Lithium battery cover plate and lithium battery

Abstract

The utility model discloses a lithium battery cover plate, which comprises positive electrode upper plastic cement, positive electrode lower plastic cement and positive electrode upper plastic cement double through holes, the negative electrode upper plastic comprises negative electrode upper plastic double through holes; a substrate positive electrode double-through hole and a substrate negative electrode double-through hole are symmetrically distributed in the two sides of the substrate; a lower plastic positive electrode double-through hole and a lower plastic negative electrode double-through hole are symmetrically distributed on two sides of the lower plastic; the positive electrode bipolar column comprises a positive electrode double-column body and a positive electrode column base which are integrally formed; the cathode double-pole column comprises a cathode double-pole body and a cathode column base which are integrally formed; wherein in the first direction, the positive electrode double-column body sequentially penetrates through the lower plastic positive electrode double-through hole, the substrate positive electrode double-through hole and the positive electrode upper plastic double-through hole, and the negative electrode double-column body sequentially penetrates through the lower plastic negative electrode double-through hole, the substrate negative electrode double-through hole and the negative electrode upper plastic double-through hole, the positive electrode column base and the negative electrode column base are attached to the lower plastic. The lithium battery cover plate can improve the overcurrent capability of the lithium battery and is simple to assemble. The utility model also discloses a lithium battery.

Description

Technical Field

[0001] The utility model relates to the field of new batteries, in particular to a lithium battery cover and a lithium battery. Background Art

[0002] In recent years, with the rapid development of the new energy vehicle field, the demand for lithium batteries in the market has continued to grow. Charging anxiety and battery life anxiety have always been the focus of people's attention. Therefore, supercharging / fast charging batteries have become a new hot spot in the technology competition among major power lithium battery companies in the industry. Against this background, research on power battery structural components that can meet the battery fast charging performance requirements has also become a key direction, requiring battery structural components to have sufficiently large current and heat dissipation capabilities.

[0003] The traditional square power battery cover structure currently in the industry mostly adopts the one-piece injection molding and riveting molding process of a single positive and negative pole. The cover structure of a single positive and negative pole has the disadvantages of a small width of the winding core tab, high heat generation during rate charging and discharging, and insufficient overcurrent capacity. It cannot meet the performance requirements of high-rate charging and discharging of large batteries. This problem can be improved by adding poles. However, in the case of adding poles, the battery cover structure may become more complicated, and more components will be required to connect in the cover structure, which will lead to an increase in impedance and a decrease in transmission efficiency. The difficulty of sealing is relatively increased when the structure is complex and the number of components increases, and the number of manufacturing processes increases, which reduces assembly efficiency. Utility Model Content

[0004] The embodiment of the utility model discloses a lithium battery cover, comprising:

[0005] Plastic on the positive electrode, including double through holes in the plastic on the positive electrode;

[0006] The plastic on the negative electrode includes a double through hole in the plastic on the negative electrode;

[0007] The substrate has a substrate positive double through hole and a substrate negative double through hole symmetrically distributed on both sides;

[0008] The lower plastic has double through holes for the positive electrode and double through holes for the negative electrode symmetrically distributed on both sides;

[0009] A positive electrode bipolar column, comprising an integrally formed positive electrode bipolar column and a positive electrode column base;

[0010] A negative electrode bipolar column, comprising an integrally formed negative electrode bipolar column and a negative electrode column base;

[0011] Among them, along the first direction, the positive electrode double pillars pass through the lower plastic positive electrode double through holes, the substrate positive electrode double through holes and the positive electrode upper plastic double through holes in sequence, and the negative electrode double pillars pass through the lower plastic negative electrode double through holes, the substrate negative electrode double through holes and the negative electrode upper plastic double through holes in sequence, the positive electrode column base and the negative electrode column base and the lower plastic.

[0012] By adopting the above technical solution, the simple structure of the battery cover can be maintained while adding poles, and the components are reliably connected and well sealed, ensuring the battery's strong flow and heat conduction capabilities, and the manufacturing process is convenient and the production efficiency is high.

[0013] Optionally, a positive electrode connecting piece and a negative electrode connecting piece are further included, wherein the positive electrode connecting piece and the negative electrode connecting piece are respectively attached to the positive electrode column base and the negative electrode column base, and the positive electrode connecting piece and the negative electrode connecting piece are respectively an integrated structure.

[0014] Optionally, along the width direction of the lower plastic, the negative electrode connecting piece has two symmetrically distributed welding parts, the welding parts are used to weld the electrode ears, the two welding parts are connected by a bridge part, and along the length direction of the lower plastic, the two side edges of the bridge part are relatively concave arcs.

