Arrangement for electrochemical cell

Abstract

The present invention provides an apparatus for homogenizing one or more regions within a plurality of electrochemical cells, the apparatus comprising a plurality of magnetic flux generators, each configured to generate a respective varying magnetic field through at least one of the plurality of electrochemical cells, the plurality of magnetic flux generators and the plurality of electrochemical cells are arranged in an alternating manner.

Description

Technical Field

[0001] The present invention relates to an apparatus for homogenizing one or more regions within a plurality of electrochemical cells. Background Technology

[0002] Electrochemical batteries are essential for many electrical systems, including portable devices such as mobile phones, laptops, and electric vehicles, as well as stationary devices and systems such as stationary home energy storage systems.

[0003] Electrochemical cells of various types and configurations can be selected based on size, shape, voltage, current, and other requirements. Examples of common cell shapes include pouch cells, prismatic cells, cylindrical cells, and button cells. Cells can also be connected in series or parallel to form cell units to provide the appropriate voltage and / or current for a specific application.

[0004] Typically, it is desirable for batteries to have large capacity and short charging time in order to increase the ratio of the time a device can operate independently of an external power source to the time it must be connected to an external power source for charging.

[0005] The performance and / or lifespan of electrochemical batteries are related to their structural quality. Specifically, heterogeneous structures (e.g., those resulting from heterogeneous layer deposition / removal during battery formation and / or operation) can impair battery performance and / or durability. Electrochemical batteries (such as lithium-ion batteries) typically have layered structures, including, for example, interfacial layers used to passivate the surfaces of electrochemically active interfaces within the battery. These layers are typically deposited / removed under electrochemical conditions during battery formation and / or operation. However, reliably controlling the homogeneity of the layer structure under these conditions can be challenging. It is known that the quality of the battery's layer structure significantly affects battery performance as well as the feasibility and economics of the electrochemical process. For example, in the context of lithium-ion batteries, the formation of interfacial layers must be reliably controlled during battery formation (i.e., during Formation Aging & Testing (FA&T)) and during battery operation to ensure safe and efficient battery operation.

[0006] Therefore, since the quality of the battery's internal structure significantly affects its performance and / or lifespan, it is crucial to reliably control the homogeneity of the battery's internal regions during battery formation and / or operation.

[0007] The present invention was designed based on the above considerations. Summary of the Invention

[0008] In a first aspect, the present invention provides an apparatus for homogenizing one or more regions within a plurality of electrochemical cells, the apparatus comprising:

[0009] Multiple magnetic flux generators are each configured to generate a corresponding changing magnetic field passing through at least one of the multiple electrochemical cells;

[0010] The plurality of magnetic flux generators and the plurality of electrochemical cells are arranged in an alternating manner.

[0011] Therefore, this device is configured to homogenize one or more regions within each of a plurality of electrochemical cells by ensuring that layer deposition / removal (during cell formation and / or operation) occurs under magneto-electrochemical conditions. This is achieved by providing a correspondingly varying magnetic field through (i.e., permeating) each cell. Advantageously, providing a varying magnetic field through the electrochemical cells increases the homogeneity of local resistance within the cells, thereby increasing the homogeneity of layers (e.g., solid electrolyte interface (SEI)) within the cells. Furthermore, performing layer deposition / removal under magneto-electrochemical conditions can also increase the rate of layer formation / removal. Thus, this device ensures that one or more regions within the plurality of cells can be homogenized during cell formation and / or cell operation, thereby improving cell performance, and optionally, layers can be formed / removed more rapidly.

[0012] Furthermore, the device can be configured to control the spatial and / or temporal relationships between the plurality of magnetic flux generators to prevent destructive interference from the plurality of correspondingly varying magnetic fields. The desired spatial and / or temporal relationships can be modeled using known computational techniques.

[0013] Optional features of the invention will be discussed below. The invention includes combinations of the described aspects and optional features, unless such combinations are obviously not permitted or explicitly stated to be avoided.

[0014] Each electrochemical cell can be a battery unit. Each electrochemical cell can be a positive-ion battery unit, and the current flow path can be the direction of positive ion propagation. Alternatively, each electrochemical cell can be a negative-ion battery unit, and the current flow path can be the direction of negative ion propagation. Each electrochemical cell can be a lithium-ion battery unit. Each electrochemical cell can be a solid-state battery unit.

[0015] Optionally, the varying magnetic field generated by at least one of the one or more flux generators may have a frequency of at least 0.1 Hz, or at least 1 Hz, or at least 5 Hz, or at least 10 Hz, or at least 20 Hz, or at least 50 Hz, or at least 75 Hz, or at least 100 Hz, or at least 125 Hz. Alternatively, or furthermore, the varying magnetic field generated by at least one of the one or more flux generators may have a frequency of 1000 Hz or lower, or 750 Hz or lower, 500 Hz or lower, or 250 Hz or lower, or 150 Hz or lower, or 100 Hz or lower.

[0016] Optionally, the device may include one or more battery stations, each configured to accommodate a corresponding plurality of said electrochemical cells. Each battery station may include a battery tray and / or a battery container to support the corresponding plurality of electrochemical cells. For example, the / each battery tray / container may be made of a magnetically sensitive material to direct magnetic fields to preferred locations, such as confining and separating the magnetic field to the / each battery tray / container, to maximize control over the field structure and minimize stray magnetic field loss to the local environment.

[0017] Optionally, the plurality of magnetic flux generators may be arranged within each battery station, such that each battery station includes at least one of the plurality of magnetic flux generators. When the magnetic flux generators are arranged within each battery station and each battery station includes a corresponding battery tray and / or battery container, the magnetic flux generators may also be supported by the corresponding battery tray and / or battery container.

