Pole, cover plate assembly and high-capacity single battery

Abstract

The utility model provides a pole, a cover plate assembly and a high-capacity single battery, and relates to the technical field of batteries. The pole comprises a body and a bottom plate; the bottom plate is connected with the body, a tab mounting space is defined by the bottom plate and the body, a first opening is defined by the body and / or the bottom plate, and the first opening is configured to communicate the tab mounting space with an inner cavity of the single battery; and the edges of the surfaces, which are configured to be in contact with the tabs, of the bottom plate and the body are chamfered. According to the scheme, the tab can penetrate through the first opening and is located in the tab mounting space. Therefore, the tab and the pole share the height space, so that the space occupied by the original tab is used for arranging the electrode assembly, and the energy density of the single battery is improved; and the tab can be wrapped in the tab mounting space, so that the tail end of the tab is isolated from the electrode assembly by the part of the wall surface of the formed tab mounting space on the pole, and the tab can be effectively prevented from being inversely inserted into the electrode assembly.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of batteries, in particular to a pole, a cover plate assembly and a large-capacity single battery. BACKGROUND

[0002] With the transformation of energy to green and low carbon, power batteries, as a key technology to achieve the goal of low carbon, have developed rapidly. With the rapid development of power batteries, higher energy demand and reliability demand for lithium batteries have been put forward in all-scene use environment.

[0003] In the related art, a single battery includes a shell, an electrode assembly arranged in the shell, and a pole arranged on the shell. There is a height difference between the electrode assembly and the pole. The space forming the height difference mainly has two functions. One is to provide space for arranging the tab and the conductive connecting piece connecting the tab and the pole, and the other is to increase the distance between the tab and the electrode assembly to reduce the risk of the tab being inserted into the electrode assembly upside down. Due to the existence of this part of space, the internal space utilization rate of the single battery is low, thereby resulting in a low energy density of the single battery. If part of the space is directly omitted, it is easy to cause the tab to be inserted into the electrode assembly upside down, thereby causing the single battery to fail. Therefore, how to improve the energy density of the single battery while avoiding the tab being inserted into the electrode assembly upside down is a problem that needs to be solved in the battery field. UTILITY MODEL CONTENT

[0004] Embodiments of the application provide a pole, a cover plate assembly and a large-capacity single battery, which can improve the energy density of the single battery while avoiding the tab being inserted into the electrode assembly upside down.

[0005] In a first aspect, embodiments of the application provide a pole applied to a single battery, the pole comprising a body and a bottom plate; the bottom plate is connected with the body, and an ear mounting space is defined between the bottom plate and the body; the body and / or the bottom plate define a first opening configured to communicate the ear mounting space with an inner cavity of the single battery; edges of surfaces of the bottom plate and the body configured to contact the tab are chamfered.

[0006] In some embodiments, the body has a first surface configured to face the inner cavity of the single battery, and the first surface is provided with a groove; the bottom plate is arranged across a slot opening of the groove, the bottom plate covers part of the slot opening of the groove, and the bottom plate and an inner wall of the groove define the ear mounting space, and the other part of the slot opening is the first opening.

[0007] In an embodiment, first step grooves are arranged on two opposite groove walls of the groove, the first step grooves are arranged adjacent to the slot opening of the groove, and two ends of the bottom plate are respectively engaged with the two first step grooves.

[0008] In an embodiment, a surface of the bottom plate away from a groove bottom of the groove is flush with the first surface.

[0009] In one embodiment, along the axial direction of the pole, the bottom plate has a thickness dimension d1, and the depth dimension of the groove is d4, which satisfies: 30% d4 ≤ d1 ≤ 70% d4.

[0010] In one embodiment, along the extension direction of the first step groove, an extension portion is protruded from the portion where the bottom plate overlaps the first step groove, and the extension portion overlaps the first step groove.

[0011] In one embodiment, a reinforcing rib is provided in the angle formed between the extension portion and the bottom plate, and two sides of the reinforcing rib are respectively connected to the extension portion and the bottom plate.

[0012] In one embodiment, the main body has a second surface configured to face away from the inner cavity of the single cell, and a second step groove is provided on the periphery of the second surface; a third step groove is provided on the outer peripheral surface of the main body, and along the axial direction of the pole, the second step groove and the third step groove are sequentially provided away from the second surface, and the portion on the outer peripheral surface of the main body located on the side of the third step groove close to the second surface is configured to cooperate with the pressure ring of the single cell.

[0013] In one embodiment, along the axial direction of the pole, the second step groove has a depth dimension d2, and the pole has a height dimension H, which satisfies: 2%H≤d2≤10%H.

