Information processing systems, information processing methods, and programs

Abstract

To efficiently obtain a degradation rate map for multiple secondary batteries by conducting degradation tests in parallel and based on the results, there is room for improvement in how test conditions are selected during the degradation tests. [Solution] According to one aspect of the present invention, an information processing system is provided, comprising at least one processor, the processor configured to execute a program such that the following steps are performed: an acquisition step, a identification step, an extraction step, a degradation rate calculation step, a generation step, a comparison step, and an output step.

Description

[Technical Field]

[0001] This invention relates to an information processing system, an information processing method, and a program. [Background technology]

[0002] Patent Document 1 discloses an information processing system, etc., that can obtain a degradation rate map while reducing testing costs compared to conventional testing methods.

[0003] This information processing system includes at least one processor capable of executing a program to perform the following steps: The acquisition step acquires the test conditions of a first degradation test performed on a secondary battery and the test results from the first degradation test. The test conditions include the test time required to perform the first degradation test. The test results include the amount of capacity degradation of the secondary battery. The rate calculation step calculates the capacity degradation rate of the secondary battery under the test conditions based on the amount of capacity degradation. The estimation step estimates the capacity degradation rate of the secondary battery under at least one untested condition representing test conditions that have not been acquired, based on the calculated capacity degradation rate. The map generation step generates a degradation rate map showing the correspondence between test conditions and capacity degradation rates, based on the calculated capacity degradation rate and the estimated capacity degradation rate. The priority calculation step calculates the priority of each untested condition for performing a second degradation test based on the generated degradation rate map. The candidate output step outputs candidates for a second degradation test, using at least one of the untested conditions as the test condition, in a manner that allows the user to select, based on the calculated priority.

[0004] Non-patent documents 1 and 2 are for reference only. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2024-113242 [Non-patent literature]

[0006] [Non-Patent Document 1] J. de Hoog et al., "Combined cycling and calendar capacity fade modeling of a Nickel-Manganese-Cobalt Oxide Cell with real-life profile validation", Applied Energy, 200, 47-61, (2017). [Non-Patent Document 2] M. Naumann et al., "Analysis and modeling of cycle aging of a commercial LiFePO4 / graphite cell", Journal of Power Source, vol. 451, pp. 227666, (2020). [Overview of the project] [Problems that the invention aims to solve]

[0007] By the way, in order to efficiently obtain a degradation rate map of a secondary battery by conducting degradation tests on multiple secondary batteries in parallel and based on the results, there is room for improvement in how the test conditions are selected during the degradation tests. [Means for solving the problem]

[0008] According to one aspect of the present invention, an information processing system comprising at least one processor, the processor configured to execute a program such that the following steps are performed: an acquisition step, which acquires battery information relating to the configuration of a target battery which is a battery to be tested in a degradation test, and information relating to the number of the target battery; an identification step, which identifies a reference degradation rate map based on the battery information and a degradation rate map relating to a reference battery different from the target battery, the degradation rate map showing the relationship between the test conditions of the battery and the capacity degradation rate of the battery under those test conditions, the reference degradation rate map being a degradation rate map used for comparison when estimating the initial degradation rate map of the target battery; and an extraction step, which extracts a number corresponding to the number of target batteries from at least a portion of the test conditions in the degradation rate map. The system provides the following steps: extract combinations of test conditions; in the degradation rate calculation step, calculate the degradation rate corresponding to each test condition for each combination based on a reference degradation rate map; in the generation step, generate a virtual degradation rate map, which is a virtual degradation rate map corresponding to the combination, based on the test conditions and degradation rates; in the comparison step, compare the trend of change in the reference degradation rate map in response to changes in test conditions with the trend of change in each capacity degradation rate of the virtual degradation rate map; and in the output step, based on the comparison result between the trend of change in the reference degradation rate map in response to changes in test conditions and the trend of change in each capacity degradation rate of the virtual degradation rate map, output the combination of test conditions corresponding to the virtual degradation rate map as the initial test conditions for the degradation test of the target battery.

