Terminal posts, cell covers, and batteries

Abstract

This application relates to an electrode post, a cell cover plate, and a battery, belonging to the field of battery technology. The plate portion of this application is divided into a first plate region and a second plate region along its length, with the thickness of the first plate region being greater than that of the second plate region. The first plate region is close to the cell tab and carries the main current, while the second plate region is adapted to a low current density region. The lower surfaces of both are flush to ensure reliable welding with the tab. The post portion is located above the thicker region, with its axis coinciding with the center line of the plate. Furthermore, the matching of the current path and cross-sectional area is achieved based on the synergistic constraint of the spatial distance ratio A / B and the thickness ratio h1 / h2, significantly balancing the temperature rise and improving battery safety.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to terminals, cell covers, and batteries. Background Technology

[0002] With the iterative development of lithium-ion battery technology, the application scale of power batteries in electric vehicles and energy storage continues to expand, placing higher demands on the performance optimization and safety assurance of battery components. As the core sealing component of lithium-ion batteries, the cell cover plate undertakes multiple functions such as welding with the shell to form a sealed cavity, realizing the conduction of positive and negative electrodes of the electrode group, and providing an assembly carrier. The rationality of its structural design directly affects the overall efficiency of the battery system.

[0003] Traditional cover plates are assembled using a riveting process, and include components such as riveting blocks, upper and lower plastic parts, cylindrical electrode posts, aluminum sheets, and sealing rings. To adapt to lightweight design and high current transmission requirements, the industry has evolved the electrode posts into a racetrack-shaped structure, significantly improving current carrying capacity.

[0004] However, due to the limitations of the battery pack bus welding layout, there is an offset between the center of the existing cover plate pole and the geometric center of the cell. Because the pole base plate adopts a centrally symmetrical design, the current distribution in the base plate area on both sides of the pole center line is significantly unbalanced—the current density in the base plate area closer to the cell pole group is much greater than that on the other side. This asymmetrical current conduction mechanism causes local overheating, which seriously affects the safety performance of the cell. Summary of the Invention

[0005] Therefore, it is necessary to provide a terminal post, cell cover plate, and battery to address the above problems, thereby solving the risk of reduced cell safety performance caused by the high local temperature of the terminal post base plate during the current battery charging and discharging process.

[0006] An electrode post includes a column portion and a plate portion connected to the column portion, wherein the plate portion defines a length direction, a width direction, a thickness direction, and a first central axis S1 in the thickness direction;

[0007] The plate portion includes a first plate region and a second plate region along the length direction. The thickness of the first plate region in the thickness direction is h1, and the thickness of the second plate region in the thickness direction is h2, and h1 > h2.

[0008] The first plate region and the second plate region both include upper and lower end faces that are opposite to each other in the thickness direction, and the lower end face of the first plate region and the lower end face of the second plate region are flush.

[0009] The column portion extends along the thickness direction on the upper end surface of the first plate area, and the central axis of the column portion coincides with the first central axis S1.

[0010] In one embodiment, the projection area of ​​the column portion in the thickness direction is located inside the projection area of ​​the first plate portion in the thickness direction, and there is a distance between the boundaries of the two projection areas.

[0011] In one embodiment, the boundary line between the first plate region and the second plate region is an arc, and the convex direction of the arc is towards the second plate region.

[0012] On the other hand, this application also provides a battery cell cover plate, including a cover plate body, a connecting block, a first insulating element, a second insulating element, a sealing ring, and the aforementioned electrode post; wherein, the cover plate body has a first side end face and a second side end face opposite to each other in the length direction, and the cover plate body is provided with a mounting hole that passes through in the thickness direction, and the mounting hole between the first side end face and the second side end face is located closer to the second side end face;

[0013] The column portion of the pole penetrates the mounting hole; the first plate region is closer to the first side end face of the cover plate body in the length direction than the second plate region; the plate portion is located on one side of the cover plate body in the thickness direction.

