Single cell and battery pack

Abstract

Embodiments of the present application relate to the technical field of battery, and specifically disclose a single battery and a battery pack. The single battery comprises a shell with an opening; an electrode assembly arranged in the shell and having a central through hole; an end cover connected to the shell and covering the opening; a pole column penetrating the end cover; a current collecting element comprising a first current collecting part and a second current collecting part, the first current collecting part being arranged between the end cover and the electrode assembly and electrically connected to the electrode assembly, the second current collecting part being connected to a side of the first current collecting part away from the pole column and being inserted into the central through hole; and an overcurrent protection element, a side of the second current collecting part facing the pole column being provided with a receiving groove, at least part of the overcurrent protection element being inserted into the receiving groove, one end of the overcurrent protection element being electrically connected to the second current collecting part, and the other end of the overcurrent protection element being electrically connected to the pole column. According to the present application, the overcurrent protection element can be first fused to cut off the conduction circuit of the single battery, thereby improving the safety performance of the single battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a single cell battery and a battery pack. Background Technology

[0002] With the rapid development of mobile phones, laptops, electric vehicles, power tools, and other electronic devices, rechargeable batteries with high capacity, long cycle life, and high safety performance have been widely used and developed. At the same time, there is an urgent need for rechargeable batteries with even greater capacity, durability, and safety. Safety performance is one of the core performance characteristics of a battery; therefore, how to improve the safety performance of rechargeable batteries has become a pressing issue that needs to be addressed. Utility Model Content

[0003] Embodiments of this application provide a single battery cell and a battery pack to improve the safety performance of the single battery cell.

[0004] To address the aforementioned technical problems, embodiments of this application disclose the following technical solutions:

[0005] On one hand, a single-cell battery is provided, having an axial orientation, comprising:

[0006] The housing has an opening at one end in the axial direction;

[0007] An electrode assembly is disposed within the housing, and the electrode assembly has a central through hole;

[0008] End cap, connecting to the housing and sealing the opening;

[0009] The pole is inserted into the end cap;

[0010] A current collector element, disposed within a housing, includes: a first current collector and a second current collector. The first current collector is disposed between the end cap and the electrode assembly and is electrically connected to the electrode assembly. The second current collector is connected to the side of the first current collector away from the electrode post and is inserted into a central through hole.

[0011] The overcurrent protection element has a receiving groove on the side of the second current collector facing the pole post. At least part of the overcurrent protection element is inserted into the receiving groove. One end of the overcurrent protection element is electrically connected to the second current collector, and the other end of the overcurrent protection element is electrically connected to the pole post.

[0012] In addition to one or more of the features disclosed above, or as an alternative, the overcurrent protection element includes: a fuse, a first electrical connection and a second electrical connection, wherein the fuse, the first electrical connection and the second electrical connection are both disposed in a receiving groove;

[0013] The first electrical connection part is connected to the side of the fuse part near the electrode post, and the first electrical connection part is electrically connected to the electrode post;

[0014] The second electrical connection is connected to the side of the fuse part away from the pole, and the second electrical connection is electrically connected to the second current collector.

[0015] In addition to one or more of the features disclosed above, or alternatively, the single cell also has a radial direction perpendicular to the axial direction;

[0016] The radial dimension of the fused portion is smaller than the radial dimension of the first electrical connection portion, and the radial dimension of the fused portion is smaller than the radial dimension of the second electrical connection portion.

[0017] In addition to one or more of the features disclosed above, or alternatively, the overcurrent protection element also includes a third electrical connection portion connected to the side of the first electrical connection portion near the pole.

[0018] A positioning groove is provided on the side of the pole near the third electrical connection part. The third electrical connection part is embedded in the positioning groove. The third electrical connection part is electrically connected to the first electrical connection part on one side in the axial direction, and electrically connected to the pole on the other side in the axial direction.

[0019] In addition to one or more of the features disclosed above, or alternatively, the single cell also has a radial direction perpendicular to the axial direction;

[0020] The radial dimension of the third electrical connection is larger than the radial dimension of the receiving groove.

[0021] In addition to one or more of the features disclosed above, or as an alternative, the single cell also includes: a first insulating member and a second insulating member, at least a portion of the first insulating member being disposed between the third electrical connection portion and the first current collector portion, and at least a portion of the first insulating member being disposed between the terminal post and the first current collector portion;

[0022] The second insulating element covers the fused portion and also covers the first electrical connection portion.

[0023] In addition to one or more of the features disclosed above, or as an alternative, the second current collector includes: a rigid portion that protrudes from the side of the first current collector away from the pole post;

[0024] An elastic portion is connected to the rigid portion on the side away from the first current collector. On a cross-section passing through the axial direction, the elastic portion is arranged along a broken line or an arc.

