Battery cell structure and battery pack

Abstract

The utility model discloses a battery cell structure and a battery pack, and relates to the technical field of batteries. The battery cell structure comprises a shell, a pole group assembly and a cover plate assembly, wherein openings are formed in two opposite ends of the shell; the pole group assembly is arranged in the shell, tab structures are arranged at the two opposite ends of the pole group assembly, each tab structure comprises a connecting part and a transition part, and the size of the transition part in the thickness direction of the pole group assembly is gradually reduced in the direction close to the connecting part; cover plate assemblies are arranged at the two opposite ends of the shell to block the corresponding openings, each cover plate assembly comprises a plastic part, a shaping part is arranged on the side, facing the pole group assembly, of each plastic part, a through hole is formed in each shaping part, the connecting parts penetrate through the through holes of the plastic parts on the corresponding sides, and the shaping parts are configured to abut against the transition parts to shape the transition parts. According to the battery cell structure, the electrical performance of the battery cell structure can be ensured, and the safety of the new energy automobile is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a kind of electric core structure and battery package. BACKGROUND

[0002] With the rapid development of new energy battery technology, the popularity rate of new energy vehicles in the market is also gradually increasing, and the focus of people's attention is mainly on the range of new energy vehicles and the safety of new energy batteries.

[0003] The electric core structure is a power supply structure for new energy vehicles. The electric core structure includes a pole group assembly formed by stacking positive plates and negative plates, and the current is led out by positive tabs and negative tabs. In the prior art, the tabs are connected to the pole after passing through the cover plate, thereby eliminating the structure of the busbar and avoiding the occupation of the space below the cover plate by the pole, thereby saving the space inside the shell of the electric core structure.

[0004] Due to the transition region formed by the foil between the positive tab and the positive plate, and the transition region formed by the foil between the negative tab and the negative plate, the foil at the transition region is in a loose and uncontrolled state, which affects the electrical performance of the electric core structure, and is also prone to protruding and touching the shell, causing short circuit, thereby affecting the safety of the new energy vehicle. SUMMARY

[0005] The utility model aims at providing an electric core structure and battery package that can ensure the electrical performance of the electric core structure and improve the safety of the new energy vehicle.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] An electric core structure includes:

[0008] A shell having openings at opposite ends;

[0009] A pole group assembly disposed in the shell, the pole group assembly having tab structures at opposite ends, the tab structures including a connection portion and a transition portion, the size of the transition portion in the thickness direction of the pole group assembly gradually decreases in the direction close to the connection portion;

[0010] A cover plate assembly is provided at opposite ends of the shell to block the corresponding openings. The cover plate assembly includes a plastic part, and the plastic part has a shaping portion on the side facing the pole group assembly. The shaping portion has a through hole, and the connection portion is disposed in the through hole of the plastic part on the corresponding side. The shaping portion is configured to abut the transition portion to shape the transition portion.

[0011] As an optional solution for the above-mentioned battery cell structure, the shaping portion includes two shaping surfaces that are spaced apart and arranged at an angle, the through hole is located between the two shaping surfaces, the distance between the two shaping surfaces gradually decreases in the direction approaching the through hole, and the shaping surface is configured to press against the surface of the transition portion on one side of the connecting portion.

[0012] As an optional solution to the above-mentioned battery cell structure, the cover plate assembly also includes an end cover and a pole, the plastic part includes a first insulating part and a second insulating part connected to each other, the first insulating part and the second insulating part are respectively located on opposite sides of the end cover, the shaping part is arranged on the second insulating part, the pole is arranged on the end cover and electrically connected to the connecting part, and the first insulating part is located between the pole and the end cover.

[0013] As an optional solution to the above-mentioned battery cell structure, the cover plate assembly also includes a connecting piece, the first insulating part is provided with a connecting groove, the connecting piece is arranged in the connecting groove, and the connecting part passes through the through hole and is bent and electrically connected to the pole through the connecting piece.

[0014] As an optional solution to the above-mentioned battery cell structure, the cover plate assembly further includes a sealing ring, which is sleeved outside the first insulating portion and located between the pole and the end cover to ensure a sealed connection between the pole and the end cover.

[0015] As an optional solution to the above-mentioned battery cell structure, the cover plate assembly further includes a fixing ring, and the fixing ring is configured to fix the pole on the end cover.

[0016] As an optional solution to the above-mentioned battery cell structure, the fixing ring includes a fixing section, a transition section and a pressing section, a flange is protruded from the outer periphery of the pole, the fixing section is fixedly connected to the end cover, and the flange is arranged between the pressing section and the end cover.

