Pole piece structure and battery
By designing the four corners of the electrode as chamfered corners and setting inclined intersecting chamfered edges, the problem of the electrode piercing the separator at right angles is solved, which improves battery safety and production efficiency and reduces costs.
Patent Information
- Application Number
- CN202423322112.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2034-12-31
AI Technical Summary
In existing technologies, the right-angled structure of the electrode sheets can easily puncture the separator, leading to a short circuit inside the battery and posing a safety hazard.
The four corners of the electrode are constructed as chamfers, and the first and second chamfers are set to intersect at an angle to form a trapezoidal chamfer. By limiting the chamfer parameters B/D, B, D, θ, A, R, etc., right-angle structures are avoided, burrs are reduced, and the processing is optimized.
It improves battery safety, reduces production costs and processing difficulty, and enhances electrode durability and battery energy density.
Smart Images
Figure CN223941785U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, specifically to electrode structure and battery. Background Technology
[0002] Batteries, as a crucial component of the new energy industry, are being used more and more widely, and their safety is receiving increasing attention. Batteries mainly consist of an outer casing and an electrode assembly located inside the casing. The electrode assembly mostly uses a stacked configuration, where positive and negative electrodes are alternately stacked, with a separator between them. In current technology, the electrodes used for stacking are cut, and are typically rectangular. During the electrode manufacturing process, sharp points are formed at the four right angles of the rectangle. During subsequent battery formation and pressure testing, these right-angled structures can easily puncture the separator, causing an internal short circuit, which could potentially lead to battery fire or even explosion, resulting in poor safety. Utility Model Content
[0003] In view of this, the present invention provides an electrode structure and a battery to solve the problem that right angles on the electrode can easily puncture the separator, resulting in poor battery safety.
[0004] In a first aspect, this utility model provides an electrode structure, comprising: an electrode body and an electrode tab, the electrode tab being connected to the electrode body; the electrode body having two first sides and two second sides arranged opposite to each other; and all four corners of the electrode body being constructed as chamfered corners; a first chamfered edge and a second chamfered edge are formed on the electrode body at the chamfered corner positions, the first chamfered edge being parallel to the first side, the second chamfered edge being inclined relative to the second side, the first end of the second chamfered edge being connected to the end of the first chamfered edge away from the second side, and the intersection point between the first chamfered edge and the second chamfered edge being the first intersection point; the second end of the second chamfered edge being connected to the first side, and the intersection point between the second chamfered edge and the first side being the second intersection point; the vertical distance from the first intersection point to the second side being B, and the vertical distance from the second intersection point to the second side being D, wherein 0.15≤B / D≤0.3, 0.5mm≤B≤1.5mm.
[0005] Beneficial effects: By constructing all four corners of the electrode body as chamfered structures, the right-angle structure formed by the direct intersection of the first and second sides is avoided. This prevents sharp points formed by right angles from piercing the separator, thus avoiding short circuits between the positive and negative electrodes and improving battery safety. Furthermore, by setting chamfers, a first chamfer parallel to the first side and a second chamfer inclined relative to the second side are formed on the electrode body. The vertical distance B from the first intersection point formed by the first and second chamfers to the second side, and the vertical distance D from the second intersection point formed by the second chamfers to the second side, satisfy the relationship B < D. This makes the shape of the chamfer position trapezoidal, which is convenient for processing. At the same time, by limiting the value of B / D to the range of 0.15 to 0.3, and the value of B to the range of 0.5mm to 1.5mm, the die-cutting difficulty in the chamfering process can be reduced, the processing efficiency can be improved, the formation of right angles on the electrode body that would pierce the separator can be further avoided, and excessive material waste can be avoided, thus reducing production costs.
[0006] In one alternative embodiment, the angle between the second cut edge and the second side edge is θ, where 30°≤θ≤45°.
[0007] Beneficial effects: It facilitates die-cutting and processing, avoids material waste, and saves costs.
[0008] In one optional implementation, the vertical distance D from the second intersection point to the second side is in the range of 2mm ≤ D ≤ 6.5mm.
[0009] Beneficial effects: It facilitates die-cutting, reduces processing difficulty, avoids material waste, and saves production costs.
[0010] In one optional implementation, the vertical distance from the first cut edge to the first side edge is A, where 3mm ≤ A ≤ 5mm.