[0009] With this configuration, it is possible to prioritize obtaining relatively reliable interval capacities from a given operational history data set. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram showing the configuration of information processing system 1. [Figure 2] This is a block diagram showing the hardware configuration of the information processing device 2. [Figure 3] This is a block diagram showing the hardware configuration of user terminal 3. [Figure 4] It is a diagram illustrating an example configuration of a deterioration testing apparatus 4. [Figure 5] It is a flowchart showing a flow of information processing for generating a deterioration rate map. [Figure 6] It is a flowchart illustrating an example of an initial test condition output process. [Figure 7] It is a diagram representing an example of a change tendency of a capacity deterioration rate with respect to a change in central SOC under a condition where other condition parameters are fixed in a certain deterioration rate map. [Figure 8] It is a diagram representing an example of a change tendency of a capacity deterioration rate with respect to a change in temperature under a condition where other condition parameters are fixed in a certain deterioration rate map. MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Various characteristic items shown in the embodiments described below can be combined with each other.

[0012] Incidentally, a program for implementing software appearing in one embodiment may be provided as a non-transitory computer-readable medium that can be read by a computer, may be provided so as to be downloadable from an external server, or may be provided such that the program is executed by an external computer to implement the function at a client terminal (so-called cloud computing).

[0013] Furthermore, in various information processing according to one embodiment, an input and an output corresponding to the input can be realized. Here, as long as an output is obtained as a result of the input, the form of the information referenced in such information processing (hereinafter referred to as reference information) is not limited. The reference information may be, for example, rule-based information such as a database, a lookup table, or a predetermined function (including a decision formula such as a regression equation constructed by a statistical method), or a trained model that has been pre-trained to learn the correlation between input and output, or a generative AI such as a large-scale language model or visual language model that can output a desired result by inputting a prompt.

[0014] Furthermore, in one embodiment, "part" may include, for example, hardware resources implemented by a circuit in a broad sense, and the information processing of software that can be specifically realized by these hardware resources. Also, in one embodiment, various types of information are handled, and this information can be represented, for example, by the physical values ​​of signal values ​​representing voltage and current, the high or low values ​​of signal values ​​as a set of binary bits composed of 0s or 1s, or by quantum superposition (so-called qubits), and communication and calculations can be performed on a circuit in a broad sense.

[0015] Furthermore, a circuit in a broad sense is a circuit realized by combining at least a suitable combination of circuits, circuits, processors, and memory. The processor may be a general-purpose processor or a dedicated circuit. In other words, it includes application-specific integrated circuits (ASICs), programmable logic devices (for example, simple programmable logic devices (SPLDs), complex programmable logic devices (CPLDs), and field programmable gate arrays (FPGAs)), etc.

[0016] 1. Hardware Configuration This section describes the hardware configuration.

[0017] <Information Processing System 1> Figure 1 is a diagram showing the configuration of information processing system 1. Information processing system 1 comprises an information processing device 2, a user terminal 3, and a degradation testing device 4. The information processing device 2, the user terminal 3, and the degradation testing device 4 are configured to communicate with each other via a telecommunications line. In one embodiment, information processing system 1 consists of one or more devices or components. For example, if it consists only of the information processing device 2, then information processing system 1 can be the information processing device 2. These components will be described below.

[0018] <Information Processing Device 2> Figure 2 is a block diagram showing the hardware configuration of the information processing device 2. The information processing device 2 comprises a communication unit 21, a storage unit 22, and a processor 23, and these components are electrically connected within the information processing device 2 via a communication bus 20. Each component will be described further.

[0019] The communication unit 21 preferably uses wired communication methods such as USB, IEEE1394, Thunderbolt®, and wired LAN network communication, but may also include wireless LAN network communication, mobile communication such as 3G / LTE / 5G, and Bluetooth® communication as needed. In other words, it is more preferable to implement it as a collection of these multiple communication methods. That is, the information processing device 2 may communicate various information from the outside via the communication unit 21 and the network.

[0020] The memory unit 22 stores various types of information as defined above. This can be implemented, for example, as a storage device such as a solid-state drive (SSD) that stores various programs related to the information processing device 2 executed by the processor 23, or as memory such as random access memory (RAM) that stores temporarily necessary information (arguments, arrays, etc.) related to program calculations. The memory unit 22 stores various programs and variables related to the information processing device 2 executed by the processor 23.

