Pole, cover plate assembly and high-capacity single battery

Abstract

The invention 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. 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 present application relates to the field of battery technology, and in particular to a pole, a cover plate assembly and a large-capacity single battery. Background Art

[0002] As energy transforms towards green and low-carbon, power batteries, as a key technology to achieve low-carbon goals, are developing particularly rapidly. With the rapid development of power batteries, higher energy and reliability requirements are put forward for lithium batteries in all scenarios.

[0003] In the related art, a single cell 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. This part of the space that forms the height difference has two main functions. One is to provide space for arranging the pole ear and the conductive connecting piece connecting the pole ear and the pole, and the other is to increase the spacing between the pole ear and the electrode assembly to reduce the risk of the pole ear being invertedly inserted into the electrode assembly. Due to the existence of this part of the space, the internal space utilization rate of the single cell is low, resulting in a low energy density of the single cell. If part of the space is directly omitted, it is easy to cause the pole ear to be inverted into the electrode assembly, which in turn causes the single cell to fail. Therefore, how to avoid the pole ear being inverted into the electrode assembly while improving the energy density of the single cell is an urgent problem to be solved in the battery field. Summary of the invention

[0004] The embodiments of the present application provide a pole, a cover plate assembly and a large-capacity single cell, which can improve the energy density of the single cell while avoiding the inverted insertion of the pole tab into the electrode assembly.

[0005] In the first aspect, an embodiment of the present application provides a pole, which is applied to a single cell battery, and the pole includes a main body and a base plate; the base plate is connected to the main body, and a pole lug installation space is defined between the base plate and the main body; the main body and / or the base plate define a first opening, and the first opening is configured to connect the pole lug installation space with the inner cavity of the single cell battery.

[0006] In some embodiments, the body has a first surface configured to face the inner cavity of the single cell, and a groove is provided on the first surface; the bottom plate is arranged across the notch of the groove, and the bottom plate covers part of the notch of the groove, and the bottom plate and the inner wall of the groove define a tab installation space, and the other part of the notch is a first opening.

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

[0008] In one embodiment, a surface of the bottom plate facing away from the 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 protrudingly provided at a portion where the bottom plate overlaps with the first step groove, and the extension portion overlaps with 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 a 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, satisfying: 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 includes 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 battery; 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 circumference of the main body away from the pressure ring, 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 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.

[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 away from the cover plate, the receiving groove is configured to receive a portion of a tab of a single battery, 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, and 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 pole ear and the aforementioned cover assembly; the shell has an inner cavity; the electrode assembly is arranged in the inner cavity; one end of the pole ear is connected to the electrode assembly, and the other end passes through the first opening and is located in the pole ear installation space, and the pole ear is connected to the bottom plate and / or the body.

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

[0022] In the embodiment of the present application, by defining the tab installation space and the first opening connecting the tab with the inner cavity of the single cell, the tab can pass through the first opening and be located in the tab installation space. In this way, on the one hand, the tab and the pole column share the same height space, so that the space originally occupied by the tab can be used to set the electrode assembly, thereby improving the energy density of the single cell; on the other hand, the tab can be covered by the tab installation space, so that the wall of the tab installation space formed on the pole column isolates the end of the tab from the electrode assembly, thereby effectively preventing the tab from being inserted 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 drawings required for use in the description of the embodiments will be briefly introduced below. 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 diagram of the structure 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 is along Figure 2 Sectional view of AA in the middle;

[0027] Figure 4 It is a schematic diagram of the matching of the pole and the pole ear provided in the embodiment of the present application;

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

[0029] Figure 6 is along Figure 2 Cross-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] Fig. 9 is a side view of a first surface of yet another pole provided in an embodiment of the present application;

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

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

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

[0036] Fig.13 yes Fig.12 The enlarged view of point D in the middle;

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

[0038] Fig.15 It is a schematic diagram of the structure of a large-capacity single cell provided in an embodiment of the present application.

