GB2623086A

GB2623086A - A method for predicting a status of a battery cell with a metal anode of an electrical energy storage device of a vehicle by a management device as well as a

Info

Publication number: GB2623086A
Application number: GB2214559.3A
Authority: GB
Inventors: Glossmann Tobias
Original assignee: Mercedes Benz Group AG
Current assignee: Mercedes Benz Group AG
Priority date: 2022-10-04
Filing date: 2022-10-04
Publication date: 2024-04-10
Also published as: WO2024074245A2; GB202214559D0

Abstract

Electrical energy storage device 10 of a motor vehicle has battery cell 12 and management device 14. Detecting device 32 of the management device detects a parameter of the battery cell. Electronic computing device 34 of the management device determines a mathematical model 22 for a metal anode of the battery cell, and predicts battery cell status based on the parameter and the model. A current recommendation (e.g. current range), temperature recommendation (e.g. temperature range), or criticality level may be determined, and an operating limit of the battery cell, storage device or motor vehicle may be adjusted. The operating limit may be a charging or discharging profile. The status may be a condition of the metal anode, such as stack pressure, displacement or plating condition. The metal anode may be a lithium-metal anode.

Description

A method for predicting a status of a battery cell with a metal anode of an electrical energy storage device of a vehicle by a management device as well as a corresponding management device

FIELD OF THE INVENTION

[0001] The present invention relates to the field of automobiles. More specifically, the present invention relates to a method for predicting a status of a battery cell with a metal anode of an electrical energy storage device of a motor vehicle by a management device of the electrical energy storage device as well as to a corresponding management device.

BACKGROUND INFORMATION

[0002] So-called secondary battery cells that is rechargeable battery cells, which comprise lithium metal anodes are charged by electrochemical deposition of lithium ions that react with an electron as opposed to intercalation in graphite or reaction with silicon-containing anode materials and lithium-ion batteries. Metals such as lithium, sodium, aluminum, or magnesium usually consists of single crystals that are held together by cohesive forces. If a metal comprises impurities, they may agglomerate at the grain boundaries, depending on the temperature treatment or deposition mode. Temperature changes of the battery cell and charge rates may have an impact on the microstructure of the plated metal. Thus, the mechanical properties of the anode depend on operating limits of the battery cell, electrical energy storage device and/or the motor vehicle such as the charge and discharge profiles.

[0003] Many lithium-metal anode designs may rely on the temperature, grain size, and strain-rate of lithium. The ductility of lithium may depend on the strain rate and grain size, and the plating rate of metal may change the structure of the anode. Often stack pressure is applied to ensure dense and homogenous metal plating. Non-homogenous and non-dense metal leads to problems, for example, a lower cycle life due to a detached lithium, lower energy density due to cell expansion, and compromised safety due to increased surface area.

SUMMARY OF THE INVENTION

[0004] It is an object of the present invention to provide a method as well as a management device by which a more reliable functionality of a battery cell may be realized. By managing the changes in the metal anode such as a lithium-metal anode, the operation and performance of a battery cell of an electrical energy storage device may be monitored, predicted, and controlled. Additionally, the operability and predictability of battery cells with plated metal electrodes may be optimized and may be monitored to provide data for vehicle systems such as the charging and discharging systems. The battery management system may then manage the metal anode with the present invention by modeling the metal anode with data such as the charge rate and temperature.

[0005] This object is solved by a method as well as a management device according to the independent claims. Advantageous embodiments are presented in the dependent claims.

[0006] One aspect of the present invention relates to a method for predicting a status of a battery cell of an electrical energy storage device of a motor vehicle by a management device of the electrical energy storage device. At least one parameter of the battery cell may be detected by a detecting device of the management device. A mathematical model for a metal anode of the battery cell may be determined by an electronic computing device of the management device. Depending on the detected parameter and the mathematical model, the status of the battery cell may be predicted by the electronic computing device. In some embodiments, a current and/or a voltage and/or a temperature as the parameter are detected by the detecting device.

[0007] Therefore, an additional functionality may be implemented in the electrical energy storage device. In particular, the battery control system may monitor and control the battery cell in a closed-loop system based on the status of the battery cell and the metal anode. Monitoring and modeling parameters to determine operating limits of the metal anode, the battery cell, the electrical energy storage system, and/or the motor vehicle may provide data such as the status of charge, charge rate, temperature, and/or other data.

