Battery cell and battery

Abstract

The utility model provides a battery cell and a battery, and relates to the technical field of batteries. The battery cell comprises a shell, a cover plate, a roll core and a current collection part, wherein the cover plate and the shell are covered to define a containing cavity; the roll core and the current collection part are arranged at an interval and are positioned in the accommodating cavity; the current collecting piece is provided with a first surface facing the roll core, the first surface comprises a connecting area and a non-connecting area, the non-connecting area and the roll core are arranged at an interval, the connecting area is connected with the tab of the roll core, and the current collecting piece is provided with a first through hole communicated with the non-connecting area. According to the invention, through the arrangement, a space for electrolyte to flow is formed between the current collection piece and the end face of the winding core, so that the electrolyte can flow into the space between the non-connection area and the winding core from the first through hole. Therefore, the mobility of the electrolyte between the current collection piece and the roll core can be improved, the electrolyte can infiltrate the pole piece from the top of the roll core, and finally, the infiltration efficiency can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to battery cells and batteries. Background Art

[0002] In related technologies, the current collector is a key component of a battery cell. It connects to the poles and the tabs of the winding core, transferring current collected by the tabs to the poles, or vice versa. The winding core primarily consists of a positive electrode sheet, a separator, and a negative electrode sheet stacked and wound in sequence. The tabs are located at the end faces of the winding core and connected to the pole sheets. The current collector is located on the side of the tab facing away from the pole sheet and is also connected to the tab.

[0003] After the cell is assembled, it needs to be filled with electrolyte. The electrolyte is first injected into the cell through the injection hole in the cell's top cover. It then flows through the current collector and the central hole in the winding core to the bottom of the cell's cavity. Next, the electrolyte begins to penetrate the pores of the electrode and, through capillary action, flows up the electrode, completing the electrolyte saturation of the entire electrode.

[0004] Because in the related art, the electrode can only be wetted from bottom to top, resulting in poor electrode wetting efficiency. Utility Model Content

[0005] The embodiments of the present application provide a battery cell and a battery that can improve the problem of poor electrode wetting efficiency.

[0006] In the first aspect, an embodiment of the present application provides a battery cell, which includes a shell, a cover plate, a winding core and a collector, the cover plate is covered with the shell to define a accommodating cavity; the winding core is arranged in the accommodating cavity; the collector is arranged in the accommodating cavity and is located at one end of the winding core; the collector has a first surface facing the winding core, the first surface includes a connection area and a non-connection area, the non-connection area is spaced apart from the winding core, the connection area is connected to the pole ear of the winding core, and the collector is provided with a first through hole, which is connected to the non-connection area.

[0007] In one embodiment, the non-connection area is provided with a clearance groove, and the groove bottom and / or groove wall of the clearance groove are provided with a first through hole.

[0008] In one embodiment, a connection between the groove wall of the clearance groove and the groove bottom of the clearance groove has a corner, and the first through hole is arranged at a distance from the corner.

[0009] In one embodiment, the minimum distance between the hole wall and the corner of the first through hole is d1, the thickness of the collector is d, and the following condition is satisfied: 0.2d≤d1.

[0010] In one embodiment, the current collector further has a second surface, which is disposed opposite to the first surface. The second surface is provided with protrusions, and the clearance grooves are correspondingly disposed with the protrusions, and the clearance grooves extend into the corresponding protrusions.

[0011] In one embodiment, along the axis of the current collector, the distance between the bottom of the clearance groove and the first surface is h, and the thickness of the current collector is d, which satisfies: 0.5d≤h≤2d.

[0012] In one embodiment, the clearance groove is an annular groove, and the annular groove is extended along the circumference of the collector.

[0013] In one embodiment, the clearance groove includes a plurality of first sub-grooves, the plurality of first sub-grooves are spaced apart along the circumferential direction of the current collector, and the first sub-grooves extend along the radial direction of the current collector.

