Battery cell cover plate assembly and battery cell

Abstract

The application relates to the battery technical field and discloses a battery cell cover plate assembly and a battery cell. The battery cell cover plate assembly comprises a cover plate, a lower plastic on the lower surface of the cover plate, a pole column comprising a pole column bottom plate and a pole column body, the pole column body is eccentrically arranged on the pole column bottom plate along an X direction, and the pole column body is centrally arranged on the pole column bottom plate along a Y direction; the pole column body sequentially penetrates through the lower plastic and the cover plate, the pole column bottom plate is provided with an annular groove surrounding the pole column body, the annular groove is provided with a pair of first groove sections oppositely arranged along the Y direction and second groove sections and third groove sections oppositely arranged along the X direction, the groove depth h of the first groove section corresponding to the lower end of the pole column body is the deepest part of the first groove section, the groove depth of the second groove section is h1, the groove depth of the third groove section is h2, h > h1 > h2; and a sealing ring is clamped between the lower plastic and the pole column bottom plate and seals the gap between the lower plastic and the pole column bottom plate. The application can improve the sealing performance between the pole column bottom plate and the lower plastic.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to a cell cover assembly and a cell. Background Technology

[0002] A terminal is a conductive component in a battery cell used to realize electrical energy input / output and to build an electrical connection between the battery cell and external circuits. One end of the terminal is connected to the tab inside the battery cell to conduct current, and the other end is exposed outside the battery cell shell to cooperate with external conductive structures such as connectors, busbars, and tabs.

[0003] Specifically, a terminal post typically consists of a terminal post body and a terminal post base plate. The end of the terminal post body furthest from the base plate is used to engage with an external conductive structure, while the base plate is located inside the cell casing and is used to connect with the tabs. Depending on the structural layout design of the cell, the positional relationship between the terminal post body and the base plate is mainly divided into two categories: one is concentric arrangement; the other is eccentric arrangement. However, when the terminal post adopts an eccentric arrangement, the base plate is prone to uneven stress during the assembly of the cell cover assembly, which can lead to warping and deformation. This, in turn, reduces the adhesion between the base plate and the lower plastic in the cell cover assembly, affecting the sealing effect after assembly. Summary of the Invention

[0004] This invention provides a cell cover assembly and a cell to solve the problem that when the terminals are arranged eccentrically, the terminal base plate is prone to warping during the assembly of the cell cover assembly, which reduces the fit between the terminal base plate and the lower plastic and thus affects the sealing reliability.

[0005] In a first aspect, the present invention provides a battery cell cover assembly, comprising:

[0006] Cover plate;

[0007] The lower plastic, along the Z direction, is located on the lower surface of the cover plate;

[0008] An electrode post includes an electrode post base plate and an electrode post body disposed on the upper surface of the electrode post base plate along the Z direction. Along the X direction, the electrode post body is eccentrically disposed on the electrode post base plate, and along the Y direction, the electrode post body is centrally disposed on the electrode post base plate. The electrode post body passes sequentially through the lower plastic and the cover plate along the Z direction, with at least a portion of the lower plastic sandwiched between the electrode post base plate and the cover plate. The electrode post base plate has an annular groove surrounding the electrode post body. The annular groove has a pair of first groove segments disposed opposite each other along the Y direction and a second and third groove segments disposed opposite each other along the X direction. Along the X direction, the distance between the second groove segment and the adjacent sidewall of the electrode post body is less than the distance between the third groove segment and the adjacent sidewall of the electrode post body. Along the Y direction, the groove depth h of the portion of the first groove segment corresponding to the lower end of the electrode post body is greater than the groove depth of other areas of the first groove segment. Along the Z direction, the groove depth of the second groove segment is h1, and the groove depth of the third groove segment is h2, where h > h1 > h2.

[0009] A sealing ring is sandwiched between the lower plastic and the pole base plate. Along the Z direction, the bottom surface of the sealing ring is in contact with the bottom surface of the annular groove, and a portion of the sealing ring protrudes from the annular groove.

[0010] Beneficial Effects: For electrode posts eccentrically positioned in the X direction on the electrode post base plate, this invention addresses this issue by creating an annular groove on the side of the electrode post base plate facing the lower plastic. This annular groove is designed with a pair of first groove segments positioned opposite each other in the Y direction and a second and third groove segment positioned opposite each other in the X direction. Simultaneously, the groove depth h of the first groove segment corresponding to the lower end of the electrode post body is greater than the groove depth h1 of the second groove segment, and the groove depth h1 of the second groove segment is greater than the groove depth h2 of the third groove segment. Combined with a sealing ring that fits snugly against the bottom surface of the annular groove and is partially exposed, the adaptable deformation of the sealing ring can offset the non-uniform warping of the electrode post base plate during cell assembly caused by the eccentric positioning of the electrode post body. This effectively eliminates the gap between the electrode post base plate and the lower plastic, improving the sealing fit and connection reliability, preventing safety hazards such as leakage and short circuits due to sealing failure, and thus ensuring the structural stability and long-term safety of the cell.

