A single cell and a battery pack

Abstract

The application discloses a single battery and a battery pack, and belongs to the technical field of batteries. The single battery comprises a cover plate assembly and an electrode assembly, and the electrode assembly is arranged on one side of the cover plate assembly in the thickness direction. The cover plate assembly comprises a cover plate body, a pole, a first insulating piece and a first sealing piece. The cover plate body is provided with an assembly hole. The pole comprises a column body part and a plate body part which are arranged in the thickness direction and connected. The column body part penetrates the assembly hole, and the plate body part is located on the side of the cover plate body facing the electrode assembly. A groove is formed on the side of the plate body part facing the cover plate body, and the groove surrounds the column body part. The first insulating piece is clamped between the plate body part and the cover plate body. The first sealing piece is embedded in the groove and clamped between the first insulating piece and the plate body part. The first sealing piece blocks the electrolyte from entering the assembly gap between the column body part and the first insulating piece through the gap between the plate body part and the first insulating piece, thereby reducing the short circuit risk of the single battery and improving the safety of the single battery.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a single battery and a battery pack. BACKGROUND

[0002] In the process of assembling the cover plate assembly in the single battery, the insulation and sealing assembly of the pole and the cover plate body are achieved by compressing the sealing ring. However, in the process of liquid injection, the assembly gap between the sealing ring and the lower plastic has a safety hazard, which affects the quality and service life of the battery. SUMMARY

[0003] The application provides a single battery, which aims to overcome the technical problem that the assembly gap between the sealing ring and the first insulating piece has a safety hazard; another object of the application is to provide a battery pack.

[0004] Technical scheme: The application discloses a single battery, which comprises a cover plate assembly and an electrode assembly, wherein the electrode assembly is arranged on one side of the cover plate assembly in the thickness direction.

[0005] The cover plate assembly comprises:

[0006] a cover plate body, which is provided with an assembly hole;

[0007] a pole, which comprises a column body part and a plate body part arranged and connected in the thickness direction, the column body part penetrates the assembly hole, and the plate body part is located on the side of the cover plate body facing the electrode assembly, the side of the plate body part facing the cover plate body is provided with a groove, and the groove surrounds the column body part;

[0008] a first insulating piece, which is clamped between the plate body part and the cover plate body;

[0009] a first sealing piece, which is embedded in the groove and clamped between the first insulating piece and the plate body part.

[0010] In some embodiments, along the thickness direction, the groove has a thickness dimension h, and the first sealing piece has a thickness dimension H, and 0.15≤(H-h) / H≤0.45 is satisfied;

[0011] The cross section of the groove has a width dimension w, and 1≤w / h≤3 is satisfied;

[0012] The groove has a cross-sectional area S1, and the cross-sectional area of the first sealing piece in the uncompressed state is S2, and 0.8≤S1 / S2≤1.2 is satisfied.

[0013] In some embodiments, the groove has a minimum dimension c from the outer edge of the plate body part, and c≥0.5mm is satisfied.

[0014] In some embodiments, the first sealing member is made of rubber.

[0015] In some embodiments, the cover plate assembly further comprises a riveting block arranged on the side of the cover plate body away from the electrode assembly and connected with the columnar portion, and the riveting block and the plate body portion jointly hold the cover plate body.

[0016] In some embodiments, the cover plate assembly further comprises a second insulating member arranged on the side of the cover plate body away from the electrode assembly and sandwiched between the cover plate body and the riveting block.

[0017] In some embodiments, the cover plate assembly further comprises a second sealing member, which comprises a first sealing segment and a second sealing segment connected with each other, the first sealing segment is arranged in the assembly hole and sandwiched between the second insulating member and the plate body portion, and the second sealing segment is sandwiched between the cover plate body and the plate body portion.

[0018] In some embodiments, a gap is formed between the second sealing segment and the first insulating member, and the gap has a minimum size d of 2 mm or more from the groove.

[0019] In some embodiments, the first sealing member has a cross section in any one of a circle, a ring, an ellipse, and a rectangle.

[0020] The embodiments of the present application also provide a battery pack comprising the single battery as described in the above embodiments.

