Energy storage unit comprising a battery module and method for managing such an energy storage unit

Abstract

The invention relates to a battery module (10), comprising a module management system (11) and at least one battery cell (30) having a cell voltage. The at least one battery cell (30) is capable of assuming: a first operating mode (Mod1) in which the battery cell (30) is discharged, and a second operating mode (Mod2) in which the battery cell (30) is not discharged. The module management system (11) is configured to selectively place the cell voltage (30) in one of the operating modes (Mod1, Mod2) depending on the cell voltage. Finally, the invention relates to a method for managing such an energy storage unit (1).

Description

Technical Field

[0001] The present invention relates to a battery module including a module management system.

[0002] The invention also relates to an energy storage unit comprising at least one such battery module and a battery management system.

[0003] The invention also relates to a method for managing an energy storage unit. Background Art

[0004] The present invention is applicable to the field of electrical energy storage, in particular to the field of batteries. More and more systems or devices use batteries to store electrical energy so that it can be used to operate the device or system. In particular, vehicles such as cars, buses or bicycles increasingly carry batteries to provide electric propulsion or operate on-board auxiliary equipment. Batteries can also be used to power electrical grids, such as residential grids or "V2G" ("Vehicle-To-Grid") networks.

[0005] The result of these varying energy requirements is a highly variable demand for electrical power. To address this demand, different sizes and active materials are used at different levels of the battery. For example, a first active material can be used to respond to a power bias, such as during startup or for overtaking the vehicle carrying the battery, or for servicing a "V2G" network. Alternatively, a second active material can be used, intended for use during an energy bias—that is, a bias intended to last longer than the aforementioned power bias—and aimed, for example, at ensuring autonomous vehicle functionality or for servicing an erasable V2G network.

[0006] It is known from the prior art to use two different types of active materials, that is, two types of chemical substances, to form a battery cell. Each type of battery cell can be grouped together, for example, in modules or module groups and controlled by a dedicated management system, also known as a "BMS (Battery Management System)". A common management system, also known as a "master BMS", is used to control the entire battery. The total storage unit thus consists of one or more cells, each of which is specialized for a specific energy requirement. The management system is then configured to bias one or the other of the cells.

[0007] These solutions are desirable because they allow for a specific response to the power demands of the electric motors or auxiliary equipment ultimately installed on the vehicle. However, these solutions require the installation of several battery modules and several battery management systems within the vehicle, which increases the vehicle's mass and, consequently, its overall energy consumption. Furthermore, implementing all the necessary battery components increases system complexity, thereby increasing the vehicle's overall cost. Finally, depending on the user's use of the storage system, some batteries may be biased more frequently and more intensely than others, resulting in unequal aging of each cell and a tendency to cause the storage system to become obsolete more quickly. Summary of the Invention

[0008] The object of the present invention is to propose a solution that responds to all or part of the aforementioned problems.

[0009] This object can be achieved by providing a battery module comprising a module management system and at least one battery cell having a state of charge characterized by at least a cell voltage.

[0010] The at least one battery cell includes at least one electrode comprised of at least one active material, the at least one active material having a first voltage tray characterized by a first voltage range in a characteristic curve of the active material relating specific capacitance to voltage, and a second voltage tray characterized by a second voltage range in the characteristic curve.

[0011] The at least one battery cell can be in:

[0012] - a first operating mode in which the battery cell is discharged,

[0013] A second operating mode in which the battery cell is not discharged.

[0014] The module management system is configured to decide to selectively place the battery cell in an operation mode selected from the first and second operation modes based on a cell voltage of the at least one battery cell.

[0015] That is, the module management system uses the cell voltage of the at least one battery cell to decide whether to place the battery cell in the first operating mode and / or to decide whether to place the battery cell in the second operating mode. Therefore, it can be understood that the cell voltage of the battery cell serves as a decision criterion for the module management system to selectively place the battery cell in one of the first and second operating modes.

[0016] In other words, the module management system can, based on its state of charge, determine the cell voltage and decide to discharge at least one battery cell (according to the first operating mode) or not to discharge at least one battery cell (according to the second operating mode). Advantageously, the module management system can select to discharge at least one battery cell based on the value of its cell voltage relative to the first and second voltage ranges.

[0017] The previously described arrangement makes it possible to propose a battery module in which each battery cell can be discharged based on its state of charge. Advantageously, the presence of at least one active material with two different voltage plates makes it possible to bias the battery cells differently depending on the voltage plate on which the active material is placed during the selection of the operating mode.

[0018] The battery module may further have one or more of the following characteristics, either individually or in combination.

[0019] According to one embodiment, the cell voltage is the voltage measured across the corresponding battery cell.

[0020] According to one embodiment, the active material formed by the electrodes of the battery cell has an olivine-type structure.

[0021] According to one embodiment, the olivine-type structure corresponds to the chemical formula LiFe z Y 1-z PO4, where 0 < z < 1, and where Y is a chemical element selected from the group including manganese, nickel, and cobalt.

[0022] Advantageously, the value of z can be changed by varying the molar fraction of iron atoms or element Y atoms. In this way, the length of the first voltage plate and / or the second voltage plate can be changed.

[0023] According to one embodiment, the module management system is configured to: based on the number of electrons that can be released by biasing the electrochemically active sites corresponding to the type characteristics of one of the battery plates, decide to place the battery module in the first or second operating mode.

