End cover assembly for rapid temperature control type lithium ion battery

Abstract

The utility model discloses an end cover assembly for a rapid temperature control type lithium ion battery, the end cover assembly comprises a cover plate main body, a pole and a core rod welding platform, the pole is arranged on the cover plate main body in a penetrating manner, the pole and the cover plate main body are mutually insulated, the core rod welding platform is arranged on the pole in a penetrating manner, and the core rod welding platform is arranged on the cover plate main body. A core rod hole is formed in the core rod welding platform in a penetrating manner, and the core rod welding platform is insulated from the pole; the end cover assembly adopts a split mounting type design, so that the overall processing difficulty is reduced, and the production efficiency is improved; the maintenance is convenient, the damaged part can be independently replaced, and the maintenance cost is reduced; through the mutual insertion arrangement mode, the installation position can be finely adjusted during assembly, the compatibility is better, meanwhile, the stress generated during expansion of the roll core can be absorbed, the deformation of the shell caused by overlarge internal stress is avoided, and the service life of the battery can be prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of lithium battery technology, and in particular relates to an end cap assembly for a fast-temperature-controlled lithium-ion battery. Background Technology

[0002] With the increasing severity of energy and environmental issues, countries around the world have intensified their research and development efforts in new energy vehicles. As a crucial component of electric vehicles, the research on power batteries is imperative. Lithium-ion batteries possess the characteristic of balanced performance. Excluding upgrades in raw materials, changes in formulation and processes that improve performance in certain areas inevitably lead to a decline in performance in others. Therefore, most technologies currently on the market have reached near-theoretical levels. Further improvements require fundamental innovative design.

[0003] Because batteries generate heat over long periods of use, and there is often a 10-20°C temperature difference between the internal and external temperatures of the battery during operation, existing battery packs have incorporated cooling systems in their design. However, the design of the existing battery end caps and terminals makes it difficult for existing batteries to achieve internal cooling.

[0004] Therefore, we need to design an end cap assembly for rapidly temperature-controlled lithium-ion batteries to solve these problems. Utility Model Content

[0005] The problem to be solved by this invention is to provide an end cap assembly for a fast-temperature-controlled lithium-ion battery.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0007] The title includes the end cap assembly comprising a cover plate body, an electrode post, and a mandrel welding platform. The electrode post is disposed through the cover plate body and is insulated from the cover plate body. The mandrel welding platform is disposed through the electrode post and is also provided with a mandrel hole. The mandrel welding platform is insulated from the electrode post.

[0008] Preferably, the pole post has a through mounting groove, a splicing ring is provided in the mounting groove, a connecting groove is provided on the outer wall of the pole post, the connecting groove is connected end to end and surrounds the pole post, and the pole post also has a plug-in groove, the plug-in groove is connected end to end and surrounds the mounting groove.

[0009] This design facilitates the connection and fixation between various components.

[0010] Preferably, the center point of the fixing groove, the center point of the pole knob, and the center point of the collector plate overlap each other.

[0011] Preferably, a through groove is provided through the main body of the cover plate, the pole is located in the through groove, and the edge of the through groove is inserted into the connecting groove on the outer wall of the pole.

[0012] Preferably, the outer wall of the mandrel welding platform is provided with a splicing groove, and the splicing groove surrounds the mandrel hole, with the splicing ring located inside the splicing groove.

[0013] This configuration ensures strong connection.

[0014] Preferably, a second insulating element and a lower plastic are provided at the joint between the through groove and the connecting groove. The lower plastic is annular and located between one inner wall of the connecting groove and one surface of the cover plate body. The pole post and the cover plate body are insulated from each other by the second insulating element and the lower plastic.

[0015] Preferably, a first insulating element is provided at the joint between the splicing ring and the splicing groove, and at the joint between the outer wall of the mandrel welding platform and the inner wall of the mounting groove, wherein the mandrel welding platform and the pole are insulated from each other by the first insulating element.

[0016] This design ensures both airtightness and insulation performance.

[0017] Preferably, a welding shoulder is provided on the inner wall of the mandrel hole.

[0018] This setup ensures the welding quality between the welding fluid guiding mandrel and the mandrel welding platform.

[0019] Preferably, the thickness T7 of the cover plate body is 1-4mm, the width is 10-200mm, and the length is 10-400mm.

[0020] Preferably, the electrode post is made of aluminum or copper-aluminum composite material, and the thickness of the electrode post is 0.5-3mm and the width is 0.5-10mm.

