mm. Specifically, it may be any of 3.5 mm, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, or 13 mm, or any two between these values. That is, the height of the positive electrode tabs is in a range of 3.5 mm to 13 mm, and the height of the negative electrode tabs is in a range of 3.5 mm to 13 mm.

[0046] Likewise, the heights of the positive and negative electrode tabs can be the same or different. A specialist can make adjustments depending on the actual circumstances. If the heights of the positive and negative electrode tabs are different, the larger value between the two is taken as H.

[0047] With such an arrangement, by controlling the heights of the positive electrode tabs and negative electrode tabs within a certain range, the winding core hole 3 can be prevented from being covered due to the excessive size of the positive electrode tabs and negative electrode tabs.

[0048] Furthermore, in an optional embodiment, the positive electrode tabs comprise a first positive electrode tab, wherein the first positive electrode tab is closest to the winding start end 6 of the positive electrode layer. A first distance exists between the first positive electrode tab and the winding start end of the positive electrode layer.

[0049] Similarly, the negative electrode tabs comprise a first negative electrode tab, wherein the first negative electrode tab is closest to the winding start end 6 of the negative electrode layer 5. A second distance exists between the first negative electrode tab and the winding start end 6 of the negative electrode layer 5.

[0050] Furthermore, the absolute value of the difference between the first and second distances is in a range from 0 mm to 50 mm. That is, when the first distance is greater than the second distance, the difference between the first distance and the second distance is in a range from 0 mm to 50 mm; when the second distance is greater than the first distance, the difference between the second distance and the first distance is in a range from 0 mm to 50 mm. In particular, it can be any of 0 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm or 50 mm, or any value between any two of these values.

[0051] Since such an arrangement achieves symmetry and manufacturing consistency for the first positive and first negative electrode tabs, it contributes to simplifying the production process and improving production efficiency. Furthermore, sufficient insulation protection between the positive and negative electrode tabs must be ensured during the actual manufacturing process, and measures must be taken during the winding and packaging phases to avoid potential short-circuit risks.

[0052] In an optional embodiment, as in Fig. 6, the electrode layer 2 further comprises a winding end 9, and the electrode tab closest to the winding end 9 is a second electrode tab 8. The winding end 9 is the end of the electrode layer 2 after completion of winding.

[0053] Along the longitudinal direction, when the electrode layer 2 is spread out, there is a distance D2 between the second electrode tab 8 and the winding end 9, and D2 lies in a range of 50 mm to 600 mm. In particular, it can be any of 50 mm, 100 mm, 200 mm, 300 mm, 400 mm, 500 mm, or 600 mm, or any value between any two of these values.

[0054] Similarly, D2 refers to the Fig. 6 and Fig. 7, to the minimum distance between the second electrode tab 8 and the winding end 9. In addition, the electrode tabs can be rectangular or trapezoidal.

[0055] Of course, this embodiment only represents examples of specific shapes of electrode tabs and is not intended to be limiting. A person skilled in the art may make modifications depending on the actual circumstances, as long as the same technical effect can be achieved.

[0056] Since in this embodiment of the present application there is a certain distance between the second electrode tab 8 and the winding end 9, it is possible to avoid the insulation between the electrode tabs and the housing being impaired due to an excessively small distance, and it is also avoided that the overcurrent capacity of the electrode layer 2 is impaired due to an excessively large distance.

[0057] Furthermore, in an optional embodiment, the cylindrical winding core 1 comprises a plurality of winding layers arranged along the radial direction, and some winding layers are not provided with electrode tabs.

[0058] In this embodiment of the present application, it is not necessary to provide electrode tabs for all winding layers. As in Fig. As shown in Figure 1, only some winding layers may be provided with electrode tabs, while other winding layers may not have electrode tabs. Furthermore, the winding layers with and without electrode tabs may be arranged alternately, so that the electrode tabs are distributed discontinuously.

[0059] Since some winding layers are not provided with electrode tabs in this embodiment, after cutting the electrode tabs, the area connected to the electrode layer body is first machined, and then the electrode tabs are flattened and folded. Therefore, if all winding layers are provided with electrode tabs, folding would be difficult due to the excessive thickness of the electrode tabs.