[0025] The base portion is connected to the side of the elastic portion away from the first current collector portion, and the base portion is electrically connected to the second electrical connection portion;

[0026] The rigid part, the elastic part, and the bottom support part together form a receiving groove.

[0027] In addition to one or more of the features disclosed above, or as an alternative, the first insulating member has a first outer wall away from the first current collector, and the base portion has a second outer wall close to the elastic portion;

[0028] When the second current collector is not under stress, the total axial dimension of the fuse, the first electrical connection and the second electrical connection is greater than the axial distance between the first outer wall and the second outer wall.

[0029] In addition to one or more of the features disclosed above, or as an alternative, the single cell also includes: a third insulating member, at least a portion of which is disposed between the end cap and the terminal post, and at least a portion of which is disposed between the end cap and the first current collector.

[0030] On the other hand, a battery pack is further disclosed, which, in addition to one or more of the features disclosed above, or alternatively, includes a housing; and individual cells as described in any of the preceding claims, the individual cells being disposed within the housing.

[0031] One of the above technical solutions has the following advantages or beneficial effects: By setting an overcurrent protection element to connect the current collector element and the terminal post, this application ensures that when an external short circuit occurs in a single cell, the overcurrent protection element can melt first to cut off the conduction circuit of the single cell, avoiding the problem of thermal runaway caused by excessive current due to external short circuit leading to heat accumulation in the casing in a short time, thus improving the safety performance of the single cell; at the same time, by setting the second current collector of the current collector element in the central through hole of the electrode assembly, and setting at least part of the overcurrent protection element in the receiving groove of the second current collector element, this application makes full use of the redundant space inside the single cell to install the overcurrent protection element, reduces the space occupied by the overcurrent protection element, increases the space occupancy rate of the electrode assembly in the single cell, and increases the volumetric energy density of the single cell. Attached Figure Description

[0032] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0033] Figure 1 This is a three-dimensional structural view of a single battery cell provided according to an embodiment of this application;

[0034] Figure 2 This is an exploded structural view of a single cell provided according to an embodiment of this application;

[0035] Figure 3 This is a cross-sectional view of a single cell provided according to an embodiment of this application;

[0036] Figure 4This is an exploded cross-sectional view of the pole, current collector, and overcurrent protection element provided according to the embodiments of this application;

[0037] Figure 5 This is a cross-sectional view of the current collector and overcurrent protection element provided according to the embodiments of this application when not under stress.

[0038] Explanation of reference numerals in the attached figures:

[0039] 100. Single cell battery;

[0040] 110. Shell;

[0041] 120. Electrode assembly; 121. Central through hole;

[0042] 130. End cap;

[0043] 140. Pole post; 141. Positioning groove;

[0044] 150. Current collector element; 151. First current collector section; 152. Second current collector section; 1521. Rigid section; 1522. Elastic section; 1523. Base support section; 15231. Second outer wall; 1524. Receiving groove;

[0045] 160. Overcurrent protection element; 161. Fuse; 162. First electrical connection; 163. Second electrical connection; 164. Third electrical connection;

[0046] 171. First insulating component; 1711. First outer wall; 172. Second insulating component; 173. Third insulating component. Detailed Implementation

[0047] To make the objectives, technical solutions, and beneficial effects of this application clearer, the following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates this application. It should be understood that the specific embodiments described in this specification are merely for explaining this application and are not intended to limit it.

[0048] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, 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. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0049] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of 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.

[0050] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0051] Existing secondary batteries generate significant currents when triggered by external short circuits, which can easily lead to thermal runaway, causing fires and explosions. This poses a serious threat to personal and property safety and compromises the battery's safety performance. Furthermore, existing secondary batteries require tolerances during manufacturing and assembly. Additional structures need to be designed during assembly to mitigate the effects of these tolerances. However, these additional structures occupy extra internal space, reducing the space utilization of the electrode components and consequently lowering the battery's volumetric energy density.

[0052] To address the aforementioned problems, this application provides a single-cell battery 100 with a perpendicular axial direction Z and a radial direction X. Exemplarily, in this application, the single-cell battery 100 has mutually perpendicular axial directions Z and X. It should be noted that in all embodiments of this application, the axial direction Z refers to the direction indicated by the arrow in the accompanying drawings; it should be understood that, ideally, when the single-cell battery 100 is correctly and well assembled, the housing 110, electrode assembly 120, end cap 130, and current collector 150 have the same axis, which is parallel to the axial direction Z. Therefore, constructing a cylindrical coordinate system around this axis, the circumferential direction refers to the direction of the tangent to a circle centered at the intersection of the aforementioned axis and the aforementioned plane, on a plane perpendicular to the axial direction Z, and the radial direction X refers to the direction of a ray originating from the intersection of the aforementioned axis and the aforementioned plane within the aforementioned plane.