[0018] Optionally, each battery station may include at least as many magnetic flux generators as electrochemical cells. Optionally, the magnetic flux generators and electrochemical cells in each battery station may be arranged alternately. For example, the magnetic flux generators and electrochemical cells in each battery station may be arranged such that each cell is sandwiched between a pair of corresponding magnetic flux generators, or vice versa. Conveniently, this ensures that the electrochemical cells within each battery station are uniformly permeated by a correspondingly varying magnetic field.

[0019] Optionally, the one or more battery stations can be multiple battery stations. The battery stations can be arranged in a grid / array configuration and / or stacked to align them vertically. Conveniently, this allows the battery stations to be deployed (e.g., erected as towers) in larger-scale battery manufacturing facilities (e.g., superfactories) and / or in stationary home energy storage systems to simultaneously expose a large number of electrochemical batteries to varying magnetic fields, thereby achieving the beneficial effects of the invention.

[0020] Optionally, the plurality of magnetic flux generators may be interspersed among the plurality of battery stations. Optionally, the magnetic flux generators and the battery stations may be arranged such that each battery station is sandwiched between a corresponding pair of the plurality of magnetic flux generators. Conveniently, this ensures that the electrochemical cells within each battery station are uniformly permeated by the correspondingly varying magnetic field.

[0021] Optionally, the plurality of battery stations may be housed within a container having one or more walls, and at least one of the plurality of magnetic flux generators may be arranged outside the container and adjacent to a corresponding one of the one or more walls of the container. For example, each magnetic flux generator may be adjacent to a corresponding wall of the container, or each magnetic flux generator may be adjacent to a corresponding wall of the container, extending along a plane substantially parallel to the container wall and spaced apart from the container wall by a small gap.

[0022] Optionally, the device may include at least one power source configured to supply power to the plurality of electrochemical cells. When the device includes multiple battery stations, the at least one power source may be multiple power sources, each configured to supply power to the electrochemical cells of a corresponding one of the multiple battery stations. This configuration ensures that the power requirements of different battery stations are independent of each other, thereby improving the controllability of the process of homogenizing one or more regions within the plurality of electrochemical cells.

[0023] Optionally, the at least one power source may be further configured to power the plurality of magnetic flux generators.

[0024] Optionally, each magnetic flux generator can be connected to a shared or corresponding power supply device to receive power from it, wherein the shared or corresponding power supply device is different from the at least one power source. Providing each magnetic flux generator with a shared or corresponding power supply device different from the at least one power source conveniently ensures that the power demand of the electrochemical cell is independent of the power demand of the magnetic flux generator. This can improve the controllability of the generated changing magnetic field.

[0025] Optionally, when each flux generator is connected to the shared power supply, a subset of the plurality of flux generators may each be connected to the shared power supply via a corresponding shared electrical connection.

[0026] Optionally, each varying magnetic field can be one of the following or any combination thereof: rotation, pulse, and / or oscillation. Rotation of each varying magnetic field can be around an axis having a component perpendicular to the direction of the corresponding varying magnetic field. Rotation of each varying magnetic field can be around an axis having a component parallel to the direction of the corresponding varying magnetic field. Rotation of each varying magnetic field can be around an axis having a component perpendicular to the direction of the current within each electrochemical cell. Rotation of each varying magnetic field can be around an axis having a component parallel to the direction of the current within each electrochemical cell. Each rotating magnetic field can be provided by a rotating permanent magnet, or a temporary magnet, or an electromagnet, or can be provided by an array of electromagnets in which the electromagnets are sequentially activated to effectively rotate the corresponding magnetic field.

[0027] Optionally, each varying magnetic field can be controllably varied in one, two, or three spatial dimensions. Furthermore, or alternatively, the polarity and / or magnitude of each magnetic field can be controllably varied.

[0028] Optionally, each magnetic flux generator may include one or more magnetic field sources.

[0029] Optionally, at least one of the one or more magnetic field sources may include a permanent magnet and a corresponding mechanism for moving the permanent magnet and / or one or more of the electrochemical cells. For example, the mechanism may be an electric motor. Typically, when a changing magnetic field is generated by moving the permanent magnet, it can be varied by changing the direction and / or speed at which the permanent magnet is moved by the corresponding mechanism. To completely “turn off” the transient nature of the permanent magnet, it must be kept stationary. When the device includes a controller as described below, the controller may be configured to control the mechanism (e.g., the electric motor) to control the characteristics (e.g., frequency and / or direction) of the changing magnetic field generated by the flux generator.

[0030] Optionally, at least one of the one or more magnetic field sources can be an electromagnet. The electromagnet can be of any type. The electromagnet typically comprises a coil wound around a core wire. The core can be made of a high-permeability magnetic material. The core can be a metallic core (e.g., a ferromagnetic core). Alternatively, the core can be an air-filled space at the center of the electromagnet, i.e., an air core. Each electromagnet can be coupled to a shared or corresponding power supply device as described above. The magnetic field generated by each electromagnet can be varied by changing the magnitude and / or direction of the power supplied by the power supply device. For example, it may be necessary to turn off one or more electromagnets (i.e., not supplying them with power) to change the varying magnetic field generated by the corresponding flux generator. Furthermore or alternatively, it may be necessary to supply currents with different directions and / or amplitudes to the respective different electromagnets, for example, to change the magnetic polarity of the corresponding generated magnetic field.

[0031] When the device includes a controller as described below, the controller can be configured to control the current supplied to the flux generator to control the characteristics of the resulting changing magnetic field. In some examples, the controller can be configured to control the magnitude and / or direction and / or frequency of the power supplied by the / each power supply device to the one or more flux generators, and / or to shut off the power supply to selected one or more of the flux generators. In some examples, the controller can be configured to cause the / each power supply device to supply currents with different directions and / or amplitudes and / or frequencies to selected one or more of the flux generators (in this case, electromagnets).

