Single battery and battery pack

Abstract

The invention discloses a single battery and a battery pack, and belongs to the technical field of batteries. Each 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 part and a first sealing part, and the cover plate body is provided with an assembling hole; the pole column comprises a column body part and a plate body part which are arranged in the thickness direction and connected, the column body part penetrates through the assembly hole, the plate body part is located on the side, facing the electrode assembly, of the cover plate body, a groove is formed in the side, facing the cover plate body, of the plate body part, and the groove surrounds the column body part; the first insulating part 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 electrolyte is prevented from entering the assembly gap between the column body part and the first insulating part from the gap between the plate body part and the first insulating part through the first sealing part, so that the short-circuit risk of the single battery is reduced, and the safety of the single battery is improved.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a single cell and a battery pack. Background Art

[0002] During the assembly process of the cover assembly in the single battery, the insulation and sealing assembly between the pole and the cover body is achieved by compressing the sealing ring. However, during the injection process, the assembly gap between the sealing ring and the lower plastic poses a safety hazard, affecting the quality and service life of the battery. Summary of the invention

[0003] Purpose of the invention: An embodiment of the present application provides a single cell battery, aiming to overcome the current technical problem of potential safety hazards in the assembly gap between the sealing ring and the first insulating member; another purpose of the embodiment of the present application is to provide a battery pack.

[0004] Technical solution: A single cell disclosed in an embodiment of the present application includes: a cover plate assembly and an electrode assembly, wherein the electrode assembly is arranged on one side of the cover plate assembly in a thickness direction;

[0005] The cover plate assembly comprises:

[0006] The cover plate body is provided with an assembly hole;

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

[0008] A first insulating member, sandwiched between the plate body and the cover body;

[0009] The first sealing member is embedded in the groove and sandwiched between the first insulating member and the plate body.

[0010] In some embodiments, along the thickness direction, the groove has a thickness dimension h, and the first sealing member has a thickness dimension H, satisfying 0.15≤(Hh) / H≤0.45;

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

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

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

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

[0015] In some embodiments, the cover plate assembly further includes a rivet block disposed on a side of the cover plate body away from the electrode assembly and connected to the column portion, and the rivet block and the plate portion jointly clamp the cover plate body.

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

[0017] In some embodiments, the cover assembly also includes a second seal, the second seal includes a first sealing segment and a second sealing segment connected to each other, the first sealing segment is passed through the assembly hole and clamped between the second insulating member and the plate body, and the second sealing segment is clamped between the cover body and the plate body.

[0018] In some embodiments, a gap is formed between the second sealing section and the first insulating member, and the gap has a minimum dimension d from the groove, satisfying d≥2 mm.

[0019] In some embodiments, the cross-section of the first seal is any one of circular, annular, elliptical or rectangular.

[0020] An embodiment of the present application also provides a battery pack, comprising a single cell as described in the above embodiment.

[0021] Beneficial effects: The single cell of the embodiment of the present application 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; the cover plate assembly comprises a cover plate body, a pole, a first insulating member and a first sealing member, wherein the cover plate body is provided with an assembly hole; the pole comprises a column portion and a plate portion arranged and connected in the thickness direction, wherein the column portion is provided with an assembly hole, wherein the plate portion is located on the side of the cover plate body facing the electrode assembly, wherein the plate portion is provided with a groove on the side of the cover plate body facing the cover plate body, wherein the groove surrounds the column portion; the first insulating member is sandwiched between the plate portion and the cover plate body; the first sealing member is embedded in the groove and sandwiched between the first insulating member and the plate portion. By providing a groove on the side of the plate portion of the pole 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 column portion and the first insulating member through the gap between the plate portion and the first insulating member, thereby preventing the electrolyte from conducting the pole and the cover plate body, causing a short circuit of the single cell, and improving the safety of the single cell.

