Battery

Abstract

The battery provided by the invention comprises a battery cell and a shell, wherein the battery cell comprises a first pole piece and a second pole piece; the first pole piece comprises a first current collector and a first tab extending from one side of the first current collector, and the second pole piece comprises a second current collector and a second tab extending from one side of the second current collector; the first tab and the second tab are both located on one side of the battery cell in the first direction, and the first tab and the second tab are arranged at an interval in the second direction; the battery cell is accommodated in the shell, the shell comprises a first shell wall, a transition wall, and a second shell wall and a third shell wall which are oppositely arranged along a second direction, and the first shell wall and the second shell wall are connected through the transition wall; the first tab is arranged close to the second shell wall relative to the second tab; and the maximum distance D1 between the first tab and the second shell wall and the curvature radius R1 of the transition wall satisfy 1.5 < = D1 / R1 < = 3. The battery disclosed by the invention is relatively high in safety.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery. Background Technology

[0002] Due to ergonomic design and appearance requirements, the battery compartment space of smart wearable devices (such as smartwatches, health monitoring bracelets, AR / VR devices, etc.) is often limited, and they are often curved, requiring batteries with corresponding curvature to power them.

[0003] In related technologies, a battery includes a cell and a casing. Both the cell and the casing are arc-shaped. One side of the cell has a positive tab and a negative tab. The negative tab is connected to the casing, which makes the casing energized. The positive tab is connected to the terminal and is insulated from the casing. Because the corners of the casing need to be rounded, the internal space of the casing is reduced, resulting in less space for arranging the positive and negative tabs. This makes it easy for the positive and negative tabs to come into contact or for the positive tab to come into contact with the casing, which can easily cause a short circuit in the battery. Summary of the Invention

[0004] Based on this, this application provides a battery to address the shortcomings of related technologies.

[0005] The battery provided in this application includes:

[0006] The battery cell includes: a first electrode and a second electrode; the first electrode includes a first current collector and a first tab extending from one side of the first current collector, and the second electrode includes a second current collector and a second tab extending from one side of the second current collector; the first tab and the second tab are both located on one side of the battery cell along a first direction, and the first tab and the second tab are spaced apart along a second direction.

[0007] The housing contains the battery cell. The housing includes a first housing wall, a transition wall, and a second housing wall and a third housing wall disposed opposite to each other along a second direction. The transition wall, the second housing wall, and the third housing wall are all arc-shaped. The first housing wall and the second housing wall are connected by the transition wall.

[0008] The first electrode tab is positioned closer to the second shell wall than the second electrode tab;

[0009] The maximum distance D1 between the first lug and the second shell wall, and the radius of curvature R1 of the transition wall, satisfy: 1.5≤D1 / R1≤3.

[0010] In one possible implementation, one end of the transition wall is tangent to the first shell wall, and the other end of the transition wall is tangent to the second shell wall. D1 is the distance from the point of tangency between the second shell wall and the transition wall to the first tab.

[0011] In one possible implementation, the third shell wall is positioned relative to the second shell wall near the center of curvature of the shell;

[0012] And / or, the third shell wall and the second shell wall are arranged concentrically;

[0013] And / or, the radius of curvature R3 of the third shell wall and the radius of curvature R2 of the second shell wall satisfy: 5mm < R2 < R3 < 100mm;

[0014] And / or, the wall thickness of the shell is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

[0015] In one possible implementation, the first current collector has a first side on the side near the third shell wall, and the first electrode has a second side and a third side on the side along the second direction. The first side, the second side and the third side are adjacent to each other in sequence, and at least one of the first side and the second side extends along an arc.

[0016] And / or, the first current collector has a fourth side on the side near the first shell wall, and the first electrode has a fifth side and a sixth side on the side near the first shell wall, the fifth side extending along an arc, and the fourth side, the fifth side and the sixth side being adjacent to each other in sequence.

[0017] In one possible implementation, the first side and the second side extend along an arc and are tangent to each other;

[0018] And / or, the maximum distance D2 from the third side to the first side, the radius of curvature R4 of the first side, and the radius of curvature R5 of the second side satisfy: D2 < R4 + R5.

[0019] And / or, the radius of curvature R4 of the first side and the radius of curvature R5 of the second side satisfy: R5 < R4.

[0020] In one possible implementation, the fifth side extends along an elliptical arc, with the semi-major axis of the fifth side being a and the semi-minor axis being b, where a and b satisfy: a / b≥1.5.

[0021] In one possible implementation, the first current collector has a seventh side and an eighth side, which are arranged opposite to each other along a second direction. The eighth side is arranged near the curvature center of the shell relative to the seventh side. The curvature radius R6 of the seventh side, the curvature radius R7 of the eighth side, and the width W1 of the first tab satisfy: 0.05≤W1 / (R6-R7)≤0.4.

[0022] In one possible implementation, the shell further includes a fourth shell wall located on one side of the shell along a third direction, and the first shell wall, transition wall and second shell wall are all connected to the fourth shell wall.

[0023] The fourth shell wall is provided with a liquid injection hole, and the projection of the second electrode tab on the fourth shell wall at least partially coincides with the liquid injection hole.