[0032] Optionally, each electromagnet may be an air-core electromagnet, extending longitudinally (i.e., axially) and radially to define a space for accommodating a corresponding electrochemical cell among the plurality of electrochemical cells. The electrochemical cell may be cylindrical. Here, an air-core electromagnet refers to a coil (i.e., a solenoid) that includes a central air-filled space defined by the coil and does not include a solid core, such as a ferromagnetic core. When the one or more magnetic field sources are multiple magnetic field sources, each flux generator can be provided by stacking the plurality of air-core electromagnets to provide a shared air core shared by all air-core electromagnets. The air core / shared air core can accommodate a corresponding electrochemical cell, such as a cylindrical cell.

[0033] At least one of the plurality of magnetic flux generators may be a bent magnetic flux generator. Each bent magnetic flux generator may be bent to at least partially surround one of the plurality of electrochemical cells. That is, the shape and size of each bent magnetic flux generator may be designed to bend at least partially around a bent portion of the electrochemical cell (e.g., a cylindrical cell). For example, each bent magnetic flux generator may include at least one bent portion (i.e., a bend, the shape and size of which are designed to bend around a bent portion of the electrochemical cell) and optionally at least one planar (flat) portion.

[0034] When each bending magnetic flux generator includes multiple magnetic field sources, the multiple magnetic field sources can be arranged around a curve, arc, circle, or polygon to provide the bending portion of the bending magnetic flux generator. The curve, arc, circle, or polygon can be provided by bending, semi-circular, circular, or polygonal mechanical supports, respectively.

[0035] Alternatively, when each magnetic flux generator includes multiple magnetic field sources, these sources can be arranged in a common plane. A magnetic flux generator comprising multiple magnetic field sources arranged in a common plane is called a planar (flat) magnetic flux generator. A planar magnetic flux generator can be provided by a single magnetic field source, which is a planar permanent magnet.

[0036] At least some of the plurality of magnetic flux generators may be planar magnetic flux generators. When the device includes one or more battery stations, at least some of the magnetic flux generators may be disposed outside the one or more battery stations (e.g., outside the one or more battery containers). Alternatively, at least some magnetic flux generators may be disposed inside the one or more battery stations, as discussed in more detail above. Conveniently, when some magnetic flux generators are disposed outside the one or more battery stations and some are disposed inside the one or more battery stations, it can be ensured that the one or more battery stations are uniformly permeated by the generated changing magnetic field.

[0037] In some examples, the device includes one or more battery stations as described above, one or more planar magnetic flux generators located outside the one or more battery stations, and one or more magnetic flux generators disposed inside the one or more battery stations. For example, when each / every battery station includes a battery container, each / every planar magnetic flux generator may be adjacent to a corresponding wall of the battery container, or each / every planar magnetic flux generator may be adjacent to a corresponding wall of the battery container such that it extends along a plane substantially parallel to and slightly spaced from the wall of the battery container. Each / every magnetic flux generator disposed inside the battery station may include, for example, a single electromagnet.

[0038] As described above, the device may further include a controller configured to control the varying magnetic fields generated by the plurality of magnetic flux generators. For example, the controller may be configured to control (e.g., vary over time) the direction and / or magnitude and / or frequency of the generated varying magnetic fields. The controller may be configured to control each varying magnetic field (e.g., by selecting values ​​for one or more three-dimensional spatial dimensions, and / or magnitude, and / or phase, and / or amplitude, and / or frequency of the varying magnetic field) based on any one or any combination of electrical, magnetic, optical, and / or acoustic measurements performed on one or more electrochemical cells. The electrical, magnetic, optical, and / or acoustic measurements may be performed while each varying magnetic field is individually and controllably varied. The device may include a sensor unit configured to perform electrical, magnetic, optical, and / or acoustic measurements. For example, the sensor unit may include any one or any combination of Hall, Gaussian, optical, and / or acoustic sensors. The controller may be communicatively connected to the sensor unit.

[0039] Optionally, the controller can be configured to:

[0040] At each change in the plurality of changing magnetic fields, the electrochemical overpotential of each of the plurality of electrochemical cells is monitored; and

[0041] The optimal value is selected for each varying magnetic field to minimize each electrochemical overpotential.

[0042] The monitoring can be discrete or continuous. Furthermore, the controller can select an optimal value for any one or any combination of the polarity, magnitude, phase, amplitude, and / or frequency of each varying magnetic field to minimize the electrochemical overpotential. The controller can repeatedly monitor each electrochemical overpotential and select the optimal value as needed to minimize each electrochemical overpotential.

[0043] The controller can be configured to monitor each electrochemical overpotential via direct overpotential measurement. Direct overpotential measurement can be performed, for example, using electrochemical impedance spectroscopy (impedance measurement at multiple frequencies (spectroscopy) or a fixed frequency). Alternatively, the amplitude, phase shift, and frequency of the electrochemical potential or current of the / each cell, or any combination thereof, can be measured to monitor the electrochemical overpotential.

[0044] The controller can be configured to monitor each electrochemical overpotential using any one or any combination of electrical, magnetic, optical, and acoustic measurements performed on the plurality of electrochemical cells. For example, such measurements can be used as alternative indicators to determine the electrochemical overpotential of each electrochemical cell. The controller can be electrically connected to each of the magnetic flux generators and each of the electrochemical cells.

[0045] When the controller is configured to monitor each electrochemical overpotential using any one or any combination of electrical, magnetic, optical, and acoustic measurements performed on the plurality of electrochemical cells, the controller may be electrically connected to each magnetic flux generator and each electrochemical cell, and additionally communicatively connected to sensor units configured to perform electrical, magnetic, optical, and / or acoustic measurements. For example, the sensor units may include any one or any combination of Hall, Gaussian, optical, and / or acoustic sensors. This is because electrical, magnetic, optical, and acoustic measurements can indicate the state of charge / health of the electrochemical cells. For example, optical sensors may be configured to measure deformation and / or material buildup / loss at selected locations on the electrochemical cell. Acoustic sensors may be configured to measure the decibel response to acoustic signals emitted to / reflected from one or more selected locations on / from the electrochemical cell. Conveniently, the decibel response is correlated with the state of charge at the selected locations on the electrochemical cell.