[0021] Preferably, the thickness of the lower plastic 26 is 0.2-2mm, and the distance between the lower plastic 26 and the edge of the cover plate body 25 is 0-2mm.

[0022] The advantages and positive effects of this utility model are:

[0023] The end cap assembly of this utility model adopts a modular design, which reduces the overall processing difficulty and improves production efficiency; it is easy to maintain and repair, and damaged parts can be replaced individually, reducing maintenance costs; through the interlocking arrangement, the installation position can be finely adjusted during assembly, resulting in better compatibility, and it can also absorb the stress generated when the core expands, preventing excessive internal stress from causing the outer shell to deform, thus extending the battery's lifespan. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is an exploded view of the end cap assembly of the present invention;

[0026] Figure 2 This is a schematic cross-sectional view of the end cap assembly of the present invention after assembly;

[0027] Figure 3 This is a schematic diagram of the overall assembly structure of the present invention;

[0028] Figure 4 This is a schematic diagram of the assembly structure of the core and the shell of the present invention;

[0029] Figure 5 This is a schematic diagram of the structure of the housing of the present invention;

[0030] Figure 6 This is a schematic diagram of the collector disk structure of the present invention;

[0031] Figure 7 This is a schematic diagram of the longitudinal section of the collector plate of the present invention;

[0032] Figure 8 This is a schematic diagram of the cross-section of the collector plate of the present invention;

[0033] Figure 9 This is a schematic diagram of the liquid-conducting core rod structure of the present invention;

[0034] Figure 10 This is a schematic diagram showing the positions of the liquid guiding hole and the positioning hole of the present invention;

[0035] Figure 11 This is a cross-sectional schematic diagram of the positive or negative electrode sheet of the present invention;

[0036] Figure 12 This is a schematic cross-sectional view of a stacked structure of the front layer of the core winding according to the present invention;

[0037] Figure 13 This is a schematic diagram of the electrode structure in one embodiment of the present invention;

[0038] Figure 14 This is a schematic diagram of the position structure of the tabs and the cutting area in another embodiment of the present invention;

[0039] Figure 15This is a schematic diagram of the angle of the cutting area.

[0040] The annotations in the attached figures are explained as follows:

[0041] 1. Shell; 11. Injection hole; 12. Explosion-proof valve; 2. End cap assembly; 21. Electrode post; 211. Mounting groove; 212. Insertion groove; 213. Splicing ring; 214. Connecting groove; 22. First insulating component; 23. Core rod welding platform; 231. Core rod hole; 232. Welding shoulder; 233. Splicing groove; 24. Second insulating component; 25. Cover plate body; 251. Through groove; 26. Lower plastic; 3. Collector plate; 31. Welding plate; 32. Electrode knob; 33. Fixing groove; 4. Liquid guiding core rod; 41. Liquid passage hole; 42. Positioning hole; 5. Core winding; 51. Electrode tab; 52. Cutting area; 531. Positive electrode sheet; 532. Negative electrode sheet; 533. Diaphragm; 5301. Current collector layer; 5302. Active material layer. Detailed Implementation

[0042] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0043] Furthermore, in the embodiments and claims, unless otherwise specified, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of this utility model involve terms such as "first," "second," etc., they are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0044] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0045] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements present. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0046] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0047] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0048] The present invention will be further described below with reference to the accompanying drawings:

[0049] An end cap assembly for a fast-temperature-controlled lithium-ion battery includes an electrode post 21, a first insulating component 22, a core rod welding platform 23, a second insulating component 24, a cover plate body 25, and a lower plastic 26. The cover plate body 25 has a thickness T7 of 1-4 mm, a width of 10-200 mm, and a length of 10-400 mm. A through groove 251 is provided through the cover plate body 25, and the electrode post 21 is located within the through groove 251. The electrode post 21 is not limited to a rounded-corner cuboid structure, but can also be a cylinder or other shapes. The thickness is 0.5-3mm and the width is 0.5-10mm. The positive electrode post 21 is made of aluminum and the negative electrode post 21 is made of copper-aluminum composite material. An installation groove 211 is provided through the post 21. A splicing ring 213 is provided in the installation groove 211. A connecting groove 214 is provided on the outer wall of the post 21. The connecting groove 214 is connected end to end and surrounds the post 21. The cover plate body 25 is inserted into the connecting groove 214. The second insulating component 24 and the lower plastic 26 are located at the joint between the main board and the connecting groove 214.