[0014] In a second aspect, an embodiment of the present application provides a cover plate assembly, which includes a cover plate and the aforementioned pole; the cover plate is provided with a mounting hole; and the body is inserted into the mounting hole.

[0015] In one embodiment, the cover assembly further comprises a pressure ring, an upper plastic part, a lower plastic part and a sealing ring; the pressure ring is sleeved on the side of the body away from the inner cavity of the single cell; the upper plastic part is arranged between the pressure ring and the cover; the lower plastic part is arranged on the side of the cover away from the upper plastic part; the sealing ring seals the cover and the body

[0016] In one embodiment, an outward turning edge cooperating with the cover plate is provided on the side of the outer peripheral surface of the main body away from the pressure ring, and a sinking platform is provided on the side of the cover plate away from the pressure ring, and the mounting hole passes through the bottom wall of the sinking platform; the inner peripheral surface and outer peripheral surface of the sealing ring are respectively sealed with the outer peripheral surface of the main body and the peripheral wall of the sinking platform, and the two end faces of the sealing ring are respectively sealed with the bottom wall of the sinking platform and the outward turning edge.

[0017] In one embodiment, the outer radius of the sealing ring is r1, and the inner radius is r2, satisfying: r1-r2≥3mm.

[0018] In one embodiment, a receiving groove is provided on a side of the lower plastic component facing away from the cover plate. The receiving groove is configured to receive a portion of a tab of a single battery cell. The receiving groove is provided adjacent to the first opening, and the opening of the receiving groove faces the same direction as the first opening.

[0019] In one embodiment, the body has a second surface configured to face away from the inner cavity of the single battery cell. The pressure ring is welded to the body, and a weld mark formed by the welding does not protrude from the second surface.

[0020] On the third aspect, an embodiment of the present application provides a large-capacity single cell battery, which includes a shell, an electrode assembly, a tab and the aforementioned cover assembly; the shell has an inner cavity; the electrode assembly is arranged in the inner cavity; one end of the tab is connected to the electrode assembly, and the other end passes through the first opening and is located in the tab installation space, and the tab is connected to the base plate and / or the body.

[0021] Beneficial effects of the embodiments of the present application:

[0022] In the embodiments of the present application, by defining a tab installation space and a first opening connecting it to the inner cavity of a single cell, the tab can pass through the first opening and be located within the tab installation space. This allows the tab to share the same height space with the electrode post, allowing the space originally occupied by the tab to be used to install the electrode assembly, thereby improving the energy density of the single cell. Furthermore, the tab installation space can enclose the tab, allowing the wall of the electrode post forming the tab installation space to isolate the end of the tab from the electrode assembly, thereby effectively preventing the tab from being inserted upside down into the electrode assembly, thereby improving the reliability of the single cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1 is a schematic structural diagram of a pole provided in an embodiment of the present application;

[0025] Figure 2 is a side view of a first surface of a pole provided by an embodiment of the present application;

[0026] Figure 3 It is along Figure 2 Cross-sectional view of AA;

[0027] Figure 4 Schematic diagram of the matching of a pole and a tab provided in an embodiment of the present application;

[0028] Figure 5 This is a schematic diagram of the structure of the main body provided by the embodiment of the present application;

[0029] Figure 6 It is along Figure 2Cross-sectional view of the middle BB;

[0030] Figure 7 yes Figure 6 Enlarged view of point C in the middle;

[0031] Figure 8 is a side view of a first surface of another pole provided by an embodiment of the present application;

[0032] Figure 9 is a side view of a first surface of yet another pole provided in an embodiment of the present application;

[0033] Figure 10 is a cross-sectional view of another pole provided in an embodiment of the present application;

[0034] Figure 11 is an exploded view of a cover plate assembly provided in an embodiment of the present application;

[0035] Figure 12 is a cross-sectional view of a cover plate assembly provided in an embodiment of the present application;

[0036] Figure 13 yes Figure 12 Enlarged view of point D in the middle;

[0037] Figure 14 This is a partial structural diagram of the lower plastic part provided in an embodiment of the present application;

[0038] Figure 15 It is a schematic structural diagram of a large-capacity single cell battery provided in an embodiment of the present invention.