[0046] In a second aspect, the present invention provides a method for homogenizing one or more regions within a plurality of electrochemical cells, the method comprising the steps of:

[0047] Multiple magnetic flux generators are available;

[0048] The plurality of magnetic flux generators and the plurality of electrochemical cells are arranged in an alternating manner; and

[0049] A corresponding changing magnetic field is generated through one or more of the magnetic flux generators, passing through at least one of the plurality of electrochemical cells.

[0050] In a third aspect, the present invention provides an apparatus for homogenizing one or more regions within a plurality of electrochemical cells, the apparatus comprising:

[0051] Multiple magnetic flux generators are each configured to generate a corresponding magnetic field passing through at least one of the multiple electrochemical cells;

[0052] The plurality of magnetic flux generators and the plurality of electrochemical cells are arranged in an alternating manner. Attached Figure Description

[0053] The embodiments and experiments illustrating the principles of the present invention will now be discussed with reference to the accompanying drawings, wherein:

[0054] Figures 1A to 1D schematically illustrate battery stations comprising multiple electrochemical cells arranged accordingly in containers or trays;

[0055] Figure 2 shows a variant of the battery station that includes multiple electrochemical cells and multiple magnetic flux generators;

[0056] Figure 3 shows a variant of the battery station that includes multiple electrochemical cells and multiple magnetic flux generators;

[0057] Figure 4 shows a variant of the battery station that includes multiple electrochemical cells and multiple magnetic flux generators;

[0058] Figure 5 shows a variant of the battery station that includes multiple electrochemical cells and multiple magnetic flux generators;

[0059] Figure 6 shows a variant of the battery station that includes multiple electrochemical cells and multiple magnetic flux generators;

[0060] Figure 7 shows a variant of the battery station that includes multiple electrochemical cells and multiple magnetic flux generators;

[0061] Figure 8A shows multiple battery stations from Figure 2 arranged in a tower-like configuration;

[0062] Figure 8B shows several towers of the type shown in Figure 8A;

[0063] Figure 9A shows multiple battery stations as shown in Figure 3 arranged in a tower-like configuration;

[0064] Figure 9B shows several towers of the type shown in Figure 9A;

[0065] Figure 10A shows multiple battery stations as shown in Figure 5 arranged in a tower-like configuration;

[0066] Figure 10B shows several towers of the type shown in Figure 10A;

[0067] Figure 11 shows a container comprising multiple battery stations interspersed among multiple magnetic flux generators;

[0068] Figure 12 shows a partial view of the container in Figure 11;

[0069] Figure 13 shows a container comprising multiple battery stations interspersed among multiple magnetic flux generators;

[0070] Figure 14 shows a partial view of the container in Figure 13;

[0071] Figures 15A to 15B show corresponding variations of the container, including multiple battery stations sandwiched in the middle by a pair of magnetic flux generators;

[0072] Figures 16A to 16B schematically illustrate corresponding variant configurations of an electrochemical cell connected to a power source and a magnetic flux generator connected to a power supply device;

[0073] Figure 17A schematically illustrates an apparatus for homogenizing one or more regions within multiple electrochemical cells, while Figure 17B shows a partial exploded view of the apparatus in Figure 17A.

[0074] Figure 18A schematically illustrates an apparatus for homogenizing one or more regions within multiple electrochemical cells, while Figure 18B shows a partial exploded view of the apparatus in Figure 18A.

[0075] Figure 19 schematically shows an electrochemical cell connected to a circuit;

[0076] Figures 20A to 20B show the current collector and electrode of the electrochemical cell in Figure 19 before and after the deposition of the interface layer, respectively.

[0077] Figures 21A to 21B schematically illustrate the state of the electrode particles in Figures 20A to 20B before and after the deposition of the interface layer;

[0078] Figure 22 schematically illustrates a variant of an electrochemical cell connected to a circuit;

[0079] Figures 23A to 23B show the current collector and electrode of the electrochemical cell in Figure 22 before and after the deposition of the interface layer, respectively;

[0080] Figure 24 schematically illustrates a variant of an electrochemical cell connected to a circuit;

[0081] Figures 25A to 25B show the current collector and electrode of the electrochemical cell in Figure 24 before and after the deposition of the interface layer, respectively.

[0082] Figure 26 schematically illustrates a configuration including an electrochemical cell and a magnetic flux generator;

[0083] Figures 27A and 27B schematically illustrate the current collector and electrode of the electrochemical cell in Figure 26 before and after the deposition of the interface layer, respectively.

[0084] Figures 28A to 28B schematically illustrate the state of the electrode particles in Figures 27A to 27B before and after the deposition of the interface layer;

[0085] Figure 29 schematically illustrates a configuration including an electrochemical cell and a magnetic flux generator;

[0086] Figures 30A to 30B schematically show the current collector and electrode of the electrochemical cell in Figure 29 before and after the deposition of the interface layer, respectively.

[0087] Figure 31 schematically illustrates a configuration including an electrochemical cell and a magnetic flux generator; and

[0088] Figures 32A and 32B schematically illustrate the states of the current collector and electrode of the electrochemical cell in Figure 31 before and after the deposition of the interface layer. Detailed Implementation

[0089] Various aspects and embodiments of the invention will now be discussed with reference to the accompanying drawings. Other aspects and embodiments will be apparent to those skilled in the art. In particular, those skilled in the art will recognize that other orientations of the features shown in the figures are possible. These figures are schematic and not necessarily drawn to scale.