[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-bottom plate; 121-extension part; 122-reinforcement rib;

[0043] 013-Pole ear installation space;

[0044] 002-cover plate assembly; 021-cover plate; 211-mounting hole; 212-sinking platform; 022-pressing ring; 023-upper plastic part; 024-lower plastic part; 241-accommodating 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 the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work 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 used to limit the present application. In the present application, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0048] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to 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 includes a list of elements includes not only those elements but also other elements not explicitly listed, or also includes elements inherent to such process, method, article, or apparatus.

[0050] In the description of the embodiments of the present application, words such as "example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "example" or "for example" in the embodiments of the present application is not to be interpreted as being more preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to present relative concepts in a clear manner.

[0051] See also Figure 1-Figure 3 , Figure 1 is a schematic diagram of the structure of the pole 001 provided in an embodiment of the present application, Figure 2The embodiment of the present application provides a side view of the first surface 111 of the pole 001. Figure 3 is along Figure 2 In the cross-sectional view of AA, an embodiment of the present application provides a pole 001, which is applied to a single cell.

[0052] The pole 001 includes a body 011 and a bottom plate 012. The bottom plate 012 is connected to the body 011. A tab installation space 013 is 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 connect the tab installation space 013 with the inner cavity of the single cell.

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

[0054] Specifically, the end of the pole ear passes through the first opening 113 and is located in the pole ear installation space 013. At the same time, the pole ear is electrically connected to the bottom plate 012 or the body 011, or the pole ear is electrically connected to the bottom plate 012 and the body 011 at the same time, so as to realize the flow between the pole ear and the pole 001. Figure 4 As shown, Figure 4 It is a schematic diagram of the matching between the pole 001 and the pole ear provided in the embodiment of the present application.

[0055] Among them, since the pole ear is a foil material with a small thickness, the edges of the surfaces on the bottom plate 012 and the main body 011 configured to contact the pole ear are chamfered. Optionally, the edges of the surfaces on the bottom plate 012 and the main body 011 configured to contact the pole ear are chamfered to prevent the pole ear from being cut.

[0056] It can be understood that the portion where the bottom plate 012 is connected to the body 011 is a flow-through portion between the bottom plate 012 and the body 011. Specifically, the bottom plate 012 and the body 011 are welded.

[0057] In this embodiment, by defining the tab installation space 013 and the first opening 113 communicating the tab with the inner cavity of the single cell, the tab can pass through the first opening 113 and be located in the tab installation space 013. In this way, on the one hand, the tab and the pole 001 share the same height space, so that the space originally occupied by the tab can be used to set the electrode assembly, thereby improving the energy density of the single cell; on the other hand, the tab can be covered by the tab installation space 013, so that the part of the wall of the tab installation space 013 formed on the pole 001 isolates the end of the tab from the electrode assembly, thereby effectively preventing the tab from being inserted into the electrode assembly, thereby improving the reliability of the single cell.

[0058] In addition, in this embodiment, the pole 001 is directly connected to the tab, thereby eliminating the conductive connecting sheet connecting the tab and the pole 001. In this way, not only can the number of parts of the single battery be reduced to control the relevant cost and improve the assembly efficiency, but also the space used for arranging the conductive connecting sheet can be used for arranging the electrode assembly to improve the energy density of the single battery.

[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 battery. The first surface 111 is provided with a groove 112. The bottom plate 012 is arranged across the notch of the groove 112. The bottom plate 012 covers part of the notch of the groove 112 and defines a tab installation space 013 with the inner wall of the groove 112. The other part of the notch is a first opening 113.

[0060] When the bottom plate 012 is disposed in the middle of the notch of the groove 112, the notch located on both sides of the bottom plate 012 defines a first opening 113. In this way, a portion of the tabs enters the tab installation space 013 from a first opening 113, and another portion of the tabs enters the tab installation space 013 from another first opening 113. In this way, the symmetry of the tab arrangement can be improved to improve the force uniformity of the single cell.

[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 a tab installation space 013, which is configured to cooperate with the tab of the single 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 spacing between the bottom plate 012 and the bottom of the groove 112 is D, which satisfies: 0.5mm≤D≤5mm. According to different types of batteries and the corresponding number of layers of positive and negative tabs, the spacing between the bottom plate 012 and the bottom of the groove 112 can be adaptively designed.

