magnetic flux generator

Abstract

The present invention provides a magnetic flux generator for enhancing ion transport in an electrochemical cell, the magnetic flux generator comprising one or more magnetic field sources each configured to generate a respective magnetic field, each magnetic field being individually controllably variable in three spatial dimensions.

Description

[Technical Field]

[0001] The present invention relates to magnetic flux generators, particularly but not exclusively to magnetic flux generators for enhancing ion transport in electrochemical cells. [Background technology]

[0002] Electrochemical cells are essential to many electrical systems, particularly portable devices such as mobile phones and laptops, and increasingly electric vehicles.

[0003] The portability of electronic devices / vehicles depends on the performance of their cells. In general, it is desirable to have cells with high capacity and short charging times to increase the ratio between the time the device / vehicle can operate independently of an external power source and the time it must be connected to an external power source for charging.

[0004] Various types and configurations of electrochemical cells can be selected based on size, shape, voltage, current, and other requirements. Examples of common cell shapes are pouch cells, prismatic cells, cylindrical cells, Swagelok cells, and coin cells. Cells may also be connected within a battery to provide the appropriate voltage and / or current for the application.

[0005] If a cell is charged too rapidly, many undesirable operating conditions can occur, such as dendrite formation, metal plating, and current hot spots, each of which can potentially increase the likelihood of short circuits and damage to the cell. A common method for rapidly charging a cell while avoiding overcharging is to provide a constant current in a first charging phase until a predetermined voltage is reached in the cell, and then hold the voltage constant in a second charging phase while the current decays to ensure the cell reaches capacity. The first charging phase rapidly increases the charge in the cell, while the second charging phase is slower.

[0006] It is known that providing a varying magnetic field through an electrochemical cell can enhance the performance of the cell (see UK Patent Application No. 201900171(A)). However, the present invention addresses the technical challenges associated with controlling and implementing this concept.

[0007] The present invention has been devised based on the above considerations. Summary of the Invention

[0008] The present invention provides a magnetic flux generator for enhancing ion transport in an electrochemical cell, the magnetic flux generator comprising one or more magnetic field sources each configured to generate a respective magnetic field, each magnetic field being individually controllably variable in three spatial dimensions.

[0009] Generally, applying a varying magnetic field that is variable in three spatial dimensions through an electrochemical cell means that the direction of magnetic flux within the cell changes over time, which can enhance ion transport within the cell and consequently improve the rate of charge and / or discharge of the cell, as well as the capacity of the cell.

[0010] The magnetic flux generator of the present invention generates a total varying magnetic field that is provided by one or more magnetic fields together. By placing an electrochemical cell in the total varying magnetic field or in selected subsections of one or more magnetic fields, ion transport through the cell can be enhanced. Advantageously, by individually and controllably varying each magnetic field in three spatial dimensions, precise and accurate control of the change in magnetic flux through the electrochemical cell is possible. This ensures that the enhancement of ion transport within the cell can be optimized.

[0011] Optional features of the invention are described below. The invention includes the described embodiments and any combination of features except where such a combination is clearly not permitted or explicitly avoided.

[0012] In addition to the three spatial dimensions, the polarity and / or magnitude of each magnetic field may also be varied to change the distribution and / or magnitude of the total varying magnetic field.

[0013] Optionally, each magnetic field is individually controllably varied over time, either continuously or incrementally, for example each magnetic field may have a sinusoidal or step waveform function.

[0014] Optionally, each magnetic field is individually controllably varied to be pulsed, rotated, and / or oscillated. Rotation of each magnetic field may be about an axis having a component perpendicular to the direction of the respective magnetic field. Rotation of each magnetic field may be about an axis having a component parallel to the direction of the respective magnetic field. Rotation of each magnetic field may be about an axis having a component perpendicular to the direction of current flow in the electrochemical cell. Rotation of each magnetic field may be about an axis having a component parallel to the direction of current flow in the electrochemical cell. Each rotating magnetic field may be provided by a rotating permanent magnet, temporary magnet, or electromagnet, or by an array of electromagnets that are sequentially actuated to effectively rotate each magnetic field.