[0090] According to the present invention, an apparatus for homogenizing one or more regions within a plurality of electrochemical cells is provided. The apparatus includes a plurality of magnetic flux generators, each configured to generate a corresponding magnetic field (e.g., a varying magnetic field) passing through at least one of the plurality of electrochemical cells, wherein the plurality of magnetic flux generators and the plurality of electrochemical cells are arranged in an alternating manner.

[0091] Typically, the device can be used to homogenize one or more regions within multiple electrochemical cells and enhance battery performance during cell formation (e.g., during FA&T) and / or during battery operation. Specifically, when used during cell formation, the device can be used to form a large number of electrochemical cells under magneto-electrochemical conditions in the context of large manufacturing facilities such as Gigafactories. When used during battery operation, the device can be used to enhance the performance of large stationary equipment / systems such as stationary home energy storage systems.

[0092] Regardless of its application, different configurations of device 100 are possible. These examples will be discussed below with reference to Figures 1 to 17.

[0093] First, the device 100 may include one or more battery stations 12, each configured to accommodate a corresponding plurality of electrochemical cells 20. Examples of such battery stations 12 are shown in Figures 1A to 1D. Specifically, Figures 1A and 1B show a plurality of electrochemical cells 20 housed within a battery container 15, while Figures 1C and 1D show a plurality of electrochemical cells housed within a battery tray 14. For example, each battery tray / battery container may be made of one or more magnetically sensitive materials to guide the field structure, such as directing a magnetic field to a preferred location, or confining and separating the field to each battery tray / battery container, to maximize control over the field structure and minimize stray magnetic field loss to the local environment.

[0094] For example, the plurality of magnetic flux generators 10 of device 100 may be arranged inside each battery station 12 such that each battery station includes at least one of the plurality of magnetic flux generators 10. Specifically, Figure 2 shows a battery station 12 that includes a battery container 15 that surrounds a single planar magnetic flux generator 10, which supports a plurality of cylindrical electrochemical cells 20 placed upright thereon.

[0095] In the examples of Figures 3 through 7, each battery station 12 includes a corresponding battery container 15 that surrounds at least the same number of magnetic flux generators 10 as the number of electrochemical cells 20. In some of these arrangements, each cell 20 is sandwiched between a corresponding pair of magnetic flux generators 10. For example, in Figure 3, the electrochemical cells 20 are pouch cells, which are arranged alternately with multiple planar (flat) magnetic flux generators 10 inside the battery container 15. In a variant of Figure 4, the magnetic flux generators 10 are extending slats that extend along the corresponding top and bottom edges of each pouch cell 20. The top edge of the pouch cell is the edge containing its tabs, and the bottom edge is opposite the top edge. Each pouch cell 20 is sandwiched between a corresponding pair of magnetic flux generators located at its top and bottom edges, respectively. This configuration can be modified. For example, elongated magnetic flux generators 10 may extend substantially vertically or at acute / obtuse angles to the top / bottom edges of the pouch cell.

[0096] Further examples of arrangements of the cylindrical electrochemical cells 20 are discussed with reference to Figures 5 through 7. In the example of Figure 5, each cell station 12 includes a mechanical support 51 supporting a plurality of upright magnetic flux generators 10, each of which is an air-core electromagnet and extends longitudinally (i.e., axially) and radially to define a space for accommodating the respective cylindrical electrochemical cell 20. Here, an air-core electromagnet means a coil (i.e., a solenoid) that includes a central air-filled space defined by the coil and does not include a solid core, such as a ferromagnetic core. In this arrangement, the air-core electromagnets are upright supported on the base plate of the cell container 15 and each surrounds the respective cylindrical cell 20.

[0097] In the alternative arrangement of Figure 6, the cylindrical cells 20 are similarly arranged in a grid, but each flux generator 10 is a planar flux generator. The flux generators 10 are arranged such that each row of electrochemical cells 20 is laterally sandwiched between a pair of corresponding upright flux generators 10, which extend parallel to the corresponding sidewalls of the battery container 15.

[0098] Finally, in the arrangement of Figure 7, each flux generator 10 is a disk-shaped flux generator. Cylindrical cells 20 are arranged vertically within the cell container 15 in a grid pattern. Each cylindrical cell has a bottom wall, a top wall, and side walls extending therebetween. A corresponding flux generator 10 is provided on or adjacent to the bottom and top walls of each cylindrical cell, such that each cell is longitudinally (vertically) sandwiched between a pair of corresponding disk-shaped flux generators 10. The area of ​​each flux generator 10 may be equal to or substantially equal to the area of ​​the wall it provides or is adjacent to (i.e., the top or bottom wall).

[0099] The battery station 12, of the type discussed with reference to Figures 2 through 7, can be arranged in a grid / array and / or stacked so that it is vertically aligned. Conveniently, this allows the battery station 12 to be mounted in a tower 17, as shown in Figures 8A through 10B, for example, for use in large battery manufacturing facilities or stationary home energy storage systems.

[0100] Specifically, Figures 8A, 9A, and 10A show the battery stations of Figures 2, 3, and 5 arranged on rack 27 and stacked vertically in tower 17, respectively. In large-scale battery manufacturing facilities or stationary home energy storage systems, multiple towers 17 may be arranged side by side (as shown in Figures 8B, 9B, and 10B) and / or vertically.

[0101] Next, when the device 100 includes a plurality of battery stations 12, these battery stations can be housed (enclosed) within a container 40. This will be discussed with reference to Figures 11, 13, 15A, and 15B. In the examples of Figures 11 and 12, the container 40 includes a plurality of battery stations 12 (only one is shown) and a plurality of planar flux generators 10. The battery stations 12 and flux generators 10 within the container are arranged in an alternating manner. In the example of Figure 11, the flux generators 10 extend vertically (i.e., parallel to the sidewalls of the container), such that each battery station 12 is laterally sandwiched between a pair of corresponding flux generators 10. This is also shown in Figure 12, which is a partial view of the container 40 of Figure 11. In the example of Figure 13, the flux generators 10 extend parallel to the top and bottom walls of the container, such that each battery station 12 is vertically sandwiched between a pair of corresponding flux generators 10. This is also shown in Figure 14, which is a partial view of the container 40 of Figure 13.