[0021] The processor 23 performs processing and control of the overall operation related to the information processing device 2. The processor 23 is, for example, a central processing unit (CPU) not shown. The processor 23 realizes various functions related to the information processing device 2 by reading predetermined programs stored in the memory unit 22. That is, information processing by software stored in the memory unit 22 can be concretely realized by the processor 23, which is an example of hardware, and executed as each functional unit included in the processor 23. These will be described in more detail in the next section. Note that the processor 23 is not limited to being a single unit, and may be implemented with multiple processors 23 for each function, or a combination thereof.

[0022] For example, the processor 23 is configured to acquire information from the user terminal 3 or other devices. The processor 23 is configured to acquire various information by reading various information stored in the storage area, which is at least a part of the memory unit 22, and writing the read information to the work area, which is at least a part of the memory unit 22. The storage area is, for example, the area of ​​the memory unit 22 that is implemented as a storage device such as an SSD. The work area is, for example, the area that is implemented as memory such as RAM. The acquisition by the processor 23 includes acquiring the output results of each functional unit included in the processor 23.

[0023] Furthermore, the processor 23 may be configured to display various types of information. This information can be presented to the user via the display unit 34 of the user terminal 3 or other devices, as described later. In such a case, for example, the processor 23 controls the display unit 34 of the user terminal 3 to display visual information such as screens, images including still images or videos, icons, and messages. The processor 23 may generate only rendering information for displaying the visual information on the user terminal 3. The processor 23 may also present the outputted information to the user without going through the user terminal 3 or other devices.

[0024] <User Terminal 3> Figure 3 is a block diagram showing the hardware configuration of the user terminal 3. The user terminal 3 comprises a communication unit 31, a storage unit 32, a processor 33, a display unit 34, and an input unit 35, and these components are electrically connected within the user terminal 3 via a communication bus 30. The descriptions of the communication unit 31, storage unit 32, and processor 33 are the same as the descriptions of each part in the information processing device 2, so they are omitted here.

[0025] The display unit 34 may be included in the user terminal 3 housing or it may be an external component. The display unit 34 displays a graphical user interface (GUI) screen that can be operated by the user. This is preferably done by using different display devices such as a CRT display, liquid crystal display, organic EL display, and plasma display, depending on the type of user terminal 3.

[0026] The input unit 35 is configured to accept input from the user. The input unit 35 may be included in the casing of the user terminal 3 or it may be an external component. For example, the input unit 35 may be integrated with the display unit 34 and implemented as a touch panel. If it is a touch panel, the user can input tap operations, swipe operations, etc. Of course, instead of a touch panel, a switch button, mouse, QWERTY keyboard, voice recognition device, gesture detection device, gaze detection device, biosignal detection device, imaging device, etc. may be used. In other words, the input unit 35 accepts operation input made by the user. In response, the input unit 35 transmits a signal corresponding to the operation input to the processor 33 via the communication bus 30. The processor 33 can perform predetermined controls and calculations as needed. The input unit 35 may also be a human-machine interface device.

[0027] <Degradation Testing Apparatus 4> Figure 4 shows an example of the configuration of the degradation test apparatus 4. The degradation test apparatus 4 comprises at least one constant temperature chamber 41 and a charge / discharge device 42, and these components are configured to communicate with each other.

[0028] Each constant temperature chamber 41 houses a secondary battery B and is configured to allow degradation testing to be performed on multiple secondary batteries B in parallel by controlling the temperature of the secondary batteries B. The secondary battery B can be any battery that is capable of charging and discharging, such as a lead-acid battery, nickel-cadmium battery, lithium-ion battery, or air battery.

[0029] The charge / discharge device 42 is configured to perform a degradation test on the secondary battery B by controlling the operation of the constant temperature chamber 41 and the secondary battery B. The charge / discharge device 42 is configured to control the temperature of the constant temperature chamber 41 according to the test conditions of the degradation test. The charge / discharge device 42 is also configured to control the charging and discharging manner of the secondary battery B, such as the charge / discharge rate of the secondary battery B, and the voltage and current during charging and discharging, according to the test conditions. The charge / discharge device 42 is also configured to measure the voltage of each secondary battery B.