[0024] In particular, when the structure of the active material is an olivine-type structure, the active material may have a first voltage disk corresponding to the electrochemical potential of an iron atom and a second voltage disk corresponding to the electrochemical potential of an atom Y (such as manganese). In this case, when the cell voltage of the battery cell corresponds to a voltage included in the first voltage range, the battery module may decide to place the battery cell in the first operating mode in response to a demand for high electric power, which is particularly suitable for structures including iron atoms. Alternatively, when the cell voltage of the battery cell corresponds to a voltage included in the second voltage range, the battery module may decide to place the battery cell in the first operating mode in response to a demand for electric energy for a sustained period of time, which is particularly suitable for structures including manganese atoms. Therefore, advantageously, the module management system is able to selectively place the battery cell in the first operating mode or the second operating mode depending on the type of energy demand (for a sustained period of time or for a short time interval).

[0025] According to one embodiment, the first voltage range is relative to the voltage supplied by the electrochemical couple Li + The reference potential of the electrochemical couple Li is comprised between 3.2 V and 3.6 V, more particularly with respect to the + The reference potential of the Li / Li is comprised between 3.3 V and 3.5 V, while the second voltage range is relative to the potential of the electrochemical couple Li + The reference potential of the Li / Li pair is comprised between 3.7 V and 4.3 V, more particularly with respect to the electrochemical couple Li + The reference potential of the CMOS / Li composition is comprised between 3.8V and 4.1V.

[0026] According to one embodiment, the module management system is configured to measure the cell voltages of the battery cells.

[0027] According to one embodiment, the module management system is configured to measure the state of health level of the battery cell, and the module management system is further configured to decide to selectively place the battery cell in an operating mode selected from the first and second operating modes based on the state of health level of the battery cell.

[0028] It is therefore well understood that the state of health level is a decision criterion for placing the battery cell into one of the first and second operating modes.

[0029] According to one embodiment, a battery module includes a plurality of battery cells, wherein each battery cell has a single cell voltage that is different from the cell voltages of other battery cells, and the module management system is configured to: decide to selectively place each battery cell of the plurality of battery cells in an operating mode selected from the first and second operating modes based on the single cell voltage of the battery cell.

[0030] According to one embodiment, the module management system is configured to decide to selectively place each battery cell in an operating mode selected from the first and second operating modes according to a strategy algorithm recorded in a memory of the module management system.

[0031] The object of the present invention can also be achieved by providing an energy storage unit, which includes at least two battery modules of the above-mentioned type, and a battery management system, which is configured to control each of the module management systems of the at least two battery modules based on the demand for power from an external system.

[0032] Finally, the objects of the present invention can be achieved by implementing a method for managing an energy storage unit, which includes a plurality of battery modules whose number is greater than or equal to 2, wherein each battery module of the plurality of battery modules includes a module management system and at least one battery cell having a charge state characterized by at least a cell voltage.

[0033] In the management method, the at least one battery cell includes at least one electrode composed of at least one active material, the at least one active material having a first voltage disk and a second voltage disk, the first voltage disk being characterized by a first voltage range in a characteristic curve of the active material relating specific capacitance to voltage, and the second voltage disk being characterized by a second voltage range in the characteristic curve. The management method comprises:

[0034] - the step of receiving a demand for power from an external system;

[0035] - a step of determining, for at least one of the at least one battery cell, a cell voltage of the battery cell;

[0036] - A step of selectively biasing the battery cell in a first operating mode in which the battery cell is discharged or in a second operating mode in which the battery cell is not discharged, depending on the power demand and the cell voltage of the battery cell.

[0037] The arrangement described above makes it possible to propose a battery management method capable of placing the battery cells in a voltage state depending on their cell voltage and the power demand from the external system. Thus, advantageously, given the presence of two voltage levels for the active materials constituting the cell electrodes, the battery cells can be selectively biased depending on the voltage level in which they are placed at a given time.

[0038] The management method may also have one or more of the following characteristics, alone or in combination.

[0039] According to one embodiment, the external system that generates a demand for power is an external motorized system.

[0040] According to one embodiment, the module management system is configured to measure the cell voltage of a battery cell, and the step of determining the cell voltage includes measuring the cell voltage of the battery cell.

[0041] According to one embodiment, the management method is implemented by the module management system.

[0042] According to one embodiment, the active material constituting the electrodes of the battery cell has an olivine-type structure.

[0043] According to one embodiment, the olivine-type structure corresponds to the chemical formula LiFe z Y 1-z PO4, where 0 < z < 1, and where Y is a chemical element selected from the group including manganese, nickel, and cobalt.

[0044] Advantageously, the value of z can be changed by changing the molar fraction of iron atoms or element Y atoms. In this way, the length of the first voltage plate and / or the second voltage plate can be changed.

[0045] In particular, when the structure of the active material is an olivine-type structure, the active material can have a first voltage plate corresponding to the electrochemical potential of iron atoms and a second voltage plate corresponding to the electrochemical potential of atom Y (such as manganese). In this case, when the cell voltage of the battery cell corresponds to a voltage included in the first voltage range, the step of biasing the battery cell can enable the battery cell to be placed in the first operating mode in response to a demand for high electrical power, which is particularly suitable for structures including iron atoms. Alternatively, when the cell voltage of the battery cell corresponds to a voltage included in the second voltage range, the step of biasing the battery cell can enable the battery cell to be placed in the first operating mode in response to a demand for electrical energy over a duration, which is particularly suitable for structures including manganese atoms. Thus, advantageously, the management method is capable of selectively placing the battery cell in the first operating mode or the second operating mode depending on the type of energy demand (over a duration or in a short time interval).