[0014] In one embodiment, the give way groove includes a plurality of inner sub-grooves and a plurality of outer sub-grooves, the plurality of inner sub-grooves are arranged on the side of the collector close to the axis of the collector, the plurality of outer sub-grooves are arranged on the side of the collector close to the circumference of the collector, and the plurality of inner sub-grooves and the plurality of outer sub-grooves are respectively arranged at intervals along the circumference of the collector.

[0015] In one embodiment, the plurality of inner sub-grooves and the plurality of outer sub-grooves are distributed alternately along the circumference of the current collector.

[0016] In one embodiment, the minimum distance between the hole wall of the first through hole and the periphery of the current collector is d2, the thickness of the current collector is d, and the following condition is satisfied: 2d≤d2.

[0017] In one embodiment, a central hole is provided on the current collector, the minimum distance between the hole wall of the first through hole and the hole wall of the central hole is d3, the thickness of the current collector is d, and the following condition is satisfied: 2d≤d3.

[0018] In a second aspect, an embodiment of the present application provides a battery comprising the aforementioned battery cell.

[0019] Beneficial effects of the embodiments of the present application:

[0020] In the embodiments of the present application, by spacing the non-connected area from the winding core and providing a first through-hole communicating with the non-connected area, a space for electrolyte flow is created between the current collector and the end face of the winding core. This allows the electrolyte to flow through the first through-hole into the space between the non-connected area and the winding core. This improves the fluidity of the electrolyte between the current collector and the winding core, allowing the electrolyte to penetrate the electrode from the top of the winding core, ultimately improving the wetting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 is a schematic structural diagram of a battery cell provided in an embodiment of the present application;

[0023] Figure 2 is a schematic structural diagram of a current collector provided in an embodiment of the present application;

[0024] Figure 3 yes Figure 2 Cross-sectional view of AA;

[0025] Figure 4 yes Figure 3 Enlarged view of point B in the middle;

[0026] Figure 5 This is a schematic structural diagram of another current collector provided in an embodiment of the present application;

[0027] Figure 6 yes Figure 5 Cross-sectional view of CC;

[0028] Figure 7 This is a schematic structural diagram of another current collector provided in an embodiment of the present application;

[0029] Figure 8 yes Figure 7 Cross-sectional view of the middle DD;

[0030] Figure 9 It is a schematic structural diagram of a battery provided in an embodiment of the present application.

[0031] Description of reference numerals:

[0032] 011-current collector; 111-first surface; 112-connection area; 113-non-connection area;

[0033] 1131-yield slot; 11311-first sub-slot; 11312-outer sub-slot; 11313-inner sub-slot;

[0034] 1132 - first through hole; 114 - second surface; 115 - protrusion;

[0035] 012-center hole;

[0036] 002-battery core; 021-housing; 022-cover plate; 023-winding core; 231-ear; 024-accommodation cavity;

[0037] 003-battery; 031-box; 032-box cover. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0039] Furthermore, it should be understood that the specific embodiments described herein are intended only to illustrate and explain the present application and are not intended to limit the present application. In this application, unless otherwise indicated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the directions of the drawings in the accompanying drawings; whereas "inner" and "outer" refer to the outline of the device.

[0040] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the specified features. In the description of this application, "plurality" means two or more, unless otherwise specifically specified.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0042] The terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0043] In the description of the embodiments of this application, words such as "example" or "for example" are used to indicate an example, illustration, or description. Any embodiment or design described as "for example" or "for example" in the embodiments of this application is not to be construed as being preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to clearly present relative concepts.

[0044] To facilitate understanding of the solution of the present application, the spline curves and arrows used in the drawings are explained here: the components indicated by the spline curves without arrows are solid components, that is, components with solid structures; the components indicated by the spline curves with arrows are virtual components, that is, components without solid structures.