[0050] In this embodiment, the thickness of the lower plastic 26 is 0.2-2mm, and the distance between the lower plastic 26 and the edge of the cover plate body 25 is 0-2mm, ensuring insulation between the cover plate body 25 and the pole post 21. The pole post 21 is also provided with a plug groove 212, which is connected end to end and surrounds the mounting groove 211. The depth of the plug groove 212 is not less than the height of the electrode button 32 on the collector plate 3. When the end cover assembly 2 is assembled with the housing 1, the electrode button 32 on the collector plate 3 will be inserted into the plug groove 212 on the pole post 21. Then, the cover plate pole post 21 and the hollow collector plate 3 electrode button are electrically connected by laser penetration welding.

[0051] The mandrel welding platform 23 is located inside the mounting groove 211. A mandrel hole 231 is provided through the mandrel welding platform 23. The cross-sectional size of the mandrel hole 231 is the same as the cross-sectional size of the liquid guiding mandrel 4. The ratio of the perimeter of the liquid guiding mandrel 4 to the perimeter of the core 5 is 1.1-10. A splicing groove 233 is provided on the outer wall of the mandrel welding platform 23. The splicing groove 233 surrounds the mandrel hole 231. The splicing ring 213 is located inside the splicing groove 233. The first insulating element 22 is located at the joint between the splicing ring 213 and the splicing groove 233, as well as the joint between the outer wall of the mandrel welding platform 23 and the inner wall of the mounting groove 211, to ensure the insulation between the pole post 21 and the mandrel welding platform 23. When the end cap assembly 2 is assembled with the housing 1, the end of the liquid guiding mandrel 4 is inserted into the mandrel hole 231 on the mandrel welding platform 23. Finally, the welding shoulder 232 of the mandrel welding platform 23 is welded to the liquid guiding mandrel 4 using laser welding, thus connecting the mandrel welding platform 23 and the liquid guiding mandrel 4.

[0052] A rapid temperature-controlled lithium-ion battery includes a housing 1, a core 5, a liquid-conducting core rod 4, a current collector 3, and an end cap assembly 2. A through hole is provided in the middle of the housing 1. The core 5 and the liquid-conducting core rod 4 are both located in the through hole on the housing 1, and the core 5 is sleeved on the liquid-conducting core rod 4. The two ends of the core 5 are respectively provided with tabs. The length of the liquid-conducting core rod 4 is not less than the length of the through hole. The current collector 3 and the end cap assembly 2 are respectively located at the openings at both ends of the housing 1. The end cap assembly 2 is connected to the housing 1. The current collector 3 is located between the end cap assembly 2 and the core 5, and the current collector 3 is connected to the end cap assembly 2 and the tabs respectively. The two ends of the liquid-conducting core rod 4 pass through the end cap assembly 2 at both ends of the housing 1.

[0053] Specifically, the shell 1 is formed by extrusion profile, and the material can be any one of aluminum alloy, steel, copper alloy, or magnesium alloy. In this embodiment, the shell is prismatic in shape. Figure 1As shown, the length L1 of the casing 1 satisfies 10mm≤L1≤2000mm, the width H1 satisfies 10mm≤H1≤400mm, and the thickness T1 satisfies 10mm≤T1≤200mm. The wall thickness T2 of the narrow side and the wall thickness T3 of the wide side of the casing 1 satisfy 0.2mm≤T2≤8mm and 0.2≤T3≤8mm, respectively, and the ratio of T2 to T3 is 1 / 2. This setting is because the winding core 5 inside the battery casing 1 will expand during repeated charging and discharging. The expanded winding core 5 will squeeze the casing 1, causing the casing 1 to deform. Therefore, the strength of the casing 1 is increased by adjusting the wall thickness of the wide side of the casing 1. The radius R1 of the arc corner of the casing 1 satisfies 0mm≤R1≤100mm, and the length of the casing 1 can be arbitrarily cut according to the configuration requirements of the battery cell capacity.