[0011] In one optional embodiment, the first groove segment includes an intermediate groove segment, a first transition groove segment, and a second transition groove segment. One end of the intermediate groove segment is connected to the second groove segment through the first transition groove segment, and the other end is connected to the third groove segment through the second transition groove segment. The intermediate groove segment corresponds to the lower end of the pole body, and the groove depth of the intermediate groove segment is h. Along the direction away from the intermediate groove segment, the groove depths of the first transition groove segment and the second transition groove segment gradually decrease. The maximum groove depth of the first transition groove segment and the second transition groove segment is equal to the groove depth h of the intermediate groove segment, the minimum groove depth of the first transition groove segment is equal to the groove depth h1 of the second groove segment, and the minimum groove depth of the second transition groove segment is equal to the groove depth h2 of the third groove segment.

[0012] Beneficial Effects: This invention further subdivides the first groove segment into an intermediate groove segment, a first transition groove segment, and a second transition groove segment. Leveraging the strong structural strength of the base plate near the pole body, the intermediate groove segment is designed with a uniform depth. This simplifies the processing and forming of the intermediate groove segment, reduces manufacturing costs, and ensures that the sealing ring within the intermediate groove segment receives uniform and stable compressive force, avoiding localized overload or insufficient sealing pressure caused by uneven groove depth. Simultaneously, along the direction away from the intermediate groove segment, the groove depths of the first and second transition groove segments gradually decrease, and their maximum groove depth is the same as that of the intermediate groove segment. The groove depth h is consistent with the first transition groove and the second transition groove. The minimum groove depth of the first transition groove and the second transition groove are matched with the groove depth h1 of the second groove and the groove depth h2 of the third groove, respectively. With the smooth transition design between each groove, stress concentration at the corner of the groove is eliminated, the structural durability of the plastic parts is improved, and the compression of the sealing ring is distributed in a continuous and gradual manner along the extension direction of the groove. This is highly compatible with the asymmetrical arrangement of the pole posts and the strength distribution characteristics of the base plate structure. On the basis of forming a reliable seal in the core sealing area, the sealing effectiveness of the edge area is also taken into account, which significantly improves the sealing reliability and structural stability of the cell cover assembly and extends its service life.

[0013] In one alternative implementation, along the Y direction, the orthographic projection of the lower end of the pole body toward the intermediate groove segment falls within the range of the intermediate groove segment.

[0014] Beneficial effects: By limiting the orthographic projection of the lower end of the electrode body towards the middle groove section along the Y direction to fall within the groove section, this invention enables the stress generated by the eccentric arrangement of the electrode body to concentrate on the first groove section area with a greater groove depth. This achieves a match between the stress and the groove depth adaptation area, effectively avoiding local stress accumulation caused by the misalignment of the stress application location and the groove structure. It further suppresses the warping deformation of the electrode base plate away from the electrode body, improves the tightness of the fit between the electrode base plate and the lower plastic, and ensures the stable positioning and sealing performance of the sealing ring in the annular groove. This enhances the sealing reliability of the cell cover assembly, avoids cell safety hazards caused by sealing failure, and extends the service life of the cell.

[0015] In one optional implementation, along the X direction, the orthographic projection width of the lower end of the pole body on the XY plane is W, and the orthographic projection length of the intermediate groove segment on the XY plane is M, satisfying W≤M≤W+2mm.

[0016] Beneficial effects: Along the X direction, this invention limits the relationship between the orthographic projection width W of the lower end of the electrode body on the XY plane and the orthographic projection length M of the intermediate groove segment to W≤M≤W+2mm. On the one hand, this ensures that the coverage area of ​​the intermediate groove segment corresponds to the projection area of ​​the electrode body. Relying on the strong structural strength of the electrode base plate near the electrode body, it ensures that the sealing ring in the intermediate groove segment can form a targeted seal at the contact area between the electrode and the plastic part, strengthening the sealing reliability of the core area. On the other hand, controlling the upper limit of the intermediate groove segment length within the reasonable range of W+2mm avoids excessive weakening of the structural strength of the electrode base plate due to an excessively long intermediate groove segment, preventing the electrode base plate from warping or deforming during assembly or battery cell charge-discharge cycles. It also avoids redundant material consumption, balancing structural stability and production cost optimization. In addition, this dimensional constraint, together with the segmented gradual groove depth and the quantitative design of the sealing ring compression rate, forms a synergy, making the sealing pressure distribution highly compatible with the structural strength distribution of the electrode base plate, further improving the overall sealing performance and service life of the battery cell cover assembly.

[0017] In one optional embodiment, the lower end of the pole body is projected onto the XY plane in a circular shape with a diameter of d. The relationship between h, h1, and d satisfies: h1 = h - (K1 - d / 2) × 0.01, where K1 is the distance between the outer wall of the second groove segment and the adjacent sidewall of the pole body along the X direction, and K1 > d / 2; the relationship between h, h2, and d satisfies: h2 = h - (K2 - d / 2) × 0.01, where K2 is the distance between the outer wall of the third groove segment and the adjacent sidewall of the pole body along the X direction, and K2 > d / 2.

