KR20200053463A - Stacked prismatic architecture for electrochemical cells - Google Patents

Abstract

A battery cell system and method for manufacturing a battery cell system are provided. The battery cell system includes a first anode having a first anode tab, a second anode having a second anode tab transversely offset from the first anode tab, a first cathode having a first cathode tab, and a first cathode tab. And an electrode stack comprising a second cathode having a second cathode tab transversely offset.

Description

Stacked prismatic architecture for electrochemical cells

Cross-reference to related applications

This application claims priority to U.S. Provisional Application No. 62 / 520,478 filed June 15, 2017 in the name of "STACKED PRISMATIC ARCHITECTURE FOR ELECTROCHEMICAL CELL". The entire contents of the applications listed above are hereby incorporated by reference for all purposes.

The present application relates to a battery cell system and a method for manufacturing the battery cell system.

Searching for cost-effective solutions to increase battery capacity is an important challenge. As kWh-per-kWh continues to decline for battery electrochemical storage, larger and higher capacity batteries that can also be used for high-power applications There is a need to build. Many types of electrochemical cells have electrodes in the form of a 'sheet', where sheets of positive and negative electrode materials are stacked together, and electrically insulating porous separator sheet ). In order to increase the overall capacity of the cell (eg, total available energy), close contact between sheets or electrodes may be required.

A large geometric surface area may be required for high-power, low-impedance electrochemical cells with stacked prismatic cell architecture. In manufacturing a typical battery comprising a stacked prismatic cell, a stack is placed on layers of electrode cells that may contain lithium-ion or other electrochemical materials useful for secondary batteries or secondary cells. Is formed by. When the electrodes in the electrode stack are kept in close contact with each other throughout the life of the cell, the battery can achieve the desired capacity. However, when the electrode stack achieves less than required contact between the sheets, the tension between the sheets or between the seats and the battery housing is the gas generated in the battery during cycling of the battery. Can be caused by In order to increase the battery capacity and provide the desired electrode stack, many solutions have been proposed.

One proposed example is shown in US 8,133,609. Here, a battery comprising a plurality of cells or plates has tabs from each cell welded to a lead portion, the leading portion being protected by an enclosure. Another example is shown in US 6,159,631. Here, various scored areas located on a cell can or housing are provided to discharge excess pressure beyond a narrow and controllable range, in order to avoid explosion in the event of large battery expansion.

However, the inventors herein have identified potential issues in these systems related to the layering of battery cells, welding of battery cells, manufacturing and assembly of housings, and design and manufacture of exhaust or safe exhaust. For example, a normal battery with a high-power stacked prismatic cell has multiple layers of cells or electrode cells. The number of layers is limited by the welding technique used to weld the tabs or electrodes of each layer together. In particular, the number of electrodes included in the cell is limited by the durability of the electrode tabs when exposed to the energy of the welding. Accordingly, as the number of electrodes increases, and therefore, the weld intensity required to weld all of the electrodes increases, the electrodes are more likely to deteriorate (eg, melting, deformation, etc.). Can be. For example, current fabrication techniques use large electrode dimensions and layer counts, often in the range of less than 60 layers, and typically 20 to 30 layers. Additionally, the thickness of the cell can be limited to 15 mm due to the manufacturing limitations of the housing.

In addition, the housing imposes additional restrictions that limit the depth at which the housing material can be formed. Often, the housing is formed from aluminum, and the shape of the housing is formed from aluminum sheet metal in a manner similar to the way sheet metal is stamped. However, during existing housing forming processes, aluminum or other housing material is stretched and its thickness is reduced, thereby reducing the strength of the material. Additionally, previous secondary or rechargeable batteries do not include safety valves or gas-discharge devices for handling catastrophic failure of one or more battery cells.

In one embodiment, some of the above issues include a first anode having a first anode tab, a second anode having a second anode tab transversely offset from the first anode tab, a first cathode tab It can be solved at least in part by a battery cell system comprising an electrode stack comprising a first cathode having a second cathode and a second cathode having a second cathode tab transversely offset from the first cathode tab. By offsetting the tabs of electrodes of similar polarity, the number of electrode tabs in the welded group can be reduced if desired. As such, the number of electrodes included in the cell can be increased without excessively increasing the thickness of the groups of electrode tabs. As a result, the risk of electrode tab deterioration (eg, deformation, melting, etc.) caused by increased intensity welding can be reduced. In this way, higher power cells with increased durability can be achieved if desired.

1 shows an example of a prior art electrochemical cell.
2A and 2B show cathodes and anodes, respectively, in a battery cell system.
3 shows the coated sheet material of the anode in a battery cell system.
4 shows the coated sheet material of the cathode in a battery cell system.
5 shows an electrode stack with interleaved tabs in a battery cell system.
6 shows an electrode stack with trimmed tabs for welding in a battery cell system.
7 shows an electrode stack with welded extension tabs in a battery cell system.
8 shows an electrode stack with a top frame in a battery cell system.
9 shows a structural frame with a stack assembly in a battery cell system.
10 shows an electrode stack with a structural frame in a battery cell system.
11 shows a structural frame sidewall designed for strain relief in a battery cell system.
12 shows a protective housing surrounding an electrode stack in a battery cell system.
13A and 13B show different views of the protective housing in the battery cell system.
14 shows another view of a protective housing in a battery cell system.
15 shows a welded electrode stack in a battery cell system.
16 shows the top of the pouch with a charge or exhaust port in a battery cell system.
17 shows a rupture disc vent installed at a charge or exhaust port in a battery cell system.
18 shows an example of an electrode stack pattern in a battery cell system.
19 shows layers of a laminate pouch in a battery cell system.
20 shows a method for manufacturing a battery cell system.
If desired, other relative dimensions can be used, but FIGS. 2A-17 are drawn to scale.

The following description relates to a battery cell system having a stacked electrochemical cell battery (eg, a stacked prismatic electrochemical cell battery), and a method for manufacturing the battery cell system. It will be appreciated that FIGS. 2A-20 can be discussed collectively. 2A-15 show different aspects of the assembly of the battery cell system 550. 16-17 show example configurations of a protective housing in a battery cell system. 18 shows examples of layers in an electrode stack that can be included in a battery cell system. 19 shows examples of layers in a protective housing in a battery cell system. 20 shows a method for manufacturing a battery cell system. Also, axes X, Y, and Z are provided by reference in FIGS. 2A-17. In one example, the Z-axis can be parallel to the gravitational axis, and therefore can be referred to as a vertical axis. Additionally, the Y-axis can be a transverse axis and the X-axis can be a longitudinal axis. However, the axes can have alternative orientations in other examples.

