Systems and methods for operating rechargeable electrochemical cells or batteries

Abstract

Electrochemical cell management system comprising an electrochemical cell and at least one controller configured to control the cell such that, for at least a portion of a charge cycle, the cell is charged at a charge rate or charge current that is lower than the discharge rate or discharge current of at least a portion of a previous discharge cycle. Electrochemical cell management method. Electrochemical cell management system comprising an electrochemical cell and at least one controller configured to induce discharge of the cell before and / or after a charging step of the cell. Electrochemical cell management method. Electrochemical cell management system comprising an electrochemical cell and at least one controller configured to monitor at least one characteristic of the cell and induce discharge and / or control the charge rate or charge current of the cell based on at least one characteristic of the cell.

Description

[Technical Field]

[0001] This invention relates to the charging and discharging management of electrochemical cells and related systems. [Background technology]

[0002] Traditionally, batteries have been unable to effectively compete with established power sources such as internal combustion engines in various industries, including automobiles. One reason for this is that battery users were dissatisfied with the lifespan and performance of conventionally available batteries. [Overview of the project]

[0003] Disclosed herein are embodiments relating to charge / discharge control and related systems for electrochemical cells. The subject matter of the present invention may, in some cases, include interrelated products, alternative solutions to specific problems, and / or multiple different applications of one or more systems and / or articles.

[0004] Some embodiments are directed to an electrochemical cell management system comprising an electrochemical cell and at least one controller configured to control the cell such that, for at least a portion of a charging cycle, the cell is charged at a charging rate or charging current lower than that of at least a portion of the previous discharge cycle.

[0005] Some embodiments are directed toward an electrochemical cell management system comprising: an electrochemical cell; and at least one controller configured to monitor at least one characteristic of the cell, wherein the at least one characteristic includes at least a portion of the cell's discharge history and at least one of the cell's morphological characteristics, and the controller induces the discharge of the cell and / or controls the charging rate or charging current of the cell based on the at least one characteristic of the cell.

[0006] Some embodiments are directed to an electrochemical cell management system comprising an electrochemical cell and at least one controller configured to induce (or trigger) discharge of the cell before and / or after a charging process of the cell.

[0007] Further embodiments are directed to an electrochemical cell management method. The method may include controlling an electrochemical cell such that, for at least a portion of a charging cycle, the cell is charged at a charging rate or charging current lower than at least a portion of a discharge rate or discharge current of a previous discharge cycle.

[0008] Further embodiments are directed to an electrochemical cell management method. The method may include inducing discharge of an electrochemical cell before and / or after a charging process of the electrochemical cell.

[0009] Some embodiments are directed to an electrochemical cell management method. The method may include monitoring at least one characteristic of the cell, the at least one characteristic may include at least a portion of a discharge history of the cell and at least one of at least one morphological characteristic of the cell, and inducing discharge of the cell and / or controlling a charging rate or charging current of the cell based on the at least one characteristic of the cell.

[0010] Other advantages and novel features of the present invention will become apparent from the following detailed description of various non-limiting embodiments of the present invention when considered in conjunction with the accompanying drawings. In case the present specification includes disclosures that conflict with and / or are inconsistent with the documents incorporated by reference, the present specification shall prevail. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Non-limiting embodiments of the present invention are described by reference to the accompanying drawings, which are schematic and not intended to be drawn to any particular scale. In the drawings, each identical or substantially identical component shown is usually represented by a single number. For clarity, not all components are necessarily labeled in all drawings, and the drawings are all components of each embodiment of the present invention shown where it is not necessary for those skilled in the art to understand the invention. In the drawings: [Figure 1A] This is a block diagram illustrating a typical electrochemical cell management system according to several embodiments. [Figure 1B] This is a current-time graph showing a typical charging scheme for a representative electrochemical cell management system according to several embodiments. [Figure 1C] This is a current-time graph showing a typical charging scheme for a representative electrochemical cell management system according to several embodiments. [Figure 1D] This is a current-time graph showing a typical charging scheme for a representative electrochemical cell management system according to several embodiments. [Figure 1E] This is a circuit diagram illustrating a typical simplified electrochemical cell model based on several embodiments. [Figure 1F] This is a block diagram illustrating a typical battery management system according to several embodiments. [Figure 2] This is a block diagram illustrating a typical battery pack according to several embodiments. [Figure 3A] This is a block diagram illustrating a typical battery management system according to several embodiments. [Figure 3B] This block diagram shows typical cell sets and corresponding components according to several embodiments. [Figure 3C] This is a schematic cross-sectional diagram illustrating the application of anisotropic forces to one or more electrochemical cells according to several embodiments. [Figure 3D] These are schematic cross-sectional views of electrochemical cells according to several embodiments. [Figure 4A] This flowchart shows a typical process for controlling the charging speed or charging current of the above-mentioned cell according to several embodiments. [Figure 4B] This flowchart shows further representative processes for controlling the charging speed or charging current of the above-mentioned cell according to several embodiments. [Figure 4C] This flowchart shows typical steps for inducing the discharge of the above-mentioned cell according to several embodiments. [Figure 4D] This flowchart shows further representative steps for inducing the discharge of the above-mentioned cell according to several embodiments. [Figure 5A] This flowchart shows typical processes for monitoring the characteristics of the cell, inducing discharge, or controlling the charging speed or charging current of the cell, according to several embodiments. [Figure 5B] This flowchart shows some typical steps for monitoring the cell characteristics, inducing discharge, or controlling the charging speed or charging current of the cell, according to several embodiments. [Figure 6A] This flowchart shows a typical process for discharging the above set of cells of a battery according to several embodiments. [Figure 6B] This flowchart shows a further representative process for discharging the above set of cells of a battery according to several embodiments. [Figure 6C] This flowchart shows a typical process for controlling a battery pack according to several embodiments. [Figure 6D] A flowchart shows further representative processes for controlling a battery pack according to several embodiments. [Figure 7A] This chart shows exemplary discharge profiles according to several embodiments. [Figure 7B] This chart shows exemplary complete discharge profiles for several embodiments. [Figure 7C]This chart shows exemplary battery cycle life in several embodiments. [Figure 8] This is a block diagram showing typical computing systems that may be used to implement a particular configuration. [Modes for carrying out the invention]

[0012] The inventors recognize and understand that conventional techniques for managing and operating rechargeable electrochemical cells have resulted in previously inferior lifespan and performance for the cells (and batteries in which they may be included). For example, the cells have suffered from short cycle life (e.g., a low number of full charge and discharge cycles before the capacity drops to 80% or less of the original capacity, which typically happens at some point after sufficient use of the cells), especially when the charge and discharge rates are similar or when the charge rate is higher than the discharge rate. For example, many users of the cells in batteries desire that the batteries have nearly identical charge and discharge rates (e.g., 4 hours to charge, 4 hours to discharge), and battery manufacturers have provided batteries and battery management systems that offer such nearly identical rates. Also, many users have desired to charge batteries at a rate higher than the rate at which they discharge (e.g., 30 minutes to charge, 4 hours to discharge) for various reasons, such as to alleviate the inconvenience of waiting for the battery to be charged before use.

[0013] In this specification, the term “full charge cycle” is generally used to refer to a period during which approximately 100% of the recharge capacity of the cell is charged, and the term “full discharge cycle” is generally used to refer to a period during which approximately 100% of the discharge capacity (which may differ from its recharge capacity) of the cell is discharged. On the other hand, in this specification, the term “charge process” is generally used to refer to a continuous period during which charging occurs without discharging, and the term “discharge process” is generally used to refer to a continuous period during which discharging occurs without charging.

[0014] The term "charge cycle" is generally used to refer to the period during which the above cell is charged, and does not necessarily have to be a complete charge cycle. The term "discharge cycle" is generally used to refer to the period during which the above cell is discharged, and it does not necessarily have to be a complete discharge cycle. The term "previous discharge cycle" is generally used to refer to the period during which the above cell was discharged or is currently being discharged. For example, this "previous" discharge cycle may be completed or still in progress, and does not necessarily have to refer to the most recently completed discharge process that totals approximately 100% of the cell's discharge capacity. If a complete discharge cycle has not been performed, the previous discharge cycle may refer to the last completed discharge process.

[0015] The term "capacity" is generally used to refer to the amount of charge that the cell can supply at a given or rated voltage, and is often measured in ampere-hours (milliampere-hours or mAh, etc.). In some embodiments, capacity may be the mAh that the cell can hold at a given time (which may vary over multiple charge or discharge cycles), the mAh remaining in the cell at a given time, or the mAh required for the cell to be fully recharged.

[0016] The inventors recognize and understand that the cycle life of the cell (and battery containing the cell), and consequently the life and performance of the cell (and battery), can be significantly improved by employing a high ratio of discharge rate to charge rate. Furthermore, the inventors recognize and understand that these ratios can be employed by providing the cell and / or battery management system that controls the cell to provide such a ratio.

[0017] For example, some embodiments are directed to a cell management system that controls the cell so that for at least a portion of a charging cycle, the cell is charged at a charging rate or current lower than the discharge rate or current of at least a portion of the previous discharge cycle. As another example, some embodiments are directed to a cell management system that monitors at least one characteristic of the cell (such as a portion of the cell's discharge history or a morphological characteristic of the cell) and induces the discharge of the cell or controls the charging rate or current based on the characteristic. As yet another example, some embodiments are directed to a cell management system that induces the discharge of the cell immediately before and / or immediately after (or at some earlier time) the charging process of the cell while the cell is connected to a charging device.

[0018] In some embodiments, inducing the discharge of the cell may include discharging the cell in response to a command from a controller. In some embodiments, the induced discharge may be at a rate higher than the average discharge rate in the cell's discharge history. In some embodiments, the induced discharge may include discharging the cell without supplying power to a load to perform a function, which may be done for the purpose of changing the overall average discharge rate of the cell and / or the average of the current charge / discharge cycle. In some embodiments, the induced discharge may be performed during a charge cycle that includes multiple charge steps, as shown in Figures 1B to 1D.

[0019] Some embodiments, such as those having multiple cells, are directed towards battery management systems that multiplex the cells so that all of them can be charged at once (or multiple cells can be discharged simultaneously) and can be discharged individually or in smaller sets. This can result in an actual charge-to-discharge rate ratio of the cells that improves cycle life while providing the desired or required output speed for a particular load or application. Furthermore, the inventors recognize and appreciate that discharging only some, rather than all, of the cells at once with a homogeneous current distribution may also improve cycle life.

[0020] For example, in a battery having four of the above cells, each cell can be discharged at 0.5 amps for 3 hours, and then all four cells can be charged at 0.5 amps for 12 hours. In this configuration, the actual ratio of discharge rate to charge rate is 4:1, but from the user's perspective, the ratio is 1:1 because each cell discharges for 3 hours (total discharge time of 12 hours). The inventors recognize and understand that such a battery management system can actually improve the battery's cycle life while providing what the user wants or needs from the battery. In some embodiments, the functionality that provides these two advantages may be invisible to the user and may be incorporated into the cell block and / or the battery itself.

[0021] The inventors recognize and understand that, compared to prior art which relied on very simple selection processes such as "round robin" or taking into account the number of previous discharge cycles, the battery cycle life can be further improved by monitoring the cell cycle and various characteristics (such as the connection period between the load and the cell currently connected to the load, or a more complex function that takes into account multiple parameters), and based on this monitoring, selecting when to discharge the cell.

[0022] Figure 1A shows a typical cell management system 100. In some embodiments, the typical system 100 may include a controller (e.g., 114) and an electrochemical cell (e.g., 121A). In some embodiments, the cell 121A may exist alone. In other embodiments, there may be further cells (e.g., any of the cells 121B and 121C in Figure 1A) and / or further sets of cells (e.g., any of the cell sets 122 in Figure 1A) (e.g., to form a battery 120). Optionally, the system 100 may include one or more sensors (e.g., 116). Although only a single controller 114 and a single sensor 116 are shown in Figure 1A, it should be understood that any preferred number of these components may be used. Any of a number of different embodiments may be adopted.

[0023] According to some embodiments, cell 121A may include at least one lithium metal electrode active material (or active material). Furthermore, each set of cells (e.g., cell set 121) may include one or more cells (e.g., 121A to 121C). In some embodiments, each set of cells may comprise a single cell. Alternatively, each set of cells may comprise multiple cells to form a cell "block," or multiple sets of cells may come together to form a cell block. Furthermore, each cell (a battery, all batteries in a battery pack, or within a set of cells) or set of cells may utilize the same electrochemistry. That is, in some embodiments, each cell may utilize the same anode active material and the same cathode active material.

[0024] In some embodiments, such as those having multiple cells, a multiplexing switch device (not shown in Figure 1A) may be included, as described in relation to Figure 1B below, and an array of switches may be included, as further described in relation to Figures 3A and 3B below. Furthermore, the multiplexing switch device may be connected to each set of cells and / or to each cell individually. In some embodiments, a controller such as 114 may use the multiplexing switch device to selectively discharge the set of cells.

[0025] In some embodiments, the controller (e.g., 114) may include one or more processors, which may be of any complexity appropriate for the application. Alternatively or additionally, the controller may include analog circuits and / or logic devices that are no more complex than the processors or microprocessors.

[0026] In some embodiments, the controller may control the cell such that for at least a portion of the cell's charging cycles, the cell is charged at a charging rate or current lower than the discharge rate or current of at least a portion of the previous discharge cycle. For example, the controller may cause the cell to be charged at an average of at least twice the discharge rate or current used for a certain percentage of the cell's discharge capacity (e.g., somewhere between 1% and 100% of the discharge capacity) relative to a certain percentage of the cell's recharge capacity (e.g., somewhere between 1% and 100% of the recharge capacity) (i.e., the charging rate or current is half the rate of the discharge rate or current). Alternatively or additionally, the controller may cause the cell to be charged at a charging rate or current at at least four times lower than the discharge rate (e.g., as a result of this control, over the last discharge / charge cycle, the cell is charged for a certain percentage of its recharge capacity at 1 / 4 the rate at which it was discharged for a certain percentage of the cell's discharge capacity). The inventors recognize and understand that such a ratio of charge rate to discharge rate can improve the performance and cycle life of the above-mentioned cell.

[0027] In some embodiments, controlling the cell may include controlling the timing and method of starting and stopping charging and discharging, inducing discharge, and increasing or decreasing the rate or current of charging or discharging. For example, controlling the charging or discharging of the cell may include starting charging or discharging, stopping charging or discharging, and increasing or decreasing the rate or current of charging or discharging, respectively.

[0028] In some embodiments, the cell is charged such that, over a period of time during which at least 5% (or at least 1%, or at least 10%, or at least 15%, or at least 25%, or somewhere in between) of the cell's capacity is charged, the average charge rate or average charge current is lower than the average discharge rate or average charge current used to discharge at least 5% (or at least 10%, or at least 15%, or at least 25%, or somewhere in between) of the cell's capacity during the previous discharge cycle, which may be the immediately preceding discharge cycle or a previous discharge cycle.