[0011] Beneficial effects: It facilitates die-cutting, reduces the risk of the electrode body's edges puncturing the separator, thereby improving battery safety, and avoids wasting materials.
[0012] In one optional implementation, the vertical distance B from the first intersection point to the second side and the vertical distance A from the first tangent to the first side satisfy the following relationship: 0.1≤B / A≤0.5.
[0013] Beneficial effects: It facilitates die-cutting and positioning, and reduces the risk of the edges and corners of the electrode body 1 puncturing the separator, thereby improving battery safety.
[0014] In one alternative embodiment, the first cut edge and the second cut edge are configured with a rounded transition, and / or the second cut edge and the first side edge are configured with a rounded transition, wherein the radius of the circle containing the rounded corner is R, where 1mm≤R≤2mm.
[0015] Beneficial effects: By setting a rounded transition between the first and second cut edges, compared with the structure where the first and second cut edges are directly connected to form a sharp corner, burrs at the sharp corners can be reduced, thus avoiding burr damage to the diaphragm. It can also reduce the phenomenon of stress concentration at the corners, reducing the risk of the electrode body breaking at the connection between the first and second cut edges. By setting the radius R of the circle containing the rounded corner to a value between 1mm and 2mm, burrs can be reduced, safety can be improved, and the phenomenon of the remaining dimension of the first cut edge along the first direction being too small can be avoided, thus ensuring the smooth progress of die-cutting positioning and ensuring the processing efficiency of the corner cutting process.
[0016] By setting a smooth transition between the second cut edge and the first side edge through a rounded corner, burrs at the connection between the second cut edge and the first side edge can be reduced, thereby avoiding damage to the diaphragm from burrs. It can also reduce stress concentration and reduce the risk of the electrode body breaking at the connection between the second cut edge and the first side edge. By setting the radius R of the circle containing the rounded corner to a value between 1mm and 2mm, burrs at the connection between the second cut edge and the first side edge can be reduced, improving safety, and avoiding material waste.
[0017] In one optional embodiment, the tab is connected to the first side, and along the extending direction of the first side, the distance between the second intersection point and the tab is E, where 5mm≤E≤30mm.
[0018] Beneficial effects: It can ensure that the distance between the electrode tab and the two chamfers at both ends of the first side is relatively reasonable, thereby avoiding accidental damage to the electrode tab during the chamfering process, reducing processing difficulty and improving processing efficiency.
[0019] In one optional embodiment, the first side is perpendicular to the second side, the vertical distance between the two first sides is L, and the vertical distance between the two second sides is W, wherein 0.1≤A / L≤0.5, 0.1≤D / W≤0.3.
[0020] Beneficial effects: It can ensure a clear corner cutting effect, avoid the sharp corners of the electrode body from piercing the separator, thereby improving battery safety, and also avoid excessive material waste.
[0021] In one optional implementation, the vertical distance L between the two first sides is in the range of 10mm ≤ L ≤ 600mm; the vertical distance W between the two second sides is in the range of 5mm ≤ W ≤ 200mm.
[0022] Beneficial effects: It helps to improve the energy density of the battery and also improves the charging and discharging performance of the battery.
[0023] Secondly, this utility model also provides a battery, including the aforementioned electrode structure. Since the battery includes an electrode structure and has the same effects as the electrode structure, it will not be described in detail here. Attached Figure Description
[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0025] Figure 1 This is a schematic diagram of a electrode structure according to an embodiment of the present utility model;
[0026] Figure 2 for Figure 1 A magnified view of part of C;
[0027] Figure 3 This is a schematic diagram of the electrode strip before cutting according to an embodiment of the present invention;
[0028] Figure 4 for Figure 3 A magnified view of part of F;
[0029] Figure 5 This is a schematic diagram showing the positional relationship between the chamfer on the electrode strip and the die-cutting tool in an embodiment of this utility model.
[0030] Figure 6 This is a partially enlarged schematic diagram of the edge of the electrode body in an embodiment of this utility model;
[0031] Figure 7 This is a partially enlarged schematic diagram of the edge of the electrode tab in an embodiment of this utility model;
[0032] Figure 8 This is a schematic diagram of the battery structure according to an embodiment of the present invention.
