Labeless electrode for battery cell

Abstract

A battery cell includes a housing encapsulating an anode and a cathode, and an electrode assembly disposed in the housing, the electrode assembly including a plurality of electrode layers forming a cell stack. Each electrode layer has a coated portion forming a portion of the cell stack and an uncoated connection portion extending away from the cell stack, the coated portion having a first height, the uncoated connection portion configured to be electrically connected to another electrode layer, the uncoated connection portion having a second height equal to the first height.

Description

Technical Field

[0001] The present disclosure relates to batteries, and more particularly, to the manufacture and assembly of battery cells. Background Art

[0002] Battery cells are used in various applications, such as automotive applications (e.g., in electric and hybrid vehicles). For example, electric and hybrid vehicle battery systems include battery modules having a plurality of battery cells. The battery cells can be pouch-type battery cells, prismatic battery cells, or other types of battery cells, and include multiple layers of anode material and cathode material. Each electrode includes a coated metal foil and tabs for electrically connecting the electrodes. The anode layers are electrically connected by welding the stacked anode tabs, and the cathode layers are electrically connected by welding the stacked cathode tabs. Typically, the tabs are formed by slitting or cutting the metal foil material. Summary of the Invention

[0003] In one exemplary embodiment, a battery cell includes a housing encapsulating an anode and a cathode, and an electrode assembly disposed in the housing. The electrode assembly includes a plurality of electrode layers forming a battery cell stack. Each electrode layer has a coated portion forming part of the battery cell stack and an uncoated connection portion extending away from the battery cell stack. The coated portion has a first height, and the uncoated connection portion is configured to be electrically connected to another electrode layer and has a second height equal to the first height.

[0004] In addition to one or more features described herein, the coated portion includes active material coating the surface of the coated portion.

[0005] In addition to one or more features described herein, the uncoated connection portion extends away from the battery cell stack by a length selected to allow the uncoated connection portion to be connected to a terminal.

[0006] In addition to one or more features described herein, the length is less than or equal to 5 mm.

[0007] In addition to one or more features described herein, the electrode layer is formed by: obtaining a sheet of conductive material, coating a first portion of the sheet of conductive material to form the coated portion, and leaving a second portion of the sheet of conductive material uncoated to form the uncoated portion.

[0008] In addition to one or more features described herein, the uncoated portion is formed without removing any conductive material of the sheet.

[0009] In addition to one or more features described herein, the housing is a rectangular prismatic housing.

[0010] In addition to one or more features described herein, the battery cell is configured to be mounted in a battery assembly having a plurality of battery cells and is configured to be disposed in a vehicle to provide power for propulsion of the vehicle.

[0011] In another exemplary embodiment, a method of manufacturing a battery cell includes obtaining a sheet of electrode material; partially coating the sheet of electrode material with an active material, the partial coating resulting in a coated region and an uncoated region of the sheet of electrode material; and forming a plurality of electrode layers from the sheet of electrode material by defining a plurality of portions, each portion having a coated portion and an uncoated portion. The method further includes assembling the plurality of portions such that the coated portions define electrode layers in a battery cell stack having a first height and the uncoated portions define uncoated connection portions extending away from the battery cell stack, the uncoated connection portions having a second height equal to the first height.

[0012] In addition to one or more features described herein, the uncoated connection portions are defined without removing any electrode material from the corresponding portions of the sheet.

[0013] In addition to one or more features described herein, the method includes electrically connecting the plurality of electrode layers by welding the plurality of uncoated connection portions to terminals and mounting the connected electrode layers in a housing.

[0014] In addition to one or more features described herein, the housing is a rectangular prism-shaped housing.

[0015] In addition to one or more features described herein, electrically connecting the plurality of electrode layers includes folding the uncoated connection portions against the terminals.

[0016] In addition to one or more features described herein, each uncoated connection portion extends away from the battery cell stack a length selected to permit each uncoated connection portion to be connected to a terminal.

[0017] In addition to one or more features described herein, the length is less than or equal to 5 mm.