The stacked cell battery described herein is an improvement over FIG. 1 (prior art). 1 of the prior art shows an example of an electrode stack 100 having a plurality of anode foil tabs 102 and cathode foil tabs 104. As shown in FIG. 1, anode foil tabs 102 are aligned transversely to each other. Cathode foil tabs are likewise aligned transversely to each other.

In the description herein, the anode is a positive electrode and the cathode is a negative electrode. The negative electrode will recognize that the existing current leaves the device through it, and the positive electrode will recognize that the existing current is the electrode entering the device through it. As such, anodes and cathodes may be generally referred to as electrodes, in some examples.

FIG. 3 shows an example anode 300 that may be included in an electrode stack, such as the electrode stack 500 shown in FIG. 5. The anode 300 can include an anode coating 302 coated on both sides of the anode electrode sheet 306 designed to collect current. The anode electrode sheet 306 can include a metallic foil substrate, and the coating 302 is a mixture of natural and artificial graphite or lithium-titanate, or an electrically active anode material such as metallic lithium (Eg, an electro-active lithium intercalation material). Accordingly, the anode 300 may include a metallic foil substrate (eg, anode electrode sheet 306) partially or wholly covered with a coating 302. The coating 302 can be applied on a specific portion of the anode electrode sheet 306, such as on a specific width of the anode electrode sheet 306, rather than all of the anode electrode sheet 306, so that the anode electrode sheet 306 At least a portion of the can remain uncoated. Accordingly, the anode 300 includes a coated section 304 comprising a coating 302, and an uncoated section 308 comprising an anode electrode sheet 306 and protruding from the coated section 304. can do. The coated sheet material can then be slit along alternating edges of the coated sections, exposing uncoated extending a certain width from the coated area on the edge of the electrode. It can result in a continuous electrode material having a foil.

FIG. 4 shows an example cathode 400 that may be included within the electrode stack 500 shown in FIG. 5. Cathode 400 may also be referred to as positive electrode 400 in some examples. In one example, cathode 400 may be similar in size and configuration to anode 300 (it may include similar dimensions and may be partially covered with a coating). However, in other examples, the cathode 400 may have a different size, shape, and the like from the anode. In addition, the cathode 400 is made of different materials than the anode 300. In particular, the cathode 400 is a mixture of a specially prepared Lithiated Iron-Phosphate powder or a Lithiated Metal-oxide powder, conductive carbon, and It may include a polymeric binder (polymeric binder). Specifically, the cathode 400 may include a cathode electrode sheet 406 coated in the cathode coating 402. Cathode electrode sheet 406 may also include a metallic foil current collector substrate similar to anode electrode sheet 306 of anode 300, but coating 402 may include different mixtures of specially prepared powders. In particular, the cathode coating 402 can include electrochemically active cathode materials such as specially prepared lithiated iron-phosphate powders or mixtures of lithiated metal-oxide powders, conductive carbons, and polymer binders referenced above. . Accordingly, the cathode 400 can be prepared in a similar manner to the anode 300, except that the anode and cathode coatings are different. Similar to the coating on the anode 300, the coating 402 can be applied on a specific portion of the electrode sheet 406, such as on a specific width of the electrode sheet 406, rather than all of the sheet 406, At least a portion of the sheet 406 may remain uncoated. Accordingly, the cathode 400 can include a coated section 404 comprising a coating 402 and an uncoated section 408 including an electrode sheet 406. The coated sheet material can then be slit along alternating edges of the coated sections, resulting in a continuous electrode material with exposed uncoated foil extending a certain width from the coated area on the edge of the electrode. Can result.

Accordingly, the uncoated portions of the electrode sheets 306 and 406 can extend beyond the coatings 302 and 402 and protrude from the coatings 302 and 402. As discussed in more detail herein, the protruding portions of the electrode sheets 306 and 406 can be trimmed under narrower tabs. After trimming, these narrowed, cut uncoated electrode areas can be referred to as electrode tabs (as described in more detail below). Accordingly, the trimmed electrode sheets 306 and 406 may be referred to as electrode tabs 212, 216, 220, and 224.

Accordingly, successive rolls of coated, calendered, and slitted electrodes 300 and 400 may be steel ruled die or close clearance-stamping. die) can be stamped to the desired dimensions using a normal stamping process. The stamped electrode shape can also be created by laser cutting. In prismatic prismatic cells, each of the first and second electrodes will have the same foil tabs remaining after stamping (see FIG. 1), so that when stacked into a cell electrode stack, the individual foil tabs 102 of the first electrode It will align all in a single position for one corner of the silver electrode stack. All stamped foil tabs 104 of the second electrode will likewise all align together in different single positions relative to the electrode stack corner.

Referring now to Figures 2A and 2B, as an improvement to the prior art mentioned above, a battery cell system is now disclosed. Successive rolls of coated, calendered, and slitted electrode materials are stamped to the desired dimensions using stamping techniques, but each of the cathodes and anodes 300 and 400 differs in the position of the remaining foil tab. It is stamped respectively with two different electrode dimensions, resulting in two different stamped cathodes 202 and 204 and two different stamped anodes 206 and 208. Stamped cathodes 202 and 204 may include electrode tabs 212 and 216, respectively. Accordingly, the first cathode 202 may include a first cathode tab 212, and the second cathode 204 may include a second cathode tab 216. Similarly, the first anode 206 can include a first anode tab 220, and the second anode 208 can include a second anode tab 224. As described in more detail herein, cathodes 202 and 204 and anodes 206 and 208 can be stacked to form an electrode stack (eg, electrode stack 500 shown in FIG. 5). . In particular, up to 150 electrodes (eg, cathodes 202 and 204 and / or anodes 206 and 208) can be stacked together to form an electrode stack. When stacked, the electrodes can be aligned with each other such that the ends of the electrodes are aligned. Accordingly, the first ends 201, 205, 211, and 215 of the electrodes 202, 204, 206, and 208 can be aligned, and the second ends 204, 207, 213, and 217 Can be aligned. However, the tabs 212, 216, 220, and 224 may be offset laterally from each other when the electrodes are stacked, so that the tabs 212, 216, 220, and 224 may not overlap each other. .