[0033] Explanation of reference numerals in the attached figures:
[0034] 1. Electrode body; 101. First side; 102. Second side; 103. First cut edge; 104. Second cut edge; 105. First intersection point; 106. Second intersection point; 11. Foil; 111. Burr; 12. Active material layer; 2. Tab; 3. Encapsulation film; 301. Seal; 4. Positive electrode adapter; 5. Negative electrode adapter; 6. Sealant; 7. Die-cutting tool; 701. First end face; 702. Second end face; 100. Electrode strip; 110. Die-cutting section; 120. Slitting line. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0036] The following is combined Figures 1 to 8 The following describes embodiments of the present invention.
[0037] According to embodiments of the present invention, in one aspect, an electrode structure is provided, such as... Figures 1 to 2 As shown, the electrode structure includes an electrode body 1 and electrode tabs 2. The electrode tabs 2 are connected to the electrode body 1. The electrode body 1 has two opposing first sides 101 and two opposing second sides 102. All four corners of the electrode body 1 are chamfered. A first chamfered edge 103 and a second chamfered edge 104 are formed at the chamfered corners on the electrode body 1. The first chamfered edge 103 is parallel to the first side 101, and the second chamfered edge 104 is inclined relative to the second side 102. The first end of the second chamfered edge 104 is located away from the second side 102 on the first chamfered edge 103. One end of 2 is connected, and the intersection of the first cut edge 103 and the second cut edge 104 is the first intersection point 105. The second end of the second cut edge 104 is connected to the first side edge 101, and the intersection of the second cut edge 104 and the first side edge 101 is the second intersection point 106. The vertical distance from the first intersection point 105 to the second side edge 102 is B, and the vertical distance from the second intersection point 106 to the second side edge 102 is D, where 0.15≤B / D≤0.3, 0.5mm≤B≤1.5mm.
[0038] It should be noted that before chamfering the electrode body 1, the electrode body 1 is rectangular, with the first side 101 and the second side 102 forming the sides of the rectangle. The first side 101 and the second side 102 are perpendicular to each other. Further integration... Figures 1 to 2As shown, the first side 101 extends along a first direction, and the second side 102 extends along a second direction, wherein the first direction and the second direction are perpendicular. The electrode structure can be a positive electrode or a negative electrode. During the battery assembly process, the electrodes are stacked in the order of negative electrode, separator, positive electrode, negative electrode, etc., to form an electrode group.
[0039] By constructing the four corners of the electrode body 1 as chamfered structures in this embodiment, the right-angle structure formed by the direct intersection of the first side 101 and the second side 102 is avoided. This prevents the sharp points formed by the right angle from piercing the separator, thereby avoiding short circuits between the positive and negative electrodes and improving battery safety. Furthermore, by setting the chamfers, a first chamfered edge 103 parallel to the first side 101 and a second chamfered edge 104 inclined relative to the second side 102 are formed on the electrode body 1. The first intersection point 105 formed by the intersection of the first chamfered edge 103 and the second chamfered edge 104 is perpendicular to the second side 102. The perpendicular distance B, the second intersection point 106 formed by the intersection of the second cutting edge 104 and the first side edge 101, and the vertical distance D from the second side edge 102 satisfy the relationship 0.15≤B / D≤0.3, that is, B<D, so that the shape of the cutting corner position is trapezoidal, which is convenient for processing. At the same time, by limiting B / D to the range of 0.15 to 0.3, and B to the range of 0.5mm to 1.5mm, the die-cutting difficulty in the cutting corner process can be reduced and the processing efficiency can be improved. It can also further avoid the formation of right angles on the electrode body 1 that puncture the diaphragm, and can also avoid excessive material waste and reduce production costs.