[0018] In yet another exemplary embodiment, a vehicle system includes a battery assembly, the battery assembly including a battery cell, the battery cell including a housing encapsulating an anode and a cathode. The battery cell includes an electrode assembly disposed in the housing, the electrode assembly including a plurality of electrode layers forming a battery cell stack, each electrode layer having a coated portion forming part of the battery cell stack and an uncoated connection portion extending away from the battery cell stack, the coated portion having a first height, the uncoated connection portion configured to be electrically connected to another electrode layer, the uncoated connection portion having a second height equal to the first height.

[0019] In addition to one or more features described herein, the coated portion includes an active material coating a surface of the coated portion.

[0020] In addition to one or more of the features described herein, the uncoated connection portion extends away from the battery cell stack for a length that is selected to permit the uncoated connection portion to be connected to a terminal.

[0021] In addition to one or more of the features described herein, the electrode layer is formed by obtaining a sheet of conductive material, coating a first portion of the sheet of conductive material to form a coated portion, and leaving a second portion of the sheet of conductive material uncoated to form an uncoated portion.

[0022] In addition to one or more of the features described herein, the uncoated portion is formed without removing any of the conductive material of the sheet.

[0023] The above and other features and advantages of the present disclosure will become apparent when the following detailed description is read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, advantages, and details appear only by way of example in the following detailed description, which refers to the accompanying drawings, in which:

[0025] Figure 1 An example of a prismatic battery cell is depicted;

[0026] Figure 2A and 2B A battery cell stack and an uncoated connection portion of a battery cell according to an exemplary embodiment are depicted, the uncoated connection portion being electrically connected to a terminal;

[0027] Figure 3A and 3B Components of an example of a conventional battery cell are depicted;

[0028] Figure 4 A system for manufacturing a battery cell according to an exemplary embodiment is depicted;

[0029] Figure 5 is a flowchart of a method for manufacturing a battery cell according to an exemplary embodiment;

[0030] Figure 6 An example of a conductive sheet for manufacturing an electrode layer according to an exemplary embodiment is depicted;

[0031] Figure 7 A motor vehicle including a battery system according to an exemplary embodiment is depicted; and

[0032] Figure 8 A computer system for performing aspects of a manufacturing process according to an exemplary embodiment is depicted. DETAILED DESCRIPTION

[0033] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. It should be understood that in all the figures, corresponding reference numerals denote the same or corresponding parts and features.

[0034] According to one or more exemplary embodiments, methods, apparatuses, and systems are provided for facilitating the attachment and electrical connection of electrodes (anodes and cathodes) in a battery cell. Embodiments of the battery cell include electrodes disposed in a housing as a plurality of anode layers and a plurality of cathode layers. These layers may be sheets or foils made of a conductive material forming a battery cell stack, and each layer includes a portion, referred to as a “connection portion,” that permits stacking and welding of the layers. Each connection portion extends a selected distance away from the battery cell stack such that the connection portions can be welded or otherwise electrically connected.

[0035] In one embodiment, the size of each connection portion is equal to the size of the corresponding layer in the battery cell stack. For example, the battery cell stack is a rectangular stack disposed in a rigid housing (such as a prismatic can or housing) having a height and a length. Each layer has a “stacking portion” that forms part of the battery cell stack and an integral connection portion. The connection portion and the stacking portion have the same height.

[0036] As used herein, dimensions are “equal” to each other when they are at least substantially the same. For example, due to the precision of manufacturing tools or processes and / or due to built-in tolerances, the height of the connection portion may have a slight difference from the height of the stacking portion.

[0037] Embodiments also include a process or method for manufacturing the battery cell. For example, the manufacturing process includes obtaining sheets of electrode material (such as copper and aluminum). Each sheet is coated with an active material, leaving a portion of the sheet uncoated. The uncoated portion serves as the connection portion without the need to cut off tabs.

[0038] The embodiments described herein present numerous advantages and technical effects. These embodiments provide an improved manufacturing process that facilitates the correct attachment and electrical connection of electrode tabs while reducing unused or dead volume. Additionally, the electrode layers and connection portions can be formed without the need for cuts or incisions, thereby reducing time and complexity in the manufacturing process. Further, the embodiments provide a more uniform current distribution compared to traditional tabs.