[0046] According to one embodiment, the first voltage range is included between 3.2 V and 3.6 V with respect to the reference potential constituted by the electrochemical couple Li + / Li, more particularly between 3.3 V and 3.5 V with respect to the reference potential constituted by the electrochemical couple Li + / Li, and where the second voltage range is included between 3.7 V and 4.3 V with respect to the reference potential constituted by the electrochemical couple Li + / Li, more particularly between 3.8 V and 4.1 V with respect to the reference potential constituted by the electrochemistry.

[0047] According to one embodiment, the management method further comprises the steps of comparing the demand for power with a predetermined high threshold power, and comparing the demand for power with a predetermined low threshold power, the biasing step further comprising the steps of:

[0048] placing the battery cell in the first operating mode if the cell voltage of the battery cell corresponds to a voltage included in the first voltage range and the demand for power is greater than or equal to the high threshold power;

[0049] placing the battery cell in the first operating mode if the cell voltage of the battery cell corresponds to a voltage included in the second voltage range and the power demand is strictly included between the high threshold power and the low threshold power;

[0050] - Otherwise, placing the battery cell in the second operating mode.

[0051] According to one embodiment, when the battery cells are fully charged, the high threshold power corresponds to the power required to fully discharge all the battery cells within one hour.

[0052] According to one embodiment, the low threshold power is equal to 0W

[0053] According to one embodiment, the management method is implemented for each battery cell of at least one battery cell. In other words, if a battery module among a plurality of battery modules includes a plurality of battery cells, the management method can be implemented for each battery cell of the plurality of battery cells.

[0054] According to one embodiment, a battery module among the plurality of battery modules includes a plurality of battery cells greater than or equal to 2, and the biasing step may further include the following steps:

[0055] placing the battery cell in the first operating mode if the cell voltage of the battery cell corresponds to a voltage included in the first voltage range, the power demand is strictly included between the upper threshold power and the lower threshold power, and none of the other battery cells of the battery module have a cell voltage corresponding to a voltage included in the second voltage range;

[0056] -Placing the battery cell in the first operating mode when the cell voltage of the battery cell corresponds to a voltage included in the second voltage range and the power demand is greater than or equal to the high threshold power, and none of the other battery cells of the battery module have a cell voltage corresponding to a voltage included in the first voltage range.

[0057] According to one embodiment, the management method may include a step of transmitting discharge information. For example, the step of transmitting discharge information may include transmitting the discharge information to the user interface when the cell voltages of all battery cells of a battery module of the plurality of battery modules are below a minimum cell voltage. For example, the minimum cell voltage may correspond to a state of charge, that is, the amount of energy remaining in the battery, which may be less than 10%, or more specifically, less than 5%.

[0058] According to one embodiment, the management method further comprises a step of measuring a state-of-health level of at least one battery cell, the biasing step being performed in dependence on the state-of-health level of the battery cell.

[0059] According to an embodiment, the module management system is configured to measure the state-of-health level of at least one battery cell during the step of measuring the state-of-health level.

[0060] According to one embodiment, the battery module includes a plurality of battery cells, wherein each battery cell has a single cell voltage different from the cell voltages of other battery cells, and the biasing step is implemented for all or part of the plurality of battery cells according to power requirements and the single cell voltage of each battery cell.

[0061] According to one embodiment, a plurality of battery modules, the number of which is greater than or equal to 2, is divided into a first group of battery modules and a second group of battery modules, each group of battery modules including at least one of the plurality of battery modules, the energy storage unit further including a battery management system configured to control each module management system, the management method including the step of selecting a group of battery modules from the first and second groups of battery modules, wherein only one group of the first group of battery modules or the second group of battery modules implements the biasing step.

[0062] According to one embodiment, the management method is implemented by a battery management system.

[0063] According to one embodiment, the management method further comprises the following steps implemented by the battery management system:

[0064] - a step of receiving a state-of-health level of a first group of battery modules;

[0065] - a step of receiving a state of health level of a second group of battery modules;

[0066] Then, a step of selecting a group of modules is performed based on the health status of the first and second groups of battery modules.

[0067] According to one embodiment, each module management system is configured to measure the health status level of a battery module included in an energy storage unit, and the management method includes:

[0068] - a step of determining a state of health level of at least one battery module of the first group of battery modules, the step being performed on each battery module of the first group of battery modules by each module management system of the first group of battery modules;

[0069] - a step of determining a state of health level of at least one battery module of the second group of battery modules, the step being performed on each battery module of the second group of battery modules by each module management system of the second group of battery modules;

[0070] - A step of transmitting said state of health determined by said module management system to a battery management system.

[0071] According to one embodiment, determining the state of health of at least one battery module of the first and / or second battery modules comprises measuring the temperature of the at least one battery module of the first and / or second battery modules.

[0072] According to one embodiment, the step of determining the health level state of at least one battery module of the first group of battery modules and / or the second group of battery modules includes: measuring the cell voltage of each battery cell included in the at least one battery module of the first group of battery modules and / or the second group of battery modules.

[0073] According to one embodiment, the step of determining the health level state of at least one battery module of the first group of battery modules and / or the second group of battery modules includes: measuring one or more parameters, which are included in the group consisting of temperature, internal resistance of battery cells, voltage measured across one or more battery modules, and the number of charge / discharge cycles performed by the battery cells constituting the at least one battery module.