[0040] It should be noted that further integration Figures 3 to 4 As shown, the electrode structure is cut from a long strip of electrode material 100, which extends along the first direction and along the cutting line 120 (as shown). Figure 3 (As shown by the dotted line in the image) The electrode strip 100 is cut into multiple electrode structures. Before cutting, the corners on the electrode structures are machined using a die-cutting tool 7, and then further combined... Figure 5As shown, the die-cutting tool 7 used for processing the corners simultaneously processes one corner on each of two adjacent electrode structures to form a die-cutting part 110 on the electrode strip 100. Then, during electrode slitting, the die-cutting part 110 is divided into two corners on the electrode structures. By setting the die-cutting cutter 7 to have a first end face 701, the first cutting edge 103 of the cutting corner is correspondingly processed on the electrode strip 100. Even if the die-cutting cutter 7 deviates along the first direction during the die-cutting process, it can ensure that the cutting corner on each electrode structure presents a trapezoidal cutting corner form, so as to ensure the consistency of the shape of each electrode structure. However, for the traditional cutting corner on each electrode structure is a triangle, the two second end faces 702 of the die-cutting cutter 7 need to extend directly to intersect. If the die-cutting cutter 7 does not have a first end face 701, then during the die-cutting process, it is necessary to ensure accurate die-cutting positioning, that is, the intersection line of the two second end faces 702 is completely aligned with the dividing line 120 between the two electrode structures. If the die-cutting cutter 7 deviates along the first direction, the cutting corner on one of the electrode structures cannot present a triangle, and it will also increase the sharp corners on the electrode body 1, resulting in an unqualified electrode structure. Therefore, it will increase the processing difficulty and is not conducive to improving the die-cutting efficiency.
[0041] By setting the vertical distance B from the first intersection point 105 to the second side 102 and the vertical distance D from the second intersection point 106 to the second side 102 to satisfy the relationship 0.15≤B / D≤0.3, so that B<D, it is convenient for the die-cutting tool 7 to process the chamfer. The chamfer on the electrode structure is trapezoidal in shape, B corresponds to the size of the upper base of the trapezoid, and D corresponds to the size of the lower base of the trapezoid. If B / D is less than 0.15, the upper base of the trapezoid formed by the chamfer is too short relative to the lower base. In order to reduce the error of the chamfer on the two adjacent electrode structures during the die-cutting process, the accuracy of the die-cutting positioning needs to be improved, which increases the difficulty of die-cutting positioning and is not conducive to the processing efficiency during the die-cutting positioning process. If B / D is greater than 0.3, the upper base of the trapezoid is too long relative to the lower base, and the trapezoid formed by the chamfer is close to a rectangle. Then the corner formed by the intersection of the second chamfer 104 and the first side 101 is close to a right angle, and there is still a risk that the right angle structure will puncture the diaphragm.
[0042] If the vertical distance B from the first intersection point 105 to the second side 102 is less than 0.5mm, the upper base of the trapezoid formed by the cut corner is too short, which will increase the difficulty of die-cutting positioning and is not conducive to the processing efficiency during the die-cutting positioning process; if B is greater than 1.5mm, the upper base of the trapezoid formed by the cut corner is too long, and too much material needs to be cut off, resulting in material waste and increased production costs.
[0043] In one embodiment, the angle between the second cut edge 104 and the second side edge 102 is θ, where 30° ≤ θ ≤ 45°. It should be noted that if θ is less than 30°, the angle of inclination of the second cut edge 104 relative to the second side edge 102 is too small. Therefore, given a fixed vertical distance B from the first intersection point 105 to the second side edge 102, the vertical distance D from the second intersection point 106 to the second side edge 102 needs to be smaller. The angle formed by the intersection of the second cut edge 104 and the first side edge 101 is close to a right angle, still posing a risk of the right-angle structure puncturing the diaphragm and requiring high die-cutting precision, which is detrimental to die-cutting. If θ is greater than 45°, the angle of inclination of the second cut edge 104 relative to the second side edge 102 is too large, requiring excessive material to be cut away, wasting material and increasing production costs. Therefore, by setting the angle θ between the second cut edge 104 and the second side edge 102 to between 30° and 45°, it is beneficial for die-cutting and processing, while also avoiding material waste and saving costs.
[0044] In one embodiment, the vertical distance D from the second intersection point 106 to the second side 102 is in the range of 2mm ≤ D ≤ 6.5mm. It should be noted that the vertical distance D from the second intersection point 106 to the second side 102 is the lower base of the trapezoid formed by the chamfer. If D is less than 2mm, the length to be cut off from the first side 101 of the electrode body 1 is too short, increasing the difficulty of die-cutting and hindering die-cutting; if D is greater than 6.5mm, the length to be cut off from the first side 101 of the electrode body 1 is too long, wasting material. Therefore, by setting the vertical distance D from the second intersection point 106 to the second side 102 within the range of 2mm to 6.5mm, it is beneficial for die-cutting, reduces processing difficulty, avoids material waste, and saves production costs.
