Battery and battery pack
By designing the embedded and covered parts of the battery cover, controlling their thickness ratio, and setting grooves, the problem of heat dissipation during battery welding was solved, effectively reducing internal heat and ensuring welding quality, thereby improving battery safety and energy density.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2026-03-31
AI Technical Summary
In existing technologies, the heat generated during the welding process of the battery cover and casing cannot be dissipated in time, resulting in excessively high internal battery temperatures, which can damage the battery cells. Furthermore, the heat cannot be dissipated in time during the charging and discharging process, which can easily lead to thermal runaway and affect the safety performance of the battery.
Design a battery cover plate including an embedded part and a covering part. The thickness of the embedded part is greater than that of the covering part, and the covering part is provided with a groove. By controlling the thickness ratio of the embedded part and the covering part and the setting of the groove, the heat dissipation effect is improved, the heat transfer to the battery interior is reduced, and the welding quality and battery energy density are ensured.
It effectively reduces heat transfer to the battery interior during the welding process, avoids cell damage, improves battery heat dissipation and safety, and ensures battery welding quality and energy density.
Smart Images
Figure CN224067751U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to battery technology field, concretely relates to battery and battery package. BACKGROUND
[0002] The battery generally includes a battery internal structure and a battery external structure, the battery external structure generally includes a shell and a battery cover plate, the shell and the battery cover plate are enclosed to form an enclosed space, the battery internal structure includes a battery cell, and the battery cell is arranged in the enclosed space. The shell and the battery cover plate are usually connected in an inclined welding manner, and a large amount of heat is generated during the welding process. If the heat is not dissipated in time, the internal temperature of the battery is likely to be too high, affecting the performance of the battery. Especially for a steel shell, the melting point of steel is high, and a large amount of heat is required for welding. The heat is transferred to the internal battery cell, which is likely to cause damage to the battery cell. Moreover, during the charging and discharging process of the battery, if the battery cell generates too much heat and the heat cannot be dissipated in time, the battery is likely to cause thermal runaway, affecting the safety performance of the battery. SUMMARY
[0003] Therefore, the utility model provides a kind of battery and battery package to solve the heat generated during the welding process of battery cover plate and shell in prior art cannot be dissipated in time, the internal temperature of battery is too high, causes battery cell damage, and during the charging and discharging process of battery, battery cell generates too much heat, and heat cannot be dissipated in time, battery is likely to cause thermal runaway, affects the safety performance of battery.
[0004] In a first aspect, the utility model provides a kind of battery, comprising:
[0005] Shell, the shell is steel, at least one end of the shell has opening;
[0006] Battery cover plate, the battery cover plate blocks the opening and is welded with the shell to form weld mark, and the battery cover plate and the shell are enclosed to form containing space;
[0007] Battery cell, arranged in the containing space;
[0008] Wherein, the battery cover plate includes cover plate body, and the cover plate body is steel, and the cover plate body includes body structure and cover portion, the cover portion is arranged around the body structure, the body structure includes embedded portion, the embedded portion is used to extend into shell interior from the opening, the cover portion and the opening face of the shell at least partially overlap, along the thickness direction of the battery cover plate, the thickness of the embedded portion is a, the thickness of the cover portion is b, satisfies a>b;
[0009] The recess is formed on one side of the embedding portion away from the covering portion along the thickness direction of the battery cover plate, and the embedding portion is formed with a remaining part around the recess, and the width of the remaining part along the length direction of the battery cover plate is d, satisfying 0.2mm≤d≤1.5mm.
[0010] The thickness of the single-layer pole piece is m, the number of layers of the pole piece is n, and m*n≥10mm is satisfied, 0.25≤b / a≤0.65 is satisfied, and the battery cell further comprises a diaphragm, and the diaphragm is stacked between the two adjacent pole pieces.