[0045] See also Figures 1 to 3 , Figure 1 This is a schematic diagram of the structure of the battery cell 002 provided in an embodiment of the present application. Figure 2 is a schematic structural diagram of the current collector 011 provided in an embodiment of the present application, Figure 3 yes Figure 2 Cross-sectional view of AA in FIG. An embodiment of the present application provides a battery cell 002, which includes a shell 021, a cover plate 022, a winding core 023 and a collector 011. The cover plate 022 covers the shell 021 to define a accommodating cavity 024. The winding core 023 is arranged in the accommodating cavity 024. The collector 011 is arranged in the accommodating cavity 024 and is located at one end of the winding core 023. The collector 011 has a first surface 111 facing the winding core 023. The first surface 111 includes a connection area 112 and a non-connection area 113. The non-connection area 113 is spaced apart from the winding core 023, the connection area 112 is connected to the pole ear 231 of the winding core 023, and the collector 011 is provided with a first through hole 1132, which is connected to the non-connection area 113.

[0046] Specifically, the connection method between the connection area 112 and the tab 231 of the winding core 023 can be, but is not limited to, threaded connection, welding, clamping, plugging, and riveting.

[0047] The winding core 023 includes a positive electrode sheet, a separator, and a negative electrode sheet stacked and wound in sequence, with the separator positioned between the positive and negative electrode sheets. The positive and negative electrode sheets include a coated area coated with active material and an uncoated area uncoated with active material. The tabs may be integrally formed as at least a portion of the uncoated area. In other embodiments, the tabs may be separately welded to the electrode sheets.

[0048] It is understood that battery cell 002 should include two current collectors 011, one for positive and one for negative. The positive and negative collectors can be located at the same end of winding core 023, or at opposite ends of winding core 023. When the two current collectors 011 are located at opposite ends of winding core 023, the axis of the current collectors 011 is collinear with the axis of the battery cell 002. Furthermore, a central hole 012 is provided at the center of the current collector 011, which is opposite the central hole of winding core 023.

[0049] Among them, the positive collector is connected to the positive electrode column and the positive electrode ear of the winding core 023, one side of the negative electrode flow disc is connected to the negative electrode ear of the winding core 023, and the other side is connected to the shell 021 or the negative electrode column.

[0050] Optionally, the current collector 011 is a circular structure. The shape of the first through hole 1132 includes, but is not limited to, circular, elliptical, oval, fan-shaped, rectangular, and arc-shaped. The connection region 112 is where the current collector 011 connects to the tab 231, and the non-connection region 113 is where the current collector 011 is not connected to the tab 231.

[0051] In this embodiment, by spacing the non-connected area 113 from the winding core 023 and providing a first through-hole 1132 communicating with the non-connected area 113, space for electrolyte flow is created between the current collector 011 and the winding core 023. This allows the electrolyte to flow through the first through-hole 1132 between the non-connected area 113 and the winding core 023. This improves the fluidity of the electrolyte between the current collector 011 and the winding core 023, allowing the electrolyte to penetrate the electrode from the top of the winding core 023, ultimately improving the wetting efficiency.

[0052] See also Figure 3 In one embodiment, the non-connection region 113 is provided with a clearance groove 1131. The groove bottom and / or groove wall of the clearance groove 1131 are provided with a first through hole 1132. Each clearance groove 1131 is provided with at least one first through hole 1132.

[0053] Specifically, the first through hole 1132 is provided at the bottom of the give way groove 1131 , or the first through hole 1132 is provided at the wall of the give way groove 1131 , or the first through hole 1132 is provided at the bottom and the wall of the give way groove 1131 .

[0054] The clearance groove 1131 can be processed on the current collector 011 by cutting, or can be punched out on the current collector 011 by stamping.

[0055] In this embodiment, a space for electrolyte flow is formed between the non-connected area 113 and the winding core 023 by providing a clearance groove 1131, which not only improves the wetting efficiency but also makes the collector 011 simple in structure and easy to form.

[0056] See also Figure 4 , Figure 4 yes Figure 3 In one embodiment, the connection between the groove wall of the clearance groove 1131 and the groove bottom of the clearance groove 1131 has a corner, and the first through hole 1132 is spaced apart from the groove wall of the clearance groove 1131 .