[0015] Optionally, the one or more magnetic field sources are multiple magnetic field sources, in which case the total changing magnetic field generated by the magnetic flux generator is provided by multiple changing magnetic fields generated by the multiple magnetic field sources.

[0016] Optionally, the multiple magnetic field sources are arranged in a common plane. For example, the magnetic flux generator may comprise a planar (i.e., flat) mechanical support configured to support the multiple magnetic field sources. The magnetic field sources may be arranged in an array or grid. Advantageously, such a planar magnetic flux generator may be arranged, for example, parallel to one or more planar electrochemical cells, such as pouches or prisms, for enhanced ion transport. Alternatively, each electrochemical cell (e.g., cylindrical) may be arranged above (i.e., spaced apart from and near) each or several of the magnetic field sources to achieve the same beneficial effect.

[0017] Optionally, the magnetic flux generator is incorporated inside the electrochemical cell. For example, if the electrochemical cell is a flat cell (e.g., a pouch or prism), the magnetic field source may be located between the layers of the electrochemical cell (e.g., between its electrodes and within its electrolyte), or on the interior wall of the cell housing that encloses the electrodes and electrolyte of the electrochemical cell. Advantageously, incorporating a magnetic flux generator inside an electrochemical cell can ensure that the total changing magnetic field generated by the magnetic flux generator penetrates the cell uniformly, which can optimize the enhancement of ion transport within the cell.

[0018] Optionally, the magnetic flux generator is curved to at least partially surround the electrochemical cell. That is, the magnetic field source is arranged around a curve, an arc, a circle, or a polygon to provide the curved shape of the magnetic flux generator. The curve, arc, circle, or polygon may be provided by a curved, semicircular, circular, or polygonal mechanical support, respectively. Advantageously, such an arrangement allows the curved magnetic flux generator to at least partially surround an electrochemical cell, such as a cylindrical electrochemical cell. For example, the magnetic field source may comprise an octagonal mechanical support, and the magnetic field source may be arranged on each inner surface of the octagonal support to provide a central open space for receiving, for example, a cylindrical electrochemical cell. Advantageously, this can ensure that an electrochemical cell received within the central open space of the magnetic flux generator is uniformly penetrated by the total changing magnetic field.

[0019] The choice of magnets providing the magnetic field sources is not particularly limited, so long as each magnetic field source is capable of generating a respective magnetic field that is individually controllably variable in three spatial dimensions. For example, at least one of the one or more magnetic field sources may be a temporary magnet.

[0020] Optionally, at least one of the one or more magnetic field sources is a permanent magnet coupled to a mechanism for moving the permanent magnet. Generally, the magnetic field generated by the permanent magnet can be varied by changing the direction and / or speed at which the permanent magnet is moved by the respective mechanism. To completely "switch off" the transient nature of the permanent magnet, the permanent magnet is held static.

[0021] Optionally, at least one of the one or more magnetic field sources is an electromagnet. The electromagnet may be any type of electromagnet. Electromagnets generally comprise a coil of wire wound around a core. For example, the core may be a metal core (e.g., a ferromagnetic core) or may be an air-filled space at the center of the electromagnet, i.e., an air core. Each electromagnet is configured to be coupled to a power source. Controlling each electromagnet may include changing the amount of power and / or the direction of the current supplied to the electromagnet by the power source. For example, it may be desirable to switch one or more electromagnets off (i.e., not supply power to them) to change the total changing magnetic field. Additionally or alternatively, it may be desirable to provide currents having different directions to different electromagnets to change the magnetic polarity of the respective generated magnetic fields.

[0022] Optionally, each electromagnet is an air-core electromagnet. By air-core electromagnet, we mean herein a coil of wire (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, the magnetic flux generator may be provided by stacking multiple air-core electromagnets to provide a shared air core that is common to all the air-core electromagnets. The air core / shared air core can house an electrochemical cell, for example, a cylindrical cell.