[0102] Alternatively, at least one of the plurality of flux generators 10 can be arranged outside the container 40 and adjacent to its wall. Two such example configurations are discussed with reference to Figures 15A and 15B. In Figure 15A, the container 40 is laterally sandwiched between a pair of vertically extending flux generators 10 parallel to the respective sidewalls of the container. In the example of Figure 15B, the container 40 is vertically sandwiched between a pair of flux generators 10 parallel to the respective top and bottom walls of the container.

[0103] The device 100 may include at least one power source 1 configured to supply power to the plurality of electrochemical cells 20. For example, the power source 1 may be electrically connected to each electrochemical cell 20 via circuit 24 to supply power thereto, as schematically shown in Figures 16A and 16B. The simplified electrochemical cell 20 shown in Figures 16A and 16B includes a pair of current collectors 22 (each current collector having an active material coating on its inner side to provide a corresponding electrode 21), an electrolyte (not shown) provided between the electrodes, and a separator 25 containing the electrolyte between the electrodes. Preferably, the active material coating is applied to the corresponding inner sides of the two current collectors. Typically, the active material coating may be single-sided (e.g., coating only the inner side of the corresponding current collector) or double-sided (i.e., coating both the inner and outer sides of the corresponding current collector). However, for visual simplicity, a single-sided active material coating is shown in Figures 16A, 16B, 19, 22, 26, and 29. Each magnetic flux generator 10 may be connected via circuit 24' to a shared or corresponding power supply device 2 to receive power therefrom. The power supply device 2 is different from the power source 1.

[0104] In the example of Figure 15A, the magnetic flux generator 10 includes a permanent magnet 10' and a mechanism 26 for moving the permanent magnet to generate a changing magnetic field. Mechanism 26 may be, for example, an electric motor connected to the power supply device 2 via circuit 24'. In the example of Figure 15B, the magnetic flux generator 10 includes an electromagnet, which itself is connected to the power supply device 2 via circuit 24' to generate its corresponding (e.g., alternating) magnetic field. The electromagnet can be of any type. The electromagnet typically comprises a coil wound around a core wire. For example, the core may be a metal core (e.g., a ferromagnetic core) or it may be an air-filled space at the center of the electromagnet, i.e., an air core. The magnetic field generated by the electromagnet can be varied / controlled by changing the magnitude and / or direction of the power supplied by the power supply device.

[0105] Referring to Figures 17A and 18A, an example configuration of device 100 is discussed, comprising a plurality of battery stations 12 and a plurality of magnetic flux generators 10, wherein the electrochemical cells are electrically connected to a power source 1, and the magnetic flux generators are electrically connected to a shared power supply 2. In both figures, one of the battery stations 12 is shown to house a plurality of electrochemical cells 20 and a plurality of magnetic flux generators 10, and the plurality of battery stations 12 are arranged in a grid. The magnetic flux generators 10 of all battery stations 12 are electrically connected to a shared power supply 2, which is different from the power source 1. In the example of Figures 17A and 18A, the magnetic flux generators 10 of each row of battery stations 12 are connected to the shared power supply 2 via a corresponding shared electrical connection as part of circuit 24'. The electrochemical cells 20 shown in Figures 17A and 18A are each connected to the power source 1, as shown in more detail in the exploded views of Figures 17B and 18B, respectively. In Figure 17A, the batteries 20 and magnetic flux generators 10 in each battery station 12 are arranged as shown in Figure 3, while those shown in Figure 18A are arranged as shown in Figure 6. However, the devices 100 of Figures 17A and 18A can also be configured such that the electrochemical batteries 20 and magnetic flux generators 10 are arranged in the battery station according to any of the battery station arrangements in Figures 2, 4, 5, and 7.

[0106] Next, the beneficial effects of the invention will be discussed with reference to Figures 18 to 32B. Specifically, Figures 19, 22, and 24 show example configurations of electrochemical cells 20 connected to a power source 1 via circuit 24, for example during cell formation (e.g., during the FA&T phase) or during cell operation. Thus, in these configurations, layers (e.g., interface layers) are formed under electrochemical conditions.

[0107] Figure 19 shows the same electrochemical cell 20 as Figures 16A and 16B. Figures 22 and 24 show corresponding variations of the electrochemical cell 20 in Figure 1. The electrochemical cell cell of Figure 22 includes a pair of current collectors 22, 22', wherein only one current collector 22' contains an active material coating that provides an electrode 21. The active material coatings providing the electrode 22 in Figure 19 and the corresponding active material coatings providing the electrode 22' in Figure 22 each have a textured surface. The textured surface of the active coating is provided by a plurality of spaced electrode particles. In the example of Figure 19, the electrode particles are substantially spherical, while in the example of Figure 22, the electrode particles are substantially rectangular, extending from the current collector to form a columnar electrode structure. The electrochemical cell 20 of Figure 24 includes only a pair of planar (flat) current collectors 22, which serve as electrodes but do not contain any active material coating. Typically, electrodes can be provided by ordinary current collectors (i.e., without any active material coating), single or multi-layer stacked active material coatings, or by filling with active (electrode) material.

[0108] During battery formation and / or operation under electrochemical conditions, a corresponding layer (e.g., an interface layer) 23 is formed on electrode 21. For example, interface layer 23 may be part of a solid electrolyte interface (SEI). The formation of interface layer 23 in the battery 20 of the examples in Figures 19, 22, and 24 is shown in Figures 20A and 20B, 23A and 23B, and 25A and 25B, respectively. Specifically, Figures 20A, 23A, and 25A show corresponding partial exploded views of the battery 20 in Figures 19, 22, and 24, including the state of its electrode 21 before interface layer formation. As previously mentioned, reliably controlling layer formation under electrochemical conditions can be challenging. Therefore, the interface layer 23 formed under these conditions often has a heterogeneous structure, which may negatively impact the performance of the electrochemical battery 20.