[0024] In one possible implementation, the battery further includes a terminal post, a first housing wall having a terminal post hole, the terminal post being disposed in the terminal post hole and extending into the housing, the terminal post being insulated from the first housing wall, and a first tab being connected to the terminal post.

[0025] The electrode post has a countersunk hole, and the distance T from the surface of the electrode post facing the tab to the bottom of the countersunk hole satisfies: 0.05mm≤T≤0.3mm.

[0026] In one possible implementation, the first electrode further includes a first active layer, which is disposed on at least one side in the thickness direction of the first current collector;

[0027] The second electrode also includes a second active layer, which is disposed on at least one side of the thickness direction of the second current collector. The second active layer includes a silicon-based material, and the silicon content in the second active layer is greater than or equal to 5% and less than or equal to 50% based on the total mass of the second active layer.

[0028] The battery provided in this application embodiment includes a battery cell and a casing. The battery cell includes a first electrode and a second electrode. The first electrode includes a first current collector and a first tab. The second electrode includes a second current collector and a second tab. The casing includes a first casing wall, a transition wall, a second casing wall, and a third casing wall. The battery cell is used to store and release electrical energy. The casing is used to encapsulate the battery cell. The first and second current collectors are used to collect current. The first tab is used to transmit the current from the first current collector, and the second tab is used to transmit the current from the second current collector. The transition wall is a rounded corner formed by the casing. The transition wall connects the first and second casing walls, or connects the first and third casing walls, thereby improving the structural strength and aesthetics of the casing.

[0029] Since the second electrode is connected to the first shell wall, the first shell wall becomes conductive, and the first electrode is close to the first shell wall, the transition wall, and the second shell wall.

[0030] If D1 / R1 is less than 1.5, on the one hand, it will cause the radius of curvature R1 of the transition wall to be too large, which will lead to the transition wall being too close to the first tab. During the battery drop test, the impact force will easily cause the first tab to contact the transition wall, resulting in a short circuit. During the charging and discharging process, the cell expansion will easily cause the first tab to contact the transition wall, resulting in a short circuit. On the other hand, it will cause the maximum distance D1 between the first tab and the second shell wall to be too small, which will cause the first tab to be too close to the second shell wall. During the battery drop test, the first tab will easily contact the second shell wall, resulting in a short circuit. During the charging and discharging process, the cell expansion will easily cause the first tab to contact the second shell wall, resulting in a short circuit.

[0031] If D1 / R1 is greater than 3, it will increase the distance between the first tab and the casing. Since the internal space of the casing is limited, this will reduce the distance between the first tab and the second tab. During the battery drop test, the first tab and the second tab are likely to come into contact, causing a short circuit in the battery. Also, during the charging and discharging process, the expansion of the battery cell can easily cause the second tab to come into contact with the first tab, causing a short circuit in the battery.

[0032] In this embodiment, D1 / R1 is between 1.5 and 3, which makes the positional relationship between the first tab, the second tab and the casing reasonable, thereby preventing the first tab from being too close to the casing and the first tab from being too close to the second tab, thus preventing the first tab from contacting the casing and the first tab from contacting the second tab, thereby effectively improving the safety performance of the battery.

[0033] In addition to the technical problems solved by the embodiments of this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that the battery provided by this application can solve, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific embodiments. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the battery structure provided in an embodiment of this application;

[0036] Figure 2 This is a schematic diagram of the battery casing provided in an embodiment of this application;

[0037] Figure 3 This is a schematic diagram of the structure of the first electrode and the second electrode in the battery provided in the embodiments of this application;

[0038] Figure 4 A partial structural diagram of the battery provided in an embodiment of this application;

[0039] Figure 5 This is a schematic diagram of the structure of the first electrode in the battery provided in an embodiment of this application;

[0040] Figure 6 This is yet another structural schematic diagram of the first electrode in the battery provided in an embodiment of this application;

[0041] Figure 7 Another structural schematic diagram of the first and second electrodes in a battery provided in this application embodiment;

[0042] Figure 8 This is another partial structural schematic diagram of the battery provided in an embodiment of this application;

[0043] Figure 9 This is another partial structural schematic diagram of the battery provided in an embodiment of this application.

[0044] Explanation of reference numerals in the attached figures:

[0045] 100-cell;

[0046] 110 - First electrode; 111 - First current collector; 1111 - First side; 1112 - Fourth side; 1113 - Seventh side; 1114 - Eighth side;

[0047] 112-First pole lug; 1121-Second side; 1122-Third side; 1123-Fifth side; 1124-Sixth side;

[0048] 120 - Second electrode plate; 121 - Second current collector; 122 - Second electrode tab;

[0049] 130 - Diaphragm;

[0050] 200 - Shell; 210 - First shell wall; 220 - Transition wall; 230 - Second shell wall; 240 - Third shell wall; 250 - Fourth shell wall; 251 - Injection hole; 260 - Fifth shell wall; 270 - Sixth shell wall;

[0051] 300 - pole post; 310 - countersunk hole. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0053] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0054] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0055] The terms "first," "second," and "third" (if any) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0056] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or display that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or display.