[0039] Description of reference numerals:

[0040] 001-pole;

[0041] 011-body; 111-first surface; 112-groove; 113-first opening; 114-first step groove; 115-outward edge; 116-first connecting member; 117-second connecting member; 118-second step groove; 119-second surface; 119a-third step groove;

[0042] 012-base plate; 121-extension portion; 122-reinforcement rib;

[0043] 013- Tab installation space;

[0044] 002-cover assembly; 021-cover; 211-mounting hole; 212-sink; 022-pressing ring; 023-upper plastic part; 024-lower plastic part; 241-accommodation groove; 242-through hole; 025-sealing ring;

[0045] 003-large-capacity single cell battery; 031-shell; 311-inner cavity; 032-electrode assembly; 033-ear. DETAILED DESCRIPTION

[0046] 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.

[0047] In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not intended to limit the present application. In the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0048] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0049] The terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0050] 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.

[0051] See also Figure 1-Figure 3 , Figure 1 is a schematic structural diagram of the pole 001 provided in an embodiment of the present application, Figure 2is a side view of the first surface 111 of the pole post 001 according to an embodiment of the present application, Figure 3 is a sectional view along Figure 2 A-A of FIG. 1, an embodiment of the present application provides a pole post 001 applied to a single battery.

[0052] The pole post 001 comprises a body 011 and a bottom plate 012. The bottom plate 012 is connected with the body 011. The pole post 001 comprises a tab mounting space 013 defined between the bottom plate 012 and the body 011. The body 011 and / or the bottom plate 012 define a first opening 113. The first opening 113 is configured to communicate the tab mounting space 013 with an inner cavity of the single battery. The edges of the surfaces of the bottom plate 012 and the body 011 configured to contact the tab are chamfered.

[0053] Specifically, the body 011 defines the first opening 113, or the bottom plate 012 defines the first opening 113, or the body 011 and the bottom plate 012 jointly define the first opening 113.

[0054] Specifically, the end of the tab penetrates through the first opening 113 and is located in the tab mounting space 013, and the tab is electrically connected with the bottom plate 012 or the body 011, or the tab is electrically connected with the bottom plate 012 and the body 011 at the same time, so as to realize the overcurrent between the tab and the pole post 001, as shown in Figure 4 Figure 4 is a schematic view of the pole post 001 cooperating with the tab according to an embodiment of the present application.

[0055] Since the tab is made of foil material and has a small thickness, the edges of the surfaces of the bottom plate 012 and the body 011 configured to contact the tab are chamfered, and optionally, the edges of the surfaces of the bottom plate 012 and the body 011 configured to contact the tab are rounded, so as to prevent the tab from being cut.

[0056] It can be understood that the part where the bottom plate 012 is connected with the body 011 is the overcurrent part between the bottom plate 012 and the body 011. Specifically, the bottom plate 012 is welded with the body 011.

[0057] In the embodiment, by defining the tab mounting space 013 and the first opening 113 communicating the tab mounting space 013 with the inner cavity of the single battery, the tab can penetrate through the first opening 113 and be located in the tab mounting space 013. In this way, on the one hand, the tab shares the height space with the pole post 001, so as to use the space originally occupied by the tab to set the electrode assembly, thereby improving the energy density of the single battery; on the other hand, the tab can be covered in the tab mounting space 013, so that the part of the wall surface of the pole post 001 forming the tab mounting space 013 isolates the end of the tab from the electrode assembly, thereby effectively avoiding the tab being inserted into the electrode assembly in reverse, so as to improve the reliability of the single battery. ​

[0058] Furthermore, in this embodiment, by directly connecting the terminal post 001 to the tab, the conductive connecting sheet connecting the tab and the terminal post 001 is eliminated. This not only reduces the number of components in the battery cell, thereby controlling related costs and improving assembly efficiency, but also allows the space previously used for the conductive connecting sheet to be used for the electrode assembly, thereby increasing the energy density of the battery cell.

[0059] See also Figure 1-Figure 3 In some embodiments, the body 011 has a first surface 111 facing the inner cavity of the single cell. A groove 112 is provided on the first surface 111. A bottom plate 012 is disposed across the opening of the groove 112. The bottom plate 012 covers a portion of the opening of the groove 112 and, together with the inner wall of the groove 112, defines a tab mounting space 013. The remaining portion of the opening is a first opening 113.

[0060] When the base plate 012 is positioned in the middle of the notch of the groove 112, the notch on either side of the base plate 012 defines a first opening 113. This allows one portion of the tab to enter the tab installation space 013 through one first opening 113, while another portion of the tab enters the tab installation space 013 through the other first opening 113. This improves the symmetry of the tab arrangement and thus enhances the uniformity of force applied to the individual cells.