[0011] The covering portion has a small thickness, and the heat generated by the welding of the battery cover plate and the shell can be quickly dissipated through the covering portion, thereby improving the heat dissipation effect of the battery. In addition, by providing the recess in the covering portion, the recess serves as an air layer, and the heat conduction capacity of air is poorer than that of metal. Therefore, the heat generated by the welding of the battery cover plate and the shell is less likely to be transmitted to the inside of the battery, thereby reducing the heat transmitted to the inside of the battery, avoiding the over-high temperature in the inside of the battery, and further avoiding the damage of the battery cell. In addition, the heat generated during the charging and discharging process of the battery can be quickly dissipated through the covering portion, thereby improving the heat dissipation capacity of the battery itself and ensuring the safety of the battery. At the same time, the embedding portion has a large thickness, and the path of the heat generated by the welding of the battery cover plate and the shell to the inside of the battery is long, thereby further reducing the heat transmitted to the inside of the battery. In addition, if the value of b / a is too large, that is, the value of a is too small and / or the value of b is too large, when the value of a is too small, that is, the embedding portion is too thin, there is a risk that the embedding portion will be welded through during the inclined welding process. In addition, the cover plate body and the shell are both made of steel, and more heat is required for the welding of the battery cover plate and the shell, which will further increase the risk that the embedding portion will be welded through and the heat generated by the welding will be easily transmitted to the inside of the battery to cause damage to the battery cell. When the value of b is too large, that is, the covering portion is too thick, the heat dissipation capacity of the covering portion is weakened, the heat generated by the welding cannot be dissipated in time, and the heat transmitted to the inside of the battery is increased. If the value of b / a is too small, that is, the value of a is too large and / or the value of b is too small, when the value of a is too large, that is, the embedding portion is too thick, the embedding portion occupies too much space in the inside of the shell, thereby reducing the energy density of the battery. When the value of b is too small, that is, the covering portion is too thin, there is a risk that the covering portion will be welded through during the welding process. Therefore, the value of the ratio of the thickness a of the embedding portion to the thickness b of the covering portion b / a is controlled, so as to ensure the welding quality of the battery cover plate and the shell, the heat dissipation capacity of the battery cover plate, and the energy density of the battery.
[0012] In a second aspect, the utility model further provides a battery pack, which comprises the above-mentioned battery. BRIEF DESCRIPTION OF DRAWINGS
[0013] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings required to be used in the description of the specific embodiments or the prior art will be briefly introduced as follows. Obviously, the drawings described in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.
[0014] Figure 1 A cross-sectional structure schematic view of a cover plate body in a length direction and a thickness direction of an embodiment of the present application;
[0015] Figure 2 A cross-sectional structure schematic view of another cover plate body in a length direction and a thickness direction of an embodiment of the present application;
[0016] Figure 3 A cross-sectional structure schematic view of a cover plate body and a shell after assembly shown in FIG. Figure 1
[0017] Figure 4 An enlarged schematic view of A in FIG. Figure 3
[0018] Figure 5 A structure schematic view of a battery cover plate, a shell, an electric core and a pole assembly of an embodiment of the present application;
[0019] Figure 6 A structure schematic view of a battery cover plate, a shell and an electric core of another embodiment of the present application;
[0020] Figure 7 A structure schematic view of a battery cover plate, a shell and a pole assembly of still another embodiment of the present application;
[0021] Figure 8 A welding structure schematic view of a battery cover plate and a shell of an embodiment of the present application.
[0022] Explanation of reference signs:
[0023] 1, cover plate body; 11, embedded part; 111, groove; 112, remaining part; 12, covering part; 13, connecting part; 2, shell; 21, side wall; 22, top wall; 3, electric core; 31, electric core body; 32, tab; 4, pole assembly; 5, welding mark. Specific embodiments
[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model below. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model.
[0025] The embodiments of the utility model will be described below in combination with Figures 1 to 8
[0026] According to the embodiments of the utility model, on the one hand, a battery is provided, comprising: a shell, the shell is steel, at least one end of the shell has an opening; a battery cover plate, the battery cover plate blocks the opening and is welded with the shell to form a welding mark, the battery cover plate and the shell enclose to form an accommodation space; an electric core, arranged in the accommodation space.