[0057] The battery compartment space of smart wearable devices (such as smartwatches, health monitoring bracelets, AR / VR devices, etc.) is often limited by ergonomic design and appearance requirements, resulting in a curved shape. This necessitates the use of batteries with corresponding curvature to power them. In related technologies, the battery consists of a cell and a casing, both of which are curved. One side of the cell has a positive and a negative tab. The negative tab connects to the casing, thus energizing the casing. The positive tab connects to the terminal and is insulated from the casing. Because the corners of the casing need to be rounded, the internal space of the casing is reduced, resulting in less space for the positive and negative tabs. This makes it easier for the positive and negative tabs to come into contact, or for the positive tab to contact the casing, potentially causing a short circuit.

[0058] In view of the above problems, embodiments of this application provide a battery that, by increasing the maximum distance D between the first electrode tab and the second shell wall... 1、The ratio of the curvature radius R1 of the transition wall to that of the first and second tabs is set between 1.5 and 3 to reasonably design the spacing between the first and second tabs, as well as the spacing between the first tab and the casing, thereby preventing short circuits caused by contact between the first and second tabs and between the first tab and the casing.

[0059] The specific implementation of the battery provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0060] Reference Figures 1 to 4 As shown, the battery provided in this embodiment includes a battery cell 100 and a casing 200. The battery cell 100 is housed within the casing 200. The battery cell 100 includes a first electrode 110, a second electrode 120, and a separator 130 located between the first electrode 110 and the second electrode 120. The first electrode 110 includes a first current collector 111 and a first tab 112 extending from one side of the first current collector 111. The second electrode 120 includes a second current collector 121 and a second tab 122 extending from one side of the second current collector 121. The first tab 112 and the second tab 122 are both located on one side of the battery cell 100 along a first direction, and the first tab 112 and the second tab 122 are spaced apart along a second direction.

[0061] The housing 200 includes a first housing wall 210, a transition wall 220, and a second housing wall 230 and a third housing wall 240 disposed opposite to each other along a second direction. The transition wall 220, the second housing wall 230, and the third housing wall 240 are all arc-shaped. The curvature centers of the second housing wall 230 and the third housing wall 240 are located on the same side. The transition wall 220 connects the first housing wall 210 and the second housing wall 230, and the transition wall 220 connects the first housing wall 210 and the third housing wall 240.

[0062] The first tab 112 is positioned close to the second shell wall 230 relative to the second tab 122. The maximum distance D1 between the first tab 112 and the second shell wall 230 and the radius of curvature R1 of the transition wall 220 satisfy: 1.5≤D1 / R1≤3.

[0063] The battery in this embodiment is arc-shaped, that is, both the cell 100 and the casing 200 are arc-shaped. The first direction is the circumferential direction of the battery, which can be referred to as the X direction in the attached figure. The second direction is the radial direction of the battery, which can be referred to as the Y direction in the attached figure. The third direction is the axial direction of the battery, which can be referred to as the Z direction in the attached figure.

[0064] The first shell wall 210 extends along the Y direction, while the second shell wall 230 and the third shell wall 240 both extend along the X direction.

[0065] In this embodiment, one of the first electrode 110 and the second electrode 120 is a positive electrode and the other is a negative electrode. For example, the first electrode 110 is a positive electrode and the second electrode 120 is a negative electrode, or the first electrode 110 is a negative electrode and the second electrode 120 is a positive electrode.

[0066] The battery provided in this embodiment includes a battery cell 100 and a casing 200. The battery cell 100 includes a first electrode 110 and a second electrode 120. The first electrode 110 includes a first current collector 111 and a first tab 112. The second electrode 120 includes a second current collector 121 and a second tab 122. The casing 200 includes a first casing wall 210, a transition wall 220, a second casing wall 230, and a third casing wall 240. The battery cell 100 is used to store and release electrical energy. The casing 200 is used to encapsulate the battery cell 100. The first current collector 111 and the second current collector 121 are used to collect current. The first tab 112 is used to transmit the current of the first current collector 111, and the second tab 122 is used to transmit the current of the second current collector 121. The transition wall 220 is a rounded corner formed at the corner of the shell 200. By setting the transition wall 220 to connect the first shell wall 210 and the second shell wall 230, or to connect the first shell wall 210 and the third shell wall 240, the structural strength and aesthetics of the shell 200 are improved.

[0067] Since the second tab 122 is connected to the first shell wall 210, the first shell wall 210 becomes conductive. The first tab 112 is close to the first shell wall 210, the transition wall 220, and the second shell wall 230. The first tab 112 cannot come into contact with any of the first shell wall 210, the transition wall 220, or the second shell wall 230, otherwise it will cause a short circuit in the battery.

[0068] If D1 / R1 is less than 1.5, on the one hand, it will cause the radius of curvature R1 of the transition wall 220 to be too large, which will cause the transition wall 220 to be too close to the first tab 112. During the battery drop test, the impact force may cause the first tab 112 to contact the transition wall 220, resulting in a short circuit. During the charging and discharging process, the expansion of the cell 100 may cause the first tab 112 to contact the transition wall 220, resulting in a short circuit. On the other hand, it will cause the maximum distance D1 between the first tab 112 and the second shell wall 230 to be too small, which will cause the first tab 112 to be too close to the second shell wall 230. During the battery drop test, the first tab 112 may contact the second shell wall 230, resulting in a short circuit. During the charging and discharging process, the expansion of the cell 100 may cause the first tab 112 to contact the second shell wall 230, resulting in a short circuit.