[0057] It is understood that the corner between the wall and bottom of the clearance groove 1131 is a location where the surface geometry of the current collector 011 suddenly changes, which can cause high stress at the connection between the wall and bottom of the clearance groove 1131. When the stress is high, the current collector 011 is likely to deform at this connection.

[0058] Based on this, in this embodiment, by spacing the first through hole 1132 and the connection between the groove wall and the groove bottom of the giveway groove 1131, the influence of the setting of the first through hole 1132 on the strength of the connection can be reduced, thereby improving the deformation resistance of the connection and further improving the structural reliability of the collector 011.

[0059] See also Figure 4 In one embodiment, the minimum distance between the hole wall and the corner of the first through hole 1132 is d1, and the thickness of the collector 011 is d, which satisfies: 0.2d≤d1.

[0060] Furthermore, 0.2d≤d1≤1d.

[0061] The thickness of the current collector 011 refers to the thickness of a portion of the current collector 011 where the clearance groove 1131 is not provided, that is, the distance between the first surface 111 and the second surface 114 .

[0062] For example,

[0063] When d is 0.15mm, the minimum spacing d1 includes but is not limited to: 0.03mm, 0.1mm, 0.2mm, 0.25mm, 0.3mm, 0.45mm, 0.562mm, 0.6mm, 0.75mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.3mm, 0.15mm;

[0064] When d is 0.5mm, the minimum spacing d1 includes but is not limited to: 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.21mm, 0.225mm, 0.23mm, 0.24mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm;

[0065] When d is 0.8mm, the minimum spacing d1 includes but is not limited to: 0.16mm, 0.2mm, 0.24mm, 0.26mm, 0.3mm, 0.35mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.44mm, 0.48mm, 0.5mm, 0.6mm, and 0.8mm.

[0066] In this embodiment, through the above-mentioned limitation, the influence of the setting of the first through hole 1132 on the strength of the connection between the groove wall and the groove bottom of the give way groove 1131 can be further reduced, thereby improving the deformation resistance of the connection, so that the groove wall of the give way groove 1131 can support the groove bottom of the give way groove 1131, and then the structural reliability of the collector 011 can be improved.

[0067] See also Figure 3 In one embodiment, the current collector 011 further comprises a second surface 114. The second surface 114 is disposed opposite the first surface 111. A protrusion 115 is disposed on the second surface 114. Along the axis of the current collector 011, a clearance groove 1131 is disposed corresponding to the protrusion 115, and the clearance groove 1131 extends into the corresponding protrusion 115.

[0068] In this embodiment, through the above-mentioned setting, on the one hand, the clearance groove 1131 can have a sufficient depth to facilitate the flow of electrolyte; on the other hand, the thickness of the collector 011 can be made uniform, and only the clearance groove 1131 has a larger height dimension, thereby controlling the material usage of the collector 011 and further controlling the material cost of the collector 011.

[0069] See also Figure 4 , Figure 4 yes Figure 3 In one embodiment, along the axis of the current collector 011 , there is a distance h between the bottom of the clearance groove 1131 and the first surface 111 , and the thickness of the current collector 011 is d, satisfying the following: 0.5d≤h≤2d.

[0070] It can be understood that the spacing h between the bottom of the groove 1131 and the connecting area 112 includes but is not limited to 0.5d, 0.55d, 0.58d, 0.6d, 0.62d, 0.65d, 0.68d, 0.7d, 0.8d, 0.9d, 1d, 1.1d, 1.2d, 1.3d, 1.4d, 1.5d, 1.6d, 1.7d, 1.8d, 1.9, 1.92d, 1.95d, 1.96d, 1.98d, and 2d.