[0027] The battery cover plate comprises a cover plate body 1, which is steel, and the cover plate body 1 comprises a body structure and a covering part 12, the covering part 12 is arranged around the body structure, the body structure comprises an embedded part 11, the embedded part 11 is used to extend into the inside of the shell 2 from the opening, the covering part 12 at least partially overlaps with the opening surface of the shell 2, along the thickness direction of the battery cover plate, the thickness of the embedded part 11 is a, the thickness of the covering part 12 is b, a > b is satisfied, and 0.15 ≤ b / a ≤ 0.9.
[0028] Optionally, the value of b / a can be any value in 0.15, 0.2, 0.25, 0.28, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9 and a value between any two values.
[0029] The battery cover plate of the embodiment makes the covering part 12 have a smaller thickness, the heat generated by the welding of the battery cover plate and the shell 2 can be quickly dissipated through the covering part 12, the heat dissipation effect of the battery is improved, so that the heat transferred to the inside of the battery is reduced, the temperature in the inside of the battery is prevented from being too high, and the electric core 3 is prevented from being damaged; at the same time, the embedded part 11 has a larger thickness, the path of the heat generated by the welding of the battery cover plate and the shell 2 to the inside of the battery is longer, and the heat transferred to the inside of the battery is further reduced.
[0030] It should be noted that if the value of b / a is too large, that is, if the value of a is too small and / or the value of b is too large, and if the value of a is too small, that is, if the embedded part 11 is too thin, there is a risk of welding through the embedded part 11 during the tilting welding process. Furthermore, since both the cover plate body 1 and the shell 2 are made of steel, welding the battery cover plate and shell 2 requires more heat, which also increases the risk of welding through the embedded part 11. Simultaneously, the heat generated during welding is more easily transferred to the inside of the battery, causing damage to the cell 3. If the value of b is too large... In other words, if the cover portion 12 is too thick, its heat dissipation capacity will be weakened, and the heat generated during welding cannot be dissipated in time, resulting in an increase in the heat transferred to the battery. If the value of b / a is too small, that is, if the value of a is too large and / or the value of b is too small, when the value of a is too large, that is, if the embedded portion 11 is too thick, the embedded portion 11 occupies too much space inside the casing 2, resulting in a decrease in battery energy density. When the value of b is too small, that is, if the cover portion 12 is too thin, there is a risk that the cover portion 12 will be welded through during the welding process. Therefore, the value of b / a, the ratio of the thickness a of the embedded portion 11 to the thickness b of the cover portion 12, is controlled to ensure the welding quality of the battery cover and the casing 2, while also ensuring the heat dissipation capacity of the battery cover and the energy density of the battery.
[0031] For further details, please refer to Figure 4 The battery cover and housing 2 are typically welded at an angle. Figure 4 (As indicated by the arrow direction), thereby connecting the housing 2 to the covering portion 12 and the insert portion 11 of the cover body 1. Please continue reading. Figure 4 If the thickness of the embedded part 11 is too small, there is a risk of welding through the embedded part 11 during the tilting welding process. Furthermore, in this embodiment, the shell 2 is made of steel, and welding the battery cover and the shell 2 requires more heat, which also increases the risk of welding through the embedded part 11. Therefore, a > b, that is, the thickness of the embedded part 11 is greater than the thickness of the covering part 12, thereby ensuring that the embedded part 11 has sufficient thickness and avoiding welding through the embedded part 11 due to its thinness during tilting welding, thus avoiding problems such as electrolyte leakage caused by welding through the battery.
[0032] It is worth noting that in this embodiment, the battery cover is used to seal the opening of the steel casing 2, meaning the battery cover needs to be welded to the steel casing 2, and the cover body 1 is also made of steel. However, both the steel cover body 1 and the steel casing 2 have poor thermal conductivity, and steel has a relatively high melting point. Welding the battery cover and casing 2 requires more heat, and if the heat cannot dissipate in time at the weld, it can easily affect the structure of the battery cover and casing 2. Therefore, in this embodiment, by providing a thinner covering portion 12, it is easier for heat to dissipate from the weld in a timely manner, improving the heat dissipation effect.