[0061] It can be understood that the periphery of the notch of the groove 112 not covered by the bottom plate 012 and the adjacent edge of the bottom plate 012 enclose a first opening 113. The space between the bottom plate 012 and the bottom of the groove 112 is the tab installation space 013, which is configured to mate with the tab of a single battery cell.

[0062] It can be understood that the bottom plate 012 is arranged parallel to the notch of the groove 112 to cover a portion of the notch of the groove 112 .

[0063] Specifically, the minimum distance D between the bottom plate 012 and the bottom of the groove 112 satisfies the following: 0.5 mm ≤ D ≤ 5 mm. The distance between the bottom plate 012 and the bottom of the groove 112 can be adaptively designed based on different battery models and the corresponding number of positive and negative tabs.

[0064] In this embodiment, by providing the groove 112 and the bottom plate 012 that partially covers the notch of the groove 112 and defines the first opening 113, the tab can pass through the gap between the bottom plate 012 and the wall of the groove 112 and be located between the bottom of the groove 112 and the bottom plate 012. This, on the one hand, makes the terminal 001 simple in structure and easy to form; on the other hand, the bottom plate 012 can isolate the end of the tab from the electrode assembly, effectively preventing the tab from being inserted upside down into the electrode assembly, thereby improving the reliability of the single cell.

[0065] See also Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the structure of the main body 011 provided in an embodiment of the present application. Figure 6 It is along Figure 2 In one embodiment, first step grooves 114 are provided on two opposite groove walls of the groove 112. The first step grooves 114 are provided adjacent to the notch of the groove 112. The two ends of the bottom plate 012 are respectively overlapped with the two first step grooves 114.

[0066] In this embodiment, by setting the first step groove 114 to overlap the end of the base plate 012, on the one hand, it can play a positioning role for the base plate 012 when the pole 001 is assembled, thereby improving the assembly efficiency of the pole 001 and facilitating the smooth welding of the base plate 012 and the body 011; on the other hand, it can provide more contact areas between the body 011 and the base plate 012, thereby improving the reliability of the overcurrent between the body 011 and the base plate 012.

[0067] See also Figure 3 or Figure 5 In one embodiment, the surface of the bottom plate 012 facing away from the bottom of the groove 112 is flush with the first surface 111. This allows the surface of the electrode post 001 facing the inner cavity of the single cell to be flat, thereby reducing the difficulty of arranging the electrode assembly and controlling the height of the electrode post 001 to increase the volume of the electrode assembly, thereby improving the energy density of the single cell.

[0068] Please refer to the figure Figure 3 and Figure 7 , Figure 7 yes Figure 6 Enlarged view of point C. In one embodiment, along the axial direction of the pole 001, the bottom plate 012 has a thickness dimension d1, and the depth dimension of the groove is d4, which satisfies: 30% d4 ≤ d1 ≤ 70% d4.

[0069] It will be understood that the base plate 012 has a thickness dimension d1 including but not limited to 30% d4, 32% d4, 33% d4, 34% d4, 35% d4, 38% d4, 40% d4, 43% d4, 48% d4, 50% d4, 52% d4, 54% d4, 55% d4, 56% d4, 58% d4, 60% d4, 62% d4, 64% d4, 65% d4, 67% d4, and 70% d4.

[0070] It can be understood that the thickness dimension d1 of the bottom plate 012 also corresponds to the depth dimension of the first step groove 114 .

[0071] In this embodiment, by limiting the thickness of the base plate 012, on the one hand, it can ensure that the tab installation space 013 has a sufficient height dimension to facilitate the arrangement of the tab; on the other hand, it can not only ensure that the base plate 012 has appropriate strength to meet the isolation requirements between the tab and the electrode assembly, but also ensure that the base plate 012 and the main body 011 have an appropriate contact surface area to meet the flow requirements between the base plate 012 and the main body 011.

[0072] See also Figure 8 , Figure 8 This is a side view of the first surface 111 of another pole 001 provided in an embodiment of the present application. In one embodiment, an extension portion 121 is provided protruding from the portion where the base plate 012 overlaps the first step groove 114 along the extension direction of the first step groove 114. The extension portion 121 overlaps the first step groove 114.

[0073] In this embodiment, by providing the extension portion 121, on the one hand, the area of ​​the contact surface between the base plate 012 and the body 011 can be increased to improve the flow capacity between the base plate 012 and the body 011; on the other hand, the area of ​​the welding surface between the base plate 012 and the body 011 can be increased to improve the welding strength between the base plate 012 and the body 011, thereby improving the structural stability of the pole 001.