[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 groove wall of the groove 112 and be located between the groove bottom of the groove 112 and the bottom plate 012. In this way, on the one hand, the pole 001 has a simple structure and is easy to form; on the other hand, the end of the tab can be isolated from the electrode assembly by the bottom plate 012, thereby effectively preventing the tab from being inserted into the electrode assembly in reverse, thereby improving the reliability of the single cell.

[0065] See also Figure 5 and Figure 6 , Figure 5 is a schematic diagram of the structure of the main body 011 provided in the embodiment of the present application, Figure 6 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 groove opening of the groove 112. Both ends of the bottom plate 012 overlap the two first step grooves 114 respectively.

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

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

[0068] Please refer to the figure Figure 3 and Figure 7 , Figure 7 yes Figure 6 The enlarged view of the point C in the middle. 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 has a depth dimension of the first step groove 114 .

[0071] In this embodiment, by limiting the thickness of the bottom 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 ensure that the bottom plate 012 has appropriate strength to meet the isolation requirements between the tab and the electrode assembly, and can also ensure that the bottom plate 012 and the main body 011 have an appropriate contact surface area to meet the flow requirements between the bottom plate 012 and the main body 011.

[0072] See also Figure 8 , Figure 8 1 is a side view of the first surface 111 of another pole 001 provided in an embodiment of the present application. In one embodiment, along the extension direction of the first step groove 114, an extension portion 121 is protruded from the portion where the bottom plate 012 overlaps 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 main body 011 can be increased to improve the current flow capacity between the base plate 012 and the main body 011; on the other hand, the area of ​​the welding surface between the base plate 012 and the main body 011 can be increased to improve the welding strength between the base plate 012 and the main body 011, thereby improving the structural stability of the pole 001.

[0074] See also Fig. 9 , Fig. 9 001 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 bottom plate 012. Both sides of the reinforcing rib 122 are connected to the extension 121 and the bottom 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 , thereby 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 outwardly turned edge 115 is provided on one 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 outwardly turned edge 115 , the matching area between the pole 001 and the top cover of the single cell can be enlarged, thereby improving the position stability of the pole 001 when installed on the single cell.

[0079] See also Fig.10 , Fig.10 001 is a cross-sectional view of another pole 001 provided in an embodiment of the present application. In one embodiment, along the axial direction of the pole 001, the body 011 includes a first connector 116 and a second connector 117. One side of the first connector 116 is connected to one side of the second connector 117. A groove 112 is provided on the other side of the first connector 116. The bottom plate 012 is connected to the first connector 116. The material of the first connector 116 and the material of the bottom plate 012 are consistent with the material of the pole ear electrically connected to the single cell, and the second connector 117 is aluminum.

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

[0081] Among them, since the groove 112 is provided on the second connecting member 117, the second connecting member 117 is connected to the first connecting member 116 near the portion opposite to the groove 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, so as to ensure the connection strength between the first connecting member 116 and the second connecting member 117 of different materials.

[0082] In this embodiment, through the above 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 configured to be away from the inner cavity of the single cell. A second step groove 118 is provided on the periphery of the second surface 119. A third step groove 119a is provided on the outer peripheral surface of the body 011. Along the axial direction of the pole 001, the second step groove 118 and the third step groove 119a are sequentially arranged away from the second surface 119. The portion on the outer peripheral surface of the body 011 located on the side of the third step groove 119a close to the second surface 119 is configured to cooperate with the pressure ring of the single cell.

[0084] It can be understood that the body 011 away from the inner cavity of the single cell needs to be sleeved with the pressure ring 022 to fix the pole 001 to the cover plate 021 of the single cell in the axial direction in combination with the outer edge 115. The pressure ring 022 needs to be welded and fixed to the body 011. The weld mark formed by welding has a certain height dimension.

[0085] Based on this, in this embodiment, by providing the second step groove 118, the weld mark formed by welding between the body 011 and the pressure ring 022 can be located in the second step groove 118, thereby improving the flatness of the second surface 119 of the electrode 001 and the pressure ring 022, and further improving the flatness of the electrode 001 and the connection bar when they are attached. In this way, the reliability of the welding between the electrode 001 and the connection bar can be improved, and cold welding can be effectively avoided.

[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 being too large to affect the strength of the pole 001 .