[0018] Beneficial effects: This invention defines the orthographic projection shape of the lower end of the electrode body on the XY plane as circular, and establishes quantitative relationships between h1 and h, K1, d, and h2 and h, K2, d. Combined with the constraints of K1 > d / 2 and K2 > d / 2, a gap is left between the annular groove and the electrode body, which can avoid weakening the structural strength of the electrode base plate due to the groove structure being too close to the electrode body. At the same time, this quantitative design allows the compression of the sealing ring to be regularly regulated according to the distance between the groove and the electrode body. Combined with the strong structural strength of the electrode base plate near the electrode body, it avoids the risk of aging and damage of the sealing ring caused by local overpressure or electrolyte leakage caused by underpressure. It also makes the sealing pressure distribution highly consistent with the stress characteristics of the asymmetrical arrangement of the electrodes and the structural strength distribution of the electrode base plate, thereby improving the sealing performance and service life of the cell cover assembly.

[0019] In one optional embodiment, along the Z direction, the thickness of the sealing ring is H, and the groove depth h of the intermediate groove segment, the groove depth h1 of the second groove segment, and the groove depth h2 of the third groove segment are all less than H, and H satisfies the following relationships with h, h1, and h2 respectively: 20%≤[(Hh) / H]×100%≤45%; 20%≤[(H-h1) / H]×100%≤45%; 20%≤[(H-h2) / H]×100%≤45%.

[0020] Beneficial effects: By limiting the groove depth h of the intermediate groove, the groove depth h1 of the second groove, and the groove depth h2 of the third groove to be less than the thickness H of the sealing ring, and controlling 20%≤[(Hh) / H]×100%≤45%; 20%≤[(H-h1) / H]×100%≤45%; 20%≤[(H-h2) / H]×100%≤45%, this invention ensures that the sealing ring forms a moderate and uniform compression deformation after assembly. This avoids the risk of poor sealing surface contact and electrolyte leakage due to excessively low compression ratio, while also preventing stress fatigue and aging of the sealing ring caused by excessively high compression ratio. This accelerates the process, thereby extending the service life of the sealing ring. On the other hand, the quantitative design of this compression rate range is compatible with the design of the annular groove opening and the reserved gap in the electrode body to ensure the structural strength of the electrode base plate. This allows the sealing pressure of the sealing ring to match the load-bearing capacity of the electrode base plate, avoiding deformation of the electrode base plate due to excessive sealing pressure. At the same time, the segmented and gradually changing groove depth structure of the groove enables the orderly distribution of sealing pressure in the core area and the edge area, further improving the sealing reliability and structural stability of the cell cover assembly, and ensuring its performance consistency during cell charging and discharging cycles and long-term use.

[0021] In one optional embodiment, along the Z direction, the thickness of the pole base plate is T, and the value range of the pole base plate thickness T is 1.2mm≤T≤3mm, and / or, the relationship between the groove depth h of the intermediate groove section and the thickness T of the pole base plate satisfies 0.4≤h / T≤1.2.

[0022] Beneficial effects: This invention limits the thickness of the electrode base plate to a range of 1.2mm ≤ T ≤ 3mm, ensuring sufficient structural strength to effectively resist external forces and stress impacts during cell assembly and charge / discharge cycles, preventing failures such as warping and deformation. It also avoids redundancy in the overall component volume due to excessive electrode base plate thickness, while still meeting the energy density requirements of the battery cell. Furthermore, by establishing a ratio of 0.4 ≤ h / T ≤ 1.2 between the groove depth h and the electrode base plate thickness T, matching the groove depth with the electrode base plate thickness is achieved. When h / T is in the lower limit range, it prevents excessive groove depth from weakening the base plate's structural strength. When h / T is in the upper limit range, it provides sufficient compression space for the sealing ring to ensure sealing performance. Combined with the aforementioned segmented structure of the annular groove and the quantitative design of the sealing ring compression ratio, a synergistic optimization of structural strength and sealing performance is achieved, further improving the reliability and service life of the battery cell cover assembly.

[0023] In one optional embodiment, the annular groove extends in the same direction as the circumference of the pole base plate, and the distance between the orthographic projection edge of the annular groove and the orthographic projection edge of the pole base plate is equal everywhere in the XY plane.

[0024] Beneficial Effects: This invention, by setting the annular groove to extend in the same direction as the circumference of the electrode base plate, and ensuring that the distance between the orthographic projection edge of the annular groove and the orthographic projection edge of the electrode base plate is equal everywhere on the XY plane, achieves two main benefits. First, it creates a regular annular layout that fits the electrode base plate. Combined with the gradual change in groove depth and quantitative design, this ensures a uniform and orderly distribution of the compression pressure of the sealing ring, guaranteeing consistent circumferential sealing between the electrode base plate and the plastic component, effectively eliminating the risk of electrolyte leakage caused by weak points in the local seal. Second, this equal-spacing design prevents the groove from getting too close to the edge of the electrode base plate, thus avoiding weakening the structural strength of the base plate edge. This ensures that the load-bearing capacity of the electrode base plate is balanced at all circumferential positions, preventing deformation or cracking of the base plate due to localized stress concentration. Simultaneously, the regular annular equal-spacing structure facilitates standardized processing and molding of the mold, reducing dimensional deviations during production, improving the mass production consistency and yield rate of the battery cell cover assembly. This, combined with the aforementioned segmented groove structure and sealing ring compression rate control, further optimizes the sealing reliability and structural stability of the assembly.

