Method of enhancing electrochemical cell performance

Abstract

To provide a method of enhancing the performance of an electrochemical cell having first and second electrodes and an electrolyte between the first and second electrodes.SOLUTION: There is provided an apparatus for enhancing and monitoring the performance of a cell 1 during charging or discharging. The cell 1 is located on top of a rotating magnetic field generator 2, and connected to a potentiostat and a computer 3 via terminals 4. The potentiostat controls the potential across the cell 1 and may charge or discharge the cell 1. The computer monitors the current, capacity and / or voltage of the cell 1. The rotating magnetic field generator 2 provides a rotating magnetic field through the cell 1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] FIELD OF THEINVENTION The present invention relates to the performance of electrochemical cells, and in particular, but not exclusively, to improving the charge and discharge rates and capacity of electrochemical cells. [Background technology]

[0002] background Electrochemical cells are essential to many electrical systems, especially portable devices such as mobile phones and laptops, and even electric automobiles.

[0003] The portability of an electronic device / vehicle depends on the performance of the cells. In general, it is desirable to have cells with large capacity and short charging times to increase the ratio between the time the device / vehicle can operate independently from an external power source and the time the device / vehicle 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 include pouch cells, cylindrical cells, Swagelok cells, and coin cells. Cells can also be connected to batteries to provide the appropriate voltage and / or current for the application.

[0005] If a cell is charged too quickly, a number of undesirable operating conditions can occur, such as dendrite formation, metal plating and current hot spots, which can potentially increase the likelihood of causing short circuits and cell damage, respectively.

[0006] A common method of charging a cell quickly 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 in a second charging phase, hold the voltage constant while the current decays to ensure the cell is at full capacity. The first charging phase rapidly builds up the charge in the cell, while the second charging phase is slower.

[0007] C-rate is a measure of the rate at which a cell is charged or discharged, and is the current divided by the capacity, with units per hour. Summary of the Invention [Means for solving the problem]

[0008] The present invention has been devised in light of the above considerations.

[0009] Summary of the Invention The present invention provides a method of enhancing the performance of an electrochemical cell having a first electrode and a second electrode and an electrolyte between the first electrode and the second electrode, the first and second electrodes defining a current path, the method comprising providing a changing magnetic field through the cell.

[0010] The changing magnetic field means that it aids in ion transport within the electrochemical cell, thereby improving the performance of the battery. Optionally, the cell may include a separator between the electrodes. Ion transport may be improved within the electrolyte, and / or the electrodes, and / or the separator. The changing magnetic field through the cell means that the magnitude and / or direction and / or distribution of the magnetic flux in the cell changes over time.

[0011] One of the cell properties that can be improved using the above method is the charge rate of the cell. Since ion transport in the cell is often the rate limiting process during charging, by assisting ion transport, the charging of the cell is accelerated. Another cell property that can be improved using the above method is the discharge rate, since ion transport is improved in a similar manner as during charging. Another cell property that can be improved using the above method is the capacity of the cell. This can be achieved by performing the above method on the cell during the formation of the cell or during operation.

[0012] The changing magnetic field may be a rotating magnetic field, and / or an oscillating magnetic field, and / or a pulsed magnetic field.

[0013] The changing magnetic field may have a direction that has a component perpendicular to the current path.The changing magnetic field may have a direction that has a component parallel to the current path.

[0014] The rotation of the magnetic field can be about an axis having a component perpendicular to the direction of the magnetic field.The rotation of the magnetic field can be about an axis having a component parallel to the direction of the magnetic field.

[0015] The rotation of the magnetic field can be about an axis having a component perpendicular to the direction of the current path.The rotation of the magnetic field can be about an axis having a component parallel to the direction of the current path.

[0016] The rotating magnetic field may be provided by a spinning permanent or temporary magnet or electromagnet, or by an array of electromagnets that are sequentially activated to effectively rotate the magnetic field.

[0017] The electrochemical cell may be a battery. The battery may be a coin cell, a cylindrical cell, a prismatic cell or a pouch cell.