[0029] In some embodiments, the charging step is performed such that, for at least 5% (or at least 10%, at least 25%, at least 50%, or at least 75%) of the capacity of the cell or battery, the average charging rate and / or charging current is less than 50% (or less than 35%, or less than 25%) of the average discharge rate and / or average discharge current that at least 5% (or at least 10%, at least 25%, at least 50%, or at least 75%) of the capacity of the cell or battery discharged during the previous discharge step.

[0030] In some embodiments, the average discharge rate or average discharge current during the preceding discharge cycle may be equal to or less than the average charge rate or average charge current during the charge cycle, and the average discharge rate or average discharge current when at least 5% of the cell's discharge capacity is discharged during the preceding discharge cycle may be at least twice (or four times) higher than the average charge rate or average charge current during the charge cycle. The inventors recognize and understand that, as long as the average discharge rate or average discharge current is sufficiently (e.g., at least twice, three times, or four times) higher than the average charge rate or average charge current during the discharge of at least a portion (e.g., 5%) of the cell's discharge capacity during the previous discharge cycle, improvements such as improved cell cycle life can still be achieved even if the average discharge rate of the cell is the same as or slower than the charge rate.

[0031] As used herein, when the cell is charged at a plurality of different rates over a predetermined period (e.g., over part of the charging process, over the entire charging process, or over a series of charging processes), the average charging rate over that predetermined period is calculated as follows.

Equation

Equation

[0032] As used herein, when the cell is discharged at a plurality of different rates over a predetermined period (e.g., over a predetermined charging process or a series of charging processes), the average discharge rate during that predetermined period is calculated as follows.

Equation

number

[0033] The inventors recognize and understand that determining the charge rate, which can improve the performance and cycle life of the cells, such as lithium metal cells, involves a number of factors, which may include the discharge rate, the cell impedance, and / or the state of health (SOH) of the cells. In some embodiments, the controller can recognize these factors so that it can measure parameters or characteristics (e.g., via sensor 116) that can be used to determine each of them. The controller may directly or indirectly measure the charge and discharge currents, added or removed coulombs, the cell impedance (capacitive and resistive), and / or the pressure, size, and / or thickness of the cells.

[0034] In some embodiments, the controller may monitor such characteristics of the cell. For example, the characteristics may include at least a portion of the cell's discharge history. Alternatively or additionally, the characteristics may include at least one morphological characteristic of the cell. The controller may monitor any of these using sensors 116 such as a pressure sensor, a gauge for measuring thickness, a sensor for measuring or determining surface roughness and / or pits (such as pits in the anode), and / or a memory for storing the cell's charge / discharge history. For example, a pressure sensor may be included for measuring uniaxial pressure and / or gas pressure (such as to determine whether the cell is generating an excessive amount of gas). Alternatively or additionally, a gauge for measuring the thickness of the cell may be included, and the controller may determine and monitor at least one rate of increase of the thickness.

[0035] In some embodiments, the controller may use this information, such as characteristics, to determine the charging method and / or speed to use, which may include controlling the speed or other parameters as described herein. For example, the overall charging method may be similar to that shown in Figure 1B, where the cell is discharged for time DT and charged for time CT. As shown in Figure 1B, the cell is discharged for a short time, then fully charged with a current lower than that for discharge, then discharged for a short time and topped back on charge.

[0036] As another example, the overall charging scheme may be similar to that shown in Figure 1C, where the cell is discharged for time DT, charged for time CT with a lower current than during discharge, discharged again for time DT, charged again for time CT, and discharged again for time DT. In some embodiments, CT may correspond to more than just half of the total recharge capacity of the cell, and CT may be a relatively short time determined by the state of overheardness (SOH) of the cell.

[0037] In some embodiments, the controller may induce a discharge of the cell, such as one of the discharges shown in Figures 1B to 1D. For example, the controller may induce a discharge of the cell immediately before the start of the charging process of the cell, in the manner shown in Figures 1B to 1C. In some embodiments, the controller may cause such an induced discharge or one of those described herein based on the characteristics of the cell. Alternatively, the controller may perform or induce any of these induced discharges based on other criteria, as described herein. In some embodiments, the cell may remain connected to the charging device during both the induced discharge and the ambient charging process.

[0038] The inventors recognize and understand that inducing discharge at the times described herein can improve the performance and cycle life of the cell by bringing the ratio of discharge to charge rate or charge current closer to a desired asymmetric range, such as 2:1 or 4:1. For example, if the cell is discharged at a lower rate or current than it is charged, such induced discharge may be performed at a much higher rate or current to improve the ratio, particularly during a portion of the charge / discharge cycle. In some embodiments, the controller may induce a discharge of the cell at a first rate or first current, through at least a threshold capacity of the cell (such as at least 5%, at least 10%, or at least 15% of the cell's discharge or recharge capacity), before the start of a charging process of the cell that charges the cell at a slower rate or current than the first rate or first current (e.g., immediately before or less than 10 minutes before). In some embodiments, the controller may induce discharge at a rate or current higher than the average discharge rate or average discharge current of the previous (most recent) discharge cycle and / or discharge process, or at a rate higher than the average charge rate or average charge current of the previous (most recent) charge cycle and / or charge process.

[0039] Alternatively or additionally, the controller may induce a discharge of the cell during the discharge cycle and / or discharge process (e.g., at termination). In some embodiments, the controller may induce such a discharge at a higher rate or current than existing discharges or the average discharge of the previous discharge cycle. For example, if the average discharge current of the most recent discharge cycle was 100 mA, the discharge may be induced at 400 mA. Other examples are shown in Tables 1 to 4 below.

[0040] The controller may, alternatively or additionally, induce discharge at the end of the charging cycle and / or the discharge process of the cell, in a form as shown in Figure 1C. In some embodiments, inducing discharge at the end of the cycle may include inducing discharge within the last 5% (or 10% or 15%) of the cycle.

[0041] The inventors have recognized and understood that in some or all of the situations described herein, inducing the discharge of the cell can reduce physical damage to the cell, such as the formation and extension of pits (e.g., at the anode of the cell), and can even smooth and reverse some previous damage to the cell.

[0042] The overall charging scheme may look similar to Figure 1D, which, as a further example, shows the above cell being charged first during time PCT, then discharged during CT, and finally fully charged during CT. The inventors recognize and understand that it is not advantageous to start from the discharge cycle and / or discharge process if the above cell is determined to be fully discharged, as may be the case with the above cell in Figure 1D.

[0043] In some embodiments, the controller may consider any of several factors when determining the state of charge (SOC) and state of health (SOH) of the cell. For example, with respect to the cell impedance, the cell model can be simplified as shown in Figure 1E, which shows a parallel combination of a resistor (RP) and a capacitor (C1) and a series resistor (RS). Impedance measurement may have two components: a real component and an imaginary component. The real component can simply be the DC resistance R = RS + RP. In this case, the imaginary (or invalid) component is XC: XC = 1 / (2πfc) (Here, f is the frequency and c is the capacitance.) This is inversely proportional to the frequency. The impedance (Z) can be calculated at any frequency, and the phase angle is given by the following formula:

number

[0044] The inventors also recognized and understood that the charge / discharge cycle and / or pulses of the charge / discharge process should not be applied at a speed faster than approximately two or three times the RC time constant, because at faster speeds, a large portion of the energy may not be effectively used for charging or discharging the cell. Rather, it may be mostly reactive, with most of the energy being returned by capacitance or dissipated by resistance.

[0045] The inventors further recognize and understand that the cell grows and shrinks in thickness with each cycle, and that a portion of the growth is retained with each cycle. This growth and shrinkage can be measured by directly monitoring the pressure and / or size changes of the cell. These are further inputs that can be used in determining the State of Charge (SOC) and State of Health (SOH), and can also be used in determining how to charge the cell.

[0046] In some embodiments, the controller may control the charging of the cell based on the characteristics of the cell. For example, if the cell has a discharge cycle or history in which it discharged at a certain discharge rate or discharge current (e.g., 300 mA) for at least a portion of the previous discharge cycle, the cell may be controlled to charge at a lower rate or current (e.g., 150 mA or 75 mA) for at least a portion of the charging cycle.

[0047] In some embodiments, including induced discharge, the controller may control the cell to charge for at least a portion of the charge cycle (e.g., 5% of the cycle) at a charge rate or charge current lower than the discharge rate or discharge current of at least a portion of the previous discharge cycle that did not include (i.e., did not include) induced discharge.

[0048] As another example, the controller may terminate the use of the cell if the applied anisotropic pressure falls below a threshold, which may indicate that the pressure application system (examples of which are described in more detail below) is damaged. For example, in some embodiments, such a threshold may be 1% to 50% of the nominal applied anisotropic pressure. Alternatively or additionally, the controller may terminate the use of the cell if the pressure is too high or the thickness is increasing faster than a threshold. For example, in some embodiments, such a threshold rate may be 1% to 3% or more of the thickness increase per cycle.

[0049] Figure 1F shows a typical battery management system 100. In some embodiments, such as embodiments having multiple cells, the typical system 100 may include a multiplexing switch device (e.g., 112), a controller (e.g., 114), one or more sensors (e.g., 116), and one or more batteries (e.g., 120, 130, 140, 150, etc.). Although only a single multiplexing switch device 112, a controller 114, a sensor 116, and four batteries 120-150 are shown in Figure 1F, it should be understood that any preferred number of these components may be used. Any of a number of different embodiments may be employed. Furthermore, although singular labels are used to refer to multiplexing switch devices in this specification, it should be understood that the components used for multiplexing and switching described herein may be distributed among any preferred number of devices (e.g., switches).

[0050] According to some embodiments, a battery or cell may include at least one lithium metal cell. Furthermore, each battery or cell (e.g., 120-150) may include one or more cell sets (e.g., 121-124, 131-132, 141-142, 151-152, etc.), also called sets of cells. In some embodiments, two or more sets of cells are included in each battery, such as 121-122. Furthermore, each of the above sets of cells (e.g., cell set 121) may include one or more cells (e.g., 121A-121C). In some embodiments, each of the above sets of cells may have a single cell. Alternatively, each set of cells may include multiple cells and form a cell "block", or multiple sets of cells may together form the cell block. Furthermore, each cell (any of the batteries, all batteries in a battery pack, or within the above sets of cells) or the above sets of cells may utilize the same electrochemistry. In other words, in some embodiments, each cell may utilize the same anode active material and the same cathode active material.

[0051] In some embodiments, the multiplexing switch device (e.g., 112) may include an array of switches, as further described in relation to Figures 3A and 3B below. Furthermore, the multiplexing switch device may be connected to each set of the cells and / or to each cell individually. In some embodiments, a controller such as 114 may use the multiplexing switch device to selectively discharge the cells or sets of cells based on at least one criterion.

[0052] For example, the criteria may include the order in which the set of cells are discharged, such as a predefined numbering or sequence related to the set of cells (e.g., starting from the first set, switching through each set to the last set, and then starting again from the first set), and may also include an order based on the set of cells having some other indicator indicating the next highest voltage or next strongest. The inventors recognize and understand that by using an order, in particular a predefined numbering, the complexity of the operations performed by the system (e.g., a controller other than a microprocessor) can be reduced and may be usable by systems with a wider array.

[0053] Alternatively or additionally, the criterion may be context-dependent, for example, by considering the duration of the connection between the load and the set of cells currently connected to the load (which may be at least 0.01 seconds in some embodiments), the delivery discharge capacity in the connection, and any one or more values ​​of a function having one or more parameters. In some embodiments, the criterion may not include the number of preceding discharge cycles of the set of cells.

[0054] In some embodiments, the function may have parameters such as one or more of the following: the capacity accumulated across several connections between the load and the set of cells; the discharge capacity delivered at the connection; the current of the set of cells; the voltage of the set of cells and / or at least one other set of cells; the discharge termination voltage (or discharge cutoff voltage) of the set of cells; the power of the set of cells; the energy of the set of cells; the number of charge or discharge cycles of the set of cells; the impedance of the set of cells; the rate of voltage fading of the set of cells in connection; the temperature of the set of cells; and the pressure of the set of cells (e.g., the pressure from the physical housing of the cells to the cells, which can indicate the capacity of the cells, and will be discussed further below). According to some embodiments, the discharge capacity delivered at a single connection may be in the range of 0.01% of the nominal capacity to 100% (e.g., 95%) of the set nominal capacity.

[0055] In some embodiments, a sensor (e.g., 116) may measure either a reference and / or a parameter of a function. For example, the sensor may include a current sensor that measures the current in amperes of a given set of the cells. It should be understood that the reference may be singular or plural, may be related to the set of cells currently discharging, and / or may determine the next set of cells.

[0056] In some embodiments, the controller (e.g., 114) may include one or more processors, which may be of any complexity appropriate for the application. For example, evaluating the functionality of a standard in some embodiments may depend on microprocessors that form part or all of the controller.

[0057] In some embodiments, the controller may use a multiplexing switch to selectively discharge and charge the set of cells at different, programmable speeds. For example, the controller may use a multiplexing switch to selectively discharge the set of cells at a first speed at least twice as high as a second speed at which the set of cells are charged (i.e., discharging is twice as fast as charging). Alternatively or additionally, the first discharge speed may be at least four times higher than the second speed at which the set of cells are charged (i.e., discharging is four times as fast as charging). The inventors recognize and appreciate that such a ratio of discharge speed to charge speed can improve the performance and cycle life of the cells.

[0058] According to some embodiments, the controller may temporally overlap the discharge of a set of the cells. For example, another set of the cells may begin discharging before a given set of cells has stopped discharging. In some embodiments, the controller may continue to supply power from the set of cells during the switching between different sets. The inventors recognize and understand that this temporal overlap of discharge and power continuity can maintain the power requirements of the load even during the transition between different sets of the cells, thereby potentially improving the cycle life of the cells compared to the prior art. Thus, multiple cells may discharge simultaneously during such overlap. Furthermore, such overlap can provide smoother voltage transitions than were possible in the prior art.

[0059] In some embodiments, the load may be at least one component of the vehicle. The vehicle may be any suitable vehicle adapted for travel on land, sea, and / or air. For example, the vehicle may be a car, truck, motorcycle, boat, helicopter, airplane, and / or any other suitable type of vehicle.

[0060] Alternatively or additionally, the controller may use a multiplexing switch (e.g., 112) to connect the set of cells to the load in a topology adopted or required by the load.

[0061] In some embodiments, the controller may use a multiplexing switch (e.g., 112) to isolate a single set of cells for discharge while other sets of cells are not discharged. Alternatively or additionally, a single cell may be isolated at once. For example, the controller may use a multiplexing switch to isolate a single set of cells or a single cell for discharge while other sets of cells are not discharged. In some embodiments, for a given cycle, each cell may be discharged once before any of the cells are discharged twice (e.g., sequential discharge is used, but is not limited to such embodiments).

[0062] With regard to charging, in some embodiments, the controller may use a multiplexing switch to charge the set of cells and / or the cells within the set in parallel. For example, the cell block, battery, or all the cells within the battery may be charged in parallel at a rate of one-quarter of the discharge rate.

[0063] Figure 2 shows a typical battery pack 210. In some embodiments, a typical battery pack 210 may include a switching control system (e.g., 218) and one or more batteries (e.g., 120, 130, 140, 150, etc.). Although Figure 2 shows only a single switching control system 218 and four batteries 120-150, it should be understood that any suitable number of these components may be used. Any of a number of different embodiments may be employed. Furthermore, although singular labels are used to refer to switching control systems in this specification, it should be understood that the components used for control and switching described herein may be distributed across any suitable number of devices (e.g., switches, controllers, etc.).