[0045] In one embodiment, the vertical distance from the first cut edge 103 to the first side edge 101 is A, where 3mm ≤ A ≤ 5mm. It should be noted that the vertical distance A from the first cut edge 103 to the first side edge 101 is the length to be cut off from the second side edge 102 of the electrode body 1. If A is less than 3mm, the length to be cut off from the second side edge 102 is too short, making processing difficult and hindering die-cutting. Furthermore, the corner cutting effect is not obvious, and there is still a risk of the electrode body's corners piercing the separator. If A is greater than 5mm, the length to be cut off from the second side edge 102 is too long, wasting material and hindering cost savings. Therefore, by limiting the vertical distance A from the first cut edge 103 to the first side edge 101 to between 3mm and 5mm, die-cutting is facilitated, the risk of the electrode body's corners piercing the separator is reduced, thereby improving battery safety and avoiding material waste.
[0046] In one embodiment, the vertical distance B from the first intersection point 105 to the second side 102 and the vertical distance A from the first tangent edge 103 to the first side 101 satisfy the following relationship: 0.1≤B / A≤0.5. It should be noted that the vertical distance A from the first cut edge 103 to the first side edge 101 is also the height of the trapezoid formed by the cut corner. If B / A is less than 0.1, the upper base of the trapezoid formed by the cut corner is too small relative to the height of the trapezoid, making the overall shape of the cut corner a narrower trapezoid along the first direction, which is not convenient for die-cutting and die-cutting positioning, and is not conducive to die-cutting. If B / A is greater than 0.5, the upper base of the trapezoid formed by the cut corner is too large relative to the height of the trapezoid, making the overall shape of the cut corner a relatively wider trapezoid along the first direction. When the range of the vertical distance B from the first intersection point 105 to the second side edge 102 is determined, it is necessary to set the value of the vertical distance A from the first cut edge 103 to the first side edge 101 to a very small value. Then the length to be cut off on the second side edge 102 is too short, the processing difficulty is large, it is not conducive to die-cutting, and the cut corner effect is not obvious. There is still a risk that the corner of the electrode body will puncture the diaphragm. Therefore, by defining the relationship between the vertical distance B from the first intersection point 105 to the second side 102 and the vertical distance A from the first cutting edge 103 to the first side 101 as 0.1≤B / A≤0.5, it is not only convenient for die-cutting and die-cutting positioning, but also reduces the risk of the corners of the electrode body 1 puncturing the separator, thereby improving the safety of the battery.
[0047] It should be noted that, based on limiting the vertical distance A from the first cut edge 103 to the first side edge 101 to be within the range of 3mm to 5mm, and the vertical distance B from the first intersection point 105 to the second side edge 102 to be within the range of 0.5mm to 1.5mm, the ratio B / A between the vertical distance B from the first intersection point 105 to the second side edge 102 and the vertical distance A from the first cut edge 103 to the first side edge 101 is further limited to be within the range of 0.1 to 0.5, thereby achieving a further specific limitation on the chamfer on the electrode body 1 and ensuring the rationality of the chamfer size.
[0048] In one embodiment, the first tangent 103 and the second tangent 104 are constructed with a rounded transition, and the radius of the circle containing the rounded corner is R, wherein 1mm≤R≤2mm. By setting the first cutting edge 103 and the second cutting edge 104 to a rounded corner for a smooth transition, compared with the structure where the first cutting edge 103 and the second cutting edge 104 are directly connected to form a sharp corner, burrs at the sharp corner can be reduced, thereby avoiding burr damage to the diaphragm. It can also reduce the phenomenon of stress concentration at the corner, reducing the risk of breakage of the electrode body 1 at the connection between the first cutting edge 103 and the second cutting edge 104. If the radius R of the circle where the rounded corner is located is less than 1 mm, the rounded corner is too small and close to a sharp corner, and burrs are still easy to be generated at this point. If R is greater than 2 mm, the rounded corner is too large, making the actual size remaining on the first cutting edge 103 after deducting the area occupied by the rounded corner too small, which is not conducive to die-cutting positioning. Therefore, by setting the radius R of the circle where the rounded corner is located to be between 1 mm and 2 mm, burrs can be reduced and safety can be improved. It can also avoid the phenomenon that the remaining size of the first cutting edge 103 along the first direction is too small, thereby ensuring the smooth progress of die-cutting positioning and ensuring the processing efficiency of the corner cutting process.