[0023] If the electrochemical cell is cylindrical and each magnetic field source is an electromagnet, the magnetic flux generator may be incorporated inside the cell by winding each electromagnet around and / or through a layer (e.g., electrode and / or electrolyte) of the cylindrical electrochemical cell.

[0024] Optionally, the magnetic flux generator further comprises a controller configured to control each of the three spatial dimensions of the magnetic field / magnetic fields. For example, the magnetic flux generator may be configured to select values ​​for each of the three spatial dimensions of the magnetic field / magnetic fields. Furthermore, the controller may be configured to select values ​​for any one or any combination of the polarity, magnitude, phase, amplitude, and / or frequency of the magnetic field / magnetic fields. The controller may be configured to control the magnetic field / magnetic fields (e.g., by selecting values ​​for each of the three spatial dimensions and, optionally, for the polarity and / or magnitude and / or phase and / or amplitude and / or frequency of the magnetic field / magnetic fields) based on any one or any combination of electrical, magnetic, optical, and / or acoustic measurements performed on one or more electrochemical cells located in at least one of the one or more magnetic fields. The electrical, magnetic, optical, and / or acoustic measurements may be performed when each of the one or more magnetic fields is individually, controllably varied in the three spatial dimensions.

[0025] The magnetic flux generator 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 sensors, Gauss sensors, optical sensors, and / or acoustic sensors. The controller may be communicatively connected to the sensor unit.

[0026] Optionally, the controller may be configured to monitor the electrochemical overpotential of each of one or more electrochemical cells located within at least one of the one or more magnetic fields as each of the one or more magnetic fields is individually and controllably varied. The controller may be configured to select optimal values ​​for each of the three spatial dimensions of each magnetic field to minimize each electrochemical overpotential. The monitoring may be discrete or continuous. Furthermore, the controller may select optimal values ​​for any one or any combination of the polarity, magnitude, phase, amplitude, and / or frequency of each magnetic field to minimize the electrochemical overpotential. The controller may repeat the monitoring and selection of optimal values ​​of each electrochemical overpotential as many times as necessary to minimize each electrochemical overpotential.

[0027] Optionally, the controller is configured to monitor each electrochemical overpotential via direct overpotential measurement. Direct overpotential measurement may be performed, for example, using electrochemical impedance spectroscopy (involving impedance measurements at multiple frequencies or fixed frequency impedance). Alternatively, to monitor electrochemical overpotential, any one or any combination of the amplitude, phase shift, and frequency of the electrochemical potential or current of the / each cell may be measured.

[0028] Optionally, the controller is configured to monitor each electrochemical overpotential using any one or any combination of electrical, magnetic, optical, and / or acoustic measurements performed on one or more electrochemical cells, For example, such measurements may be used as a proxy to determine the electrochemical overpotential of each electrochemical cell.

[0029] Optionally, the controller is electrically connected to both the magnetic flux generator and the one or more electrochemical cells, such that the controller can directly monitor each electrochemical overpotential and control the one or more magnetic field sources to individually and controllably vary each magnetic field.

[0030] 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 both the magnetic flux generator and the one or more electrochemical cells and communicatively connected to a sensor unit configured to perform the electrical, magnetic, optical, and / or acoustic measurements. For example, the sensor unit may include any one or any combination of Hall sensors, Gaussian sensors, optical sensors, and / or acoustic sensors. This is because the electrical, magnetic, optical, and acoustic measurements can indicate the state of charge / health of the electrochemical cells. For example, the optical sensor may be configured to measure deformation and / or accumulation / loss of material at selected locations on the one or more electrochemical cells. The acoustic sensor may be configured to measure a decibel response to an acoustic signal transmitted to / reflected from one or more selected locations on the one or more electrochemical cells. Advantageously, the decibel response correlates with the state of charge at the selected locations on the one or more electrochemical cells. [Brief explanation of the drawings]