[0015] Optionally, along the width direction of the lower plastic, the positive electrode connecting piece has two symmetrically distributed welding parts, the welding parts are used to weld the electrode tabs, the two welding parts are connected by a bridge part, and along the length direction of the lower plastic, the two side edges of the bridge part are straight lines.

[0016] Optionally, the positive electrode double cylinder and the negative electrode double cylinder are respectively provided with sealing rings.

[0017] Optionally, after the positive electrode double cylinder is sleeved with the sealing ring, it passes through the lower plastic positive electrode double through holes and the substrate positive electrode double through holes in sequence. The positive electrode upper plastic is obtained by injection molding, and the positive electrode upper plastic can seal and connect the substrate, the lower plastic and the positive electrode bipolar column; and / or, after the negative electrode double cylinder is sleeved with the sealing ring, it passes through the lower plastic negative electrode double through holes and the substrate positive electrode double through holes in sequence. The negative electrode upper plastic is obtained by injection molding, and the negative electrode upper plastic can seal and connect the substrate, the lower plastic and the negative electrode bipolar column.

[0018] Optionally, the plastic on the positive electrode is a PPS conductive material, and the resistance of the plastic on the positive electrode is 20Ω to 10000Ω, and / or the plastic on the negative electrode is a PPS insulating material.

[0019] Optionally, the end faces of the positive electrode double cylinder and the negative electrode double cylinder are circular, and / or the end faces of the positive electrode double cylinder and the negative electrode double cylinder have a diameter of 10.5 to 30 mm.

[0020] Optionally, an explosion-proof valve hole is provided in the center of the substrate, the explosion-proof valve hole is used for embedding an explosion-proof valve, and an explosion-proof valve patch is affixed to the explosion-proof valve.

[0021] According to another specific embodiment of the present invention, the embodiment of the present invention discloses a lithium battery having the above-mentioned lithium battery cover.

[0022] The above technical solution can enhance the current and heat conduction capabilities of lithium batteries without increasing the difficulty of manufacturing lithium batteries. It is particularly suitable for supercharging / fast charging, and the battery structure connection is reliable and the performance is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 An exploded view showing the overall structure of a lithium battery cover according to one embodiment of the present invention;

[0024] Figure 2 A schematic diagram showing the planar structure of a lithium battery cover according to one embodiment of the present invention is shown;

[0025] Figure 3 Another schematic plan view showing the structure of a lithium battery cover according to one embodiment of the present invention;

[0026] Figure 4 A schematic diagram showing an ultrasonic welding mark of a lithium battery cover plate according to one embodiment of the present invention;

[0027] Figure 5 Another schematic diagram showing the ultrasonic welding of a lithium battery cover according to one embodiment of the present invention.

[0028] 1. Plastic on the positive electrode, 11. Double through-holes on the plastic on the positive electrode, 2. Plastic on the negative electrode, 21. Through-holes on the plastic on the negative electrode, 3. Substrate,

[0029] 31. Double through-holes for the positive electrode of the substrate, 32. Double through-holes for the negative electrode of the substrate, 33. Holes for explosion-proof valve, 34. Explosion-proof valve, 35. Explosion-proof valve patch,

[0030] 4. Lower plastic, 41. Lower plastic positive electrode double through holes, 42. Lower plastic negative electrode double through holes, 5. Positive bipolar column, 51. Positive bipolar body, 52. Positive column base, 6. Negative bipolar column, 61. Negative bipolar body, 62. Negative column base, 7. Sealing ring, 8. Positive connecting piece, 81. Welding part, 82. Bridge part, 9. Negative connecting piece, 91. Welding part, 92. Bridge part. DETAILED DESCRIPTION

[0031] The following is an explanation of the implementation of the present invention by means of specific specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this utility model are limited to this implementation. On the contrary, the purpose of introducing the utility model in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide an in-depth understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0032] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0033] In the description of this embodiment, it should be noted that, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this embodiment based on specific circumstances.

