Battery cell cover plate assembly, battery cell and power device

Abstract

The present application relates to the technical field of batteries. Disclosed are a battery cell cover plate assembly, a battery cell and a power device. The battery cell cover plate assembly comprises a cover plate, a terminal post, a sealing ring and a heat insulation pad. The cover plate is provided with a first mounting hole. The terminal post comprises a terminal post body and a terminal post welding platform, the terminal post body passing through the first mounting hole, and the terminal post welding platform being located below the cover plate. The sealing ring is sleeved on the outer wall of the terminal post body, and comprises a first sealing section, the bottom area of the first sealing section being S1. The heat insulation pad comprises a first heat insulation region provided between the upper surface of the terminal post welding platform and the first sealing section. A contact area between the first heat insulation region and the sealing ring is S2, and the thickness of the heat insulation pad is T, T and S2 / S1 being required to meet preset conditions. When the terminal post and a tab are welded, the present application can achieve a heat insulation effect on the sealing ring, so as to block welding heat and avoid melting or burning the sealing ring, thereby ensuring the sealing performance of the battery cell cover plate assembly and improving the safety performance of the battery cell.

Description

Battery cell cover plate assembly, battery cell and power device

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202411089387.2, filed on August 9, 2024, and entitled "Battery cell cover plate assembly, battery cell and power device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of battery, in particular to a battery cell cover plate assembly, a battery cell and a power device. BACKGROUND

[0004] With the increasing maturity of lithium ion battery technology, lithium ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the use performance and safety of lithium ion batteries are increasingly required.

[0005] The top cover of the lithium battery is a core component of safety and sealing, and its performance stability is crucial to the cover plate assembly.

[0006] The cover plate assembly of the battery cell includes a sealing ring, which plays a sealing role on the battery cell, and the sealing ring is not heat-resistant. The current cover plate and shell connection process is mainly laser welding. When the tab and the pole are welded, the sealing ring will be affected by the welding heat radiation, which often causes the sealing ring to melt or burn. As a core component of the sealing of the cover plate assembly, once damaged, it may cause serious safety hazards to the battery cell. SUMMARY

[0007] Therefore, the present application provides a battery cell cover plate assembly, a battery cell and a power device to solve the problem that the sealing ring is easily melted or burned during welding, thereby affecting the sealing performance of the battery cell cover plate assembly.

[0008] In a first aspect, the present application provides a battery cell cover plate assembly, comprising a cover plate, a pole, a sealing ring and a heat insulation pad. The cover plate is provided with a first mounting hole; the pole comprises a pole body and a pole welding platform protruding from the bottom of the pole body, the pole body penetrates through the first mounting hole, and the pole welding platform is located below the cover plate; the sealing ring is sleeved on the outer wall of the pole body, and the sealing ring comprises a first sealing section extending in the radial direction, the first sealing section is located between the lower surface of the cover plate and the upper surface of the pole welding platform, the bottom area of the first sealing section is S1, and the unit is "mm 2 "; the heat insulation pad comprises a first heat insulation zone located between the upper surface of the pole welding platform and the first sealing section; the contact area of the first heat insulation zone with the sealing ring is S2, and the unit is "mm 2", the thickness of the heat insulation pad is T, and the unit is "mm"; and the following conditions are met: when 0.3 mm≤T≤0.7 mm, 80%≤S2 / S1≤100%; and when 0.7 mm

[0009] Beneficial effects: by arranging the heat insulation pad between the upper surface of the pole welding platform and the first sealing section of the sealing ring, the sealing ring can be insulated when the pole and the lug are welded, and the welding heat is blocked. By controlling the value of T and S2 / S1, it can be ensured that the sealing ring does not melt or burn during the welding of the pole and the lug, thereby ensuring the sealing performance of the battery cover plate assembly and improving the safety performance of the battery.

[0010] In an optional embodiment, the thermal resistance of the heat insulation pad is θ, and the unit is "㎡K / W", θ=L / (λS2), wherein L is the length of the conduction path, and the unit is "mm", L=T; λ is the thermal conductivity of the heat insulation pad, and the unit is "w / (m·k)", and the following conditions are met: 0.024 W / (m·k)<λ<0.2 W / (m·k).