[0074] According to one embodiment, the step of determining the state of health level of at least one battery module of the first group of battery modules and / or the second group of battery modules is performed by determining an average state of health level of each battery cell constituting the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Other aspects, objects, advantages and characteristics of the present invention will better appear on reading the following detailed description of preferred embodiments thereof, given by way of non-limiting examples, and with reference to the accompanying drawings, in which:

[0076] Figure 1 is a schematic diagram of an energy storage unit according to a specific embodiment of the present invention.

[0077] Figure 2 is a characteristic curve relating specific capacitance of an active material constituting a battery cell electrode to voltage according to a specific embodiment of the present invention.

[0078] Figure 3 is a schematic diagram showing cell voltages of battery cells according to certain embodiments of the present invention.

[0079] Figure 4 is a schematic diagram of a management method according to a specific embodiment of the present invention.

[0080] Figure 5 is a schematic diagram of certain steps of a management method according to another specific embodiment of the present invention.

[0081] Figure 6 is a schematic diagram of a policy algorithm that may be used in a management method according to certain embodiments of the present invention. DETAILED DESCRIPTION

[0082] In the drawings and the remainder of the description, the same reference numerals represent identical or similar elements. In addition, different elements are not represented to scale to facilitate the clarity of the drawings. In addition, different embodiments and modifications are not mutually exclusive and may be combined with each other.

[0083] like Figure 1 As shown, the present invention first relates to a battery module 10 comprising a module management system 11 and at least one battery cell 30. The present invention also relates to an energy storage unit 1 comprising at least two battery modules 10 and a battery management system 3 configured to control each of the module management systems 11 of the at least two battery modules 10 according to a demand for power from an external system, such as a motorization system. Figure 1 In particular, a specific embodiment is shown in which the energy storage unit 1 includes a plurality of battery modules 10, the number of which is greater than or equal to 2, for example, equal to 5. The battery modules 10 are divided into a first group of battery modules Gr1 and a second group of battery modules Gr2, each of which includes at least one battery module 10 from the plurality of battery modules 10. According to the illustrated embodiment, the first group of battery modules Gr1 includes one battery module 10, and the second group of battery modules Gr2 includes four battery modules 10. It goes without saying that the number of battery modules 10 in each group of battery modules may be higher or lower than in this example, and may be similar between the groups of battery modules Gr1 and Gr2.

[0084] As previously mentioned, each battery module 10 includes a module management system 11 and at least one battery cell 30. The module management system 11 may include a memory 12 in which a strategy algorithm may be recorded. Alternatively, the battery management system 3 may be configured to control one or more module management systems 11, particularly using a strategy algorithm recorded in the battery management system's memory 2.

[0085] like Figure 2 and Figure 3 As shown, at least one battery cell 30 has a state of charge characterized at least by a cell voltage. The at least one battery cell 30 further includes at least one electrode made of at least one active material, the at least one active material having a first voltage range characterized by a first voltage range Pl1 and a second voltage range characterized by a second voltage range Pl2. Figure 2 A characteristic curve in which such an active material associates specific capacitance with voltage is particularly shown. The active material constituting the electrode of the battery cell 30 can particularly have an olivine-type structure. For example, an olivine-like structure can correspond to the chemical formula LiFe z Y 1-z PO4, where 0 < z < 1, and where Y is a chemical element selected from the group including manganese, nickel, and cobalt. Advantageously, the value of z can be changed by varying the molar fraction of iron atoms or element Y atoms. In this way, the length of the first voltage plate and / or the second voltage plate can be changed. According to a non-limiting embodiment, the first voltage range Pl1 is included between 3.2 V and 3.6 V relative to a reference potential constituted by the electrochemical couple Li + / Li, more particularly included between 3.3 V and 3.5 V relative to a reference potential constituted by the electrochemical couple Li + / Li. Furthermore, according to this embodiment, the second voltage range Pl2 is included between 3.7 V and 4.3 V relative to a reference potential constituted by the electrochemical couple Li + / Li, more particularly included between 3.8 V and 4.1 V relative to a reference potential constituted by the electrochemical couple Li + / Li.

[0086] The at least one battery cell 30 is further capable of operating in a first operating mode Mod1 in which the battery cell 30 discharges, or a second operating mode Mod2 in which the battery cell 30 does not discharge. The module management system 11 is configured to determine, based on the cell voltage of the at least one battery cell 30, whether to selectively place the battery cell 30 in the operating mode selected from the first and second operating modes Mod1 and Mod2. That is, the module management system 11 uses the cell voltage of the at least one battery cell 30 to determine whether to place the battery cell 30 in the first operating mode Mod1 and / or whether to place the battery cell 30 in the second operating mode Mod2. Therefore, it can be readily understood that the cell voltage of the battery cell serves as a decision criterion for the module management system 11 to selectively place the battery cell 30 in one of the first and second operating modes Mod1 and Mod2. In particular, when the structure of the active material is an olivine-type structure, the active material may have a first voltage disc corresponding to the electrochemical potential of an iron atomic site and a second voltage disc corresponding to the electrochemical potential of a Y (e.g., manganese) atomic site. In this case, when the cell voltage of the battery cell 30 corresponds to a voltage within the first voltage range P11, the battery module 10 can decide to place the battery cell 30 in the first operating mode Mod1 to respond to a demand for high electric power, which is particularly suitable for structures including iron atoms. Alternatively, when the cell voltage of the battery cell 30 corresponds to a voltage within the second voltage range P12, the battery module 10 can decide to place the battery cell 30 in the first operating mode Mod1 to respond to a demand for electric energy for a sustained period of time, which is particularly suitable for structures including manganese atoms. Therefore, the module management system 11 is advantageously capable of selectively placing the battery cell 30 in the first operating mode Mod1 or the second operating mode Mod2 depending on the type of energy demand.