As described above, the cathode tabs 212 and 216 can extend from the cathode electrode sheet 406 that has been cut to the example dimensions shown in FIG. 2A. Accordingly, the cathode tabs 212 and 216 can have similar (eg, equivalent) compositions, except that they are laterally offset from each other when the cathodes 202 and 204 are aligned with each other. For example, it may have equivalent) size, shape, and / or geometry. In other words, the protruding electrode sheet 306 of the cathodes 202 and 204 can be cut differently, so that the resulting cathode tabs 212 and 216 are offset from each other, respectively, as shown in FIG. 5. It will not overlap when stacked. The cathodes 202 and 204 are stacked in an electrode stack (eg, electrode stack 500 shown in FIG. 5) by aligning the first ends 201 and 205 of the cathodes 202 and 204, respectively. Can be aligned with each other. As shown in the example of FIG. 2A, tabs 212 and 216 are closer to first ends 201 and 205 of cathodes 202 and 204, respectively, than second ends 203 and 207, respectively. Can be positioned. Offsetting groups of cathode tabs as well as anode tabs allows the thickness of the tab stacks to be reduced when compared to previous cell stacks where electrode tabs of similar charge are aligned. Reducing the thickness of the tab stack allows the energy used to weld the tab stacks to ultimately be reduced. As a result, the possibility of cell stack deterioration (eg, undesired deformation, melting, etc.) caused by increased weld strength can be reduced if desired. As a result, the size of the battery system can be increased without excessively increasing the thickness of the tab stacks beyond an undesirable value.

Accordingly, the cathode tab 212 can be spaced apart from the first end 201 of the cathode 202 by a distance defined by the first tap offset 210. Similarly, the cathode tab 216 can be spaced apart from the first end 205 of the cathode 204 by a distance defined by the second tap offset 214. However, the second tap offset 214 may be larger than the first tap offset 210 (eg, a larger distance). In this way, the tab 216 of the cathode 204 has a first end 205 of the cathode 204 than the cathode tab 212 of the cathode 202 spaced apart from the first end 201 of the cathode 202. ) Can be separated by a greater distance. In particular, the second tap offset aligns the first ends 201 and 205 and the second ends 203 and 207 with each other, such that when the cathodes 202 and 204 are aligned with each other, the tab 216 is a cathode. It may be sized so as not to overlap with any of the tabs 212.

2B shows the electrode tap spacing similar to the cathode tap spacing shown in FIG. 2A, except that FIG. 2B shows the electrode tap spacing for the anodes 206 and 208. Accordingly, unlike the tabs 212 and 216 of the cathodes 202 and 204, the anode tabs 220 and 224 of the anodes 206 and 208 have more anodes 206 than the first ends 211 and 215. And anode tabs 220 and 224 of anodes 206 and 208, similar to cathode tabs 212 and 216, except that they may be spaced closer to the second ends 213 and 217 of 208). (E.g., equivalent) size, shape, and / or geometry.

Accordingly, the electrode tab 220 can be spaced apart from the second end 213 of the anode 206 by a distance defined by the first tap offset 218. Similarly, anode tab 224 may be spaced apart from second end 217 of anode 208 by a distance defined by second tap offset 222. However, the second tap offset 222 may be larger than the first tap offset 218. In this way, the tab 224 of the anode 208 is the second end 217 of the anode 208, rather than the tab 220 of the anode 206 spaced from the second end 213 of the anode 206 It can be separated by a greater distance from. In particular, the second tap offset 222 aligns the first ends 211 and 215 and the second ends 213 and 217 with each other, such that the tabs 224 when the anodes 206 and 208 are aligned with each other. ) May be sized such that it does not overlap any of the tabs 220.

When the tabs are offset, the lateral faces 250 of the offset tabs are spaced apart from each other such that they are transversely separated. Also, the top faces 252 of the tabs shown in FIGS. 2A and 2B have a similar height. However, in other examples, the top faces 252 of the tabs can have non-equal heights. Further, in other examples, the first group of anode taps may be offset from the second group of anode taps by an amount different from the offset between the groups of cathode taps.

During the electrode stacking process, two different cathodes 202 and 204 and two different anodes 206 and 208 can be alternately stacked and separated by an insulating porous separator material. The lateral offset between stamped tabs of electrodes of the same polarity is determined from the sum of the tolerances for the stamping width and position and the stacked position tolerance of each electrode, so that a small gap is the electrode of each type. Can be maintained between tabs.

Referring now to FIG. 5, FIG. 5 shows a battery cell system 550 that includes an electrode stack 500 and a structural frame 501. Battery cell system 550 may also include a protective housing, such as laminate pouch 1200 shown in FIG. 12 and discussed in more detail herein. 5 also shows cathodes 202 and 204 and anodes 206 and 208 forming electrode stack 500. However, electrode stack 500 may, in one example, include first and second cathodes 202 and 204 and / or first and second anodes 206 and 208, respectively. It will be appreciated that in other examples, electrode stack 500 may include more than two anodes and / or cathodes.

The electrodes can be held in place by the structural frame 501. Accordingly, when stacked, the tabs 212, 216, 220, and 224 of the electrodes 202, 204, 206, and 208 can form four distinct groups of tabs, each of the groups being the same Tangible electrodes. However, in some examples, the foil tabs can be rearranged in any desired order. Accordingly, the first electrode tab group 502 may include the tab 212 of the first cathode 202, and the second electrode tab group 504 may include the tab 216 of the second cathode 204. The third electrode tab group 506 can include the tab 220 of the first anode 206, and the fourth electrode tab group 508 is the tab 224 of the second anode 208 ). Each of the groups 502, 504, 506, and 508 can include a plurality of individual types of electrode tabs, in some examples. Further, in some examples, each of the groups may include the same number of electrode tabs. However, in other examples, the groups can include different numbers of electrode tabs. For example, up to 150 electrodes may be stacked in the electrode stack 500. However, since the stack includes two different cathode tap groups offset from each other and two different anode tap groups offset from each other, the number of taps in each of the groups is such that all of the cathode taps are aligned with each other and the anode taps are It can be reduced when compared to approaches where all are aligned with each other.