[0033] It should be noted that, in this embodiment, as Figure 1As shown, the main body structure also includes a connecting part 13, which is stacked with the embedding part 11, and a covering part 12 is arranged around the connecting part 13. When the battery cover is assembled with the housing 2, the embedding part 11 is inserted into the housing 2, and the connecting part 13 and the covering part 12 are both located outside the housing 2. The covering part 12 and the opening surface of the housing 2 are at least partially overlapped.
[0034] It is worth noting that the open face refers to the end face of the shell with an opening.
[0035] Furthermore, in this embodiment, the covering portion 12 is arranged around the periphery of the main body structure. This arrangement makes the heat dissipation of the battery cover more uniform and avoids excessive local heat concentration.
[0036] Of course, in other alternative embodiments, the covering portion 12 may also be provided around the body structure but not around it (i.e., partially around the body structure), for example, the covering portion 12 may be provided at both ends of the body structure along the length direction.
[0037] In one embodiment, such as Figure 1 As shown, along the length of the battery cover, the distance between the edge of the covering portion 12 and the edge of the embedded portion 11 is e, which satisfies 0.05mm≤e≤0.8mm. That is, along the length of the battery cover, the width of the covering portion 12 is e.
[0038] It is worth noting that if the value of e is too large, the edge of the cover 12 may extend beyond the housing 2, causing the side of the battery cover to protrude from the housing 2, affecting the overall quality of the battery and subsequent battery assembly. If the value of e is too small, the heat dissipation area of the cover 12 will decrease, resulting in a reduction in the heat dissipation capacity of the cover 12, affecting the heat dissipation effect, and also affecting the welding penetration of the battery cover and housing 2. In other words, the penetration depth will decrease, and in order to ensure the welding effect, the weld width needs to be increased. However, increasing the weld width will increase the risk of laser damage to the cell 3 during welding. Therefore, by controlling the value of e within an appropriate range, sufficient heat dissipation area can be achieved, while ensuring the welding reliability of the battery cover and housing 2.
[0039] In one embodiment, the thickness 'a' of the embedded part 11 ranges from 0.3mm ≤ a ≤ 1mm, and the thickness 'b' of the covering part 12 ranges from 0.1mm ≤ b ≤ 0.9mm. This configuration ensures that the thicknesses of both the embedded part 11 and the covering part 12 have reasonable values, guaranteeing the welding quality of the battery cover and the housing 2 while also ensuring the heat dissipation capacity of the battery cover and the energy density of the battery.
[0040] In one embodiment, such as Figure 2As shown, along the thickness direction of the battery cover, the side of the embedded part 11 away from the covering part 12 has a groove 111, and the embedded part 11 surrounds the groove 111 to form a remaining part 112. Along the length direction of the battery cover, the width of the remaining part 112 is d, which satisfies 0.2mm≤d≤1.5mm and 0.25≤b / a≤0.8.
[0041] By providing a groove 111 in the cover portion 12, the groove 111 acts as an air layer. Air has lower thermal conductivity than metal, making it less likely for the heat generated during the welding of the battery cover and casing 2 to be transferred to the battery interior. This allows for a relatively smaller thickness of the embedded portion 11 and a relatively larger thickness of the cover portion 12. While ensuring that the heat generated during the welding of the battery cover and casing 2 does not damage the battery cell 3, it also reduces the space occupied by the embedded portion 11 within the casing 2, increasing the battery energy density and further preventing the cover portion 12 from being welded through. Simultaneously, the smaller the width of the remaining portion 112, i.e., the larger the area of the groove 111, the larger the volume of the air layer, making it less likely for the heat generated during the welding of the battery cover and casing 2 to be transferred to the battery interior. However, if the width of the remaining portion 112 is too small, it is more likely to cause weld penetration during welding, affecting the structural strength of the cover body 1. Furthermore, since electrolyte needs to be injected into the battery, if the remaining portion 112 is welded through, the risk of electrolyte leakage increases. Therefore, in this example, the value of the width d of the remaining part 112 is limited to reduce the heat conduction capacity of the battery cover to the inside while ensuring the welding quality of the battery cover and the housing 2 as well as the structural strength of the battery cover.