[0071] For example:

[0072] When the thickness d of the current collector 011 is 0.15 mm, h includes but is not limited to 0.075 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.16 mm, 0.175 mm, 0.19 mm, 0.2 mm, 0.22 mm, 0.23 mm, 0.245 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, 0.295 mm, and 0.3 mm;

[0073] When the thickness d of the current collector 011 is 0.5 mm, h includes but is not limited to 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, 0.295 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.66 mm, 0.7 mm, 0.72 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.88 mm, 0.9 mm, 0.953 mm, 0.97 mm, and 1 mm;

[0074] When the thickness d of the collector 011 is 0.8 mm, h includes but is not limited to 0.4 mm, 0.6 mm, 0.8 mm, 0.88 mm, 0.9 mm, 0.95 mm, 0.98 mm, 1 mm, 1.1 mm, 1.13 mm, 1.15 mm, 1.2 mm, 1.3 mm, 1.35 mm, 1.4 mm, 1.46 mm, 1.48 mm, 1.5 mm, 1.55 mm, and 1.6 mm.

[0075] In this embodiment, through the above-mentioned limitation, on the one hand, it is possible to avoid the spacing h between the bottom of the give way groove 1131 and the connection area 112 being too small, resulting in insufficient electrolyte flow cross-section, thereby ensuring the fluidity of the electrolyte and helping to improve the wetting efficiency of the electrode; on the other hand, it is possible to avoid the spacing h between the bottom of the give way groove 1131 and the connection area 112 being too large, resulting in the collector 011 occupying more space inside the battery cell 002, thereby ensuring the energy density of the battery cell 002.

[0076] See also Figure 2 and Figure 3In one embodiment, the clearance groove 1131 is an annular groove that extends along the circumference of the current collector 011 .

[0077] There may be one or more annular grooves. When there are multiple annular grooves, the multiple annular grooves are spaced apart from each other from the center of the current collector 011 outwards.

[0078] In this embodiment, by using an annular groove as the clearance groove 1131, the electrolyte can flow into the collector 011 and the end surface of the winding core more evenly, thereby making the electrode sheet more uniformly wetted, thereby improving the electrode sheet wetting efficiency.

[0079] See also Figure 5 and Figure 6 , Figure 5 This is a schematic structural diagram of another current collector 011 provided in an embodiment of the present application; Figure 6 yes Figure 5 In one embodiment, the clearance groove 1131 includes a plurality of first sub-grooves 11311. The plurality of first sub-grooves 11311 are arranged at intervals along the circumference of the current collector 011. The first sub-grooves 11311 extend radially along the current collector 011.

[0080] The first sub-groove 11311 may radially penetrate the groove wall close to the periphery of the collector 011, such as Figure 5 As shown, the electrolyte flowing between the outer periphery of the winding core and the shell 021 of the battery cell 002 can flow into the first sub-groove 11311 from one end of the first sub-groove 11311 close to the periphery of the collector 011.

[0081] In addition, the first sub-groove 11311 can also radially penetrate the groove wall on the side close to the center of the collector 011 to connect with the center hole 012, so that the electrolyte flowing into the center hole 012 can flow into the first sub-groove 11311 from the end of the first sub-groove 11311 close to the center hole 012.

[0082] Specifically, the clearance groove 1131 is a fan-shaped groove, and the size of the clearance groove 1131 in the circumferential direction of the current collector 011 gradually increases as it moves away from the center of the current collector 011 .

[0083] In this embodiment, the above arrangement allows the electrode to have more parts in contact with the electrolyte, thereby enabling simultaneous wetting of multiple parts of the electrode, thereby further improving the wetting efficiency of the electrode.

[0084] See also Figure 7 and Figure 8 , Figure 7 This is a structural diagram of another current collector 011 provided in an embodiment of the present application. Figure 8 yes Figure 7Cross-sectional view of DD in FIG. In one embodiment, the clearance groove 1131 includes multiple inner sub-grooves 11313 and multiple outer sub-grooves 11312. The multiple inner sub-grooves 11313 are disposed on a side of the current collector 011 close to the axis of the current collector 011. The multiple outer sub-grooves 11312 are disposed on a side of the current collector 011 close to the circumference of the current collector 011. The multiple inner sub-grooves 11313 and the multiple outer sub-grooves 11312 are spaced apart along the circumference of the current collector 011.