In further examples, more than two offset anode and / or cathode tabs can be used in the electrode stack. Accordingly, more than two offset groups of positive and more than two offset groups of negative electrodes can be used in the electrode stack. By increasing the number of offset taps used in the electrode stack, the number of electrodes that can be included in the stack can be increased.

Assembling electrode stack 500 may, in one example, include using a specialized lamination machine. The specialized lamination machine includes a continuous sheet of 'Z' folding porous separator material around alternating stacked electrodes (eg, cathodes and anodes), beyond the edges of the separator on a single edge of the stack, or the electrode stack Results in a rectangular or prismatic shaped electrode stack 500 of alternating cathodes and anodes with four distinct groups of foil tabs extending from opposite sides of. For example, electrode stack 500 may be wrapped with a porous separator material after Z-wrapping alternating electrodes. The porous separator material allows the anodes and cathodes to be separated to reduce the possibility of unwanted interactions between the anodes and cathodes (eg, short circuit) while allowing the transport of ionic charge carriers do. It will be appreciated that other manufacturing techniques for electrode stack 500 can be considered.

After lamination, as shown in FIG. 5, the tabs of the tab groups 502, 504, 506, and 508 can be trimmed to a desired shape (eg, final shape) and shaped. , Bendable, foldable, and the like, an example of which is shown in FIG. 6. FIG. 6 shows the electrode stack 500 after removal from the lamination machine, where the electrode stack 500 is disposed in a structural frame 501 (eg, a holding fixture) and extends tab groups 502, 504, 506, and 508 are shaped and trimmed to the desired shape (eg, final shape) and dimensions they may have after welding the cell extension tab. As shown in FIG. 6, trimmed and shaped tab groups can be referred to herein as shaped tab groups 602, 604, 606, and 608. Accordingly, the tab groups 602, 604, 606, and 608 are tab groups 502, 504, 506, 508 that have been trimmed and shaped into a desired shape by prior art welding. Negative electrode groups 602 and 604 that include negative electrode tabs may be collectively referred to as cathode tabs 612, and positive electrode groups 606 and 608 collectively referred to as anode tabs 614. Can be. In some cases, a small ultrasonic pre-weld can be employed to keep the tabs in the desired shape for integrated and extended tap welding.

As shown in FIG. 6, the tab groups 502, 504, 506, and 508 are attached to the extended tabs as the resulting tabs 612 and 614 are shown and described in more detail herein with reference to FIG. It can be trimmed to include vertical welding surfaces 603 and 605, respectively, which can be directly welded.

6 shows the front side 650, the back side 652, the top side 654, the bottom side 656, the first transverse side 658, and the second transverse side 660 of the battery cell system 550. ) As well. The structural frame 501 may partially close the electrode stack 500. Specifically, the structural frame 501 extends below the front face 650, the back face 652, the first transverse face 658, and the second transverse face 660 of the system. In this way, the structural frame 501 can provide structural reinforcement to the battery cell system 550.

18, a typical stacking sequence for forming electrode stack 1800 in battery cell system 1850 is illustrated. The battery cell system 1850 may be an example of the battery cell system 550 illustrated in FIGS. 2A to 17. The electrode stack 1800 has the following pattern: separator material 1802 / first electrode 1804 / separator material 1802 / second electrode 1806 / separator material 1802 / third electrode 1808 / separator It may be arranged according to the material 1802 / the fourth electrode 1810 or the like. In this non-limiting example, elements 1804, 1806, 1808, and 1810 can correspond to any of the first and second positive and negative electrodes shown in FIGS. 2A and 2B. However, other stacking sequences were considered. It will also be appreciated that the cell stack pattern shown in FIG. 18 can be repeated as many times as desired. In some examples, the pattern can be repeated between 20 and 60 times. As an example indicated by the bottom separator material 1802 (bottom and top separated by arrows adjacent to the electrode stack), the stack may start at the top with a layer of separator material and the bottom (eg final) layer of separator material. It can be ended at the bottom.

As an example, referring to FIG. 18, a stacking sequence that may be employed repeatedly is a separator / first anode / separator / first cathode / separator / second anode / separator / second cathode. However, as mentioned above, other stacking sequences can be employed. Additionally, as an example, one or more stacking sequences may be used throughout the stack. As a further example, after stacking or repeating a stacking sequence or sequences a number of times, a layer of separator material can be used such that the stack starts and ends with the layers of separator material. As a further example, after lamination, the trailing edge of the separator can be taped in place to maintain its position during subsequent cell manufacturing steps.

Referring now to FIG. 7, after tab forming and trimming, each pair of at least two tab groups (eg, 612 and 614 in FIG. 6) includes a first extension tab 702 and a second extension tab ( 704), the width of the first and second extension tabs being at least equal to twice the sum of the electrode tab width and the gap between the two tab groups 612 and 614 in one example. Can be. Two separate ultrasonic welds are employed to integrate the two electrode tab groups into a single extension tab. Two welds can be achieved simultaneously in a single case, with a single welding horn. This welding can be performed on two groups of anode tabs, both on the anode extension tab, and also on two groups of cathode tabs and separately on the cathode extension tab. By way of example, two groups of anode tabs 614 can be welded to the anode extension tab 704 and two groups of cathode tabs 612 can be welded to the cathode extension tab 702. The extension tabs 702 and 704 allow different groups of offset tabs to be electronically coupled.

In some examples, tabs 612 and 614 can be sandwiched between extension tabs 702 and 704 and electrode tab supports 706 and 708, respectively. However, in other examples, the tabs can be welded directly to the extension tabs without electrode tab supports. In other examples, the individual tab groups 602 and 604 shown in FIG. 6, and then, the tab groups 606 and 608 shown in FIG. 6, are extended tabs 702 and 704 shown in FIG. 7 ). This process can be used to integrate the tab groups before adding the tab supports 706 and 708, and can provide a more robust electrode assembly.

The electrode tab supports 706 and 708 increase the structural integrity of the tab assembly, thereby reducing the possibility of tap damage occurring during battery use and / or manufacturing. As a result, the durability of the battery cell system is increased. The electrode tab supports 706 and 708 include slits 710 and 712, respectively, and in the illustrated example, through the slits 710 and 712, the extension tabs 702 and 704 can be extended. However, other electrode tab support profiles were considered. Additionally, in one example, electrode tab supports 706 and / or 708 can include an electrically insulating polymer material 714. Electrically insulating polymer material 714 may be designed to provide electrical isolation between extension tabs 702 and 704 and components such as the protective housing described in more detail herein. Further, in some examples, electrode tab supports 706 and 708 can be integrally formed with the protective housing, or are physically coupled directly to the protective housing.