[0042] It should be noted that the width of the remaining portion 112 can be the same or different at different positions. This can be set according to actual needs, as long as the width of the remaining portion 112 at each position satisfies 0.2mm ≤ d ≤ 1.5mm. For example, please refer to [link / reference]. Figure 2 The width of the remaining portion 112 on the left side of the groove 111 and the width of the remaining portion 112 on the right side of the groove 111 can be the same or different.
[0043] It is worth noting that, for the battery cover, the direction closer to housing 2 is defined as "inner," and the direction farther from housing 2 is defined as "outer." Therefore, please refer to [link / reference needed]. Figure 2 The outer side of the insert 11 is connected to the inner side of the connecting part 13. The side of the insert 11 away from the covering part 12 is the inner side of the insert 11. The groove 111 is opened outward from the inner side of the insert 11.
[0044] In one embodiment, such as Figure 5As shown, the battery cell 3 includes a positive electrode sheet, a separator and a negative electrode sheet stacked together. Along the thickness direction of the battery cover, the distance between the separator and the side of the embedded part 11 away from the covering part 12 is f, which satisfies 0.5mm≤f≤8mm.
[0045] It is worth noting that if the value of f is too small, the distance between the cover plate body 1 and the cell 3 will be too close, and the heat generated by welding the battery cover plate and the casing 2 will be easily transferred to the cell 3. When the separator is heated, it will shrink, which may cause a short circuit between the positive and negative electrodes. If the value of f is too large, the distance between the cover plate body 1 and the cell 3 will be too large, resulting in a waste of internal space in the battery and affecting the energy density of the battery.
[0046] It should be noted that the size of the separator needs to be larger than the size of the positive and negative electrode plates in order to completely isolate the positive and negative electrode plates and avoid short circuits caused by contact between the positive and negative electrode plates. Therefore, the edge of the separator is closer to the embedded part 11 than the edges of the positive and negative electrode plates.
[0047] Furthermore, such as Figure 5 As shown, the cover plate body 1 is provided with a terminal post assembly 4, and the battery cell 3 includes a cell body 31 and a tab 32. The tab 32 is led out from the cell body 31 and is located on the side of the cell body 31 facing the cover plate body 1. The tab 32 is electrically connected to the terminal post assembly 4, satisfying 0.5mm≤f≤6mm. With this arrangement, the heat generated by welding the battery cover plate and the casing 2 can be assisted in heat dissipation through the terminal post assembly 4 and the tab 32, reducing the heat transferred to the battery cell 3. Therefore, the distance between the cover plate body 1 and the battery cell 3 can be set smaller, further improving the energy density of the battery.
[0048] It is worth noting that the terminal assembly 4 serves as the current output terminal, used for electrical connection with the tab 32 of the battery cell 3, and also for electrical connection with the external busbar to achieve current transmission. The terminal assembly 4 can be the terminal body itself, with the tab 32 directly connected to the terminal body; alternatively, the terminal assembly 4 can consist of the terminal body and an adapter plate, with the tab 32 welded to the adapter plate, and the adapter plate welded to the terminal body. In other words, the tab 32 and the terminal body are indirectly electrically connected through the adapter plate.
[0049] In one embodiment, such as Figure 5 As shown, the tabs 32 include a positive tab 32 and a negative tab 32, which are led out from the same side of the cell body 31, satisfying 0.5mm≤f≤5mm. With this configuration, both the positive and negative tabs 32 can be used for heat dissipation, thus allowing for a smaller distance between the cover plate body 1 and the cell 3, further improving the battery's energy density.
[0050] It should be noted that in other alternative implementation methods, such as Figure 6As shown, the cover plate body 1 is provided with an electrode assembly 4, and the battery cell 3 includes a battery cell body 31 and an electrode tab 32. The electrode tab 32 extends from the length direction of the battery cell body 31 and is electrically connected to the electrode assembly 4, satisfying 1mm≤f≤7mm. At this time, as... Figure 6 As shown, the tabs 32 are led out from both ends of the cell body 31 along its length. That is, the tabs 32 are located on the side of the cell body 31 facing the side wall 21 of the housing 2. The pole assembly 4 is located on the cover body 1. The tabs 32 are connected to the pole assembly 4 through the adapter piece, resulting in a long heat dissipation path and poor heat dissipation effect. Therefore, it is necessary to appropriately increase the distance between the cover body 1 and the cell 3 to reduce heat transfer.