[0064] In some embodiments, the switching control system (e.g., 218) may include an array of switches, as further described in relation to Figures 3A and 3B below, and may include a controller. Furthermore, the switching control system may be connected individually to each set of cells and / or to each cell of the battery, as described with respect to Figure 1F above. In some embodiments, the switching control system may be incorporated into the battery pack. Furthermore, the switching control system may control the switches (e.g., in a switch array) to discharge the set of cells sequentially, such as in a predetermined order related to the set of cells. Alternatively or additionally, the switching control system may control the switches to discharge the set of cells based on one or more of the following: the duration of the connection between the load and the set of cells currently connected to the load (which may be at least 0.01 seconds in some embodiments), the delivery discharge capacity in the connection, and the value of a function. In some embodiments, the basis for control may not include the number of preceding discharge cycles of the set of cells.

[0065] According to some embodiments, the switching control system may perform any number of other functions, such as the functions of the controller described in relation to Figures 1A and 1F above.

[0066] It should be understood that either the components of the typical system 100 or the typical battery pack 210 may be implemented using any suitable combination of hardware and / or software components. Thus, various components can be considered controllers that can employ any suitable collection of hardware and / or software components to perform the described functions.

[0067] Figure 3A shows a typical battery management system 300. In some embodiments, the typical system 300 may include any preferred number of multicell blocks (e.g., 321-325), a battery cell block arrangement and balance switch configuration (e.g., 326), a battery management microcontroller (e.g., 327), a battery system interface (e.g., 328), battery power terminals (e.g., 329), and sensors (e.g., 360). The multicell blocks may be connected to the battery cell block arrangement and balance switch configuration. The multicell blocks may also be connected to the battery management microcontroller.

[0068] In some embodiments, the battery cell block arrangement and balance switch configuration may include switch multiplexing, which may connect the cell blocks (e.g., 321-325) in series, parallel, series / parallel, or any other suitable topology necessary to meet the voltage and current requirements of a given application or load.

[0069] According to some embodiments, the battery management microcontroller may monitor and control the charging and discharging of the battery management system to ensure the safe operation of the system and its components. Furthermore, the battery management microcontroller may communicate not only with users (e.g., consumers who use the system to power a load) but also with any suitable internal production, calibration, and test equipment. For example, the battery management microcontroller may be connected to a battery system interface (e.g., 328), which may provide the necessary interfaces for the battery management microcontroller to communicate with internal production, calibration, and test equipment as well as users, and any other suitable entities.

[0070] In some embodiments, the sensor may be connected to the battery cell block arrangement and balance switch configuration, the battery management microcontroller, and / or the battery power terminals, and may measure attributes of the multicell block and / or any other elements of the system. For example, the sensor may measure attributes of the multicell block that form either a reference and / or a parameter of a function, as described above. For example, the sensor may include a current sensor that measures the current in amperes for a given set of cells.

[0071] The battery cell block arrangement and balance switch configuration 326, the battery management microcontroller 327, the battery system interface 328, and the sensor 360 are presented in the singular form, and although only five multi-cell blocks 321-325 are shown in Figure 3A, it should be understood that any suitable number of these components may be used, and they may represent multiple components. Any of a number of different embodiments may be employed. In fact, although singular labels are used in this specification to refer to the battery cell block arrangement and balance switch configuration, it should be understood that the components used in the arrangement and balance switch described herein may be distributed across any suitable number of devices (e.g., switches).

[0072] Figure 3B shows a typical cell set and its corresponding components. In some embodiments, the typical cell set may include any suitable number of the cells (e.g., 321A-321C) and may constitute a multi-cell block as described above. Furthermore, the typical cell set may include a cell multiplexing switch (e.g., 326A1), the cell balance switch and resistor (e.g., 326A2), a cell block microcontroller (e.g., 327A), a battery management microcontroller interface (e.g., 328A), a sensor (e.g., 360A), and an input / output bus for the cell set (e.g., 321IO). In some embodiments, the cells may be connected to the cell balance switch and resistor, which may be connected to the cell multiplexing switch.

[0073] In some embodiments, each cell (e.g., each of 321A to 321C) may be connected to the array of cell multiplexing switches, which may connect or disconnect a given cell from an input / output bus (e.g., 321IO), and may connect or disconnect a given cell to a balance resistor (e.g., one of the resistors in 326A2) that shares a balance bus with the other cells. Furthermore, in discharge mode, one cell (e.g., 321A) may be connected to an input / output bus and disconnected from a balance resistor. The remaining cells (e.g., 321B to 321C) may be disconnected from the input / output bus and connected to the corresponding balance resistors. Furthermore, in charge mode according to some embodiments, all cells (e.g., 321A to 321C) may be connected to an input / output bus and disconnected from balance resistor 326A2.

[0074] According to some embodiments, the cell block microcontroller (e.g., 327A) may generate switching waveforms to ensure that the overlap and deadband requirements for switching are appropriate for the application or load. Furthermore, the cell block microcontroller may determine the state required by the application or load by monitoring the voltage and current of the cell block and by receiving communications from a battery management microcontroller (e.g., 327 in Figure 3A) to which the cell block microcontroller may be connected via a battery management microcontroller interface.

[0075] Figure 3C is an exemplary cross-sectional schematic diagram of an electrochemical system in which an anisotropic force is applied to an electrochemical cell (e.g., 321A) according to a set of embodiments. In this specification, the term “electrochemical cell” is used generally to refer to an anode, cathode, and electrolyte configured to participate in an electrochemical reaction for generating electricity. The electrochemical cell may be rechargeable or non-rechargeable.

[0076] In Figure 3C, the system may include an electrochemical cell 321A and, in some embodiments, a pressure distributor 334 containing a fluid associated with the electrochemical cell 321A. The pressure distributor 334 may be configured to apply anisotropic forces to the components of the electrochemical cell 321A via the pressure distributor 334. For example, in a series of embodiments illustrated in Figure 3C, a pressure transmitter 336 may be configured to apply an anisotropic force to the pressure distributor 334, thereby applying an anisotropic force to at least one component of the electrochemical cell 321A (e.g., an electrode). The system may also include a substrate 332 on which the electrochemical cell is placed. The substrate 332 may include, for example, a table surface, the surface of a container housing the electrochemical cell 321A, or any other suitable surface.

[0077] The pressure distributor 334 can be associated with the electrochemical cell 321A in various preferred configurations to manufacture the systems and methods of the present invention described herein. As used herein, the pressure distributor is associated with the electrochemical cell when at least a portion of the force applied to and / or through the pressure distributor can be transmitted to the components of the electrochemical cell. For example, in some embodiments, the pressure distributor is associated with the electrochemical cell when the pressure distributor is in direct contact with the electrochemical cell or its components. Generally, a first article and a second article are in direct contact when the first article and the second article are in direct contact. For example, in Figure 3C, the pressure distributor 334 and the electrochemical cell 321A are in direct contact.

[0078] In some embodiments, a pressure distributor is associated with an electrochemical cell when the pressure distributor is indirectly in contact with at least one component of the electrochemical cell. Generally, a first article and a second article are in indirect contact when a path can be found between the first article and the second article that intersects only solid and / or liquid components. Such a path can be substantially linear in some embodiments. In some embodiments, a pressure distributor can be indirectly in contact with an electrochemical cell if one or more solid and / or liquid materials are placed between them, but forces can still be transmitted to the electrochemical cell via the pressure distributor.

[0079] In some embodiments, the pressure distributor is associated with the electrochemical cell when it is located within the boundary of a container that at least partially (e.g., completely) encloses the components of the electrochemical cell. For example, in some embodiments, the pressure distributor 334 may be positioned between the electrodes and a container that at least partially encloses the electrochemical cell. In some embodiments, the pressure distributor 334 may be positioned between the current collector and a container that at least partially encloses the electrochemical cell. In some embodiments, the pressure distributor 334 may be positioned next to the electrodes of the electrochemical cell and used as a current collector within a container that at least partially contains the electrodes and electrolyte of the electrochemical cell. This can be achieved, for example, by fabricating the pressure distributor 334 from a material that has sufficient conductivity to transport electrons to and / or from the electrodes of the electrochemical cell (e.g., a metal such as metal foil, a conductive polymer, etc.).

[0080] In some embodiments, the pressure distributor is associated with the electrochemical cell if it is located outside the boundary of a container that at least partially (e.g., completely) encloses the components of the electrochemical cell. For example, in some embodiments, the pressure distributor 334 may be positioned to be in direct or indirect contact with the outer surface of a container that at least partially encloses the electrodes and electrolytes of the electrochemical cell.

[0081] In some embodiments, the pressure distributor may be located at a relatively short distance from at least one electrode of the electrochemical cell. For example, in some embodiments, the shortest distance between the pressure distributor and the electrode of the electrochemical cell is less than about 10 times, less than about 5 times, less than about 2 times, less than about 1 time, less than about 0.5 times, or less than about 0.25 times the maximum cross-sectional dimension of that electrode.

[0082] In some embodiments, the pressure distributor can be associated with a specific electrode (e.g., an anode) of an electrochemical cell. For example, the pressure distributor can be in direct or indirect contact with an electrode of an electrochemical cell (e.g., an anode such as one containing lithium). In some embodiments, the pressure distributor can be located outside a container that at least partially contains the electrode but is still associated with it, for example, if only liquid and / or solid components separate the electrode from the pressure distributor. For example, in some embodiments, the pressure distributor is associated with the electrode if it is located in direct or indirect contact with a container that at least partially encloses the electrode and liquid electrolyte.

[0083] In some embodiments, a force can be applied to the electrochemical cell 321A or its components (e.g., electrodes of the electrochemical cell) via a pressure distributor 334. As used herein, a force is applied to the first component (e.g., the electrochemical cell) via the second component (e.g., the pressure distributor) when the second component transmits a force at least partially from a force source to the first component.

[0084] Forces can be applied to an electrochemical cell or its components in various ways via a pressure distributor. In some embodiments, applying a force to a pressure distributor involves applying a force to the outer surface of the pressure distributor. This can be achieved, for example, via a pressure transmitter 336. For example, in Figure 3C, the pressure transmitter 336 can be positioned to apply an anisotropic force to the electrochemical cell 321A via the pressure distributor 334 by applying a force to the surface 340 of the pressure distributor 334. As used herein, a first component is positioned to apply an anisotropic force to a second component when the first and second components are positioned such that at least a portion of the force applied to and / or via the first component can be transmitted to the second component. In some embodiments, the pressure transmitter and the pressure distributor are in direct contact. In some embodiments, one or more materials (e.g., one or more solid materials and / or liquid materials) are placed between the pressure transmitter and the pressure distributor, but the force can still be applied to the pressure distributor by the pressure transmitter. In some embodiments, the pressure transmitter and pressure distributor can be indirectly in contact so that a continuous path can be followed through solid and / or liquid materials from the pressure distributor to the electrochemical cell. In some embodiments, such a path can be substantially (e.g., perfectly) linear.

[0085] In the series of embodiments illustrated in Figure 3C, the pressure transmitter 336 and the electrochemical cell 321A are located on the opposite side of the pressure distributor 334. Thus, when an anisotropic force (e.g., an anisotropic force in the direction of arrow 150) is applied to and / or to the surface 340 by the pressure transmitter 336, the force can be transmitted through the pressure distributor 334 to the surface 342 of the electrochemical cell 321A and to the components of the electrochemical cell 321A.

[0086] In some embodiments, applying force to a pressure distributor involves applying force to the internal surface of the pressure distributor. For example, in some embodiments, force can be applied to an electrochemical cell through a pressure distributor by maintaining and / or increasing the pressure of the fluid within the pressure distributor. In a series of embodiments illustrated in Figure 3C, force can be applied to the electrochemical cell 321A through the pressure distributor 334 by transporting additional fluid through the inlet (not shown) of the pressure distributor 334 (for example, by inflating the pressure distributor 334). In some such embodiments, the movement of a pressure transmitter can be restricted so that when the pressure within the pressure distributor is maintained and / or increased, force is generated on the external surface of the electrochemical cell and / or on components of the electrochemical cell (for example, the active surface of the electrodes within the electrochemical cell). For example, in Figure 3C, when additional fluid is added to the pressure distributor 334, the pressure transmitter 336 can be configured to restrict the movement of the boundary of the pressure distributor 334 so that force is applied to the surface 342 of the electrochemical cell 321A.

[0087] In some embodiments, a fluid can be added to the pressure distributor 334 before it is positioned between the electrochemical cell 321A and the pressure transmitter 336. After the fluid is added, the pressure distributor 334 can be compressed and positioned between the electrochemical cell 321A and the pressure transmitter 336, and the compression of the fluid within the pressure distributor 334 can then generate a force that is applied to the surface 342 of the electrochemical cell 321A (and accordingly to the surface of one or more components of the electrochemical cell, such as the active surface of an electrode). Those skilled in the art who have considered this disclosure will be able to design further systems and methods for applying force to an electrochemical cell through a pressure distributor.

[0088] The fluid in the pressure distributor 334 allows the pressure transmitted through the pressure distributor 334 to be applied relatively evenly across the surface 342 of the electrochemical cell 321A (and accordingly across the surface of one or more components of the electrochemical cell, such as the active surface of the electrodes). While we do not wish to be bound by any particular theory, the presence of the fluid in the pressure distributor 334 is thought to reduce and / or eliminate points of relatively high pressure on the surface 342, as the fluid in the relatively high-pressure region is transported to the relatively low-pressure region.

[0089] In some embodiments, the degree to which a pressure distributor evenly distributes the force applied to the electrochemical cell can be enhanced if the outer surface of the pressure transmitter is properly aligned with the outer surface of the electrochemical cell or its container. For example, in a series of embodiments illustrated in Figure 3C, the outer surface 340 of the pressure transmitter 336 faces the outer surface 342 of the electrochemical cell 321A. In some embodiments, the outer surface of the pressure transmitter is substantially parallel to the outer surface of the electrochemical cell to which the force is applied. For example, in a series of embodiments shown in Figure 3C, the outer surface 340 of the pressure transmitter 336 is substantially parallel to the outer surface 342 of the electrochemical cell 321A. Two surfaces are substantially parallel to each other when they form an angle of about 10 degrees or less, as used herein. In some embodiments, two substantially parallel surfaces form an angle of about 5 degrees or less, about 3 degrees or less, about 1 degree or less, or about 0.1 degrees or less.

[0090] Pressure distributors can have a variety of preferred configurations. In some embodiments, the pressure distributor may comprise a bag or other preferred container in which a fluid is contained. In some embodiments, the pressure distributor may comprise bellows configured to deform in the direction in which a force is applied to the pressure distributor.