[0011] In an optional embodiment, the lower plastic is further arranged below the cover plate, the lower plastic is provided with a second mounting hole corresponding to the first mounting hole; the pole body sequentially penetrates the second mounting hole and the first mounting hole, the pole welding platform is located on the lower surface of the lower plastic, the sealing ring is arranged in the second mounting hole and the first mounting hole, and the heat insulation pad comprises a second heat insulation area arranged between the lower plastic and the upper surface of the pole welding platform.

[0012] In an optional embodiment, the sealing ring comprises a second sealing section extending in the axial direction from the inner ring of the first sealing section, and the second sealing section is arranged between the pole body and the inner wall of the first mounting hole.

[0013] In an optional embodiment, the heat insulation pad is provided with a third mounting hole matched with the pole body, and the heat insulation pad is sleeved on the outer wall of the pole body through the third mounting hole.

[0014] In an optional embodiment, the pole body is located in the middle part of the pole welding platform.

[0015] In an optional embodiment, the shape of the heat insulation pad matches the upper surface of the pole welding platform.

[0016] In an optional embodiment, the side of the heat insulation pad facing the pole welding platform is provided with an adhesive.

[0017] In a second aspect, the application further provides an electric core, comprising a shell, an electrode assembly and the electric core cover plate assembly of any one of the above technical solutions. The shell has an open end; the electrode assembly is arranged in the shell and is provided with a tab; the electric core cover plate assembly is arranged at the open end of the shell, and the pole post of the electric core cover plate assembly is in conductive connection with the tab.

[0018] Beneficial effects: Because the electric core comprises the electric core cover plate assembly, the same effects as the electric core cover plate assembly are achieved, which will not be repeated here.

[0019] In a third aspect, the application further provides a power device comprising the electric core of the above technical solution.

[0020] Beneficial effects: Because the power device comprises the electric core, the same effects as the electric core are achieved, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the application, the drawings needed in the specific embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0022] Fig. 1 is a schematic diagram of the overall structure of an electric core cover plate assembly according to an embodiment of the application;

[0023] Fig. 2 is an exploded view of the electric core cover plate assembly shown in Fig. 1 from a first perspective;

[0024] Fig. 3 is an exploded view of the electric core cover plate assembly shown in Fig. 1 from a second perspective;

[0025] Fig. 4 is a schematic diagram of the structure after the pole post is assembled with the thermal insulation pad;

[0026] Fig. 5 is a top view of Fig. 4;

[0027] Fig. 6 is a sectional view along A-A in Fig. 5;

[0028] Fig. 7 is a top view of the thermal insulation pad;

[0029] Fig. 8 is an axial sectional view of the sealing ring in Fig. 2;

[0030] Fig. 9 is a sectional view of the electric core cover plate assembly shown in Fig. 1 along the axial direction of the pole post;

[0031] Fig. 10 is a schematic diagram of the structure of the electric core cover plate assembly shown in Fig. 1 welded with the tab;

[0032] Explanation of reference signs: 1, cover plate; 101, first mounting hole; 2, pole column; 201, pole column body; 202, pole column welding platform; 3, sealing ring; 301, first sealing section; 302, second sealing section; 4, heat insulation pad; 401, third mounting hole; 5, lower plastic; 501, second mounting hole; 6, riveting block; 7, upper plastic; 10, battery cell cover plate assembly; 20, electrode assembly; 2001, tab. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0034] For the cover plate 1 assembly in the related art, the sealing ring 3 is prone to burn or melt during the welding of the pole column 2 and the tab 2001, thereby affecting the sealing performance of the battery cell. In order to avoid this situation, the welding process requirement of the cover plate 1 needs to be improved, which becomes a restricting factor for improving the yield of the battery cell.

[0035] The present application can solve the above technical problems.

[0036] The embodiments of the present application will be described below with reference to FIGS. 1 to 10.