[0017] As an optional solution to the above-mentioned battery core structure, the fixing ring is provided with an insulating ring, and the insulating ring can separate the pole and the fixing ring.

[0018] As an optional solution of the above-mentioned battery cell structure, the battery cell structure includes at least two groups of the electrode group components, and the plastic part of each of the cover plate components is provided with the shaping portion and the through hole corresponding to the electrode group components one by one.

[0019] A battery pack comprises a plurality of the battery cell structures described above, wherein the plurality of the battery cell structures are connected in series or in parallel.

[0020] Beneficial effects of the utility model:

[0021] The utility model provides a kind of electric core structure and battery pack.The electric core structure, two groups of cover plate components can be blocked corresponding opening from the opposite ends of shell, to form the closed internal space of shell, both can avoid the overflow of electrolyte, can also play the role of protecting pole group component.Pole lug of pole group component is connected with the through hole of plastic piece, so that the shaping portion can be abutted with transition portion to shape transition portion, and the form of transition portion is in controlled state, avoid bending or protruding transition portion and cause short circuit by touching shell, to ensure the electric performance of electric core structure, improve the safety of new energy automobile. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the front view of the electric core structure provided by the utility model;

[0023] Figure 2 It is Figure 1 the sectional view of A-A in it;

[0024] Figure 3 It is Figure 2 the local enlarged view of B in it;

[0025] Figure 4 It is the explosion view of the electric core structure provided by the utility model;

[0026] Figure 5 It is the front view of the pole group component provided by the utility model;

[0027] Figure 6 It is the first structure schematic view of the plastic piece provided by the utility model;

[0028] Figure 7 It is the second structure schematic view of the plastic piece provided by the utility model.

[0029] In the drawing:

[0030] 1, shell; 11, opening;

[0031] 2, pole group component; 21, pole group body; 22, pole lug structure; 221, connecting portion; 222, transition portion;

[0032] 3, cover plate component; 31, plastic piece; 311, through hole; 312, shaping surface; 313, first insulation part; 314, second insulation part; 315, connecting groove; 32, end cover; 33, pole; 34, connecting sheet; 35, fixing ring; 351, fixed section; 352, transition section; 353, press-fit section; 36, insulation ring; 37, sealing ring;

[0033] 4, protective film;

[0034] 5, side plate. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below, examples of the embodiments are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0036] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0037] Unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" should be understood broadly, for example, it can be fixed connection, or detachable connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] Unless otherwise explicitly specified and limited, "on" or "under" of the first feature to the second feature can include that the first feature and the second feature are in direct contact, or the first feature and the second feature are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" of the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" of the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0039] The technical scheme of the present application is further illustrated below by combining the drawings and through specific embodiments.

[0040] With the rapid development of new energy battery technology, the popularization rate of new energy vehicles in the market is also gradually increasing, and the focus of people's attention is mainly concentrated on the endurance mileage of new energy vehicles and the safety problem of new energy batteries.

[0041] As the power source for new energy vehicles, the battery pack directly impacts their range and safety. The battery pack consists of a housing and multiple battery cells, which are arranged in series or parallel. To maximize the volume utilization within the housing and thus the energy density of the battery pack, the cells are typically arranged in square or blade configurations. Both configurations offer the advantage of being able to be tightly packed, ensuring the maximum possible number of cells can be accommodated within the battery pack.

[0042] In this embodiment, the cell structure is described using a blade cell as an example. This cell structure is characterized by being long and thin. To facilitate electrical connection, the positive and negative electrodes of this cell structure are located at both ends of the cell structure along its length.

[0043] like Figures 1 to 4 As shown, in this embodiment, the battery cell structure includes a shell 1 and an electrode group assembly 2, and the electrode group assembly 2 is arranged in the shell 1. The electrode group assembly 2 includes a electrode group body 21 and electrode ear structures 22 arranged at opposite ends of the electrode group body 21, wherein the electrode group body 21 includes a plurality of positive electrode sheets and a plurality of negative electrode sheets arranged in a stacked manner, and adjacent positive electrode sheets and negative electrode sheets are separated by a diaphragm to prevent short circuit.

[0044] The multiple positive electrode sheets are connected to foils, the distal ends of which are fixed together by ultrasonic welding to form the connection portion 221 of the tab structure 22, and the unwelded portions of the foils form the transition portion 222 of the tab structure 22. Similarly, the multiple negative electrode sheets are connected to foils, the distal ends of which are fixed together by ultrasonic welding to form the connection portion 221 of the tab structure 22, and the unwelded portions of the foils form the transition portion 222 of the tab structure 22. Moreover, the dimension of the transition portion 222 in the thickness direction of the electrode assembly 2 gradually decreases as it approaches the connection portion 221.