[0085] The outer sub-groove 11312 may radially penetrate the groove wall close to the periphery of the collector 011, such as Figure 8 As shown, the electrolyte flowing between the outer periphery of the winding core and the shell 021 of the battery cell 002 can flow into the outer sub-slot 11312 from one end of the outer sub-slot 11312 close to the periphery of the collector 011.

[0086] In addition, the inner sub-groove 11313 may radially penetrate the groove wall on the side close to the center of the collector 011, such as Figure 8 As shown, it is connected to the central hole 012 so that the electrolyte flowing into the central hole 012 can flow into the inner sub-tank 11313 from one end of the inner sub-tank 11313 close to the central hole 012.

[0087] Specifically, the inner sub-groove 11313 and the outer sub-groove 11312 are both fan-shaped grooves. As they move away from the center of the collector 011 , the sizes of the inner sub-groove 11313 and the outer sub-groove 11312 in the circumferential direction of the collector 011 gradually increase.

[0088] In this embodiment, the above arrangement allows the electrode to have more locations in contact with the electrolyte in the circumferential direction, thereby enabling simultaneous wetting of multiple locations of the electrode, thereby further improving the wetting efficiency of the electrode.

[0089] See also Figure 7 In one embodiment, along the circumference of the current collector 011 , a plurality of inner sub-grooves 11313 and a plurality of outer sub-grooves 11312 are alternately distributed.

[0090] In this embodiment, through the above-mentioned arrangement, the current collector 011 can have a sufficient width dimension between the inner sub-groove 11313 and the outer sub-groove 11312, thereby ensuring the strength of the current collector 011 and ensuring that the current collector 011 has a sufficient width for connection with the pole tab, thereby improving the operability and connection reliability of the current collector 011 and the pole tab.

[0091] See also Figure 2 In one embodiment, the minimum distance between the hole wall of the first through hole 1132 and the periphery of the collector 011 is d2, and the thickness of the collector 011 is d, which satisfies: 2d≤d2.

[0092] It can be understood that d2 includes but is not limited to 2d, 2.2d, 2.5d, 2.8d, 3d, 3.5d, 4d, 4.5d, and 5d.

[0093] For example,

[0094] When d is 0.15mm, d2 is not less than 0.3mm;

[0095] When d is 0.5mm, d2 is not less than 1mm;

[0096] When d is 0.8mm, d2 shall not be less than 1.6mm.

[0097] In this embodiment, the above-mentioned restrictions ensure sufficient spacing between the walls of the first through-holes 1132 and the periphery of the current collector 011, thereby ensuring a complete and robust connection structure at the outer ring of the current collector 011. This, in turn, increases the planar strength of the current collector 011, thereby improving the flatness of the connection region 112. Ultimately, the contact area between the connection region 112 and the tab layer of the winding core is increased, thereby enhancing the reliability and ease of connection between the current collector 011 and the tab.

[0098] See also Figure 2 In one embodiment, a central hole 012 is provided on the current collector 011, the minimum distance between the hole wall of the first through hole 1132 and the hole wall of the central hole 012 is d3, the thickness of the current collector 011 is d, and the following condition is satisfied: 2d≤d3.

[0099] It can be understood that d3 includes but is not limited to 2d, 2.2d, 2.5d, 2.8d, 3d, 3.5d, 4d, 4.5d, and 5d.

[0100] For example,

[0101] When d is 0.15mm, d3 is not less than 0.3mm;

[0102] When d is 0.5mm, d3 is not less than 1mm;

[0103] When d is 0.8mm, d3 shall not be less than 1.6mm.

[0104] In this embodiment, the above-mentioned restrictions ensure sufficient spacing between the walls of the first through-hole 1132 and the walls of the central hole 012, thereby ensuring a complete and robust connection structure for the inner ring of the current collector 011. This, in turn, increases the planar strength of the current collector 011, thereby improving the flatness of the connection region 112. Ultimately, the contact area between the connection region 112 and the tab layer of the winding core is increased, thereby enhancing the reliability and ease of connection between the current collector 011 and the tab.