Additionally, in one example, the cathode tabs 612 can include a nickel plated copper material, and the anode tabs 614 can include an aluminum material. However, additional or alternative material may be included in anode and / or cathode tabs in other examples.

Referring now to FIG. 8, after welding of the extension tabs, a structural frame 501 comprising an electrode stack is assembled. In one example, in a cell configuration with both positive and negative tabs on a single cell side, there can only be a single molded frame assembly on that side. In another example, if the tabs extend from opposite sides of the electrode stack, two molded frame assemblies can be used. The structural frame 501 can include at least one support 804 (eg, a polymer support). In the illustrated example, support 804 has a substantially triangular cross-section with chamfered edges to match the resulting shape of the laminate pouch packaging. However, other profiles of the support 804 were considered. Additionally, the support 804 includes two slots 805 and 807 sized to allow the extension tabs 702 and 704 to pass through the central region of the support. Structural frame 501 is, in one example, two matching frames that are then assembled onto the tabbed side of the cell by snap fit or press fit the two molded frame halves together. Can be made in half. Further, the support 804 may be injection molded in one example. Additionally, the support 804 has a triangular cross section in the Z-Y plane, in the illustrated example. Accordingly, the support 804 may be tapered in the vertical direction. However, other shapes of the support 804 have been considered and can be used in other examples. For example, the support 804 can have a rectangular cross-section, or the support can include curved (eg, convex or concave) sections. Further, the support 804 may be attached (eg, welded, adhesively bonded, mechanically coupled, combinations thereof, etc.) to the base 806 of the structural frame 501.

Referring next to FIG. 9, FIG. 9 provides mechanical separation of the electrode stack and tabs from the inner surfaces of the laminate pouch packaging material, thereby effecting, vibration, or during handling in a battery application environment or subsequent environmental exposure. Shown is an assembled structural frame 501 (e.g., inner box) that protects the pouch from mechanical damage and electrical isolation from impact. The structural frame can be fabricated into two separate halves 904 and 906 by injection molding, and assembled onto a welded electrode stack by press-fitting or snap-fitting. Additionally, further refinement of the structural frame can include a reduced thickness area 908 on one side 909 of the structural frame 501, thereby being heat sealed of a laminate pouch that can be applied in the next assembly step. Recessed grooves can be created to provide mechanical relief for the heat sealed seam. In one example, the structural frame 501 can be injection molded. However, other frame making techniques have been considered.

The structural frame 501 can then be packaged and / or vacuum sealed within the protective housing. In one example, the protective housing can be a laminate pouch, such as the laminate pouch 1200 shown in FIG. 12, having an internal protective structure with recessed shim relief grooves as described above. However, other types of protective housings such as housings with greater rigidity have been considered.

An example of a laminate pouch 1900 is shown in FIG. 19. It will be appreciated that the laminate pouch 1900 is an example of the previously described laminate pouch 1200 included in the cell battery system 550. The laminate pouch 1900 shown in FIG. 19 is heat sealed with at least one metallic layer having a non-aqueous electrolyte that reduces (eg prevents) moisture ingress into the finished electrochemical cell. It may include at least two layers to create a possible laminate, and in some examples, four functional layers. The innermost layer 1902 is another polymer layer 1906 (eg, a nylon layer) that can ultimately be bonded to the outer layer 1908 (eg, a polyethylene terephthalate (PET) layer) It can be a heat sealable polyolefin, such as polypropylene, bonded to an aluminum layer 1904 that can be bonded to. By way of example, the layers 1902, 1904, 1906, and 1908 can be rearranged as desired based on end-use design goals. The laminate pouch 1900 can be included in the battery cell system 1950. It will be appreciated that the battery cell system 1950 can be an example of the battery cell system 550 shown in FIGS. 2A-18. The laminate pouch 1900 may, in one example, include one or more walls to accommodate enlargement during electrolyte activation. Further, in this example, the walls of the laminate pouch can be substantially flat after electrolyte activation, and can be bent inward before electrolyte activation. In this way, the pouch can accommodate enlargement to reduce the possibility of pouch and / or cell damage.

Turning now to FIG. 10, as a further example, assembling the battery cell system 550 not only protects the electrode stack edges from mechanical damage during assembly and use, but also the external pressure created when the cell assembly is vacuum sealed. It is optional to first assemble the structural frame 501 around the outside of the welded electrode stack assembly to protect the electrode stack edges from (eg, at least 14.6 pounds per square inch (psi) pressure). It can contain as. The inner frame can include at least a protective frame disposed around the welded tab area of the electrode stack. The top face of the structural frame can have substantially triangular cross-sectional shapes and tapered edges 1002 and 1004 at the ends to match the shape of the folded pouch laminate packaging. Optionally, the structural frame 501 can be extended to prevent the edges and corners of the electrode stack from making direct contact with the inner surface of the pouch laminate material, thereby causing mechanical damage to the inner heat sealable polymer layer. The loss of internal electrical isolation can be prevented, and the aluminum layer can be exposed to electrical contact with electrochemically active electrodes.

In one example, the internal structural frame can be made of two matching halves with a stretchable gap between each half of the frame shown in FIGS. 9 and 10. The reduced thickness area 908 of the structural frame 501 allows the finished cell and electrode stack to be compressed in the normal thickness direction during the cell's electrochemical activation, formation, and degassing processes. This compression is formed as a byproduct of the cell's electrochemical forming processes, such as anode SEI formation, reaction with residual moisture in the cell, and / or other parasitic chemical reactions that produce gaseous byproducts, between the electrode and separator surfaces. It is applied as a means for removing gas bubbles. The stretchable gap further allows the cell thickness to increase / decrease during cell charging and discharging due to electrode expansion caused by an altered state of charge. Structural frames (eg, internally fabricated support frames) are chemically compatible polymers such as, for example, polypropylene, polyethylene, polybutylene terephthalate (PBT), and / or polyethylene terephthalate (PET). It can be produced by injection molding.

