SYSTEM AND METHOD FOR CUTTING TABS IN AN ACCUMULATOR CELL FILM FOR A STACKED ACCUMULATOR CELL

Abstract

A system for forming tabs in an accumulator cell film comprises a web roller with a surface and a guide element carrier part that is slidably connected to the web roller. The guide element carrier part includes a guide element bearing surface. A plurality of guide elements is supported on the guide element carrier part. Each of the plurality of guide elements is assigned to a different tab dimension. The plurality of guide elements is selectively displaceable relative to the surface of the web roller. A tab cutting mechanism is directed at one of the plurality of guide elements. A control system is operatively connected to the guide element carrier part.The control system is able to selectively move selected guide elements from the multitude into alignment with the tab cutting mechanism in order to selectively control the dimensional properties of tabs formed in a moving sheet of the accumulator cell film.

Description

INTRODUCTION

[0001] The subject matter of the disclosure relates to the art of battery manufacturing and, more particularly, to a system and method for cutting tabs into a battery cell foil for a stacked battery cell.

[0002] The battery cells are made of stacked foils separated by an insulator. A first section of the stacked foils is connected to form the battery cell's cathode, and a second section of the stacked foils is connected to form the battery cell's anode. Typically, a laser cuts notches into the foils. The notches form evenly lengthened tabs that become a joint. A welding plate is slid over the tabs to fold them before welding.

[0003] The uniform length of the tabs creates overlapping surfaces during folding. During the welding process, the overlapping surfaces do not form a stable connection. Changing the length of the tabs is not feasible. The tabs are cut while the film is moving. Therefore, changing the tab length would require stopping the film, changing the laser settings, and restarting the film. The time and effort required to change tab settings increases production costs and complexity. Accordingly, it is desirable to provide a system that allows adjustable tab lengths without interrupting the production flow. SUMMARY

[0004] A system for forming tabs in a battery cell foil, according to one non-limiting example, comprises a web roll having a surface and a guide element support member slidably connected to the web roll. The guide element support member includes a guide element support surface substantially coplanar with the surface of the web roll. A plurality of guide elements are supported on the guide element support member. Each of the plurality of guide elements is associated with a different tab dimension. The plurality of guide elements is selectively slidable relative to the surface of the web roll. A tab cutting mechanism is directed toward one of the plurality of guide elements. A control system is operatively connected to the guide element support member.The control system is capable of selectively moving selected ones of the plurality of guide elements into alignment with the tab cutting mechanism to selectively control the dimensional characteristics of tabs formed in a moving sheet of battery cell foil.

[0005] In addition to one or more of the features described herein, the tab cutting mechanism includes a laser.

[0006] In addition to one or more of the features described herein, the web roll comprises a cylinder having a first end and a second end defining a web roll axis, wherein the surface is defined between the first end and the second end.

[0007] In addition to one or more of the features described herein, the guide element support member is disposed at the first end and is rotatable about the web roller axis.

[0008] In addition to one or more of the features described herein, the plurality of guide elements comprises a first guide element having a first dimension defined along the web roll axis, a second guide element having a second dimension defined along the web roll axis and greater than the first dimension, and a third guide element having a third dimension defined along the web roll axis and greater than the second dimension.

[0009] In addition to one or more of the features described herein, each of the plurality of guide elements is circumferentially spaced from others of the plurality of guide elements along the guide element support portion.

[0010] In addition to one or more of the features described herein, a quantity of accumulator film is fed over the web roller, wherein the tab cutting mechanism forms a plurality of tabs in the accumulator film.

[0011] A method for forming tabs in a battery cell foil according to a non-limiting example includes passing the battery cell foil over a web roller having a web roller axis, supporting a portion of the battery cell foil on a guide element support member having a plurality of guide elements, directing a tab cutting mechanism to a first one of the plurality of guide elements, cutting a first tab into the portion of the battery cell foil, the first tab having a first dimension corresponding to the first one of the plurality of guide elements, translating the guide element support member while passing the battery cell foil over the web roller to align a second one of the plurality of guide elements with the tab cutting mechanism, and cutting a second tab into the portion of the battery cell foil, the second tab having a second dimension.which differs from the first dimension and corresponds to the second of the plurality of guide elements.,

[0012] In addition to one or more of the features described herein, the tab cutting mechanism includes directing a laser toward the first of the plurality of guide members.