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0035] The first aspect of the present invention discloses a lithium battery cover. In a specific embodiment of the present invention, Figure 1 As shown, combined Figure 2-3 , which includes:

[0036] The positive electrode plastic 1 includes a double through hole 11 on the positive electrode plastic;

[0037] The negative electrode plastic 2 includes a negative electrode plastic double through hole 21;

[0038] The substrate 3 has a substrate positive electrode double through hole 31 and a substrate negative electrode double through hole 32 symmetrically distributed on both sides;

[0039] The lower plastic 4 has two symmetrically distributed lower plastic positive electrode double through holes 41 and lower plastic negative electrode double through holes 42;

[0040] The positive electrode bipolar column 5 includes an integrally formed positive electrode bipolar column 51 and a positive electrode column base 52;

[0041] The negative electrode bipolar column 6 includes an integrally formed negative electrode bipolar body 61 and a negative electrode column base 62;

[0042] Among them, along the first direction, the positive electrode double column 51 sequentially passes through the lower plastic positive electrode double through-hole 41, the substrate positive electrode double through-hole 31 and the positive electrode upper plastic double through-hole 11, and the negative electrode double column 61 sequentially passes through the lower plastic negative electrode double through-hole 42, the substrate negative electrode double through-hole 32 and the negative electrode upper plastic double through-hole 21, and the positive electrode column base 52 and the negative electrode column base 62 are attached to the lower plastic 4. Specifically, the first direction coincides with the thickness direction of the substrate 3, for example Figure 1 Direction A shown in .

[0043] The positive electrode double column 51 and the negative electrode double column 61 can improve the battery's current capacity, and the current capacity is strong in large cells. Furthermore, the positive electrode double column 51 and the positive electrode column base 52 are integrally formed, and the negative electrode double column 61 and the negative electrode column base 62 are integrally formed. In addition, the lower plastic 4, the upper plastic, and the substrate 3 are all provided with corresponding double through-holes. There is no need to separately install and fix the four poles. The positive and negative poles only need to pass through these double through-holes, and the lithium battery cover is basically assembled. The connection structure is simple, and no additional connecting parts are required. It can ensure the stability of the cover structure while ensuring the transmission efficiency and current capacity. Furthermore, although the positive electrode double column 51 and the negative electrode double column 61 pass through the lower plastic 4, the positive electrode column base 52 and the negative electrode column base 62 do not pass through, but are attached to the bottom of the lower plastic 4, ensuring the stability of the bipolar column structure in the cover. Moreover, with the cooperation of the positive electrode column base 52, the negative electrode column base 62, the lower plastic 4, the substrate 3 and the upper plastic, the sealing performance and connection performance of the cover can be further ensured.

[0044] In a specific embodiment of the present invention, specifically, the positive bipolar column 5 is made of an aluminum alloy material in one piece, and the negative bipolar column 6 is made of a copper-aluminum friction welding composite material in one piece, to ensure stable performance of the bipolar column.

[0045] In a specific embodiment of the present invention, the positive electrode double cylinder 51 and the negative electrode double cylinder 61 are preferably rectangular parallelepiped, cube, or cylinder. That is, the cross-sections of the positive electrode double cylinder 51 and the negative electrode double cylinder 51 can be either circular or rectangular. Preferably, both the positive electrode double cylinder 51 and the negative electrode double cylinder 61 are cylindrical, that is, the end faces of the positive electrode double cylinder 5 and the negative electrode double cylinder 6 are circular, which improves working efficiency. Furthermore, the positive electrode column base 52 and the negative electrode column base 62 are thin sheets, for example, which can be rectangular. Furthermore, the four corners of the sheet have a certain curvature to prevent damage to other components.

[0046] In a specific embodiment of the present invention, preferably, the diameter of the end faces of the positive electrode double cylinder 5 and the negative electrode double cylinder 6 is 10.5 to 30 mm, based on the circular end faces. In other words, the diameter of the welding surface is 10.5 to 30 mm, and the lithium battery can be adapted to various application scenarios and can be adjusted according to the battery thickness.

[0047] In one specific embodiment of the present invention, the positive and negative bipolar columns 51 and 61 are each further fitted with a sealing ring 7. For example, if the positive and negative bipolar columns 51 and 61 are cylindrical, the sealing ring 7 is circular. Simultaneously, the assembly and connection of the various components creates a stable seal between the positive and negative bipolar columns 5, 6, sealing ring 7, substrate 3, positive upper plastic 1, negative upper plastic 2, and lower plastic 4, ensuring proper battery function.

[0048] In a specific embodiment of the present invention, the positive electrode upper plastic 1 and the negative electrode upper plastic 2 are formed by an injection molding process. Specifically, the positive electrode double cylinder 5 is fitted with a sealing ring 7 and then sequentially passes through the lower plastic positive electrode double through-holes 41 and the substrate positive electrode double through-holes 31. Subsequently, the positive electrode upper plastic 1 is formed by injection molding. The positive electrode upper plastic 1 can be sealed and connected to the substrate 3, the lower plastic 4, and the positive electrode bipolar column 5. The negative electrode double cylinder 6 is fitted with a sealing ring 7 and then sequentially passes through the lower plastic negative electrode double through-holes 42 and the substrate negative electrode double through-holes 32. Subsequently, the negative electrode upper plastic 2 is formed by injection molding. The negative electrode upper plastic 2 can be sealed and connected to the substrate 3, the lower plastic 4, and the negative electrode bipolar column 6.