[0021] Beneficial effects: The single battery of the embodiments of the present application comprises a cover plate assembly and an electrode assembly, the electrode assembly is arranged on one side of the cover plate assembly in the thickness direction; the cover plate assembly comprises a cover plate body, a pole column, a first insulating member, and a first sealing member, the cover plate body is provided with an assembly hole; the pole column comprises a columnar portion and a plate body portion arranged in the thickness direction and connected with each other, the columnar portion is arranged in the assembly hole, the plate body portion is arranged on the side of the cover plate body facing the electrode assembly, the side of the plate body portion facing the cover plate body is provided with a groove, and the groove surrounds the columnar portion; the first insulating member is sandwiched between the plate body portion and the cover plate body; and the first sealing member is embedded in the groove and sandwiched between the first insulating member and the plate body portion. By arranging the groove on the side of the plate body portion of the pole column facing the cover plate body and arranging the first sealing member in the groove, the electrolyte is prevented from entering the assembly gap between the columnar portion and the first insulating member through the gap between the plate body portion and the first insulating member, so that the electrolyte is prevented from conducting the pole column and the cover plate body to cause short circuit of the single battery, and the safety of the single battery is improved.

[0022] The battery pack of the embodiments of the present application comprises the single battery as described in the above embodiments, and therefore can have all the technical features and technical effects of the single battery, which will not be described herein again. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a three-dimensional structural diagram of a cover plate assembly in a single battery cell according to an embodiment of this application;

[0025] Figure 2 This is a top view of a cover plate assembly in a single battery cell according to an embodiment of this application;

[0026] Figure 3 for Figure 2 Cross-sectional view along the AA direction;

[0027] Figure 4 for Figure 2 Cross-sectional view along the middle BB direction;

[0028] Figure 5 This is a three-dimensional structural diagram of the pole post in the cover plate assembly of this application embodiment;

[0029] Figure 6 This is a top view of the pole post in the cover plate assembly according to an embodiment of this application;

[0030] Figure 7 This is a schematic diagram of the structure of the first sealing element in the cover plate assembly according to an embodiment of this application;

[0031] Reference numerals: 1. Cover plate assembly; 11. Cover plate body; 110. Assembly hole; 12. Pole post; 121. Post body; 122. Plate body; 1220. Groove; 13. First insulating element; 14. First sealing element; X, thickness direction; 1221. Outer edge; 15. Second sealing element; 151. First sealing section; 152. Second sealing section; 10. Gap; 16. Riveting block; 17. Second insulating element. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0033] In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or component referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, the meaning of "a plurality of" is two or more, at least one of which can be one, two or more, unless otherwise explicitly specified. The terms "first", "second", "third" and the like are only for the convenience of description and are named by numbering the parts or embodiments, and do not imply an important order between the parts or between the embodiments.

[0034] It should also be noted that in the drawings of the present application, the arrow marked X indicates the thickness direction, and in the description of the present application, the thickness direction is introduced to more clearly define the structure and relative positional relationship of each component in a single battery and a battery pack.

[0035] As a prologue of the embodiments of the present application, the cover plate assembly in the single battery is assembled by compressing the sealing ring to realize the insulation and sealing assembly of the pole and the cover plate body. However, during the liquid injection process, the assembly gap between the sealing ring and the lower plastic has a safety hazard, which affects the quality and service life of the battery. For example, after the battery is assembled, liquid injection is required, and during the liquid injection process, part of the electrolyte will inevitably enter the assembly gap between the lower plastic and the sealing ring along the gap between the cover plate body and the lower plastic, thereby causing the electrolyte to conduct the pole and the cover plate body, reducing the resistance of the entire negative electrode of the battery, and further affecting the edge voltage at the negative electrode of the battery, resulting in corrosion and leakage of the battery, and ultimately causing short circuit of the single battery. During the use of the battery, short circuit may cause serious safety problems such as overheating, fire and even explosion.

[0036] Therefore, the embodiments of the present application provide a single battery, which aims to solve at least one of the above technical problems.

[0037] Please refer to Figures 1 to 7As shown, the single battery disclosed by the embodiment of the application comprises a cover plate assembly 1 and an electrode assembly, the electrode assembly is arranged on one side of the thickness direction X of the cover plate assembly 1; the cover plate assembly 1 comprises a cover plate body 11, a pole 12, a first insulating part 13 and a first sealing part 14; it should be understood that the cover plate assembly 1 plays a key role in protecting the internal structure of the battery and realizing external connection in the single battery, on the one hand, the cover plate body 11 in the cover plate assembly 1 can seal the electrode assembly and the electrolyte in the battery in a relatively stable environment, prevent foreign matters from entering the battery, and avoid interference with the chemical reaction in the battery; on the other hand, the pole 12 on the cover plate assembly 1 is the interface for connecting the battery and the external circuit, so that the battery can be charged and discharged. The electrode assembly is the core part of the battery to generate electric energy through chemical reaction.