[0031] BRIEF DESCRIPTION OF THE DRAWINGS Embodiments and experiments illustrating the principles of the present invention are described below with reference to the accompanying drawings. [Figure 1A] 1A-1C are schematic diagrams illustrating magnetic fields generated by two different magnetic field source configurations. [Figure 1B] 1A-1C are schematic diagrams illustrating magnetic fields generated by two different magnetic field source configurations. [Figure 2] FIG. 1 shows a schematic diagram of a magnetic flux generator and a flat electrochemical cell according to an embodiment of the present invention. [Figure 3] FIG. 2 is a schematic diagram of the magnetic flux generator of FIG. 1 and a cylindrical electrochemical cell. [Figure 4] FIG. 1 is a schematic diagram of a magnetic flux generator and a cylindrical electrochemical cell according to an embodiment of the present invention. [Figure 5A]1A-1C show schematic diagrams of a magnetic flux generator and a cylindrical electrochemical cell according to an embodiment of the present invention in two respective configurations. [Figure 5B] 1A-1C show schematic diagrams of a magnetic flux generator and a cylindrical electrochemical cell according to an embodiment of the present invention in two respective configurations. [Figure 6A] 1A and 1B show schematic diagrams of variations of a magnetic flux generator according to an embodiment of the present invention integrated inside a flat electrochemical cell; [Figure 6B] 1A and 1B show schematic diagrams of variations of a magnetic flux generator according to an embodiment of the present invention integrated inside a flat electrochemical cell; [Figure 7A] 10A-10C are schematic diagrams illustrating variations of a magnetic flux generator according to an embodiment of the present invention incorporated inside a cylindrical electrochemical cell. [Figure 7B] 10A-10C are schematic diagrams illustrating variations of a magnetic flux generator according to an embodiment of the present invention incorporated inside a cylindrical electrochemical cell. [Figure 8A] 4A and 4B show schematic perspective and simplified top views of a magnetic flux generator of the type shown in FIGS. 2 and 3; [Figure 8B] FIG. 10 illustrates how the total varying magnetic field produced by the magnetic flux generator can be controlled over time by sequentially operating individual magnetic field sources. [Figure 9A] FIG. 10 shows a diagram illustrating the current supplied to each magnetic field source as a function of time. [Figure 9B] FIG. 10 shows a diagram illustrating the current supplied to each magnetic field source as a function of time. [Figure 9C] FIG. 10 shows a diagram illustrating the current supplied to each magnetic field source as a function of time. [Figure 9D] FIG. 10 shows a diagram illustrating the current supplied to each magnetic field source as a function of time. [Figure 9E] FIG. 10 shows a diagram illustrating the current supplied to each magnetic field source as a function of time. [Figure 10] FIG. 1 is a schematic diagram of a magnetic flux generator, an electrochemical cell, and a controller. [Figure 11] FIG. 11 is a diagram schematically illustrating a modification of the configuration of FIG. 10 further including a sensor unit. DETAILED DESCRIPTION OF THE INVENTION

[0032] Aspects and embodiments of the present invention are described below with reference to the accompanying drawings. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned herein are incorporated by reference.

[0033] Generally, a magnetic field source, such as a permanent magnet, temporary magnet, or electromagnet, generates a field that can be represented by magnetic field lines. This physical phenomenon is described with reference to FIGS. 1A-1B. Specifically, FIG. 1A shows a magnetic field source 6 having a south pole S and a north pole N that generates a magnetic field represented by magnetic field lines 7. Similarly, FIG. 1B shows two magnetic field sources 6 of the type shown in FIG. 1A arranged such that the south pole S of the first magnetic field source is adjacent to the north pole N of the second magnetic field source. This arrangement of magnetic field sources 6 generates a total magnetic field represented by their respective magnetic field lines 7. Thus, the magnetic fields generated by magnetic field sources that are sufficiently close in space interact with each other, thus generating a total magnetic field. The present invention relies, at least in part, on this phenomenon.

[0034] The present invention provides a magnetic flux generator comprising one or more magnetic field sources, each configured to generate a respective magnetic field that is individually and controllably variable in three spatial dimensions. The magnetic flux generator generates a total changing magnetic field that the one or more magnetic fields together provide. Each magnetic field can be individually and controllably varied over time, either continuously or incrementally.