[0049] In other words, when assembling the cover, the positive electrode upper plastic 1 and the negative electrode upper plastic 2 are not pre-fabricated from the outset. Instead, they are directly injection-molded onto the double cylinder, sealing ring 7, lower plastic 4, and base plate 3, after they are assembled. Therefore, the positive electrode upper plastic 1 and the negative electrode upper plastic 2 securely connect all components and improve the sealing of the lithium battery cover. This manufacturing and assembly process is simpler, improves production efficiency, and ensures a secure connection between components, providing strong sealing performance, further enhancing the stability and safety of the lithium battery's performance.

[0050] In a specific embodiment of the present invention, the plastic 1 on the positive electrode is a PPS conductive material, and the resistance of the plastic 1 on the positive electrode is 20Ω to 10000Ω.

[0051] In a specific embodiment of the present invention, the plastic 2 on the negative electrode is a PPS insulating material.

[0052] In a specific embodiment of the present invention, Figure 1 、 Figure 2 and Figure 4The lithium battery cover also includes a positive electrode connector 8 and a negative electrode connector 9. The positive electrode connector 8 and the negative electrode connector 9 are respectively attached to the positive electrode column base 52 and the negative electrode column base 62, and the positive electrode connector 8 and the negative electrode connector 9 are respectively integral structures. In other words, the positive electrode connector 8 is an integral structure, rather than a split structure. Similarly, the negative electrode connector 9 is an integral structure, rather than a split structure, thereby achieving more uniform current conduction.

[0053] In a specific embodiment of the present invention, along the width direction of the lower plastic 4 (such as Figure 2 In the direction B shown in FIG, the positive electrode connecting piece 8 has two symmetrically distributed welding parts 81, the welding parts 81 are used to weld the pole ears, and the two welding parts 81 are connected by a bridge part 82. Figure 2 The positive electrode connecting piece 8 is formed into a horizontal "H" shape, or an "I" shape, wherein the welding portion 81 is the two longer horizontal lines in the "H" shape or the "I" shape, which can be used for welding the tabs, specifically ultrasonic welding, such as Figure 4 、 Figure 5 As shown, the width of the matching wound / stacked core tabs can be lengthened, or the number of tabs can be increased. Correspondingly, the length or number of ultrasonic welds between the tabs and the connecting tabs can be increased, thereby improving the current carrying capacity. The bridge portion 82 is the shorter horizontal line of the "H" or "I" shape.

[0054] In a specific embodiment of the present invention, along the width direction of the lower plastic 4, the negative electrode connecting piece 9 has two symmetrically distributed welding parts 91, the welding parts 91 are used to weld the tabs, and the two welding parts 91 are connected by a bridge part 92. Figure 2 The negative electrode connecting piece 9 is formed into a horizontal "H" shape or an "I" shape. The welding portion 91 is the two longer horizontal lines in the "H" shape or the "I" shape, which can be used to weld the tabs. Specifically, ultrasonic welding can be used. Figure 4 、 Figure 5 As shown, different ultrasonic welding methods can be used. The width of the corresponding wound / stacked core tabs can be increased, or the number of tabs can be increased. Correspondingly, the length or number of ultrasonic weld marks between the tabs and the connecting tabs can be increased, thereby improving the current carrying capacity. The bridge portion 92 is the shorter horizontal line of the "H" or "I" shape.

[0055] Preferably, the bridge portion 82 of the positive electrode connecting sheet 8 and the bridge portion 92 of the negative electrode connecting sheet 9 have different shapes, which can be used to distinguish the positive electrode connecting sheet 8 from the negative electrode connecting sheet 9 and facilitate the correct assembly of the cover plate and the lithium battery.

[0056] Specifically, if Figure 2 As shown, along the length direction of the lower plastic 4 (as Figure 2In the direction C shown in FIG, the edges of bridge portion 92 are relatively concave arcs, while the edges of bridge portion 82 are straight lines. It can be considered that bridge portions 82 and 92 are both U-shaped notches on positive and negative electrode connecting tabs 8 and 9, but the curvature of the "U" is different.