[0014] The connecting block is located on the other side of the thickness direction of the cover plate body and is fixedly connected to the column part;

[0015] A first insulating member is arranged around the column portion and extending on the surface of the cover plate body near the connecting block, and the first insulating member is at least partially located between the cover plate body and the connecting block;

[0016] The second insulating member extends around the column portion and on the surface of the cover plate body near the plate portion, and the second insulating member is at least partially located between the cover plate body and the plate portion.

[0017] A sealing ring is arranged around the column portion and at least partially between the cover plate body and the column portion in annular gap.

[0018] In one embodiment, the second insulating member has an end face near the plate portion and an end face away from the plate portion in the thickness direction; wherein, a groove is provided on the end face near the plate portion, the groove has a protrusion, the plate portion is embedded in the groove, and the protrusion in the groove is configured to cooperate with the second plate portion region.

[0019] In one embodiment, the projection area of ​​the column portion in the thickness direction is located inside the projection area of ​​the first plate portion in the thickness direction, and there is a distance between the boundaries of the two projection areas. The sealing ring surrounds the column portion and contacts the first plate portion.

[0020] In one embodiment, the circumferential width of the portion of the sealing ring that contacts the first plate area is d1;

[0021] In the length direction, the distance between the end of the column portion near the second side face and the end of the first plate region near the second side face is d2;

[0022] d1 and d2 satisfy the following relationship:

[0023] 1.2≤d2 / d1≤1.5.

[0024] In one embodiment, the distance between the first central axis and the first side end face of the cover plate body in the length direction is defined as A, and the distance between the first central axis and the second side end face of the cover plate body in the length direction is defined as B, and A > B;

[0025] Distance A, distance B, thickness h1, and thickness h2 together satisfy:

[0026] 0.9≤(A / B) / (h1 / h2)≤1.1.

[0027] On the other hand, this application also provides a battery, comprising:

[0028] The battery casing has a receiving cavity and an open opening;

[0029] A battery cell electrode assembly is placed within the receiving cavity, and the battery cell electrode assembly has a length direction, a width direction, and a thickness direction consistent with the plate body; and

[0030] As described above, a cell cover is arranged at the opening to close the battery casing; wherein the terminals are electrically connected to the cell electrode assembly.

[0031] In one embodiment, the plate portion of the electrode post is electrically connected to the tab of the battery cell electrode assembly.

[0032] The aforementioned electrode post, cell cover plate, and battery, wherein the plate portion of the electrode post is divided into a first plate region and a second plate region with different thicknesses, and the thickness h1 of the first plate region is greater than the thickness h2 of the second plate region; by providing a larger cross-sectional area through the thicker region, the resistance of the high current density region is reduced, thereby reducing Joule heating; the thinner region is adapted to the low current density region, avoiding material redundancy, solving the problem of current distribution imbalance on both sides of the electrode post centerline, and significantly reducing the risk of local overheating;

[0033] This application also has the following advantages:

[0034] (1) The ring width d1 and the distance d2 of this application satisfy 1.2 ≤ d2 / d1 ≤ 1.5. This proportional relationship ensures that the sealing ring forms a stable pressure contact area in the thick area, while avoiding excessive compression.

[0035] (2) This application defines the distance A > B from the first central axis S1 to both sides of the cover plate, and satisfies 0.9 ≤ (A / B) / (h1 / h2) ≤ 1.1, indicating that the current path length is positively correlated with the ratio of conductive cross-sectional area, ensuring that the long path area has a greater current carrying capacity; through mathematical model constraints, the global optimal electrothermal performance is achieved. Attached Figure Description

[0036] Figure 1 This is a three-dimensional structural diagram of the pole of this application.

[0037] Figure 2 This is a top view of the pole of this application.

[0038] Figure 3 This is a schematic diagram of the specific structure of the plate body in this application.

[0039] Figure 4 for Figure 2 Sectional view along direction AA.

[0040] Figure 5 This is an exploded structural diagram of the battery cell cover assembly of this application.

[0041] Figure 6 This is a top view of the battery cell cover plate of this application in its assembled state.