[0049] It should be noted that since the first cut edge 103 and the second cut edge 104 are connected by a rounded corner, the first intersection point 105 formed by the intersection of the first cut edge 103 and the second cut edge 104 refers to the intersection point formed by the extension line of the first cut edge 103 and the extension line of the second cut edge 104. It can be understood that, as an alternative implementation, the first cut edge 103 and the second cut edge 104 may not have a rounded corner transition; instead, the first cut edge 103 and the second cut edge 104 may intersect directly to form the first intersection point 105.
[0050] In one embodiment, the second tangent 104 and the first side 101 are connected by a rounded transition, and the radius of the circle containing the rounded corner is R, wherein 1mm≤R≤2mm. By setting a smooth transition between the second cut edge 104 and the first side edge 101 through a rounded corner, burrs at the connection between the second cut edge 104 and the first side edge 101 can be reduced, thereby avoiding damage to the diaphragm by burrs. It can also reduce stress concentration and reduce the risk of the electrode body 1 breaking at the connection between the second cut edge 104 and the first side edge 101. If the radius R of the circle containing the rounded corner is less than 1 mm, the rounded corner is too small and close to a sharp corner, and burrs are still likely to be generated at the connection between the second cut edge 104 and the first side edge 101. If R is greater than 2 mm, the rounded corner is too large, resulting in too much material being cut off from the electrode body 1, which wastes material. Therefore, by setting the radius R of the circle containing the rounded corner to a value between 1 mm and 2 mm, burrs at the connection between the second cut edge 104 and the first side edge 101 can be reduced, improving safety, and material waste can be avoided.
[0051] It should be noted that since the second cut edge 104 and the first side edge 101 are connected by a rounded corner, the second intersection point 106 formed by the intersection of the second cut edge 104 and the first side edge 101 refers to the intersection point formed by the extension line of the second cut edge 104 and the extension line of the first side edge 101. It can be understood that, as an alternative implementation, the second cut edge 104 and the first side edge 101 may not have a rounded corner transition; instead, the second cut edge 104 and the first side edge 101 may intersect directly to form the second intersection point 106.
[0052] In one embodiment, the tab 2 is connected to a first side 101. Along the extending direction of the first side 101, the distance between the second intersection point 106 and the tab 2 is E, where 5mm ≤ E ≤ 30mm. The tab 2 is connected to a first side 101, which has a chamfer at each end along a first direction. Each chamfer forms a second intersection point 106. The distance between the second intersection point 106 and the tab 2 refers to the distance between the second intersection point 106 and the side of the tab 2 closest to that second intersection point along the extending direction of the first side 101. The extending direction of the first side 101 refers to... Figure 1 The "first direction" indicated by the middle arrow. If E is less than 5mm, the distance between the tab 2 and the second intersection point 106 is too close, meaning the tab 2 is too close to the chamfer on the electrode body 1. This can easily damage the tab 2 during the chamfering process, increasing processing difficulty. If E is greater than 30mm, the distance between the second intersection point 106 and the tab 2 is too far, making the tab too close to the other chamfer on the first side 101 connected to the tab 2. This also leads to the problem of accidentally damaging the tab 2 during the chamfering process. Therefore, by setting the distance E between the second intersection point 106 and the tab 2 to a value within the range of 5mm to 30mm, it is possible to ensure that the distance from the tab 2 to both chamfers at the two ends of the first side 101 is reasonable, thereby avoiding accidental damage to the tab 2 during the chamfering process, reducing processing difficulty, and improving processing efficiency.
