Current collector tabs for electrodes
Patent Information
- Authority / Receiving Office
- ES · ES
- Patent Type
- Patents
- Current Assignee / Owner
- VERKOR SA
- Filing Date
- 2025-05-19
- Publication Date
- 2026-07-15
AI Technical Summary
Rectangular current collection tabs in electrochemical cell electrodes are prone to damage due to right-angled corners, leading to snagging and jamming during transport, which disrupts production and reduces efficiency.
The current collection tabs are designed with a distal portion featuring a fold or pre-cut line with weakenings such as slits or scratches, allowing the tab to deform around an obstacle without forming a right angle, reducing the risk of damage.
The design minimizes tab damage during transport, enhancing production efficiency by preventing creasing and snagging, thus maintaining continuous production.
Smart Images
Figure 00000007_0000 
Figure 00000007_0001 
Figure 00000008_0000
Abstract
Description
[0001] The present invention relates to the electrodes of electrochemical cells of prismatic or bag geometry and more particularly to the current collection tabs of such electrodes.
[0002] These electrodes are made from a metal foil (typically copper or aluminum) initially wound onto itself into a coil. Once unwound, the metal foil is partially coated with an active material. A portion of the metal foil uncoated with active material extends along one longitudinal edge of the foil. During a notching operation, current-collecting tabs are formed along the metal foil by cutting directly into the uncoated portion. These current-collecting tabs, devoid of active material, protrude from one longitudinal edge of the active portion.
[0003] Each current-collecting tab is rectangular in shape, comprising a proximal portion bonded to the metal foil and designed for electrical connection to a current collector, and a distal portion designed to receive marking (an inscription, code, or other temporary identification mark during electrode manufacturing). The distal portion protrudes from the proximal portion. Once the proximal portion is soldered to a current collector, the distal portion is removed during a deburring operation.
[0004] One disadvantage of these rectangular current collection strips is that they have right-angled corners on their free edges opposite their attachment bases to the metal sheet.
[0005] Indeed, given its length, a current-collecting tab extending horizontally from the electrode moving along a conveyor is likely, under its own weight, to bend downwards and potentially come into contact with a conveyor component or, more generally, with an obstacle. In the event of such contact, the right angle at the free edge of the current-collecting tab most often causes it to crease.
[0006] When encountering an obstacle along its path, a right angle on the free edge of the current-collecting tab tends to act as an anchor point, causing damage to the tab. In other words, the distinctive perpendicular shape of the right angles on the free edge of current-collecting tabs makes them susceptible to snagging or jamming when they encounter an obstacle during electrode transport.
[0007] More generally, rectangular current-collecting tabs with a proximal portion bonded to the metal foil and a distal portion protruding from it are susceptible to potential damage during electrode transport. When such damage occurs, the electrodes are discarded and the production lines are shut down, slowing the production rate of electrochemical cells and impacting the overall plant output.
[0008] WO 2023 / 123274 A1 describes an electrode composed of a metallic foil with an active portion coated with an active material and a bare metallic portion along a longitudinal edge. This bare portion has a current-collecting tab that protrudes from the active portion. The tab comprises a proximal part bonded to the foil and a projecting distal part. This distal part has two lateral edges: the second edge approaches the first as it moves away from the proximal portion, meaning that the tab narrows towards its tip.
[0009] One object of the present invention is to remedy the aforementioned drawbacks.
[0010] Another object of the present invention is to avoid any risk of damage to the current collection tabs during the transport of electrodes suitable for the manufacture of electrochemical cells of prismatic geometry or in sachets.
[0011] Another object of the present invention is to reduce the defects that may occur during the conveying of the electrode sheet on a conveyor and, consequently, to improve the production rate of electric battery cells.
[0012] To this end, it is proposed, firstly, an electrode comprising a metallic foil with an active portion coated with an active material; a metallic portion devoid of active material extending over a longitudinal edge of the metallic foil, this metallic portion comprising a current-collecting tab projecting from a longitudinal edge of the active portion; said current-collecting tab comprising a proximal portion bonded to the metallic foil; a distal portion projecting from the proximal portion; a fold line or a pre-cut line separating the proximal portion from the distal portion, said fold or pre-cut line comprising weakenings such as slits or scratches; electrode in which the distal portion comprises a first lateral edge; a second lateral edge opposite the first lateral edge, this second lateral edge approaching the first lateral edge as one moves away from the proximal portion.