[0074] See also Figure 9 , Figure 9 This is a side view of the first surface 111 of another pole 001 provided in an embodiment of the present application. In one embodiment, a reinforcing rib 122 is provided in the angle formed between the extension 121 and the base plate 012. The two sides of the reinforcing rib 122 are connected to the extension 121 and the base plate 012, respectively.

[0075] In this embodiment, the provision of the reinforcing rib 122 can enhance the strength of the connection portion between the extension portion 121 and the body 011 , preventing the extension portion 121 from being damaged due to impact during assembly, thereby improving the assembly efficiency of the pole 001 .

[0076] See also Figure 3 In one embodiment, an outward-turned edge 115 is provided on a side of the outer peripheral surface of the body 011 close to the first surface 111 .

[0077] It can be understood that the outward edge 115 is a structure formed by the outer peripheral surface of the body 011 extending along the radial direction of the pole 001.

[0078] In this embodiment, by providing the outward-turned edge 115 , the fitting area between the pole 001 and the top cover of the single cell can be increased, thereby improving the position stability of the pole 001 when installed on the single cell.

[0079] See also Figure 10 , Figure 10 This is a cross-sectional view of another electrode 001 provided in an embodiment of the present application. In one embodiment, along the axial direction of electrode 001, body 011 includes a first connector 116 and a second connector 117. One side of first connector 116 is connected to one side of second connector 117. The other side of first connector 116 is provided with a groove 112. Base plate 012 is connected to first connector 116. The material of first connector 116 and base plate 012 is consistent with the material of the battery cell's tabs to which they are electrically connected. Second connector 117 is made of aluminum.

[0080] Specifically, when the negative electrode tab is made of copper, the base plate 012 and the first connector 116 connected to the negative electrode tab are also made of copper.

[0081] In particular, since the groove 112 is provided on the second connecting member 117, and the second connecting member 117 is connected to the first connecting member 116 near the portion opposite to the bottom of the groove 112, in order to improve the connection strength between the first connecting member 116 and the second connecting member 117, optionally, along the axial direction of the pole 001, the thickness of the portion where the first connecting member 116 and the second connecting member 117 are connected is d3, and satisfies: d3 ≥ 0.5 mm, to ensure the connection strength between the first connecting member 116 and the second connecting member 117, which are made of different materials.

[0082] In this embodiment, through the above-mentioned arrangement, the material of the first connecting member 116 and the material of the bottom plate 012 can be consistent with the material of the pole ear connected thereto, thereby improving the conductivity therebetween, and the second connecting member 117 is made of aluminum material, which can reduce the weight of the pole 001, thereby controlling the weight of the single cell.

[0083] See also Figure 7 In one embodiment, the body 011 has a second surface 119 that is configured to face away from the inner cavity of the single cell. A second stepped groove 118 is provided around the periphery of the second surface 119. A third stepped groove 119a is provided on the outer circumference of the body 011. Along the axial direction of the terminal 001, the second stepped groove 118 and the third stepped groove 119a are arranged, respectively, away from the second surface 119. The portion of the outer circumference of the body 011 located on the side of the third stepped groove 119a near the second surface 119 is configured to mate with the pressure ring of the single cell.

[0084] It is understood that the body 011 facing away from the inner cavity of the single cell needs to be fitted with a pressure ring 022 to secure the terminal 001 to the cell cover 021 in the axial direction in conjunction with the outward-turned edge 115. The pressure ring 022 needs to be welded to the body 011. The weld mark formed by the welding has a certain height dimension.

[0085] Based on this, in this embodiment, by providing a second stepped groove 118, the weld mark formed by welding the body 011 and the pressure ring 022 can be located within the second stepped groove 118, thereby improving the flatness of the second surface 119 where the terminal 001 and the pressure ring 022 are welded, and further improving the flatness of the terminal 001 when it is attached to the connecting bar. This improves the reliability of the welding between the terminal 001 and the connecting bar and effectively avoids cold welds.

[0086] See also Figure 7 In one embodiment, along the axial direction of the pole 001 , the second step groove 118 has a depth dimension d2 , and the pole has a height dimension H, satisfying: 2% H ≤ d2 ≤ 10% H.

[0087] It can be understood that the second step groove 118 has a depth dimension d2 including but not limited to 2%H, 2.5%H, 3%H, 3.2%H, 3.8%H, 4%H, 4.2%H, 4.5%H, 5%H, 6%H, 6.2%H, 7%H, 7.4%H, 7.9%H, 8%H, 8.2%H, 8.5%H, 9%H, 9.2%H, 9.7%H, and 10%H.