[0035] A first embodiment of the present invention will now be described with reference to Figure 2, which shows a schematic representation of a magnetic flux generator 1 and a planar electrochemical cell 2. The magnetic flux generator 1 comprises a plurality of magnetic field sources 6 arranged in a common plane and supported by a planar (i.e. flat) mechanical support 8. The magnetic field sources 6 are arranged in a grid, although other arrangements are possible.

[0036] In this example, the multiple magnetic field sources 6 are multiple electromagnets. Each electromagnet comprises a coil of wire wound around a core (e.g., a metal core, such as a ferromagnetic core, or an air core provided by an air-filled space in the center of the electromagnet). Each electromagnet 6 is coupled to a power source (not shown) via an electrical connection 9 to generate its respective magnetic field. Controlling each electromagnet may include varying the amount of power and / or the direction of current supplied to the electromagnet by the power source. For example, it may be desirable to switch one or more electromagnets off (i.e., not supply power to them) to vary the total varying magnetic field generated by the magnetic flux generator 1. Additionally or alternatively, it may be desirable to provide currents having different directions to different electromagnets to vary the magnetic polarity (i.e., north or south) of each generated magnetic field.

[0037] Electrochemical cell 2 is a flat electrochemical cell that may be a prismatic cell or a pouch cell. In this example, the flat electrochemical cell is a pouch cell including a housing 5 (the floor of which is shown in FIG. 2 ), a pair of electrodes 13 that define a current path and are spaced apart by an electrolyte 12, and a pair of tabs 4. The electrodes 13 and electrolyte 12 (e.g., as shown in FIGS. 6A and 6B ) together form an electrode assembly 3. The electrochemical cell 2 is positioned in spatial proximity to a magnetic flux generator 1 so as to be permeated by at least one of the magnetic fields generated by multiple magnetic field sources 6. Specifically, in this example, cell 2 is above (i.e., parallel to and spaced apart from) magnetic flux generator 1.

[0038] The magnetic flux generator 1 of FIG. 1 can be used with different types of electrochemical cells in addition to pouches and prisms. For example, the magnetic flux generator can be used with coin cells and cylindrical cells to enhance their ion transport. This is shown in FIG. 3, where the magnetic flux generator 1 is positioned in close spatial proximity to a cylindrical cell 2. The cylindrical cell is positioned above the magnetic flux generator so that it is penetrated by at least one of the magnetic fields generated by multiple magnetic field sources 6. As previously mentioned, the cylindrical cell 2 includes an electrode assembly 3 enclosed within a housing 5.

[0039] Multiple magnetic field sources 6 may be arranged on mechanical supports 8 of different shapes, not just flat ones. For example, the mechanical supports 8 may be curved, semicircular, circular, or polygonal. Thus, magnetic field sources may be arranged around a curve, an arc, a circle, or a polygon. Such a magnetic flux generator 1 is called a curved magnetic flux generator and is exemplified by the embodiment shown in FIG. 4. In this example, the mechanical supports 8 are octagonal, and magnetic field sources 6 are arranged on the inner surface of each octagonal support to provide a central empty space. This central empty space is intended to receive an electrochemical cell, and a cylindrical electrochemical cell 2 is inserted into it, as shown in FIG. 4. Advantageously, this ensures that the total changing magnetic field generated by the magnetic flux generator 1 uniformly penetrates the electrochemical cell 2 received within the central empty space.

[0040] If each magnetic field source 6 is an air-core electromagnet 16 (i.e., a coil of wire (solenoid) with a central air-filled space defined by the coil and no solid core), the magnetic flux generator 1 can be provided by stacking multiple air-core electromagnets 16 to provide a shared air core that is common to all of the air-core electromagnets. This is shown in FIG. 5A. The shared air core can house an electrochemical cell. For example, as shown in FIG. 5A, a cylindrical electrochemical cell 2 can be inserted into the shared air core to obtain the arrangement shown in FIG. 5B. Thus, the magnetic flux generator 1 at least partially surrounds the electrochemical cell 2.