[0053] In one embodiment, the first side 101 and the second side 102 are perpendicular to each other, the vertical distance between the two first sides 101 is L, and the vertical distance between the two second sides 102 is W, wherein 0.1≤A / L≤0.5 and 0.1≤D / W≤0.3. It should be noted that the vertical distance between the two first side edges 101 is the total dimension of the electrode body 1 along the second direction, and also the total length of the second side edge 102 of the electrode body 1 when the corner is not processed; the vertical distance between the two second side edges 102 is the total dimension of the electrode body 1 along the first direction, and also the total length of the first side edge 101 of the electrode body 1 when the corner is not processed. If A / L is less than 0.1, the proportion of the maximum dimension of the corner along the second direction on the second side edge 102 is too small, the corner is not obvious, and there is still a risk of the sharp corner piercing the diaphragm; if A / L is greater than 0.5, the proportion of the maximum dimension of the corner along the second direction on the second side edge 102 is too large, wasting material; similarly, if D / W is less than 0.1, the proportion of the maximum dimension of the corner along the first direction on the first side edge 101 is too small, the corner is not obvious, and there is still a risk of the sharp corner piercing the diaphragm; if D / W is greater than 0.3, the proportion of the maximum dimension of the corner along the second direction on the second side edge 102 is too large, wasting material. Therefore, by setting the ratio A / L between the vertical distance A from the first cut edge 103 to the first side edge 101 and the vertical distance L between the two first side edges 101 to be in the range of 0.1 to 0.5, and setting the ratio D / W between the vertical distance D from the second intersection point 106 to the second side edge 102 and the vertical distance W between the two second side edges 102 to be in the range of 0.1 to 0.3, it is possible to ensure that the corner cutting effect is obvious, avoid the sharp corners at the edges of the electrode body 1 from piercing the separator, thereby improving the safety of the battery, and also avoid excessive waste of materials.
[0054] In one embodiment, the vertical distance L between the two first sides 101 is in the range of 10mm ≤ L ≤ 600mm; the vertical distance W between the two second sides 102 is in the range of 5mm ≤ W ≤ 200mm. If L is less than 10mm or W is less than 5mm, the electrode body 1 is too small and cannot provide enough active material, which is not conducive to improving the energy density of the battery. If L is greater than 600mm or W is greater than 200mm, the electrode body 1 is too large, resulting in uneven current distribution on the electrode body 1 and low utilization of active material on the electrode body 1, which is not conducive to improving the charge and discharge performance of the battery. Therefore, by setting the vertical distance L between the two first sides 101 to be in the range of 10mm to 600mm and the vertical distance W between the two second sides 102 to be in the range of 5mm to 200mm, it is beneficial to improve both the energy density and the charge and discharge performance of the battery.
[0055] The electrode structure in this embodiment optimizes the process parameters for the chamfering around the electrode, thereby improving battery safety performance and production yield.
[0056] It should be noted that the electrode body 1 includes a foil 11 and an active material layer 12. The active material layer 12 is coated on the surface of the foil 11, and the electrode tab 2 extends from a portion of the foil 11. Further integration... Figure 6 As shown, Figure 6 This is a magnified schematic diagram of a portion of the electrode body 1 near its edge. Figure 6 The "thickness direction" indicated by the middle arrow is perpendicular to... Figure 1 The plane formed by the first and second directions in the middle, for the burrs 111 at the edge of the electrode body 1, requires that the size M1 of the burrs 111 extending horizontally out of the area covered by the active material layer 12 satisfies: M1≤15um, the burrs 111 not exceeding the surface of the active material layer 12 in the thickness direction, and the shortest distance H1 between the burrs 111 and the surface of the active material layer 12 satisfies: H1≥10um. Further combining... Figure 7 As shown, Figure 7 This is a magnified schematic diagram of a portion of the edge of the tab 2 away from the electrode body 1. Figure 7 The "thickness direction" indicated by the middle arrow is... Figure 6 The "thickness direction" is the same. For the burr 111 on the edge of the tab 2, the dimension M2 of the burr 111 extending horizontally out of the edge of the tab 2 must satisfy: M2≤15μm, and the shortest distance H2 between the burr 111 and the surface of the tab 2 along the thickness direction must satisfy: H2≤15μm. Here, "horizontal direction" refers to... Figures 6 to 7 The "horizontal direction" indicated by the middle arrow is the same as the horizontal direction. Figure 1 The planes containing the "first direction" and "second direction" indicated by the middle arrow are parallel.
[0057] According to an embodiment of the present invention, another aspect provides a battery comprising the above-described electrode structure.