[0091] Pressure distributor containers can be made from a variety of materials. In some embodiments, the pressure distributor container may include flexible materials. For example, in some embodiments, the pressure distributor container may include polymers such as polyethylene (e.g., linear low-density and / or ultra-low-density polyethylene), polypropylene, polyvinyl chloride, polyvinyl dichloride, ethylene vinyl acetate, polycarbonate, polymethacrylate, polyvinyl alcohol, nylon, silicone rubber (e.g., polydimethylsiloxane), and / or other natural or synthetic rubber or plastics. In some embodiments (e.g., embodiments in which gas is used as the fluid in the pressure distributor), the pressure distributor container may include a metal layer (e.g., an aluminum metal layer), which can improve the degree to which the fluid (e.g., gas) is retained in the pressure distributor. The use of flexible materials is advantageous in some embodiments because it allows for relatively easy redistribution of the contents of the pressure distributor and can increase the degree to which forces are applied uniformly.

[0092] In some embodiments, the pressure distributor may include an elastic material. In some embodiments, the elasticity of the material from which the pressure distributor is manufactured may be selected so that the pressure distributor transmits a desired amount of force applied to the pressure distributor to adjacent components. For example, in some cases, if the pressure distributor is formed from a very flexible material, a relatively high proportion of the force applied to the pressure distributor may be used to elastically deform the pressure distributor material rather than to transmit it to adjacent electrochemical cells. In some embodiments, the pressure distributor may be formed from a material having a Young's modulus of less than about 1 GPa. Those skilled in the art can determine the Young's modulus of a given material, for example, by performing a tensile test (sometimes called a tension test). Exemplary elastic polymers (i.e., elastomers) that may be used include a general class of silicone polymers, epoxy polymers, and acrylate polymers.

[0093] In some embodiments, the pressure distributor comprises a sealed container containing a fluid. In some embodiments, the pressure distributor may comprise an open container containing a fluid. For example, in one embodiment, the pressure distributor comprises a container configured to transport a fluid through the pressure distributor and fluidically connected to a device, as will be described in more detail below.

[0094] A variety of fluids can be used in a pressure distributor. As used herein, “fluid” generally refers to a substance that is fluid and tends to conform to the shape of its container. Examples of fluids include liquids, gases, gels, viscoelastic fluids, solutions, suspensions, and fluidized particles. Generally, a fluid is a material that cannot withstand static shear stress; when shear stress is applied, the fluid experiences continuous and permanent strain. The fluid may have any suitable viscosity that allows for the flow and redistribution of the applied force.

[0095] In some embodiments, the fluid in the pressure distributor includes gases (e.g., air, nitrogen, noble gases (e.g., helium, neon, argon, krypton, xenon), gaseous refrigerants, or mixtures thereof). In some embodiments, the gas in the pressure distributor may have a relatively high molecular weight (e.g., at least about 100 g / mol), which can limit the extent to which the gas permeates through the walls of the pressure distributor. In some embodiments, the fluid in the pressure distributor may include, but is not limited to, liquids such as water, electrolytes (e.g., liquid electrolytes similar to or identical to those used in electrochemical cells), greases (e.g., petroleum jelly, Teflon grease, silicone grease), and oils (e.g., mineral oil). In some embodiments, the fluid in the pressure distributor includes gels. Suitable gels for use in pressure distributors include, but are not limited to, hydrogels (e.g., silicone gels), organogels, or xerogels. In some embodiments, the fluid includes a fluidized bed of solid particles (e.g., sand, powder, etc.). Fluidization can be achieved, for example, by passing a gas and / or liquid through the particles, and / or by vibrating a substrate on which the particles are arranged so that the particles move relative to each other.

[0096] The fluid used in conjunction with the pressure distributor can have any suitable viscosity. In some embodiments, a Newtonian fluid can be used in the pressure distributor, but some embodiments are not limited in this way and non-Newtonian fluids (e.g., shear-reducing fluids, shear-increasing fluids, etc.) can also be used. In some embodiments, the pressure distributor is approximately 1 × 10⁻⁶ at room temperature. 7 Less than centipoise (cP), approximately 1 × 10⁻⁶ 6 Less than cP, approximately 1 × 10⁻¹⁶ 5 The Newtonian fluid may also include a steady-state shear viscosity of less than cP, less than about 1000 cP, less than about 100 cP, less than about 10 cP, or less than about 1 cP (and, in some embodiments, greater than about 0.001 cP, greater than about 0.01 cP, or greater than about 0.1 cP).

[0097] In some embodiments, the fluid in the pressure distributor may be selected to be suitable for transport in and / or out of the pressure distributor. For example, in some embodiments, the fluid may be transported into the pressure distributor to apply an anisotropic force to an electrochemical cell (for example, by compressing the fluid in the pressure distributor when placed between the electrochemical cell and a pressure transmitter). As another example, the fluid may be transported in and / or out of the pressure distributor to transfer heat to and / or remove heat from components of the system.

[0098] Furthermore, the pressure transmitter 336 can employ a variety of configurations. In some embodiments, the pressure transmitter 336 is movable relative to the electrochemical cell 321A. In some such embodiments, a force can be applied to the electrochemical cell 321A via the pressure distributor 334 by bringing the pressure transmitter 336 closer to the electrochemical cell 321A and / or by maintaining separation between the electrochemical cell 321A and the pressure transmitter 336. As one particular example, in some embodiments, the pressure transmitter 336 includes a compression spring, a first applicator structure, and a second applicator structure. The first applicator structure may correspond to, for example, a plate of a rigid material, or any other suitable structure. The second applicator structure may correspond to, for example, a second plate of a rigid material, a part of the wall of a container housing the electrochemical cell, or any other suitable structure. In some embodiments, when the compression spring is compressed between the applicator structures, a force can be applied to the surface 342 of the electrochemical cell 321A. In some embodiments, Belleville washers, mechanical screws, pneumatic devices, weights, air cylinders, and / or hydraulic cylinders may be used instead of or in addition to compression springs. In some embodiments, force can be applied to an electrochemical cell using compression elements (or constricting elements) (e.g., elastic bands, turnbuckle bands, etc.) positioned around one or more outer surfaces of the electrochemical cell. Various preferred methods for applying force to an electrochemical cell are described, for example, in the U.S. Patent Application Publication No. 2010 / 0035128 of 4 August 2009, titled "Application of Force in Electrochemical Cells," which is incorporated herein by reference in its entirety for all purposes.

[0099] In some embodiments, the pressure transmitter 336 is substantially immovable relative to the electrochemical cell 321A, and a force can be applied to the electrochemical cell, for example, by pressurizing the pressure distributor 334. In some such embodiments, the substantially immovable pressure transmitter 336 restricts the movement of one or more boundaries of the pressure distributor 334, thereby applying an anisotropic force to the electrochemical cell 321A, so that a force can be applied to the electrochemical cell by pressurizing the pressure distributor.

[0100] In some embodiments, the pressure transmitter constitutes all or part of a substantially rigid structure (e.g., a package enclosing an electrochemical cell), and the movement of the pressure transmitter may be limited to the extent that the substantially rigid structure is not flexible. In some embodiments, the pressure transmitter may constitute a structure integrated with at least some of the other components of the system, thereby limiting its movement. For example, in some embodiments, the pressure transmitter may constitute at least part of one or more walls of the package in which the electrochemical cell 321A and the pressure distributor 334 are located. In one particular example, the pressure transmitter 336 may form a first wall of the package containing the electrochemical cell 321A, while the substrate 332 may form a second wall of the package (e.g., opposite the first wall). In some embodiments, the movement of the pressure transmitter 336 may be limited by applying forces to and / or on the pressure transmitter such that its movement is restricted. In any of these cases, in some embodiments, a force can be applied to the electrochemical cell by adding fluid to the pressure distributor 334 and / or maintaining the amount of fluid in the pressure distributor 334.

[0101] Figure 3C shows a set of embodiments in which a single pressure transmitter and a single pressure distributor are used to apply force to an electrochemical cell. However, in some embodiments, more than one pressure distributor and / or more than one pressure transmitter may be employed. For example, in some embodiments, the system includes a second pressure distributor located below the electrochemical cell 321A and a second pressure transmitter located below the second pressure distributor. In some embodiments, for example, a force can be applied to the surface of the second pressure distributor by applying force to and / or through the second pressure transmitter, thereby applying a force substantially evenly distributed to the outer surface of the electrochemical cell 321A through the second pressure distributor.

[0102] In some embodiments, it is possible to transport a fluid to and / or from a pressure distributor in order to transfer heat to and / or remove heat from the electrochemical cell 321A. For example, the pressure distributor 334 may include an inlet and an outlet configured to transport a fluid through the pressure distributor 334. As the fluid is transported through the pressure distributor 334, it can absorb heat from the electrochemical cell 321A and be transported away from the system through the outlet. To transport the fluid through the pressure distributor, for example, a pump, a vacuum, or any other suitable device can be used.

[0103] In some embodiments, the fluid used in conjunction with the pressure distributor can be selected to cool or heat the system to a desired degree. For example, in some embodiments, the fluid in the pressure distributor may include water, ethylene glycol, diethylene glycol, propylene glycol, polyalkylene glycol (PAG), oil (e.g., mineral oil, castor oil, silicone oil, fluorocarbon oil, etc.), and / or coolants (e.g., Freon, chlorofluorocarbon, perfluorocarbon, etc.).

[0104] The embodiments described herein can be used with a variety of electrochemical cells. Primary (disposable) electrochemical cells and secondary (rechargeable) electrochemical cells can be used in conjunction with the embodiments described herein, but some embodiments favorably use secondary electrochemical cells, for example, due to the advantages brought about by the application of uniform force during the (re)charging process. In some embodiments, the electrochemical cell includes lithium-based electrochemical cells such as lithium-sulfur electrochemical cells (and assemblies of multiple cells such as batteries).

[0105] While several embodiments can be found for use in a wide variety of electrochemical devices, an example of such a device is provided in Figure 3D for illustrative purposes only. In Figure 3D, a typical embodiment of the electrochemical cell 321A includes a cathode 310, an anode 312, and an electrolyte 314 that is electrochemically in communication with the cathode and anode.

[0106] In some embodiments, the electrochemical cell 321A may optionally be at least partially enclosed by a containment structure 316. The containment structure 316 may have a variety of shapes, including, but not limited to, a cylinder, a prism (e.g., a triangular prism, a cuboid, etc.), a cube, or any other shape. In some embodiments, a pressure distributor may be associated with the electrochemical cell 321A by positioning the pressure distributor outside the containment structure 316, in direct or indirect contact with surfaces 318A and / or 318B. When positioned in this manner, the pressure distributor may be configured to apply force directly or indirectly to surfaces 318A and / or 318B of the containment structure 316, as described above. In some embodiments, the pressure distributor may be positioned between the cathode 310 and the containment structure 316, or between the anode 312 and the containment structure 316. In some such embodiments, the storage structure can function as a pressure transmitter, and / or a separate pressure transmitter can be configured to apply force to a pressure distributor via the storage structure.

[0107] A typical electrochemical cell system also naturally includes current collectors, external circuits, and so on. Those skilled in the art will be familiar with the many configurations that can be utilized, such as the general schematic configurations shown in the drawings and described herein.

[0108] The components of the electrochemical cell 321A may, in some cases, be assembled such that the electrolyte is positioned between the cathode and anode in a planar configuration. For example, in the embodiment shown in Figure 3D, the cathode 310 of the electrochemical cell 321A is substantially planar. A substantially planar cathode can be formed, for example, by coating a cathode slurry onto a planar substrate such as a metal foil or other suitable substrate, which may be included in the assembly of the electrochemical cell 321A (not shown in Figure 3D) or removed from the cathode 310 before assembly of the electrochemical cell. Furthermore, in Figure 3D, the anode 312 is shown as substantially planar. A substantially planar anode can be formed, for example, by forming a sheet of metallic lithium, by forming an anode slurry on a planar substrate, or by any other suitable method. The electrolyte 314 is also shown as substantially planar in Figure 3D.

[0109] In some embodiments, the electrochemical cell 321A may include electrodes containing metals such as elemental metals and / or metal alloys. As one particular example, in some embodiments, the electrochemical cell 321A may have an anode containing elemental lithium (e.g., elemental lithium metal and / or lithium alloy). In some embodiments, the anisotropic force applied to the electrochemical cell is sufficiently large to affect the surface morphology of the metals within the electrodes of the electrochemical cell, as will be described in more detail below.

[0110] Figure 3D shows an electrochemical cell arranged in a planar configuration, but it should be understood that any electrochemical cell arrangement can be constructed in any configuration by employing the principles of several embodiments. In addition to the shapes exemplified in Figure 3D, the electrochemical cells described herein may be any other shapes, including but not limited to cylinders, folded multilayer structures, prisms (e.g., triangular prisms, rectangular prisms, etc.), "Swiss-rolls," and non-planar multilayer structures. Further configurations are described in U.S. Patent Application No. 11 / 400,025, filed April 6, 2006, by Affinito et al., entitled "Electrode Protection in both Aqueous and Non-Aqueous Electrochemical Cells, including Rechargeable Lithium Batteries," which is incorporated herein by reference in its entirety.

[0111] In some embodiments, the cathode and / or anode include at least one active surface. As used herein, the term “active surface” is used to describe the surface of an electrode that is in physical contact with the electrolyte and on which electrochemical reactions may occur. For example, in a series of embodiments illustrated in Figure 3D, the cathode 310 includes a cathode active surface 320, and the anode 312 includes an anode active surface 322.

[0112] In some embodiments, the anisotropic force applied to the pressure transmitter 336 and / or via the pressure distributor 334 (and ultimately to the surface 342 of the electrochemical cell 321A in some cases) includes a component perpendicular to the active surface of the electrode in the electrochemical cell (e.g., an anode containing lithium metal). Thus, applying an anisotropic force to the electrochemical cell via the pressure distributor 334 can result in an anisotropic force being applied to the active surface of the electrode in the electrochemical cell (e.g., an anode). In the case of a planar electrode surface, the applied force may include an anisotropic force having a component perpendicular to the electrode active surface at the point where the force is applied. For example, referring to a series of embodiments shown in Figures 3C and 3D, an anisotropic force in the direction of arrow 370 may be applied to the electrochemical cell 321A via the pressure distributor 334. The anisotropic force applied in the direction of arrow 370 includes a component 372 that is perpendicular to the anode active surface 322 and perpendicular to the cathode active surface 320. Furthermore, the anisotropic force applied in the direction of arrow 370 will include a component 374 that is not perpendicular (but actually parallel) to the anode active surface 322 and cathode active surface 320.

[0113] In the case of a curved surface (e.g., concave or convex), the force applied to the electrochemical cell may include an anisotropic force having a component perpendicular to the plane tangent to the curved surface at the point where the force is applied.

[0114] In one embodiment, the system and method are configured to apply an anisotropic force having a component perpendicular to the active surface of the electrode (e.g., anode) to the electrochemical cell during at least one period of charging and / or discharging the cell. In some embodiments, the force may be applied continuously, over a single period, or over multiple periods in which the duration and / or frequency may vary.

[0115] The magnitude of the applied force is, in some embodiments, large enough to improve the performance of the electrochemical cell. In some embodiments, the electrode active surface (e.g., the anode active surface) and the anisotropic force may be selected together such that the anisotropic force affects the surface morphology of the electrode active surface, thereby suppressing the increase in the electrode active surface area due to charging and discharging, and that under otherwise essentially identical conditions, the electrode active surface area increases more significantly over the charge-discharge cycle, even when no anisotropic force is present. "Essentially identical conditions" means, as used herein, conditions that are similar or identical except for the application of force and / or the magnitude of the force. For example, otherwise identical conditions may mean a cell that is identical but not configured to apply an anisotropic force to the electrochemical cell in question (e.g., by brackets or other connections).