[0039] Figure 1depicts an example of a battery cell 10. The battery cell includes a housing 12, which can be a rigid housing (such as a drawn aluminum housing) that is sealed to encapsulate a plurality of electrodes. For example, the battery cell 10 is a prismatic battery cell having a rectangular housing 12. The housing 12 can be made of any suitable material. The embodiments described herein are not limited to any particular type of battery cell, or any particular shape, size, or material of the electrodes and the housing. For example, the embodiments can be applicable to pouch-type battery cells and other types of battery cells.

[0040] The battery cell 10 includes a plurality of negative electrodes or anode layers 14 and a plurality of positive electrodes or cathode layers 16. The anode layers and the cathode layers are separated by an insulating layer or separator 18. The different layers form a battery cell stack 20.

[0041] The anode and the cathode are made of a selected conductive material and configured as sheets or foils. Each anode layer 14 includes a conductive substrate 22 (such as a copper sheet) and an active material coating 24 on each side of the substrate 22. Similarly, each cathode layer 16 includes a conductive substrate 32 (such as an aluminum sheet) and an active material coating 34 on each side of the substrate 32.

[0042] The active material can be any suitable material. For example, the anode coating 20 can be made of graphite or other carbon materials and other materials such as silicon and silicon oxide, and the cathode coating can be made of a lithium metal oxide or other suitable lithium materials.

[0043] Note that the number of electrodes is not limited to Figure 1 the number shown. The battery cell 10 can have any number of anode layers 14 and any number of cathode layers 16. For example, the battery cell may have hundreds of individual foil layers forming the electrodes.

[0044] As Figure 1 shown, each anode layer 14 includes a portion 26 that extends away from the interior of the battery 10 or the battery cell stack 20 and allows each anode layer 14 to be electrically connected to another anode layer 14. This portion is referred to as the connection portion 26 and is an uncoated portion (i.e., a portion made only of copper or other suitable conductive material) that extends a length L from the battery cell stack 20.

[0045] Each cathode layer 16 includes an uncoated connection portion 36 that extends away from the battery cell stack 20 and allows the cathode layers 16 to be electrically connected to each other. The uncoated connection portion 36 (i.e., a portion made specifically of aluminum or other suitable conductive material) extends a length L from the battery cell stack 20. The uncoated connection portion 36 can have the same length as the uncoated connection portion 26, or a different length.

[0046] Figure 2A and 2B depicts an example of a battery cell 10. Figure 2AShows the respective layers that make up the battery cell stack 20 and the connection portions 26, Figure 2B Shows the battery cell stack 20 electrically connected to the battery terminals 29 and 39. The battery cell stack 20 has a height H. In this example, the battery cell stack 20 and a set of internal terminals 29 and 39 are disposed within the housing 12.

[0047] As Figure 2A shown, the connection portions 26 and 36 each have the same (or similar) height as the battery cell stack 20, and the distance (length L) extending from the battery cell stack is significantly less than the length of a conventional tab. The heights of the connection portions 26 and 36 can be the same as the height of the battery cell stack 20.

[0048] Figure 2B Shows the battery cell stack 20 electrically connected to a connector (such as a welding plate or terminal). For example, the uncoated connection portion 26 of the anode layer 14 is assembled into a connection stack 28, which is folded and welded to an anode terminal assembly including the anode terminal 29 and the connector 31. The uncoated connection portion 36 of the cathode layer 16 is assembled into a connection stack 38, which is folded and welded to a cathode terminal assembly including the cathode terminal 39 and the connector 41.

[0049] The anode connection stack 28 defines a folded thickness T between the battery cell stack 20 and the anode terminal when folded A . The cathode connection stack 38 defines a folded thickness T when folded C . The folded thicknesses can be substantially the same and are significantly less than the folded thickness of a conventional tab stack. For example, the sum of the folded thicknesses T A and T C is from about 100 microns to about 2 millimeters.

[0050] Figure 3A And 3B Depicts an example of a battery cell 40 including a conventional connection tab. As Figure 3A shown, the battery cell 40 includes a battery cell stack 42, which includes an anode layer 44, a cathode layer 46, and a separator 48. The anode layer 44 is connected to an anode tab 50, and the cathode layer 46 is connected to a cathode tab 52.