[0022] The battery pack of the embodiment of the present application includes the single cell as described in the above embodiment, and thus can have all the technical features and technical effects of the above single cell, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a schematic diagram of the three-dimensional structure of a cover plate assembly in a single cell according to an embodiment of the present application;

[0025] Figure 2 This is a schematic diagram of a top view of a cover plate assembly in a single cell according to an embodiment of the present application;

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

[0027] Figure 4 for Figure 2 Schematic cross-sectional view in the middle BB direction;

[0028] Figure 5 This is a schematic diagram of the three-dimensional structure of the pole in the cover plate assembly of the embodiment of the present application;

[0029] Figure 6 This is a schematic diagram of the top view of the pole in the cover plate assembly of the embodiment of the present application;

[0030] Figure 7 This is a schematic diagram of the structure of the first sealing member in the cover plate assembly of an embodiment of the present application;

[0031] Figure numerals: 1, cover plate assembly; 11, cover plate body; 110, assembly hole; 12, pole; 121, column part; 122, plate body; 1220, groove; 13, first insulating member; 14, first sealing member; X, thickness direction; 1221, outer edge; 15, second sealing member; 151, first sealing section; 152, second sealing section; 10, gap; 16, rivet block; 17, second insulating member. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0033] In the description of the present application, it should be understood that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "multiple" means two or more, and at least one means one, two or more, unless otherwise clearly and specifically limited. The terms "first", "second", "third", etc. are only used to name the parts or embodiments with numbers for the convenience of description, and do not imply that there is an order of importance between the parts or embodiments.

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

[0035] As the preamble of the embodiment of the present application, during the assembly process of the cover assembly in the single cell, the insulation and sealing assembly of the pole and the cover body are achieved by compressing the sealing ring. However, during the injection process, there is a safety hazard in the assembly gap between the sealing ring and the lower plastic, which affects the quality and service life of the battery. For example, after the battery is assembled, it is necessary to inject liquid. During the injection process, it is inevitable that part of the electrolyte will enter the assembly gap between the lower plastic and the sealing ring along the gap between the cover body and the lower plastic, thereby causing the electrolyte to conduct the pole and the cover body, and the resistance of the entire negative electrode of the battery is reduced, which in turn affects the side voltage at the negative electrode of the battery, causing the battery to corrode, leak and fail, and ultimately cause a short circuit in the single cell. During the use of the battery, a short circuit may cause serious safety problems such as overheating, fire or even explosion.

[0036] In view of this, an embodiment of the present application provides a single cell battery, aiming to solve at least one of the above-mentioned technical problems.

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

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

[0039] See also Figure 3As shown, in some embodiments, along the thickness direction X, the groove 1220 has a thickness dimension h, and the first seal 14 in the uncompressed state has a thickness dimension H, which satisfies 0.15≤(Hh) / H≤0.45; the cross section of the groove 1220 has a width dimension w, which satisfies 1≤w / h≤3; the groove 1220 has a cross-sectional area S1, and the cross-sectional area of ​​the first seal 14 in the uncompressed state is S2, which satisfies: 0.8≤S1 / S2≤1.2. It should 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 the 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 122 is enhanced, the leakage of the electrolyte inside the battery is effectively prevented, and the stability of the chemical environment inside the battery is maintained.

[0040] Specifically, (Hh) / H can be any value among 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 may not be able to tightly fill the gap 10 between the groove 1220 and the surrounding components, resulting in poor sealing effect and the electrolyte is easy to seep out of the gap. If the compression amount is too large, on the one hand, it will cause excessive deformation of the first seal 14, which may damage the structure of the first seal 14 and reduce its service life. On the other hand, excessive pressure may cause the first seal 14 to squeeze 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, the ratio between the cross-sectional area of ​​the groove 1220 and the cross-sectional area of ​​the first seal 14 is between 0.8 and 1.2, ensuring that the first seal 14 can be in an optimal filling state in the groove 1220. When the ratio of width to thickness is appropriate, the first seal 14 can evenly distribute the pressure in the groove 1220 and better fit the wall of the groove 1220. The reasonable ratio of the cross-sectional area ensures that the first seal 14 can completely fill the groove 1220 without partial vacancies or overfilling, 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 among 1, 1.5, 2, 2.5, 3, or a range value between any two values. Specifically, S1 / S2 can be any value among 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 may not be completely installed in the groove 1220. Part of the material of the first seal 14 will be squeezed outside the groove 1220, resulting in uneven distribution of the first seal 14 around the groove 1220. During the assembly and use of the battery, it is easy to produce gaps where the first seal 14 is not in close contact with the edge of the groove 1220. If S1 / S2 is greater than 1.2, the cross-sectional area of ​​the groove 1220 is much larger than the cross-sectional area of ​​the first seal 14, and the first seal 14 cannot completely fill the space in the groove 1220, and there will be more gaps. During the operation of the battery, the electrolyte may enter these gaps, and because the first seal 14 cannot fit tightly against the wall of the groove 1220, it cannot effectively prevent the electrolyte from flowing in the gaps, so that the electrolyte may pass through these unsealed channels and reach the gap 10 between the main body and the first insulating member 13, thereby causing safety problems such as battery short circuit.