[0042] Figure 7 for Figure 6 BB-direction sectional view.

[0043] Figure 8 This is a schematic diagram of the internal connection structure of the battery in this application.

[0044] Among them: 100, pole post; 200, cover plate body; 300, first insulating component; 400, second insulating component; 500, connecting block; 600, sealing ring; 700, cell electrode assembly; 800, electrode tab;

[0045] 110. Columnar section; 120. Plate section;

[0046] 121. First plate area; 122. Second plate area;

[0047] 200a, First side end face; 200b, Second side end face; 210, Mounting hole;

[0048] S1, First central axis. Detailed Implementation

[0049] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0050] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0051] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0053] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0054] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0055] See Figures 1-4 The diagram shows a schematic diagram of the pole structure in one embodiment of this application.

[0056] The pole post 100 provided in this application includes an integrally formed pole body portion 110 and a plate body portion 120, and a first central axis S1 in the length direction, width direction, thickness direction and thickness direction is defined based on the plate body portion 120.

[0057] In some embodiments, the plate portion 120 is divided into a first plate region 121 and a second plate region 122 along the length direction; wherein: the thickness of the first plate region 121 is h1, the thickness of the second plate region 122 is h2, and h1 > h2.

[0058] In some embodiments, the lower end faces of the first plate region 121 and the second plate region 122 are flush in the thickness direction to ensure the welding flatness with the battery cell tab 800; at the same time, the first plate region 121 and the second plate region 122 are stepped due to the thickness difference.

[0059] In some embodiments, the column portion 110 is fixed to the upper end face of the first plate region 121 and extends along the thickness direction. The column center axis of the column portion 110 coincides with the first center axis S1, and the projection of the column portion 110 in the thickness direction is completely located inside the projection of the first plate region 121.

[0060] In some embodiments, such as Figure 3As shown, the boundary line between the first plate region 121 and the second plate region 122 is an arc, with the arc surface convex toward the second plate region 122.

[0061] The first plate region 121 of this application is arranged on the high current density side, and the resistance is reduced by increasing the cross-sectional area; the second plate region 122 is adapted to the low current density side, so as to achieve material lightweighting and current balance.

[0062] Please continue reading. Figures 5-7 This application also provides a cell cover plate, including a cover plate body 200, a terminal post 100, a connecting block 500, an insulating component, and a sealing ring 600.

[0063] In some embodiments, the cover plate body 200 has a first side end face 200a and a second side end face 200b at both ends in the length direction, and a mounting hole 210 is formed between the first side end face 200a and the second side end face 200b, with the mounting hole 210 being located closer to the second side end face 200b; a column portion 110 passes through the mounting hole 210, and a plate portion 120 is located below the cover plate body 200 in the thickness direction;

[0064] Among them, such as Figure 7 As shown, the post portion 110 of the pole post 100 passes through the mounting hole 210; the first plate region 121 is closer to the first side end face 200a of the cover plate body 200 in the length direction than the second plate region 122; the plate portion 120 is located on one side of the cover plate body 200 in the thickness direction.

[0065] The connecting block 500 is located on the other side of the thickness direction of the cover plate body 200 and is fixedly connected to the column part 110;

[0066] Furthermore, the connecting block 500 is fixed to the top of the column portion 110 for external circuit connection.

[0067] In some embodiments, the first insulating member 300 surrounds the column portion 110 and extends between the upper surface of the cover body 200 and the connecting block 500.

[0068] In some embodiments, the second insulating member 400 surrounds the column portion 110 and extends between the lower surface of the cover plate body 200 and the plate portion 120; a groove is provided on the lower end face in the thickness direction, and a protrusion is provided in the groove; the plate portion 120 is embedded in the groove, and the protrusion abuts against the second plate region 122 to limit the displacement of the thin area.

[0069] In some embodiments, the sealing ring 600 fills the annular gap between the cover plate body 200 and the column portion 110, and presses against the upper end face of the first plate region 121.