[0060] In an optional embodiment, a winding layer without electrode tabs is also present. In a first winding layer and a second winding layer, which are adjacent to the winding layer without electrode tabs and are both provided with electrode tabs, a third electrode tab 10 is arranged on the first winding layer and a fourth electrode tab 11 is arranged on the second winding layer. The third electrode tab 10 is closer to the winding core hole 3 than the fourth electrode tab 11. In particular, the third electrode tab 10 is located at a position away from the starting end of the electrode layer 2 in the first winding layer, while the fourth electrode tab 11 is located at a position near the starting end of the electrode layer 2 in the second winding layer.

[0061] That is, a winding layer without electrode tabs is located between the first winding layer and the second winding layer. Specifically, in this embodiment, one or a plurality of consecutive winding layers without electrode tabs are present in the cylindrical winding core 1, and electrode tabs are arranged on two winding layers adjacent to these layers, and there is a gap between adjacent electrode tabs on these two winding layers.

[0062] The distance between the third electrode tab 10 and the fourth electrode tab 11 is L1, where L1 is in a range from 20 mm to 280 mm. In particular, it can be any of 20 mm, 40 mm, 80 mm, 120 mm, 160 mm, 200 mm, 240 mm, or 280 mm, or any value between any two of these values.

[0063] This embodiment facilitates the folding of electrode tabs in the radial direction of the winding core hole 3 by providing one or a plurality of consecutive winding layers without electrode tabs in the cylindrical winding core 1, thereby avoiding difficulties in folding electrode tabs. Furthermore, by setting a distance between adjacent electrode tabs, it is avoided that there are too many layers without electrode tabs, which would lead to insufficient overcurrent capacity in the winding layers without electrode tabs.

[0064] Setting a specific distance between electrode tabs on adjacent winding layers helps control the current distribution to a certain extent and improves the stability and safety of the battery structure. Too small a distance would increase the number of electrode tabs for a fixed winding length of electrode layer 2 and make it difficult to fold the electrode tabs. Too large a distance would reduce the number of electrode tabs for a fixed winding length of electrode layer 2. Once the number of electrode tabs is reduced to a certain level, it would seriously affect the overall overcurrent performance of the battery. In addition, appropriate spacing between electrode tabs contributes to thermal management, preventing local overheating and reducing the risk of thermal runaway.In addition, an appropriate distance between electrode tabs prevents interference during welding or joining, which improves production efficiency and quality.

[0065] In an optional embodiment, the cylindrical winding core 1 further comprises a plurality of winding layers. In some winding layers, the electrode tabs are not welded to the terminal assembly or the housing. The number of winding layers not welded to the terminal assembly or the housing is less than or equal to 15 and greater than or equal to 2.

[0066] In this embodiment of the present application, by limiting the number of winding layers whose electrode tabs are not welded, the stability of the battery's internal structure and the reliability of the electrical connections can be ensured, and the overcurrent performance of the electrode tabs can be prevented from being compromised by too many unwelded layers. Furthermore, this can prevent excessively dangling conductors from moving inside the battery, reduce the risk of short circuits, and ensure good electrical contact even when the battery is subject to vibration or deformation.

[0067] Furthermore, in an optional embodiment, the housing also includes an injection hole 12, and the positive electrode tabs, the negative electrode tabs, and the injection hole 12 are all located on the same side. D1 / S ranges from 4 to 38. In particular, it can be any of 4, 10, 15, 20, 25, 30, 35, or 38, or any value between any two of these values.

[0068] In such an arrangement, if the electrode tabs and the injection hole 12 are located at the same end, there is a greater risk that the electrode tabs will cover the winding core hole 3. Therefore, D1 must be larger or S smaller. However, S cannot be too small, as this would impair electrolyte storage. Therefore, D1 and S can be widely adjusted to achieve the same technical effect. This embodiment is not intended to provide any limitation, and a person skilled in the art may make modifications depending on the actual circumstances.

[0069] Furthermore, in an optional embodiment, the ratio between the area of ​​the injection hole 12 and the area of ​​the winding core hole 3 may be in a range of 0.2 to 0.8. Specifically, it may be any of 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8, or any value between any two of these values.