[0053] It should be understood that the concepts of axial Z, radial X, and circumferential direction are introduced in all embodiments of this application merely for the convenience of describing spatial positional relationships and should not be construed as limiting the scope of the embodiments of this application. Therefore, the positional relationship in which axial Z, radial X, and circumferential direction are mutually perpendicular can be reasonably interpreted, based on the actual technical scenario, as a nearly perpendicular directional relationship between each pair of axial Z, radial X, and circumferential direction. For example, the included angle between each pair of axial Z, radial X, and circumferential direction is in the range of 85°-95°. As long as the technical solution conforms to the spirit of this application or achieves the technical effect described in this application, it can be considered to fall within the scope defined by the appended claims.

[0054] Specifically, refer to Figures 1 to 3 The single cell 100 includes: a casing 110, an electrode assembly 120, an end cap 130, a terminal post 140, a current collector 150, and an overcurrent protection element 160.

[0055] Specifically, the housing 110 has an opening at one end in the Z-axis direction, the electrode assembly 120 is disposed inside the housing 110, and the electrode assembly 120 has a central through hole 121; the end cap 130 is disposed at one end of the housing 110 in the Z-axis direction, the end cap 130 is connected to the housing 110 and seals the opening; the electrode post 140 passes through the end cap 130, and the electrode post 140 is insulated from the end cap 130 to avoid short circuit of the single cell 100 caused by contact between the electrode post 140 and the end cap 130, thus ensuring the normal use of the single cell 100.

[0056] The current collector 150 is disposed within the housing 110 and includes: a first current collector 151 and a second current collector 152. The first current collector 151 is disposed between the end cap 130 and the electrode assembly 120 and is electrically connected to the electrode assembly 120. The second current collector 152 is connected to the side of the first current collector 151 away from the electrode post 140 and is inserted into the central through hole 121. The second current collector 152 is insulated from the electrode assembly 120. A receiving groove 1524 is provided on the side of the second current collector 152 facing the electrode post 140. At least a portion of the overcurrent protection element 160 is inserted into the receiving groove 1524. One end of the overcurrent protection element 160 is electrically connected to the second current collector 152, and the other end of the overcurrent protection element 160 is electrically connected to the electrode post 140. The second current collector 152 is electrically connected to the terminal post 140 via the overcurrent protection element 160, thus forming a conductive circuit of electrode assembly 120 - first current collector 151 - second current collector 152 - overcurrent protection element 160 - terminal post 140; and the overcurrent protection element 160 is configured to melt when the current passing through is greater than the rated threshold. For example, when a short circuit occurs in the single cell 100, a large current will be generated. At this time, the overcurrent protection element 160 melts to quickly cut off the conductive circuit of the single cell 100 and prevent the single cell 100 from thermal runaway.

[0057] The single cell 100 can be a rechargeable battery, which refers to a single cell that can be recharged after discharge to activate the active materials and continue to be used. For example, the single cell 100 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, or nickel-cadmium battery, but is not limited to these.

[0058] The single cell 100 can be a prismatic cell, a pouch cell, or a cell of other shapes. For example, in this application, the single cell 100 is a cylindrical cell.

[0059] The single-cell battery 100 also includes an electrolyte and other functional components. The electrolyte can be a conventional electrolyte or a special electrolyte with additives. The electrolyte is used to wet the electrode assembly 120. The electrode assembly 120 is the component in the single-cell battery 100 where the electrochemical reaction occurs, and there can be one or more electrode assemblies. The electrode assembly 120 is mainly formed by winding or stacking a positive electrode, a separator, and a negative electrode. The portions of the positive and negative electrode with active material constitute the main body of the electrode assembly 120, while the portions without active material constitute the tabs. During the charging and discharging process of the single-cell battery 100, the positive and negative active materials react with the electrolyte. The tabs are electrically connected to the terminals 140 through the current collector 150 to form a current loop, enabling the single-cell battery 100 to function normally.

[0060] The housing 110 may be made of a strong material such as metal, but is not limited to this. For example, the housing 110 may be made of aluminum profile or steel, but is not limited to this.

[0061] The end cap 130 can be integrally formed with the housing 110, meaning the end cap 130 can be the outer wall of the housing 110. The end cap 130 can also be fixedly connected to the housing 110, for example, by welding or other processes, to one end of the housing 110 in the Z-axis direction. This application does not impose specific limitations and can be configured according to actual circumstances. For example, in this application, the end cap 130 and the housing 110 are separately disposed, and the end cap 130 and the housing 110 are fixedly welded together.