[0013] In addition to one or more of the features described herein, cutting the tab includes guiding the laser through the battery cell foil into the first of the plurality of guide elements.

[0014] In addition to one or more of the features described herein, guiding the laser through the battery cell foil includes guiding the laser to follow a pattern embodied by the first of the plurality of guiding elements.

[0015] In addition to one or more of the features described herein, the method further comprises further translating the guide member support member while advancing the battery cell foil over the web roller to align a third of the plurality of guide members with the tab cutting mechanism.

[0016] In addition to one or more of the features described herein, a third tab is cut into the portion of the battery cell foil, the third tab having a third dimension different from the first dimension and the second dimension and corresponding to the third of the plurality of guide elements.

[0017] In addition to one or more of the features described herein, translating the guide member support member includes rotating the guide member support member relative to the web roller.

[0018] In addition to one or more of the features described herein, cutting the first tab having the first dimension includes forming the first tab having a first length defined along the web roll axis of the web roll.

[0019] In addition to one or more of the features described herein, cutting the second tab having a second dimension includes forming the second tab having a second length defined along the web roll axis of the web roll.

[0020] In addition to one or more of the features described herein, forming the second tab having the second length includes forming the second tab such that it is shorter than the first tab.

[0021] In addition to one or more of the features described herein, a storage battery cell is formed by the described method.

[0022] In addition to one or more of the features described herein, directing the tab cutting mechanism toward the first of the plurality of guide members includes activating a laser.

[0023] In addition to one or more of the features described herein, activating the laser includes guiding the laser through the battery cell foil and tracing a pattern defined by the first of the plurality of guide elements to form the first tab.

[0024] The foregoing features and advantages, as well as other features and advantages of the disclosure, will be readily apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further features, advantages and details are listed only as examples in the following detailed description, which refers to the drawings in which: Fig. 1 shows a web roller and a displaceable guide element part of a flap cutting system according to a non-limiting example in a schematic view, Fig. 2 a flap cutting mechanism directed towards a film which is guided over the web roller and the movable guide element of Fig. 1, according to a non-limiting example in a schematic view, Fig. 3 shows a foil whose tab dimensions are changed on-the-fly by the tab cutting system, according to a non-limited example, in a plan view, and Fig. 4 shows two accumulator cells formed with the tab cutting system, according to a non-limiting example, in a plan view. DETAILED DESCRIPTION

[0026] The following description is merely exemplary and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the drawings, corresponding reference characters designate like or corresponding parts and features. As used herein, the term module refers to a processing circuit, which may include an application-specific integrated circuit (ASIC), an electronic circuit, a processor (common, dedicated, or group), and memory executing one or more software or firmware programs, a combinational logic circuit, and / or other suitable components that provide the described functionality.

[0027] A system for forming tabs in a battery cell foil according to a non-limiting example is described in Fig. 1 and 2 at 10. The tab forming system 10 includes a web roll 12 shown in the form of a cylinder 14. It should be noted that the web roll 12 can take a variety of shapes. The web roll 12 includes a first end 20, a second end 22, and an outer surface 24 extending between the first end 20 and the second end 22. The web roll 12 includes a web roll axis "A" extending between the first end 20 and the second end 22.

[0028] In one non-limiting example, a guide member support member 34 having a guide member support surface 36 is slidably mounted to the first end 20 of the web roll 12. In one non-limiting example, the guide member support member 34 is selectively rotatable about the web roll axis "A" relative to the cylinder 14, as described in more detail herein. A plurality of guide members 42 are disposed on the guide member support surface 36. In the non-limiting example shown, the plurality of guide members 42 includes a first guide member 44, a second guide member 46, and a third guide member 48 circumferentially spaced apart from one another on the guide member support surface 36. It will be appreciated that the number of guide members may vary.