[0105] See also Figure 9 Accordingly, an embodiment of the present application provides a battery 003 , which includes the aforementioned battery cell 002 .

[0106] It is understandable that the battery 003 may further include a box body 031 or a bottom plate, and the battery cell 002 is disposed in the box body 031 , or the battery cell 002 is mounted on the bottom plate.

[0107] In this embodiment, by using the aforementioned battery cell 002, a channel for electrolyte to flow between the current collector 011 and the end surface of the winding core is increased. Furthermore, based on the spacing between the non-connected region 113 and the winding core 023, a space for electrolyte flow is formed between the current collector 011 and the winding core 023. This allows the electrolyte to flow through the first through-hole 1132 between the non-connected region 113 and the winding core 023. This improves the wetting efficiency of the battery cell 002 and, ultimately, the manufacturing efficiency of the battery 003.

[0108] On the basis of the above embodiments, the various embodiments in this application are summarized to obtain the following embodiments:

[0109] An embodiment of the present application provides a battery cell 002, which includes a shell 021, a cover plate 022, a winding core 023, and a collector 011. The cover plate 022 covers the shell 021 to define a housing cavity 024. The winding core 023 is disposed in the housing cavity 024. The collector 011 is disposed in the housing cavity 024 and is located at one end of the winding core 023. Along the axis of the collector 011, the collector 011 has a first surface 111 facing the tab and a second surface 114 facing away from the tab. The first surface 111 includes a connection area 112 and a non-connection area 113. The non-connection area 113 is spaced apart from the winding core 023, and the connection area 112 is connected to the tab 231 of the winding core 023. The non-connection area 113 is provided with a clearance groove 1131. The bottom of the clearance groove 1131 is provided with a first through hole 1132. The axis of the collector 011 is collinear with the axis of the battery cell 002 to which the collector 011 is applied. A center hole 012 is provided at the center of the collector 011. The collector 011 is a circular structure. Along the axis of the collector 011, there is a spacing h between the bottom of the clearance groove 1131 and the connection area 112. The thickness of the collector 011 is d, satisfying: 0.5d≤h≤2d. The hole wall of the first through hole 1132 is spaced apart from the groove wall of the clearance groove 1131. The minimum spacing between the hole wall of the first through hole 1132 and the groove wall of the clearance groove 1131 is d1, satisfying: 0.2d≤d1. The second surface 114 is disposed opposite to the first surface 111. The second surface 114 is provided with a protrusion 115. Along the axis of the current collector 011 , the clearance groove 1131 is disposed opposite to the protrusion 115 , and the side of the clearance groove 1131 away from the first surface 111 is disposed in the protrusion 115 .

[0110] There are many implementations of the recess 1131. In this embodiment, the following structures are used as examples for illustration:

[0111] Structure 1: The clearance groove 1131 may include an annular groove, which is arranged to extend along the circumference of the collector 011. In this case, the first through hole 1132 is circular. Figure 2 shown.

[0112] Structure 2, the give way groove 1131 may include a plurality of first sub-grooves 11311. The plurality of first sub-grooves 11311 are arranged at intervals along the circumference of the collector 011. The first sub-grooves 11311 are extended radially along the collector 011. The first sub-grooves 11311 may radially penetrate the groove wall close to the periphery of the collector 011. The first sub-grooves 11311 may also radially penetrate the groove wall close to the center of the collector 011. At this time, the give way groove 1131 is a fan-shaped groove, and the size of the give way groove 1131 in the circumferential direction of the collector 011 increases successively as it moves away from the center of the collector 011. And the shape of the first through hole 1132 may be one or more of circular, elliptical, and arc-shaped, such as Figure 5 shown.