[0062] In this application, the positive electrode, the separator, and the negative electrode are wound around the winding needle to form an electrode assembly 120. After the winding is completed, the winding needle is removed to form a central through hole 121 in the electrode assembly 120.

[0063] The current collector 150 can be a positive current collector or a negative current collector. This application does not make specific limitations and can be set according to the actual situation.

[0064] The current collector 150 can be made of various materials. For example, the current collector 150 can be made of copper, iron, aluminum, steel or aluminum alloy, but is not limited to these.

[0065] The first current collector 151 and the second current collector 152 can be integrally formed, meaning they are a single, integrated structure. Alternatively, they can be separate components, but fixedly connected. For example, the second current collector 152 is fixedly connected to the first current collector 151 via welding or other processes. This application does not impose specific limitations and can be configured according to actual circumstances. For example, in this application, the first current collector 151 and the second current collector 152 are integrally die-cast.

[0066] The overcurrent protection element 160 can be made of copper or aluminum, but is not limited to these materials.

[0067] Understandably, this application connects the current collector 150 and the terminal post 140 with an overcurrent protection element 160 to ensure that when an external short circuit occurs in the single cell 100, the overcurrent protection element 160 can melt first to cut off the conduction circuit of the single cell 100, thus preventing the single cell 100 from thermally running away due to excessive current caused by an external short circuit and the rapid accumulation of heat inside the casing 110. This improves the safety performance of the single cell 100. At the same time, this application sets the second current collector 152 of the current collector 150 in the central through hole 121 of the electrode assembly 120, and sets at least a portion of the overcurrent protection element 160 in the receiving groove 1524 of the second current collector 152. This makes full use of the redundant space inside the single cell 100 to install the overcurrent protection element 160, reduces the space occupied by the overcurrent protection element 160, increases the space occupancy rate of the electrode assembly 120 in the single cell 100, and increases the volumetric energy density of the single cell 100.

[0068] In some embodiments, refer to Figures 3 to 5 The overcurrent protection element 160 includes: a fuse 161, a first electrical connection 162, and a second electrical connection 163. The fuse 161, the first electrical connection 162, and the second electrical connection 163 are all disposed in the receiving groove 1524, and the fuse 161 is configured to melt when the current passing through is greater than the rated threshold.

[0069] The first electrical connection part 162 is connected to the side of the fuse part 161 near the pole post 140, and the first electrical connection part 162 is electrically connected to the pole post 140.

[0070] The second electrical connection 163 is connected to the side of the fuse 161 away from the electrode post 140, and the second electrical connection 163 is electrically connected to the second current collector 152. The electrode assembly 120, the first current collector 151, the second current collector 152, the second electrical connection 163, the fuse 161, the first electrical connection 162, and the electrode post 140 constitute a conductive circuit of electrode assembly 120-first current collector 151-second current collector 152-second electrical connection 163-fuse 161-first electrical connection 162-electrode post 140.

[0071] The fusible link 161, the first electrical connection 162, and the second electrical connection 163 can be integrally formed, meaning they form a single, integrated structure. Alternatively, the fusible link 161, the first electrical connection 162, and the second electrical connection 163 can be separately configured and fixedly connected in pairs. For example, the fusible link 161 is fixedly connected to the first electrical connection 162 and the second electrical connection 163 through welding or other processes. This application does not impose specific limitations and can be configured according to actual circumstances. For example, in this application, the fusible link 161, the first electrical connection 162, and the second electrical connection 163 are integrally die-cast.

[0072] Understandably, this application provides a fuse 161 on the overcurrent protection element 160 to ensure that when an external short circuit occurs in the single cell 100, the fuse 161 will melt first to cut off the conduction circuit of the single cell 100, thereby preventing the single cell 100 from thermally running away due to excessive current caused by the external short circuit, which would lead to a short-term accumulation of heat in the casing 110. This improves the safety performance of the single cell 100.

[0073] In some embodiments, refer to Figure 4 The dimension of the fuse portion 161 in the radial X direction is smaller than the dimension of the first electrical connection portion 162 in the radial X direction, and the dimension of the fuse portion 161 in the radial X direction is smaller than the dimension of the second electrical connection portion 163 in the radial X direction.