[0069] If D1 / R1 is greater than 3, the distance between the first tab 112 and the casing 200 will increase. Since the internal space of the casing 200 is limited, this will reduce the distance between the first tab 112 and the second tab 122. During battery drop tests, this could easily cause the first tab 112 to contact the second tab 122, resulting in a battery short circuit. Furthermore, during charging and discharging, the expansion of the cell 100 could easily cause the second tab 122 to contact the first tab 112, also resulting in a battery short circuit. The distance between the first tab 112 and the second tab 122 in the second direction can be controlled between 1mm and 2mm, thus providing space for the expansion of the cell 100 and preventing short circuits between the first tab 112 and the second tab 122.

[0070] In this embodiment, D1 / R1 is between 1.5 and 3, which makes the positional relationship of the first tab 112, the second tab 122 and the housing 200 reasonable, thereby preventing the first tab 112 from being too close to the housing 200 and the first tab 112 from being too close to the second tab 122, thus preventing the first tab 112 from contacting the housing 200 and the first tab 112 from contacting the second tab 122, thereby effectively improving the safety performance of the battery.

[0071] In some embodiments, one end of the transition wall 220 extending in the direction of extension is tangent to the first shell wall 210, and the other end of the transition wall 220 extending in the direction of extension is tangent to the second shell wall 230. D1 is the distance from the point of tangency between the second shell wall 230 and the transition wall 220 to the first tab 112.

[0072] Thus, the two ends of the extension direction of the transition wall 220 are tangent to the first shell wall 210 and the second shell wall 230, respectively, ensuring that no stress concentration occurs at the connection between the transition wall 220 and the shell wall. One measurement point of D1 is the tangent point between the second shell wall 230 and the transition wall 220. The distance between this point and the first tab 112 is defined as D1. This clarifies the ratio of the radius of curvature R1 of the transition wall 220 to D1, which is beneficial for accurately controlling the distance between the first tab 112 and the shell 200 and avoiding calculation deviations in D1. This makes the optimization of the distance between the first tab 112 and the second shell wall 230 more repeatable and feasible.

[0073] Reference Figure 2 As shown, in some embodiments, the third shell wall 240 and the second shell wall 230 are concentrically arranged, with the third shell wall 240 positioned relative to the second shell wall 230 near the center of curvature of the shell 200, and the radius of curvature R of the second shell wall 230 being... 2、 The radius of curvature R3 of the third shell wall 240 satisfies: 5mm < R2 < R3 < 100mm.

[0074] It should be noted that for regular circular arcs, the center of curvature refers to the center of the arc, and the radius of curvature refers to the radius of the arc. For other arcs, a osculating circle can be used to fit each point on the arc. The radius of curvature is the radius of this osculating circle, and the center of curvature is the center of this osculating circle. For example, three points on the arc can be arbitrarily selected, their radii of curvature can be calculated, and the average of the radii of curvature of these three points can be taken as the radius of curvature of the arc.

[0075] In this embodiment, the second shell wall 230 and the third shell wall 240 can extend along an arc, and the second shell wall 230 and the third shell wall 240 are concentrically arranged, which helps to maintain the geometric consistency of the second shell wall 230 and the third shell wall 240, facilitates the processing and forming of the shell 200, and reduces stress concentration in the shell 200. In the second direction, the shell 200 can provide a more uniform arrangement space for the first electrode 110 and the second electrode 120, avoiding local compression or misalignment of the first electrode 110 and the second electrode 120, thereby reducing the risk of contact between the first electrode tab 112 and the shell 200. The difference between the radius of curvature R3 of the third shell wall 240 and the radius of curvature R2 of the second shell wall 230 determines the distance between the third shell wall 240 and the second shell wall 230, and thus determines the size of the shell 200 in the second direction. In a specific embodiment, the size of the shell 200 in the second direction can be set according to the size of the cell 100 in the second direction.

[0076] For example, the radius of curvature R2 of the second shell wall 230 can be any one of 5mm, 10mm, 15mm, 20mm, 50mm, 90mm or within any two of the values, and the radius of curvature R3 of the third shell wall 240 can be any one of 10mm, 20mm, 50mm, 80mm, 90mm, 100mm or within any two of the values.

[0077] It should be understood that, since both the second shell wall 230 and the third shell wall 240 have a certain thickness, the radius of curvature R2 of the second shell wall 230 can be the inner diameter of the second shell wall 230, the outer diameter of the second shell wall 230, or the average of the inner and outer diameters of the second shell wall 230. Similarly, the radius of curvature R3 of the third shell wall 240 can be the inner diameter of the third shell wall 240, the outer diameter of the third shell wall 240, or the average of the inner and outer diameters of the third shell wall 240.