For example, the charging and discharging temperatures of a metal anode may be monitored and modeled to produce a digital twin or digital representation of the metal anode for predicting the status of the battery cell. During the process to predict the current status of the battery cell which may include the metal anode, the present invention may provide data about the microstructure in every plated metal layer. Lithium metal anode, in particular, may require monitoring, modeling, and adjusting of operating conditions and/or limits in addition to the state of charge, and single cell control. The model for the anode, may be utilized to optimize charging for more desirable metal properties, recover capacity, prevent cell failure, extend cycle life, and/or make safety performance manageable. In some embodiments, the battery management system may include the functionality to model the digital representation of the metal anode such as a lithium anode. In another embodiment, the battery management system may detect the parameter of the battery cell, the electrical energy storage device, and/or the motor vehicle.

[0008] The predicted status may include a metal condition of the anode of the battery cell. In certain embodiments, the metal condition may include a stack pressure, a displacement, and/or a plating condition. For example, the metal condition may include the stack pressure and the stripping condition of the metal anode in the battery cell.

[0009] The method for predicting a status of a battery cell with a metal anode of an electrical energy storage device of a motor vehicle may further include steps to determine a recommendation. In some embodiments, the recommendation may include a current recommendation and/or a temperature recommendation by the electronic computing device based on the parameter and the mathematical model. In another embodiment, the current recommendation may include a current range, and the temperature recommendation may include a temperature range.

[0010] Additionally, the method may include steps for determining a current limit by the electronic computing device based on the parameter and the mathematical model and determining a level of criticality for at least one of the recommendation or the current limit by the electronic computing device based on the parameter and the mathematical model. In another embodiment, at least one of a temperature limit and/or recommendation or a current limit and/or recommendation may correspond to the charging profile and/or the discharging profile and may be used by the electronic computing device to maximize the operation of a battery cell with a metal anode.

[0011] Furthermore, the method may include steps for adjusting an operating limit of at least one of the battery cell, the electrical energy storage device, or the motor vehicle by the electronic computing device based on at least of one of the status of the battery cell, the recommendation, the current limit, or the level of criticality. In certain embodiments, the operation condition may include a charging and/or discharging profile, which may be adjusted by the electronic computing device. For example, the charging management system and/or the battery management system may adjust the charging profile for the electrical energy storage device.

[0012] In a different embodiment, the mathematical model may be trained by experimental data. In another embodiment, the mathematical model may be trained by a predicted set(s) of anode model data from the mathematical model, determined recommendation(s), determined current limit(s), predicted battery cell status(es), determined level(s) of criticality, and/or the adjusted operating limit(s).

[0013] In particular, the method may be a computer-implemented method. Therefore, another aspect of the present invention relates to a computer program product including program code means for performing the method. A still further aspect of the present invention relates to a computer-readable storage medium including the computer program code. For example, the method may be implemented in a non-transitory computer-readable medium having instructions which, when executed by the electronic computing device, may causes a processing circuit to perform the method according to the preceding aspect.

[0014] Another aspect of the present invention relates to a management device of an electrical energy storage device for predicting a status of a battery cell with a metal anode of an electrical energy storage device of a motor vehicle, the management device including at least one detecting device and one electronic computing device, wherein the management device may be configured for performing a method according to the preceding aspect. In particular, the method is performed by the management device.

[0015] Furthermore, the present invention relates to an electrical energy storage device including a management device according to the preceding aspect. Furthermore, the present invention relates to a motor vehicle including an electrical energy storage device according to the preceding aspect. In particular, the motor vehicle may be configured at least in part as an electrically operated motor vehicle.

[0016] The detecting device may include sensors and other detection devices for temperature, current, voltage, pressure, displacement, and/or other parameters related to the battery cell, the electrical energy storage device, and/or the motor vehicle. For example, the detection device may include processors, circuits, in particular, integrated circuits, and further electrical means, for detecting the parameter(s). The management device may include the detecting device and/or the electronic computing device. Furthermore, the management device may also include processors, circuits, in particular, integrated circuits, and further electrical means, for performing the method. For example, the management device may include a battery management system, a charging management system, and/or comparable system in the motor vehicle.

[0017] The electronic computing device may include the management device and/or the detecting device. For example, the electronic computing device may include a component of the battery management system, the charging management system, and/or comparable system in the motor vehicle. Additionally, the electronic computing device may include processors, circuits, in particular, integrated circuits, and further electrical means, for performing the method.

[0018] Advantageous embodiments of the method are to be regarded as advantageous embodiments of the management device, the electrical energy storage device, as well as the motor vehicle. Therefore, the management device, the electrical energy storage device, as well as the motor vehicle includes means for performing the method.