[0088] In this embodiment, by limiting the depth dimension of the second step groove 118 , it can meet the requirement of accommodating the weld mark to improve the flatness of the second surface 119 , while avoiding the influence of its depth dimension on the strength of the pole 001 due to being too large.

[0089] See also Figure 11 and Figure 12 , Figure 11 is an exploded view of the cover assembly 002 provided in an embodiment of the present application. Figure 12 002 is a cross-sectional view of a cover plate assembly 002 provided in an embodiment of the present application. Accordingly, an embodiment of the present application further provides a cover plate assembly 002. The cover plate assembly 002 includes a cover plate 021.

[0090] As will be understood, cover plate assembly 002 also includes a pressure ring 022, an upper plastic component 023, a lower plastic component 024, and a sealing ring 025. Pressure ring 022 is sleeved onto the side of body 011 facing away from the inner cavity of the single cell. Upper plastic component 023 is positioned between pressure ring 022 and cover plate 021. Lower plastic component 024 is positioned on the side of cover plate 021 facing away from upper plastic component 023. Sealing ring 025 seals the gap between cover plate 021 and body 011.

[0091] The distance between the side of the pressure ring 022 facing away from the cover plate 021 and the cover plate 021 is not greater than the distance between the bottom wall of the first step groove 114 and the cover plate 021. Optionally, the side of the pressure ring 022 facing away from the cover plate 021 is coplanar with the bottom wall of the first step groove 114.

[0092] In addition, the cover plate assembly 002 may include two poles 001, such as Figure 11 As shown, one of them is the positive electrode column 001, which is connected to the positive electrode ear, and the other is the negative electrode column 001, which is connected to the negative electrode ear.

[0093] In this embodiment, by using the aforementioned terminal post 001, the tab can pass through the first opening 113 and be located within the tab installation space 013. This allows the tab and the terminal post 001 to share a common height space, allowing the space originally occupied by the tab to be used to install the electrode assembly, thereby improving the energy density of the single cell. Furthermore, the tab can be enclosed within the tab installation space 013, so that the wall of the terminal post 001 forming the tab installation space 013 isolates the end of the tab from the electrode assembly, thereby effectively preventing the tab from being inserted upside down into the electrode assembly, thereby improving the reliability of the single cell.

[0094] See also Figure 13 , Figure 13 yes Figure 12 Enlarged view of point D in the middle. In one embodiment, the outer circumference of the body 011, facing away from the pressure ring 022, is provided with an outward-turned edge 115 that engages with the cover plate 021. A recessed platform 212 is provided on the side of the cover plate 021 facing the inner cavity of the single cell. The mounting hole 211 extends through the bottom wall of the recessed platform 212. The inner and outer circumferential surfaces of the sealing ring 025 are respectively sealed against the outer circumferential surface of the body 011 and the circumferential wall of the recessed platform 212. The two end faces of the sealing ring 025 are respectively sealed against the bottom wall of the recessed platform 212 and the outward-turned edge 115.

[0095] The outer peripheral surface of the outward-turned edge 115 abuts against the inner peripheral surface of the sealing ring 025 along the radial direction of the pole 001 .

[0096] In this embodiment, the inner and outer circumferential surfaces and both end surfaces of the sealing ring 025 serve as sealing surfaces, thereby improving the sealing between the cover plate 021 and the pole 001 and thus improving the reliability of the single battery.

[0097] See also Figure 13 In one embodiment, the outer radius of the sealing ring 025 is r1, and the inner radius is r2, satisfying: r1-r2≥3mm.

[0098] It can be understood that the difference between the outer radius r1 and the inner radius r2 of the sealing ring 025 includes but is not limited to 3mm, 3.2mm, 3.3m, 3.2mm, 3.4m, 3.5m, 3.6m, 3.7m, 3.8m, 3.9m, 4mm, 5mm, and 6mm.

[0099] Furthermore, 3mm≤r1-r2≤10mm.

[0100] It can be understood that in the related art, the difference between the outer radius r1 and the inner radius r2 of the sealing ring 025 is 2 mm. In the embodiment, after the sealing ring 025 is assembled, the bottom plate 012 needs to be welded with the body 011. The welding will affect the sealing performance of the sealing ring 025. Based on this, the radial dimension of the sealing ring 025 is lengthened, so that the area of the sealing surface in the radial direction is increased, thereby ensuring the sealing performance between the cover plate 021 and the pole 001 after the bottom plate 012 is welded with the body 011.