[0025] In one alternative embodiment, a gap is left between the opening of the annular groove and the outer wall of the pole body in the XY plane.

[0026] Beneficial effects: This invention, by leaving a gap between the opening of the annular groove and the outer wall of the electrode body on the XY plane, and combining this with the differentiated design where the distance between the second groove segment and the electrode body along the X direction is smaller than that of the third groove segment, and the groove depth h1 of the second groove segment is greater than that of the third groove segment, can adapt to the stress distribution pattern caused by the eccentric arrangement of the electrode, specifically disperse the stress concentration in different areas, further prevent the electrode base plate from warping due to uneven stress, improve the tightness of the seal ring, the annular groove, and the lower plastic, thereby enhancing the sealing reliability and structural stability of the cell cover assembly and ensuring the long-term safe use of the cell.

[0027] Secondly, the present invention also provides a battery cell, comprising:

[0028] The shell has an opening;

[0029] In the aforementioned cell cover assembly, the cover is disposed over the opening, and the lower plastic and the electrode base plate are located inside the housing.

[0030] Beneficial effects: The battery cell of the present invention includes the battery cell cover assembly as described above, and has all the beneficial technical effects of the battery cell cover assembly, which will not be repeated here. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of a battery cell cover assembly according to an embodiment of the present invention;

[0033] Figure 2 for Figure 1 An exploded view of the battery cell cover assembly shown.

[0034] Figure 3 for Figure 1 The cell cover assembly shown is a cross-sectional view from the AA perspective;

[0035] Figure 4 for Figure 1 The cell cover assembly shown is a cross-sectional view from the BB perspective;

[0036] Figure 5 for Figure 1 The cell cover assembly shown is a cross-sectional view from the CC perspective.

[0037] Figure 6 for Figure 1 Schematic diagram of the structure of the central pole;

[0038] Figure 7 for Figure 6 The pole shown is a cross-sectional view from the DD perspective;

[0039] Figure 8 for Figure 6 The pole shown is a cross-sectional view from the EE perspective;

[0040] Figure 9 for Figure 6 The pole shown is a cross-sectional view from the FF perspective.

[0041] Explanation of reference numerals in the attached figures:

[0042] 1. Cover plate; 2. Lower plastic; 3. Terminal post; 301. Terminal post base plate; 302. Terminal post body; 4. Annular groove; 401. First groove section; 4011. Middle groove section; 4012. First transition groove section; 4013. Second transition groove section; 402. Second groove section; 403. Third groove section; 5. Sealing ring. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] The following is combined Figures 1 to 9 The embodiments of the present invention are described below. For ease of description thereafter, as follows... Figure 2 As shown, a spatial rectangular coordinate system is established: the height direction (or thickness direction) of the pole base plate 301 is denoted as the Z direction, the length direction of the pole base plate 301 is denoted as the X direction, and the width direction of the pole base plate 301 is denoted as the Y direction.

[0045] According to an embodiment of the present invention, in one aspect, Figures 1 to 9 As shown, a battery cell cover assembly is provided, including: a cover plate 1, a lower plastic 2, an electrode post 3, and a sealing ring 5.

[0046] Specifically, along the Z direction, the lower plastic 2 is located on the lower surface of the cover plate 1; the pole 3 includes a pole base plate 301 and a pole body 302 disposed on the upper surface of the pole base plate 301 along the Z direction, the pole body 302 is eccentrically disposed on the pole base plate 301 along the X direction, and the pole body 302 is centrally disposed on the pole base plate 301 along the Y direction; the pole body 302 passes through the lower plastic 2 and the cover plate 1 sequentially along the Z direction, and at least a portion of the lower plastic 2 is sandwiched between the pole base plate 301 and the cover plate 1; the pole base plate 301 is provided with an annular groove 4 surrounding the pole body 302, the annular groove 4 having a pair of first groove segments 401 disposed opposite each other along the Y direction and a pair of second groove segments 401 disposed opposite each other along the X direction. In the X direction, the distance between the second groove section 402 and the adjacent sidewall of the pole body 302 is less than the distance between the third groove section 403 and the adjacent sidewall of the pole body 302. In the Y direction, the groove depth h of the corresponding part of the first groove section 401 and the lower end of the pole body 302 is greater than the groove depth of other areas of the first groove section 401. In the Z direction, the groove depth of the second groove section 402 is h1, and the groove depth of the third groove section 403 is h2, where h > h1 > h2. The sealing ring 5 is sandwiched between the lower plastic 2 and the pole base plate 301. In the Z direction, the bottom surface of the sealing ring 5 is in contact with the bottom surface of the annular groove 4, and part of the sealing ring 5 is exposed outside the annular groove 4.