[0116] The electrode active surface and anisotropic force can be readily selected together by those skilled in the art to obtain the results described herein. For example, if the electrode active surface is relatively soft, the force component perpendicular to the electrode active surface may be selected to be lower. If the electrode active surface is harder, the force component perpendicular to the electrode active surface may be higher. Those skilled in the art, considering this disclosure, can readily select anode materials, alloys, mixtures, etc., having known or predictable properties, or can readily test the hardness or softness of such surfaces, and can readily select cell construction techniques and arrangements to provide appropriate forces to achieve those described herein. Simple tests can be performed, for example, by arranging a series of active materials and applying a series of forces perpendicular to each active surface (or a component perpendicular to the active surface), and determining the morphological effect of the forces on the surface, either without a cell cycle (for prediction of selected combinations during a cell cycle) or with a cell cycle involving selection and observation of associated results.

[0117] As described above, in some embodiments, during at least one period of charging and / or discharging the cell, an anisotropic force having a component perpendicular to the electrode active surface (e.g., of the anode) is applied to an extent effective in suppressing the increase in the surface area of ​​the electrode active surface compared to the increase in the surface area in the absence of anisotropic force. The component of the anisotropic force perpendicular to the electrode active surface is, for example, at least about 20, at least about 25, at least about 35, at least about 40, at least about 50, at least about 75, at least about 90, at least about 100, at least about 125, at least about 150, at least about 200, at least about 300, at least about 400, or at least about 500 Newtons / cm² (N / cm 2 The pressure can be defined as follows: In some embodiments, the component of the anisotropic force perpendicular to the anode active surface is, for example, about 500 N / cm². 2 Less than approximately 400 N / cm² 2 Less than approximately 300 N / cm² 2 Less than approximately 200 N / cm² 2 Less than approximately 190 N / cm² 2 Less than approximately 175 N / cm² 2 Less than approximately 150 N / cm² 2 Less than approximately 125 N / cm² 2 Less than approximately 115 N / cm² 2 Less than or approximately 110 N / cm² 2 A pressure less than a certain value can be defined. In this specification, force and pressure are generally expressed in Newtons and Newtons per unit area, respectively, but force and pressure can also be expressed in kgf (kilograms-force) and kgf per unit area, respectively. Those skilled in the art will be familiar with kgf-based units and will understand that 1 kgf is approximately equal to 9.8 Newtons.

[0118] In some embodiments, the component of anisotropic force perpendicular to the active surface of an electrode in an electrochemical cell defines a pressure where the component is at least about 50%, at least about 75%, at least about 100%, or at least about 120% of the yield stress of that electrode (e.g., during charging and / or discharging of the electrochemical cell). In some embodiments, the component of anisotropic force perpendicular to the active surface of an electrode in an electrochemical cell defines a pressure where the component is less than about 250% or less than about 200% of the yield stress of that electrode (e.g., during charging and / or discharging of the electrochemical cell). For example, in some embodiments, the electrochemical cell may include an anode (e.g., an anode comprising lithium metal and / or a lithium alloy), and the component of the applied anisotropic force perpendicular to the anode active surface may define a pressure where the component is at least about 50%, at least about 75%, at least about 100%, or at least about 120% (and / or less than about 250% or less than about 200% of the yield stress of the anode). In some embodiments, the electrochemical cell may include a cathode, and the component of anisotropic force perpendicular to the cathode active surface may define a pressure of at least about 50%, at least about 75%, at least about 100%, or at least about 120% (and / or less than about 250% or less than 200% of the cathode's yield stress).

[0119] In some cases, anisotropic forces can define a pressure that is relatively uniform across one or more external surfaces of an electrochemical cell and / or across one or more active surfaces of electrodes within the electrochemical cell. In some embodiments, at least about 50%, at least about 75%, at least about 85%, at least about 90%, at least about 95%, or at least about 98% of the area of ​​one or more external surfaces of an electrochemical cell and / or the area of ​​one or more active surfaces of electrodes (e.g., anodes) defines a uniform region containing a substantially uniform distribution of pressure defined by the anisotropic forces. In this specification, “surface of electrochemical cell” and “surface of electrode” refer to the geometric surfaces of the electrochemical cell and electrode, and will be understood by those skilled in the art to refer to the surfaces that define the outer boundaries of the electrochemical cell and electrode, for example, areas that can be measured by a macroscopic measuring tool (e.g., a ruler), and not to include internal surface areas (e.g., the area within the pores of a porous material such as foam, or the surface area of ​​the fibers of a mesh that are contained within the mesh and do not define the outer boundary).

[0120] In some embodiments, the pressure is substantially uniformly distributed across the surface if any continuous region covering about 10%, about 5%, about 2%, or about 1% of the uniform region (as described in the previous paragraph) contains an average pressure that varies by less than about 25%, about 10%, about 5%, about 2%, or about 1% of the average pressure over the entire uniform region.

[0121] In other words, in some embodiments, at least about 50% (or at least about 75%, at least about 85%, at least about 90%, at least about 95%, or at least about 98%) of the surface area of ​​the electrochemical cell and / or the active area of ​​the electrode defines a first continuous region of essentially uniform applied pressure, the first region having a first average applied pressure. In some cases, any continuous region covering about 10% (or about 5%, about 2%, or about 1%) of the first continuous region of the electrochemical cell surface and / or electrode includes a second average applied pressure that varies by less than about 25% (or less than about 10%, about 5%, about 2%, or about 1%) of the first average applied pressure across the first continuous region.

[0122] Those skilled in the art can determine the average applied pressure within a surface by, for example, determining the force levels applied at a representative number of points within the surface, integrating a three-dimensional plot of applied pressure as a function of the position of the surface, and dividing the integral by the surface area of ​​the surface. Those skilled in the art can also create a plot of pressure applied to the entire surface by, for example, using a "Tekscan I-Scan system" for measuring the pressure field.

[0123] The anode of the electrochemical cell described herein may contain various anode active materials. As used herein, the term “anode active material” refers to any electrochemically active species associated with the anode. For example, the anode may contain a lithium-containing material, where lithium is the anode active material. Suitable electroactive materials for use as the anode active material in the anode of the electrochemical cell described herein include, but are not limited to, lithium metals such as lithium foil or lithium deposited on a conductive substrate, and lithium alloys (e.g., lithium-aluminum alloys and lithium-tin alloys). Methods for placing the negative electrode material (e.g., an alkali metal anode such as lithium) on a substrate include thermal evaporation, sputtering, jet vapor deposition, and laser ablation. Alternatively, if the anode comprises lithium foil, or lithium foil and a substrate, these can be bonded together to form the anode by lamination as known in the art.

[0124] In one embodiment, the electroactive lithium-containing material of the anode active layer contains more than 50% by weight of lithium. In another embodiment, the electroactive lithium-containing material of the anode active layer contains more than 75% by weight of lithium. In yet another embodiment, the electroactive lithium-containing material of the anode active layer contains more than 90% by weight of lithium. Further materials and arrangements suitable for use in the anode are described, for example, in U.S. Patent Application Publication No. 2010 / 0035128 of Scordilis-Kelley et al., titled "Application of Force in Electrochemical Cells," filed on 4 August 2009, which is incorporated herein by reference in its entirety for all purposes.

[0125] The cathodes of the electrochemical cells described herein may include a variety of cathode active materials. As used herein, the term “cathode active material” refers to any electrochemically active species associated with a cathode. Suitable electroactive materials for use as cathode active materials in the cathodes of some embodiments of electrochemical cells include, but are not limited to, one or more metal oxides, one or more intercalation materials, electroactive transition metal chalcogenides, electroactive conductive polymers, sulfur, carbon, and / or combinations thereof.

[0126] In some embodiments, the cathode active material comprises one or more metal oxides. In some embodiments, an intercalation cathode (e.g., a lithium intercalation cathode) may be used. Non-limiting examples of suitable materials that can intercalate ions of electroactive material (e.g., alkali metal ions) include metal oxides, titanium sulfide, and iron sulfide. In some embodiments, the cathode is an intercalation cathode comprising a lithium transition metal oxide or lithium transition metal phosphate. Further examples include Li x COO2 (for example, Li 1.1 CoO2), Li x KiO2, Li x MnO2, Li x Mn2O4 (for example, Li 1.05 Mn2O4), Li x CoPO4, Li x MnPO4, LiCo x Ni (1-x) O2 and LiCo x Ni y Mn (1-x-y) O2 (for example, LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 O2, LiLiLi 3 / 5 Mn 1 / 5 Co1 / 5O2, LiNi 4 / 5 Mn 1 / 10 Co 1 / 10 O2, LiLiLi 1 / 2 Mn 3 / 10 Co 1 / 5Examples include (O2). x may be 0 or greater and 2 or less. When the electrochemical cell is completely discharged, x is typically 1 or greater and 2 or less, and when the electrochemical cell is completely charged, it is less than 1. In some embodiments, a completely charged electrochemical cell may have x values ​​of 1 or greater and 1.05 or less, 1 or greater and 1.1 or less, or 1 or greater and 1.2 or less. Further examples include (0 <x≦1)であるLi x NiPO4, LiMn (x+y=2) x Ni y O4 (for example, LiMn 1.5 Ni 0.5 LiNi (O4), (x+y+z=1) x Co y Al z Examples include O2, LiFePO4, and combinations thereof. In some embodiments, the electroactive material in the cathode comprises a lithium transition metal phosphate (e.g., LiFePO4), which in some embodiments can be substituted with a borate and / or silicate.

[0127] As described above, in some embodiments, the cathode active material comprises one or more chalcogenides. As used herein, the term “chalcogenide” refers to a compound comprising one or more elements: oxygen, sulfur, and selenium. Examples of suitable transition metal chalcogenides include, but are not limited to, electroactive oxides, sulfides, and selenides of transition metals selected from the group consisting of Mn, V, Cr, Ti, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Os, and Ir. In one embodiment, the transition metal chalcogenide is selected from the group consisting of electroactive oxides of nickel, manganese, cobalt, and vanadium, as well as electroactive sulfides of iron. In one embodiment, the cathode comprises one or more materials from manganese dioxide, iodine, silver chromate, silver oxide and vanadium pentoxide, copper oxide, copper oxyphosphate, lead sulfide, iron sulfide, lead bismuthate, bismuth trioxide, cobalt dioxide, copper chloride, manganese dioxide and carbon. In another embodiment, the cathode active layer comprises an electroactive conductive polymer. Examples of suitable electroactive conductive polymers include, but are not limited to, electroactive and electronically conductive polymers selected from the group consisting of polypyrroles, polyanilines, polyphenylenes, polythiophenes, and polyacetylenes. Examples of conductive polymers include polypyrroles, polyanilines, and polyacetylenes.

[0128] In some embodiments, the electroactive material for use as a cathode active material in the electrochemical cell described herein includes an electroactive sulfur-containing material. “Electroactive sulfur-containing material,” as used herein, refers to a cathode active material containing any form of the element sulfur, wherein the electrochemical activity includes the oxidation or reduction of the sulfur atom or part thereof. The properties of electroactive sulfur-containing materials useful in some embodiments can vary widely, as is known in the art. For example, in one embodiment, the electroactive sulfur-containing material contains elemental sulfur. In another embodiment, the electroactive sulfur-containing material contains a mixture of elemental sulfur and a sulfur-containing polymer. Therefore, suitable electroactive sulfur-containing materials include, but are not limited to, elemental sulfur and organic materials (which may or may not be polymers) containing sulfur atoms and carbon atoms. Suitable organic materials include those further containing heteroatoms, conductive polymer segments, composites, and conductive polymers.

[0129] In some embodiments, the electroactive sulfur-containing material of the cathode active layer contains more than 50% by weight of sulfur. In another embodiment, the electroactive sulfur-containing material contains more than 75% by weight of sulfur. In yet another embodiment, the electroactive sulfur-containing material contains more than 90% by weight of sulfur.

[0130] In some embodiments, the cathode active layer may contain about 20 to 100% by weight of electroactive cathode material (measured, for example, after a suitable amount of solvent has been removed from the cathode active layer and / or after the layer has been properly cured). In one embodiment, the amount of electroactive sulfur-containing material in the cathode active layer is in the range of 5 to 30% by weight of the cathode active layer. In another embodiment, the amount of electroactive sulfur-containing material in the cathode active layer is in the range of 20 to 90% by weight of the cathode active layer.

[0131] Further materials suitable for use in cathodes, and suitable methods for manufacturing cathodes, are described, for example, in U.S. Patent No. 5,919,587, filed on 21 May 1997, entitled "Novel Composite Cathodes, Electrochemical Cells Comprising Novel Composite Cathodes, and Processes for Fabricating Same," and in U.S. Patent Application Publication No. 2010 / 0035128, filed on 4 August 2009, entitled "Application of Force in Electrochemical Cells," each of which is incorporated herein by reference in whole for all purposes.

[0132] Various electrolytes can be used in conjunction with the electrochemical cells described herein. In some embodiments, the electrolyte may include a non-solid electrolyte, which may or may not be incorporated into a porous separator. As used herein, the term “non-solid” is used to refer to a material that cannot withstand static shear stress and, when shear stress is applied, experiences continuous and permanent strain. Examples of non-solids include, for example, liquids and deformable gels.

[0133] The electrolytes used in the electrochemical cells described herein function as a medium for the storage and transport of ions, and in the special cases of solid and gel electrolytes, these materials may further function as a separator between the anode and the cathode. Any liquid, solid, or gel material capable of storing and transporting ions, or any material that facilitates the transport of ions (e.g., lithium ions) between the anode and the cathode, can be used. Examples of materials suitable for use as electrolytes are described, for example, in U.S. Patent Application Publication No. 2010 / 0035128, titled "Application of Force in Electrochemical Cells," filed on 4 August 2009, and which is incorporated herein by reference in its entirety for all purposes.

[0134] U.S. Patent Application No. 16 / 527,903, filed on 31 July 2019, entitled "Multiplexed Charge Discharge Battery Management System," is incorporated herein by reference in its entirety for all purposes.