[0051] Figure 3B Shows the internal components of the battery cell 40. The anode tab 50 is folded to form a tab stack 53 and is welded to an anode terminal assembly including the anode terminal 54 and the connector 55. The cathode tab 52 is folded to form a tab stack 57 and is welded to a cathode terminal assembly including the cathode terminal 56 and the connector 59.

[0052] Compared with a conventional tab, Figure 1The connecting portions 26 and 36 provide a more uniform current distribution and also reduce the volume required to stack and connect the tabs to the terminals. For example, the length L (e.g., 3 - 5 mm) of the connecting portions 26 and 36 is significantly less than the distance (e.g., 5 - 30 mm) defined by the conventional tab stacks 53 and 57. In addition, the height H of the connecting portions 26 and 26 is the same as the height of the battery cell stack 20, providing sufficient surface area for current distribution.

[0053] As a result, the volume required to stack, fold, and electrically connect the battery cell stack to the terminals or other conductors is significantly reduced. For example, Figure 2B the thickness T A and T C is much less than Figure 3B the folded thickness (denoted as T F ) of the conventional battery cell 40 shown. In addition, compared to the connecting portions 26 and 36, the conventional tabs 50 and 52 leave a large amount of unused volume when stacked and welded.

[0054] Figure 4 FIG. depicts an example of a manufacturing system 60 for manufacturing battery cells. The manufacturing system 60 includes various manufacturing stations that can be controlled or operated by a computer system, an operator, or a combination thereof.

[0055] As used herein, a "station" refers to any number, combination, and layout of equipment and is not intended to limit the manufacturing system 60 to any particular machine or combination of machines.

[0056] The manufacturing system includes, for example, an active material processing station 62 for preparing the active material to be applied to the electrode substrate. The system 50 may also include a coating station 64 for coating the electrodes with the active material. As used herein, the station 64 can be used to partially coat a sheet of electrode material.

[0057] The manufacturing system 60 also includes a cutting station 66 that can be used to form the portions that define the electrode layers and the connecting portions. These portions can be formed in any suitable manner, such as by laser cutting, stamping, punching, etc.

[0058] The system 60 can include other stations for performing subsequent processes to complete the battery cell. Examples include a stacking station 68, a welding station 70, and an assembly station 72 (e.g., for battery cell encapsulation, sealing, electrolyte filling, etc.).

[0059] The manufacturing system 60 can include additional stations for manufacturing battery assemblies (e.g., battery packs and / or modules). For example, the battery cells can be installed in a battery assembly. The battery assembly can be a battery module having a plurality of electrically connected battery cells, such as a battery module incorporated as part of a vehicle (e.g., an electric or hybrid vehicle).

[0060] Figure 5 An embodiment of a method 80 for manufacturing a battery cell, such as battery cell 10, is shown. Method 80 (or portions thereof) may be performed by any suitable one or more processing devices, such as a controller of manufacturing system 50, but is not limited thereto.

[0061] Method 80 includes a plurality of steps or stages represented by blocks 81 - 86. Method 80 is not limited to the number or order of the steps, as some of the steps represented by blocks 81 - 86 may be performed in a different order than described below, or a sequence of less than all the steps may be performed.

[0062] At block 81, a sheet of conductive material is obtained for forming an electrode layer. For example, a long copper sheet (or other suitable material) is obtained and referred to as the "anode sheet", and a long aluminum sheet or other suitable material is obtained and referred to as the "cathode sheet". These sheets serve as a substrate for subsequent coatings.

[0063] At block 82, the anode sheet and the cathode sheet are coated with an active material. The active material may be a metal oxide, such as lithium cobalt oxide (LCO), lithium nickel manganese cobalt oxide (NMC), or lithium iron phosphate (LFP). The anode sheet and the cathode sheet are partially coated, leaving uncoated portions that will form connection portions.