[0019] Further advantages, features, and details of the present invention derive from the following description of preferred embodiments as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and/or shown in the figures alone can be employed not only in the respectively indicated combination but also in any other combination or taken alone without leaving the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The novel features and characteristic of the disclosure are set forth in the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and together with the description, serve to explain the disclosed principles. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described below, by way of example only, and with reference to the accompanying figures.

[0021] The drawings show in: [0022] Fig. 1 a flow chart diagram according to an embodiment of the method; [0023] Fig. 2 a schematic block diagram according to an embodiment of a management device; [0024] Fig. 3 a schematic block diagram according to an embodiment of an electrical energy storage device; and [0025] Fig. 4 another schematic block diagram according to an embodiment of the method.

[0026] In the figures, the same elements or elements having the same function are indicated by the same reference signs.

DETAILED DESCRIPTION

[0027] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0028] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0029] The terms "comprises'', "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion so that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus preceded by "comprises" or "comprise" does not or do not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

[0030] In the following detailed description of the embodiment of the disclosure, reference is made to the accompanying drawings that form part hereof, and in which is shown by way of illustration a specific embodiment in which the disclosure may be practiced. This embodiment is described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0031] Fig. 1 shows a schematic flowchart according to an embodiment of the method. A method for predicting a status of a battery cell 12 (Figs. 3 and 4) of an electrical energy storage device 10 (Fig. 3) of a motor vehicle by a management device 14 (Figs. 2-4) of the electrical energy storage device 10 is provided. In a first step Si. detecting at least one parameter 24, 26, 28, 30 (Fig. 4) of the battery cell 12 by a detecting device 32 (Figs. 2 and 3) of the management device 14 is provided. In a second step S2, a mathematical model 22 (Figs. 3 and 4) is determined for a metal anode of the battery cell 12 by an electronic computing device 34 (Figs. 2 and 4) of the management device 14. In a third step S3, predicting the status of the battery cell 12 by the electronic computing device 34 is performed based on the parameter 24, 26, 28, 30 and the mathematical model 22.

[0032] Battery cells 12 with metal anodes may experience performance, reliability, and safety issues, and lithium-metal anodes may be electrochemically and mechanically unstable resulting in operational issues. Therefore, an additional functionality may be implemented in the electrical energy storage device 10 with metal anodes such as lithium-metal battery cells. The present invention may enable predictable performance of battery cells 12 with metal anodes by detecting parameters 24, 26, 28, 30 related to the metal anode, determining a mathematical model 22 for the metal anode, predicting the status of the battery cell 12 and/or the metal anode, and/or adjusting an operation condition for the system. For example, the management device 14 with the electronic computing device 34 may determine a current limit for the battery cell 12 and may apply the current limit to the electrical energy storage device 10 based on the mathematical model 22 of the lithium-metal anode.

S

[0033] In particular, the battery control system may monitor and control the battery cell 12 in a closed-loop system based on the status of the battery cell 12 and the metal anode and may refine the mathematical model 22 of the metal anode for improved status predictions. The model for the metal anode may be utilized to optimize charging for more desirable metal properties, recover capacity, prevent cell failure, extend cycle life, and/or make safety performance manageable. In some embodiments, the battery management system may include the functionality to model the digital representation of the anode such as the lithium-metal anode.

[0034] The incorporation of the mathematical model 22 of the metal anode may improve the functionality of the management device 14 for the battery cells 12, the electrical energy storage device 10, and/or the motor vehicle. If part of the metal anode is already deposited and the battery management system detects that the ductility is low, the battery management system may implement an operating condition, a current recommendation and/or a current limit that may modify the properties of the metal anode in a beneficial way during the next charging process. , For example, by increasing the temperature and applying a certain charge profile to modify the strain-rate, the metal deformation for the metal anode may be alleviated. With less ductile lithium plated, the system may reduce the mechanical stress caused by the charging rate which is beneficial to improved operability, reliability, and/or safety. Furthermore, charge currents that may lead to a strong dendrite during vehicle deceleration can be limited advantageously in such a way that recuperative braking can be utilized to the maximize energy efficiency.

[0035] Fig. 2 shows a schematic block diagram according to an embodiment of a management device 14. The electrical energy storage device 10 may be connected to the management device 14, which may also be called a battery management system. The management device 14 may include at least the one detecting device 32 and the one electronic computing device 34.