[0078] In some embodiments, the wall thickness of the housing 200 is greater than or equal to 0.05 mm and less than or equal to 0.5 mm. It is understood that, within the allowable tolerance or error range, the wall thicknesses of the various shell walls of the housing 200, such as the first shell wall 210, the second shell wall 230, the third shell wall 240, and the transition wall 220, are equal. That is, the wall thicknesses of the first shell wall 210, the second shell wall 230, the third shell wall 240, and the transition wall 220 are all between 0.05 mm and 0.5 mm. This prevents excessive wall thickness from reducing the internal space of the housing 200 and facilitates control of the radius of curvature of the transition wall 220, thereby preventing the first tab 112 from contacting the housing 200. Furthermore, it prevents excessively thin wall thickness from reducing the strength of the housing 200.

[0079] For example, the wall thickness can be any one of 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm, or fall within any two of these values.

[0080] Reference Figure 5 and Figure 6 As shown, in some embodiments, the first current collector 111 has a first side 1111 on the side near the third shell wall 240, and the first electrode 112 has a second side 1121 and a third side 1122 on the side along the second direction. The first side 1111, the second side 1121 and the third side 1122 are adjacent to each other in sequence. The first side 1111 and the second side 1121 extend along an arc, and the third side 1122 extends along a straight line.

[0081] The first current collector 111 has a fourth side 1112 on the side near the first shell wall 210, and the first electrode 112 has a fifth side 1123 and a sixth side 1124 on the side near the first shell wall 210. The fifth side 1123 extends along an arc, and the fourth side 1112 and the sixth side 1124 extend along a straight line. The fourth side 1112, the fifth side 1123 and the sixth side 1124 are adjacent to each other in sequence.

[0082] It should be understood that the first current collector 111 and the first tab 112 are integrally formed. Aluminum foil can be used as the master sheet, and the master sheet can be die-cut to process the first current collector 111 and the first tab 112 in one go. During die-cutting, the junction of the first current collector 111 and the first tab 112 can be rounded to prevent stress concentration when the first tab 112 is formed by die-cutting, thereby preventing the first tab 112 from breaking.

[0083] Reference Figure 6As shown, in some embodiments, the first side 1111 and the second side 1121 extend along an arc and are tangent to each other. The maximum distance D2 between the third side 1122 and the first side 1111, the radius of curvature R4 of the first side 1111, and the radius of curvature R5 of the second side 1121 satisfy: D2 < R4 + R5.

[0084] It should be noted that the first current collector 111 has a seventh side 1113 and an eighth side 1114. The seventh side 1113 and the eighth side 1114 are arranged opposite each other along the second direction. The eighth side 1114 is arranged near the curvature center of the housing 200 relative to the seventh side 1113, and the eighth side 1114 is adjacent to the first side 1111. The maximum distance D2 between the third side 1122 and the first side 1111 is the distance from the point of tangency between the first side 1111 and the eighth side 1114 to the third side 1122 along the extension direction of the third side 1122.

[0085] Since D2 < R4 + R5, the two arc segments of the first side 1111 and the second side 1121 can be tangent, and there is no need to use a straight line to connect them. This can prevent the first side 1111 from protruding out of the eighth side 1114, and thus prevent the first side 1111 from contacting the casing 200, thereby reducing the risk of battery short circuit.

[0086] In some embodiments, the radius of curvature R4 of the first side 1111 and the radius of curvature R5 of the second side 1121 also satisfy: R5 < R4.

[0087] It should be understood that when both the first side 1111 and the second side 1121 are circular arcs, the radius of curvature R4 of the first side 1111 is greater than the radius of curvature R5 of the second side 1121. When the first side 1111 is circular arc and the second side 1121 is elliptical arc, the radius of curvature R4 of the first side 1111 is greater than the radius of curvature R5 of the second side 1121. The radius of curvature R5 of the second side 1121 can be the semi-major axis, semi-minor axis, or the average of the semi-major axis and semi-minor axis of the second side 1121.

[0088] Because the radius of curvature of the first side 1111 is greater than that of the second side 1121, and the first side 1111 protrudes outward toward the first current collector 111 while the second side 1121 is recessed inward toward the first tab 112, the width of the first tab 112 can be reduced, thereby increasing the distance between the first tab 112 and the second shell wall 230, thus preventing a short circuit in the battery. Furthermore, this also ensures that the second electrode 120 fully covers and extends beyond the first electrode 110, thereby preventing lithium plating on the second electrode 120.

[0089] Reference Figures 5 to 7 As shown, in some embodiments, the fifth side 1123 extends along an elliptical arc, the semi-major axis of the fifth side 1123 is a, the semi-minor axis of the fifth side 1123 is b, and a and b satisfy: a / b≥1.5.

[0090] In other words, when the fifth side 1123 extends along the elliptical arc, the distance between the points of tangency between the fifth side 1123 and the sixth side 1124, and the points of tangency between the fifth side 1123 and the fourth side 1112 along the extension direction of the sixth side 1124 is the semi-major axis a of the fifth side 1123, and the distance between the points of tangency between the fifth side 1123 and the sixth side 1124, and the points of tangency between the fifth side 1123 and the fourth side 1112 along the extension direction of the fourth side 1112 is the semi-minor axis b of the fifth side 1123.