[0041] As described above with reference to Figures 2 to 5B, the magnetic flux generator 1 can be located spatially adjacent to and external to the electrochemical cell 2. However, it is also possible to incorporate the magnetic flux generator inside the electrochemical cell. Examples of these are described with reference to Figures 6A to 7B.

[0042] 6A and 6B, the magnetic flux generator 1 comprises multiple magnetic field sources 6 (three of which are shown) integrated inside a flat electrochemical cell 2 (e.g., a pouch or prism). In the example of FIG. 6A, the magnetic field sources 6 are located on the interior walls of a cell housing 5 that encloses the electrodes 13 and electrolyte 12 of the electrochemical cell 2. In contrast, in FIG. 6B, the magnetic field sources 6 are located between the layers of the electrochemical cell 2, i.e., between the electrodes 13 and within the electrolyte 12.

[0043] Alternatively, the magnetic flux generator 1 may be incorporated within a non-planar electrochemical cell, such as a cylindrical cell. This is shown in FIGS. 7A and 7B. In the variation of FIG. 7A, the magnetic flux generator 1 includes a single magnetic field source 6, which is a permanent magnet 17 coupled to a mechanism (not shown) for moving the permanent magnet. The permanent magnet 17 is shown outside the cell at the bottom of FIG. 7A for reference. In an embodiment, the magnetic field source 6 (i.e., the permanent magnet 17 coupled to its mechanism) is incorporated within the cell 2 on the inner wall of the cell housing 5 such that the magnetic field source 6 longitudinally spaces the inner wall of the cell housing from the electrode assembly 3. As previously mentioned, the selection of the magnetic field source 6 is not particularly limited; in addition to a permanent magnet, the magnetic field source may be an electromagnet or a temporary magnet.

[0044] Indeed, Figure 7B shows an alternative arrangement in which the magnetic flux generator 1 is provided by multiple air-core electromagnets 16 stacked to provide a shared air core as in the example of Figures 5A-5B. An example of a single air-core electromagnet 16 is shown for reference at the bottom of Figure 7B, below the electrochemical cell. The air-core electromagnets 16 are each wound around and / or through a layer (e.g., electrode assembly 3) of the cylindrical electrochemical cell 2.

[0045] Modifications to the above embodiments are possible. The choice of magnets providing the magnetic field sources is not particularly limited, so long as each magnetic field source can generate a respective magnetic field that is individually controllably variable in three spatial dimensions. The electrochemical cell may be a battery. The battery may be a positive ion battery, and the current path may be in the direction of movement of positive ions. The battery may be a lithium ion battery. Alternatively, the battery may be a negative ion battery, and the current path may be in the direction of movement of negative ions. The cell may be for powering an electric vehicle, a mobile phone, a laptop computer, a tablet, or other portable or stationary device. The electrochemical cell may be a fuel cell.

[0046] As noted above, each magnetic field source of the present invention is configured to generate a respective magnetic field that is individually and controllably variable in three spatial dimensions, so as to ensure that the total magnetic field generated by the magnetic flux generator can be varied.

[0047] An example of individually and controllably varying each of the four magnetic fields in three spatial dimensions is described with reference to Figures 8A and 8B. A magnetic flux generator 1 is shown in Figure 8A and includes four magnetic field sources 6a, 6b, 6c, and 6d in a 2x2 grid arrangement on a planar mechanical support 8. A schematic top view of the magnetic flux generator is shown on the right side of Figure 8A, showing the 2x2 grid with the four magnetic field sources 6a, 6b, 6c, and 6d. By individually and controllably varying each magnetic field generated by each of the magnetic field sources 6a, 6b, 6c, and 6d, the total varying magnetic field generated by the magnetic flux generator 1 can be varied.