[0018] 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.

[0019] The cell may be for powering an electric vehicle, a mobile phone, a laptop computer, a tablet or other portable or stationary device. The cell may be a fuel cell.

[0020] The electrochemical cell may be part of an array of two or more cells.

[0021] The magnetic field may be provided by a permanent magnet, or a temporary magnet, or an electromagnet.

[0022] The electrolyte may be a solid, liquid or gel. In particular, the electrolyte may be non-aqueous, including organic electrolytes.

[0023] A magnetic field generator may be provided for generating the varying magnetic field. The magnetic field generator may be internal to the cell or external to the cell.

[0024] In another aspect, the present invention provides a charge accelerator for enhancing the performance of an electrochemical cell, the apparatus being configured to carry out the method for enhancing the performance of an electrochemical cell described above.

[0025] In another aspect, the present invention provides a method of charging an electrochemical cell, the method comprising the step of providing a current or voltage from a power source to the cell while performing the method of enhancing the performance of the electrochemical cell described above. In this disclosure, charging a cell includes moving ions within the cell, whether imposed by a current or voltage, or by the spontaneous movement of ions.

[0026] In another aspect, the present invention provides a method of discharging an electrochemical cell, comprising the step of extracting a current or voltage from the cell while carrying out the method of enhancing the performance of an electrochemical cell described above.

[0027] In another aspect, the present invention provides a method of increasing the capacity of an electrochemical cell, the method comprising forming the electrochemical cell or during operation of the electrochemical cell while carrying out the method of enhancing the performance of the electrochemical cell described above.

[0028] The present invention includes combinations of the described embodiments and preferred features except where such combinations are expressly not permitted or explicitly avoided.

[0029] Diagram Overview BRIEF DESCRIPTION OF THE DRAWINGS Embodiments and experiments illustrating the principles of the present invention will now be discussed with reference to the accompanying drawings. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 illustrates a side view of an exemplary configuration of an apparatus for use in enhancing the performance of a cell. [Figure 2A] 1 shows a diagram of an exemplary configuration used to enhance the performance of a pouch cell; [Figure 2B] 1 shows a diagram of an exemplary configuration used to enhance the performance of a pouch cell; [Diagram 3] Cell capacity over time for a pouch cell is shown, where the pouch cell was charged at 0.841 A from 3.4 V to 4.2 V until 4.2 V was reached, and then held at a constant voltage while the current decayed and reached capacity, (i) with a changing magnetic field (dashed line) and (ii) with a constant magnetic field (solid line). [Figure 4]Shown is the current and voltage over time for a pouch cell that was charged at 0.841 A from 3.4 V to 4.2 V until 4.2 V was reached, and then held at a constant voltage while the current decayed and reached capacity, (i) in the presence of a rotating magnetic field (dashed line) and (ii) with a stationary magnetic field (solid line). [Diagram 5] Cell capacity over time for a pouch cell is shown, where the pouch cell was charged at 0.841 A from 3.4 V to 4.2 V until 4.2 V was reached, and then held at a constant voltage while the current decayed and reached capacity (i) in the presence of a rotating magnetic field (dashed line) and (ii) with a stationary magnetic field (solid line). [Figure 6] 3 shows the charge rate of a 400mAh pouch cell cycled with a rotating magnetic field and with a stationary magnetic field. [Figure 7] The time it takes to charge the 400mAh pouch cell of FIG. 6 using a rotating magnetic field and using a stationary magnetic field, along with the dimensions and characteristics of the cell used, are shown. [Figure 8] Charging rates of a 200mAh pouch cell at 4C with a rotating magnetic field and with a stationary magnetic field are shown. [Figure 9] The time it takes to charge the 200mAh pouch cell of Figure 8 at 4C with a rotating magnetic field and with a stationary magnetic field, along with the dimensions and characteristics of the cell used, are shown. [Figure 10A] 1 shows a diagram of an exemplary configuration used to enhance the performance of a Swagelok-type cell; [Figure 10B] 1 shows a diagram of an exemplary configuration used to enhance the performance of a Swagelok-type cell; [Figure 11] 1 shows the rates of charging at 1C, 2C and 3C performed on an LMO / graphite Swagelok cell with a rotating magnetic field and with a stationary magnetic field. [Figure 12] The time it takes to charge the LMO / graphite Swagelok cell of FIG. 11 with a rotating magnetic field and with a stationary magnetic field at 1C, 2C and 3C, along with the cell dimensions used, is shown. [Figure 13A] 1 shows a diagram of an exemplary configuration used to enhance the performance of a cylindrical cell, FIG. 2 shows a cross-sectional view along line AA. [Figure 13B] 1 shows a diagram of an exemplary configuration used to enhance the performance of a cylindrical cell. FIG. 2 shows a cross-sectional side view along line BB. [Figure 13C] 1 shows a diagram of an exemplary configuration used to enhance the performance of a cylindrical cell; [Figure 14] Shows charging rates of a cylindrical 2190mAh LG18650 cycled with a rotating magnetic field and the cell oriented in two directions 90 degrees apart from each other, as well as with a stationary magnetic field. [Figure 15] 15 shows the time it takes to charge the cylindrical 2190mAh LG18650 cell of FIG. 14 with a rotating magnetic field and the cell oriented in two directions 90 degrees apart from each other, and with a stationary magnetic field. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Detailed Description of the Invention Aspects and embodiments of the present invention will now be discussed with reference to the accompanying drawings. Further aspects and embodiments will become apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