[0087] Figure 3 An embodiment is shown in which the battery module 10 includes a plurality of battery cells 30, wherein each battery cell 30 has a single cell voltage that is different from the cell voltages of the other battery cells 30. In particular, Figure 3A battery module 10 is shown, including nine battery cells 30 each having a single cell voltage. The first group of battery cells 30a clearly has a cell voltage corresponding to a voltage strictly below the first voltage range P11. The second group of battery cells 30b has a cell voltage corresponding to a voltage between the first voltage range P11 and the second voltage range P12. The third group of battery cells 30c has a cell voltage corresponding to a voltage strictly above the second voltage range P12. As previously mentioned, advantageously, if the demand for power from the external system is high, the module management system 11 can decide to place the second group of battery cells 30b in the first operating mode Mod1 to release more electrons within a predetermined time. On the other hand, if the demand for power from the external system is low, the module management system 11 can decide to place the third group of battery cells 30c in the first operating mode Mod1 to prolong the electron release over time. Thus, the electrochemical sites of the active materials of the electrodes of the battery cells 30 are selectively biased to respond to the precise demand for electrical energy. Consequently, the biasing of the battery cells 30 is tailored to their operation, which improves battery efficiency while also increasing the service life of the battery cells 30.

[0088] As described above, the module management system 11 is configured to determine whether to selectively place each of the plurality of battery cells 30 in an operating mode selected from the first and second operating modes Mod1 and Mod2 based on the individual battery cell voltages of the battery cells 30. The module management system 11 can also be configured to measure the cell voltages of the battery cells 30. According to one non-limiting variation, the module management system 11 is configured to measure the state of health (SoH) levels of the battery cells 30. In this case, the module management system 11 can be configured to determine whether to selectively place the battery cells 30 in an operating mode selected from the first and second operating modes Mod1 and Mod2 based on the SoH levels of the battery cells 30. Therefore, it can be well understood that the SoH levels are the decision criteria for placing the battery cells 30 in one of the first and second operating modes Mod1 and Mod2. Said state of health level of the battery cell 30 can in particular be determined by measuring one or more parameters included in the group consisting of the temperature of the battery cell 30, the voltage measured across the battery cell 30, the number of charge / discharge cycles performed by the battery cell 30, and the internal resistance of the battery cell 30. Finally, the module management system 11 can be configured to decide, based on a strategy algorithm recorded in the memory 12 of the module management system 11, to selectively place each battery cell 30 in an operating mode selected from the first and second operating modes Mod1, Mod2. hereinafter referred to Figure 6 An example of a policy algorithm is described.

[0089] According to a specific embodiment, the battery management system 3 can be configured to control each module management system 11. Therefore, it can be clearly understood that the battery management system 3 can be configured to transmit instructions intended for the module management system 11 to selectively place the battery cells 30 in at least one of the first and second operating modes Mod1, Mod2.

[0090] The arrangement described above makes it possible to propose a battery module 10 in which each cell 30 can be discharged according to its state of charge. Advantageously, the presence of an active material having two different voltage levels makes it possible to bias the cells 30 differently depending on the voltage level in which the active material is placed during the selection of the operating mode.

[0091] Reference Figures 4 to 6 The present invention also relates to a method for managing an energy storage unit 1 comprising a plurality of battery modules 10, the number of which is greater than or equal to two. Each battery module 10 comprises a module management system 11 and at least one battery cell 30. The management method may be implemented by the module management system 11 and first comprises: Step E1, receiving a request for power from an external system. For example, the external system may be an external motorized system such as the engine of an electric vehicle.

[0092] According to a non-limiting variant, the battery modules 10 of the plurality of battery modules 10, the number of which is greater than or equal to 2, are divided into a first group of battery modules Gr1 and a second group of battery modules Gr2, each group of battery modules Gr1, Gr2 including at least one of the plurality of battery modules 10. The energy storage unit 1 may further include a battery management system 3 configured to control each module management system 11. In this case, the management method may include: a step E2 of selecting a group of battery modules Gr1, Gr2 from the first and second groups of battery modules Gr1, Gr2, wherein only one of the first group of battery modules Gr1 or the second group of battery modules Gr2 implements the biasing step E6 described below. According to one embodiment, therefore, the management method may be implemented by the battery management system 3. Advantageously, each module management system 11 may be configured to: measure the state of health SoH level of the battery modules 10 included in the energy storage unit 1. In this case, the management method may include:

[0093] - step E11 , determining the state of health SoH level of at least one battery module 10 of the first group of battery modules Gr1 , this step E11 being performed on each battery module 10 of the first group of battery modules Gr1 by each module management system 11 ;

[0094] - step E12, determining the state of health SoH level of at least one battery module 10 of the second group of battery modules Gr2, this step E12 being implemented on each battery module 10 of the second group of battery modules Gr2 by each module management system 11;

[0095] - Step E13 , transmitting the state of health determined by the module management system 11 to the battery management system 3 .

[0096] According to one embodiment, steps E11 and E12 of determining the state of health SoH level of at least one battery module 10 of the first group of battery modules Gr1 and / or the second group of battery modules Gr2 include: measuring the temperature of the at least one battery module 10 of the first group of battery modules Gr1 and / or the second group of battery modules Gr2.