[0048] FIG. 8B illustrates how a fully variable magnetic field rotating circularly in a clockwise direction (as shown in the simplified grid of FIG. 8A) can be achieved by sequentially controlling four magnetic field sources. Specifically, each of the four magnetic field sources is controlled to have a predetermined polarity (south south or north north) that can be reversed / alternated or switched off completely. Generally, if the magnetic field sources are permanent magnets, they can be moved to a specific orientation (e.g., rotated in a specific direction) to control their polarity or left stationary to switch them off. In the example of FIGS. 8A and 8B, magnetic field sources 6a, 6b, 6c, and 6d are electromagnets. Thus, in FIG. 8A, each electromagnet can be switched off by not supplying power to it, or its polarity can be changed between north and south by supplying current with a specifically selected direction. That is, by supplying current from A to B or from B to A through electrical connection 9 (see FIG. 8A), either north-north or south-south polarity is produced on the surface of the array.

[0049] The polarity (N, S) of each magnetic field source 6a, 6b, 6c, and 6d can be changed in a stepwise manner, as shown in FIG. 8B, or can be changed gradually over time. FIGS. 9A-9E illustrate this by showing exemplary time-evolving current functions representing the current supplied to the different magnetic field sources. FIG. 9A shows a current function that evolves in a stepwise manner over time. In contrast, FIGS. 9B-9E show current functions that have a sinusoidal shape and evolve gradually over time. In the example of FIGS. 9C-9E, the total current supplied to magnetic flux generator 1 is represented by a superposition of multiple current functions, e.g., two sinusoidal waves that are out of phase and / or have different amplitudes and / or different frequencies. The superposition of multiple current functions (each corresponding to a respective magnetic field source) can be said to generate a "magnetic field signature" of the total changing magnetic field generated by magnetic flux generator 1.

[0050] The magnetic field generated by each magnetic field source can be individually and controllably varied by a controller 10 included in the magnetic flux generator 1. This is shown in Figures 10 and 11. In Figure 10, the controller is electrically connected to the magnetic flux generator 1 and to an electrochemical cell 2 located within at least one of the magnetic fields generated by the magnetic field sources.

[0051] In the examples of FIGS. 10 and 11 , the electrochemical cell 2 is a flat cell atop the magnetic flux generator 1. The controller 10 is configured to monitor the electrochemical overpotential of the electrochemical cell as each magnetic field is individually and controllably varied (e.g., as described with reference to FIGS. 8A-9E ). The controller 10 is further configured to select optimal values ​​for each of the three spatial dimensions of each magnetic field to minimize the electrochemical overpotential. Optionally, the controller may also select optimal values ​​for any one or any combination of the polarity, magnitude, phase, amplitude, and / or frequency of each magnetic field to minimize the electrochemical overpotential. The controller 10 may repeat the monitoring of the electrochemical overpotential and the selection of optimal values ​​as many times as necessary to minimize the electrochemical overpotential. The optimal parameters selected for each magnetic field need not be identical. In fact, the controller may select different optimal parameter values ​​for each magnetic field, which can help improve the uniformity of ion transport enhancement across the electrochemical cell.

[0052] The example controller 10 shown in FIG. 10 is configured to monitor each electrochemical overpotential via direct overpotential measurement. Direct overpotential measurement can be performed, for example, using electrochemical impedance spectroscopy. Alternatively, to monitor electrochemical overpotential, any one or any combination of the amplitude, phase shift, and frequency of each cell's electrochemical potential or current can be measured. The controller 10 can measure these via electrical connections to the electrochemical cells 2.

[0053] Alternatively, the electrochemical overpotential of the electrochemical cell 2 may be monitored using any one or any combination of electrical, magnetic, optical, and / or acoustic measurements performed on the cell. These measurements can serve as a proxy for determining the electrochemical overpotential. A corresponding variant arrangement is shown in FIG. 11, in which the controller 10 is further communicatively and / or electrically connected to a sensor unit 11 comprising a plurality of sensors 18. The plurality of sensors 18 may include Hall sensors, Gaussian sensors, optical sensors (e.g., measuring deformation and / or accumulation / loss of material at selected locations of the electrochemical cell 2), and / or acoustic sensors (e.g., measuring decibel responses to acoustic signals transmitted to / reflected from selected locations on electrochemical cell 2). FIG. 11 further illustrates a region 2' on electrochemical cell 2 that exhibits different performance than the rest of the cell, e.g., degraded performance. Accordingly, controller 10 can detect this discrepancy in performance via overpotential measurements and set optimal parameter values ​​for a particular magnetic field source / group of magnetic field sources whose magnetic fields penetrate into underperforming region 2' to account for the localized lower performance, thereby homogenizing macroscopic (overall) cell performance across its volume.