[0113] Structure 3: The clearance groove 1131 includes multiple inner sub-grooves 11313 and multiple outer sub-grooves 11312. The multiple inner sub-grooves 11313 are arranged on the side of the collector 011 close to the axis of the collector 011. The multiple outer sub-grooves 11312 are arranged on the side of the collector 011 close to the circumference of the collector 011. The multiple inner sub-grooves 11313 and the multiple outer sub-grooves 11312 are respectively arranged at intervals along the circumference of the collector 011. Along the circumference of the collector 011, the multiple inner sub-grooves 11313 and the multiple outer sub-grooves 11312 are staggered. The outer sub-grooves 11312 can radially penetrate the groove wall close to the periphery of the collector 011. The inner sub-grooves 11313 can radially penetrate the groove wall close to the center of the collector 011. The inner sub-groove 11313 and the outer sub-groove 11312 are both fan-shaped grooves. As they move away from the center of the collector 011, the sizes of the inner sub-groove 11313 and the outer sub-groove 11312 in the circumferential direction of the collector 011 increase successively. The shape of the first through hole 1132 can be one or more of circular, elliptical, and arc-shaped, such as Figure 7 shown.

[0114] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery cell, characterized in that: include: case; a cover plate, covering the shell to define a receiving cavity; a winding core, disposed in the accommodating cavity; A current collector is disposed in the accommodating cavity and located at one end of the winding core; In which, the collector has a first surface facing the winding core, the first surface includes a connection area and a non-connection area, the non-connection area is spaced apart from the winding core, the connection area is connected to the pole ear of the winding core, and the collector is provided with a first through hole, which is connected to the non-connection area.

2. The battery cell according to claim 1, characterized in that The non-connection area is provided with a clearance groove, and the groove bottom and / or groove wall of the clearance groove are provided with the first through hole.

3. The battery cell according to claim 2, characterized in that A corner is formed at a connection between the groove wall of the give way groove and the groove bottom of the give way groove, and the first through hole is spaced apart from the corner.

4. The battery cell according to claim 3, characterized in that The minimum distance between the hole wall of the first through hole and the corner is d1, and the thickness of the collector is d, which satisfies: 0.2d≤d1.

5. The battery cell according to any one of claims 2 to 4, characterized in that: The current collector also has a second surface, which is arranged opposite to the first surface. The second surface is provided with a protrusion, and the clearance groove is arranged corresponding to the protrusion, and the clearance groove extends into the corresponding protrusion.

6. The battery cell according to claim 5, characterized in that Along the axis of the current collector, the distance between the bottom of the groove of the clearance groove and the first surface is h, and the thickness of the current collector is d, which satisfies: 0.5d≤h≤2d.

7. The battery cell according to any one of claims 2 to 4, characterized in that: The relief groove is an annular groove, and the annular groove is extended along the circumference of the collector.

8. The battery cell according to any one of claims 2 to 4, characterized in that: The clearance groove includes a plurality of first sub-grooves, the plurality of first sub-grooves are arranged at intervals along the circumferential direction of the current collector, and the first sub-grooves are extended along the radial direction of the current collector.

9. The battery cell according to any one of claims 2 to 4, characterized in that: The give way groove includes a plurality of inner sub-grooves and a plurality of outer sub-grooves, the plurality of inner sub-grooves are arranged on the side of the collector close to the axis of the collector, and the plurality of outer sub-grooves are arranged on the side of the collector close to the circumference of the collector, and the plurality of inner sub-grooves and the plurality of outer sub-grooves are respectively arranged at intervals along the circumference of the collector.

10. The battery cell according to claim 9, characterized in that: Along the circumference of the current collector, the plurality of inner sub-grooves and the plurality of outer sub-grooves are distributed alternately.

11. The battery cell according to any one of claims 1 to 4, characterized in that: The minimum distance between the hole wall of the first through hole and the periphery of the collector is d2, the thickness of the collector is d, and the following relationship is satisfied: 2d≤d2.

12. The battery cell according to any one of claims 1 to 4, characterized in that: The current collector is provided with a central hole, the minimum distance between the hole wall of the first through hole and the hole wall of the central hole is d3, the thickness of the current collector is d, and the following condition is satisfied: 2d≤d3.

13. A battery, characterized in that: Comprising the battery cell according to any one of claims 1 to 12.

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