[0091] Compared to rounded chamfers, setting the fifth side 1123 as an elliptical chamfer can reduce the stress concentration of the fifth side 1123, thereby increasing the structural strength of the first tab 112, preventing the root of the first tab 112 from breaking, and thus improving the structural performance and service life of the cell 100.

[0092] Reference Figure 3 , Figure 5 , Figure 6 As shown, in some embodiments, the first current collector 111 has a seventh side 1113 and an eighth side 1114, the seventh side 1113 and the eighth side 1114 are arranged opposite each other along a second direction, and the eighth side 1114 is arranged near the curvature center of the housing 200 relative to the seventh side 1113. The curvature radius R6 of the seventh side 1113, the curvature radius R7 of the eighth side 1114, and the width W1 of the first tab 112 satisfy: 0.05≤W1 / (R6-R7)≤0.4.

[0093] Understandably, the difference between the radius of curvature R6 of the seventh side 1113 and the radius of curvature R7 of the eighth side 1114 determines the width of the first current collector 111. The width of the first tab 112 needs to be matched with the width of the first current collector 111 to ensure the flow capacity of the first tab 112.

[0094] In this embodiment, the ratio of the width of the first tab 112 to the width of the first current collector 111 is between 0.05 and 0.4. This ensures that the width of the first tab 112 is not too small, thereby improving the structural strength of the first tab 112 and ensuring its current-carrying capacity, which in turn improves the battery's electrical performance. Furthermore, the width of the first tab 112 is not too large, which helps control the distance between the first tab 112 and the second tab 122, thus preventing contact between them.

[0095] For example, the ratio of the width of the first electrode 112 to the width of the first current collector 111 can be any one of 0.05, 0.1, 0.15, 0.2, 0.3, 0.4 or fall within any two value ranges.

[0096] It should be noted that the ratio of the width W1 of the second tab 122 to the width of the second current collector 121 is also between 0.05 and 0.4, in order to ensure the overcurrent capacity of the second tab 122 and to prevent the second tab 122 from contacting the first tab 112 and causing a short circuit in the battery.

[0097] Reference Figure 1 and Figure 8 As shown, in one possible implementation, the housing 200 further includes a fourth housing wall 250, which is located on one side of the housing 200 along a third direction. The first housing wall 210, the transition wall 220, and the second housing wall 230 are all connected to the fourth housing wall 250. The fourth housing wall 250 is provided with a liquid injection hole 251, and the projection of the second electrode 122 on the fourth housing wall 250 at least partially coincides with the liquid injection hole 251.

[0098] Thus, the injection hole 251 is positioned close to the second tab 122. Since the first tab 112 needs to be connected to the post 300, the post 300 will occupy part of the space inside the housing 200. The second tab 122 is welded to the first housing wall 210, and the location of the second tab 122 has a larger space, which is more conducive to the injection operation and can improve the wetting effect of the electrolyte.

[0099] Reference Figure 1 and Figure 2 As shown, the housing 200 of this embodiment has six surfaces. The housing 200 may also include a fifth housing wall 260 and a sixth housing wall 270. The first housing wall 210, the second housing wall 230, the third housing wall 240, the fourth housing wall 250, the fifth housing wall 260 and the sixth housing wall 270 respectively form the six surfaces of the housing 200. The first housing wall 210 and the fifth housing wall 260 are arranged opposite each other along a first direction, and the fourth housing wall 250 and the sixth housing wall 270 are arranged opposite each other along a third direction.

[0100] The first shell wall 210 and the second shell wall 230, the first shell wall 210 and the third shell wall 240, the second shell wall 230 and the fifth shell wall 260, and the third shell wall 240 and the fifth shell wall 260 can all be connected by transition walls 220, which helps to reduce the stress on the shell 200.

[0101] Reference Figure 9As shown, in one possible implementation, the battery further includes a terminal post 300. The first housing wall 210 has a hole for the terminal post 300. The terminal post 300 is disposed in the hole and extends into the housing 200. The terminal post 300 is insulated from the first housing wall 210. A first tab 112 is connected to the terminal post 300. The terminal post 300 has a countersunk hole 310. The distance T from the surface of the terminal post 300 facing the tab to the bottom of the countersunk hole 310 satisfies: 0.05mm ≤ T ≤ 0.3mm.

[0102] For example, the first tab 112 and the electrode post 300 are connected by laser welding. This can be achieved by first attaching the second tab 122 to the surface of the electrode post 300 facing the tab, and then using a laser to perform laser welding inside the countersunk hole 310, thereby achieving a fixed connection between the first pin and the electrode post 300. Along the length of the cell 100, the distance from the bottom surface of the countersunk hole 310 to the bottom surface of the electrode post 300 is T, and T satisfies: 0.05mm ≤ T ≤ 0.3mm. By forming a countersunk hole 310 on the electrode post 300 and controlling the distance T from the surface of the electrode post 300 facing the tab to the bottom of the countersunk hole 310 to between 0.05mm and 0.3mm, it is beneficial to ensure that the welding energy can penetrate the electrode post 300 to connect the electrode post 300 and the first tab 112, and it also helps to improve the structural strength of the electrode post 300.