[0058] In one embodiment, such as Figure 8 As shown, the battery is a pouch battery, which includes an electrode assembly. The electrode assembly includes the aforementioned electrode structure and a separator. Specifically, the electrode structure includes a positive electrode and a negative electrode, which are stacked sequentially in the order of negative electrode, separator, positive electrode, negative electrode, etc. to form the electrode assembly. The pouch battery also includes: an encapsulation film 3, which covers the outside of the electrode assembly to seal and encapsulate the electrode assembly; and an adapter piece, one end of which is welded to the electrode tab of the electrode assembly and the other end extends out of the encapsulation film 3.
[0059] Specifically, the encapsulation film 3 includes an upper encapsulation film and a lower encapsulation film. One of the upper and lower encapsulation films has a perforation corresponding to the electrode group. The electrode group is located in the perforation. The four sides of the upper and lower encapsulation films are heat-sealed to form a seal 301, thereby forming a sealed space that encloses the electrode group. The electrode group includes a positive electrode tab and a negative electrode tab. The adapter includes a positive electrode adapter 4 and a negative electrode adapter 5. The positive electrode adapter 4 is welded to the positive electrode tab, and the negative electrode adapter 5 is welded to the negative electrode tab, thereby realizing the separate lead-out of the positive and negative electrodes of the battery.
[0060] Preferably, the encapsulation film 3 is an aluminum-plastic film, which has advantages such as good protective performance, high safety performance, high energy density, and good stability.
[0061] In one embodiment, a sealant 6 is provided between the adapter piece and the encapsulation film 3, and the section on the seal 301 corresponding to the adapter piece is pressed onto the sealant 6 to improve the sealing between the encapsulation film 3 and the adapter piece and ensure the safety of the battery.
[0062] In other embodiments, the battery may also be a prismatic battery.
[0063] 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. An electrode structure, characterized in that, include: The electrode body and the electrode tab are connected to the electrode body. The electrode body has two first sides and two second sides arranged opposite to each other. The four corners of the electrode body are all constructed as chamfers. The electrode body has a first chopped edge and a second chopped edge formed at the chamfer position. The first chopped edge is parallel to the first side, and the second chopped edge is inclined relative to the second side. The first end of the second chopped edge is connected to the end of the first chopped edge away from the second side, and the intersection between the first chopped edge and the second chopped edge is the first intersection point. The second end of the second chopped edge is connected to the first side, and the intersection between the second chopped edge and the first side is the second intersection point. The vertical distance from the first intersection point to the second side is B, and the vertical distance from the second intersection point to the second side is D, where 0.15≤B / D≤0.3 and 0.5mm≤B≤1.5mm.
2. The electrode structure according to claim 1, characterized in that, The angle between the second cut edge and the second side edge is θ, where 30°≤θ≤45°.
3. The electrode structure according to claim 1, characterized in that, The vertical distance D from the second intersection point to the second side is in the range of 2mm ≤ D ≤ 6.5mm.
4. The electrode structure according to claim 3, characterized in that, The vertical distance from the first cut edge to the first side edge is A, where 3mm≤A≤5mm.
5. The electrode structure according to claim 4, characterized in that, The perpendicular distance B from the first intersection point to the second side and the perpendicular distance A from the first tangent to the first side satisfy the following relationship: 0.1≤B / A≤0.
5.
6. The electrode structure according to claim 1, characterized in that, The first cut edge and the second cut edge are connected by a rounded corner transition, and / or the second cut edge and the first side edge are connected by a rounded corner transition, wherein the radius of the circle containing the rounded corner is R, where 1mm≤R≤2mm.
7. The electrode structure according to claim 1, characterized in that, The electrode tab is connected to the first side. Along the extension direction of the first side, the distance between the second intersection point and the electrode tab is E, where 5mm≤E≤30mm.
8. The electrode structure according to any one of claims 1 to 7, characterized in that, The first side is perpendicular to the second side, the vertical distance between the two first sides is L, and the vertical distance between the two second sides is W, where 0.1≤A / L≤0.5 and 0.1≤D / W≤0.
3.
9. The electrode structure according to claim 1, characterized in that, The vertical distance L between the two first sides is in the range of 10mm≤L≤600mm; The vertical distance W between the two second sides is in the range of 5mm ≤ W ≤ 200mm.
10. A battery, characterized in that, include: The electrode structure according to any one of claims 1 to 9.