[0054] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, and expressed in a particular form, or as means for performing a disclosed function, or as methods or processes for obtaining a disclosed result, can, where appropriate, be utilized separately or in any combination of such features to realize the invention in diverse forms thereof. While the present invention has been described in conjunction with the exemplary embodiments set forth above, many equivalent modifications and variations will be apparent to those skilled in the art given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes can be made to the described embodiments without departing from the spirit and scope of the invention.

[0055] For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purpose of improving the understanding of the reader, and the inventors do not wish to be bound by any of these theoretical explanations.

[0056] Any section headings used herein are for organizational purposes only and should not be construed as limiting the subject matter described.

[0057] Throughout this specification, including the claims which follow, unless the context requires otherwise, the words "comprise" and "include," and variations such as "comprises," "comprising," and "including," are understood to imply the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of any other integer or step or group of integers or steps.

[0058] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" in connection with numerical values ​​is optional and means, for example, + / - 10%.

Claims

1. 1. A magnetic flux generator for enhancing ion transport in an electrochemical cell, comprising: one or more magnetic field sources, each configured to generate a respective magnetic field; A magnetic flux generator, each magnetic field being individually controllably variable in three spatial dimensions.

2. Further comprising a controller, The controller monitoring an electrochemical overpotential of each of one or more electrochemical cells located within at least one of the one or more magnetic fields as each of the one or more magnetic fields is individually controllably varied; and 10. The magnetic flux generator of claim 1, configured to select optimal values ​​for each of the three spatial dimensions of each magnetic field to minimize each electrochemical overpotential.

3. 3. The magnetic flux generator of claim 2, wherein the controller is configured to monitor each electrochemical overvoltage via direct overvoltage measurement.

4. 3. The magnetic flux generator of claim 2, wherein 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.

5. 4. The magnetic flux generator of claim 2 or 3, wherein the controller is electrically connected to both the magnetic flux generator and the one or more electrochemical cells.

6. The controller an electrical connection between the magnetic flux generator and the one or more electrochemical cells; 5. The magnetic flux generator of claim 4, communicatively connected to a sensor unit configured to perform the electrical, magnetic, optical, and / or acoustic measurements.

7. A magnetic flux generator according to any preceding claim, wherein the or each magnetic field is individually controllably varied over time, either continuously or incrementally.

8. A magnetic flux generator according to any preceding claim, wherein the or each magnetic field is individually controllably varied to be pulsed, rotating and / or oscillating.

9. A magnetic flux generator according to any one of claims 1 to 8, wherein the one or more magnetic field sources are a plurality of magnetic field sources.

10. The magnetic flux generator of claim 9 , wherein the plurality of magnetic field sources are arranged in a common plane.

11. The magnetic flux generator of claim 10 comprising a planar mechanical support configured to support the plurality of magnetic field sources.

12. A magnetic flux generator according to any one of claims 1 to 11, wherein the magnetic flux generator is integrated inside an electrochemical cell.

13. 10. The magnetic flux generator of claim 9, wherein the magnetic flux generator is curved to at least partially surround an electrochemical cell.

14. A magnetic flux generator according to any one of the preceding claims, wherein at least one of the one or more magnetic field sources is a permanent magnet coupled to a mechanism for moving the permanent magnet.

15. A magnetic flux generator according to any preceding claim, wherein at least one of the one or more magnetic field sources is an electromagnet.

16. 16. A magnetic flux generator according to claim 15, wherein the or each electromagnet is an air core electromagnet.

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