[0047] For the electrode post 3 eccentrically positioned on the electrode post base plate 301 in the X direction on the electrode post body 302, this embodiment provides an annular groove 4 on the side of the electrode post base plate 301 facing the lower plastic 2. This annular groove 4 is designed with a structure having a pair of first groove segments 401 arranged opposite each other in the Y direction and a second groove segment 402 and a third groove segment 403 arranged opposite each other in the X direction. Simultaneously, the groove depth h of the portion of the first groove segment 401 corresponding to the lower end of the electrode post body 302 is greater than the groove depth h1 of the second groove segment 402, and the groove depth h1 of the second groove segment 402 is greater than... At the groove depth h2 of the third groove section 403, a sealing ring 5 that fits against the bottom surface of the annular groove 4 and is partially exposed can be used to offset the non-uniform warping of the electrode base plate 301 during the assembly of the battery cell assembly due to the eccentric setting of the electrode body 302. This effectively eliminates the gap between the electrode base plate 301 and the lower plastic 2, improves the sealing fit and connection reliability of the two, avoids safety hazards such as leakage and short circuit due to sealing failure of the battery cell, and thus ensures the structural stability and long-term safety of the battery cell.

[0048] In one embodiment, such as Figure 6 and Figure 9As shown, the first groove segment 401 includes an intermediate groove segment 4011, a first transition groove segment 4012, and a second transition groove segment 4013. One end of the intermediate groove segment 4011 is connected to the second groove segment 402 through the first transition groove segment 4012, and the other end is connected to the third groove segment 403 through the second transition groove segment 4013. The intermediate groove segment 4011 corresponds to the lower end of the pole body 302, and the groove depth of the intermediate groove segment 4011 is h. Along the direction away from the intermediate groove segment 4011, the groove depths of the first transition groove segment 4012 and the second transition groove segment 4013 gradually decrease. The maximum groove depth of the first transition groove segment 4012 and the second transition groove segment 4013 is equal to the groove depth h of the intermediate groove segment 4011. The minimum groove depth of the first transition groove segment 4012 is equal to the groove depth h1 of the second groove segment 402. The minimum groove depth of the second transition groove segment 4013 is equal to the groove depth h2 of the third groove segment 403.

[0049] In this embodiment, the first groove segment 401 is further subdivided into an intermediate groove segment 4011, a first transition groove segment 4012, and a second transition groove segment 4013. Utilizing the strong structural strength of the pole post base plate 301 near the pole post body 302, the intermediate groove segment 4011 is designed with a uniform depth. This simplifies the processing and forming of the intermediate groove segment 4011, reduces manufacturing costs, and ensures that the sealing ring 5 within the intermediate groove segment 4011 receives uniform and stable compressive force, avoiding localized overload or insufficient sealing pressure issues caused by uneven groove depth. Simultaneously, the groove depths of the first transition groove segment 4012 and the second transition groove segment 4013 gradually decrease along the direction away from the intermediate groove segment 4011. Furthermore, its maximum groove depth is consistent with the groove depth h of the middle groove section 4011. The minimum groove depths of the first transition groove section 4012 and the second transition groove section 4013 are matched with the groove depth h1 of the second groove section 402 and the groove depth h2 of the third groove section 403, respectively. With the smooth transition design between each groove, stress concentration at the corner of the groove is eliminated, the structural durability of the plastic parts is improved, and the compression of the sealing ring 5 forms a continuous and gradual distribution along the extension direction of the groove. This is highly compatible with the asymmetrical arrangement of the pole post 3 and the strength distribution characteristics of the base plate structure. On the basis of forming a reliable seal in the core sealing area, the sealing effectiveness of the edge area is also taken into account, which significantly improves the sealing reliability and structural stability of the cell cover assembly and extends its service life.

[0050] Furthermore, such as Figure 6 and Figure 9As shown, along the Y direction, the orthographic projection of the lower end of the pole body 302 toward the intermediate groove section 4011 falls within the range of the intermediate groove section 4011. It can be understood that by limiting the orthographic projection of the lower end of the pole body 302 toward the intermediate groove section 4011 along the Y direction to fall within this groove section range, this embodiment enables the stress generated by the eccentric arrangement of the pole body 302 to concentrate on the area of ​​the first groove section 401 with a greater groove depth. This achieves a match between the stress and the groove depth adaptation area, effectively avoiding local stress accumulation caused by misalignment between the stress application location and the groove structure. It further suppresses the warping deformation of the pole base plate 301 away from the pole body 302, improves the tightness of the fit between the pole base plate 301 and the lower plastic 2, and ensures the stable positioning and sealing performance of the sealing ring 5 within the annular groove 4. This strengthens the sealing reliability of the cell cover assembly, avoids cell safety hazards caused by sealing failure, and extends the service life of the cell.