[0051] It is worth noting that the length direction of the cell body 31 is the same as the length direction of the battery cover.
[0052] In one embodiment, the electrode assembly 4 includes an electrode body, and the end face area of the electrode body on the side away from the battery cell 3 is S, satisfying S≥100mm². 2 0.28≤b / a≤0.85. The heat generated by cell 3 can be dissipated through the terminals. When the end face area of the terminals is larger, the heat dissipation area increases, which is more conducive to heat dissipation. Therefore, the value range of b / a can be further controlled, further ensuring the welding quality of the battery cover and the casing 2, and at the same time, further improving the energy density of the battery.
[0053] In one embodiment, such as Figure 3 and Figure 4 As shown, the housing 2 includes a sidewall 21, which is welded to the cover plate body 1. The wall thickness of the sidewall 21 is c, satisfying c≥0.2mm and 0.2≤b / a≤0.8. Ensuring that the thickness of the sidewall 21 is not less than 0.2mm can reduce the risk of the housing 2 deforming due to heat. However, the greater the wall thickness of the housing 2, the more heat is required for welding the battery cover plate and the housing 2, and the greater the risk of damage to the battery cell 3. Therefore, by further controlling the value of b / a within the range of 0.2 to 0.8, the heat dissipation effect can be further improved, the heat transferred to the battery interior can be reduced, and damage to the battery cell 3 can be avoided.
[0054] In one embodiment, such as Figure 3 and Figure 7 As shown, the cover plate body 1 serves as the bottom wall of the battery, and the housing 2 includes a top wall 22 disposed opposite to the cover plate body 1. The top wall 22 is provided with an electrode assembly 4, which satisfies 0.25≤b / a≤0.75.
[0055] It is worth noting that the heat generated by welding the battery cover and housing 2 cannot be dissipated through the tabs 32. Therefore, by further limiting the range of b / a, the heat dissipation effect is further improved, reducing the heat transferred to the battery interior and preventing cell damage. Furthermore, the steel housing 2 is typically open at both ends. When the battery cover in this embodiment corresponds to the bottom opening of the housing 2, the battery cover acts as the bottom wall of the battery and needs to support the cell. Therefore, the battery cover and housing 2 require greater welding strength, and more heat is generated during the welding process. Therefore, by further controlling the value of b / a within the range of 0.25 to 0.75, when the battery cover in this embodiment acts as the bottom wall of the battery, it ensures both welding strength with the housing 2 and improves heat dissipation.
[0056] It is understandable that the bottom wall of the battery is the side of the battery pack box closest to the bottom of the box when the battery is installed.
[0057] For further details, please refer to Figure 3 The side opposite to the bottom wall of the battery is the top wall 22 of the battery. In this embodiment, the top wall 22 of the battery is also a battery cover. Specifically, as shown... Figure 3 As shown, the housing 2 has openings at both opposite ends. Two battery covers are provided; one battery cover corresponds to the bottom opening of the housing 2 to serve as the bottom wall of the battery, and the other battery cover corresponds to the top opening of the housing 2 to serve as the top wall 22 of the battery. Of course, in other alternative embodiments, such as... Figure 7 As shown, the top wall 22 of the battery can also adopt other structures that can seal the opening, such as a flat plate structure.
[0058] In one embodiment, such as Figure 8 As shown, the weld width g of weld mark 5 ranges from 0.1mm to 1.5mm, and the weld depth h ranges from 0.1mm to 1.5mm. This setting ensures the connection strength between the battery cover and the casing 2.
[0059] Furthermore, the weld width of the solder mark 5 forms a first weld width i corresponding to the embedded part 11, and a second weld width j corresponding to the covering part 12, where i > j.