[0135] The following references are incorporated herein by reference in their entirety for the purposes of this document. U.S. Patent No. 7,247,408, filed on May 23, 2001, for the invention titled "Lithium Anodes for Electrochemical Cells"; U.S. Patent No. 5,648,187, filed on March 19, 1996, for the invention titled "Stabilized Anode for Lithium-Polymer Batteries"; U.S. Patent No. 5,961,672, filed on July 7, 1997, for the invention titled "Stabilized Anode for lithium-Polymer Batteries"; U.S. Patent No. 5,919,587, filed on May 21, 1997, for the invention titled "Novel Composite Cathodes, Electrochemical Cells Comprising Novel Composite Cathodes, and Processes for Fabricating Same"; The invention, titled "Rechargeable Lithium / Water, Lithium / Air Batteries," was published in U.S. Patent Application Publication No. 2007 / 0221265 and filed on April 6, 2006, as U.S. Patent Application No. 11 / 400,781; The invention, titled "Swelling Inhibition in Lithium Batteries," was published as International Publication No. 2009 / 017726, with International Application Number PCT / US2008 / 009158, filed on July 29, 2008; U.S. Patent Application No. 12 / 312,764, filed on May 26, 2009, published as U.S. Patent Application Publication No. 2010 / 0129699, with the title of the invention "Separation of Electrolytes"; The invention, titled "Primer for Battery Electrode," was published as International Publication No. 2009 / 054987, with International Application Number PCT / US2008 / 012042, filed on October 23, 2008; The invention is titled "Protective Circuit for Energy-Storage Device," and was published as U.S. Patent Application Publication No. 2009 / 0200986, U.S. Patent Application No. 12 / 069,335, filed on February 8, 2008. The invention is titled "Electrode Protection in both Aqueous and Non-Aqueous Electrochemical Cells, including Rechargeable Lithium Batteries," and was published as U.S. Patent Application Publication No. 2007 / 0224502, U.S. Patent Application No. 11 / 400,025, filed on April 6, 2006; The invention is titled "Lithium Alloy / Sulfur Batteries," and was published in U.S. Patent Application Publication No. 2008 / 0318128, U.S. Patent Application No. 11 / 821,576, filed on June 22, 2007. The invention is titled "Lithium Sulfur Rechargeable Battery Fuel Gauge Systems and Methods," and was published in U.S. Patent Application Publication No. 2006 / 0238203, U.S. Patent Application No. 11 / 111,262, filed on April 20, 2005. The invention is titled "Co-Flash Evaporation of Polymerizable Monomers and Non-Polymerizable Carrier Solvent / Salt Mixtures / Solutions," and was published in U.S. Patent Application Publication No. 2008 / 0187663, U.S. Patent Application No. 11 / 728,197, filed on March 23, 2007. The invention, titled "Electrolyte Additives for Lithium Batteries and Related Methods," was published as International Publication No. 2009 / 042071, with International Application Number PCT / US2008 / 010894, filed on September 19, 2008; The invention, titled "Porous Electrodes and Associated Methods," was published as International Publication No. 2009 / 089018, with International Application Number PCT / US2009 / 000090, filed on January 8, 2009; The invention is titled "Application of Force In Electrochemical Cells" and was published as U.S. Patent Application Publication No. 2010 / 0035128, U.S. Patent Application No. 12 / 535,328, filed on August 4, 2009; U.S. Patent Application No. 12 / 727,862, filed March 19, 2010, for the invention titled "Cathode for Lithium Battery"; U.S. Patent Application No. 12 / 471,095, filed May 22, 2009, for the invention titled "Hermetic Sample Holder and Method for Performing Microanalysis Under Controlled Atmosphere Environment"; (Claiming priority from Provisional Patent Application No. 61 / 236,322, filed August 24, 2009, for the invention titled "Release System for Electrochemical Cells") U.S. Patent Application No. 12 / 862,513, filed August 24, 2010, for the invention titled "Release System for Electrochemical Cells"; U.S. Provisional Patent Application No. 61 / 376,554, filed August 24, 2010, for the invention titled "Electrically Non-Conductive Materials for Electrochemical Cells"; The invention is titled "Electrochemical Cell," and was published in U.S. Patent Application Publication No. 2011 / 0177398, U.S. Patent Application No. 12 / 862,528, filed on August 24, 2010; The invention, titled "Electrochemical Cells Comprising Porous Structures Comprising Sulfur," was published in U.S. Patent Application Publication No. 2011 / 0070494, U.S. Patent Application No. 12 / 862,563, filed on August 24, 2010 [Agent Reference Number: S1583.70029US00]; The invention, titled "Electrochemical Cells Comprising Porous Structures Comprising Sulfur," was published in U.S. Patent Application Publication No. 2011 / 0070491, U.S. Patent Application No. 12 / 862,551, filed on August 24, 2010 [Agent Reference Number: S1583.70030US00]; The invention, titled "Electrochemical Cells Comprising Porous Structures Comprising Sulfur," was published in U.S. Patent Application Publication No. 2011 / 0059361, U.S. Patent Application No. 12 / 862,576, filed on August 24, 2010 [Agent Reference Number: S1583.70031US00]; The invention, titled "Electrochemical Cells Comprising Porous Structures Comprising Sulfur," was published in U.S. Patent Application Publication No. 2011 / 0076560, U.S. Patent Application No. 12 / 862,581, filed on August 24, 2010 [Agent Reference Number: S1583.70024US01]; U.S. Patent Application No. 61 / 385,343, filed September 22, 2010 [Agent Reference Number: S1583.70033US00] for the invention titled "Low Electrolyte Electrochemical Cells"; and U.S. Patent Application No. 13 / 033,419 [S1583.70034US00], filed February 23, 2011, for the invention titled "Porous Structures for Energy Storage Devices". All other patents and patent applications disclosed herein are also incorporated herein by reference in whole for all purposes.

[0136] Figure 4A shows a typical high-level process 400A for controlling the charging speed or charging current of the above cell. Improvements to the typical process 400A are described in detail in the following paragraphs.

[0137] In some embodiments, a typical process 400A may include an improvement (act) 430A, in which an electrochemical cell (such as the electrochemical cell 121A described above) may be controlled to charge for at least a portion of the charge cycle at a charge rate or charge current lower than the discharge rate or discharge current of at least a portion of the previous discharge cycle, as described herein.

[0138] In some embodiments, process 400A may then be terminated or repeated as needed, such as for more charge / discharge cycles.

[0139] Figure 4B shows a typical process 400B for controlling the charging rate or charging current of a cell (such as the electrochemical cell 121A mentioned above). Improvements to the typical process 400B are described in detail in the following paragraphs.

[0140] In some embodiments, a typical process 400B may include an improvement 410 in which the characteristics of the cell can be monitored (for example, by a controller such as 114 and a sensor 116 as described herein).

[0141] In some embodiments, a typical process 400B may then optionally proceed to improvement 420, which may be considered to determine whether at least one threshold is met, as described herein. For example, the threshold may be a threshold amount (or rate or current) of discharge in the discharge history, a threshold measurement of a monitored characteristic, such as a pressure measurement on the cell.

[0142] In some embodiments, if the threshold is met, representative process 400B then proceeds to improvement 430A, where the cell may be controlled (e.g., by controller 114) to charge at a charge rate or charge current lower than the discharge rate or discharge current for a portion of the cell's discharge cycle. For example, if the cell has had a discharge cycle or history of discharging at 300 mA, the cell may be controlled to charge at 150 mA or less, as described herein. Alternatively, if the threshold is not met, monitoring of the characteristics may continue.

[0143] In some embodiments, the typical process 400B may then optionally proceed to improvement 431B, in which the induced discharge of the cell may be triggered by the controller. The induced discharge may be triggered at various timings and for various reasons, as described herein.

[0144] In some embodiments, a typical process 400B may then optionally proceed to either improvement 432 or 434. For example, if process 400B proceeds from improvement 431B to improvement 432, the cell may be controlled to charge at a charge rate at least twice as low as its discharge rate, as described herein.

[0145] Alternatively or additionally, process 400B may proceed from improvement 431B to improvement 434, in which case the cell may be controlled to charge at a charge rate four times lower than its discharge rate, as described herein.

[0146] In some embodiments, process 400B may then be terminated or repeated as needed, such as for more charge / discharge cycles.

[0147] Please note that although either improvement 432 and / or 434 are shown as separate improvements in Figure 4B, they may actually be integrated with improvement 430A.

[0148] Figure 4C shows a typical high-level process 400C for inducing the discharge of the above cell. Improvements to the typical process 400C are described in detail in the following paragraphs.

[0149] In some embodiments, a typical process 400C may include an improvement 430C in which an induced discharge of an electrochemical cell (such as the electrochemical cell 121A described above) may be induced before and / or after the charging process, as described herein.

[0150] In some embodiments, process 400C may then be terminated or repeated as needed, such as for more charge / discharge cycles.

[0151] Figure 4D shows a typical process 400D for inducing cell discharge. Improvements to the typical process 400D are described in detail in the following paragraphs.

[0152] In some embodiments, a typical process 400D may optionally include an improvement 410 in which the characteristics of the cell can be monitored as described herein.

[0153] In some embodiments, a typical process 400D may then optionally proceed to improvement 420, which may be considered to determine whether at least one threshold has been met. For example, the threshold may be a threshold value of a monitored characteristic, such as a threshold amount (or speed or current) of discharge in the discharge history, a pressure measurement on the cell, or the thickness or size of the cell.

[0154] In some embodiments, if the threshold is met, the typical process 400D may then proceed to improvement 430C, and the induced discharge of the cell may be induced by a controller (e.g., controller 114) as described herein. For example, the threshold may be met if the charge / discharge history of the cell indicates, as described herein, that a discharge cycle has ended, a discharge cycle and / or discharge process is still in progress, a charge cycle has ended, or a charge cycle and / or charge process is about to begin. Alternatively, if the threshold is not met, the characteristics may continue to be monitored.

[0155] In some embodiments, a typical process 400D may then optionally proceed to an improvement 431D, in which the cell may be controlled to charge at a lower charge rate or charge current for at least a portion of the charge cycle than for at least a portion of the previous discharge cycle, as described herein.

[0156] In some embodiments, a typical process 400D may then optionally proceed to either improvement 432 or 434. For example, if process 400D proceeds from improvement 431D to improvement 432, the cell may be controlled to charge at a charge rate at least twice as low as its discharge rate.

[0157] Alternatively or additionally, process 400D may progress from improvement 431D to improvement 434, in which the cell may be controlled to charge at a charge rate four times lower than its discharge rate.

[0158] In some embodiments, process 400D may then be terminated or repeated as needed, such as for more charge / discharge cycles.

[0159] Although either improvement 432 and / or 434 are shown as separate improvements in Figure 4D, it should be understood that they may actually be considered as part of improvement 430C.

[0160] Figure 5A shows a typical process 500A for monitoring cell characteristics, inducing discharge, or controlling the charging speed or charging current of the cell. Improvements to the typical process 500A are described in detail in the following paragraphs.

[0161] In some embodiments, a typical process 500A may include an improvement 510 in which the characteristics of the cell can be monitored (for example, by a controller such as 114 and a sensor 116 as described herein).

[0162] In some embodiments, process 500A then proceeds from improvement 510 to improvement 530, and based on monitoring in improvement 510, induced discharge and / or controlled charging of the cell may be triggered by the controller as described herein.

[0163] In some embodiments, process 500A may then be terminated or repeated as necessary.

[0164] Figure 5B shows a typical process 500B for monitoring cell characteristics and inducing discharge or controlling the charging rate or charging current of the cell. Improvements to the typical process 500B are described in detail in the following paragraphs.

[0165] In some embodiments, a typical process 500B may include an improvement 510 in which the characteristics of the cell can be monitored (for example, by a controller such as 114 and a sensor 116 as described above).

[0166] In some embodiments, a typical process 500B may then optionally proceed to improvement 520, which may be considered to determine whether at least one threshold has been met, as described herein. For example, the threshold may be a threshold value of a monitored characteristic, such as a threshold amount (or rate or current) of discharge in the discharge history, a pressure measurement on the cell, or the thickness or size of the cell.

[0167] In some embodiments, if the threshold is met, the typical process 500B then proceeds to improvement 530, where the induced discharge of the cell may be triggered by a controller (e.g., controller 114) as described herein. For example, the threshold may be met if the charge / discharge history of the cell indicates, as described herein, that a discharge cycle has ended, a discharge cycle and / or discharge process is still in progress, a charge cycle has ended, or a charge cycle and / or charge process is about to begin. Alternatively, if the threshold is not met, monitoring of the characteristics may continue.

[0168] In some embodiments, a typical process 500B can then optionally proceed to either improvement 532 or 534. For example, if process 500B proceeds from improvement 530 to improvement 532, the battery may be controlled to charge at a charge rate at least twice as low as its discharge rate.

[0169] Alternatively or additionally, if process 500B proceeds from improvement 530 to improvement 534, the cell may be controlled to charge at a charge rate four times lower than its discharge rate.

[0170] In some embodiments, process 500B may then be terminated or repeated as necessary.

[0171] Although either improvement 532 and / or 534 are shown as separate improvements in Figure 5B, it should be understood that they may actually be considered as an integral part of improvement 530.

[0172] The inventors recognize and understand that some of the embodiments described above may, when implemented, result in various improvements over the prior art. [Examples]

[0173] In Examples 1-5 and Tables 1-4 below, the cell density is 10-12 kg / cm³. 2 It is cycle-tested under pressure.

[0174] (Example 1): Example 1 demonstrates that when a cell is cycle-tested at the same charge and discharge rates (current or time) over a wide range of speeds, the cycle life is short. A cell having an NCM111 cathode, a 15 μm vapor-deposited lithium anode, and an electrolyte was tested at 10 kg / cm². 2 The test was performed under the specified pressure. The electrolyte was a 1 mole solution of lithium hexafluoride phosphate in a weight ratio of ethylene carbonate to dimethyl carbonate of 2:1. The total surface area of ​​the above cell active electrode was 99.4 cm². 2 The cell capacity was 200mAh. The cells were charged to 4.35V and discharged to 3.2V with the currents shown in Table 1 below. The charging and discharging currents were the same. In the charge / discharge current range of 40-200mA (a 5-fold difference in current), all cells showed a short cycle life of 38-56 cycles. [Table 1]

[0175] (Example 2): Example 2 demonstrates that even with a constant discharge current, a significant reduction in the charge current improves cycle life. The higher the discharge current / charge current ratio, the longer the cycle life.

[0176] The same cell as in Example 1 was used, except that it had an NCM622 cathode. The cell capacity was 330mAh. The cell was charged to 4.35V and discharged to 3.2V with the currents shown in Table 2 below. [Table 2]

[0177] Table 2 shows that cycle life increased with a higher discharge current / charge current ratio. The greatest effect was observed when the ratio was between 3 and 6, and the effect decreased further with higher ratios and longer charging times.

[0178] (Example 3): Example 3 shows that cycle life improved when the charging current was fixed and the discharge current was considerably high. The higher the discharge current / charging current ratio, the longer the cycle life.

[0179] The cell was the same as in Example 2, except that it used the electrolyte LiIon 1401. The cell capacity was 330mAh. The cell was charged to 4.35V and discharged to 3.2V with the currents shown in Table 3 below. [Table 3]

[0180] By changing the discharge current / charge current ratio from 1 to 4 while maintaining a constant charging current, the cycle life was dramatically improved by six times.

[0181] (Example 4): Example 4 shows that when the charging current was fixed and the discharge current was considerably high, the cycle life improved, but it was not necessarily continuous. The cell was discharged under conditions in which the discharge was periodically interrupted and then resumed for a certain period of time.

[0182] The cell was the same as in Example 3. The cell capacity was 330mAh. The cell was charged to 4.35V and discharged to 3.2V with the currents shown in Table 3 below. A charging current of 100mA was continued.