[0051] Furthermore, such as Figure 7 and Figure 9 As shown, along the X direction, the orthographic projection width of the lower end of the pole body 302 on the XY plane is W, and the orthographic projection length of the intermediate groove segment 4011 on the XY plane is M, satisfying W≤M≤W+2mm. It can be understood that, along the X direction, this embodiment limits the relationship between the orthographic projection width W of the lower end of the pole body 302 on the XY plane and the orthographic projection length M of the intermediate groove segment 4011 to W≤M≤W+2mm. On one hand, this ensures that the coverage area of ​​the intermediate groove segment 4011 corresponds to the projection area of ​​the pole body 302. Relying on the strong structural strength of the pole base plate 301 near the pole body 302, it ensures that the sealing ring 5 within the intermediate groove segment 4011 can form a targeted seal at the contact point between the pole 3 and the plastic part, strengthening the sealing reliability of the core area. On the other hand, the intermediate groove segment 401... The upper limit of the length is controlled within a reasonable range of W+2mm to avoid excessive weakening of the structural strength of the electrode base plate 301 due to excessive length of the middle groove section 4011. This prevents the electrode base plate 301 from warping or deforming during assembly or battery cell charge-discharge cycles, while also avoiding redundant material consumption and balancing structural stability with production cost optimization. In addition, this dimensional constraint, together with the segmented gradual groove depth of the groove and the quantitative design of the compression ratio of the sealing ring 5, forms a synergy, making the sealing pressure distribution highly compatible with the structural strength distribution of the electrode base plate 301, further improving the overall sealing performance and service life of the battery cell cover assembly.

[0052] In one embodiment, such as Figure 7 and Figure 9As shown, in the XY plane, a gap is left between the opening of the annular groove 4 and the outer wall of the electrode body 302. This embodiment, by leaving a gap between the opening of the annular groove 4 and the outer wall of the electrode body 302 in the XY plane, and combining this with the differentiated design where the distance between the second groove segment 402 and the electrode body 302 along the X direction is smaller than that of the third groove segment 403, and the groove depth h1 of the second groove segment 402 is greater than the groove depth h2 of the third groove segment 403, can adapt to the stress distribution pattern caused by the eccentric arrangement of the electrode 3. This specifically disperses the stress concentration in different areas, further preventing the electrode base plate 301 from warping due to uneven stress, improving the tightness of the fit between the sealing ring 5 and the annular groove 4 and the lower plastic 2, thereby enhancing the sealing reliability and structural stability of the cell cover assembly and ensuring the long-term safe use of the cell.

[0053] In one embodiment, such as Figure 7 and Figure 9 As shown, the lower end of the pole body 302 is projected onto the XY plane in a circular shape with a diameter of d. The relationship between h, h1, and d satisfies: h1 = h - (K1 - d / 2) × 0.01, where K1 is the distance between the outer wall of the second groove segment 402 and the adjacent side wall of the pole body 302 along the X direction, and K1 > d / 2; the relationship between h, h2, and d satisfies: h2 = h - (K2 - d / 2) × 0.01, where K2 is the distance between the outer wall of the third groove segment 403 and the adjacent side wall of the pole body 302 along the X direction, and K2 > d / 2. This embodiment defines the orthographic projection shape of the lower end of the electrode body 302 on the XY plane as circular, and establishes quantitative relationships between h1 and h, K1, d, and h2 and h, K2, d. Combined with the constraints of K1 > d / 2 and K2 > d / 2, a gap is left between the groove of the annular groove 4 and the electrode body 302. This avoids weakening the structural strength of the electrode base plate 301 due to the groove structure being too close to the electrode body 302. At the same time, this quantitative design allows the compression of the sealing ring 5 to be regularly regulated according to the distance between the groove and the electrode body 302. Combined with the strong structural strength of the electrode base plate 301 near the electrode body 302, it avoids the risk of aging and damage of the sealing ring 5 caused by local overpressure or electrolyte leakage caused by underpressure. It also makes the sealing pressure distribution highly consistent with the stress characteristics of the asymmetrical arrangement of the electrode 3 and the structural strength distribution of the electrode base plate 301, thereby improving the sealing performance and service life of the cell cover assembly.

[0054] Furthermore, such as Figure 7 and Figure 9As shown, along the Z direction, the thickness of the sealing ring 5 is H. The groove depth h of the middle groove section 4011, the groove depth h1 of the second groove section 402, and the groove depth h2 of the third groove section 403 are all less than H, and H satisfies the following relationships with h, h1, and h2 respectively: 20%≤[(Hh) / H]×100%≤45%; 20%≤[(H-h1) / H]×100%≤45%; 20%≤[(H-h2) / H]×100%≤45%. It is understood that in this embodiment, by limiting the groove depth h of the intermediate groove, the groove depth h1 of the second groove, and the groove depth h2 of the third groove to be less than the thickness H of the sealing ring 5, and controlling 20%≤[(Hh) / H]×100%≤45%; 20%≤[(H-h1) / H]×100%≤45%; 20%≤[(H-h2) / H]×100%≤45%, it can ensure that the sealing ring 5 forms a moderate and uniform compression deformation after assembly. This avoids the risk of poor sealing surface contact and electrolyte leakage due to excessively low compression ratio, and also prevents stress fatigue and accelerated aging of the sealing ring 5 due to excessively high compression ratio. This extends the service life of the sealing ring 5. On the other hand, the quantitative design of this compression rate range is compatible with the design of the groove opening of the annular groove 4 and the reserved interval of the pole body 302 to ensure the structural strength of the pole base plate 301. This allows the sealing pressure of the sealing ring 5 to match the bearing capacity of the pole base plate 301, avoiding deformation of the pole base plate 301 due to excessive sealing pressure. At the same time, the segmented gradual groove depth structure of the groove enables the orderly distribution of sealing pressure in the core area and the edge area, further improving the sealing reliability and structural stability of the cell cover assembly, and ensuring its performance consistency during cell charging and discharging cycles and long-term use.