[0037] According to the embodiments of the present application, in one aspect, a battery cell cover plate assembly 10 is provided, which comprises a cover plate 1, a pole column 2, a sealing ring 3, and a heat insulation pad 4. The cover plate 1 is provided with a first mounting hole 101; the pole column 2 comprises a pole column body 201 and a pole column welding platform 202 protruding from the bottom of the pole column body 201, the pole column body 201 penetrates through the first mounting hole 101, and the pole column welding platform 202 is located on the lower surface of the cover plate 1; the sealing ring 3 is sleeved on the outer wall of the pole column body 201, and the sealing ring 3 comprises a first sealing section 301 extending in the radial direction, the first sealing section 301 is located between the lower surface of the cover plate 1 and the upper surface of the pole column welding platform 202, the bottom area of the first sealing section 301 is S1, and the unit is “mm 2 ”; the heat insulation pad 4 comprises a first heat insulation area located between the upper surface of the pole column welding platform 202 and the first sealing section 301; the contact area of the first heat insulation area with the sealing ring 3 is S2, the unit is “mm 2 ”, and the thickness of the heat insulation pad 4 is T, the unit is “mm”; and the following conditions are met:

[0038] When 0.3 mm≤T≤0.7 mm and 80%≤S2 / S1≤100%, the sealing ring 3 is not prone to burn or melt during the welding of the pole column 2 and the tab 2001, and the sealing performance of the battery cell is improved.

[0039] When 0.7mm < T≤ 1.5mm, 45%≤ S2 / S1≤ 100%.

[0040] By arranging the heat insulation pad 4 between the upper surface of the pole column welding station 202 and the first sealing section 301 of the sealing ring 3, the sealing ring 3 can be insulated when the pole column 2 and the tab 2001 are welded, and the welding heat is blocked. By controlling the value of T and S2 / S1, it can be ensured that the sealing ring 3 does not melt or burn during the welding process of the pole column 2 and the tab 2001, thereby ensuring the sealing performance of the battery cover plate assembly 10 and improving the safety performance of the battery. Specifically, as shown in FIG. 8, the range indicated by L1 is the first sealing section 301 of the sealing ring 3.

[0041] Specifically, the thickness T of the heat insulation pad 4 cannot be less than 0.3mm, otherwise, the material is too thin, the material process requirement is high, and the material cost is high; at the same time, the structural strength of the heat insulation pad 4 is relatively low, and it is easy to deform, tear, and drop, which may cause poor sealing and internal short circuit.

[0042] The thickness T of the heat insulation pad 4 cannot be greater than 1.5mm, otherwise, the material is too thick, which increases the material cost and weight of the heat insulation pad 4, and the greater the thickness T of the heat insulation pad 4, the greater the total height of the pole column 2, the greater the metal density, and the higher the material cost. At the same time, it occupies the internal space of the battery, which affects the capacity of the battery.

[0043] In order to ensure the structural strength, the specification of the heat insulation pad 4 cannot be too small. S2 / S1 cannot be less than 45%, and the structure height ratio is reasonable, which has stability. Otherwise, S2 / S1 less than 45% will cause poor sealing and battery failure. At the same time, the sealing ring 3 itself has a small size, if both of them have a small proportion, the size of the heat insulation pad 4 is small, the forming and assembly are difficult, the risk of deformation failure is relatively increased, and it is not conducive to automatic production.

[0044] Therefore, according to the thickness T of the heat insulation pad 4, S2 / S1 is controlled in different ranges, the heat insulation pad 4 can not only ensure the heat insulation effect, but also meet the structural strength of the heat insulation pad 4, reduce the process difficulty and assembly difficulty, ensure the sealing effect, control the cost and ensure the capacity of the battery.

[0045] The heat insulation pad 4 is a thin-walled planar structure with small volume and certain structural strength, simple processing technology, easy assembly, and automatic batch production.

[0046] Finally, since the heat insulation pad 4 is used to block the welding heat of the sealing ring 3, rather than replacing the existing sealing ring or pole column with a high-temperature-resistant sealing ring or pole column, the cost can be saved while ensuring the heat insulation effect of the sealing ring 3.

[0047] In some embodiments, the thermal resistance of the heat insulation pad 4 is θ, with a unit of "㎡K / W", θ = L / (λS2), where L is the length of the conduction path, with a unit of "mm", L = T, i.e. the thickness of the heat insulation pad 4, λ is the thermal conductivity of the heat insulation pad 4, with a unit of "w / (m×k)", which can also be expressed as w / (m·k), and satisfies: 0.024W / (m.k) < λ < 0.2W / (m.k).

[0048] where S2 is the heat transfer area, i.e. the contact area between the heat insulation pad 4 and the sealing ring 3, with a unit of "mm 2 ". The thermal resistance θ is the resistance ability of an object to conduct heat flow, which is proportional to the length L of the conduction path, inversely proportional to the contact area S2, and inversely proportional to the thermal conductivity λ of the material.