[0013] Various additional features can be provided, either alone or in combination: the distal portion is triangular, semi-circular, semi-elliptical, trapezoidal, rectangular with one corner rounded, rectangular with two corners rounded on the same side, rectangular with one corner trimmed, rectangular with two corners trimmed on the same side, rectangular with one corner trimmed and one corner rounded on the same side; the width of the current-collecting tab in the direction of the longitudinal edge of the metal foil is greater than half the length of the current-collecting tab, two-thirds the length of the current-collecting tab, or three-quarters the length of the current-collecting tab; the distal portion is suitable for receiving a marking; the fold line or the pre-cut line is connected to the first lateral edge and / or the second lateral edge; the distal portion is suitable for receiving a marking;The folding or pre-cutting line is designed to facilitate folding of the distal portion relative to the proximal portion.
[0014] Secondly, a method for manufacturing an electrode comprising a metallic foil is proposed. an active portion coated with an active material; a metallic portion devoid of active material extending over a longitudinal edge of the metallic foil, this method comprising a cutting step in the metallic portion of a current-collecting tab extending projecting from a longitudinal edge of the active portion, this current-collecting tab comprising a proximal portion connected to the metallic foil; a distal portion, the distal portion projecting from the proximal portion; method in which, the cutting step comprises a first cutting of a first lateral edge of the distal portion;a second cut of a second lateral edge of the distal portion opposite the first lateral edge, this second lateral edge approaching the first lateral edge, depending on whether one moves away from the proximal portion, a step of creating a fold line or a pre-cut line between the proximal and distal portions of the current-collecting tab, said fold or pre-cut line including weakenings such as slits or scratches. ;
[0015] Various additional features can be provided, either alone or in combination: The process described above further includes a step of conveying the metal sheet, the second lateral edge being downstream, with respect to the direction of conveying the metal sheet, of the first lateral edge; the distal portion is triangular, semi-circular, semi-elliptical, trapezoidal, rectangular rounded at one corner, rectangular rounded at two corners on the same side, rectangular with one corner trimmed, rectangular with two corners trimmed on the same side, rectangular with one corner trimmed and one corner rounded on the same side; the process described above further includes a step of creating a bend line or a pre-cut line in the distal portion; the bend line or the pre-cut line is connected to the first lateral edge and / or the second lateral edge.
[0016] Other features and advantages of the invention will become clearer and more concrete upon reading the following description of embodiments, which is made with reference to the accompanying drawings in which: the figure [ Fig.1 ] schematically illustrates a metallic sheet in various embodiments; the figure [ Fig.2 ] schematically illustrates a first embodiment of the metallic sheet; the figure [ Fig.3 ] schematically illustrates a second embodiment of the metallic sheet; the figure [ Fig.4 ] schematically illustrates a third embodiment of the metallic foil; the figure [ Fig.5 ] schematically illustrates a fourth embodiment of the metallic foil; the figure [ Fig.6 ] schematically illustrates the steps of a manufacturing process for an electrode comprising a metallic foil according to various embodiments.
[0017] On the [ Fig.1 [A sheet of paper is shown] 1 metallic material moving along a conveyor belt 2. This leaflet 1 metallic includes a portion 3 active coated with an active material and a portion 4 metallic, devoid of active material, extending along a longitudinal edge of the leaflet 1 metallic.
[0018] A device 5 The cutting (or notching) tool is configured to cut, in the portion 4 metallic strip devoid of active material 6 current collection extending projecting from an edge 31 longitudinal portion 3 active (or, equivalently, of the sheet) 1 metallic).
[0019] As illustrated by the [ Fig.1 ], the tongue 6 current collection includes a portion 61 proximal linked to the leaflet 1metallic. The current collection tab 6 is suitable for electrical connection to a current collector (not shown in the drawings). The current collection tab 6 comprises a portion 62 distal. The distal portion 62 is suitable for marking. The portion 62 distal protrudes from the portion 61 proximal.