[0109] The formed interface layer 23 is shown in Figures 20B, 23B, and 25B, respectively. As can be seen from these figures, the corresponding interface layer 23 lacks homogeneity and is not uniformly distributed on the electrode 21. This is also illustrated by Figures 21A and 21B, where Figure 21A shows a partial exploded view of the electrode (i.e., a single electrode particle) of Figure 20A before the formation of the interface layer 23, and Figure 21B shows the electrode particle of Figure 21A partially covered by the heterogeneous interface layer 23.

[0110] The lack of homogeneity in interface layer 23 is one example of the technical challenge addressed by this invention.

[0111] This invention is based on the observation that providing a magnetic field through an electrochemical cell under electrochemical conditions (during cell formation and / or cell operation) significantly improves the homogeneity of the formed layer, thereby improving the homogeneity of one or more regions of the cell, and consequently improving the performance and / or durability of the cell.

[0112] This concept is illustrated in Figures 26 to 32B. Specifically, Figures 26, 29, and 31 respectively show the electrochemical cells 20 of Figures 19, 22, and 24 connected to the power source 1 via circuit 24. Furthermore, a magnetic flux generator 10 configured to generate a magnetic field (e.g., a changing magnetic field) through the electrochemical cell 20 is also shown. Therefore, by providing a magnetic field through the cell, the cells in Figures 26, 29, and 31 are under magneto-electrochemical conditions. This improves the homogeneity of the deposited interface layer 23, as shown in Figures 27A, 27B, 28A, 28B, 30A, 30B, 32A, and 32B, in contrast to Figures 20A, 20B, 21A, 21B, 23A, 23B, 25A, and 25B, respectively.

[0113] Modifications to device 100 are possible. Each magnetic field generated by each flux generator 10 can be a static magnetic field or a varying magnetic field. Each varying magnetic field can be one of the following or any combination thereof: rotation, pulse, and / or oscillation. Rotation of each varying magnetic field can be around an axis having a component perpendicular to the direction of the corresponding varying magnetic field. Rotation of each varying magnetic field can be around an axis having a component parallel to the direction of the corresponding varying magnetic field. Rotation of each varying magnetic field can be around an axis having a component perpendicular to the direction of the current within the / each electrochemical cell. Rotation of each varying magnetic field can be around an axis having a component parallel to the direction of the current within the / each electrochemical cell. Each rotating magnetic field can be provided by rotating one or more of the electrochemical cells, by rotating a permanent magnet or temporary magnet or electromagnet, or by an array of electromagnets in which the electromagnets are sequentially activated to effectively rotate the corresponding magnetic field.

[0114] Each changing magnetic field can be controllably varied in one, two, and / or three spatial dimensions. Additionally or alternatively, the polarity and / or magnitude of each magnetic field can be controllably varied.

[0115] Each magnetic flux generator may include one or more magnetic field sources. The one or more magnetic field sources may be multiple magnetic field sources. The multiple magnetic field sources may be arranged in a common plane. At least one of the one or more magnetic field sources may include a permanent magnet and a corresponding mechanism (e.g., an electric motor) for moving the permanent magnet and / or one or more electrochemical cells. At least one of the one or more magnetic field sources may be an electromagnet.

[0116] Device 100, as shown, for example, in Figures 17A and 18A, may be adapted to further include a controller (not shown) configured to: monitor the electrochemical overpotential of each of the one or more electrochemical cells 20 as each magnetic field change occurs in the one or more varying magnetic fields; and select an optimal value for each varying magnetic field to minimize each electrochemical overpotential. The monitoring may be discrete or continuous. Furthermore, the controller may select an optimal value for any one or any combination of the polarity, magnitude, phase, amplitude, and / or frequency of each varying magnetic field to minimize the electrochemical overpotential. The controller may repeat monitoring of each electrochemical overpotential and selection of the optimal value as needed to minimize each electrochemical overpotential multiple times.

[0117] The controller can be configured to monitor each electrochemical overpotential via direct overpotential measurement. Direct overpotential measurement can be performed, for example, using electrochemical impedance spectroscopy (impedance measurement at multiple frequencies or a fixed frequency). Alternatively, the amplitude, phase shift, and frequency of the electrochemical potential or current of the / each cell, or any combination thereof, can be measured to monitor the electrochemical overpotential.

[0118] The controller can be configured to monitor each electrochemical overpotential using any one or any combination of electrical, magnetic, optical, and acoustic measurements performed on the one or more electrochemical cells. For example, such measurements can be used as alternative indicators to determine the electrochemical overpotential of each electrochemical cell. The controller can be electrically connected to each of the one or more magnetic flux generators and each of the one or more electrochemical cells.

[0119] When the controller is configured to monitor each electrochemical overpotential using any one or any combination of electrical, magnetic, optical, and acoustic measurements performed on the one or more electrochemical cells, the controller may be electrically connected to each magnetic flux generator and each electrochemical cell, and additionally communicatively connected to a sensor unit (not shown) configured to perform electrical, magnetic, optical, and / or acoustic measurements. For example, the sensor unit may include any one or any combination of Hall, Gaussian, optical, and / or acoustic sensors. This is because electrical, magnetic, optical, and acoustic measurements can indicate the state of charge / health of the electrochemical cells. For example, an optical sensor may be configured to measure deformation and / or material buildup / loss at selected locations on the one or more electrochemical cells. An acoustic sensor may be configured to measure the decibel response to acoustic signals emitted to / reflected from one or more selected locations on the one or more electrochemical cells. An example sensor configuration is shown in Figure 11 of GB application 2301222.2, the subject matter of which is incorporated herein by reference.