[0054] Specifically, the liquid guiding core rod 4 has a positioning hole 42 and several liquid passage holes 41 through it along its length. The liquid passage holes 41 are symmetrically distributed along the positioning hole 42, and the positioning hole 42 has a circular cross-section, while the liquid passage holes 41 have an elongated cross-section. In this embodiment, the length L4 of the liquid guiding core rod 4 satisfies 10mm≤L4≤2000mm, the width H4 satisfies 10mm≤H4≤400mm, and the thickness T4 satisfies 3mm≤T4≤200mm; the width H5 of the liquid passage hole 41 satisfies 1mm≤H5≤160mm, and the height T5 satisfies 1mm≤T5≤160mm; the radius R4 of the arc on both sides of the liquid guiding core rod 4 satisfies 0mm≤R4≤100mm, and the angle of R4 is 10°-180°; the radius R3 of the positioning hole 42 satisfies 1mm≤R3≤100mm; the ratio of the surface area S (unit cm2) of the liquid guiding hole on the liquid guiding core rod 4 to the capacity Q (unit Ah) of the core 5 is 0.5-5. This setting can not only greatly reduce the proportion of structural components, but also ensure that the heat conduction efficiency of the coolant flowing through the liquid guiding hole is the highest during use.

[0055] An explosion-proof valve 12 and an injection hole 11 are provided on a narrow face of the housing 1. The injection hole 11 is used to inject electrolyte into the housing 1 after the end cap assembly 2 is sealed and connected to the housing 1. The explosion-proof valve 12 can release the pressure inside the housing 1 when the cell expands excessively to prevent the battery from exploding. The opening pressure of the explosion-proof valve 12 is 0.2-1 MPa, the valve width is 4-50 mm, the length is 4-100 mm, and it is located in the middle of the narrow face of the housing 1.

[0056] The injection hole 11 is a circular hole with a diameter of 1-10mm, and the distance between it and the explosion-proof valve 12 is 15-50mm.

[0057] The current collector includes a welding plate 31, a fixing groove 33, and a pole button 32. The pole button 32 has a ring structure and is set on the welding plate 31. The fixing groove 33 is opened on the welding plate 31 inside the pole button 32. The current collector is integrally stamped and formed, which enables the current collector 3 to have higher mechanical strength. The material is aluminum or nickel-plated copper, which enables the current collector 3 to have good electrical conductivity.

[0058] The center points of the fixing groove 33, the pole knob 32, and the collector plate 3 overlap, ensuring the installation and fit accuracy with other components. Furthermore, the shape of the pole knob 32 is identical to that of the fixing groove 33.

[0059] In this embodiment, the welding plate 31 has a width W2 of 10-200mm, a length L2 of 10-200mm, and a thickness T6 of 0.2-1.8mm; the pole button 32 has a width W3 of 0.5-3mm, a height H2 of 1-10mm, and a fixing groove 33 has a length of 10-200mm and a width of 2.5-200mm.

[0060] The core 5 is obtained by stacking and winding a positive electrode sheet 531, a negative electrode sheet 532, and at least two layers of separators 533. The positive electrode sheet 531 and the negative electrode sheet 532 include a current collector layer 5301 and an active material layer 5302. The active material layer 5302 is coated on both sides of the current collector layer 5301, and an area without active material coating is reserved at one edge of the current collector layer 5301. The cross-section of the wound core 5 is racetrack-shaped, and the positive electrode sheet 531, the negative electrode sheet 532, and the separators 533 are arranged in a separator 533-positive electrode sheet 531-separator configuration. The membrane 533-negative electrode 532 or separator 533-negative electrode 532-separator 533-positive electrode 531 structure is stacked. Generally, gold foil is used as the current collector layer 5301 of the positive electrode 531, and copper foil is used as the current collector layer 5301 of the negative electrode 532. By coating different active material layers 5302 on the current collector layer 5301, the positive electrode 531 and negative electrode 532 for making the core 5 are formed. The current collector layer 5301 of the positive electrode 531 and the current collector layer 5302 of the negative electrode 532 are coated with active material layers 5302. After being wound, 5301 forms the main body of the core 5. The areas on the current collector layer 5301 of the positive electrode 531 coated with active material and the areas on the current collector layer 5301 of the negative electrode 532 not coated with active material are wound to form racetrack-shaped tabs 51 at both ends of the core 5. The tab 51 formed by winding the current collector layer 5301 of the positive electrode 531 is the positive tab 51, and the tab 51 formed by winding the current collector layer 5301 of the negative electrode 532 is the negative tab 51. The positive tab 51 and the negative tab 51 are separate. The positive and negative tabs 51 are located at both ends of the core 5, and their end faces need to be cut flat so that they can fit tightly with the welding plate 31 of the collector plate 3. After the end cap assembly 2 is installed into the housing 1, the positive and negative tabs 51 on the core 5 are respectively attached to the side of the welding plate 31 on the opposite collector plate 3 without the pole knob 32, and are fixedly connected by laser welding. This setting can ensure the reliability of the connection between the core 5 and the collector plate 3 and prevent the connection from breaking when the core 5 moves.