[0020] The portion 62 distal includes a first edge 63 lateral and a second edge 64 lateral in relation to the first edge 63 lateral, this second edge 64 lateral approaching, moving away from the portion 61 proximal, of the first edge 63 lateral.
[0021] Tab 6 includes a fold line or a pre-cut line. The fold or pre-cut line L is positioned between the portion 61 proximal portion 62distal. This L-line may include weakenings such as slits or scratches facilitating the folding of the portion 62 distal relative to the proximal portion 61.
[0022] Advantageously, the particular shape of the second edge 64 Lateral avoidance prevents the formation of a right angle that could act as a snagging or anchoring point, causing damage to the tongue. 6 current collection occurs when it encounters an obstacle while moving along the conveyor. 2. Consequently, less damage is caused to the tongue. 6 current collection during the conveying of electrodes suitable for the manufacture of electrochemical cells of prismatic geometry or in sachets.
[0023] In addition, the L-shaped folding or pre-cut line between the portion 61 proximal portion 62The distal part advantageously allows for the absorption of the effect of a possible collision between the tongue 6 current collection tab 6 and an external obstacle. Thus, in the event of a collision between the current collection tab 6 and an external obstacle, the distal portion 62 will be able to rotate around the line L, which reduces the risk of damage to said current collection tab 6.
[0024] In some embodiments, the portion 62 distal is triangular in shape as illustrated by the [ Fig.2 ], semi-circular, semi-elliptical, trapezoidal as illustrated by the [ Fig.3 ], rectangular rounded at one corner, rectangular rounded at two corners on the same side as illustrated by the [ Fig.4 ], rectangular with one corner trimmed, rectangular with two corners trimmed on the same side, or rectangular with one corner trimmed and one corner rounded on the same side as illustrated by the [ Fig.5 Such forms are, advantageously, easy to implement by the device 5 cutting.
[0025] In another embodiment, the width of the tongue 6 current collection in the direction of the edge 31 longitudinal portion 3 active is greater than half the length (in a direction perpendicular to the edge) 31 longitudinal portion 3 active) of the tongue 6 current collection, at two-thirds of the tongue's length 6 current collection, or three-quarters of the length of the tongue 6 current collection.
[0026] Such relationships between the dimensions of the tongue 6 current collection systems advantageously prevent free flexing of the tongue. 6 current collection under the effect of its own weight. A collision between the tongue6 current collection and a conveyor element 2 can, therefore, be avoided.
[0027] In one embodiment, the folding line or pre-cutting line is connected to the first edge 63 lateral and / or second edge 64 Lateral. In other words, the fold or cut line includes a portion starting or ending on the first edge 63 lateral and / or on the second edge 64 Lateral. Depending on its direction, such a folding or pre-cutting line allows for a preferred direction of tongue deformation. 6 current collection occurs when it encounters an obstacle. A rustling of the tab 6 Current collection can, therefore, be avoided.
[0028] Referring to the [ Fig.6 ], a manufacturing process for an electrode incorporating the foil 1 metal includes a cutting step 10, in the portion4 metallic, with a tongue 6 current collection extending projecting from an edge 31 longitudinal portion 3 active. This cutting step includes an initial cut of the first edge. 63 lateral portion 62 distal and a second cut of the second edge 64 lateral portion 62 distal opposite the first edge 63 lateral. Moving away from the portion 61 proximal, the second edge 64 lateral approaches the first edge 63 lateral so as to avoid the formation of a right angle which could act as a snagging or anchoring point causing damage to the current collection tongue when it encounters an obstacle during its movement.
[0029] In addition, the manufacturing process includes a step 12 of creating an L-shaped folding or pre-cutting line between the portion 61proximal portion 6 2 distal. The fold line or pre-cut line includes weakenings such as slits or scratches.