[0097] According to one embodiment, steps E11 and E12 of determining the state of health SoH level of at least one battery module 10 of the first group of battery modules Gr1 and / or the second group of battery modules Gr2 include: measuring the cell voltage of each battery cell 30 included in the at least one battery module 10 of the first group of battery modules Gr1 and / or the second group of battery modules Gr2.

[0098] According to one embodiment, steps E11 and E12 of determining the state of health SoH level of at least one battery module 10 of the first battery module Gr1 and / or the second battery module Gr2 include determining an average state of health SoH level of each battery cell 30 constituting the battery module 10 .

[0099] according to Figure 5 In the non-limiting variant shown, the management method may comprise the following steps implemented by the battery management system 3:

[0100] - Step E14 , receiving the health status of the first group of battery modules Gr1 ;

[0101] - Step E15 , receiving the health status level of the second group of battery modules Gr2 .

[0102] In this case, the step E2 of selecting a group of modules may be performed according to the health status of the first and second groups of battery modules Gr1 , Gr2 .

[0103] As described above, each battery module 10 includes at least one battery cell 30. The at least one battery cell 30 has a state of charge characterized at least by the cell voltage. The at least one battery cell 30 further includes at least one electrode made of at least one active material, the at least one active material having a first voltage plate and a second voltage plate, the first voltage plate being characterized by a first voltage range Pl1 in the characteristic curve of the specific capacitance of this active material as a function of voltage, the second voltage plate being characterized by a second voltage range Pl2 in the characteristic curve. For example, the active material of the electrode constituting the battery cell 30 has an olivine structure. The olivine structure may particularly correspond to the chemical formula LiFe z Y 1- z PO4, where 0 < z < 1, and where Y is a chemical element selected from the group including manganese, nickel, and cobalt. In this case, the first voltage range Pl1 may be included between 3.2 V and 3.6 V relative to the reference potential constituted by the electrochemical couple Li + / Li, more specifically, included between 3.3 V and 3.5 V relative to the reference potential constituted by the electrochemical couple Li + / Li. Furthermore, the second voltage range Pl2 may be included between 3.7 V and 4.3 V relative to the reference potential constituted by the electrochemical couple Li + / Li, more specifically, included between 3.8 V and 4.1 V relative to the reference potential constituted by the electrochemical couple Li + / Li.

[0104] Generally, the management method may be implemented for each battery cell 30 in the at least one battery cell 30. In other words, if the battery modules 10 of a plurality of battery modules 10 include a plurality of battery cells 30, the management method may be implemented for each battery cell 30 of the plurality of battery cells 30.

[0105] The management method further includes: step E3 of determining, for at least one battery cell 30 in the at least one battery cell 30, the cell voltage of this battery cell 30. The module management system 11 may be configured, for example, to measure the cell voltage of the battery cell 30. In this case, step E3 of determining the cell voltage may include measuring the cell voltage of the battery cell 30. For example, the measurement of the cell voltage of the battery cell 30 may be performed by measuring the voltage across the battery cell 30.

[0106] Then, the management method may include: step E4 of measuring the state of health SoH level of at least one battery cell 30. The module management system 11 may be particularly configured to measure the state of health SoH level of the at least one battery cell 30 during step E4 of measuring the state of health SoH level.

[0107] The management method may further include: step E5, comparing the power demand with a predetermined high threshold power, and comparing the power demand with a predetermined low threshold power. For example, when the battery cells 30 are fully charged, the high threshold power may correspond to the power required to fully discharge all battery cells 30 within one hour. The low threshold power may be equal to 0W.

[0108] Then, a step E6 of biasing the at least one battery cell 30 is performed. During this biasing step E6, the at least one battery cell 30 is selectively placed in a first operating mode Mod1 or a second operating mode Mod2, depending on the power demand and the cell voltage of the battery cell 30. In the first operating mode Mod1, the battery cell 30 is discharged, and in the second operating mode Mod2, the battery cell 30 is not discharged. The biasing step E6 can also be performed based on the state of health (SoH) level of the battery cell 30. Therefore, it is well understood that the SoH level and the cell voltage are the decision criteria for placing the battery cell 30 in one of the first and second operating modes Mod1 and Mod2.

[0109] In a non-limiting variant in which the comparison step E5 has been implemented, the offsetting step E6 may also comprise the following steps:

[0110] - placing the battery cell 30 in the first operating mode Mod1 when the cell voltage of the battery cell 30 corresponds to a voltage included in the first voltage range P11 and the demand for power is greater than or equal to the high threshold power;

[0111] - placing the battery cell 30 in the first operating mode Mod1 when the cell voltage of the battery cell 30 corresponds to a voltage included in the second voltage range P12 and the power demand is strictly included between the high threshold power and the low threshold power;

[0112] Otherwise, the battery cell 30 is placed in the second operating mode Mod2 .

[0113] According to one embodiment, the biasing step E6 may further include the following step: when the cell voltage of the battery cell 30 corresponds to a voltage that is neither included in the second voltage range Pl2 nor in the first voltage range Pl1, and the power demand is strictly greater than the low threshold power, placing the battery cell 30 in the first operating mode Mod1.

[0114] According to a non-limiting variation in which the battery module 10 includes a plurality of battery cells 30, wherein each battery cell 30 has a single cell voltage that is different from the cell voltages of the other battery cells 30, the biasing step E6 can be implemented for all or part of the battery cells 30 of the plurality of battery cells 30 depending on the power demand and the single cell voltage of each battery cell 30.