[0074] Specifically, refer to Figure 4The dimension of the fuse portion 161 in the radial X direction is L1 mm, the dimension of the first electrical connection portion 162 in the radial X direction is L2 mm, and the dimension of the second electrical connection portion 163 in the radial X direction is L3 mm, satisfying: L1 < L2, L1 < L3. That is, the dimension L1 mm of the fuse portion 161 in the radial X direction is smaller than the dimension L2 mm of the first electrical connection portion 162 in the radial X direction, and the dimension L1 mm of the fuse portion 161 in the radial X direction is smaller than the dimension L3 mm of the second electrical connection portion 163 in the radial X direction. This is so that when the current of the single battery 100 is too large due to an external short circuit, the fuse portion 161 can melt first to cut off the conduction circuit of the single battery 100, thereby avoiding the problem of heat accumulation in the casing 110 in a short time due to the excessive current caused by the external short circuit, which could lead to thermal runaway of the single battery 100, and improving the safety performance of the single battery 100.

[0075] The dimension L1 mm of the fuse part 161 in the radial X direction can be obtained by disassembling the actual single cell 100 and measuring the dimension of the fuse part 161 in the radial X direction on the overcurrent protection element 160 multiple times using a measuring tool and calculating the average value. The measuring tool can be any one of a ruler, vernier caliper, or other dimensional measuring instruments, but is not limited to this.

[0076] The dimension L2 mm of the first electrical connection portion 162 in the radial X direction can be obtained by disassembling the actual single cell 100 and measuring the dimension of the first electrical connection portion 162 in the radial X direction on the overcurrent protection element 160 multiple times using a measuring tool and calculating the average value. The measuring tool can be any one of a ruler, vernier caliper, or other dimensional measuring instruments, but is not limited to this.

[0077] The dimension L3 mm of the second electrical connection 163 in the radial X direction can be obtained by disassembling the actual single cell 100 and measuring the dimension of the second electrical connection 163 in the radial X direction on the overcurrent protection element 160 multiple times using a measuring tool and calculating the average value. The measuring tool can be any one of a ruler, vernier caliper, or other dimensional measuring instruments, but is not limited to this.

[0078] In some embodiments, refer to Figures 3 to 5 The overcurrent protection element 160 also includes a third electrical connection part 164, which is connected to the side of the first electrical connection part 162 near the pole post 140. A positioning groove 141 is provided on the side of the pole post 140 near the third electrical connection part 164, and the third electrical connection part 164 is embedded in the positioning groove 141. The third electrical connection part 164 is electrically connected to the first electrical connection part 162 on one side of the Z-axis, and electrically connected to the pole post 140 on the other side of the Z-axis.

[0079] The third electrical connection portion 164 is embedded in the positioning groove 141 to form a positioning structure. The overcurrent protection element 160 is positioned by the cooperation between the third electrical connection portion 164 and the positioning groove 141, preventing the overcurrent protection element 160 from moving arbitrarily and ensuring the overall stability of the single cell 100. At the same time, the first electrical connection portion 162 is electrically connected to the terminal post 140 through the third electrical connection portion 164 to form a conductive circuit of electrode assembly 120-first current collector 151-second current collector 152-second electrical connection portion 163-fuse portion 161-first electrical connection portion 162-third electrical connection portion 164-terminal post 140.

[0080] In some embodiments, refer to Figure 4 The dimension of the third electrical connection portion 164 in the radial X direction is larger than the dimension of the receiving groove 1524 in the radial X direction. Specifically, refer to Figure 4 The third electrical connection portion 164 has a radial dimension of L4 mm in the X direction, and the receiving groove 1524 has a radial dimension of L5 mm in the X direction, satisfying L4 > L5. That is, the radial dimension L4 mm of the third electrical connection portion 164 is greater than the radial dimension L5 mm of the receiving groove 1524, thus forming a limiting structure between the third electrical connection portion 164 and the first current collector 151. This facilitates the assembly of the overcurrent protection element 160 and the assembly connection between the overcurrent protection element 160 and the terminal post 140, improving the overall assembly efficiency of the single cell 100. It should be noted that the limiting structure can be formed simply by the third electrical connection portion 164 having a radial dimension at least partially larger than the receiving groove 1524.

[0081] The dimension L4 mm of the third electrical connection 164 in the radial X direction can be obtained by disassembling the actual single cell 100 and measuring the dimension of the third electrical connection 164 in the radial X direction on the overcurrent protection element 160 multiple times using a measuring tool and calculating the average value. The measuring tool can be any one of a ruler, vernier caliper, or other dimensional measuring instruments, but is not limited to this.

[0082] The dimension L5 mm of the receiving groove 1524 in the radial X direction can be obtained by disassembling the actual single cell 100 and measuring the distance in the radial X direction of the groove wall of the receiving groove 1524 on the current collector element 150 multiple times using a measuring tool and calculating the average value. The measuring tool can be any one of the following, but is not limited to: a ruler, vernier caliper, or other dimensional measuring instruments.