[0064] At block 83, the anode sheet is processed to produce a plurality of individual anode layers (such as anode layer 14), and the cathode sheet is processed to produce a plurality of individual cathode layers (such as cathode layer 16). The anode layers and the cathode layers are stacked in an alternating pattern with separator layers. For example, the sheets are cut into rectangular portions and stacked, or the sheets are rolled up or wrapped to form layers (and may subsequently be cut to fit the housing).

[0065] Figure 6 An example of a cathode sheet for forming cathode layer 16 is shown. A similar anode sheet may be used to form the anode layer.

[0066] The cathode sheet 90 is fed into a coating device (such as Figure 4 coating station 64 thereof), where a portion 92 is coated with an active material. The sheet 90 is only partially coated, leaving an uncoated portion 94 that will form connection portion 36 of the cathode layer. After coating, the sheet 90 is divided into a plurality of portions 96 (shown in dashed lines). Each portion has a respective dimension H that will correspond to the height H of the cathode layer. The sheet 90 may be formed into layers by cutting the sheet before stacking or by wrapping the sheet 90. No incisions or cuts are required to form the connection portion.

[0067] Referring again to Figure 5, at block 84, the uncoated connection portions of the anode layer are electrically connected by welding, and the uncoated portions of the cathode layer are similarly connected. For example, the uncoated anode connection portions 26 are stacked together and welded to a terminal or a welding plate (such as terminal 29), and the uncoated anode connection portions 36 are stacked together and welded to a terminal or a welding plate (such as terminal 39). Before welding, the stacked portions can be folded as needed to conform to their respective terminals and eliminate any dead spaces.

[0068] At block 85, additional steps are performed to complete the assembly of the battery cell, such as mounting the welded electrodes in a housing (such as a prismatic housing), quality inspection, electrolyte filling, housing sealing, etc.

[0069] At block 86, the battery cell can be installed in a battery assembly, such as a battery pack or a battery module. For example, the battery cell is installed in a battery module with other battery cells, and the battery module is installed in an electric or hybrid vehicle.

[0070] Note that the manufacturing system 60 and method 80 are not intended to limit the embodiments to any specific manufacturing process. Any suitable manufacturing system or process including some form of electrode manufacturing and electrical connection can be used.

[0071] The embodiments of the battery cell described herein can be connected to or be a part of a vehicle battery system. Figure 7 An embodiment of a motor vehicle 110 is shown, which includes a body 112. The vehicle 110 can be an internal combustion engine vehicle, an electric vehicle (EV), or a hybrid electric vehicle (HEV). In one example, the vehicle 110 is a hybrid or electric vehicle with an electric motor 114. The battery system 116 is electrically connected to the motor 114 and / or other components, such as vehicle electronics. The battery system 116 includes one or more modules 120, and each module 120 defines or is a part of a high-voltage battery pack. The module 120 includes a plurality of battery cells 10.

[0072] The vehicle 110 also includes one or more processing devices, such as a controller 118. The controller 118 can perform various functions, such as controlling conversion devices (such as one or more inverters and / or one or more direct current (DC)-DC converters), controlling components of a battery management system, monitoring the motor 114 and / or the battery system 116, etc. The controller 118 can include a non-transitory computer-readable medium storing instructions that, when processed by one or more processors of the controller 118, implement a method for operating vehicle components and systems as needed.

[0073] Figure 8Aspects of an embodiment of a computer system 140 are shown, which can execute various aspects of the embodiments described herein. The computer system 140 includes at least one processing device 142, which generally includes one or more processors for executing aspects of the image acquisition and analysis methods described herein.

[0074] The components of the computer system 140 include a processing device 142 (such as one or more processors or processing units), a memory 144, and a bus 146 that couples various system components, including the system memory 144, to the processing device 142. The system memory 144 can be a non-transitory computer-readable medium and can include various computer system-readable media. Such media can be any available medium accessible by the processing device 142 and includes volatile and non-volatile media as well as removable and non-removable media.

[0075] For example, the system memory 144 includes non-volatile memory 148 such as a hard disk drive and can also include volatile memory 150 such as random access memory (RAM) and / or cache memory. The computer system 140 can also include other removable / non-removable, volatile / non-volatile computer system storage media.