[0030] During the transport (step 11 on the [ Fig.6 ]) of the sheet 1 metallic, the second edge 64 Lateral is downstream, relative to the direction 7 of the sheet conveyance 1 metallic, from the first edge 63 Lateral. Such an arrangement of the edges 63, 64 lateral portion 62 distal in relation to the direction 7 Conveyance involves the second edge 64 lateral which helps to reduce the risk of the tongue getting creased 6 current collection in the event of contact with a conveyor component 2 of the sheet conveyance 1 metallic.
[0031] The folding line or pre-cutting line is connected to the first edge (63)lateral and / or second edge (64) lateral.
Claims
1. Electrode comprising a metal sheet (1), said metal sheet comprising - an active portion (3) coated with an active material; - a metal portion (4) without active material, extending along a longitudinal edge of the metal sheet, this metal portion comprising a current-collecting tab (6) projecting from a longitudinal edge of the active portion (3); said current-collecting tab (6) comprising - a proximal portion (61) connected to the metal sheet (1); - a distal portion (62) projecting from the proximal portion (61); - a folding line or a pre-cut line separating the proximal portion (61) from the distal portion (62), said folding or pre-cut line (L) comprising weakenings such as slits or scores; wherein the distal portion (62) comprises - a first lateral edge (63); - a second lateral edge (64) opposite the first lateral edge, this second lateral edge (64) coming closer to the first lateral edge (63) as the distance from the proximal portion (61) increases.
2. Electrode according to the preceding claim, characterized in that the distal portion (62) is triangular, semicircular, semi-elliptical, trapezoidal, rectangular having one rounded corner, rectangular having two rounded corners on the same side, rectangular having one trimmed corner, rectangular having two trimmed corners on the same side, rectangular having one trimmed corner and one rounded corner on the same side.
3. Electrode according to claim 1 or claim 2, characterized in that the width of the current-collecting tab (6) in the direction of the longitudinal edge of the metal sheet is greater than half the length of the current-collecting tab (6), greater than two-thirds the length of the current-collecting tab (6), or greater than three-quarters the length of the current-collecting tab (6).
4. Electrode according to any of the preceding claims, characterized in that the folding line or the pre-cut line is connected to the first lateral edge and / or the second lateral edge.
5. Electrode according to any of the preceding claims, wherein the distal portion (62) is capable of receiving a marking.
6. Electrode according to any of the preceding claims, wherein the folding or pre-cut line is capable of facilitating the folding of the distal portion (62) with respect to the proximal portion (61).
7. Method for manufacturing an electrode comprising a metal sheet (1), said metal sheet comprising - an active portion (3) coated with an active material; - a metal portion (4) without active material, extending along a longitudinal edge of the metal sheet, this method comprising a cutting step (10) of cutting, into the metal portion (4), a current-collecting tab (6) projecting from a longitudinal edge (31) of the active portion (3), said current-collecting tab (6) comprising - a proximal portion (61) connected to the metal sheet (1); - a distal portion (62), the distal portion (62) projecting from the proximal portion (61); wherein the cutting step comprises - a first cut of a first lateral edge (63) of the distal portion; - a second cut of a second lateral edge (64) of the distal portion opposite the first lateral edge (63), this second lateral edge (64) coming closer to the first lateral edge (63) as the distance from the proximal portion (61) increases, - a creating step (12) of creating a folding line or a pre-cut line between the proximal portion (61) and the distal portion (62) of the current-collecting tab, said folding or pre-cut line (L) comprising weakenings such as slits or scores.
8. Method according to the preceding claim, characterized in that it further comprises a conveying step (11) of conveying the metal sheet (1), the second lateral edge (64) being downstream from the first lateral edge (63) with respect to the conveying direction (7) of the metal foil (1).
9. Method according to claim 7 or claim 8, characterized in that the distal portion (62) is triangular, semicircular, semi-elliptical, trapezoidal, rectangular having one rounded corner, rectangular having two rounded corners on the same side, rectangular having one trimmed corner, rectangular having two trimmed corners on the same side, rectangular having one trimmed corner and one rounded corner on the same side.
10. Method according to any of claims 7 to 9, characterized in that the folding line or the pre-cut line is connected to the first lateral edge (63) and / or the second lateral edge (64).