[0083] In some embodiments, refer to Figures 3 to 5The single cell 100 further includes: a first insulating member 171 and a second insulating member 172, at least a portion of the first insulating member 171 is disposed between the third electrical connection portion 164 and the first current collector portion 151, and at least a portion of the first insulating member 171 is disposed between the terminal post 140 and the first current collector portion 151; the second insulating member 172 covers the fuse portion 161, and the second insulating member 172 covers the first electrical connection portion 162. Specifically, the second insulating member 172 covers the fuse portion 161, and the second insulating member 172 covers the first electrical connection portion 162. This means that at any position of the axial height X, a cross section perpendicular to the axial direction X is made. On the cross section, the second insulating member 172 covers the outer periphery of the fuse portion 161, and the second insulating member 172 covers the outer periphery of the first electrical connection portion 162. This prevents the fuse portion 161 and the first electrical connection portion 162 from contacting the second current collector 152, so that the second current collector 152 can be electrically connected to the terminal 140 in the order of the second electrical connection portion 163, the fuse portion 161, the first electrical connection portion 162, and the third electrical connection portion 164.

[0084] Specifically, a portion of the first insulating member 171 is disposed between the third electrical connection portion 164 and the first current collector portion 151, and another portion of the first insulating member 171 is disposed between the terminal post 140 and the first current collector portion 151, so as to insulate and separate the third electrical connection portion 164 from the first current collector portion 151, and to insulate and separate the terminal post 140 from the first current collector portion 151, thereby preventing the third electrical connection portion 164 from contacting the first current collector portion 151 and preventing the terminal post 140 from contacting the first current collector portion 151 and causing a short circuit, ensuring the normal use of the single cell 100, and at the same time ensuring the safety performance of the single cell 100.

[0085] The second insulating member 172 covers the outer surface of the fuse portion 161, the first electrical connection portion 162, and part of the second electrical connection portion 163 to support and protect the fuse portion 161, preventing the fuse portion 161 from deforming and breaking when the single cell 100 is subjected to force, thus ensuring the normal use of the single cell 100. At the same time, the second insulating member 172 is used to insulate between the fuse portion 161 and the second current collector 152, and between the first electrical connection portion 162 and the second current collector 152, so as to ensure that all the current inside the single cell 100 flows through the overcurrent protection element 160, thereby ensuring that when an external short circuit occurs in the single cell 100, the overcurrent protection element 160 cuts off the conduction circuit of the single cell 100.

[0086] The first insulating member 171 and the second insulating member 172 can be of various types. For example, the first insulating member 171 and the second insulating member 172 can both be rubber, silicone or plastic, but are not limited to these.

[0087] In some embodiments, refer to Figures 4 to 5The second current collector 152 includes: a rigid part 1521, which protrudes from the side of the first current collector 151 away from the pole post 140; an elastic part 1522, which is connected to the side of the rigid part 1521 away from the first current collector 151, and the elastic part 1522 is provided along a broken line or arc on a cross section passing through the axial direction Z; and a bottom support part 1523, which is connected to the side of the elastic part 1522 away from the first current collector 151, and the bottom support part 1523 is electrically connected to the second electrical connection part 163; the rigid part 1521, the elastic part 1522 and the bottom support part 1523 together form a receiving groove 1524.

[0088] Specifically, the rigid portion 1521 extends along the axial direction Z and protrudes from the side of the first current collector 151 away from the terminal post 140; the elastic portion 1522 is connected to the side of the rigid portion 1521 away from the first current collector 151, and the elastic portion 1522 is configured to absorb the assembly tolerance of the single cell 100 in the axial direction Z; the bottom support portion 1523 is connected to the side of the elastic portion 1522 away from the first current collector 151, and the bottom support portion 1523 is electrically connected to the second electrical connection portion 163; the rigid portion 1521, the elastic portion 1522 and the bottom support portion 1523 together form a receiving groove 1524.

[0089] The rigid part 1521, the elastic part 1522, and the base support part 1523 can be integrally formed, meaning they form a single structure. Alternatively, they can be separately arranged and fixedly connected in pairs. For example, the elastic part 1522 is fixedly connected to the rigid part 1521 and the base support part 1523 through welding or other processes. This application does not impose specific limitations and can be configured according to actual circumstances. For example, in this application, the rigid part 1521, the elastic part 1522, and the base support part 1523 are integrally die-cast.

[0090] The elastic part 1522 can be either pleated or arc-shaped, but is not limited to these.