[0076] The system memory 144 can include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments described herein. For example, the system memory 144 stores various program modules that generally execute the functions and / or methods described herein. One or more modules 152 can be included to perform functions related to controlling one or more manufacturing processes. The system 140 is not limited thereto, as other modules can be included. As used herein, the term "module" refers to a processing circuit that can include an application-specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or grouped) that executes one or more software or firmware programs, and memory, combinational logic circuitry, and / or other suitable components that provide the described function.

[0077] The processing device 142 can also communicate with one or more external devices 156 that are a keyboard, a pointing device, and / or any device that enables the processing device 142 to communicate with one or more other computing devices (such as a network card, a modem, etc.). Communication with the various devices can be through input / output (I / O) interfaces 164 and 165.

[0078] The processing device 142 may also communicate with one or more networks 166 via the network adapter 168, such as a local area network (LAN), a general wide area network (WAN), a bus network, and / or a public network (such as the Internet). It should be understood that although not shown, other hardware and / or software components may be used in conjunction with the computer system 40. Examples include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, and data archival storage systems, etc.

[0079] The terms "a" and "an" do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. The term "or" means "and / or" unless the context clearly dictates otherwise. References throughout the specification to "one aspect" mean that a particular element (e.g., a feature, a structure, a step, or a property) described in connection with that aspect is included in at least one aspect described herein, and may or may not be present in other aspects. Additionally, it should be understood that the described elements may be combined in any suitable manner in the various aspects.

[0080] When an element such as a layer, a film, a region, or a substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, no intervening elements are present.

[0081] Unless stated to the contrary herein, all test standards are the latest valid standards as of the filing date of the present application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0082] Unless otherwise defined, the 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 pertains.

[0083] Although the foregoing disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various changes may be made and equivalents may be substituted for its elements without departing from its scope. Additionally, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Accordingly, it is intended that the disclosure not be limited to the particular embodiments disclosed, but that it will include all embodiments falling within its scope.

Claims

1. A battery cell, comprising: A casing encapsulating the anode and cathode; as well as An electrode assembly is arranged in a shell, the electrode assembly includes a plurality of electrode layers forming a battery cell stack, each electrode layer having a coated portion forming a part of the battery cell stack and an uncoated connecting portion extending away from the battery cell stack, the coated portion having a first height, the uncoated connecting portion being configured to be electrically connected to another electrode layer, and the uncoated connecting portion having a second height equal to the first height.

2. The battery cell according to claim 1, wherein: The coating portion includes an active material coating a surface of the coating portion.

3. The battery cell according to claim 1, wherein: The uncoated connecting portion extends away from the battery cell stack by a length selected to allow the uncoated connecting portion to be connected to a terminal.

4. The battery cell according to claim 3, wherein: The length is less than or equal to 5 mm.

5. The battery cell according to claim 3, wherein: The electrode layer is formed by taking a conductive material sheet, coating a first portion of the conductive material sheet to form a coated portion, and leaving a second portion of the conductive material sheet uncoated to form an uncoated portion.

6. The battery cell according to claim 5, wherein: The uncoated portion is formed without removing any conductive material of the sheet.

7. The battery cell according to claim 1, wherein: The housing is a rectangular prism-shaped housing.

8. The battery cell according to claim 1, wherein: The battery cell is configured to be mounted in a battery assembly having a plurality of battery cells and is configured to be disposed in a vehicle to provide power for propulsion of the vehicle.

9. A method for manufacturing a battery cell, comprising: obtaining an electrode material sheet; partially coating the electrode material sheet with an active material, the partial coating resulting in coated areas and uncoated areas of the electrode material sheet; forming a plurality of electrode layers from a sheet of electrode material by defining a plurality of sections, each section having a coated portion and an uncoated portion; as well as The plurality of portions are assembled such that the coated portion defines an electrode layer in a battery cell stack having a first height, and the uncoated portion defines an uncoated connecting portion extending away from the battery cell stack, the uncoated portion defining an electrode layer in a battery cell stack having a first height.

10. The method according to claim 9, wherein: Without removing any electrode material from the corresponding portion of the sheet, an uncoated connecting portion is defined.

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