[0045] In this embodiment, the cell structure further includes a cover plate assembly 3. Openings 11 are provided at opposite ends of the housing 1, and cover plate assemblies 3 are provided at opposite ends of the housing 1 to seal the corresponding openings 11. In this cell structure, the two sets of cover plate assemblies 3 can seal the corresponding openings 11 at opposite ends of the housing 1, thereby forming a closed internal space in the housing 1, which can prevent electrolyte overflow and protect the electrode assembly 2.

[0046] In this embodiment, one group of cover plate assemblies 3 is provided with an explosion-proof valve, and one group of cover plate assemblies 3 is provided with a liquid injection hole.

[0047] like Figures 3 to 7As shown, the cover plate assembly 3 includes a plastic part 31, which is provided with a through hole 311. The connecting portion 221 is passed through the through hole 311 of the plastic part 31 on the corresponding side and is connected to the corresponding pole 33, thereby eliminating the structure of the busbar and avoiding occupying the space below the plastic part 31, thereby saving space inside the shell 1 of the battery cell structure.

[0048] However, since the foil material of the transition portion 222 is in a loose and uncontrolled state, it will affect the electrical performance of the battery cell structure and is likely to protrude and touch the housing 1 to cause a short circuit, thereby affecting the safety of the new energy vehicle.

[0049] like Figures 3 to 7 As shown, to address the above-mentioned issues, in the battery cell structure provided in this embodiment, a shaping portion is provided on the side of the plastic part 31 facing the electrode assembly 2, and a through hole 311 is provided in the shaping portion. The shaping portion is configured to abut the transition portion 222 to shape the transition portion 222. Because the connection portion 221 of the electrode lug of the electrode assembly 2 is passed through the through hole 311 of the plastic part 31, the shaping portion can abut the transition portion 222 to shape the transition portion 222, keeping the shape of the transition portion 222 in a controlled state, preventing the transition portion 222 from bending or protruding and easily contacting the housing 1 to cause a short circuit, thereby ensuring the electrical performance of the battery cell structure and improving the safety of new energy vehicles.

[0050] like Figure 3 and Figure 7 As shown, the shaping portion includes two shaping surfaces 312 spaced apart from each other. The shaping surfaces 312 are configured to press against the surface of the transition portion 222 located on one side of the connecting portion 221. The through hole 311 is located between the two shaping surfaces 312. Generally speaking, the transition portion 222 is symmetrical about the connecting portion 221. Therefore, the two shaping surfaces 312 on either side of the through hole 311 can respectively shape the portion of the transition portion 222 located on one side of the connecting portion 221, thereby ensuring the shaping effect of the transition portion 222.

[0051] In this embodiment, the two shaping surfaces 312 are arranged at an angle, and the distance between the two shaping surfaces 312 gradually decreases as they approach the through hole 311. The inclination direction of the surface of the transition portion 222 is substantially the same as the inclination direction of the shaping surface 312, so that the shaping surface 312 can shape the transition portion 222 along the direction of the transition portion 222. This allows the transition portion 222 to be shaped while ensuring a small amount of deformation, thereby ensuring a good shaping effect while preventing damage to the transition portion 222 due to excessive deformation.

[0052] like Figure 3 and Figure 4As shown, the cover plate assembly 3 also includes an end cover 32 and a pole 33. The plastic part 31 includes a first insulating portion 313 and a second insulating portion 314 connected to each other. The first insulating portion 313 and the second insulating portion 314 are respectively located on opposite sides of the end cover 32. The shaping portion is arranged on the second insulating portion 314. The pole 33 is arranged on the end cover 32 and is electrically connected to the connecting portion 221. The first insulating portion 313 is located between the pole 33 and the end cover 32.

[0053] The first insulating portion 313 and the second insulating portion 314 can replace the upper and lower plastics of the conventional cover plate assembly 3, saving space and reducing costs. The first insulating portion 313 can separate the pole 33 from the end cap 32, while the second insulating portion 314 can separate the end cap 32 from the pole group body 21, thereby preventing short circuits.