[0055] It can be understood that the ratio (Hh) / H can be, but is not limited to, 0.2, 0.23, 0.25, 0.28, 0.3, 0.33, 0.36, 0.37, 0.39, 0.4, 0.42, 0.43, 0.44, 0.45, or any value between two of these. Similarly, the ratio (H-h1) / H can be, but is not limited to, 0.2, 0.23, 0.25, 0.28, 0.3, 0.33, 0.36, 0.37, 0.39, 0.4, 0.42, 0.43, 0.44, 0.45, or any value between two of these. The ratio (H-h2) / H can be, but is not limited to, 0.2, 0.23, 0.25, 0.28, 0.3, 0.33, 0.36, 0.37, 0.39, 0.4, 0.42, 0.43, 0.44, 0.45 or any range between the two.

[0056] In one embodiment, such as Figure 2 and Figure 9As shown, along the Z direction, the thickness of the pole base plate 301 is T, and the range of the thickness T of the pole base plate 301 is 1.2mm≤T≤3mm, and / or, the relationship between the groove depth h of the intermediate groove section 4011 and the thickness T of the pole base plate 301 satisfies 0.4≤h / T≤1.2. It is understood that in this embodiment, the thickness of the electrode base plate 301 is limited to a range of 1.2mm ≤ T ≤ 3mm. This ensures that the electrode base plate 301 has sufficient structural strength to effectively resist external forces and stress impacts during cell assembly and charge / discharge cycles, avoiding failures such as warping and deformation of the base plate. It also avoids redundancy in the overall volume of the assembly due to excessive thickness of the electrode base plate 301, while taking into account the energy density requirements of the cell. At the same time, by establishing a ratio relationship of 0.4 ≤ h / T ≤ 1.2 between the groove depth h and the thickness T of the electrode base plate 301, the groove depth and the thickness of the electrode base plate 301 are matched. When h / T is in the lower limit range, it can prevent the base plate structural strength from being weakened due to excessive groove depth. When h / T is in the upper limit range, it can provide sufficient compression space for the sealing ring 5 to ensure sealing performance. Combined with the segmented structure of the aforementioned annular groove 4 and the quantitative design of the compression ratio of the sealing ring 5, a synergistic optimization of structural strength and sealing performance is achieved, further improving the reliability and service life of the cell cover assembly.

[0057] It is understood that the value of T can be, but is not limited to, 1.2mm, 1.5mm, 1.8mm, 2.0mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3mm, or any value between two of these. The ratio of h / T can be, but is not limited to, 0.4, 0.6, 0.7, 0.9, 1, 1.1, 1.2, or any value between two of these.

[0058] In one embodiment, the annular groove 4 extends in the same direction as the circumference of the pole base plate 301, and the distance between the orthographic projection edge of the annular groove 4 and the orthographic projection edge of the pole base plate 301 is equal everywhere in the XY plane. It can be understood that by setting the annular groove 4 to extend in the same direction as the circumference of the pole base plate 301, and the distance between the orthographic projection edge of the annular groove 4 and the orthographic projection edge of the pole base 3 on the XY plane, this embodiment, on the one hand, makes the annular groove 4 have a regular annular layout adapted to the pole base plate 301. Combined with the gradual change and quantitative design of the groove depth, this allows the compression pressure of the sealing ring 5 to form a uniform and orderly distribution, ensuring the consistency of the full circumferential seal between the pole base plate 301 and the plastic part, effectively eliminating the risk of electrolyte leakage caused by weak points in the local seal; on the other hand, this... The equidistant design avoids the grooves from getting too close to the edge of the pole base plate 301, which would weaken the structural strength of the base plate edge. This ensures that the load-bearing capacity of the pole base plate 301 is balanced in all circumferential positions, preventing deformation or cracking of the base plate due to local stress concentration. At the same time, the regular annular equidistant structure facilitates standardized processing and forming of the mold, reduces dimensional deviations during production, and improves the mass production consistency and yield of the cell cover assembly. This, together with the aforementioned segmented groove structure and sealing ring 5 compression rate control, further optimizes the sealing reliability and structural stability of the assembly.

[0059] For example, on the XY plane, the distance between the orthographic projection edge of the annular groove 4 and the orthographic projection edge of the pole base plate 301 is not less than 0.5 mm.

[0060] According to an embodiment of the present invention, another aspect provides a battery cell, comprising: a housing and the aforementioned battery cell cover assembly.

[0061] Specifically, the housing has an opening; a cover plate 1 is placed over the opening, and the lower plastic 2 and the pole base plate 301 are located inside the housing.

[0062] The battery cell in this embodiment includes the battery cell cover plate 1 assembly as described above, and has all the beneficial technical effects of the battery cell cover plate assembly, which will not be repeated here.