Turning now to FIG. 11, for example, to accommodate electrode stack expansion during cell electrolyte activation, formation, and use, the structural frame 501 and / or vertical sidewalls of the protective housing discussed in more detail herein ( 1104) can be tapered inward toward the center-line 1110 of the cell, allowing extra material to accommodate cell expansion and contraction. The extra material reduces the possibility of wrinkling and cracking in the battery cell system. During normal cycling of the battery, with cell expansion indicated by 1106, the extra material can provide strain relief to avoid damaging the center shim. The electrode stack and frame assembly can then be packaged in a laminate pouch. As a further example, the above-mentioned features of the tapered-inward faces of the structural frame 501 can be used to relieve pressure on other edges or faces of the battery. Accordingly, other edges or faces of the battery may have inward-tapered faces.

12, the battery cell system includes, in the illustrated example, a protective housing in the form of a laminate pouch 1200. However, as previously discussed, other suitable types of protective housings have been considered.

12, the laminate pouch 1200 can be formed in a rectangular cross-sectional shape, and one section (eg, end) can be folded and heat sealed. As such, the heat seam 1202, in the illustrated example, extends under the laminate pouch (eg, extends vertically). In this way, a closed end of the laminate pouch can be formed. In addition, the thermal shim 1202 can be aligned with the reduced thickness area 908 in the structural frame 501 shown in FIG. 10. In this way, the thermal shim 1202 can be paired with the reduced thickness area 908 in one example. However, it will be appreciated that the thermal shim 1202 can be positioned in other locations, in other examples.

Additionally, in some examples, a solid rectangular sizing fixture 1206 having the same dimensions as the electrode stack can be placed inside the laminate pouch to maintain the desired rectangular shape, while one end is It can be folded and heat sealed.

One example of an assembly sequence for a laminate pouch can be as follows: The laminate pouch material can be taken from a continuous roll and first rolled in the form of a tube with overlapping sections 2 to 20 mm wide. As an example, overlapping sections may be 10 mm wide. The overlapping section can be heat sealed using flat heating bars and can be folded flat against the unsealed surface.

Pouch folding may include, in one example, displacing a triangular shaped area on each of the two narrow sides of the pouch, compressing the long sides of the pouch in a direction perpendicular to the narrow sidewalls of the pouch. Additionally, the pouch 1200 can be selectively heat sealed along a narrow width adjacent the sidewall edges of the pouch package. The central area may, in some examples, be left unsealed at this stage to allow electrolyte filling during future assembly steps.

Turning now to FIGS. 13A and 13B, after folding and heat sealing the bottom closed end of the laminate pouch 1200, the rectangular sizing fixture 1206 can be removed, and the electrode stack and molded plastic frame assembly The tabs can be inserted facing away from the closed end of the pouch package. Corner triangular folds can be achieved in a manner similar to that of the lower closed end triangular folds. The top open end can be compressed, and the pouch can be heat sealed to both the electrode tab supports 706 and 708 and the opposing side of the pouch, creating a seal at the top tab end of the cell. Can be. The charging port can also be incorporated into this concept. This feature can be integrated as an injection molded protective frame, or as a separate part fused to a pouch material or frame. The surrounding area of the structural frame can be heat sealed to the inner polymer layer of the pouch, creating a leak tight seal. Additionally, the non-reamed end 1306 of the laminate pouch 1200 can be employed for cell filling and gas forming collection.

FIG. 14 shows an additional view of a laminate pouch 1200 with an additional non-reamed end 1306 of the laminate pouch.

15 shows an alternative view of an electrode welded stack before adding a structural frame or adding a protective housing (eg, a laminate pouch), before adding a structural frame or sizing fixture.

Turning now to FIG. 16, the port 1602 (eg, charging port) in the laminate pouch 1200 may be molded into internal or external threads, and the cell may be charged and / or electrolyte during the forming process. By being able to be used for outgassing, it is possible to reduce the quantity of pouch material used in manufacturing, as compared to current forming processes. In some cases, incorporation of a charge / degassing port can reduce the amount of pouch material used for the formation of a battery cell by 40% (compared to forming a battery cell without a charge / degassing port). The current forming process utilizes an integral gas volume formed of the extra length of the pouch material to create an extra internal void volume to accommodate the gases produced during the initial cell forming process. To create.

Returning to FIG. 17, the charging port mentioned above can incorporate the vent / burst disk 1702 in the laminate pouch 1200 that can help manage pressure relief, such that the operating conditions, or cell, are normal. Under extreme conditions that have been operated or handled outside operating conditions (eg, physical damage to the battery, exposure to extreme heat, etc.), controlled exhaust can be provided.

Referring to Figure 17, after formation, the cell can be vacuum degassed and sealed. In the current process, excess pouch material can be trimmed off and discarded during the vacuum sealing step. The cell can be evacuated through an integrated charging port during this degassing step. After degassing, the filling port can be sealed by several methods, such as a heat sealed plug or threaded plug. As an example, further improvements to cell safety under abuse conditions can be made, and a pressure relief vent is installed in the filling port sealing plug. The charging port can have a vent cap plug that will burst or open at a specified pressure to control the rate of gas ejection from the cell, such that an explosion or fire during exposure to abuse conditions Will reduce the probability of. Adding a plug or disk can incorporate the above mentioned sealing methods, in some cases, but not limited to heat sealing or threading. By way of example, the controlled exhaust can also incorporate indented or coined slits on the pouch to rupture before the heat seal fails. By way of example, carving or slitting a pouch can be added to any desired location on the pouch.

It should be understood that the drawings show an example configuration with relative positioning of various components. When depicted as being in direct contact with each other or directly coupled, such elements may be referred to as, in at least one example, direct contact or directly coupled. Similarly, elements depicted as neighboring or adjacent to each other may, in at least one example, be neighboring or adjacent to each other. By way of example, components placed to face-to-face contact with each other may be referred to as face-to-face contact. As another example, elements positioned apart from each other so that there is only space in between and no other components can be referred to as such in at least one example. As another example, elements shown above / below each other, on opposite sides of each other, or on the left / right side of each other may be referred to as relative to each other. Also, as shown in the figures, in at least one example, the top element or point of an element can be referred to as the “top” of the component, and the bottom element or point of the element is referred to as the “bottom” of the component. Can be. As used herein, the top / bottom, top / bottom, top / bottom may be for the vertical axes of the drawings, and may be used to describe the positioning of elements in the drawings relative to each other. As such, elements shown above other elements are, in one example, positioned vertically over other elements. As another example, the shapes of elements shown in the figures may be referred to as having those shapes (eg, circular, straight, planar, curved, hemispherical, chamfered, angular, etc.). In addition, elements shown crossing each other may be referred to as intersecting elements or crossing each other, in at least one example. Also, elements depicted within another element or depicted outside of another element may be referred to as such in one example.