[0103] For example, T can be any value among 0.05mm, 0.1mm, 0.15mm, 0.2mm, and 0.3mm, or fall within the range of any two values.

[0104] In one possible implementation, the first electrode 110 further includes a first active layer disposed on at least one side of the first current collector 111 in the thickness direction. The second electrode 120 further includes a second active layer disposed on at least one side of the second current collector 121 in the thickness direction. The second active layer comprises a silicon-based material, and the silicon content in the second active layer is greater than or equal to 5% and less than or equal to 50% based on the total mass of the second active layer.

[0105] For example, silicon-based materials may include silicon-carbon composite materials, silicon-oxygen materials, silicon-based alloy materials, etc. This embodiment does not limit this. Using silicon-based materials as the active material of the second active layer can effectively improve the energy density of the second electrode 120. Moreover, the silicon content is controlled within 50%, which can prevent the second electrode 120 from expanding too much and causing the second tab 122 to contact the first tab 112, thereby preventing short circuits in the battery during cycling.

[0106] The battery can be a lithium-ion rechargeable battery.

[0107] The present invention will be described in detail below through embodiments. The embodiments described herein are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0108] The following examples illustrate the battery of the present invention.

[0109] Example 1

[0110] Using the first electrode 110 as the positive electrode and the second electrode 120 as the negative electrode, a battery is prepared according to the following method:

[0111] (1) Preparation of positive electrode sheet

[0112] Lithium cobalt oxide, a positive electrode conductive agent (conductive carbon black and carbon nanotubes mixed at a mass ratio of 2:1), and a positive electrode binder (polyvinylidene fluoride) are mixed at a mass ratio of 97:1.5:1.5. N-methylpyrrolidone (NMP) is added, and the mixture is stirred evenly to prepare a positive electrode slurry. The positive electrode slurry is coated on the surface of aluminum foil, and after drying and rolling, a positive electrode sheet is obtained.

[0113] (2) Preparation of negative electrode sheet

[0114] Artificial graphite, silicon-carbon materials (including porous carbon matrix and silicon material located in the pores inside the porous carbon matrix), carbon nanotubes, lithium carboxymethyl cellulose, styrene-butadiene rubber and polyacrylic acid are mixed in a mass ratio of 87.7:9.2:0.5:0.8:0.5:1.3, and deionized water is added to prepare a negative electrode slurry. The negative electrode slurry is coated on both sides of a copper foil, and after drying and rolling, a negative electrode sheet is obtained.

[0115] The elemental silicon content in the negative electrode active coating is 5.5%.

[0116] (3) Preparation of electrolyte

[0117] In an argon-filled glove box (moisture <1 ppm, oxygen <1 ppm), organic solvents (ethylene carbonate, propylene carbonate, propyl propionate, and ethyl propionate in a mass ratio of 15:15:50:20, totaling 71.5 parts by weight) were mixed to form a homogeneous solvent. Then, 15.5 parts by weight of lithium salt (LiPF6), 2 parts by weight of 1,3-propanesulfonyl lactone, 3 parts by weight of 1,3,6-hexanetrionitrile, and 8 parts by weight of fluoroethylene carbonate were slowly added. After thorough stirring, the desired lithium-ion battery electrolyte was obtained.

[0118] (4) Preparation of diaphragm 130

[0119] Polyethylene was selected as the 5μm substrate layer and polyvinylidene fluoride was selected as the adhesive layer. An alumina ceramic layer with a thickness of 2μm was set on the side of the adhesive layer close to the substrate layer to obtain a porous membrane 130.

[0120] (5) Battery fabrication

[0121] The positive electrode sheet prepared in step (1), the separator 130 prepared in step (4), and the negative electrode sheet prepared in step (2) are stacked to obtain a core. The core is then packaged, baked, injected with electrolyte, formed, resealed, sorted, and subjected to OCV to obtain a battery. Specifically, D1 / R1=1.5.

[0122] Example 2

[0123] The same procedure was followed as in Example 1, except that D1 / R1 = 2.

[0124] Example 3

[0125] The same procedure was followed as in Example 1, except that D1 / R1 = 3.

[0126] Comparative Example 1

[0127] The same procedure was followed as in Example 1, except that D1 / R1 = 1.

[0128] Comparative Example 2

[0129] The same procedure was followed as in Example 1, except that D1 / R1 = 3.5.

[0130] The following is a brief description of the relevant tests for the batteries in the embodiments of this application.

[0131]

[0132] I. Loop Testing

[0133] Charge at a constant current of 18A to 4.3V (current cutoff, cutoff current 2C), then charge at a constant current of 2C to 4.45V (current cutoff, cutoff current 1.5C), then charge at a constant current of 1.5C to 4.53V (current cutoff, cutoff current 1.2C), and finally charge at a constant current of 1.2C to 4.58V (constant current cutoff, cutoff current 0.05C). Then discharge at 1C to 3V and record the discharged capacity as the capacity for this cycle. Allow a 5-minute rest period between each charge / discharge step. Repeat the above cycle 600 times.