[0049] By selecting a material with a thermal conductivity λ in the range of 0.024W / (m.k) to 0.2W / (m.k), the heat resistance of the heat insulation pad 4 can reach 200℃, and good heat insulation effect can be achieved.

[0050] Since the lower plastic 5 is usually made of plastic material, the lower plastic 5 plays a supporting and insulating role in the battery cell cover plate assembly 10. When the pole 2 and the tab 2001 are welded, the lower plastic 5 will inevitably be burned and melted by the welding heat, which will affect the supporting and insulating properties of the lower plastic 5 in the battery cell cover plate assembly 10.

[0051] To further solve this technical problem, in some embodiments, a lower plastic 5 is further included, which is arranged below the cover plate 1. The lower plastic 5 is provided with a second mounting hole 501 corresponding to the first mounting hole 101. The pole body 201 penetrates the second mounting hole 501 and the first mounting hole 101 in sequence, and the pole welding platform 202 is located on the lower surface of the lower plastic 5. The sealing ring 3 is arranged in the second mounting hole 501 and the first mounting hole 101, and the heat insulation pad 4 includes a second heat insulation area arranged between the lower plastic 5 and the upper surface of the pole welding platform 202. Specifically, as shown in FIG. 9, the range indicated by L3 is the first heat insulation area, and the range indicated by L4 is the second heat insulation area.

[0052] In this way, the first heat insulation area of the heat insulation pad 4 directly contacts the bottom surface of the sealing ring 3, mainly playing a heat insulation role for the sealing ring 3. The second heat insulation area of the heat insulation pad 4 contacts or corresponds to the bottom of the lower plastic 5, ensuring that the heat insulation pad 4 can simultaneously play a heat insulation role for the lower plastic 5, preventing the sealing ring 3 and the lower plastic 5 in the battery cell cover plate assembly 10 from being burned or melted due to welding heat, ensuring the sealing and insulating properties of the battery cell cover plate assembly 10, and improving the safety performance of the battery cell.

[0053] Optionally, the lower plastic 5 is an electrolyte-resistant material. By setting the heat insulation pad 4 to achieve the heat insulation effect of the lower plastic 5, instead of directly replacing the lower plastic 5 which is insulation, electrolyte-resistant and high-temperature-resistant, the cost can be reduced.

[0054] In some embodiments, the sealing ring 3 includes a second sealing section 302 extending axially from the inner ring of the first sealing section 301, and the second sealing section 302 is arranged between the pole post body 201 and the inner wall of the first mounting hole 101.

[0055] The second sealing section 302 of the sealing ring 3 is located between the pole post body 201 and the inner wall of the first mounting hole 101, which can seal the pole post body 201 and the cover plate 1 in the axial direction, and improve the overall sealing effect of the battery cell cover plate assembly 10. Specifically, as shown in FIG. 8, the range indicated by L1 is the first sealing section 301 of the sealing ring 3, and the range indicated by L2 is the second sealing section 302 of the sealing ring 3. The shape of the second sealing section 302 is not limited, one of which is a two-section structure with a step as shown in FIG. 8, which can improve the sealing effect between the pole post body 201 and the inner wall of the first mounting hole 101; and the other is a cylindrical structure without a step, that is, the overall sealing ring 3 constitutes a two-section structure.

[0056] In some embodiments, the heat insulation pad 4 is provided with a third mounting hole 401 adapted to the pole post body 201, and the heat insulation pad 4 is sleeved on the outer wall of the pole post body 201 through the third mounting hole 401.

[0057] The heat insulation pad 4 is provided with the third mounting hole 401 which can be adapted to the pole post body 201, so that the heat insulation pad 4 can be sleeved on the pole post body 201 to play a limiting role, and the heat insulation pad 4 will not move or fall off after assembly.

[0058] In some embodiments, the pole post body 201 is located in the middle of the pole post welding platform 202.

[0059] Therefore, the third mounting hole 401 adapted thereto is also located in the middle of the heat insulation pad 4. Since the pole post body 201 and the sealing ring 3 are in direct contact, the pole post body 201 is arranged in the middle of the pole post welding platform 202, and the heat insulation pad 4 is arranged on the pole post welding platform 202 and located directly below the sealing ring 3, which can improve the heat insulation effect of the sealing ring 3.

[0060] In some embodiments, the shape of the heat insulation pad 4 matches the upper surface of the pole post welding platform 202.