[0060] In one embodiment, the battery cell 3 includes multiple layers of electrode sheets stacked together. The thickness of a single electrode sheet is m, and the number of electrode sheets is n, satisfying m×n≥10mm and 0.2≤b / a≤0.65. The greater the thickness of a single electrode sheet and / or the more electrode sheets there are, the more heat the battery cell 3 generates. Therefore, by further controlling the value of b / a within the range of 0.2 to 0.65, the heat dissipation effect of the battery cover is further improved.
[0061] Furthermore, the battery cell 3 also includes a separator, which is stacked between two adjacent electrode layers. During battery charging and discharging, heat is generated, and the separator is prone to shrinkage and deformation due to heat, potentially leading to a short circuit between the positive and negative electrodes. In this embodiment, the value of b / a is further controlled, allowing the heat generated during charging and discharging to be quickly dissipated through the cover portion 12, improving the battery's heat dissipation capacity and ensuring battery safety.
[0062] In summary, in this embodiment, when the width d of the remaining portion satisfies 0.2mm≤d≤1.5mm, the thickness m of the single-layer electrode and the number of electrode layers n satisfy m×n≥10mm, the thickness a of the embedded portion and the thickness b of the covering portion satisfy 0.25≤b / a≤0.65.
[0063] It should be noted that when both the cover plate body 1 and the shell 2 are made of stainless steel, the ratio 0.2 ≤ b / a ≤ 0.9 is satisfied. When both the cover plate body 1 and the shell 2 are made of nickel-plated steel, the ratio 0.15 ≤ b / a ≤ 0.7 is satisfied. Different steels have different melting points during welding. The higher the melting point, the greater the heat required for welding the battery cover plate and shell 2. Therefore, for different steel materials, by further limiting the range of b / a values, heat dissipation can be achieved while ensuring the reliability of the welding between the cover plate body 1 and the shell 2.
[0064] It should be further explained that stainless steel is an alloy material, mainly composed of iron, chromium, nickel, and trace amounts of other elements. Chromium is the essential element that gives stainless steel its corrosion resistance, providing it with anti-oxidation and anti-corrosion properties, enabling it to resist the erosion of most chemical media, and also giving it a long service life. The corrosion resistance of stainless steel depends on the alloying elements contained in the steel, and it has good mechanical properties and wear resistance. The melting point range of stainless steel is 1100℃ to 1510℃. Nickel-plated steel parts are metal products with ordinary steel as the base material, on which a layer of nickel is plated through an electroplating process. The melting point range of nickel-plated steel is 1300℃ to 1510℃.
[0065] It is worth noting that the separator is disposed between the positive electrode and the negative electrode. The positive electrode, the negative electrode, and the separator are formed into the battery cell 3 by winding or stacking. The positive electrode includes a positive current collector and a positive active material layer, and the negative electrode includes a negative current collector and a negative active material layer. There are no particular limitations on the positive current collector, as long as it is conductive and will not cause adverse chemical changes in the battery. It can be made of materials such as stainless steel, aluminum, nickel, titanium, sintered carbon, or aluminum or stainless steel that has undergone one of the surface treatments of carbon, nickel, titanium, silver, etc. The negative current collector can be made of copper, stainless steel, nickel, titanium, etc., and a composite current collector can also be used. A composite current collector refers to a polymer layer in the middle, with metal layers disposed on opposite sides of the polymer layer. The metal layers can be made of materials such as copper, stainless steel, nickel, titanium, etc. In a specific embodiment, the positive current collector can be made of aluminum, and the negative current collector can be made of copper. The positive electrode active material layer includes positive electrode active materials, such as nickel-cobalt-manganese ternary materials, lithium iron phosphate materials, and lithium manganese iron phosphate materials; the negative electrode active material layer includes negative electrode active materials, such as artificial graphite, natural graphite, and silicon-based materials.
[0066] According to an embodiment of the present invention, in another aspect, a battery pack is also provided, including the battery described above.