[0063] Specifically, the battery cell in this embodiment may be cylindrical, cuboid, or other shapes, and this application embodiment is not limited in this respect. Furthermore, the battery cell in this embodiment may be a lithium-ion battery cell, a potassium-ion battery cell, a sodium-ion battery cell, a lithium-sulfur battery cell, etc., with lithium-ion battery cells being particularly preferred.

[0064] The technical effects of the present invention will be described below with reference to some embodiments and comparative examples.

[0065] Table 1

[0066]

[0067] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cell cover assembly, characterized in that, include: Cover plate; The lower plastic, along the Z direction, is located on the lower surface of the cover plate; An electrode post includes an electrode post base plate and an electrode post body disposed on the upper surface of the electrode post base plate along the Z direction. Along the X direction, the electrode post body is eccentrically disposed on the electrode post base plate, and along the Y direction, the electrode post body is centrally disposed on the electrode post base plate. The electrode post body passes sequentially through the lower plastic and the cover plate along the Z direction, with at least a portion of the lower plastic sandwiched between the electrode post base plate and the cover plate. The electrode post base plate has an annular groove surrounding the electrode post body. The annular groove has a pair of first groove segments arranged opposite each other along the Y direction and a second and third groove segments arranged opposite each other along the X direction. Along the X direction, the distance between the second groove segment and the adjacent sidewall of the electrode post body is less than the distance between the third groove segment and the adjacent sidewall of the electrode post body. Along the Y direction, the groove depth h of the portion of the first groove segment corresponding to the electrode post body is greater than the groove depth of other areas of the first groove segment. Along the Z direction, the groove depth of the second groove segment is h1, and the groove depth of the third groove segment is h2, where h > h1 > h2. A sealing ring is sandwiched between the lower plastic and the pole base plate. Along the Z direction, the bottom surface of the sealing ring is in contact with the bottom surface of the annular groove, and a portion of the sealing ring protrudes from the annular groove.

2. The cell cover assembly according to claim 1, characterized in that, The first groove segment includes an intermediate groove segment, a first transition groove segment, and a second transition groove segment. One end of the intermediate groove segment is connected to the second groove segment through the first transition groove segment, and the other end is connected to the third groove segment through the second transition groove segment. The intermediate groove segment corresponds to the lower end of the pole body, and the groove depth of the intermediate groove segment is h. Along the direction away from the intermediate groove segment, the groove depths of the first transition groove segment and the second transition groove segment gradually decrease. The maximum groove depth of the first transition groove segment and the second transition groove segment is equal to the groove depth h of the intermediate groove segment. The minimum groove depth of the first transition groove segment is equal to the groove depth h1 of the second groove segment, and the minimum groove depth of the second transition groove segment is equal to the groove depth h2 of the third groove segment.

3. The cell cover assembly according to claim 2, characterized in that, Along the Y direction, the orthographic projection of the lower end of the pole body toward the intermediate groove section falls within the range of the intermediate groove section.

4. The cell cover assembly according to claim 3, characterized in that, Along the X direction, the width of the lower end of the pole body projected onto the XY plane is W, and the length of the middle groove segment projected onto the XY plane is M, satisfying W≤M≤W+2mm.

5. The cell cover assembly according to claim 2, characterized in that, The lower end of the pole body has a circular orthographic projection on the XY plane, with a diameter of d. The relationship between h, h1, and d satisfies: h1 = h - (K1 - d / 2) × 0.01, where K1 is the distance between the outer wall of the second groove segment and the adjacent side wall of the pole body along the X direction, and K1 > d / 2; the relationship between h, h2, and d satisfies: h2 = h - (K2 - d / 2) × 0.01, where K2 is the distance between the outer wall of the third groove segment and the adjacent side wall of the pole body along the X direction, and K2 > d / 2.

6. The cell cover assembly according to claim 5, characterized in that, Along the Z direction, the thickness of the sealing ring is H. The groove depth h of the middle groove section, the groove depth h1 of the second groove section, and the groove depth h2 of the third groove section are all less than H, and H satisfies the following relationships with h, h1, and h2 respectively: 20%≤[(Hh) / H]×100%≤45%; 20%≤[(H-h1) / H]×100%≤45%; 20%≤[(H-h2) / H]×100%≤45%.

7. The cell cover assembly according to claim 2, characterized in that, Along the Z direction, the thickness of the pole base plate is T, and the value range of the pole base plate thickness T is 1.2mm≤T≤3mm, and / or, the relationship between the groove depth h of the intermediate groove section and the thickness T of the pole base plate satisfies 0.4≤h / T≤1.

2.

8. The cell cover assembly according to any one of claims 1 to 7, characterized in that, The annular groove extends in the same direction as the circumference of the pole base plate. On the XY plane, the distance between the orthographic projection edge of the annular groove and the orthographic projection edge of the pole base plate is equal everywhere.

9. The cell cover assembly according to any one of claims 1 to 7, characterized in that, On the XY plane, there is a gap between the opening of the annular groove and the outer wall of the pole body.

10. A battery cell, characterized in that, include: The shell has an opening; The cell cover assembly according to any one of claims 1 to 9, wherein the cover is disposed over the opening, and the lower plastic and the electrode base plate are located within the housing.

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