[0032] The arrangement of the apparatus shown in Figure 1 can be used to enhance and monitor the performance of cell 1 while it is being charged or discharged. Cell 1 is placed on top of a rotating magnetic field generator 2. Cell 1 is connected to a potentiostat and a computer 3 via terminals 4. The potentiostat controls the potential across cell 1, allowing it to be charged or discharged. The computer monitors the current and / or capacity and / or voltage of cell 1. The rotating magnetic field generator 2 provides a rotating magnetic field through cell 1.

[0033] This configuration can be used to test cells, but if monitoring of cell 1 is not required, the potentiostat, computer 3 and terminals 4 can be removed and optionally replaced with a power source or drain for charging or discharging the cell.

[0034] In the configuration of FIG. 1, cell 1 is positioned on top of the rotating magnetic field generator 2, however, in other embodiments of the present invention, cell 1 and rotating magnetic field generator 2 may be oriented differently as long as the rotating magnetic field generator 2 is capable of generating a magnetic field that passes through cell 1.

[0035] The rotation of the magnetic field may be about an axis substantially parallel to the direction of the generated magnetic field. For example, the direction of the magnetic field generated in cell 1 may be substantially parallel to the direction between magnetic field generator 2 and cell 1, and the rotation of the magnetic field may be about an axis parallel to the direction between magnetic field generator 2 and cell 1, as shown in Figures 2A and 2B.

[0036] Alternatively, the rotation of the magnetic field may be about an axis that is substantially perpendicular to the direction of the generated magnetic field. For example, the direction of the magnetic field generated in cell 1 may be substantially perpendicular to the direction between magnetic field generator 2 and cell 1, and the rotation of the magnetic field may be about an axis that is parallel to the direction between magnetic field generator 2 and cell 1.

[0037] The rotating magnetic field generator 2 in the configuration of Figure 1 may be replaced with a varying magnetic field generator that generates a varying magnetic field that varies in another way, for example a varying magnetic field generator may be used to generate a rotating and / or oscillating and / or pulsating magnetic field.

[0038] The following apparatus and method examples demonstrate the effect of a changing magnetic field on the charging of several commercially available batteries. All of these examples show that the charging time of the cells is reduced in the presence of a changing magnetic field. The cells are of various geometries and chemical compositions and are described in more detail below.