[0038] Specifically, the cover plate body 11 is provided with an assembly hole 110; the pole 12 comprises a column part 121 and a plate part 122 arranged and connected along the thickness direction X, the column part 121 penetrates the assembly hole 110, and the plate part 122 is located on the side of the cover plate body 11 facing the electrode assembly, the side of the plate part 122 facing the cover plate body 11 is provided with a groove 1220, and the groove 1220 surrounds the column part 121; the first insulating part 13 is clamped between the plate part 122 and the cover plate body 11, and is mainly used for realizing the insulation between the pole 12 and the cover plate body 11; the first sealing part 14 is embedded in the groove 1220 and clamped between the first insulating part 13 and the plate part 122. It should be understood that by opening the groove 1220 on the plate part 122 of the pole 12 and embedding the first sealing part 14, the electrolyte is effectively blocked from entering the assembly gap 10 between the column part 121 and the first insulating part 13 from the gap between the plate part 122 and the first insulating part 13, thereby greatly reducing the risk of short circuit of the single battery and improving the safety of the single battery. Furthermore, the first sealing part 14 can increase the sealing performance between the pole 12 and the cover plate body 11, which helps to maintain the stability of the internal environment of the battery, prevent the electrolyte leakage from corroding and damaging other components in the battery, and thus prolong the service life of the battery. By opening the groove 1220, on the one hand, the installation and positioning of the first sealing part 14 are provided, the assembly difficulty is reduced, the assembly efficiency and stability are improved; at the same time, the thickness space of the cover plate assembly 1 is reduced, and by accurately controlling the installation position and compression amount of the first sealing part 14, the sealing performance of each single battery can be kept highly consistent.

[0039] Please refer to Figure 3As shown, in some embodiments, along the thickness direction X, the groove 1220 has a thickness dimension h, the first seal 14 in uncompressed state has a thickness dimension H, satisfying 0.15≤(H-h) / H≤0.45; the cross section of the groove 1220 has a width dimension w, satisfying 1≤w / h≤3; the groove 1220 has a cross-sectional area S1, and the first seal 14 in uncompressed state has a cross-sectional area S2, satisfying 0.8≤S1 / S2≤1.2. It is to be understood that by limiting the thickness dimension of the portion of the first seal 14 exposed outside the groove 1220 to between 15% and 45% of the thickness dimension of the first seal 14 in uncompressed state, the compression amount of the first seal 14 is limited, the sealing effect between the first insulating member 13 and the plate body portion 122 is enhanced, the leakage of electrolyte inside the battery is effectively prevented, and the stability of the chemical environment inside the battery is maintained.

[0040] Specifically, (H-h) / H can be any value in 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45 or a range value between any two values. If the compression amount is too small, the first seal 14 can not be able to tightly fill the gap 10 between the groove 1220 and the surrounding components, resulting in poor sealing effect and easy leakage of electrolyte from the gap. If the compression amount is too large, on the one hand, it will cause excessive deformation of the first seal 14, which can damage the structure of the first seal 14 and reduce its service life. On the other hand, the excessive pressure can cause the first seal 14 to extrude out of the groove 1220, which will also affect the sealing effect.

[0041] At the same time, by limiting the ratio between the width dimension and the thickness dimension of the groove 1220 to be between 1 and 3, and the ratio between the cross-sectional area of the groove 1220 and the cross-sectional area of the first seal 14 to be between 0.8 and 1.2, it is ensured that the first seal 14 can be in an optimal filling state in the groove 1220. When the width and thickness are in a proper ratio, the first seal 14 can uniformly distribute pressure in the groove 1220 and better fit the wall surface of the groove 1220. The reasonable ratio of the cross-sectional areas ensures that the first seal 14 can completely fill the groove 1220 without local vacancies or excessive filling, thereby further enhancing the sealing effect, effectively preventing the leakage of electrolyte inside the battery, and maintaining the stability of the chemical environment inside the battery.

[0042] Specifically, w / h can be any value in 1, 1.5, 2, 2.5, 3 or a range value between any two values. Specifically, S1 / S2 can be any value in 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20 or a range value between any two values.