[0061] like Figure 13 and Figure 14As shown, in another embodiment of the present invention, the connection form between the tabs 51 on the core 5 and the collector plate 3 is changed by adjusting the tabs 51. When making the adjustment, the arc area of ​​the racetrack-shaped tabs 51 needs to be cut. The cut area 52 is a fan-shaped area with an angle R2 of 10°-180° or a semi-circular area at the junction of the arc edge and the straight edge. The area after cutting is without tabs 51, while the height of the tabs 51 in the uncut area 52 gradually increases from the outside to the inside. The longitudinal section is trapezoidal. The total height of the tabs 51 is 3-30mm, and the width is 1-10mm. A gap is reserved on the side near the liquid guide rod 4 to avoid contact between the tabs 51 and the liquid guide rod 4. This setting can increase the length of the core 5, so that the tabs 51 can tilt towards the liquid guide rod 4 when connected to the collector plate 3. This not only ensures the contact area at the connection between the tabs 51 and the collector plate 3, but also increases the size of the core 5 and improves the energy density of the core 5.

[0062] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. An end cap assembly for a fast-temperature-controlled lithium-ion battery, characterized in that: The end cap assembly (2) includes a cover plate body (25), an electrode post (21), and a mandrel welding platform (23). The electrode post (21) is disposed through the cover plate body (25) and is insulated from the cover plate body (25). The mandrel welding platform (23) is disposed through the electrode post (21) and is also provided with a mandrel hole (231). The mandrel welding platform (23) is insulated from the electrode post (21).

2. An end cap assembly for a rapidly temperature-controlled lithium-ion battery according to claim 1, characterized in that: An installation groove (211) is provided through the pole post (21), and a splicing ring (213) is provided inside the installation groove (211). A connecting groove (214) is provided on the outer wall of the pole post (21), and the connecting groove (214) is connected end to end and surrounds the pole post (21) once. A plug-in groove (212) is also provided on the pole post (21), and the plug-in groove (212) is connected end to end and surrounds the installation groove (211) once.

3. An end cap assembly for a rapidly temperature-controlled lithium-ion battery according to claim 2, characterized in that: A through groove (251) is provided on the main body (25) of the cover plate, the pole post (21) is located in the through groove (251), and the edge of the through groove (251) is inserted into the connecting groove (214) on the outer wall of the pole post (21).

4. An end cap assembly for a rapidly temperature-controlled lithium-ion battery according to claim 3, characterized in that: A second insulating element (24) and a lower plastic (26) are provided at the joint between the through groove (251) and the connecting groove (214). The lower plastic (26) is annular and located between one inner wall of the connecting groove (214) and one surface of the cover plate body (25). The pole post (21) and the cover plate body (25) are insulated from each other by the second insulating element (24) and the lower plastic (26).

5. An end cap assembly for a rapidly temperature-controlled lithium-ion battery according to claim 2, characterized in that: The outer wall of the mandrel welding platform (23) is provided with a splicing groove (233), and the splicing groove (233) surrounds the mandrel hole (231) for one ring, and the splicing ring (213) is located in the splicing groove (233).

6. An end cap assembly for a rapidly temperature-controlled lithium-ion battery according to claim 5, characterized in that: A first insulating element (22) is provided at the joint between the splicing ring (213) and the splicing groove (233), and at the joint between the outer wall of the mandrel welding platform (23) and the inner wall of the mounting groove (211). The mandrel welding platform (23) and the pole post (21) are insulated from each other by the first insulating element (22).

7. An end cap assembly for a rapidly temperature-controlled lithium-ion battery according to claim 5, characterized in that: A welding shoulder (232) is provided on the inner wall of the mandrel hole (231).

8. An end cap assembly for a rapidly temperature-controlled lithium-ion battery according to claim 1, characterized in that: The thickness T7 of the cover plate body (25) is 1-4mm, the width is 10-200mm, and the length is 10-400mm.

9. An end cap assembly for a fast-temperature-controlled lithium-ion battery according to claim 1, characterized in that: The electrode post (21) is made of aluminum or copper-aluminum composite material, and the thickness of the electrode post (21) is 0.5-3mm and the width is 0.5-10mm.

10. An end cap assembly for a rapidly temperature-controlled lithium-ion battery according to claim 4, characterized in that: The thickness of the lower plastic (26) is 0.2-2mm, and the distance between the lower plastic (26) and the edge of the cover plate body (25) is 0-2mm.

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