[0039] In this disclosure, the term "under magnetic field conditions" refers to the presence of a changing magnetic field. In the examples described below, the results of charging a cell in the presence of a changing magnetic field are shown along with a comparative example of a cell in the absence of a changing magnetic field. The configurations used in the examples and comparative examples differ only in that the magnetic field provided in the comparative examples is constant in direction and magnitude, while the magnetic field provided in the examples is changing.

[0040] Figure 2 shows a configuration used to enhance the performance of pouch cell 11. A magnetic field generator 12 generates a magnetic field having a direction parallel to the direction shown by the arrow in Figure 2A. The generated magnetic field rotates in the direction shown by the arrow in Figure 2B. The magnetic field passes through pouch cell 11.

[0041] The magnetic field is offset from the axis of rotation to ensure that the magnetic flux within the cell varies over time.

[0042] The magnetic field generator 12 is an electromagnet powered by a power supply 15. A potentiostat 13 is connected to the pouch cell 11 and can be used to control the potential across the cell and to charge or discharge the cell.

[0043] The pouch cell 11 is formed from a first electrode and a second electrode separated from each other by an electrolyte. The electrodes are substantially parallel and extend across the length and width of the cell. The pouch cell 11 has contacts for each of the electrodes that can be connected to a potentiostat, as shown in FIG.

[0044] The pouch cell 11 is oriented so that the direction of the magnetic field passes through the first electrode, the electrolyte, and the second electrode of the cell. The direction of the magnetic field is parallel to the direction of the current path between the electrodes. The plane of rotation of the magnetic field is parallel to the plane of the electrodes.

[0045] 3 shows the capacity of pouch cell 11 when charged in the presence of a magnetic field generated by magnetic field generator 12 when the magnetic field is (i) rotating (indicated by dashed line) and (ii) not rotating (indicated by solid line). The pouch cell 11 was charged in two stages. In the first stage, the cell was charged at 0.841 A from 3.4 V to 4.2 V until 4.2 V was reached. Then, in the second stage, the cell was held at a constant voltage while the current decayed to reach capacity.

[0046] The first phase, where a constant current is applied to the cell, can be seen by the horizontal line portion of the current graph in Figure 4. The second phase, where the voltage is held constant and the current decays while reaching maximum capacity, can be seen where the current changes. The straight horizontal lines up to t=220 s and 300 s for the stationary and changing magnetic fields, respectively, represent the constant current portion of the charge, and from t onwards represent the constant voltage portion of the charge.

[0047] The magnetic field was generated by an electromagnet in magnetic field generator 12. During the cycle indicated by the dashed line, the electromagnet spun at 1160 rpm. The results show that the time it took to charge the cell was reduced by 68% by the presence of a rotating magnetic field.

[0048] Figure 4 shows the current and voltage during charging of the pouch cell 11 under the conditions described in relation to Figure 3. Again, the dashed line shows charging when the magnetic field is rotating and the solid line shows charging when the magnetic field is not rotating (constant). These graphs show that the time it takes to reach a voltage of 4.2V increases in the presence of a rotating magnetic field, so that the first stage of charging, in which current is applied, is maintained for a longer period of time. Since the first stage of charging increases the charge held by the cell more rapidly than the second stage, this means that overall charging is faster when there is a rotating magnetic field through the cell.

[0049] 5 shows the capacity of the pouch cell 11 when charged in the presence of a magnetic field generated by the magnetic field generator 12 when the magnetic field is (i) rotating (indicated by the dashed line) and (ii) not rotating (indicated by the solid line). The pouch cell 11 was charged in two stages. In the first stage, the cell was charged at 0.841 A from 3.4 V to 4.2 V until 4.2 V was reached. Then, in the second stage, the cell was held at a constant voltage while the current decayed to reach capacity.

[0050] As can be seen from Figure 5, in both cycles the cell was charged to 4.2 V, but in the cycle with the magnetic field rotating the capacity of the cell increased by 5%. The charge rate also increased with the magnetic field rotation.

[0051] Figure 6 shows the results of testing the pouch cell 21. The pouch cell 21 has a capacity of 400mAh and dimensions of 5cm x 2cm x 0.5cm. The pouch cell 21 is commercially available via part information: +PL-402248-2C, 3.7V 400mAh -PO 7006 20140726.