[0044] Furthermore, by precisely controlling the above parameters, the first seal 14 can be better fixed in the groove 1220 and will not be easily displaced. At the same time, due to the reasonable design of the compression amount and size, the first seal 14 can have a certain elastic buffer 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 effect 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, a vernier caliper, a micrometer or other measuring tool can be used to measure the corresponding dimensions of the groove 1220 and the first seal 14, and the areas S1 and S2 can be calculated using a geometric formula. H, h, w, S1 and S2 can also be measured by image processing. Alternatively, H, h, w, S1 and S2 can also be measured by projection, using a projection measurement device (such as a digital microscope or an image measuring instrument) for measurement.

[0046] Among them, the cover assembly 1 of the single battery can be disassembled, and any one of chemical analysis, physical detection, and spectral analysis can be used to detect whether electrolyte has passed through the first sealing member 14 and entered the assembly gap 10 between the pole 12 and the first insulating member 13, so as to determine whether the sealing performance between the lower plastic and the cover body 11 is satisfactory.

[0047] The test results of the embodiments are shown in the following table:

[0048]

[0049] As shown in the table above, in Examples 1 to 12, when (Hh) / 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 122 is good, and there is no electrolyte leakage in the assembly gap 10 between the pole 12 and the first insulating member 13, meeting the requirement of sealing and blocking the electrolyte. In Examples 13 to 18, when S1 / S2 is less than 0.8, at this time, the compression ratio of the first seal 14 is qualified, and the space of the groove 1220 is large, resulting in poor sealing; when S1 / S2 is greater than 1.2, at this time, the compression ratio of the first seal 14 is qualified, the space of the groove 1220 is small, and the first seal 14 is partially squeezed out, and the sealing performance deteriorates. In Examples 19 to 21, when the compression ratio of the first seal 14 is greater than 45, the compression amount of the first seal 14 is too large, and there is extrusion deformation in the contact area between the first seal 14 and the first insulating member 13, and the sealing performance is deteriorated. In Examples 22 to 24, when the compression ratio of the first seal 14 is less than 15, the compression amount is too small, and the first seal 14 may not be able to tightly fill the gap 10 between the groove 1220 and the surrounding components, resulting in poor sealing effect, and the electrolyte is easy to seep out of the gap.

[0050] See also Figure 6 As shown, in some embodiments, the groove 1220 has a minimum dimension c from the outer edge 1221 of the plate body 122, satisfying c ≥ 0.5 mm. It should be understood that by limiting the minimum spacing between the groove 1220 and the outer edge 1221 of the plate body 122, it helps to avoid the influence of edge effects. Due to factors such as material processing and assembly stress, deformation, micro cracks and other problems are more likely to occur. If the groove 1220 is too close to the outer edge 1221, the slight deformation or cracks generated in these edge areas may extend to the groove 1220 area, thereby destroying the sealing effect of the first seal 14. By setting the groove 1220 at least 0.5 mm away from the outer edge 1221, the groove 1220 area where the seal is located can be placed in a relatively stable structural area, reducing the risk of seal failure due to edge deformation or cracks.