[0183] The discharge process at 400mA was not continuous. Discharge at 400mA was continued for 10 seconds, then interrupted for 30 seconds, and then resumed. This process was periodic. The cycle life data obtained from these two processes is shown in Table 4. [Table 4]

[0184] (Example 5): Example 5 demonstrated that cycle life is improved only when a high discharge current / charge current ratio is applied to a significant portion of the discharge time or discharge capacity. When high-current discharge conditions constitute only a small portion of the overall discharge time, the improvement in cycle life is not very significant.

[0185] The cell was the same as in Example 4, except that an NCM721 cathode was used. The cell capacity was 360mAh. The cell was charged to 4.4V and discharged to 3.2V.

[0186] The first portion of the above cell experienced equal charge and discharge currents of 100mA and achieved a cycle life of 43 cycles with a cutoff of 250mAh.

[0187] The second portion of the above cell underwent a two-stage discharge process: it was charged with a constant current of 100mA to 95% of its capacity at 100mA, and then discharged at 400mA to obtain the remaining 5% of its capacity.

[0188] The cycle life of these cells was 52 cycles. This was less than 9 cycles or 21% of the cycle life obtained when a high discharge current / charge current ratio of 4 was applied to 5% of the total discharge capacity. The inventors recognized and appreciated that a better cycle life could be expected if 5% of the discharge capacity obtained with a higher discharge current / charge current ratio, for example, if the average discharge rate or average discharge current during the previous discharge cycle was less than or equal to the average charge rate or average charge current during the charge cycle, and the average discharge rate or average discharge current when discharging at least 5% of the discharge capacity of the above cells during the previous discharge cycle was at least twice or four times higher than the average charge rate or average charge current during the charge cycle.

[0189] Figure 6A shows a typical high-level process 600A for discharging the above set of cells in a battery. Improvements to the typical process 600A are described in detail in the following paragraphs.

[0190] In some embodiments, a typical process 600A may include an improvement 630A in which a set of battery cells can be selectively discharged based on at least one criterion using a multiplexing switch (e.g., the multiplexing switch 112 described above). Furthermore, the multiplexing switch may be connected to two or more sets (e.g., 121, 122, 123, and / or 124) (e.g., 121A to 121C) of cells from at least one battery (e.g., 120 to 150). Each set of cells may comprise one or more cells.

[0191] In some embodiments, process 600A may then be terminated or repeated as necessary.

[0192] Figure 6B shows a typical high-level process 600B for discharging a set of battery cells. Improvements to the typical process 600B are described in detail in the following paragraphs.

[0193] In some embodiments, a typical process 600B may optionally begin in improvement 610, in which a multiplexing switch device may be used to connect the set of cells to the load in a topology adopted by the load. The battery (e.g., 120-150) may include a set of the cells (e.g., 121A-121C) (e.g., 121, 122, 123, and / or 124), each set of cells may comprise one or more cells. For example, the multiplexing switch device may connect the cells to the load in series, parallel, series / parallel, or any other suitable topology necessary to satisfy the voltage and current requirements of the load or the needs of a given application or user.

[0194] In some embodiments, a typical process 600B may then optionally proceed to improvement 620, in which at least one criterion, and / or some parameters of the criterion, may be measured or otherwise monitored in relation to the above cells of a battery or battery that has already discharged or may be in the process of discharging, in order to determine whether the criterion has been met.

[0195] For example, a sensor (e.g., 116 in Figures 1A and 1F) may measure the discharged capacity delivered at the connection between the load and the set of cells currently connected to the load, or it may measure the current of the set of cells. Alternatively or additionally, the sensor may measure any of the following: the duration of the connection (which may be at least 0.01 seconds in some embodiments), the capacity accumulated over some connection between the load and the set of cells, the voltage of the set of cells and / or at least one other set of cells, the discharge termination voltage of the set of cells, the power of the set of cells, the energy of the set of cells, the number of charge or discharge cycles of the set of cells, the impedance of the set of cells, the voltage fading rate of the set of cells while connected, the temperature of the set of cells, and the pressure of the set of cells.

[0196] In some embodiments, the criterion may include the sequence in which the cells or sets of cells are discharged. Alternatively or additionally, the criterion may be the value of a function having any of the above as parameters. According to some embodiments, the criterion does not include the number of previous discharge cycles of the set of cells.

[0197] In some embodiments, if the criteria are met, representative process 600B then proceeds to improvement 630, in which a multiplexing switch (such as the multiplexing switch 112 described above) may be used to selectively discharge the next set of cells in the battery based on the criteria. For example, if the current discharged set of cells meets any required criteria or standards, that set of cells may be disconnected, and the next set of cells may be connected as described herein (where the next set may be determined by the same or different criteria or standards described above). Alternatively, if the criteria are not met, monitoring may be continued. According to some embodiments, the connection between a single cell and a load may have a duration of at least 0.01 seconds. The inventors recognize and understand that connection durations shorter than 0.01 seconds surprisingly generate more noise than the case of 0.01 seconds, and that the electrochemistry of the cells may not be able to achieve a non-negligible level.

[0198] In some embodiments, typical process 600B then optionally proceeds to improvement 631, in which a multiplexing switch device may be used to isolate a single set of cells for discharge while other sets of cells are not discharged. For example, when a controller (e.g., 114 in Figures 1A and 1F) determines that cell 121B should be discharged, it may cause the multiplexing switch device to isolate cell 121B for discharge while cells 121A and 121C are not discharged.

[0199] In some embodiments, a typical process 600B may then optionally proceed to any of improvements 632, 634, 636, and / or 638. For example, if process 600B proceeds from improvement 631 to improvement 632, the multiplexing switch device may be used to selectively discharge the set of cells at a first speed at least twice as high as a second speed for charging the set of cells.

[0200] Alternatively or additionally, process 600B may proceed from improvement 631 to improvement 634, in which a multiplexing switch device may be used to selectively discharge the set of cells at a first speed at least four times higher than a second speed for charging the set of cells.

[0201] Alternatively or additionally, process 600B may proceed from improvement 631 to improvement 636, and the discharge of the set of cells may overlap in time, for example, by using a multiplexing switch device as described above.

[0202] Alternatively or additionally, process 600B may proceed from improvement 631 to improvement 638, during which power may continue to be supplied from the set of cells mentioned above during the switching between different sets.

[0203] Although improvements 631, 632, 634, 636, and / or 638 are shown as separate improvements in Figure 6B, it should be understood that they may actually be considered as a single unit with improvement 630.

[0204] In some embodiments, a typical process 600B may then optionally proceed to improvement 640, in which a multiplexing switch device may be used to charge the set of cells in parallel, as described above.

[0205] According to some embodiments, any number of sets of cells, including all sets of cells in a battery, battery pack, or system, may be discharged simultaneously. For example, in a battery having four cells, all four cells (or just two or three) may be discharged simultaneously, resulting in any discharge current that is desirable for the load or application and possible for the cells. Furthermore, in some embodiments, the number of cells or sets to be discharged or charged is selected based on at least one criterion, such as the discharge current for discharge. In some embodiments, the order in which the above number of cells or sets of cells are discharged or charged is selected based on at least one criterion, such as the discharge current for discharge. In some embodiments, both the number of cells or sets to be discharged or charged and the order in which they are discharged or charged are selected based on at least one criterion, such as the discharge current for discharge.

[0206] In some embodiments, process 600B may then be terminated or repeated as necessary. For example, process 600B may be repeated through any preferred number of cycles. According to some embodiments, for each cycle or for some cycles, each cell may be discharged once before any cell is discharged twice.

[0207] Figure 6C shows a typical high-level process 600C for controlling the battery pack. Improvements to the typical process 600C are described in detail in the following paragraphs.

[0208] In some embodiments, a typical process 600C may include an improvement 630C in which a switch is controlled (e.g., by a controller such as 114 above) to sequentially discharge a set of cells (e.g., 121A-121C) (e.g., 121, 122, 123, and / or 124) in a battery pack (e.g., 210) using an integrated switching control system. Furthermore, a multiplexing switch device may be connected to two or more sets of cells in the battery. Each of the above sets of cells may comprise one or more cells.

[0209] In some embodiments, process 600C may then terminate or be repeated as necessary.

[0210] Figure 6D shows a typical high-level process 600D for controlling the battery pack. Improvements to the typical process 600D are described in detail in the following paragraphs.

[0211] In some embodiments, a typical process 600D may include an improvement 630D in which a switch is controlled (by a controller such as the aforementioned 114) to discharge a set of cells (e.g., 121A-121C) (e.g., 121, 122, 123, and / or 124) in a battery pack (e.g., 210) based on a criterion, using an integrated switching control system. Furthermore, a multiplexing switch device may be connected to two or more sets of cells in the battery. Each set of cells may consist of one or more cells. In some embodiments, the criterion may include the duration of the connection between the load and the set of cells currently connected to the load, the discharge capacity delivered in the connection, and the value of a function having one or more parameters.

[0212] In some embodiments, process 600D may then be terminated or repeated as necessary.

[0213] The inventors recognize and understand that some of the embodiments described above, when implemented, may result in various improvements over the prior art. For example, in one embodiment, an active electrode area of ​​99.41 cm² is obtained from an NCMA622 cathode (BASF) having a 50 μm Li foil and a 25 μm Celgard 2325 separator filled with F9 (BASF) electrolyte containing 1 wt% lithium bis(oxalato) borate (LiBOB). 2The above-mentioned cells were fabricated. Thirteen batteries, each containing four of these cells, were assembled. The batteries were subjected to 13 charge-discharge cycle tests using several embodiments under the conditions shown in Tables 5 and 6 below. The cells within the batteries were subjected to a load of 12 kg / cm³ during the cycle tests. 2 It was held under pressure and at a temperature of 18°C. [Table 5] [Table 6]

[0214] Table 5 (Test Numbers 1-3) shows comparative examples (conducted using conventional technology), summarizing the test results when cells were connected in parallel and a charge / discharge current was applied equally to the four cells, allowing the battery to be charged and discharged at a constant current. The charge cutoff voltage was 4.35V, and the discharge cutoff voltage was 3.2V. The charge / discharge cycle was stopped when the battery capacity reached 800mAh.

[0215] Table 6 (test numbers 4-13) summarizes the test results when the cells were connected in parallel and the charge / discharge current was supplied equally to the four cells, charging the battery to 4.35V with a constant current. The discharge of these batteries was performed so that the entire battery had a constant discharge current. However, the individual cells were sequentially connected to and disconnected from the load, and only one of the four cells was supplied with a discharge current pulse at a time. When this pulse ended, the next cell was connected and the previous cell was disconnected. Discharge pulses were sequentially supplied to the cells for a certain pulse duration or until the discharge voltage reached 3.2V (e.g., cell numbers 1, 2, 3, 4, 1, 2, 3, 4, etc.). Test numbers 4, 8, and 12 performed full cell discharge with a single pulse. In the other tests, partial cell discharge was performed with single pulses lasting 0.1 seconds, 1 second, and 10 seconds. The charge / discharge cycle was stopped when the battery capacity reached 800mAh.

[0216] Figure 7A corresponds to test number 13 and shows the battery voltage profile at the start of the 10-second pulse discharge for the first 240 seconds, while Figure 7B shows the complete discharge profile down to a voltage of 3.2V. In Figure 7A, the above cell numbers affected by the 10-second 300mA pulse in a repeating sequence for the first 80 seconds are shown.

[0217] Referring again to Tables 5 and 6, the inventors recognize and understand that sequentially applying the total discharge current of the battery to a portion of the battery cells (Table 6) dramatically improves cycle life compared to the uniform current distribution across all battery cells as has been done in the prior art (Table 5). This improvement in cycle life can be up to six times, and the inventors recognize that it may be a function not only of the charge-discharge rate but also of the discharge pulse duration. Figure 7C, showing the battery cycle life as a function of pulse duration at two charge-discharge rates (corresponding to test numbers 4-11), shows that cycle life can be particularly improved when the pulse duration is longer than 0.1 seconds and around 10 seconds. The inventors have recognized and understood that, as shown in Figure 7C and as not expected based on prior art experience, the improvement in battery cycle life described herein is possible even when using several embodiments during partial discharge. Furthermore, even if non-uniform, the full capacity of all cells can be utilized in several embodiments.

[0218] In some embodiments, the methods described above with reference to Figures 4A to 6 should be understood to be modifiable in any of the many methods. For example, in some embodiments, the steps of the methods described above may be performed in a different order than those described, the methods may include further steps not described above, and / or the methods may not include all of the steps described above.

[0219] It should be further understood from the foregoing description that some embodiments may be carried out using computing devices. Figure 8 shows a general-purpose computing device in system 800 in the form of computer 810, which may be used to carry out some embodiments, such as one of the controllers described above (e.g., 114).

[0220] In computer 810, the components include, but are not limited to, a processing unit 820, system memory 830, and a system bus 821 that connects various system components, including system memory, to the processing unit 820. The system bus 821 may be any of several types of bus structures, including a memory bus or memory controller, peripheral buses, and local buses using any of various bus architectures. Examples of such architectures, though not limited to them, include the Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus, also known as the Mezzanine bus.

[0221] Computer 810 typically includes various computer-readable media. Computer-readable media may be any available media accessible by computer 810, including both volatile and non-volatile media, and removable and non-removable media. By example, but not limited to, computer-readable media may include computer storage media and computer communication media. Computer storage media include both volatile and non-volatile, removable and non-removable media, implemented in any method or technique for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk (DVD) or other optical disk storage devices, magnetic cassettes, magnetic tapes, magnetic disk storage devices or other magnetic storage devices, or any one or more other media accessible by computer 810 that can be used to store desired information. Communication media typically include any information distribution media that embody computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other carrier mechanisms. The term "modulated data signal" refers to a signal in which one or more of its characteristics are set or modified in a manner that encodes information within the signal. Examples of communication media, though not limited to them, include wired media such as wired networks or direct wired connections, and wireless media such as acoustic, RF, and infrared. Any combination of the above is also included within the scope of computer-readable media.

[0222] System memory 830 includes computer storage media in the form of volatile and / or non-volatile memory, such as read-only memory (ROM) 831 and random access memory (RAM) 832. The basic input / output system (BIOS) 833, which contains basic routines that help transfer information between elements within the computer 810, such as during startup, is typically stored in ROM 831. RAM 832 typically contains data and / or program modules that are immediately accessible to and / or currently being manipulated by the processing unit 820. As an example, but not an limitation, Figure 8 shows the operating system 834, application programs 835, other program modules 839, and program data 837.

[0223] Computer 810 may include other removable / non-removable, volatile / non-volatile computer storage media. For illustrative purposes only, Figure 8 shows a hard disk drive 841 that reads from or writes to a non-removable, non-volatile magnetic medium, a magnetic disk drive 851 that reads from or writes to a removable, non-volatile magnetic disk 852, and an optical disk drive 855 that reads from or writes to a removable, non-volatile optical disk 859, such as a CD-ROM or other optical medium. Other removable / non-removable, volatile / non-volatile computer storage media that may be used in the exemplary computing system include, but are not limited to, magnetic tape cassettes, flash memory cards, digital multipurpose disks, digital videotapes, solid-state RAM, and solid-state ROM. The hard disk drive 841 is typically connected to the system bus 821 by a non-removable memory interface, such as interface 840, while the magnetic disk drive 851 and optical disk drive 855 are typically connected to the system bus 821 by a removable memory interface, such as interface 850.