[0101] Please refer to Figure 14 , Figure 14 is a partial structure schematic diagram of the lower plastic part 024 provided by the embodiment of the present application. In an embodiment, the side of the lower plastic part 024 away from the cover plate 021 is provided with a receiving groove 241. The receiving groove 241 is configured to accommodate part of the tab of the single battery. The receiving groove 241 is arranged adjacent to the first opening 113, and the opening of the receiving groove 241 is oriented in the same direction as the first opening 113.

[0102] It can be understood that the lower plastic part 024 is also provided with a through hole 242 for the tab to pass through. The tab is located between the bottom plate 012 and the groove bottom of the groove 112 after passing through the through hole 242 and the first opening 113 in turn.

[0103] The receiving groove 241 is arranged adjacent to the first opening 113 and located on the side of the first opening 113 away from the bottom plate 012. The first opening 113 has two, and the two first openings 113 are respectively located on both sides of the bottom plate 012. Correspondingly, the receiving groove 241 has two, and is respectively located on the side of the two first openings 113 away from the bottom plate 012.

[0104] In the embodiment, by arranging the receiving groove 241, the lower plastic part 024 not only plays a role of insulating and protecting the electrode assembly and the cover plate 021, but also can accommodate the bent tab through the receiving groove 241, thereby effectively avoiding the tab from being inserted into the electrode assembly in reverse.

[0105] In an embodiment, the height of the lower plastic part 024 is H0, which satisfies: H0≥2 mm.

[0106] It can be understood that in the related art, in order to make the lower plastic part 024 have enough space to accommodate the tab and the conductive connecting piece, the minimum height of the lower plastic part 024 is 5 mm. In the embodiment, the tab shares the height space with the pole 001, and the tab is blocked by the bottom plate 012 to avoid being inserted into the electrode assembly in reverse. In this way, in the embodiment, the height dimension of the lower plastic part 024 can be reduced to 2 mm. Therefore, the embodiment can increase the size of the electrode assembly to improve the energy density of the single battery, and can also reduce the material cost of the lower plastic part 024 to control the cost of the single battery.

[0107] See also Figure 12 and Figure 13 In one embodiment, the body 011 has a second surface 119 that is configured to face away from the inner cavity of the single cell. The pressure ring 022 is welded to the body 011 , and the weld mark formed therebetween does not protrude from the second surface 119 .

[0108] It can be understood that the weld mark formed by welding the pressure ring 022 and the body 011 has a certain height dimension.

[0109] Based on this, in this embodiment, by limiting the weld mark formed by the welding of pressure ring 022 and body 011 to not protrude from second surface 119, the flatness of second surface 119 where terminal 001 is welded to pressure ring 022 can be improved, thereby improving the flatness of the connection between terminal 001 and the connecting bar. This improves the reliability of the weld between terminal 001 and the connecting bar, effectively preventing cold welds.

[0110] Specifically, a second step groove 118 is provided on the periphery of the second surface 119 , so that the weld mark formed by welding between the body 011 and the pressure ring 022 can be located in the second step groove 118 .

[0111] See also Figure 15 , Figure 15 is a schematic structural diagram of a large-capacity single cell battery 003 provided in an embodiment of the present application. Accordingly, an embodiment of the present application also provides a large-capacity single cell battery 003. The large-capacity single cell battery 003 includes a housing 031, an electrode assembly 032, a tab 033, and the aforementioned cover assembly 002. Housing 031 has an inner cavity 311. Electrode assembly 032 is disposed in inner cavity 311. One end of tab 033 is connected to electrode assembly 032, and the other end passes through first opening 113 and is located in tab mounting space 013. Tab 033 is connected to base plate 012 and / or body 011.

[0112] Specifically, the tab 033 is connected to the bottom plate 012 , or the tab 033 is connected to the body 011 , or the tab 033 is connected to both the bottom plate 012 and the body 011 .

[0113] It can be understood that the electrode assembly 032 includes at least a positive electrode sheet, a separator, and a negative electrode sheet that are stacked.

[0114] In addition, the tab 033 can be a positive tab or a negative tab.

[0115] In this embodiment, by using the aforementioned cover plate 021 assembly, the tab 033 can be positioned between the bottom of the groove 112 and the bottom plate 012 after the first opening 113. This allows the tab 033 to share the same height space with the terminal post 001, allowing the space originally occupied by the tab 033 to be used to accommodate the electrode assembly 032, thereby improving the energy density of the large-capacity single battery cell 003. Furthermore, the tab can be enclosed within the tab mounting space 013, so that the wall surface of the terminal post 001 formed with the tab mounting space 013 isolates the end of the tab 033 from the electrode assembly 032, effectively preventing the tab 033 from being inserted upside down into the electrode assembly 032, thereby improving the reliability of the large-capacity single battery cell 003.