[0067] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A battery, characterized by, The application relates to a battery cover plate and a battery. The battery cover plate comprises a cover plate body (1) made of steel, wherein the cover plate body (1) comprises a body structure and a cover part (12) arranged around the body structure, the body structure comprises an embedded part (11) used for extending into the inside of the shell (2) from the opening, the cover part (12) at least partially overlaps the opening surface of the shell (2), the thickness of the embedded part (11) is a, the thickness of the cover part (12) is b, and a > b is met along the thickness direction of the battery cover plate. The embedded part (11) is provided with a groove (111) on the side away from the cover part (12) along the thickness direction of the battery cover plate, and the embedded part (11) is formed with a remaining part (112) around the groove (111), the width of the remaining part (112) is d along the length direction of the battery cover plate, and 0.2mm <= d <= 1.5mm is met. The battery core (3) comprises a plurality of layers of electrode sheets arranged in a stack, the thickness of a single layer of electrode sheets is m, the number of layers of electrode sheets is n, m * n >= 10mm is met, 0.25 <= b / a <= 0.65 is met, and the battery core (3) further comprises a diaphragm arranged between two adjacent layers of electrode sheets. The distance between the edge of the cover part (12) and the edge of the embedded part (11) along the length direction of the battery cover plate is e, and 0.05mm <= e <= 0.8mm is met. The cover part (12) is arranged around the circumference of the body structure. The thickness a of the embedded part (11) is 0.3mm <= a <= 1mm, and the thickness b of the cover part (12) is 0.1mm <= b <= 0.9mm.
2. The battery of claim 1, wherein, The battery core (3) comprises a positive electrode sheet, a diaphragm and a negative electrode sheet arranged in a stack, and the distance between the diaphragm and the side of the embedded part (11) away from the cover part (12) along the thickness direction of the battery cover plate is f, and 0.5mm <= f <= 8mm is met.
3. The battery according to claim 1 or 2, characterized in that, The cover plate body (1) is provided with a pole assembly (4), the battery core (3) comprises a battery core body (31) and a tab (32), the tab (32) is led out from the battery core body (31), the tab (32) is arranged on the side of the battery core body (31) facing the cover plate body (1), the tab (32) is electrically connected with the pole assembly (4), and 0.5mm <= f <= 6mm is met.
4. The battery according to claim 1 or 2, characterized by The tab (32) comprises a positive tab (32) and a negative tab (32), the positive tab (32) and the negative tab (32) are led out from the same side of the battery core body (31), and 0.5mm <= f <= 5mm is met.
5. The battery of claim 1, wherein, 6. The battery of claim 5, wherein, 7. The battery of claim 6, wherein, 8. The battery of claim 5, wherein, The cover plate body (1) is provided with a pole assembly (4), the electric core (3) comprises an electric core body (31) and a tab (32), the tab (32) is led out from the length direction of the electric core body (31), the tab (32) is electrically connected with the pole assembly (4), and 1mm≤f≤7mm is met.
9. The battery according to claim 6 or 8, characterized in that, The pole column assembly (4) comprises a pole column body, an end face area of the pole column body away from the side of the electric core (3) is S, and S≥100mm 2 , 0.28≤b / a≤0.
85.
10. The battery of claim 1, wherein, The cover plate body (1) and the shell (2) are both stainless steel materials, 0.2≤b / a≤0.9 is met, or, The cover plate body (1) and the shell (2) are both nickel-plated steel materials, 0.15≤b / a≤0.7 is met.
11. The battery of claim 1, wherein, The shell (2) comprises a side wall (21), the side wall (21) is welded with the cover plate body (1), the wall thickness of the side wall (21) is c, 0.2mm≤c≤0.8mm is met, and 0.2≤b / a≤0.8 is met.
12. The battery of claim 1, wherein, The cover plate body (1) is used as the bottom wall of the battery, the shell (2) comprises a top wall (22) oppositely arranged with the cover plate body (1), the top wall (22) is provided with a pole assembly (4), and 0.25≤b / a≤0.75 is met.
13. The battery of claim 1, wherein, The fusion width g of the welding mark (5) is 0.1mm≤g≤1.5mm, and the fusion depth h of the welding mark (5) is 0.1mm≤h≤1.5mm.
14. The battery of claim 13, wherein, The fusion width of the welding mark (5) corresponds to the first fusion width i of the embedding part (11) and the second fusion width j of the covering part (12), and i>j is met.
15. A battery pack, characterized by The battery comprises the battery of any one of claims 1-14.