[0070] Furthermore, the circumference width of the portion of the sealing ring that contacts the first plate area is defined as d1; in the length direction, the distance between the side end of the column portion 110 near the second side end face 200b and the side end of the first plate area 121 near the second side end face 200b is defined as d2; and d1 and d2 satisfy the relationship: 1.2≤d2 / d1≤1.5, to ensure uniform sealing pressure.

[0071] In some embodiments, the distance from the first central axis S1 to the first side end face 200a of the cover plate is defined as A, and the distance from the first central axis S1 to the second side end face 200b is defined as B, and A > B;

[0072] Meanwhile, the distances A and B, as well as the thicknesses h1 and h2, all satisfy 0.9 ≤ (A / B) / (h1 / h2) ≤ 1.1, which matches the current path length with the conductive cross-sectional area and suppresses local temperature rise.

[0073] Example 1:

[0074] With the center of the pole post (first central axis S1) 200 mm away from the main body of the cover plate, the distances on both sides are A=78 mm and B=38 mm respectively. The thicker part of the pole post base plate, h1=2 mm, is used to achieve different thinning thicknesses. Under the same working conditions, the highest temperature of the pole post with different thinning thicknesses is measured to see if it meets the requirement (≤55℃). The range of values ​​for (A / B) / (h1 / h2) is shown in Table 1.

[0075] Table 1

[0076]

[0077] Example 2:

[0078] With the center of the pole post (first central axis S1) 200 mm away from the main body of the cover plate, the distances on both sides are A=80 mm and B=45 mm respectively. The thicker part of the pole post base plate, h1=2 mm, is used to achieve different thinning thicknesses. Under the same working conditions, the highest temperature of the pole post with different thinning thicknesses is measured to see if it meets the requirement (≤55℃). The range of values ​​for (A / B) / (h1 / h2) is shown in Table 2.

[0079] Table 2

[0080]

[0081] Example 3:

[0082] With the center of the pole post (first central axis S1) 200 mm away from the main body of the cover plate, the distances on both sides are A=68 mm and B=30 mm respectively. The thicker part of the pole post base plate is h1=1.8 mm. Different thinning thicknesses are used. Under the same working conditions, the highest temperature of the pole post with different thinning thicknesses is measured to see if it meets the requirement (≤55℃). The range of values ​​for (A / B) / (h1 / h2) is shown in Table 3.

[0083] Table 3

[0084]

[0085] Analysis of Examples 1 to 3 shows that when (A / B) / (h1 / h2) < 0.9, the thinned portion of the base plate is too thin, resulting in poor current carrying capacity and the electrode temperature does not meet the requirements; when (A / B) / (h1 / h2) > 1.1, the electrode temperature range is gradual, and the increased thickness of the base plate in the thinned area will lead to design redundancy.

[0086] Please continue reading. Figure 8 In other embodiments, this application also provides a battery, comprising:

[0087] The battery casing has a receiving cavity and a top opening;

[0088] The cell electrode assembly 700 is placed inside the receiving cavity, and the electrode tab 800 extends along the length direction;

[0089] Cell cover plate, used to seal the opening of the casing;

[0090] The lower end face of the plate portion 120 is electrically connected to the tab 800. For example, welding can be performed, and the current is transmitted through the first plate portion 121 and the second plate portion 122.

[0091] In summary, the current balancing mechanism of this application has a thickness of h1 in the first plate region 121 and a thickness of h2 in the second plate region 122, with h1 > h2. Through the asymmetric thickness design, the cross-sectional area of ​​the high current density region is increased, thereby reducing Joule heating at its source. In addition, this application defines the distance from the first central axis S1 to the first side end face 200a of the cover plate as A and the distance to the second side end face 200b as B, with A > B. The mathematical model relationship between (A / B) and (h1 / h2) is used to achieve coordinated control of the current path length and cross-sectional area, thereby improving the safety performance of the battery cell.