[0089] See also Fig.11 and Fig.12 , Fig.11 is an exploded view of the cover plate assembly 002 provided in an embodiment of the present application, Fig.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] It can be understood that the cover plate assembly 002 further includes a pressure ring 022, an upper plastic part 023, a lower plastic part 024 and a sealing ring 025. The pressure ring 022 is sleeved on the side of the body 011 away from the inner cavity of the single battery. The upper plastic part 023 is arranged between the pressure ring 022 and the cover plate 021. The lower plastic part 024 is arranged on the side of the cover plate 021 away from the upper plastic part 023. The sealing ring 025 seals the cover plate 021 and the body 011.

[0091] The distance between the side of the pressure ring 022 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 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 Fig.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 pole 001, the pole tab can pass through the first opening 113 and be located in the pole tab installation space 013. In this way, on the one hand, the pole tab and the pole 001 share the same height space, so that the space originally occupied by the pole tab can be used to set the electrode assembly, thereby improving the energy density of the single battery; on the other hand, the pole tab can be covered by the pole tab installation space 013, so that the part of the wall of the pole tab installation space 013 formed on the pole 001 isolates the end of the pole tab from the electrode assembly, thereby effectively preventing the pole tab from being inserted into the electrode assembly, thereby improving the reliability of the single battery.

[0094] See also Fig.13 , Fig.13 yes Fig.12 Enlarged view of point D in the figure. In one embodiment, the outer peripheral surface of the body 011 is provided with an outward turning edge 115 that cooperates with the cover plate 021 to stop it on the side facing away from the pressure ring 022. A sink 212 is provided on the side of the cover plate 021 facing the inner cavity of the single battery. The mounting hole 211 passes through the bottom wall of the sink 212. The inner peripheral surface and the outer peripheral surface of the sealing ring 025 are respectively sealed with the outer peripheral surface of the body 011 and the peripheral wall of the sink 212. The two end faces of the sealing ring 025 are respectively sealed with the bottom wall of the sink 212 and the outward turning edge 115.

[0095] The outer peripheral surface of the outwardly 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 peripheral surfaces and two end surfaces of the sealing ring 025 are used as sealing surfaces, so that the sealing between the cover plate 021 and the pole 001 can be improved, thereby improving the reliability of the single battery.

[0097] See also Fig.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 this embodiment, after the sealing ring 025 is assembled, the bottom plate 012 needs to be welded to 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 between the cover plate 021 and the pole 001 after the bottom plate 012 and the body 011 are welded.

[0101] See also Fig.14 , Fig.14 024 is a partial structural diagram of the lower plastic part 024 provided in an embodiment of the present application. In one embodiment, a receiving groove 241 is provided on the side of the lower plastic part facing away from the cover plate 021. The receiving groove 241 is configured to receive a portion of the tab of a single cell. The receiving groove 241 is provided adjacent to the first opening 113, and the opening of the receiving groove 241 faces the same direction as the first opening 113.

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

[0103] The receiving groove 241 is disposed adjacent to the first opening 113 and is located on the side of the first opening 113 away from the bottom plate 012. There are two first openings 113, and the two first openings 113 are respectively located on both sides of the bottom plate 012. Accordingly, there are two receiving grooves 241, and they are respectively located on the side of the two first openings 113 away from the bottom plate 012.

[0104] In this embodiment, by providing the receiving groove 241, the lower plastic part 024 not only plays the role of insulating and protecting the electrode assembly and the cover plate 021, but also can accommodate the bent electrode ear through the receiving groove 241, thereby effectively preventing the electrode ear from being inserted upside down into the electrode assembly.

[0105] In one 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 allow the lower plastic part 024 to have enough space to accommodate the pole ear and the conductive connecting sheet, the minimum height of the lower plastic part 024 is 5 mm. In this embodiment, the pole ear is made to share the height space with the pole column 001, and the pole ear is blocked by the bottom plate 012 to prevent the pole ear from being inserted into the electrode assembly in reverse. In this way, in this embodiment, the height dimension of the lower plastic part 024 can be reduced to 2 mm. Therefore, this embodiment can not only increase the size of the electrode assembly to improve the energy density of the single cell, but also reduce the material cost of the lower plastic part 024 to control the cost of the single cell.