[0036] Fig. 3 shows a schematic block diagram according to an embodiment of the electrical energy storage device 10 for a motor vehicle (not shown). The motor vehicle may be configured at least in part as an electrically operated motor vehicle or a fully electrically operated electrical motor vehicle. The electrical energy storage device 10 may be configured as a lithium-metal battery system. Therefore, the electrical energy storage device 10 may include at least one battery cell 12, in particular a plurality of battery cells 12. The electrical energy storage device 10 may include the management device 14, which may also be called a battery management system. Therefore, the management device 14 may be configured for the managing operating limits 16, adjusting operating limits 16, managing a state of charge 18, and providing a single cell control 20 as well as the mathematical model 22. In some embodiments, there may be an initial set of operating limits 16, which may be used to develop a subsequent set(s) of operating limits.

[0037] In particular, in Fig. 3 an electrical energy storage device 10 for a motor vehicle is shown, wherein at least one parameter 24, 26, 28, 30 (Fig. 4) of the battery cell 12 may be detected by a detecting device 32 of the management device 14. The mathematical model 22 may be provided for a metal anode of the battery cell 12 by an electronic computing device 34 (Fig. 2) of the management device 14. Depending on the detected parameter 24, 26, 28, 30 and the mathematical model 22, the status of the battery cell 12 may be predicted by the electronic computing device 34.

[0038] Fig. 4 shows another schematic block diagram according to an embodiment of the present invention. Fig. 4 shows, that a current 24, a voltage 26, a temperature 28, and/or other measurement signals 30 may be inputted into the management device 14 as the parameter 24, 26, 28, 30. Other signals 30 may be, for example, a stack pressure, displacement, or depending on the battery pack additional anode information such as design details that may be extractable to improve the mathematical model 22.

[0039] The mathematical model 22 may produce an actual physical properties of the metal anode, a desired physical properties of the metal anode, a strategic recommendation to keep the electrode in a specific range, an absolute current limit, a level of energy, and/or a level of urgency/criticality, in particular, how close the electrode is to leaving the desired range of physical properties. In some embodiments, the electronic computing device 34 of the management device 14 which may be a battery management system may also calculate the actual physical properties of the metal anode, the desired physical properties of the metal anode, the strategic recommendation to keep the electrode in a specific range, the absolute current limit, the level of energy, and/or the level of urgency/criticality.

[0040] The management device 14 may include the mathematical model 22. The mathematical model 22 may also include an annealing block 44 as well as a block for identification of plating and/or stripping, which bears the reference sign 46. The annealing block 44 may receive temperature data in order to monitor the temperature components that may impact the physical properties of the anode in the battery cell 12. The mathematical model 22 also may monitor the temperature for the metal that is currently plated and/or for already plated metal because the physical properties of the metal anode might change because of annealing or other effects that may occur. According to an embodiment, management of high currents may also be beneficial for the longevity of a metal electrode, which may be related to temperature effects.

[0041] The plating and/or stripping block 46 may also receive temperature, voltage, and/or current data from the detecting device 32. The plating and/or stripping block 46 may provide information on the added and stripped metal of the anode to the mathematical model 22. For example, the different layers of the battery cell 12 as shown in Fig. 2 may symbolize different plating conditions. Each layer of the metal anode may represent a plating condition such as electrochemically plated or reverse reaction. For the electrochemically plated condition, the state of charge may be increased as metal is added. When the metal is reduced or stripped in the battery cell 12, the reverse reaction condition may be present.

[0042] The data from the annealing block 44 and/or the plating and/or stripping block 46 may be used by the mathematical model 22 to develop the model data of the anode of the battery cell 12. In some embodiments, the mathematical model 22 may transmit data to the annealing block 44 and/or the plating and/or stripping block 46 to improve the physical property and/or plating condition data used to develop the model data of the anode. For example, the mathematical model 22 may operate as an integration model to optimize the data inputs to produce model data of the metal anode as properties and/or conditions vary.

[0043] The management device 14 with the mathematical model 22 may determine the structure of the each layer of the anode dynamically or statically. In certain embodiments, the mathematical model 22 may be trained and/or calibrated with empirical data, experimental data, and/or other data. The mathematical mode 22, for example, may monitor current data from historical data, testing data, and operating conditions because current levels may impact the operability of a metal anode in the battery cell 12. The deposition data may be used by the mathematical model 22 to determine the model data of the anode and predict the status of the battery cell 12. In some embodiments, the electronic computing device 34 may determine the model data of the anode and predict the status of the battery cell 12.

[0044] Current recommendations 36, temperature recommendations 38, current limits 40, as well as a level of criticalness for the recommendation 42 may be provided by the electronic computing device 34 as additional outputs. For example, the temperature recommendation 38 may include a preferred operation temperature value and/or range of values. The temperature recommendation 38 may include a preferred operating zone inside the range of temperature values, and in some embodiments, the temperature recommendation 38 may include the recommended range and the preferred operating temperature for the metal anode battery cell 12.