[0043] If S1 / S2 is less than 0.8, the groove 1220 is too small relative to the first seal 14, and the first seal 14 can not be completely fitted into the groove 1220, with some of the first seal 14 material being extruded outside the groove 1220, resulting in uneven distribution of the first seal 14 around the groove 1220, and gaps being easily generated in places where the first seal 14 and the edge of the groove 1220 do not contact closely during assembly and use of the battery. If S1 / S2 is greater than 1.2, the cross-sectional area of the groove 1220 is much larger than that of the first seal 14, and the first seal 14 cannot completely fill the space in the groove 1220, with many gaps being present. During operation of the battery, electrolyte can enter these gaps, and since the first seal 14 cannot closely adhere to the wall of the groove 1220, it cannot effectively prevent the electrolyte from flowing in the gaps, so that the electrolyte can pass through these unsealed channels to reach the gap 10 between the main body and the first insulating member 13, thereby causing safety problems such as short circuit of the battery.

[0044] Furthermore, by precisely controlling the above parameters, the first seal 14 can be better fixed in the groove 1220 and is not easily displaced. At the same time, due to the reasonable design of the compression amount and the size, the first seal 14 can have certain elastic buffering when subjected to external force, reducing the possibility of damage to the first seal 14 due to excessive external force, thereby ensuring the stability of the entire battery structure.

[0045] Next, a plurality of embodiments are provided to illustrate the effects of the secondary battery of the present application, wherein some common measurement methods can be selected to measure H, h, w, S1 and S2, for example, vernier calipers, micrometers and other measuring tools can be used to measure the corresponding sizes of the groove 1220 and the first seal 14, and geometric formulas are used to calculate the areas S1 and S2. Image processing methods can also be used to measure H, h, w, S1 and S2. Alternatively, projection methods can also be used to measure H, h, w, S1 and S2, using projection measurement equipment such as digital microscopes or image measurement instruments.

[0046] Among them, the cover plate assembly 1 of the single battery can be disassembled, and any one of chemical analysis method, physical detection method and spectral analysis method can be used to detect whether the electrolyte passes through the first seal 14 and enters the assembly gap 10 between the pole 12 and the first insulating member 13, so as to judge whether the sealing performance between the lower plastic and the cover plate body 11 meets the sealing performance.

[0047] The test results of the embodiments are as follows:

[0048]

[0049] As shown in the above table, in Embodiments 1 to 12, when (H-h) / H*100% is between 15 and 45, w / h is between 1 and 3, and S1 / S2 is between 0.8 and 1.2, the sealing effect between the first insulating member 13 and the plate body portion 122 is good, no electrolyte leaks in the assembly gap 10 between the pole 12 and the first insulating member 13, and the sealing barrier to electrolyte is met. In Embodiments 13 to 18, when S1 / S2 is less than 0.8, the compression ratio of the first sealing member 14 is qualified, the groove 1220 space is large, resulting in poor sealing; when S1 / S2 is greater than 1.2, the compression ratio of the first sealing member 14 is qualified, the groove 1220 space is small, the first sealing member 14 is partially extruded, and the sealing performance is poor. In Embodiments 19 to 21, when the compression ratio of the first sealing member 14 is greater than 45, the compression amount of the first sealing member 14 is too large, the contact area between the first sealing member 14 and the first insulating member 13 is extruded and deformed, and the sealing performance is poor. In Embodiments 22 to 24, when the compression ratio of the first sealing member 14 is less than 15, the compression amount is too small, the first sealing member 14 can not tightly fill the gap 10 between the groove 1220 and the surrounding components, resulting in poor sealing effect, and electrolyte is easily leaked from the gap.

[0050] Referring to Figure 6 In some embodiments, as shown in the above table, the groove 1220 is at least 0.5 mm away from the outer edge 1221 of the plate body portion 122, satisfying c≥0.5 mm. It should be understood that by limiting the minimum distance between the groove 1220 and the outer edge 1221 of the plate body portion 122, the influence of the edge effect can be avoided, and deformation, micro-cracks and other problems are more likely to occur due to material processing, assembly stress and other factors. If the groove 1220 is too close to the outer edge 1221, the micro-deformation or cracks generated in these edge areas can extend to the groove 1220 area, thereby damaging the sealing effect of the first sealing member 14. By setting the groove 1220 at least 0.5 mm away from the outer edge 1221, the groove 1220 area where the sealing member is located is in a relatively stable structure area, and the risk of sealing member failure due to edge deformation or cracks is reduced.