[0029] In one non-limiting example, the first guide member 44 includes a first dimension "D1" measured along the web roll axis "A." The second guide member 46 includes a second dimension "D2" measured along the web roll axis "A." The third guide member 48 includes a third dimension "D3" measured along the web roll axis "A." In one non-limiting example, D1 is greater than D2 and D3, and D2 is greater than D3. It should be noted that the order and relative position of the first guide member 44, the second guide member 46, and the third guide member 48 may vary. As described in more detail below, the first guide member 44, the second guide member 46, and the third guide member 48 are each associated with forming a film flap having a selected length.

[0030] In one non-limiting example, a flap cutting mechanism 60 is disposed outside the web roll 12, as shown in Fig. 2. The tab cutting mechanism 60 includes a fixedly mounted laser 64 directed toward the guide support surface 36. As a non-limiting example, the guide support member 34 is selectively positioned so that one of the plurality of guide elements 42 is aligned with the laser 64. As described in more detail herein, the guide support member 34 is selectively rotated about the web roll axis "A" to position the first guide element 44, the second guide element 46, or the third guide element 48 in alignment with the laser 64. As further described in more detail herein, the guide support member 34 can rotate without interrupting the tab cutting operations.

[0031] In a non-limiting example, a control system 70 ( Fig. 1) is operatively connected to the guide support member 34. The control system 70 may be directly wired to the guide support member 34 or connected via one or more wireless communication protocols. The control system 70 includes a central processing unit (CPU) 72, a guide element control module 74, and a memory 76. The control system 70 receives information, which may be in the form of programming, via an input 78 and controls a position of the guide element support member 34 relative to the web roller 12 to form tabs in a continuous sheet of battery cell foil 80, as shown in Fig. 3 shown.

[0032] In one non-limiting example, a continuous sheet of battery cell foil 80 runs over the outer surface 24 of the web roll 12. An outer edge portion 84 of the battery cell foil 80 is guided over the guide member support surface 36 of the guide member support member 34. One of the plurality of guide members 42 is aligned with the laser 64. In one non-limiting example, the third guide member 48 may be centered under the laser 64. The laser 64 may be activated and controlled to trace a pattern defined by the third guide member 48. The laser 64 penetrates through the battery cell foil 80 into the third guide member 48 to form a first tab 86 having a dimension D3. The number of first tabs 86 produced may vary.

[0033] After producing a selected number of first tabs 86, the control system 70 moves the guide member support member 34 to align the second guide member 46 with the laser 64. The second guide member 46 is aligned with the laser 64 without stopping the movement of the battery cell foil 80 over the outer surface 24 of the web roll 12. Thus, without interrupting the workflow, a second plurality of tabs 88 are formed in the outer edge portion 84 of the battery cell foil 80. As a non-limiting example, once the second guide member 46 is in position, the laser 64 can be activated and controlled to trace a pattern defined by the second guide member 46. The laser 64 penetrates through the battery cell foil 80 into the second guide member 46 to form a second tab 88 having a dimension D2. The number of second tabs 88 produced can vary.

[0034] After producing a selected number of second tabs 88, the control system 70 moves the guide member support member 34 to align the first guide member 44 with the laser 64. The first guide member 44 is aligned with the laser 64 without stopping the movement of the battery cell foil 80 over the outer surface 24 of the web roll 12. Thus, without interrupting the workflow, a third plurality of tabs 90 are formed in the outer edge portion 84 of the battery cell foil 80. As a non-limiting example, once the first guide member 44 is in position, the laser 64 can be activated and controlled to trace a pattern defined by the first guide member 44. The laser 64 penetrates through the battery cell foil 80 into the first guide member 44 to form a third tab 90 having a dimension D1. The number of third tabs 90 produced can vary.

[0035] In one non-limiting example, the battery cell foil 80 may be cut into individual sheets to form a battery cell 94, as shown in Fig. 4. The storage battery cell 94 includes a plurality of foil sheets 96 forming cathodes such as those shown at 98 and anodes such as those shown at 100. Each cathode and anode pair is separated by a separator sheet 104. A first portion 106 of the cathodes 98 may include a plurality of tabs having a first length, and a second portion 108 of the cathodes 98 may include tabs having a second length. Similarly, a first portion 110 of the anodes 100 may include a plurality of tabs having a first length, and a second portion 112 of the anodes 100 may include tabs having a second length. By varying the length of the tabs, welds can overlap more easily, resulting in more robust and reliable welds.