[0116] 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 pole, applied to a single battery, characterized in that: The pole comprises: ontology; a bottom plate connected to the body, wherein a tab installation space is defined between the bottom plate and the body, and the body and / or the bottom plate define a first opening, wherein the first opening is configured to connect the tab installation space with the inner cavity of the single battery; The edges of the bottom plate and the surface of the body configured to contact the tabs are chamfered.

2. The pole according to claim 1, characterized in that The body has a first surface configured to face the inner cavity of the single battery, and the first surface is provided with a groove; The bottom plate is arranged across the notch of the groove and covers a portion of the notch. The bottom plate and the inner wall of the groove define the tab installation space, and the other portion of the notch is the first opening.

3. The pole according to claim 2, characterized in that Two opposite groove walls of the groove are provided with first step grooves, the first step grooves are provided adjacent to the groove opening, and the two ends of the bottom plate are respectively overlapped with the two first step grooves.

4. The pole according to claim 3, characterized in that A surface of the bottom plate facing away from the groove bottom of the groove is flush with the first surface.

5. The pole according to claim 4, characterized in that: Along the axial direction of the pole, the bottom plate has a thickness dimension d1, and the depth dimension of the groove is d4, which satisfies: 30% d4≤ d1≤ 70% d4.

6. The pole according to any one of claims 3 to 5, characterized in that: Along the extension direction of the first step groove, an extension portion is protruded from the portion where the bottom plate overlaps the first step groove, and the extension portion overlaps the first step groove.

7. The pole according to claim 6, characterized in that A reinforcing rib is provided in the angle formed between the extension portion and the bottom plate, and two sides of the reinforcing rib are respectively connected to the extension portion and the bottom plate.

8. The pole according to any one of claims 1 to 5, characterized in that: The body has a second surface configured to face away from the inner cavity of the single battery, and a second step groove is provided on the periphery of the second surface; A third step groove is provided on the outer circumferential surface of the body. Along the axial direction of the pole, the second step groove and the third step groove are arranged in sequence away from the second surface. The portion of the outer circumferential surface of the body located on the side of the third step groove close to the second surface is configured to cooperate with the pressure ring of the single battery.

9. The pole according to claim 8, characterized in that Along the axial direction of the pole, the second step groove has a depth dimension d2, and the pole has a height dimension H, which satisfies: 2%H≤d2≤10%H.

10. A cover plate assembly, characterized in that: include: A cover plate is provided with a mounting hole; The pole according to any one of claims 1 to 9, wherein the body is inserted into the mounting hole.

11. The cover plate assembly according to claim 10, wherein: The cover plate assembly further comprises: A pressure ring is sleeved on a side of the body away from the inner cavity of the single battery; an upper plastic part, disposed between the pressure ring and the cover plate; a lower plastic part, disposed on a side of the cover plate facing away from the upper plastic part; A sealing ring is used to seal between the cover plate and the body.

12. The cover plate assembly according to claim 11, wherein: The outer circumference of the main body is provided with an outward turning edge on the side away from the pressure ring and cooperates with the cover plate to stop, and the cover plate is provided with a sinking platform on the side away from the pressure ring, and the mounting hole passes through the bottom wall of the sinking platform; the inner circumference and outer circumference of the sealing ring are respectively sealed with the outer circumference of the main body and the circumferential wall of the sinking platform, and the two end faces of the sealing ring are respectively sealed with the bottom wall of the sinking platform and the outward turning edge.

13. The cover plate assembly according to claim 12, wherein: The outer radius of the sealing ring is r1, and the inner radius is r2, satisfying: r1-r2≥3mm.

14. The cover plate assembly according to claim 11, wherein: A receiving groove is provided on a side of the lower plastic part away from the cover plate. The receiving groove is configured to receive a portion of a tab of the single battery. The receiving groove is provided adjacent to the first opening, and the opening of the receiving groove and the first opening face the same direction.

15. The cover plate assembly according to claim 11, wherein: The body has a second surface configured to face away from the inner cavity of the single battery. The pressure ring is welded to the body, and a weld mark formed by the welding does not protrude from the second surface.

16. A large-capacity single battery, characterized in that: include: a housing having an inner cavity; an electrode assembly, disposed in the inner cavity; a tab, one end of which is connected to the electrode assembly; And, in the cover plate assembly according to any one of claims 10-15, the other end of the tab passes through the first opening and is located in the tab installation space, and the tab is connected to the base plate and / or the body.

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