[0052] The charge rate of pouch cell 21 is shown in Figure 6 for nine charge cycles. Cycles 1-3 and 7 and 8 were in the presence of a magnetic field rotating at 1170 rpm, cycle 9 was in the presence of a magnetic field rotating at 1000 rpm, and cycles 4-6 were in the presence of a stationary magnetic field.

[0053] As can be seen from FIG. 6, the rate of charge was consistently increased by about 15% with the magnetic field rotation.

[0054] Figure 7 shows the time it takes to charge pouch cell 21 over eight charging cycles in a rotating magnetic field at 1170 rpm, a rotating magnetic field at 1000 rpm, and a static magnetic field (labeled "No Magnetic Field" in the figure). As can be seen from Figure 7, the time it takes to charge the cell is consistently reduced by about 15% in the presence of a rotating magnetic field.

[0055] Figure 8 shows the results of testing the pouch cell 31. The pouch cell 31 has a capacity of 200mAh and dimensions of 2.5cm x 1.7cm x 0.5cm. The pouch cell 31 is commercially available via part information: -PL-651628-2C, 3.7V 210mAh +PO 7994.

[0056] The charge rate of the pouch cell 31 is shown in Figure 8 for two charge cycles. The first cycle was in the presence of a magnetic field rotating at 1160 rpm, and the second cycle was in the presence of a static magnetic field.

[0057] As can be seen from FIG. 8, the rate of charging increased dramatically with the rotation of the magnetic field.

[0058] Figure 9 shows the time it takes to charge the pouch cell 31 during a charge cycle in a rotating magnetic field at 1160 rpm and in a static magnetic field (labeled "No Magnetic Field" in the figure). As can be seen from Figure 9, the time it takes to charge the cell at 4C is reduced by 58% in the presence of a rotating magnetic field.

[0059] Figure 10 shows a configuration used to enhance the performance of a Swagelok type cell 41. A magnetic field generator 42 generates a magnetic field having a direction parallel to the direction shown by the arrow in Figure 10A. The generated magnetic field rotates in the direction shown by the arrow in Figure 10B. The magnetic field passes through the Swagelok cell 41.

[0060] The magnetic field is offset from the axis of rotation to ensure that the magnetic flux within the cell varies over time.

[0061] The magnetic field generator 42 is an electromagnet powered by a power supply 45. A potentiostat 43 is connected to the Swagelok cell 41 and can be used to control the potential across the cell and charge the cell.

[0062] The Swagelok cell 41 is formed from a first electrode and a second electrode separated from each other by an electrolyte and a separator material. The electrodes are substantially parallel and extend across the length and width of the cell. The Swagelok cell 41 has contacts for each of the electrodes that can be connected to a potentiostat, as shown in FIG.

[0063] The Swagelok cell 41 is oriented so that the direction of the magnetic field passes through the cell perpendicular to the direction of the current path between the electrodes. The plane of rotation of the magnetic field is perpendicular to the plane of the electrodes.

[0064] 11 shows the results of testing the Swagelok cell 51. The Swagelok cell 51 has dimensions of 5 cm by 2.5 cm. The Swagelok cell 51 is commercially available as an LMO / graphite Swagelok cell.

[0065] The rates of charging the Swagelok cell 51 are shown in Figure 11 for charging cycles at 1C, 2C and 3C, respectively, in the presence of a rotating magnetic field and in the presence of a static magnetic field (labeled No Magnetic Field in the figure). The rotating magnetic field had a speed of 1100 rpm.

[0066] As can be seen from FIG. 11, the rate of charging increased consistently with the rotation of the magnetic field.

[0067] Figure 12 shows the time it takes to charge the Swagelok cell 51 for charge cycles at 1C, 2C, and 3C, respectively, in the presence of a rotating magnetic field and in the presence of a static magnetic field (labeled No Magnetic Field in the figure). As can be seen from Figure 12, the time it takes to charge the cell 51 is consistently reduced in the presence of a rotating magnetic field.