[0070] In such an arrangement, if the electrode tabs and the injection hole 12 are arranged at the same end, the electrode tabs tend to cover the injection hole 12, which impairs liquid injection. The ratio between the area of ​​the injection hole 12 and the area of ​​the winding core hole 3 must not be too small. If the ratio is too small, the area of ​​the winding core hole 3 would become relatively large, increasing the risk of electrode tabs covering the winding core hole 3. And / or the area of ​​the injection hole 12 would be too small, resulting in low injection efficiency. Combined with the high risk of the winding core hole 3 being covered, the wetting effect of the electrolyte on the electrode layer 2 would be poor. However, the ratio between the areas must not be too large either.If the area of ​​the injection hole 12 is too large while the area of ​​the winding core hole 3 is too small, this would reduce the amount of electrolyte that can be accommodated in the winding core hole 3.

[0071] Since the cylindrical winding core 1 comprises a plurality of winding layers, in an optional embodiment, the winding layer closest to the winding core hole 3 is defined as the first winding layer.

[0072] As in Fig. As shown in Figure 7, the distance D3 between the first winding layer and the adjacent winding layer is between 20 mm and 80 mm when the electrode layer 2 is spread out. In particular, it may be any of 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, or 80 mm, or any value between any two of these values.

[0073] Each winding layer typically has a specific number of electrode tabs. If the first winding layer comprises only a single electrode tab, namely the first electrode tab 7, D3 is the distance between the first electrode tab 7 and an electrode tab in the adjacent winding layer.

[0074] Similarly, D3 refers to the Fig. 6 and Fig. 7, refers to the minimum distance between the first electrode tab 7 and an electrode tab in the adjacent winding layer. Furthermore, the electrode tabs can be rectangular or trapezoidal.

[0075] Of course, this embodiment only represents examples of specific shapes of electrode tabs and is not intended to be limiting. A person skilled in the art may make modifications depending on the actual circumstances, as long as the same technical effect can be achieved.

[0076] When the first winding layer comprises a plurality of electrode tabs, D3 refers to the distance between adjacent electrode tabs in the first winding layer and the adjacent winding layer.

[0077] In such an arrangement, to prevent the electrode tabs from covering the winding core hole 3, an increase in the distance between the first electrode tab 7 and the winding start end 6 would lead to a deterioration of the overcurrent capacity of the electrode layer 2. Therefore, it is necessary to control the distance between the first electrode tab 7 and adjacent electrode tabs to avoid excessive deterioration of the overcurrent capacity.

[0078] Although the embodiments of the present application have been described in conjunction with the drawings, various modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the present application. Such modifications and variations are within the scope of the appended claims.