[0115] Alternatively or collectively, when the battery modules 10 of the plurality of battery modules 10 include a plurality of battery cells 30 greater than or equal to two, the biasing step E6 may further include the following steps:

[0116] - when the cell voltage of the battery cell 30 corresponds to a voltage included in the first voltage range P11, the power demand is strictly included between the high threshold power and the low threshold power, and none of the other battery cells 30 of the battery module 10 has a cell voltage corresponding to a voltage included in the second voltage range P12, placing the battery cell 30 in the first operation mode Mod1; - when the cell voltage of the battery cell 30 corresponds to a voltage included in the second voltage range P12,

[0117] When the power demand is greater than or equal to the high threshold power and none of the other battery cells 30 in the battery module 10 has a cell voltage corresponding to a voltage included in the first voltage range P11 , the battery cell 30 is placed in the first operation mode Mod1 .

[0118] According to another embodiment, when a given battery module 10 among a plurality of battery modules 10 includes a plurality of battery cells 30 greater than or equal to two, the biasing step E6 may further include the following steps: when the cell voltage of at least one battery cell 30 among the battery cells 30 of the given battery module 10 is included in the second voltage range Pl2 and the power demand is strictly greater than the low threshold power, all the battery cells 30 of the given battery module 10 are placed in the first operating mode Mod1.

[0119] Finally, the management method may include step E7 of transmitting discharge information. For example, step E7 may include transmitting discharge information to the user interface when the cell voltages of all battery cells 30 in the battery modules 10 of the plurality of battery modules 10 are below a minimum cell voltage. For example, the minimum cell voltage may correspond to a state of charge, that is, the amount of energy remaining in the battery, which may be less than 10%, or more specifically, less than 5%.

[0120] according to Figure 6In one embodiment shown, the management method can be implemented by a strategy algorithm recorded in the memory 2 of the battery management system 3 or in the memory 12 of the module management system 11. The algorithm can be implemented iteratively within the total number "n" of battery cells 30. Figure 6 As shown, for each battery cell 30 (denoted “i”), steps E3 , E4 , E5 and E6 may be iteratively performed in order to provide electrical energy to the external system according to the power demand received during step E1 .

[0121] The arrangement described previously makes it possible to propose a battery management method capable of placing the cells 30 in a state of discharge as a function of their cell voltage and of the power demand from the external system to be supplied with electrical energy by the energy storage unit 1. Thus, advantageously, given the presence of two voltage levels for the active material constituting the electrodes of the cells 30, the cells 30 can be selectively biased as a function of the voltage level in which they are placed at a given time.

Claims

1. A battery module (10) comprising a module management system (11) and at least one battery cell (30) having a state of charge characterized by at least one cell voltage, the at least one battery cell (30) comprising at least one electrode composed of at least one active material having a chemical formula corresponding to LiFe z Y 1-z An olivine-type structure of PO4, wherein 0 < z < 1, and wherein Y is a chemical element selected from the group consisting of manganese, nickel, and cobalt, the at least one active material having a first voltage plateau and a second voltage plateau, the first voltage plateau being characterized by a first voltage range (PI1) in a characteristic curve of the active material relating specific capacitance to voltage, the first voltage range corresponding to the electrochemical potential of an iron atom, the second voltage plateau being characterized by a second voltage range (PI2) in the characteristic curve, the second voltage range corresponding to the electrochemical potential of an atom Y, the at least one battery cell (30) being capable of: - a first operating mode (Mod1) in which the battery cell (30) is discharged, - a second operating mode (Mod2) in which the battery cells (30) are not discharged, The module management system (11) is configured to: place the battery cell (30) in the first operating mode (Mod1) according to whether the cell voltage of the at least one battery cell (30) corresponds to a voltage included in the first voltage range (Pl1) or corresponds to a voltage included in the second voltage range (Pl2), and in the case where the cell voltage of the battery cell (30) corresponds to a voltage included in the first voltage range (Pl1) and the power demand is greater than or equal to a high threshold power; place the battery cell (30) in the first operating mode (Mod1) according to whether the cell voltage of the battery cell (30) corresponds to a voltage included in the second voltage range (Pl2) and the power demand is strictly included between the high threshold power and the low threshold power; otherwise, place the battery cell (30) in the second operating mode (Mod2).

2. The battery module (10) according to claim 1, wherein: The first voltage range (Pl1) is relative to the electrochemical couple Li + / Li is comprised between 3.2 V and 3.6 V, and wherein said second voltage range (PI2) is relative to the reference potential of the electrochemical couple Li + The reference potential of the MgO / Li composition is comprised between 3.7 V and 4.3 V.

3. The battery module (10) according to claim 2, wherein: The first voltage range (Pl1) is relative to the electrochemical couple Li + The reference potential of the CMOS / Li composition is comprised between 3.3 V and 3.5 V.

4. The battery module (10) according to claim 2, wherein: The second voltage range (Pl2) is relative to the electrochemical couple Li + The reference potential of the MgO / Li composition is comprised between 3.8 V and 4.1 V.

5. The battery module (10) according to claim 1, wherein: The module management system (11) is configured to measure the cell voltage of the battery cell (30).

6. The battery module (10) according to claim 1, wherein: The module management system (11) is configured to measure the state of health (SoH) level of the battery cell (30), and the module management system (11) is further configured to decide to selectively place the battery cell (30) in an operating mode selected from the first operating mode and the second operating mode (Mod1, Mod2) based on the state of health (SoH) level of the battery cell (30).