[0068] Figure 13 shows a configuration used to enhance the performance of a cylindrical cell 61. A magnetic field generator 62 generates a magnetic field having a direction parallel to the direction shown by the arrow in Figure 13B. The generated magnetic field rotates in the direction shown by the arrow in Figure 13C. The magnetic field passes through the cylindrical cell 61.

[0069] A cylindrical cell 61 is formed from a first electrode and a second electrode separated from each other by an electrolyte. The electrodes are spirally wound and extend the length of the cell. The cylindrical cell 61 has contacts for each of the electrodes that can be connected to a potentiostat, as shown in FIG.

[0070] The cylindrical cell 61 is oriented in Figure 13 so that the direction of the magnetic field passes through the cross section of the cylindrical shape perpendicular to the direction between the flat ends of the cylinder. The plane of rotation of the magnetic field is perpendicular to the plane of the end faces of the cylindrical cell.

[0071] As discussed further below, in other embodiments, the cylindrical cells may instead be oriented such that the direction of the magnetic field passes through both ends of the cylindrical cells.

[0072] The magnetic field is offset from the axis of rotation to ensure that the magnetic flux within the cell varies over time.

[0073] The magnetic field generator 62 is an electromagnet powered by a power supply 65. A potentiostat 63 is connected to the cylindrical cell 61 and can be used to control the potential across the cell and charge the cell.

[0074] Figure 14 shows the results of testing a cylindrical cell 71. The cylindrical cell 71 has dimensions of 6.5 cm x 1.8 cm. The cylindrical cell 51 is commercially available as a cylindrical 2190 mAh LG 18650 cell.

[0075] The charging rate of the cylindrical cell 71 is shown in Figure 14 for six charging cycles. Cycles 1 and 2 were in the presence of a magnetic field rotating at 1170 rpm, cycle 5 was in the presence of a magnetic field rotating at 1500 rpm, and cycle 6 was in the presence of a magnetic field rotating at 1200 rpm. Cycles 3 and 4 were in the presence of a stationary magnetic field. In cycles 5 and 6, the cylindrical cell was oriented 90 degrees from the position shown in Figure 13A, with the flat end of the cell facing the magnetic field generator 62.

[0076] As can be seen from FIG. 14, the rate of charging was generally higher in the presence of a rotating magnetic field.

[0077] Figure 15 shows the time it takes to charge the cylindrical cell 71 in the charging cycle of Figure 14. As can be seen from Figure 15, the time it takes to charge the cell 71 was generally shorter in the presence of a rotating magnetic field.

[0078] The principle of improved ion transport resulting in increased charge rate and / or capacity within the electrochemical cell illustrated by the above examples can be explained by a reduction in activation energy as explained below for an example cationic cell.

[0079] The ion velocity ν in the liquid electrolyte is proportional to the drag force F D The electric field force F that drives the motion of the ions increases until it is overcome by E can be explained by the following equation:

number

[0080] The drag force can be approximated from Stokes' law as follows: F D =6πμrν Equation 2 μ Viscosity of liquid r Radius of the ion ν ion velocity

[0081] If the electric force and the drag force are made equal, the terminal velocity of the ion, i.e., its mobility, u i is decided.

number

[0082] Mobility affects conductivity through the following equation: σ i =(|z i |F)c i u i formula 5 c i Molar Cooperation

[0083] Therefore, F E ∝u i ∝σ i formula 6 It is.

[0084] For a polymer electrolyte, the ohmic resistance σ can be described by the following equation:

number

[0085] Therefore, F E ∝u i ∝σ i ∝exp(-ΔG act ) Equation 8 It is.