[0030] Test conditions can be expressed using multiple condition parameters. For example, condition parameters are parameters related to the control target value when controlling the degradation test apparatus 4 for performing degradation tests. With such a configuration, test conditions can be set in relation to the control of the degradation test apparatus 4, making it possible to search for initial test conditions that are more convenient in relation to degradation tests. As an example, condition parameters defining the test conditions may include the test time for performing the degradation test, the temperature of the constant temperature chamber 41 (in other words, the temperature of the secondary battery B), the current rate of the secondary battery B, the average SOC (State of Charge), the center SOC, and the SOC width. These elements defining the test conditions are used as elements of the state space representing the test conditions when generating the degradation rate map described later. Note that the test conditions may also include elements other than those mentioned above as elements of such a state space. For example, the test conditions may include the temperature control rate of the constant temperature chamber 41, the temperature control time, and the waiting time when the target SOC is reached.

[0031] The test conditions are set within a predetermined test range. The test range includes, for example, the temperature range of the constant temperature chamber 41, the current rate range of the secondary battery B, the average SOC range, and the SOC width value.

[0032] 3. Regarding information processing This section describes the information processing performed in the aforementioned information processing system 1. Note that this information processing may include any exception handling not shown in the following diagram. Exception handling includes interrupting the information processing or omitting certain processes. The selections or inputs made in this information processing may be based on user operation or performed automatically without user operation. Furthermore, in this information processing, the information processing device 2 uses the degradation testing device 4 to perform degradation tests and various electrical measurements on the secondary battery B. For the sake of explanation, the (secondary) battery B that is the subject of the degradation test will be referred to as target battery B below.

[0033] 3.1. Overview of Information Processing First, an overview of the present information processing will be described. FIG. 5 is a flowchart showing the flow of information processing for generating a deterioration rate map.

[0034] [Step S1] As shown in FIG. 5, the processor 23 executes an initial test condition output process, and outputs initial test conditions, which are the test conditions for a deterioration test initially performed on the target battery B. Details of the initial test condition output process will be described later.

[0035] [Step S2] Next, in step S2, the processor 23 uses the charging / discharging device 42 to determine the initial capacity C of the target battery B ini and measures it. Note that each target battery B is an unused product. The initial capacity C ini can be measured by any arbitrary method. For example, the processor 23 uses the constant temperature bath 41 to leave each target battery B in a temperature environment around room temperature for a certain period of time. Thereafter, the processor 23 uses the nominal capacity C of each target battery B nominal to calculate the discharge current I at which the current rate is 0.1C 01C . The magnitude of the discharge current I 01C is, for example, I 01C =C nominal calculated by the relational expression ×0.1. Thereafter, the processor 23 subjects the target battery B set in each constant temperature bath 41 to constant current constant voltage charging (CCCV charging) up to 100% SOC with the discharge current I 01C , suspends charging and discharging for a certain period, then performs constant current constant voltage discharging until the SOC reaches 0%. The processor 23 stores the discharge capacity obtained by such discharging as the initial capacity C of each target battery B ini in the storage unit 22.

[0036] Next, in step S3, the processor 23 uses the constant temperature bath 41 and the charging / discharging device 42 to execute a deterioration test on each target battery B based on the set test conditions. For example, the processor 23 controls the temperature of the constant temperature bath 41 so as to reach the test temperature specified in the test conditions, and charges and discharges each target battery B using the charging / discharging device 42.

[0037] [Step S4] Next, in step S4, the processor 23 performs a degradation test based on the initial test conditions output in step S1.

[0038] [Step S5] Next, in step S5, the processor 23 measures the capacity C of the target battery B after the degradation test in step S4.

[0039] [Step S6] Next, in step S6, the processor 23 has an initial capacity C ini The capacity degradation rate is calculated based on the capacity C after the degradation test. The calculated capacity degradation rate is stored in the storage unit 22 in correspondence with the test conditions of the degradation test.

[0040] [Step S7] Next, in step S7, the processor 23 estimates a degradation rate map based on the test conditions of the executed degradation test (initial test conditions in the first loop) and the calculated degradation rate. The degradation rate map shows the relationship between the test conditions of the secondary battery and the capacity degradation rate of the secondary battery. The representation format of the degradation rate map can be arbitrary, such as a function, a lookup table, or a trained model. If an existing degradation rate map exists, the processor 23 may update the existing degradation rate map with the newly generated degradation rate map.