[0061] The shape of the heat insulation pad 4 matches the upper surface of the pole post welding platform 202, so that the contact area between the heat insulation pad 4 and the bottom surface of the sealing ring 3 accounts for 100% of the bottom area of the sealing ring 3, improving the heat insulation effect of the heat insulation pad 4.

[0062] In some embodiments, the side of the heat insulation pad 4 facing the pole welding platform 202 is provided with an adhesive. In this way, the heat insulation pad 4 can be prevented from being displaced during assembly.

[0063] In some embodiments, the upper part of the pole body 201 is fixedly connected by the riveting block 6, the upper plastic 7 and the cover plate 1.

[0064] The upper part of the pole body 201 protrudes from the cover plate 1 after penetrating the first mounting hole 101, and the pole body 201 and the cover plate 1 are fixedly connected in an insulating manner by the riveting block 6 and the upper plastic 7.

[0065] The following provides specific implementation cases.

[0066] Experimental conditions:

[0067] During laser welding of the tab 2001, the welding input power P is 1200W, and the welding speed is 500mm / s.

[0068] The materials of the heat insulation pads 4 are the same, both being silica gel, and the thermal conductivity λ is 0.12W / (m.k), but the thickness T of the heat insulation pad 4 and the ratio of the contact area S2 of the heat insulation pad 4 to the bottom area S1 of the heat insulation pad 4 are different in different implementation cases.

[0069] The burning and leakage of each implementation case are detected. The experimental results are shown in Table 1.

[0070] Table 1:

[0071] According to Table 1, it can be seen that:

[0072] For the third experimental case, the heat insulation effect can be achieved, there is no burning and no leakage, but T=0.1mm, which is less than the lower limit value 0.3mm of T, resulting in that the material of the heat insulation pad 4 is too thin, and there are abnormal phenomena such as deformation, tearing and material falling during assembly, which does not meet the requirements.

[0073] For the fourth implementation case, since S2 / S1 is less than 80%, the heat insulation effect cannot be achieved, and there are burning and slight leakage, which does not meet the requirements.

[0074] For the thirteenth implementation case, since S2 / S1 is less than 45%, the heat insulation effect cannot be achieved, and there are burning and slight leakage, which does not meet the requirements.

[0075] For the seventeenth implementation case, because the thickness T is increased, the test results are no burning and no leakage, but since S2 / S1 is less than 45%, the size of the heat insulation pad 4 is small, and there are difficulties in forming and assembling, which does not meet the requirements.

[0076] For the twenty-first embodiment, because the thickness T increases, the test results are no burn, no leakage, but because S2 / S1 is less than 45%, the size of the thermal insulation pad 4 is small, and there are difficulties in forming and assembling, which does not meet the requirements.

[0077] For the twenty-third embodiment, because the thickness T increases, the test results are no burn, no leakage, but because S2 / S1 is less than 45%, the size of the thermal insulation pad 4 is small, and there are difficulties in forming and assembling, which does not meet the requirements.

[0078] For the twenty-sixth embodiment, because the thickness T increases, the test results are no burn, no leakage, but because S2 / S1 is less than 45%, the size of the thermal insulation pad 4 is small, and there are difficulties in forming and assembling, which does not meet the requirements.

[0079] For the twenty-ninth and thirtieth embodiments, because the thickness T increases, the test results are no burn, no leakage, but at the same time, because the thickness T is greater than the upper limit value 1.5 mm, the total height of the pole 2 is large, which occupies the internal space of the battery cell and affects the capacity of the battery cell, which does not meet the requirements.

[0080] The remaining embodiments can achieve good thermal insulation effect on the sealing ring 3 when meeting the limited range of T and S2 / S1, ensure that the sealing ring 3 is not burned and leaked due to the heat during the welding of the tab 2001, and ensure the safety of the battery cell while meeting other requirements of the battery cell design.

[0081] According to the embodiments of the present application, the second aspect further provides a battery cell including a shell, an electrode assembly 20, and the battery cell cover plate assembly 10 of any one of the above embodiments. The shell has an open end; the electrode assembly 20 is arranged in the shell, and the electrode assembly 20 is provided with a tab 2001; the battery cell cover plate assembly 10 is arranged at the open end of the shell, and the pole 2 of the battery cell cover plate assembly 10 is in conductive connection with the tab 2001.