[0120] Features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their particular form or according to the means for performing the disclosed functions, or the methods or processes for obtaining the disclosed results, may, where appropriate, be used alone or in any combination of these features to implement the invention in different forms.

[0121] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when this disclosure is given. Therefore, the exemplary embodiments of the invention described above are to be considered illustrative rather than restrictive. Various changes may be made to the described embodiments without departing from the spirit and scope of the invention.

[0122] To avoid any ambiguity, any theoretical explanations provided herein are intended to improve the reader's understanding. The inventor does not wish to be bound by any of these theoretical explanations.

[0123] Any chapter headings used in this article are for organizational purposes only and should not be construed as limiting the topics described.

[0124] Throughout this specification, including the following claims, unless the context otherwise requires, the words “comprising” and “including”, as well as variations such as “comprising,” “including,” and “including”, shall be understood to imply inclusion of the said whole or step or group of whole or steps, but not to exclude any other whole or step or other group of whole or steps.

[0125] It is important to note that, as used in the specification and appended claims, the singular forms “a,” “an,” and “the” include plural objects unless the context explicitly specifies otherwise. A range herein may be expressed as from “about” a particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from one particular value and / or to another particular value. Similarly, when a value is expressed as an approximation using the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to numerical values ​​is optional and, for example, indicates + / - 10%.

Claims

1. An apparatus for homogenizing one or more regions within a plurality of electrochemical cells, the apparatus comprising: Multiple magnetic flux generators are each configured to generate a corresponding changing magnetic field passing through at least one of the multiple electrochemical cells; The plurality of magnetic flux generators and the plurality of electrochemical cells are arranged in an alternating manner.

2. The apparatus according to claim 1, wherein, The device includes one or more battery stations, each configured to accommodate a corresponding plurality of the electrochemical cells.

3. The magnetic flux generator according to claim 2, wherein, The plurality of magnetic flux generators are arranged within each battery station such that each battery station includes at least one of the plurality of magnetic flux generators.

4. The apparatus according to claim 3, wherein, Each battery station includes at least as many magnetic flux generators as there are electrochemical cells.

5. The apparatus according to claim 4, wherein, The magnetic flux generator and the electrochemical cell are arranged alternately in each / every battery station.

6. The apparatus according to any one of claims 2-4, wherein, The one or more battery stations are multiple battery stations.

7. The apparatus according to claim 6, wherein, The multiple magnetic flux generators are interspersed among the multiple battery stations.

8. The magnetic flux generator according to claim 7, wherein, The magnetic flux generators and the battery stations are arranged such that each battery station is sandwiched between a corresponding pair of the plurality of magnetic flux generators.

9. The apparatus according to any one of claims 3-8, wherein, The plurality of battery stations are housed within a container having one or more walls, and at least one of the plurality of magnetic flux generators is arranged outside the container and adjacent to a corresponding one of the one or more walls of the container.

10. The apparatus according to any one of the preceding claims, wherein, The device includes at least one power source configured to supply power to the plurality of electrochemical cells.

11. The apparatus according to claim 10 when dependent on claim 6, wherein, The at least one power source is a plurality of power sources, each configured to supply power to the electrochemical cells of a corresponding one of the plurality of battery stations.

12. The apparatus according to claim 10 or 11, wherein, The at least one power source is further configured to supply power to the plurality of magnetic flux generators.

13. The apparatus according to any one of claims 10-12, wherein, Each flux generator is connected to a shared or corresponding power supply device to receive power from it, wherein the shared or corresponding power supply device is different from the at least one power source.

14. The apparatus according to claim 13, wherein, When each flux generator is connected to the shared power supply, a subset of the plurality of flux generators are each connected to the shared power supply via a corresponding shared electrical connection.

15. The apparatus according to any one of the preceding claims, wherein, Each changing magnetic field is one of the following or any combination thereof: rotation, pulse, and / or oscillation.

16. The apparatus according to any one of the preceding claims, wherein, Each changing magnetic field can be controlled to change in one, two, or three spatial dimensions.

17. The apparatus according to any one of the preceding claims, wherein, Each flux generator includes one or more magnetic field sources.

18. The apparatus according to claim 17, wherein, At least one of the one or more magnetic field sources includes a permanent magnet and a corresponding mechanism for moving the permanent magnet and / or one or more of the electrochemical cells.

19. The apparatus according to claim 17, wherein, At least one of the one or more magnetic field sources is an electromagnet.

20. The apparatus according to claim 19, wherein, Each electromagnet is an air-core electromagnet that extends longitudinally to define a space for accommodating a corresponding electrochemical cell among the one or more electrochemical cells.

21. The apparatus according to any one of claims 17-20, wherein, The one or more magnetic field sources are multiple magnetic field sources.

22. The apparatus according to claim 21, wherein, The multiple magnetic field sources are arranged in a common plane.

23. The apparatus according to any one of the preceding claims, further comprising a controller configured to: At each change in the plurality of changing magnetic fields, the electrochemical overpotential of each of the plurality of electrochemical cells is monitored; and The optimal value is selected for each varying magnetic field to minimize each electrochemical overpotential.

24. A method for homogenizing one or more regions within a plurality of electrochemical cells, the method comprising the steps of: Multiple magnetic flux generators are available; The plurality of magnetic flux generators and the plurality of electrochemical cells are arranged in an alternating manner; as well as A corresponding changing magnetic field is generated through one or more of the magnetic flux generators, passing through at least one of the plurality of electrochemical cells.

25. An apparatus for homogenizing one or more regions within a plurality of electrochemical cells, the apparatus comprising: Multiple magnetic flux generators are each configured to generate a corresponding magnetic field passing through at least one of the multiple electrochemical cells; The plurality of magnetic flux generators and the plurality of electrochemical cells are arranged in an alternating manner.

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