[0054] like Figure 3 and Figure 4 As shown, the cover plate assembly 3 further includes a connecting piece 34. The first insulating portion 313 defines a connecting groove 315. The connecting piece 34 is disposed within the connecting groove 315. The portion of the connecting portion 221 that passes through the through-hole 311 is bent and then electrically connected to the terminal 33 via the connecting piece 34. After the connecting portion 221 passes through the through-hole 311 of the plastic component 31, it is bent toward the connecting piece 34 and welded to the connecting piece 34. The terminal 33 is then secured to the end cap 32 to electrically connect the terminal 33 and the connecting piece 34. This avoids the problem of the connecting portion 221 being blocked by the terminal 33 when directly connecting to the terminal 33, making welding difficult. This reduces assembly difficulty and improves product yield.

[0055] It is worth noting that the connecting piece 34 is provided with a protruding connecting post. When the terminal post 33 is arranged on the end cover 32, it can abut against the connecting post, thereby realizing the electrical connection between the end cover 32 and the connecting piece 34. The depth of the connecting groove 315 is less than or equal to the thickness of the connecting piece 34, so that the connecting portion 221 of the tab structure 22 only needs to be bent once to be attached to the connecting piece 34 for welding, which greatly reduces the possibility of the connecting portion 221 breaking or affecting the electrical performance due to multiple bending.

[0056] like Figure 3 and Figure 4 As shown, the cover plate assembly 3 further includes a fixing ring 35, which is configured to fix the pole 33 to the end cover 32. It is understandable that since the pole 33 needs to be insulated from the end cover 32, it is not possible to directly weld the pole 33 to the end cover 32, so the fixing ring 35 is required for indirect fixation.

[0057] Specifically, the fixing ring 35 includes a fixing section 351, a transition section 352, and a press-fit section 353. A flange is provided on the outer periphery of the pole 33. The fixing section 351 is fixedly connected to the end cover 32, and the flange is disposed between the press-fit section 353 and the end cover 32. Because the fixing ring 35 is fixedly connected to the end cover 32 via the fixing section 351, the press-fit section 353 can press the flange of the pole 33 onto the end cover 32, ensuring that the pole 33 does not separate from the end cover 32.

[0058] It is worth noting that to ensure the reliability of the connection between the fixing ring 35 and the end cap 32, the fixing ring 35 and the end cap 32 are welded together, so it is necessary to ensure insulation between the fixing ring 35 and the pole 33. To achieve this purpose, the fixing ring 35 is covered with an insulating ring 36, which can isolate the pole 33 from the fixing ring 35.

[0059] Furthermore, the insulating ring 36 covers the transition section 352 and the pressing section 353, which can not only ensure that the fixing ring 35 and the pole 33 are insulated and separated, but also reduce the exposed range of the insulating ring 36, thereby further reducing the possibility of direct contact between the pole 33 and the insulating ring 36 or the end cover 32, thereby improving safety.

[0060] In this embodiment, the cover plate assembly 3 also includes a sealing ring 37, which is positioned outside the first insulating portion 313 and between the terminal post 33 and the end cap 32 to provide a sealed connection between the terminal post 33 and the end cap 32. The sealing ring 37 seals the gap between the end cap 32 and the terminal post 33 to prevent electrolyte overflow and ensure the safety of the battery cell structure. It is worth noting that while the plastic component 31 can provide a certain degree of sealing, its relatively high hardness results in poor sealing performance, whereas the sealing ring 37 ensures a sufficient seal.

[0061] To increase the battery cell's power output, the cell structure includes at least two electrode assembly assemblies 2. Each cover assembly 3's plastic component 31 is provided with a shaping portion and through-hole 311 corresponding to each electrode assembly 2. Multiple electrode assembly assemblies 2 can increase power output. Compared to the increased thickness of a single electrode assembly 2, multiple electrode assembly assemblies 2 can reduce the difficulty of lamination, improve product yield, and reduce costs. The plastic component 31 of the cover assembly 3 shapes the transition portion 222 of the tab structure 22 of the corresponding multiple electrode assembly assemblies 2, thereby ensuring the cell's electrical performance.

[0062] like Figure 2 and Figure 5 As shown, in this embodiment, the cell structure includes two electrode group assemblies 2. The plastic part 31 of each cover plate assembly 3 is provided with two shaped portions, each of which is provided with a through hole 311. The connecting portions 221 of the two electrode group assemblies 2 are bent toward the connecting piece 34 after passing through the corresponding through holes 311 and are welded to the connecting piece 34, resulting in a simple structure and high reliability.