[0082] Since the battery cell of the present embodiment includes the battery cell cover plate assembly 10 of the above embodiment, by arranging the thermal insulation pad 4 between the upper surface of the pole welding table 202 and the first sealing section 301 of the sealing ring 3, the sealing ring 3 can be insulated and blocked from the welding heat when the pole 2 and the tab 2001 are welded. By informing the ratio of S2 and S1 and the range of T, it can be ensured that the sealing ring 3 is not melted or burned during the welding of the pole 2 and the tab 2001, thereby ensuring the sealing performance of the battery cell cover plate assembly 10 and improving the safety performance of the battery cell.

[0083] According to the embodiments of the present application, the third aspect further provides a power device including the battery cell of the above technical solution.

[0084] Because the power device includes the battery cell in the above-described embodiments, has the same effect with the battery cell cover plate assembly 10, here will not repeat.

[0085] Although the embodiments of the present application are described in conjunction with the accompanying drawings, various modifications and changes can be suggested by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes are intended to fall within the scope of the appended claims.

Claims

1. An electrochemical cell cover plate assembly, comprising: The application relates to a cover plate for a battery cell, which comprises: a cover plate provided with a first mounting hole; a pole column comprising a pole column body and a pole column welding table protruding from the bottom of the pole column body, wherein the pole column body penetrates through the first mounting hole, and the pole column welding table is located below the cover plate; A sealing ring is sleeved on the outer wall of the pole body, the sealing ring comprises a radially extending first sealing section, the first sealing section is arranged between the lower surface of the cover plate and the upper surface of the pole welding table, the bottom area of the first sealing section is S1, unit is "mm 2 "; The heat insulation pad comprises a first heat insulation area arranged between the upper surface of the pole welding table and the first sealing section; the contact area of the first heat insulation area with the sealing ring is S2, in units of "mm 2 ", and the thickness of the heat insulation pad is T, in units of "mm"; satisfying: when 0.3mm<=T<=0.7mm, 80%<=S2 / S1<=100%; when 0.7mm 2. The cell cover plate assembly of claim 1, wherein, The thermal conductivity of the heat insulation pad is lambda, and the unit is "w / (m.k)", satisfying 0.024W / (m.k)<lambda<0.2W / (m.k).

3. The cell cover plate assembly of claim 2, wherein, The thermal resistance of the heat insulation pad is theta, and the unit is "m2K / W", theta=L / (lambdaS2), wherein L is the length of the conduction path, and the unit is "mm", L=T.

4. The cell cover plate assembly of claim 1 or 3, wherein, The application further comprises a lower plastic, which is arranged below the cover plate and is provided with a second mounting hole corresponding to the first mounting hole; the pole column body penetrates through the second mounting hole and the first mounting hole in sequence, the pole column welding table is located on the lower surface of the lower plastic, the sealing ring is arranged in the second mounting hole and the first mounting hole, and the heat insulation pad comprises a second heat insulation area arranged between the lower plastic and the upper surface of the pole column welding table.

5. The cell cover plate assembly of claim 1 or 3, wherein, The sealing ring comprises a second sealing section extending in the axial direction from the inner ring of the first sealing section, and the second sealing section is arranged between the pole column body and the inner wall of the first mounting hole.

6. The cell cover plate assembly of claim 1 or 3, wherein, The heat insulation pad is provided with a third mounting hole matched with the pole column body, and the heat insulation pad is sleeved on the outer wall of the pole column body through the third mounting hole.

7. The cell cover plate assembly of claim 1 or 3, wherein, The pole column body is located in the middle part of the pole column welding table.

8. The cell cover plate assembly of claim 1 or 3, wherein, The shape of the heat insulation pad matches the upper surface of the pole column welding table.

9. The cell cover plate assembly of claim 1 or 3, wherein, The side of the heat insulation pad facing the pole column welding table is provided with a back glue.

10. An electric cell characterized by The application relates to a battery cell, which comprises: a shell with an open end; an electrode assembly arranged in the shell, wherein the electrode assembly is provided with a tab; the electrode cell cover plate assembly in any one of claims 1 to 8 is arranged at the open end of the shell, and the pole column of the electrode cell cover plate assembly is in conductive connection with the tab.

11. A power plant characterized by The application relates to a battery cell, which comprises: the electrode cell in claim 10.

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