[0091] Understandably, additional assembly tolerances need to be reserved during the manufacturing and assembly of the single cell 100 to ensure efficient assembly of components. This application addresses this by providing a deformable elastic portion 1522 on the current collector element 150. When the single cell 100 is assembled, the current collector element 150 will bear external forces applied by other components. At this time, the elastic portion 1522 deforms along the Z-axis to eliminate the assembly tolerances reserved during the manufacturing and assembly of the single cell 100, ensuring the overall structural stability of the single cell 100. Simultaneously, since the elastic portion 1522 is located in the central through-hole 121 of the electrode assembly 120, the redundant space inside the single cell 100 is fully utilized to install the elastic portion 1522, reducing the space occupied by the elastic portion 1522, increasing the space utilization rate of the electrode assembly 120 in the single cell 100, and improving the volumetric energy density of the single cell 100.

[0092] In some embodiments, refer to Figure 5 The first insulating member 171 has a first outer wall 1711 away from the first current collector 151, and the bottom support 1523 has a second outer wall 15231 close to the elastic part 1522; when the second current collector 152 is not under force, the total dimension of the fuse part 161, the first electrical connection part 162 and the second electrical connection part 163 in the axial Z direction is greater than the distance between the first outer wall 1711 and the second outer wall 15231 in the axial Z direction.

[0093] Specifically, refer to Figure 5 When the second current collector 152 is not under stress, the total dimension of the fuse part 161, the first electrical connection part 162 and the second electrical connection part 163 in the axial Z direction is H1 mm, and the distance between the first outer wall 1711 and the second outer wall 15231 in the axial Z direction is H2 mm, satisfying: H1 > H2, that is, the total dimension H1 mm of the fuse part 161, the first electrical connection part 162 and the second electrical connection part 163 in the axial Z direction is greater than the distance H2 mm between the first outer wall 1711 and the second outer wall 15231 in the axial Z direction, so as to ensure that additional assembly tolerances are reserved in the manufacturing and assembly process of the single cell 100, so as to ensure the efficient assembly of the components in the single cell 100.

[0094] The total dimension H1 mm of the fuse part 161, the first electrical connection part 162, and the second electrical connection part 163 in the Z-axis direction can be obtained by disassembling the actual single cell 100 and measuring the distances between the sidewalls of the first electrical connection part 162 and the second electrical connection part 163 on the Z-axis direction away from the fuse part 161 multiple times using a measuring tool, and then calculating the average value. The measuring tool can be any one of a ruler, vernier caliper, or other dimensional measuring instruments, but is not limited to these.

[0095] The distance H2 mm between the first outer wall 1711 and the second outer wall 15231 in the axial direction Z can be obtained by disassembling the actual single cell 100 and measuring the distance between the first outer wall 1711 of the first insulating part 171 and the second outer wall 15231 of the base part 1523 multiple times using a measuring tool, and then calculating the average value. The measuring tool can be any one of a ruler, vernier caliper, or other dimensional measuring instruments, but is not limited to this.

[0096] The difference between the total dimension H1 mm of the fuse part 161, the first electrical connection part 162 and the second electrical connection part 163 in the axial Z direction and the distance H2 mm between the first outer wall 1711 and the second outer wall 15231 in the axial Z direction is the maximum value of the assembly tolerance.

[0097] When H1 mm and H2 mm satisfy the above parameter relationship, the structural dimensions of the fuse part 161, the first electrical connection part 162, the second electrical connection part 163, the first insulating member 171, the rigid part 1521 and the elastic part 1522 can be freely combined and designed.

[0098] In one embodiment, when the second current collector 152 is subjected to force and the elastic part 1522 is fully straightened, the dimension of the fully straightened elastic part 1522 in the axial Z direction is greater than the difference between the total dimension H1 mm of the fuse part 161, the first electrical connection part 162 and the second electrical connection part 163 in the axial Z direction and the distance H2 mm between the first outer wall 1711 and the second outer wall 15231 in the axial Z direction.

[0099] In some embodiments, refer to Figure 3 The single-cell battery 100 further includes a third insulating member 173, at least a portion of which is disposed between the end cap 130 and the terminal post 140, and at least a portion of which is disposed between the end cap 130 and the first current collector 151. The portion of the third insulating member 173 disposed between the end cap 130 and the terminal post 140 insulates the end cap 130 from contact with the terminal post 140, preventing a short circuit in the single-cell battery 100; and the other portion of the third insulating member 173 disposed between the end cap 130 and the first current collector 151 insulates the end cap 130 from contact with the first current collector 151, preventing a short circuit in the single-cell battery 100.