[0051] In some embodiments, the first sealing member 14 is made of rubber material. It should be understood that the first sealing member 14 can be fluororubber with a Shore hardness of 65° to 75°, which has strong acid and strong alkali corrosion resistance, especially electrolyte. After soaking in electrolyte, the first sealing member 14 has a size expansion of less than 20% and a weight of less than 30%; the rubber sealing member can resist the corrosion of electrolyte, maintain its physical and chemical properties unchanged for a long time, and ensure its long-term stability in the battery; the first sealing member 14 is baked at a high temperature of 300℃ for 2 minutes without deformation, and the insulation resistance of the first sealing member 14 is greater than 200MΩ.

[0052] Referring to Figure 1 、 Figure 3 and Figure 4 In some embodiments, the cover plate assembly 1 further comprises a riveting block 16 arranged on the side of the cover plate body 11 away from the electrode assembly and connected with the columnar portion 121, and the riveting block 16 and the plate body portion 122 jointly clamp the cover plate body 11. It should be understood that by arranging the riveting block 16 to be closely connected with the columnar portion 121, the conduction of current between the pole column 12 and the external circuit can be ensured to be smooth. The riveting block 16 and the plate body portion 122 jointly clamp the cover plate body 11 to form a reliable mechanical connection structure. By adopting the double-clamping mode, the connection between the pole column 12 and the cover plate body 11 is more stable, greatly reducing the risk of the pole column 12 loosening or even falling off due to external force; at the same time, during the charging and discharging process of the battery, the pole column 12 will conduct current and at the same time will bear certain thermal stress and mechanical stress. The riveting block 16 and the plate body portion 122 jointly clamp the cover plate body 11, so that the stress borne by the pole column 12 can be more evenly distributed to the cover plate body 11, preventing stress concentration at the connection point of the pole column 12 and the cover plate body 11, avoiding cracks or damage of the cover plate body 11 due to stress concentration, thereby prolonging the service life of the battery and improving the reliability of the battery structure. In addition, since the riveting block 16 and the plate body portion 122 jointly clamp the cover plate body 11, the structure of the cover plate body 11 around the pole column 12 is more compact, which helps to further enhance the insulation performance between the pole column 12 and the cover plate body 11.

[0053] Referring to Figure 3 and Figure 4 In some embodiments, the cover plate assembly 1 further comprises a second insulating member 17 located on the side of the cover plate body 11 away from the electrode assembly and clamped between the cover plate body 11 and the riveting block 16. It should be understood that the second insulating member 17 is arranged on the outside of the cover plate body 11, which can provide an additional electrical insulation barrier for the battery and effectively prevent current from being conducted to the cover plate body 11 through the riveting block 16, further reducing the risk of electric leakage and ensuring the safety and stability of the battery. At the same time, the second insulating member 17 can also play a buffering and isolating role to prevent damage between the cover plate body 11 and the riveting block 16 due to electrochemical corrosion.

[0054] Referring to Figure 3 and Figure 4As shown, in some embodiments, the cover plate assembly 1 further comprises a second sealing member 15, which comprises a first sealing segment 151 and a second sealing segment 152 connected in series. The first sealing segment 151 is arranged in the assembly hole 110 and clamped between the second insulating member 17 and the plate body portion 122, and the second sealing segment 152 is clamped between the cover plate body 11 and the plate body portion 122. It should be understood that the first sealing segment 151 effectively fills the gap that may exist when the column portion 121 passes through the assembly hole 110, preventing the electrolyte from penetrating upward from the assembly hole 110, avoiding the electrolyte from contacting the area between the riveting block 16 and the second insulating member 17, preventing electrical failure caused by electrolyte leakage, and further enhancing the insulation performance between the pole column 12 and the cover plate body 11. The second sealing segment 152 is clamped between the cover plate body 11 and the plate body portion 122, further enhancing the sealing effect of the connection between the cover plate body 11 and the plate body portion 122. The double sealing segments work together to greatly reduce the possibility of electrolyte leakage, and ensure the stability of the internal environment of the battery. The two-segment design of the second sealing member 15 can better adapt to these complex working conditions. By using sealing segments at different positions to respond to pressure and displacement in different directions, the sealing performance is always good, ensuring that the battery can effectively prevent electrolyte leakage in various situations. Furthermore, through the effective sealing of the second sealing member 15, the opportunity for electrolyte to contact other components is reduced, prolonging the service life of components such as the second insulating member 17, the riveting block 16, and the cover plate body 11, thereby improving the reliability and durability of the entire battery. In addition, the two-segment structure design of the second sealing member 15 facilitates assembly to some extent.