[0063] In this embodiment, a protective film 4 is provided on the outside of the electrode assembly 2. The protective film 4 enables the positive electrode sheet and the negative electrode sheet to be stacked more tightly together, protects the electrode sheets, and prevents the electrode sheets from contacting the housing 1 and causing short circuits or leakage. It is worth noting that if the battery cell structure includes multiple electrode assembly assemblies 2, the protective film 4 can be provided on the outside of each electrode assembly 2, or all electrode assembly assemblies 2 can be provided with the protective film 4.

[0064] In this embodiment, the cell structure also includes side panels 5, which are disposed within the housing 1 and located between the electrode assembly 2 and the housing 1. The side panels 5 separate the electrode assembly 2 from the housing 1, providing support and protection for the electrode assembly 2 while also preventing direct contact between the electrode assembly and the housing 1, which could cause deformation and affect electrical performance. It is worth noting that the side panels 5 can be located either between the electrode assembly 2 and the protective film 4 or between the protective film 4 and the housing 1.

[0065] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, according to the concept of the present invention, there may be changes in the specific implementation methods and application scope. The content of this specification should not be understood as limiting the present invention.

Claims

1. A battery cell structure, characterized in that: include: A housing (1), wherein openings (11) are provided at opposite ends of the housing (1); A pole group assembly (2) is arranged in the housing (1), and pole ear structures (22) are provided at opposite ends of the pole group assembly (2), the pole ear structure (22) comprising a connecting portion (221) and a transition portion (222), wherein the dimension of the transition portion (222) in the thickness direction of the pole group assembly (2) gradually decreases in a direction approaching the connecting portion (221); A cover plate assembly (3) is provided at opposite ends of the shell (1) to block the corresponding opening (11), the cover plate assembly (3) comprises a plastic part (31), a shaping portion is provided on a side of the plastic part (31) facing the pole group assembly (2), a through hole (311) is provided in the shaping portion, the connecting portion (221) is passed through the through hole (311) of the plastic part (31) on the corresponding side, and the shaping portion is configured to abut the transition portion (222) to shape the transition portion (222).

2. The battery cell structure according to claim 1, characterized in that: The shaping portion comprises two shaping surfaces (312) spaced apart and arranged at an angle, the through hole (311) is located between the two shaping surfaces (312), the distance between the two shaping surfaces (312) gradually decreases in a direction approaching the through hole (311), and the shaping surface (312) is configured to press against a surface of the transition portion (222) located on one side of the connecting portion (221).

3. The battery core structure according to claim 1, characterized in that: The cover plate assembly (3) further includes an end cover (32) and a pole (33); the plastic part (31) includes a first insulating portion (313) and a second insulating portion (314) connected to each other; the first insulating portion (313) and the second insulating portion (314) are respectively located on opposite sides of the end cover (32); the shaping portion is arranged on the second insulating portion (314); the pole (33) is arranged on the end cover (32) and electrically connected to the connecting portion (221); the first insulating portion (313) is located between the pole (33) and the end cover (32).

4. The battery core structure according to claim 3, characterized in that: The cover plate assembly (3) further includes a connecting piece (34); the first insulating portion (313) is provided with a connecting groove (315); the connecting piece (34) is arranged in the connecting groove (315); the connecting portion (221) passes through the through hole (311) and is partially bent and then electrically connected to the pole (33) through the connecting piece (34).

5. The battery core structure according to claim 3, characterized in that: The cover plate assembly (3) further comprises a fixing ring (35), wherein the fixing ring (35) is configured to fix the pole (33) to the end cover (32).

6. The battery core structure according to claim 5, characterized in that: The fixing ring (35) comprises a fixing section (351), a transition section (352) and a pressing section (353); a flange is provided on the outer periphery of the pole (33); the fixing section (351) is fixedly connected to the end cover (32); and the flange is provided between the pressing section (353) and the end cover (32).

7. The battery core structure according to claim 6, characterized in that: The fixing ring (35) is sleeved with an insulating ring (36), and the insulating ring (36) can separate the pole (33) and the fixing ring (35).

8. The battery cell structure according to any one of claims 1 to 7, characterized in that: The battery core structure comprises at least two groups of the electrode group components (2), and the plastic part (31) of each of the cover plate components (3) is provided with the shaping portion and the through hole (311) corresponding one-to-one to the electrode group components (2).

9. The battery cell structure according to any one of claims 1 to 7, characterized in that: The battery core structure further comprises a side plate (5), wherein the side plate (5) is arranged in the shell (1), and the side plate (5) is located between the pole group assembly (2) and the shell (1).

10. A battery pack, characterized in that: The battery pack includes a plurality of battery cell structures according to any one of claims 1 to 9, and the plurality of battery cell structures are connected in series or in parallel.

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