20 shows a method 2000 for manufacturing a battery cell system. Method 2000 can be used to fabricate the battery cell systems described above with respect to FIGS. 2A-19. However, in other examples, the method can be used to manufacture other suitable battery cell systems. In addition, the method 2000 can be stored as instructions in memory (eg, non-transitory memory) executable by the processor.

In 2001, the method includes forming an electrode stack with offset anode tabs and offset cathode tabs. It will be appreciated that the electrode stack may, in some examples, include alternating cathodes and anodes with separator sheets positioned therebetween. Specifically, anodes and cathodes can be formed in the electrode stack in the following stacking sequence; A first anode, a first layer of porous separator material, a first cathode, a second layer of porous separator material, and the like. Forming the electrode stack can include steps 2002-2004.

In 2002, the method includes forming a plurality of anodes having a plurality of anode tabs, where the plurality of anode tabs includes a first group of anode tabs transversely offset from a second group of anode tabs.

Next, in 2004, the method includes forming a plurality of cathodes having a plurality of cathode tabs, wherein the plurality of cathode tabs comprises a first group of cathode tabs transversely offset from a second group of cathode tabs. Includes. Laterally offsetting the groups of cathode tabs as well as the groups of anode tabs allows the thickness of the tabs to be reduced when compared to a cell stack with aligned tabs. Therefore, the welding energy required to weld the groups of tabs can be reduced. As a result, the possibility of deterioration (eg, melting, deformation, etc.) of electrode tabs (eg, anode and cathode tabs) during welding is reduced.

In 2006, the method includes welding a first extension tab to a first group of anode tabs and a second group of anode tabs. Next, in 2008, the method includes welding the second extension tab to the first group of cathode tabs and the second group of cathode tabs.

Additionally, in some examples, the method can include steps (2010, 2012, 2014, and / or 2016). In 2010, the method includes attaching a first electrode tab support to a first group of anode tabs and a second group of anode tabs, and in 2012, the method includes attaching a second electrode tab support to a first group of cathode tabs and a cathode And attaching to a second group of tabs.

In 2014, the method includes placing the electrode stack in a structural frame. The structural frame may at least partially surround the electrode stack. In addition, in one example, the structural frame can include openings that allow the first and second support tabs to extend through it. Additionally, the structural frame can be molded from a polymer material, in one example.

In 2016, the method includes placing a structural frame and electrode stack within the protective housing. In one example, the protective housing can be a laminate pouch, and therefore, the method can include, in this example, folding the laminate pouch around the electrode stack and the support frame and heat sealing the laminate pouch. In one example, following folding and heat sealing the laminate pouch, the pouch can be degassed through the degassing port. After degassing, the degassing port can be sealed. In this way, unwanted gas can be removed from the system, thereby reducing the size of the protective housing. As a result, the simplicity of the battery cell system can be increased.

The invention will be further described in the following paragraphs. In one aspect, a first anode having a first anode tab, a second anode having a second anode tab transversely offset from the first anode tab, a first cathode having a first cathode tab, and a first cathode tab A battery cell system is provided that includes an electrode stack comprising a second cathode having a second cathode tab transversely offset therefrom.

In another aspect, a method for manufacturing a battery cell system is provided. The method includes forming a plurality of anodes having a plurality of anode tabs, wherein the plurality of anode tabs includes a first group of anode tabs transversely offset from a second group of anode tabs, and having a plurality of cathode tabs Forming a plurality of cathodes, wherein the plurality of cathode tabs includes a first group of cathode tabs transversely offset from a second group of cathode tabs, the first extension tab comprising a first group of anode tabs and an anode tab Welding to a second group of cathodes, and welding a second extension tab to the first group of cathode tabs and the second group of cathode tabs. In one example, a method includes attaching a first electrode tab support to a first group of anode tabs and a second group of anode tabs, and a second electrode tab support to a first group of cathode tabs and a second group of cathode tabs The method may further include attaching to the group. In another example, the method can further include placing the plurality of cathodes and anodes in at least one of the structural frame and the protective housing that at least partially surrounds the plurality of cathodes and anodes.

In another aspect, a plurality of first negative electrodes comprising first negative electrode tabs, a plurality of second negative electrodes including second negative electrode tabs-second negative electrode tabs are offset from the first negative electrode tabs An electrochemical cell is provided that includes a plurality of first positive electrodes comprising first positive electrode tabs and a plurality of second positive electrodes including second positive electrode tabs.

In another aspect, there is provided an electrochemical cell comprising a first positive electrode and a second positive electrode forming a positive electrode group, and a first negative electrode and a second negative electrode forming a negative electrode group, each electrode Is separated by a layer of silver porous separator material, each electrode has a tab width and offset so that the tabs of different electrodes do not overlap, at least two electrodes of the positive electrode group are welded together, and at least two of the negative electrode group The electrodes are welded together.

In another aspect, an inner frame is provided for an electrochemical cell comprising an electrode tab support, the electrode tab support comprising two slots for receiving the anode and cathode of the electrochemical cell, wherein the electrode tab support Prevents lateral movement of the anode and cathode.

In another aspect, an electrochemical cell is provided that includes a stack of aligned electrodes, the stack comprising at least four groups of electrode tabs offset from each other.

In any of the aspects or combinations of aspects, the electrode stack can further include a porous separator positioned between each of the first and second anodes and the first and second cathodes.

In any of the aspects or combinations of aspects, the battery cell system can further include a first extension tab welded to the first and second anode tabs and extending transversely between the first and second anode tabs. have.

In any of the aspects or combinations of aspects, the battery cell system can further include a second extension tab welded to the first and second cathode tabs and extending transversely between the first and second anode tabs. have.

In any of the aspects or combinations of aspects, the battery cell system can further include an electrode tab support, wherein the electrode tab support is provided with one or more of the first and second anodes and / or cathodes. It fits over the first and second extension tabs and provides a mechanical support for the first and second extension tabs.