7. The battery module (10) according to claim 1 comprises a plurality of battery cells (30), wherein each battery cell (30) has a single cell voltage that is different from the cell voltages of other battery cells (30), and the module management system (11) is configured to: determine, based on the single cell voltage of the battery cell (30), to selectively place each battery cell (30) of the plurality of battery cells (30) in an operating mode selected from the first operating mode and the second operating mode (Mod1, Mod2).

8. The battery module (10) according to claim 7, wherein: The module management system (11) is configured to decide, based on a strategy algorithm recorded in a memory (12) of the module management system (11), to selectively place each battery cell (30) in an operating mode selected from the first operating mode and the second operating mode (Mod1, Mod2).

9. An energy storage unit (1) comprising at least two battery modules (10) according to any one of claims 1 to 8, and a battery management system (3), wherein the battery management system (3) is configured to control each of the module management systems (11) of the at least two battery modules (10) according to a demand for power from an external system.

10. A method for managing an energy storage unit (1) according to claim 9, the management method comprising: - Step (E1), receiving a demand for power from an external system; - Step (E3), determining the cell voltage of at least one battery cell (30) of the at least one battery cell (30); - Step (E6), depending on whether the cell voltage of the at least one battery cell (30) corresponds to a voltage included in the first voltage range (Pl1) or corresponds to a voltage included in the second voltage range (Pl2), and depending on the power demand, selectively biasing the battery cell (30) in a first operating mode (Mod1) in which the battery cell (30) is discharged or in a second operating mode (Mod2) in which the battery cell (30) is not discharged.

11. The management method according to claim 10, wherein: The first voltage range (Pl1) is relative to the electrochemical couple Li + / Li is comprised between 3.2 V and 3.6 V, and wherein said second voltage range (PI2) is relative to the reference potential of the electrochemical couple Li + The reference potential of the MgO / Li composition is comprised between 3.7 V and 4.3 V.

12. The management method according to claim 11, wherein: The first voltage range (Pl1) is relative to the electrochemical couple Li + The reference potential of the CMOS / Li composition is comprised between 3.3 V and 3.5 V.

13. The management method according to claim 11, wherein: The second voltage range (Pl2) is relative to the electrochemical couple Li + The reference potential of the MgO / Li composition is comprised between 3.8 V and 4.1 V.

14. The management method according to claim 10, further comprising: Step (E5), comparing the demand for power with a predetermined high threshold power, and comparing the demand for power with a predetermined low threshold power, the biasing step (E6) further comprising the following steps: - placing the battery cell (30) in the first operating mode (Mod1) when the cell voltage of the battery cell (30) corresponds to a voltage included in the first voltage range (Pl1) and the power demand is greater than or equal to a high threshold power; - placing the battery cell (30) in the first operating mode (Mod1) when the cell voltage of the battery cell (30) corresponds to a voltage included in the second voltage range (Pl2) and the power demand is strictly included between a high threshold power and a low threshold power; - Otherwise, placing the battery cell (30) in the second operating mode (Mod2).

15. The management method according to claim 10, further comprising: Step (E4) measures the state of health (SoH) level of the at least one battery cell (30), and the biasing step (E6) is performed according to the state of health (SoH) level of the battery cell (30).

16. The management method according to claim 10, wherein: One battery module (10) among the plurality of battery modules (10) includes a plurality of battery cells (30), wherein each battery cell (30) has a single cell voltage that is different from the cell voltages of other battery cells (30), and the biasing step (E6) is implemented for all or part of the battery cells (30) of the plurality of battery cells (30) according to power requirements and the single cell voltage of each battery cell (30).

17. The management method according to claim 10, wherein: The battery modules (10) of the plurality of battery modules (10) whose number is greater than or equal to 2 are divided into a first group of battery modules (Gr1) and a second group of battery modules (Gr2), each group of battery modules (Gr1, Gr2) includes at least one of the plurality of battery modules (10), the energy storage unit (1) further includes: a battery management system (3) configured to control each module management system (11), the management method comprising: a step (E2), selecting a group of battery modules (Gr1, Gr2) from the first group of battery modules and the second group of battery modules (Gr1, Gr2), wherein only one of the first group of battery modules (Gr1) or the second group of battery modules (Gr2) implements the biasing step (E6).

18. The management method according to claim 17, further comprising the following steps implemented by the battery management system (3): - Step ( E14 ), receiving the health status level of the first group of battery modules ( Gr1 ); - Step ( E15 ), receiving the health status level of the second group of battery modules ( Gr2 ); A step (E2) of selecting a group of modules is performed according to the health status of the first group of battery modules and the second group of battery modules (Gr1, Gr2).

19. The management method according to claim 17 or 18, wherein: Each module management system (11) is configured to measure the state of health (SoH) level of the battery module (10) included in the energy storage unit (1), and the management method includes: - a step (E11) of determining a state of health (SoH) level of at least one battery module (10) of the first group of battery modules (Gr1), said step (E11) being performed on each battery module (10) of the first group of battery modules (Gr1) by each module management system (11) of the first group of battery modules (Gr1); - a step (E12) of determining a state of health (SoH) level of at least one battery module (10) of the second group of battery modules (Gr2), said step (E12) being performed on each battery module (10) of the second group of battery modules (Gr2) by each module management system (11) of the second group of battery modules (Gr2); - Step (E13) of transmitting the state of health determined by the module management system (11) to the battery management system (3).

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