[0051] In some embodiments, the first seal 14 is made of rubber material. It should be understood that the first seal 14 can be fluororubber with a Shore hardness between 65° and 75°, which is resistant to strong acid and alkali corrosion, especially electrolyte. After being immersed in the electrolyte, the first seal 14 has a size expansion of less than 20% and a weight of less than 30%; the rubber seal can resist the corrosion of the electrolyte, maintain its physical and chemical properties for a long time, and ensure its long-term stability in the battery; the first seal 14 is baked at a high temperature of 300°C, and there is no deformation for 2 minutes, and the insulation internal resistance of the first seal 14 is greater than 200MΩ.

[0052] See also Figure 1 , Figure 3 and Figure 4 As shown, in some embodiments, the cover plate assembly 1 further includes a rivet block 16, which is disposed on the side of the cover plate body 11 away from the electrode assembly and connected to the column portion 121, and the rivet block 16 and the plate portion 122 jointly clamp the cover plate body 11. It should be understood that by providing a tight connection between the rivet block 16 and the column portion 121, it is possible to ensure smooth conduction of current between the pole 12 and the external circuit. The rivet block 16 and the plate portion 122 jointly clamp the cover plate body 11 to form a reliable mechanical connection structure. By adopting a double-sided clamping method, the connection between the pole 12 and the cover plate body 11 is more stable, which greatly reduces the risk of the pole 12 loosening or even falling off due to external force; at the same time, during the battery charging and discharging process, the pole 12 will conduct current and will be subjected to certain thermal stress and mechanical stress. The riveting block 16 and the plate body 122 jointly clamp the cover body 11, so that the stress borne by the pole 12 can be more evenly dispersed on the cover body 11, preventing the stress from being concentrated at the connection point between the pole 12 and the cover body 11, and avoiding cracks or damage to the cover body 11 due to stress concentration, thereby extending 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 122 jointly clamp the cover body 11, the structure of the cover body 11 around the pole 12 is more compact, which helps to further enhance the insulation performance between the pole 12 and the cover body 11.

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

[0054] See also Figure 3 and Figure 4As shown, in some embodiments, the cover plate assembly 1 further includes a second sealing member 15, and the second sealing member 15 includes a first sealing segment 151 and a second sealing segment 152 connected to each other. The first sealing segment 151 is arranged in the assembly hole 110 and sandwiched between the second insulating member 17 and the plate body 122, and the second sealing segment 152 is sandwiched between the cover plate body 11 and the plate body 122. It should be understood that the first sealing segment 151 effectively fills the gap that may exist after the column body 121 passes through the assembly hole 110, prevents the electrolyte from penetrating upward from the assembly hole 110, prevents the electrolyte from contacting the area between the riveting block 16 and the second insulating member 17, and prevents electrical faults caused by electrolyte leakage. At the same time, it avoids electrical connection between the second insulating member 17 and the plate body 122 due to possible tiny conductive impurities, and further enhances the insulation performance between the pole 12 and the cover plate body 11. The second sealing section 152 is sandwiched between the cover body 11 and the plate body 122, further strengthening the sealing effect of the connection between the cover body 11 and the plate body 122. The double sealing sections work together to greatly reduce the possibility of electrolyte leakage and comprehensively guarantee the stability of the internal environment of the battery. The second seal 15 adopts a two-stage design to better adapt to these complex working conditions. The sealing sections at different positions respectively respond to pressures and displacements in different directions, always maintaining good sealing performance, and ensuring that the battery can effectively prevent electrolyte leakage under various circumstances. Furthermore, through the effective sealing of the second seal 15, the chance of electrolyte contact with other components is reduced, and the service life of components such as the second insulating member 17, the rivet block 16 and the cover body 11 is extended, thereby improving the reliability and durability of the entire battery. In addition, the two-stage structural design of the second seal 15 facilitates assembly to a certain extent.