Claims

[1] A battery comprising: a housing and a cylindrical winding core (1), the housing comprising a terminal assembly, the cylindrical winding core (1) comprising a winding core hole (3) and an electrode layer (2); the electrode layer (2) comprising an electrode layer body and a plurality of electrode tabs; the electrode tabs being configured to make electrical connection with at least one of the terminal assembly and the housing; the electrode layer (2) comprising a winding start end (6), and the electrode tabs comprising a first electrode tab (7); along a longitudinal direction, when the electrode layer (2) is spread out, a distance between the first electrode tab (7) and the winding start end (6) is D1, an area of ​​the winding core hole (3) is S, and D1 / S is in a range of 3 to 45. [2] The battery according to claim 1, wherein, when the electrode layer (2) is spread out, in a plane in which the electrode layer (2) is arranged, a direction perpendicular to a winding direction of the electrode layer (2) is defined as a height direction of the electrode tabs, a height of the first electrode tab (7) is H, a ratio between the distance between the first electrode tab (7) and the winding start end (6) and the height is D1 / H, and D1 / H is in a range of 18 to 240. [3] Battery according to claim 2, wherein the electrode layer (2) further comprises: a positive electrode layer (4), and along an axial direction of the winding core hole (3), the positive electrode layer (4) is provided with a plurality of positive electrode tabs on one side of the winding core hole (3); a negative electrode layer (5), and along the axial direction of the winding core hole (3), the negative electrode layer (5) is provided with a plurality of negative electrode tabs on one side of the winding core hole (3). [4] Battery according to claim 3, wherein the positive electrode tabs and the negative electrode tabs are arranged on the same side along the axial direction of the winding core hole (3), and when the electrode layer (2) is spread out, D1 is in a range of 200 mm to 900 mm; or the positive electrode tabs and the negative electrode tabs are arranged on opposite sides along the axial direction of the winding core hole (3), and when the electrode layer (2) is spread out, D1 is in a range of 150 mm to 850 mm. [5] Battery according to claim 3 or 4, wherein, when the positive electrode tabs and the negative electrode tabs are arranged on the same side of the winding core hole (3), H is in a range of 2.5 mm to 12 mm; or, when the positive electrode tabs and the negative electrode tabs are arranged on opposite sides along the axial direction of the winding core hole (3), H is in a range of 3.5 mm to 15 mm. [6] Battery according to one of claims 3 to 5, wherein the positive electrode tabs comprise a first positive electrode tab, wherein the first positive electrode tab is closest to the winding start end (6) of the positive electrode layer (4); a first distance exists between the first positive electrode tab and the winding start end (6) of the positive electrode layer (4); wherein the negative electrode tabs comprise a first negative electrode tab, wherein the first negative electrode tab is closest to the winding start end (6) of the negative electrode layer (5); a second distance exists between the first negative electrode tab and the winding start end (6) of the negative electrode layer (5); an absolute value of a difference between the first distance and the second distance is in a range from 0 mm to 50 mm. [7] A battery according to any one of the preceding claims, wherein the electrode layer (2) further comprises a winding end (9) and an electrode tab closest to the winding end (9) is a second electrode tab (8); along the longitudinal direction, when the electrode layer (2) is spread out, there is a distance D2 between the second electrode tab (8) and the winding end (9), and D2 is in a range of 50 mm to 600 mm. [8] A battery according to any one of the preceding claims, wherein the cylindrical winding core (1) comprises a plurality of winding layers arranged along a radial direction and some of the winding layers are not provided with electrode tabs. [9] A battery according to claim 8, wherein there is a winding layer without electrode tabs, and in a first winding layer and a second winding layer adjacent to the winding layer without electrode tabs and both provided with electrode tabs, a third electrode tab (10) is arranged on the first winding layer, a fourth electrode tab (11) is arranged on the second winding layer, the third electrode tab (10) is arranged closer to the winding core hole (3) compared to the fourth electrode tab (11), the third electrode tab (10) being located at a position away from a starting end of the electrode layer (2) in the first winding layer; and the fourth electrode tab (11) being located at a position near the starting end of the electrode layer (2) in the second winding layer;wherein a distance between the third electrode tab (10) and the fourth electrode tab (11) is L1 and L1 is in a range of 20 mm to 280 mm; [10] Battery according to one of the preceding claims, wherein the cylindrical winding core (1) comprises a plurality of winding layers and electrode tabs in some winding layers are not welded to the terminal arrangement or the housing, wherein a number of winding layers not welded to the terminal arrangement or the housing is less than or equal to 15 and greater than or equal to 2. [11] A battery according to any one of claims 4 to 10, wherein the casing further comprises an injection hole (12), and the positive electrode tabs, the negative electrode tabs, and the injection hole (12) are all arranged on the same side; and wherein D1 / S is in a range of 4 to 38. [12] The battery according to claim 11, wherein a ratio between an area of ​​the injection hole (12) and the area of ​​the winding core hole (3) is in a range of 0.2 to 0.

8. [13] Battery according to one of the preceding claims, wherein, when the electrode layer (2) is spread out, a distance D3 between adjacent electrode tabs between a first winding layer and an adjacent winding layer is in a range of 20 mm to 80 mm; the first winding layer is the winding layer closest to the winding core hole (3); when the first winding layer comprises only the first electrode tab (7), D3 is a distance between the first electrode tab (7) and an electrode tab in the adjacent winding layer; when the first winding layer comprises a plurality of electrode tabs, D3 is a distance between adjacent electrode tabs in the first winding layer and the adjacent winding layer. [14] Battery according to one of the preceding claims, wherein the housing material is made of steel or aluminum, and / or wherein the housing material is made of stainless steel, nickel-plated steel, aluminum alloy or aluminum-manganese alloy. [15] A battery according to any one of the preceding claims, wherein the electrode layer comprises a current collector and an active material layer, the active material layer being applied to the current collector. [16] The battery of claim 15, wherein the electrode tabs are made by cutting the current collector or the electrode tabs are separate conductive elements electrically connected to the current collector. [17] A battery according to claim 15 or 16, wherein the current collector is made of aluminum or copper.

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