In any of the aspects or combinations of aspects, the electrode tab support can include an electrically insulating polymer material, providing electrical isolation between the first and / or extension tabs and the protective housing.

In any of the aspects or combinations of aspects, the electrode tab support can include a first slit and a second slit for receiving the first and second extension tabs, wherein the first and second extension tabs These extend through the first and second slits in the electrode tab support.

In any of the aspects or combinations of aspects, the battery cell system can include a structural frame that at least partially surrounds the first and second anodes and the first and second cathodes.

In any of the aspects or combinations of aspects, the electrode tab support can be integrally formed within the protective housing, or is physically coupled directly to the protective housing.

In any of the aspects or combinations of aspects, the structural frame can be stretchable and include one or more walls bent inward toward the electrode stack, such that the one or more walls accommodate magnification during electrolyte activation.

In any of the aspects or combinations of aspects, the structural frame can include one or more faces having a reduced thickness recessed area paired with a thermal shim of the protective housing.

In any of the aspects or combinations of aspects, the battery cell system can further include a protective housing that includes a port that receives electrolyte and / or exhaust gases.

In any of the aspects or combinations of aspects, the negative electrodes and positive electrode tabs can be offset from each other.

In any of the aspects or combinations of aspects, the electrodes can be the same size, so that when stacked, the edges of the electrodes are aligned with each other, except for the tabs.

In any of the aspects or combinations of aspects, the tabs can be offset when the electrodes are stacked to form an array.

In any of the aspects or combinations of aspects, the electrochemical cell can further include a structural frame through which electrode tabs extend.

In any of the aspects or combinations of aspects, the structural frame limits the lateral movement of the electrode tabs.

In any of the aspects or combinations of aspects, the electrochemical cells can further include electrode extension tabs extending from the electrode tabs and welded to the electrode tabs.

In any of the aspects or combinations of aspects, at least four groups of electrode tabs can be welded to two electrode extension tabs, where each of the at least four groups of electrode tabs is one of the two electrode extension tabs Only one can be welded.

In any of the aspects or combinations of aspects, at least four groups of electrode tabs can include at least two groups of negative electrode tabs and at least two groups of positive electrode tabs.

In any of the aspects or combinations of aspects, at least four groups of electrode tabs can include a vertically folded portion welded to the extension tab.

In any of the aspects or combinations of aspects, the electrochemical cell can further include an injection molded frame.

In any of the aspects or combinations of aspects, the electrochemical cell can further include a multi-layered laminate pouch.

In any of the aspects or combinations of aspects, the electrochemical cell may further include a multi-use port for charging the electrochemical cell with electrolyte and / or degassing the electrochemical cell.

In any of the aspects or combinations of aspects, offset tabs of matching polarity can be welded to the electrode group tab, and then to the extension tab.

In any of the aspects or combinations of aspects, the anode tab can include nickel plated copper and the cathode tab can include aluminum.

In any of the aspects or combinations of aspects, the electrode tab support can have a triangular cross section.

The inventive subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various systems and configurations disclosed herein and other features, functions, and / or properties.

The following claims particularly point out certain combinations and subcombinations considered novel and non-obvious. These claims may refer to the "an" element or the "first" element or its equivalent. These claims should be understood to include incorporation of one or more of these elements, without requiring or excluding two or more of these elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed through amendments to the claims, or through the presentation of new claims in this or related applications. These claims are also considered to be included within the scope of the invention of the present disclosure, whether broader, narrower, identical, or different in scope to the original claims.

Claims (15)

As a battery cell system,
Electrode stack
Including, The electrode stack,
A first anode having a first anode tab;
A second anode having a second anode tab transversely offset from the first anode tab;
A first cathode having a first cathode tab; And
A second cathode having a second cathode tab transversely offset from the first cathode tab
Battery cell system comprising a. The battery cell system of claim 1, wherein the electrode stack further comprises a porous separator positioned between each of the first and second anodes and the first and second cathodes. The battery cell system of claim 1, further comprising a first extension tab welded to the first and second anode tabs and extending transversely between the first and second anode tabs. 4. The battery cell system of claim 3, further comprising a second extension tab welded to the first and second cathode tabs and extending transversely between the first and second cathode tabs. 5. The electrode tab support of claim 4, further comprising an electrode tab support, wherein the electrode tab support is fitted over one or more of the first and second anodes and / or cathodes and the first and second extension tabs. , A battery cell system providing a mechanical support for the first and second extension tabs. The battery cell system of claim 5, wherein the electrode tab support comprises an electrically insulating polymer material and provides electrical isolation between the first and / or extension tabs and the protective housing. 6. The electrode tab support of claim 5, wherein the electrode tab support includes first and second slits for receiving the first and second extension tabs, and the first and second extension tabs are the A battery cell system extending through the first slit and the second slit. The battery cell system according to claim 5, wherein the electrode tab support is integrally formed in a protective housing, or is physically coupled directly to the protective housing. The battery cell system of claim 1, further comprising a structural frame at least partially surrounding the first and second anodes and the first and second cathodes. 10. The battery cell of claim 9, wherein the structural frame comprises one or more walls that are flexible and bent inwards toward the electrode stack, wherein the one or more walls accommodate magnification during electrolyte activation. system. 10. The battery cell system of claim 9, wherein the structural frame comprises one or more faces having a reduced thickness recessed area mated with a heat seam of the protective housing. The battery cell system of claim 1, further comprising a protective housing comprising a port for receiving electrolyte and / or exhaust gases. A method for manufacturing a battery cell system,
Forming a plurality of anodes having a plurality of anode tabs, the plurality of anode tabs comprising a first group of anode tabs transversely offset from a second group of anode tabs;
Forming a plurality of cathodes having a plurality of cathode tabs, the plurality of cathode tabs comprising a first group of cathode tabs transversely offset from a second group of cathode tabs;
Welding a first extension tab to a first group of anode tabs and a second group of anode tabs; And
Welding a second extension tab to the first group of cathode tabs and the second group of cathode tabs;
How to include. 14. The method of claim 13, attaching a first electrode tab support to a first group of anode tabs and a second group of anode tabs, and a second electrode tab support to a first group of cathode tabs and to the cathode tab And attaching to the second group of people. 14. The method of claim 13, further comprising placing the plurality of cathodes and anodes in at least one of a structural frame and a protective housing that at least partially surrounds the plurality of cathodes and anodes.

Images