[0086] The Maxwell-Faraday equations predict that a time-varying magnetic field δB / δt is always accompanied by a spatially varying non-conservative electric field E(r,t), which is written as

number

[0087] The electric field E at a given point is given by the vector electric field force F for a given charge q. E It is defined as: F E =qE Equation 10

[0088] Therefore, the magnetic field affects the activation energy as follows: B ∝ E ∝ F E ∝u i ∝σ i ∝exp(-ΔG act ) Equation 11

[0089] Finally, the conductivity is calculated by the cell resistivity ρ via the equation i , and hence the ohmic potential loss η ohmic is related to.

number

[0090] Thus, in the presence of a magnetic field, a cation-conducting polymer membrane will experience a reduction in ohmic potential loss through a net reduction in the activation energy related to the ion mobility associated with the transport of protons. B ∝ η ohmic formula 13

[0091] The magnetic field can be generated using a permanent magnet or an electromagnet.

[0092] When a permanent magnet is used, in the presence of a magnetic field, the cation-conducting polymer membrane will experience a reduction in ohmic potential loss through a net reduction in activation energy.

number

[0093] Using an electromagnet, in the presence of a magnetic field, a cation-conducting polymer membrane will experience a reduction in ohmic potential loss through a net reduction in activation energy.

number

[0094] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, and which are expressed in particular forms, or where appropriate in terms of means for performing a disclosed function, or in terms of a method or process for obtaining a disclosed result, can be used separately or in any combination of such features to realise the invention in its various forms.

[0095] Although 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 in light of this disclosure. Accordingly, the exemplary embodiments of the present invention set forth above are considered to be illustrative and not limiting. Various modifications to the described embodiments may be made without departing from the spirit and scope of the present invention.

[0096] For the avoidance of doubt, the theoretical explanations provided herein are provided for the purpose of enhancing the understanding of the reader, and the inventors do not wish to be bound by any of these theoretical explanations.

[0097] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0098] Throughout this specification, including the claims which follow, unless otherwise indicated, the words "comprise" and "comprises", "including", and variations such as "comprises", "including", and "comprising" are understood to imply the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of other integers or steps or groups of integers or steps.

[0099] It should be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. As used herein, ranges may be expressed 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, it is understood that the particular value forms another embodiment by using the antecedent "about." The term "about" in connection with numerical values ​​is optional and means, for example, ±10%.

Claims

1. 1. A method of enhancing performance of an electrochemical cell having a first electrode and a second electrode and an electrolyte between the first electrode and the second electrode, the first and second electrodes defining a current path, the method comprising providing a changing magnetic field through the cell.

2. The method of claim 1 , wherein the changing magnetic field has a direction having a component perpendicular to the current path.

3. The method of claim 1 or 2, wherein the changing magnetic field is a rotating magnetic field.

4. The method of claim 1 or 2, wherein the changing magnetic field is an oscillating magnetic field.

5. The method of claim 1 or 2, wherein the varying magnetic field is a pulsed magnetic field.

6. The method according to any one of the preceding claims, wherein the magnetic field rotates about an axis parallel to the current path.

7. The method of any one of claims 1 to 6, wherein the electrochemical cell is a battery.

8. 7. The method of claim 6, wherein the battery is a positive ion battery and the current path is the direction of movement of positive ions.

9. The method according to any one of the preceding claims, wherein the magnetic field is provided by a permanent magnet, or a temporary magnet, or an electromagnet.

10. The method of any one of claims 1 to 9, wherein the electrolyte is organic.

11. A charge accelerator for enhancing the performance of an electrochemical cell, the charge accelerator being configured to carry out the method according to any one of claims 1 to 10.

12. A method of charging an electrochemical cell, comprising the step of providing a current or voltage to the cell from a power source whilst carrying out a method according to any one of claims 1 to 10.

13. A method of discharging an electrochemical cell, comprising the step of extracting a current or voltage from the cell whilst carrying out a method according to any one of claims 1 to 10.

14. A method of enhancing the capacity of an electrochemical cell, comprising forming the electrochemical cell whilst carrying out the method according to any one of claims 1 to 10.

15. A method for enhancing the capacity of an electrochemical cell, comprising the step of charging or discharging the electrochemical cell whilst carrying out a method according to any one of claims 1 to 10.

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