[0057] In a specific embodiment of the present invention, Figure 1 As shown, combined with Figure 3 An explosion-proof valve hole 33 is provided at the center of the substrate 3. The explosion-proof valve hole 33 is used to embed an explosion-proof valve 34. An explosion-proof valve patch 35 is affixed to the explosion-proof valve 34. The explosion-proof structure can ensure the safety of the battery.

[0058] The second aspect of the present invention discloses a lithium battery having the lithium battery cover plate described in the above embodiments. The lithium battery has good current flow capacity and heat dissipation capacity, can meet the requirements of high-rate charging and discharging in large battery cells, and is simple to manufacture and has a stable structure.

[0059] Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above description is provided to further illustrate the present invention in conjunction with specific embodiments, and that the present invention should not be construed as being limited to these descriptions. Those skilled in the art may make various changes in form and detail, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A lithium battery cover, characterized in that: include: Plastic on the positive electrode, including double through holes in the plastic on the positive electrode; The plastic on the negative electrode includes a double through hole in the plastic on the negative electrode; The substrate has a substrate positive double through hole and a substrate negative double through hole symmetrically distributed on both sides; The lower plastic has double through holes for the positive electrode and double through holes for the negative electrode symmetrically distributed on both sides; A positive electrode bipolar column, comprising an integrally formed positive electrode bipolar column and a positive electrode column base; A negative electrode bipolar column, comprising an integrally formed negative electrode bipolar column and a negative electrode column base; Among them, along the first direction, the positive electrode double pillars pass through the lower plastic positive electrode double through holes, the substrate positive electrode double through holes and the positive electrode upper plastic double through holes in sequence, and the negative electrode double pillars pass through the lower plastic negative electrode double through holes, the substrate negative electrode double through holes and the negative electrode upper plastic double through holes in sequence, and the positive electrode column base and the negative electrode column base are attached to the lower plastic.

2. A lithium battery cover according to claim 1, characterized in that: It also includes a positive electrode connecting piece and a negative electrode connecting piece, wherein the positive electrode connecting piece and the negative electrode connecting piece are respectively attached to the positive electrode column base and the negative electrode column base, and the positive electrode connecting piece and the negative electrode connecting piece are respectively an integrated structure.

3. A lithium battery cover as claimed in claim 2, characterized in that: Along the width direction of the lower plastic, the negative electrode connecting piece has two symmetrically distributed welding parts, which are used to weld the electrode tabs. The two welding parts are connected by a bridge part. Along the length direction of the lower plastic, the two side edges of the bridge part are relatively concave arcs.

4. A lithium battery cover as claimed in claim 2, characterized in that: Along the width direction of the lower plastic, the positive electrode connecting piece has two symmetrically distributed welding parts, which are used to weld the electrode tabs. The two welding parts are connected by a bridge part. Along the length direction of the lower plastic, the two side edges of the bridge part are straight lines.

5. The lithium battery cover according to claim 1, wherein: The positive electrode double cylinder and the negative electrode double cylinder are also respectively sleeved with sealing rings.

6. A lithium battery cover as claimed in claim 5, characterized in that: The positive electrode double column is sleeved with the sealing ring and sequentially passes through the lower plastic positive electrode double through-holes and the substrate positive electrode double through-holes. The positive electrode upper plastic is obtained by injection molding. The positive electrode upper plastic can seal and connect the substrate, the lower plastic and the positive electrode double column; and / or, After the negative electrode double column is sleeved with the sealing ring, it passes through the negative electrode double through holes of the lower plastic and the positive electrode double through holes of the substrate in sequence. The negative electrode upper plastic is obtained by injection molding, and the negative electrode upper plastic can seal and connect the substrate, the lower plastic and the negative electrode double column.

7. The lithium battery cover according to claim 1, wherein: The plastic on the positive electrode is a PPS conductive material, and the resistance of the plastic on the positive electrode is 20Ω to 10000Ω, and / or the plastic on the negative electrode is a PPS insulating material.

8. The lithium battery cover according to claim 1, wherein: The end faces of the positive electrode double cylinder and the negative electrode double cylinder are circular, and / or the end faces of the positive electrode double cylinder and the negative electrode double cylinder have a diameter of 10.5 to 30 mm.

9. The lithium battery cover according to claim 1, wherein: An explosion-proof valve hole is provided at the center of the base plate. The explosion-proof valve hole is used for embedding an explosion-proof valve. An explosion-proof valve patch is attached to the explosion-proof valve.

10. A lithium battery, characterized in that: The invention comprises a lithium battery cover as described in any one of claims 1 to 9.

Images