[0107] See also Fig.12 and Fig.13 In one embodiment, the body 011 has a second surface 119 configured to be away from the inner cavity of the single battery. The pressure ring 022 is welded to the body 011 , and the weld mark formed by the welding 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 welding mark formed by the welding of the pressure ring 022 and the body 011 not to protrude from the second surface 119, the flatness of the second surface 119 where the pole 001 and the pressure ring 022 are welded can be improved, and the flatness of the pole 001 and the connecting bar when they are attached can be improved. In this way, the reliability of the welding between the pole 001 and the connecting bar can be improved, and cold welding can be effectively avoided.

[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 Fig.15 , Fig.15 003 is a schematic diagram of the structure of a large-capacity single cell 003 provided in an embodiment of the present application. Accordingly, an embodiment of the present application also provides a large-capacity single cell 003. The large-capacity single cell 003 includes a shell 031, an electrode assembly 032, a pole ear 033 and the aforementioned cover assembly 002. The shell 031 has an inner cavity 311. The electrode assembly 032 is disposed in the inner cavity 311. One end of the pole ear 033 is connected to the electrode assembly 032, and the other end passes through the first opening 113 and is located in the pole ear installation space 013, and the pole ear 033 is connected to the bottom plate 012 and / or the 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 located between the bottom of the groove 112 and the bottom plate 012 after the first opening 113. In this way, on the one hand, the tab 033 and the pole 001 share the same height space, so that the space originally occupied by the tab 033 can be used to set the electrode assembly 032, thereby improving the energy density of the large-capacity single battery 003; on the other hand, the tab can be covered by the tab installation space 013, so that the part of the wall of the pole tab installation space 013 formed on the pole 001 isolates the end of the tab 033 from the electrode assembly 032, thereby effectively preventing the tab 033 from being inserted into the electrode assembly 032, thereby improving the reliability of the large-capacity single battery 003.

[0116] The embodiments of the present application are introduced in detail above. Specific examples are used in this article 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 technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method 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 is connected to the body, a tab installation space is defined between the bottom plate and the body, the body and / or the bottom plate define a first opening, and the first opening is configured to connect the tab installation space with the inner cavity of the single battery.

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 another 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 arranged adjacent to the groove opening, and two ends of the bottom plate are overlapped with the two first step grooves respectively.

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 protrudingly provided at a portion where the bottom plate overlaps with the first step groove, and the extension portion overlaps with the first step groove.

7. The pole according to claim 6, characterized in that: A reinforcing rib is arranged in the included angle formed between the extension part and the bottom plate, and two sides of the reinforcing rib are respectively connected to the extension part 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 be 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 arranged on the outer circumferential surface of the main 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 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 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, satisfying: 2%H≤d2≤10%H.

10. A cover plate assembly, characterized in that: include: A cover plate, 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, characterized in that: The cover plate assembly also includes: A pressure ring, sleeved on a side of the body away from the inner cavity of the single battery; An upper plastic part, arranged between the pressure ring and the cover plate; A lower plastic part, arranged on a side of the cover plate 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, characterized in that: The outer circumferential surface of the main body is provided with an outward turning edge cooperating with the cover plate on the side away from the pressure ring, 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 circumferential surface and the outer circumferential surface of the sealing ring are respectively sealed with the outer circumferential surface 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, characterized in that: 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, characterized in that: A receiving groove is provided on a side of the lower plastic away from the cover plate, and the receiving groove is configured to receive a portion of the tab of the single battery. The receiving groove is disposed adjacent to the first opening, and the opening of the receiving groove faces the same direction as the first opening.

15. The cover plate assembly according to claim 11, characterized in that: The body has a second surface configured to face away from the inner cavity of the single battery, and 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 cell battery, characterized in that: include: a housing having an inner cavity; an electrode assembly, disposed in the inner cavity; A pole ear, one end of which is connected to the electrode assembly; And, in the cover plate assembly as described in any one of claims 10-15, the other end of the pole lug passes through the first opening and is located in the pole lug installation space, and the pole lug is connected to the base plate and / or the body.

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