[0092] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A pole, comprising a columnar portion and a plate portion connected to the columnar portion, characterized in that, The plate body part defines a length direction, a width direction, a thickness direction, and a first central axis in the thickness direction; The plate body part includes a first plate body region and a second plate body region along the length direction, the first plate body region has a thickness of h1 in the thickness direction, the second plate body region has a thickness of h2 in the thickness direction, and h1 > h2; The first plate body region and the second plate body region each include upper and lower end faces opposite in the thickness direction, and the lower end face of the first plate body region and the lower end face of the second plate body region are flush; The column part extends in the thickness direction at the upper end face of the first plate body region, and a column central axis of the column part coincides with the first central axis; And, When the pole column is arranged on the cell cover plate, the distance between the first central axis and the first side end face of the cover plate body in the length direction is defined as A, the distance between the first central axis and the second side end face of the cover plate body in the length direction is defined as B, and A > B; The A, the B, the h1, and the h2 collectively satisfy: 0.9 ≤ (A / B) / (h1 / h2) ≤ 1.1; In the length direction, the tab length between the first central axis and the first side end face is greater than the tab length between the first central axis and the second side end face.

2. The pole according to claim 1, characterized in that The projection area of the column part in the thickness direction is located inside the projection area of the first plate body region in the thickness direction, and there is a distance between the boundaries of the two projection areas.

3. The pole according to claim 1, wherein The boundary between the first plate body region and the second plate body region is an arc, and the convex direction of the arc is toward the second plate body region.

4. An electrode cover plate, characterized by, The cover plate body, the connecting block, the first insulating member, the second insulating member, the sealing ring, and the pole column as claimed in any one of claims 1-3 are included; wherein The cover plate body has first and second side end faces opposite in the length direction, and the cover plate body is provided with a mounting hole penetrating in the thickness direction, and the position of the mounting hole between the first and second side end faces is closer to the second side end face; The column part of the pole column penetrates the mounting hole; the first plate body region is closer to the first side end face of the cover plate body than the second plate body region in the length direction; and the plate body part is located on one side of the cover plate body in the thickness direction; The connecting block is located on the other side of the cover plate body in the thickness direction and is fixedly connected with the column part; The first insulating member surrounds the column part and is arranged to extend on the surface of the cover plate body close to the connecting block, and the first insulating member is at least partially interposed between the cover plate body and the connecting block; The second insulating member surrounds the column part and is arranged to extend on the surface of the cover plate body close to the plate body part, and the second insulating member is at least partially interposed between the cover plate body and the plate body part; The sealing ring surrounds the column part and is at least partially arranged between the cover plate body and the annular gap of the column part.

5. The cell cover plate of claim 4, wherein, The second insulating member has one end face close to the plate body part and the other end face away from the plate body part in the thickness direction. The end surface close to the plate body part is provided with a sink groove, the sink groove has a protrusion, the plate body part is embedded in the sink groove, and the protrusion in the sink groove is configured to cooperate with the second plate body area.

6. The cell cover plate of claim 4 or 5, wherein, The projection area of the column body part in the thickness direction is located inside the projection area of the first plate body area in the thickness direction, and there is a distance between the boundaries of the two projection areas. The sealing ring surrounds the column body part and is in contact with the first plate body area.

7. The cell cover plate according to claim 4 or 5, wherein, The ring width of the contact part of the sealing ring and the first plate body area is d1; In the length direction, the distance between the side end of the column body part close to the second side end surface and the side end of the first plate body area close to the second side end surface is d2; d1 and d2 satisfy the relationship: 1.2≤d2 / d1≤1.

5.

8. A battery, characterized by Comprising: A battery shell having a receiving cavity and an open opening; A cell pole group placed in the receiving cavity, and the cell pole group has a length direction, a width direction and a thickness direction consistent with the plate body part; and The cell cover plate according to any one of claims 4-7 is arranged at the opening to close the battery shell; wherein the pole column is electrically connected with the cell pole group.

9. The battery of claim 8, wherein, The plate body part of the pole column is electrically connected between the pole lug of the cell pole group.

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