[0055] Please refer to Figure 4 As shown, in some embodiments, a gap 10 is formed between the second sealing segment 152 and the first insulating member 13, and the distance between the gap 10 and the groove 1220 is the minimum size d, which satisfies d≥2mm. It should be understood that by limiting the minimum distance between the gap 10 formed by the second sealing segment 152 and the first insulating member 13 and the groove 1220 to be greater than or equal to 2mm, the first sealing member 14 can independently exert a sealing effect in its working area without being affected by the second sealing segment 152, preventing the second sealing segment 152 from interfering with the sealing effect of the first sealing member 14 during the use of the battery (such as in situations where it is subjected to vibration, temperature changes, etc.), maintaining the relative independence of the two sealing structures of the second sealing segment 152 and the first sealing member 14, thereby maintaining the stability of the internal structure of the battery and prolonging the service life of the battery. If the gap 10 is too close to the groove 1220, the second sealing segment 152 may press the area where the first sealing member 14 is located due to a change in position, and even cause damage or deformation of the structural components, thereby damaging the close-fitting state between the first sealing member 14 and the groove 1220.

[0056] Please see Figure 7 As shown, in some embodiments, the cross-section of the first seal 14 is any one of circular, annular, elliptical, or rectangular. It should be understood that a circular cross-section first seal 14 exhibits good uniformity in force distribution and pressure transmission. This uniform force distribution characteristic allows the first seal 14 to maintain good stability within the groove 1220, and during long-term use, the wear degree of each part is relatively consistent, which is beneficial for maintaining the durability of the performance of the first seal 14. An annular cross-section first seal 14 can more effectively utilize the space within the groove 1220. It can achieve sealing of critical areas without occupying excessive space and can better cooperate with other components (such as the terminal post 12, insulating components, etc.), optimizing the internal structural layout of the battery. An elliptical cross-section first seal 14 can be designed according to the specific assembly space shape inside the battery. By adjusting the compression amount in the major and minor axis directions of the elliptical first seal 14, differentiated sealing effects can be achieved. A rectangular cross-section first seal 14 can better fit when in contact with planar structures, effectively filling the gaps between planes.

[0057] This application also provides a battery pack, including the single battery cells as described in the above embodiments. In the above embodiments, the descriptions of each embodiment have different focuses; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0058] The present application provides a detailed description of a single battery cell and a battery pack, and uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of the present application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single-cell battery, characterized in that, include: A cover plate assembly and an electrode assembly, wherein the electrode assembly is disposed on one side of the cover plate assembly in the thickness direction; The cover plate assembly includes: The cover plate body has assembly holes; An electrode post includes a column portion and a plate portion arranged and connected along the thickness direction. The column portion passes through the mounting hole. The plate portion is located on the side of the cover plate body facing the electrode assembly. The plate portion has a groove on the side facing the cover plate body, and the groove surrounds the column portion. The first insulating element is sandwiched between the plate body and the cover plate body; The first sealing element is embedded in the groove and sandwiched between the first insulating element and the plate body portion; The cover plate assembly further includes a riveting block, which is disposed on the side of the cover plate body away from the electrode assembly and connected to the column portion. The riveting block and the plate portion together clamp the cover plate body. The cover plate assembly further includes a second insulating member located on the side of the cover plate body away from the electrode assembly and sandwiched between the cover plate body and the riveting block; The cover plate assembly further includes a second sealing element, which includes a first sealing section and a second sealing section connected together. The first sealing section passes through the assembly hole and is sandwiched between the second insulating element and the plate body portion. The second sealing section is sandwiched between the cover plate body and the plate body portion. A gap is formed between the second sealing section and the first insulating element, and the gap has a minimum dimension d from the groove, satisfying d≥2mm.

2. The single-cell battery according to claim 1, characterized in that, Along the thickness direction, the groove has a thickness dimension h, and the first seal in the uncompressed state has a thickness dimension H, satisfying 0.15≤(Hh) / H≤0.45; The cross-section of the groove has a width dimension w, which satisfies 1≤w / h≤3; The groove has a cross-sectional area S1, and the first seal in the uncompressed state has a cross-sectional area S2, satisfying: 0.8≤S1 / S2≤1.

2.

3. The single-cell battery according to claim 1, characterized in that, The groove has a minimum dimension c at its distance from the outer edge of the plate body, satisfying c≥0.5mm.

4. The single-cell battery according to claim 1, characterized in that, The first seal is made of rubber.

5. The single-cell battery according to claim 1, characterized in that, The cross-section of the first seal is any one of a circle, annular, elliptical, or rectangular shape.

6. A battery pack, characterized in that, Includes the single-cell battery as described in any one of claims 1 to 5.

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