[0224] As mentioned above, the drives and associated computer storage media shown in Figure 8 store computer-readable instructions, data structures, program modules, and other data for computer 810. In Figure 8, for example, the hard disk drive 841 is shown as storing the operating system 844, application program 845, other program modules 849, and program data 847. Note that these components may be the same as or different from the operating system 834, application program 835, other program modules 839, and program data 837. The operating system 844, application program 845, other program modules 849, and program data 847 are given different numbers here to illustrate that they are at least different copies. The user may input commands and information to computer 810 via input devices such as the keyboard 892 or a pointing device 891, which generally refers to a mouse, trackball, or touchpad. Other input devices (not shown) include microphones, joysticks, gamepads, satellite receivers, and scanners. These and other input devices are often connected to the processing unit 820 via a user input interface 590 coupled to the system bus, but may also be connected via other interfaces and bus structures such as parallel ports, game ports, or Universal Serial Bus (USB). A monitor 891 or other type of display device is also connected to the system bus 821 via an interface such as a video interface 890. In addition to the monitor, the computer may include other peripheral output devices such as speakers 897 and printers 899, which may be connected via an output peripheral interface 895.

[0225] Computer 810 may operate in a networked environment using logical connections to one or more remote computers, such as remote computer 880. The remote computer 880 may be a personal computer, server, router, network PC, peer device, or other common network node, typically including many or all of the elements described above in relation to computer 810, although only the memory storage device 881 is illustrated in Figure 8. The logical connections shown in Figure 8 include a local area network (LAN) 871 and a wide area network (WAN) 873, but may include other networks. Such network environments are commonplace in offices, enterprise-scale computer networks, intranets, and the internet.

[0226] When used in a LAN network environment, computer 810 is connected to LAN 871 via a network interface or adapter 870. When used in a WAN networking environment, computer 810 typically includes a modem 872 or other means for establishing communication over a WAN 873, such as the Internet. The modem 872, which may be internal or external, may be connected to the system bus 821 via a user input interface 890 or other preferred mechanism. In a network environment, program modules, or parts thereof, shown in relation to computer 810 may be stored in a remote memory storage device. As an example, but not an limitation, Figure 8 shows a remote application program 885 residing in memory device 881. The shown network connections are illustrative, and other means may be used to establish communication links between computers.

[0227] The embodiments may be embodied as a computer-readable storage medium (or multiple computer-readable media) (e.g., computer memory, one or more floppy disks, compact discs (CDs), optical discs, digital video discs (DVDs), magnetic tape, flash memory, circuit configurations in field programmable gate arrays or other semiconductor devices, or other tangible computer storage media) encoding one or more programs that, when executed on one or more computers or other processors, perform methods for carrying out the various embodiments described above. As will be apparent from the embodiments described above, the computer-readable storage medium may retain information for a time sufficient to provide computer-executable instructions in a non-transitory form. Such a computer-readable storage medium may be transportable so that the programs stored therein can be loaded (or read) into one or more different computers or other processors to carry out the various aspects of the invention described above. As used herein, the term “computer-readable storage medium” includes only tangible machines, mechanisms, or devices from which a computer can read information. Alternatively or additionally, some embodiments may be embodied as computer-readable media other than computer-readable storage media. Examples of computer-readable media other than computer-readable storage media include transient media such as propagating signals.

[0228] Although some aspects of the invention have been described and illustrated herein, those skilled in the art will readily envision various other means and / or structures for performing the functions and / or obtaining the results and / or one or more of the advantages described above, and such variations and / or modifications are each considered to be within the scope of the invention. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be illustrative, and that the actual parameters, dimensions, materials, and / or configurations will depend upon the particular application for which the teachings of the invention are used. Those skilled in the art can recognize, or ascertain, with little experimentation, many equivalents to the various aspects of the invention described herein. Accordingly, the foregoing aspects are presented by way of example only and it should be understood that the invention may be practiced otherwise than as specifically described within the scope of the appended claims and their equivalents. The invention relates to the individual features, systems, articles, materials, kits, and / or methods described herein. Also, combinations of two or more such features, systems, articles, materials, kits, and / or methods are included within the scope of the invention provided such features, systems, articles, materials, kits, and / or methods do not mutually conflict.

[0229] As used in the specification and claims, the indefinite articles "a" and "an" should be understood to mean "at least one" unless explicitly indicated otherwise.

[0230] As used in the specification and in the claims, the phrase "and / or" should be interpreted to mean "either or both" of the conjoined elements, i.e., elements that in some cases coexist and in other cases exist separately. Unless explicitly stated otherwise, other elements may optionally be present in addition to those specifically identified, whether or not related to those specifically identified by the "and / or" clause. Thus, as a non-limiting example, "A and / or B", when used in conjunction with an open-ended term such as "comprising", in one aspect means A without B (optionally including elements other than B); in another aspect means B without A (optionally including elements other than A); in yet another aspect means both A and B (optionally including other elements); and so on.

[0231] As used in the specification and in the claims, "or" should be interpreted to have the same meaning as "and / or" as defined above. For example, when separating the items in a list, "or" or "and / or" is inclusive, i.e., should be interpreted to mean at least one, including more than one, of the many elements or list of elements, optionally including further items not listed in the list. Only explicitly stated items, e.g., "only one of... " or "exactly one of... ", or "consisting of... " when used in the claims, mean exactly one of the many elements or list of elements. In general, the term "or" as used herein is to be interpreted as indicating exclusive alternatives (i.e., "one or the other but not both") only when preceded by terms such as "either", "one of... ", "only one of... " or "exactly one of... ". "Consisting essentially of... " when used in the claims has its ordinary meaning as used in the field of patent law.

[0232] As used in the specification and claims, the phrase “at least one” relating to a single list of one or more elements should be understood to mean at least one element selected from one or more elements in the list of elements, but not necessarily including at least one of each element specifically listed in the list of elements, nor necessarily excluding combinations of elements in the list of elements. This definition also allows for the possibility that there may be elements other than those specifically identified in the list of elements, meaning whether or not they are related to those specifically identified elements. Therefore, as a non-restrictive example, “at least one of A and B” (equivalently, “at least one of A or B,” or equivalently, “at least one of A and / or B”) can mean, in one embodiment, at least one A (including any element other than B) in which there is no B, which includes any more than one; in another embodiment, at least one B (including any element other than A) in which there is no A, which includes any more than one; and in yet another embodiment, at least one A and at least one B (including any other element) which includes any more than one; and so on.

[0233] In the claims as well as in the specification, all such transitional clauses as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” and “holding” are understood to be open-ended, meaning they include but are not limited to them. Only the transitional clauses “consisting of” and “essentially consisting of” are closed or semi-closed transitional clauses, as described in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03. [Explanation of Symbols]

[0234] 100 ... The above cell management system 112 … Multiplexing switch device 114 ... Controller 116, 360 ... sensors 120, 130, 140, 150…Battery 121-124, 131-132, 141-142, 151-152... The above cell sets 121A~121C, 321A~321C… Electrochemical cells 210… Battery pack 218… Switching control system 300 ... Battery Management System 310 ... Cathode 312 … Anode 314 … electrolyte 316 ... Storage structure 318A, 318B… Surface of the storage structure 320 ... Cathode active surface 321-325 ... Multi-cell block 322 … Anode active surface 326… Battery cell block arrangement and balance switch configuration 327… Battery management microcontroller 328 … Battery system interface 329…Battery power terminal 332 ... Circuit board 334… Pressure distributor 336… Pressure Transmitter 340 ... Surface of the pressure distributor 342 … Surface of an electrochemical cell

Claims

1. Electrochemical cells containing electrochemically active lithium metals; and At least one controller configured to control the cell such that, in at least a portion of the charging process, the cell is charged at a charging rate or charging current lower than the discharge rate or discharge current of at least a portion of the previous discharging process. An electrochemical cell management system equipped with the following features.

2. An electrochemical cell comprising an electrochemically active lithium metal, and at least one controller Equipped with, The aforementioned at least one controller, The system monitors at least a portion of the discharge history of the cell stored in memory, and Based on the portion of the cell's discharge history stored in memory, the system induces a discharge of at least 5% of the cell's capacity at a discharge rate or discharge current higher than the average charge rate or average charge current used to charge the cell in the previous charging cycle, and / or controls the cell's charge rate or charge current to be lower than the discharge rate or discharge current of at least a portion of the previous discharge cycle. An electrochemical cell management system configured as follows.

3. An electrochemical cell containing an electrochemically active lithium metal, and Before and / or after the charging process of the cell, at least one controller configured to induce a discharge of at least 5% of the cell's capacity at a discharge rate or discharge current higher than the charging rate or charging current used to charge the cell. Equipped with, An electrochemical cell management system wherein at least one controller is configured to induce the discharge of the cell at a first speed or a first current, through at least 5% of the cell's capacity, immediately before the start of a charging step of the cell, which charges the cell at a slower rate or current than the first speed or the first current.

4. The electrochemical cell management system according to claim 1, wherein the discharge rate or discharge current is at least twice as high as the charging rate or charging current.

5. The electrochemical cell management system according to claim 1, wherein the discharge rate or discharge current is four times higher than the charging rate or charging current.

6. The average discharge rate or average discharge current during the previous discharge process is less than or equal to the average charging rate or average charging current during the charging process, and The electrochemical cell management system according to claim 1, wherein the average discharge rate or average discharge current when discharging at least 5% of the cell's discharge capacity during the previous discharge process is at least twice as high as the average charging rate or average charging current during the charging process.

7. The electrochemical cell management system according to claim 6, wherein the average discharge rate or average discharge current when discharging at least 5% of the cell's discharge capacity during the previous discharge process is four times higher than the average charging rate or average charging current during the charging process.

8. The electrochemical cell management system according to claim 1 or 3, wherein the at least one controller is configured to control the charging of the cell based on at least one characteristic of the cell.

9. The electrochemical cell management system according to claim 8, wherein the at least one controller is configured to monitor at least one characteristic of the cell.

10. The electrochemical cell management system according to claim 1 or 2, wherein the at least one controller is configured to induce the discharge of the cell.

11. The electrochemical cell management system according to claim 9, wherein at least one characteristic of the cell includes at least a portion of the discharge history of the cell stored in memory.

12. The electrochemical cell management system according to claim 9, wherein at least one characteristic of the cell includes at least one morphological characteristic of the cell.

13. The electrochemical cell management system according to any one of claims 1 to 3, wherein the at least one controller is configured to induce the discharge of the cell at the end of the cell discharge process.

14. The electrochemical cell management system according to any one of claims 1 to 3, wherein the at least one controller is configured to induce the discharge of the cell during the discharge process and / or at the end of the charging process of the cell.

15. The electrochemical cell management system according to claim 1 or 2, wherein the at least one controller is configured to induce the discharge of the cell before and / or after the charging process of the cell.

16. The electrochemical cell management system according to any one of claims 1 to 3, wherein the at least one controller comprises at least one processor.

17. The electrochemical cell management system according to any one of claims 1 to 3, wherein the cell contains a lithium metal electrode active material.

18. The at least one characteristic includes at least one morphological characteristic of the cell, which includes at least one rate of increase of the cell's thickness and / or pressure, and The electrochemical cell management system according to claim 9, wherein the at least one controller is configured to induce the discharge of the cell and / or control the charging rate or charging current of the cell based on at least one rate of increase of the cell's thickness and / or pressure.

19. The electrochemical cell management system according to claim 9, wherein the at least one controller is configured to induce the discharge of the cell at the end of the discharge process of the cell based on at least one characteristic of the cell.

20. The electrochemical cell management system according to claim 9, wherein the at least one controller is configured to induce the discharge of the cell during the discharge process of the cell and / or at the end of the charging process of the cell, based on at least one characteristic of the cell.

21. The electrochemical cell management system according to claim 9, wherein the at least one controller is configured to induce the discharge of the cell before and / or after a charging step of the cell, based on at least one characteristic of the cell.

22. The electrochemical cell management system according to any one of claims 9 and 11, wherein the at least one controller is configured to induce the discharge of the cell at a first rate or a first current, through at least a threshold capacity of the cell, immediately before the start of a charging step of the cell which charges the cell at a slower rate or a first current than the first rate or a first current, based on at least one characteristic of the cell.

23. The electrochemical cell management system according to any one of claims 1 to 3, wherein the at least one controller is configured to induce the discharge of the cell while the cell is connected to a charging device.

24. The aforementioned at least one controller is Higher than the average discharge rate or average discharge current of the previous discharge process, Higher than the average charging speed or average charging current of the previous charging cycle. The electrochemical cell management system according to any one of claims 1 to 3, configured to induce a discharge of at least 5% of the cell's capacity at a speed or current which is at least one of the following:

25. Controlling an electrochemical cell containing an electrochemically active lithium metal such that, in at least part of the charging process, the electrochemical cell is charged at a charging rate or charging current lower than the discharge rate or discharge current of at least part of the previous discharge process. An electrochemical cell control method including the following.

26. Before and / or after the charging process of the electrochemical cell, induce a discharge of at least 5% of the capacity of the electrochemical cell at a discharge rate or discharge current higher than the charging rate or charging current used to charge the electrochemical cell containing an electrochemically active lithium metal. Includes, An electrochemical cell management method comprising inducing the discharge of the cell at a first speed or first current, after at least 5% of the cell's capacity, immediately before the start of a charging process for the cell in which the cell is charged at a slower speed or a slower current than the first speed or the first current.

27. To monitor at least a portion of the discharge history of the electrochemical cell stored in memory, and Based on the portion of the cell's discharge history stored in memory, the charging speed or charging current of the cell is controlled to induce a discharge of at least 5% of the cell's capacity at a discharge speed or discharge current higher than the average charging speed or average charging current used to charge the cell in the previous charging process, and / or to be lower than the discharge speed or discharge current of at least a portion of the previous discharging process. Includes, An electrochemical cell management method in which the cell contains a lithium metal electrode active material.

28. The electrochemical cell management method according to claim 25, wherein the discharge rate or discharge current is at least twice as high as the charging rate or charging current.

29. The average discharge rate or average discharge current during the previous discharge process is less than or equal to the average charging rate or average charging current during the charging process, and The electrochemical cell management method according to any one of claims 25 to 28, wherein the average discharge rate or average discharge current at the time of discharge of at least 5% of the cell's discharge capacity during the previous discharge process is at least twice as high as the average charging rate or average charging current during the charging process.

30. An electrochemical cell management method according to any one of claims 25 to 26, comprising controlling the charging of the cell based on at least one characteristic of the cell.

31. The aforementioned at least one characteristic is, At least a portion of the discharge history of the cell, and At least one morphological characteristic of the cell The electrochemical cell management method according to claim 30, comprising at least one of the following.

32. The electrochemical cell management method according to claim 31, comprising monitoring at least one characteristic of the cell.

33. An electrochemical cell management method according to any one of claims 25 and 27, comprising inducing discharge of the cell.

34. The electrochemical cell management method according to claim 33, comprising inducing the discharge of the cell at the end of the discharge process of the cell.

35. The electrochemical cell management method according to claim 33, comprising inducing the discharge of the cell before and / or after the charging process of the cell.

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