[0134] II. Drop Test

[0135] In an environment of 25℃±5℃, the battery is discharged at 0.2C to the lower limit voltage, left to stand for 10 minutes, charged at 1C to the upper limit voltage, cut off at 0.02C, and left to stand for 10 minutes. The fully charged battery is then dropped freely from a height of 1 meter onto a concrete slab or metal floor.

[0136] It should be noted that the standard for passing the cycle test is that the battery does not catch fire or explode after 600 cycles; otherwise, it fails. The standard for passing the drop test is that when a fully charged battery is dropped freely from a height of 1 meter onto a concrete slab or metal floor, the battery does not catch fire or explode; otherwise, it fails. Examples 1 to 3, Comparative Example 1, and Comparative Example 2 all tested 10 batteries, and the pass rate was calculated.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery, characterized in that, include: The battery cell includes: a first electrode and a second electrode; The first electrode includes a first current collector and a first tab extending from one side of the first current collector; the second electrode includes a second current collector and a second tab extending from one side of the second current collector; the first tab and the second tab are both located on one side of the cell along a first direction, and the first tab and the second tab are spaced apart along a second direction. The housing contains the battery cell. The housing includes a first shell wall, a transition wall, and a second shell wall and a third shell wall disposed opposite to each other along the second direction. The transition wall, the second shell wall, and the third shell wall are all arc-shaped. The first shell wall and the second shell wall are connected through the transition wall. The first electrode tab is positioned closer to the second shell wall than the second electrode tab; The maximum distance D1 between the first electrode and the second shell wall and the radius of curvature R1 of the transition wall satisfy: 1.5≤D1 / R1≤3.

2. The battery according to claim 1, characterized in that, One end of the transition wall is tangent to the first shell wall, and the other end of the transition wall is tangent to the second shell wall. D1 is the distance from the point of tangency between the second shell wall and the transition wall to the first tab.

3. The battery according to claim 1 or 2, characterized in that, The third shell wall is positioned relative to the second shell wall near the center of curvature of the shell; And / or, the third shell wall and the second shell wall are concentrically arranged; And / or, the radius of curvature R3 of the third shell wall and the radius of curvature R2 of the second shell wall satisfy: 5mm < R2 < R3 < 100mm; And / or, the wall thickness of the shell is greater than or equal to 0.05 mm and less than or equal to 0.5 mm.

4. The battery according to claim 3, characterized in that, The first current collector has a first side edge on the side near the third shell wall, and the first electrode has a second side edge and a third side edge on the side along the second direction. The first side edge, the second side edge and the third side edge are adjacent to each other in sequence, and at least one of the first side edge and the second side edge extends along an arc. And / or, the first current collector has a fourth side on the side near the first shell wall, and the first electrode has a fifth and a sixth side on the side near the first shell wall, the fifth side extending along an arc, and the fourth, fifth and sixth sides being adjacent to each other in sequence.

5. The battery according to claim 4, characterized in that, The first side and the second side extend along an arc, and the first side and the second side are tangent to each other; And / or, the maximum distance D2 between the third side and the first side, the radius of curvature R4 of the first side, and the radius of curvature R5 of the second side satisfy: D2 < R4 + R5. And / or, the radius of curvature R4 of the first side and the radius of curvature R5 of the second side satisfy: R5 < R4.

6. The battery according to claim 5, characterized in that, The fifth side extends along an elliptical arc, with a semi-major axis of the fifth side and b semi-minor axis, where a and b satisfy: a / b≥1.

5.

7. The battery according to claim 1 or 2, characterized in that, The first current collector has a seventh side and an eighth side, which are arranged opposite to each other along the second direction. The eighth side is arranged near the curvature center of the housing relative to the seventh side. The curvature radius R6 of the seventh side, the curvature radius R7 of the eighth side, and the width W1 of the first tab satisfy: 0.05≤W1 / (R6-R7)≤0.

4.

8. The battery according to claim 1 or 2, characterized in that, The housing further includes a fourth shell wall, which is located on one side of the housing along a third direction. The first shell wall, the transition wall, and the second shell wall are all connected to the fourth shell wall. The fourth shell wall is provided with a liquid injection hole, and the projection of the second electrode on the fourth shell wall at least partially coincides with the liquid injection hole.

9. The battery according to claim 1 or 2, characterized in that, It also includes a pole post, the first shell wall is provided with a pole post hole, the pole post is disposed in the pole post hole and extends into the shell, the pole post is insulated from the first shell wall, and the first electrode tab is connected to the pole post; The pole post is provided with a countersunk hole, and the distance T from the surface of the pole post facing the tab to the bottom of the countersunk hole satisfies: 0.05mm≤T≤0.3mm.

10. The battery according to claim 1 or 2, characterized in that, The first electrode further includes a first active layer, which is disposed on at least one side of the first current collector in the thickness direction; The second electrode further includes a second active layer, which is disposed on at least one side of the thickness direction of the second current collector. The second active layer includes a silicon-based material, and the silicon content in the second active layer is greater than or equal to 5% and less than or equal to 50% based on the total mass of the second active layer.

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