[0045] The management device 14 may also monitor a charging history, which may also be referred to as a plating history, and a discharging history, which may also be referred to as a stripping history. The mathematical model 22 of the battery cell 12 may show the layers of the metal anode, dynamically or statically, and may show how each layer of the metal anode was deposited. One or more functions of the electronic computing device 34 of the management device 14 may monitor and determine local and total mechanical properties from the deposition history. For example, high current levels may be detected and the management device 14 may determine a current recommendation 36 and/or current limit 40 that may take advantage of the current data. For example, the current recommendation 36 and the current limit 40 may include a charge current and a discharge current value and/or range of values. The current recommendation 36 may include a preferred operating value and/or zone inside the range of charge and/or discharge current values.

[0046] The model data as well as the predicted status of the battery cell 12 may also include physical properties and/or conditions of the metal anode and/or the battery cell 12 caused by current, voltage, temperature, and/or other inputs. The physical properties and/or conditions may be determined using statistical and/or analytical methods by the electronic computing device 34. In certain embodiments, the mathematical model 22 may also implement the statistical and/or analytical calculations. The electronic computing device 34 or the mathematical model 22 may include an algorithm that may calculate limits but also recommendations on current and temperature so that the values can be communicated to the charge controls and vehicle controls. The algorithm may also be calibrated with experimental data. The experimental data may be derived from experimentation such as micro-indention that may produce data about the properties and/or conditions of plated or electrochemically deposited metal.

List of Reference Signs electrical energy storage device 12 battery cell 14 management device 16 operating limits 18 state of charge single cell control 22 mathematical model 24 current 26 voltage 28 temperature other signals 32 detecting device 34 electronic computing device 36 current recommendations 38 temperature recommendation current limits 42 level of criticalness 44 annealing 46 plating and/or stripping block 51 -53 steps of the method

Claims

CLAIMS1. A method for predicting a status of a battery cell (12) of an electrical energy storage device (10) of a motor vehicle by a management device (14) of the electrical energy storage device (10), the method comprising the steps of: - detecting at least one parameter (24, 26, 28, 30) of the battery cell (12) by a detecting device (32) of the management device (14); - determining a mathematical model (22) for a metal anode of the battery cell (12) by an electronic computing device (34) of the management device (14); and - predicting the status of the battery cell (12) by the electronic computing device (34) based on the parameter (24, 26, 28, 30) and the mathematical model (22).
2. The method according to claim 1, further comprising the steps of: - determining a recommendation (36, 38), characterized in that, the recommendation (36, 38) is at least one of a current recommendation (36) or a temperature recommendation (38) by the electronic computing device (34) based on the parameter (24, 26, 28, 30) and the mathematical model (22); -determining a current limit (40) by the electronic computing device (34) based on the parameter (24, 26, 28, 30) and the mathematical model (22); and -determining a level of criticality (42) for at least one of the recommendation (36, 38) or the current limit (40) by the electronic computing device (34) based on the parameter (24, 26, 28, 30) and the mathematical model (22).
3. The method according to any one of claims 1 or 2, further comprising the steps of adjusting an operating limit (16) of at least one of the battery cell (12), the electrical energy storage device (10), or the motor vehicle by the electronic computing device (34) based on at least one of the status of the battery cell (12), the recommendation (36, 38), the current limit (40), or the level of criticality (42).
4. The method according to claim 3, characterized in that the operating limit (16) is at least one of a charging profile or a discharging profile.
5. The method according to any one of claims 1 to 4, characterized in that the status is a metal condition of the metal anode of the battery cell (12).
6. The method according to any one of the claims 1 to 5, characterized in that the metal condition is at least one of a stack pressure, a displacement, or a plating condition.
7. The method according to any one of claims 2 to 6, characterized in that the current recommendation (36) is a current range and the temperature recommendation (38) is a temperature range.
8. The method according to any one of claims 1 to 7, characterized in that the metal anode of the battery cell (12) is a lithium-metal anode.
9. A management device (14) of an electrical energy storage device (10) for predicting a status of a battery cell (12) of the electrical energy storage device (10) of a motor vehicle, the management device (14) comprising at least one detecting device (32) and one electronic computing device (34), wherein the management device (14) is configured for performing a method according to any one of claims 1 to 8.
10. A non-transitory computer-readable medium having instructions which, when executed by an electronic computing device (34), causes a processing circuit to perform a method according to any one of claims 1 to 8.