[0100] The third insulating element 173 can be of various types. For example, the third insulating element 173 can be rubber, silicone or plastic, but is not limited to these.

[0101] On the other hand, in the embodiments of this application, this application also provides a battery pack, including: a housing; and a single battery cell 100 as described in any of the above embodiments, the single battery cell 100 being disposed in the housing.

[0102] The battery pack can be a three-tiered system consisting of individual cells 100, battery modules, and a battery pack. This means the individual cells 100 are first grouped into battery modules, and then the battery modules are placed inside a housing to form the battery pack. Alternatively, it can be a two-tiered system consisting of individual cells 100 and a battery pack, where the individual cells 100 are directly housed within a housing to form the battery pack. No specific limitations are imposed in this application; the design can be tailored to the specific circumstances, as long as it does not affect the effectiveness of this application.

[0103] The above steps are provided only to help understand the method, structure, and core ideas of this application. Those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A single-cell battery having an axial orientation, characterized in that, include: The housing has an opening at one end in the axial direction; An electrode assembly is disposed within the housing, and the electrode assembly has a central through hole; End cap, connected to the housing and sealing the opening; The pole post is inserted into the end cap; A current collector element is disposed within the housing and includes: a first current collector and a second current collector. The first current collector is disposed between the end cap and the electrode assembly and is electrically connected to the electrode assembly. The second current collector is connected to the side of the first current collector away from the electrode post and is inserted into the central through hole. as well as An overcurrent protection element is provided, wherein a receiving groove is provided on the side of the second current collector facing the pole post, at least a portion of the overcurrent protection element is inserted into the receiving groove, one end of the overcurrent protection element is electrically connected to the second current collector, and the other end of the overcurrent protection element is electrically connected to the pole post.

2. The single-cell battery as described in claim 1, characterized in that, The overcurrent protection element includes: a fuse, a first electrical connection, and a second electrical connection, wherein the fuse, the first electrical connection, and the second electrical connection are all disposed within the receiving groove; The first electrical connection portion is connected to the side of the fuse portion near the electrode post, and the first electrical connection portion is electrically connected to the electrode post; The second electrical connection is connected to the side of the fuse portion away from the pole, and the second electrical connection is electrically connected to the second current collector.

3. The single-cell battery as described in claim 2, characterized in that, The individual cell also has a radial direction perpendicular to the axis; The radial dimension of the fused portion is smaller than the radial dimension of the first electrical connection portion, and the radial dimension of the fused portion is smaller than the radial dimension of the second electrical connection portion.

4. The single-cell battery as described in claim 2, characterized in that, The overcurrent protection element further includes a third electrical connection portion, which is connected to the side of the first electrical connection portion near the pole post; The electrode post has a positioning groove on the side near the third electrical connection part, the third electrical connection part is embedded in the positioning groove, and the third electrical connection part is electrically connected to the first electrical connection part on one side of the axial direction, and the third electrical connection part is electrically connected to the electrode post on the other side of the axial direction.

5. The single-cell battery as described in claim 4, characterized in that, The individual cell also has a radial direction perpendicular to the axis; The radial dimension of the third electrical connection is larger than the radial dimension of the receiving groove.

6. The single-cell battery as described in claim 4, characterized in that, Also includes: The first insulating member and the second insulating member, at least a portion of the first insulating member is disposed between the third electrical connection portion and the first current collector portion, and at least a portion of the first insulating member is disposed between the pole and the first current collector portion; The second insulating element covers the fused portion and also covers the first electrical connection portion.

7. The single-cell battery as described in claim 6, characterized in that, The second current collector includes a rigid portion, which protrudes from the first current collector on the side away from the pole post; An elastic portion is connected to the rigid portion on the side away from the first current collector. On a cross-section passing through the axial direction, the elastic portion is arranged along a broken line or an arc. The base portion is connected to the side of the elastic portion away from the first current collecting portion, and the base portion is electrically connected to the second electrical connection portion; The rigid part, the elastic part, and the bottom support part together form the receiving groove.

8. The single-cell battery as described in claim 7, characterized in that, The first insulating member has a first outer wall away from the first current collecting portion, and the base portion has a second outer wall close to the elastic portion; When the second current collector is not under force, the total axial dimension of the fuse, the first electrical connection and the second electrical connection is greater than the axial distance between the first outer wall and the second outer wall.

9. The single-cell battery as described in claim 1, characterized in that, Also includes: The third insulating element is at least partially disposed between the end cap and the pole post, and at least partially disposed between the end cap and the first current collector.

10. A battery pack, characterized in that, include: Box; as well as The single-cell battery as described in any one of claims 1 to 9, wherein the single-cell battery is disposed within the housing.

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