[0036] The terms "a", "an" and "another" do not imply a limitation of quantity, but rather indicate the presence of at least one of the recited elements. The term "or" means "and / or" unless the context clearly indicates otherwise. Reference throughout this specification to "an aspect" means that a particular element (e.g., a feature, structure, step, or property) described in connection with the aspect is included in at least one of the aspects described herein and may or may not be present in other aspects. It is understood that the described elements in the various aspects may be combined in any suitable way.

[0037] When an element such as a layer, film, region, or substrate is described as lying "on" another element, it may lie directly on top of the other element, or there may be intervening elements. In contrast, when an element is described as lying "directly on" another element, there are no intervening elements.

[0038] Unless otherwise indicated herein, all examination standards are the most recent standard in effect as of the filing date of this application or, if priority is claimed, as of the filing date of the earliest priority application in which the examination standard appears.

[0039] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0040] While the above disclosure has been described with reference to exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalent elements may be substituted without departing from the scope of the disclosure. Furthermore, many changes may be made to adapt a particular situation or material to the teachings of the disclosure without departing from its essential scope. Therefore, the present disclosure is not intended to be limited to the particular embodiments disclosed, but is intended to include all embodiments falling within its scope.

Claims

[1] A system for forming tabs in a battery cell foil, comprising: a web roller with a surface, a guide element support part which is slidably connected to the web roller, the guide element support part comprising a guide element support surface which lies substantially in a plane with the surface of the web roller, a plurality of guide elements carried on the guide element support member, each of the plurality of guide elements being associated with a different tab dimension, the plurality of guide elements being selectively displaceable relative to the surface of the web roller, a tab cutting mechanism directed toward one of the plurality of guide elements, and a control system operatively connected to the guide member support member, the control system capable of selectively translating selected ones of the plurality of guide members into alignment with the tab cutting mechanism to selectively control the dimensional characteristics of tabs formed in a moving sheet of battery cell foil. [2] The system of claim 1, wherein the tab cutting mechanism comprises a laser. [3] The system of claim 1, wherein the web roll comprises a cylinder having a first end and a second end defining a web roll axis, the surface being defined between the first end and the second end. [4] The system of claim 3, wherein the guide member support member is disposed at the first end and is rotatable about the web roller axis. [5] The system of claim 4, wherein the plurality of guide elements comprises a first guide element having a first dimension defined along the web roll axis, a second guide element having a second dimension defined along the web roll axis and greater than the first dimension, and a third guide element having a third dimension defined along the web roll axis and greater than the second dimension. [6] The system of claim 1, wherein each of the plurality of guide members is circumferentially spaced from others of the plurality of guide members along the guide member support member. [7] A method for forming tabs in a battery cell foil, comprising: Guiding the accumulator cell foil over a web roller with a web roller axis, Carrying a part of the battery cell foil on a guide element carrier part comprising a plurality of guide elements, Directing a tab cutting mechanism to a first of the plurality of guide elements, Cutting a first tab into the portion of the battery cell foil, the first tab having a first dimension corresponding to the first of the plurality of guide elements, Moving the guide element support member while the battery cell foil is being fed over the web roller to align a second of the plurality of guide elements with the tab cutting mechanism, and Cutting a second tab into the portion of the battery cell foil, the second tab having a second dimension different from the first dimension and corresponding to the second of the plurality of guide elements. [8] The method of claim 7, wherein aligning the tab cutting mechanism comprises directing a laser at the first of the plurality of guide elements. [9] The method of claim 7, further comprising further translating the guide member support member while the battery cell foil is being fed over the web roller to align a third of the plurality of guide members with the tab cutting mechanism. [10] The method of claim 7, wherein moving the guide member support member comprises rotating the guide member support member relative to the web roller.

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