[0055] See also 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 gap 10 has a minimum dimension d from the groove 1220, satisfying 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, it is ensured that the first seal 14 can independently play a sealing role in its working area without being affected by the second sealing segment 152, and prevent the second sealing segment 152 from interfering with the sealing effect of the first seal 14 during the use of the battery (such as when subjected to vibration, temperature changes, etc.), and maintain the relative independence of the two sealing structures of the second sealing segment 152 and the first seal 14, thereby maintaining the stability of the internal structure of the battery and extending the service life of the battery. If the gap 10 is too close to the groove 1220, the second sealing segment 152 may squeeze the area where the first seal 14 is located due to position changes, and even cause damage or deformation of structural components, destroying the tight fit between the first seal 14 and the groove 1220.

[0056] See also Figure 7 As shown, in some embodiments, the cross section of the first seal 14 is any one of a circle, annular, elliptical or rectangular. It should be understood that the first seal 14 with a circular cross section has good uniformity of force and pressure transmission. The uniform force characteristic enables the first seal 14 to maintain good stability in the groove 1220, and the wear degree of each part is relatively consistent during long-term use, which is conducive to maintaining the durability of the performance of the first seal 14. The first seal 14 with an annular cross section can more effectively utilize the space in the groove 1220. It can achieve sealing of key areas without taking up too much space, and can better cooperate with other components (such as poles 12, insulating parts, etc.) to optimize the structural layout inside the battery. The first seal 14 with an elliptical cross section can be designed according to the specific assembly space shape inside the battery. By adjusting the compression amount of the long axis and short axis direction of the elliptical first seal 14, a differentiated sealing effect can be achieved. The first seal 14 with a rectangular cross section can better fit when it contacts the planar structure and effectively fill the gap between the planes.

[0057] The present application also provides a battery pack, including a single battery as in the above embodiment. In the above embodiment, the description of each embodiment has its own emphasis. For parts not described in detail in one embodiment, please refer to the relevant description of other embodiments.

[0058] The above is a detailed introduction to a single cell and a battery pack provided in the embodiments of the present application, and the principles and implementation methods of the present application are explained by applying specific examples. The description of the above embodiments is only used to help understand the technical solution and its core idea of ​​the present application; ordinary technicians in this field should understand that: they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions 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 arranged on one side of the cover plate assembly in a thickness direction; The cover plate assembly comprises: The cover plate body is provided with an assembly hole; The pole comprises a column part and a plate part which are arranged and connected along the thickness direction, the column part is provided with the assembly hole, the plate part is located on the side of the cover plate body facing the electrode assembly, and a groove is formed on the side of the plate part facing the cover plate body, and the groove surrounds the column part; A first insulating member, sandwiched between the plate body and the cover body; The first sealing member is embedded in the groove and sandwiched between the first insulating member and the plate body.

2. The single cell according to claim 1, characterized in that: Along the thickness direction, the groove has a thickness dimension h, and the first sealing member in an 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 cross-sectional area of ​​the first sealing member in an uncompressed state is S2, satisfying: 0.8≤S1 / S2≤1.

2.

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

4. The single cell according to claim 1, characterized in that: The first sealing component is made of rubber material.

5. The single cell according to claim 1, characterized in that: The cover plate assembly further includes a rivet block, which is disposed on a side of the cover plate body away from the electrode assembly and connected to the column portion, and the rivet block and the plate portion jointly clamp the cover plate body.

6. The single cell according to claim 5, characterized in that: The cover plate assembly further includes a second insulating member, which is located on a side of the cover plate body away from the electrode assembly and is sandwiched between the cover plate body and the riveting block.

7. The single cell according to claim 6, characterized in that: The cover assembly also includes a second seal, which includes a first sealing section and a second sealing section that are connected. The first sealing section is inserted into the assembly hole and clamped between the second insulating member and the plate body, and the second sealing section is clamped between the cover body and the plate body.

8. The single cell according to claim 7, characterized in that: A gap is formed between the second sealing section and the first insulating member, and the gap has a minimum dimension d from the groove, satisfying d≥2 mm.

9. The single cell according to claim 1, characterized in that: The cross section of the first seal is any one of circular, annular, elliptical or rectangular.

10. A battery pack, characterized in that: The invention comprises a single cell according to any one of claims 1 to 9.

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