[0041] [Step S8] Next, in step S8, the processor 23 determines whether or not to terminate the degradation test based on predetermined degradation test termination conditions. The degradation test termination conditions are met, for example, when information related to the degradation rate map, such as the accuracy of the degradation rate map and the number of data points, meets the specified conditions. The degradation test termination conditions may also be met by receiving input from the user indicating the termination of the test, or by performing a specified number of degradation tests.

[0042] [Step S9] If it is determined that the termination conditions are met, the process proceeds to step S8, and the processor 23 outputs the latest degradation rate map. This degradation rate map can be stored, for example, in a battery management system (BMS) of the same secondary battery as the target battery B, and can be used for managing the state of the secondary battery and controlling charging and discharging. After that, the processor 23 terminates this information processing.

[0043] [Step S21] On the other hand, if it is determined that the termination conditions are not met, the process proceeds to step S21, and the processor 23 searches for the next test conditions for all target batteries B. The next test conditions may be appropriately selected from, for example, a predetermined list of test conditions, or they may be selected based on the distribution of tested test conditions in the degradation rate map estimated up to the previous step. After that, the process returns to step S2, and the processor 23 sets the next test conditions for each target battery B based on the search results. Here, the next test conditions can be set more efficiently from various viewpoints such as accuracy and test time by taking into account the capacity degradation rate estimated immediately beforehand.

[0044] [Step S22] Subsequently, in step S22, the processor 23 performs a degradation test based on the newly set test conditions. Then, returning to step S4, the processor 23 sequentially calculates the capacity, capacity degradation amount, and capacity degradation rate of the target battery B, and repeatedly updates the degradation rate map until the termination conditions are met.

[0045] By repeating this process, the degradation rate map can be updated sequentially, resulting in a more accurate degradation rate map.

[0046] 3.2. Example of initial test condition output processing Next, we will explain an example of the initial test condition output process in step S1, as described in the previous section. Figure 6 is a flowchart of an example of the initial test condition output process.

[0047] [Step S11] As shown in Figure 6, in step S11, the processor 23 first acquires battery information regarding the configuration of the target battery B and number information regarding the number of the target battery B. The battery information may include any information that can correlate with the electrical characteristics of the battery, such as information about the battery's electrolyte, information about the battery's package, and electrode information regarding the materials that make up the electrodes of the target battery B. The electrode information may include, for example, information that the electrodes have a specific configuration (e.g., that they are a ternary lithium-ion battery or an LFP lithium-ion battery) and information about the elements contained in the electrodes. The electrode information may include information about the positive electrode in particular. The battery information can be entered by the user as appropriate, for example.

[0048] [Step S12] Next, in step S21, the processor 23 identifies a reference degradation rate map based on the electrode information and the degradation rate map for the reference battery.

[0049] The degradation rate map for the reference battery may be, for example, a degradation rate map generated from degradation tests previously conducted on the reference battery, or a degradation rate map estimated through theoretical simulations of the reference battery, and may be stored in a device that can function as a database of degradation rate maps, such as the memory unit 22. The degradation rate map for the reference battery is associated with, for example, the underlying information obtained (e.g., the name of the reference battery, the specifications of the reference battery, information about the electrodes of the reference battery, etc.).

[0050] The reference degradation rate map is a degradation rate map used for comparison when estimating the degradation rate map of the target battery B. The reference degradation rate map can be the degradation rate map of the reference battery, or any other degradation rate map that can be obtained experimentally or theoretically with respect to the reference battery. The reference battery can be a physical object or a virtual one in a simulation.

[0051] For example, the processor 23 identifies a degradation rate map obtained from a degradation test on a reference battery having a certain degree of common configuration as a reference degradation rate map, based on the battery information acquired in step S11. Alternatively, if a degradation rate map obtained from a degradation test on a reference battery having the same type of electrodes is not stored in the memory unit 22, etc., the processor 23 may identify a degradation rate map (degradation rate formula) based on a known degradation rate map or electrochemical theory relating to a reference battery having relatively similar electrochemical properties, based on the battery information acquired in step S11. In one embodiment, the processor 23 can identify a reference degradation rate map based on a degradation rate map relating to a reference battery having a relationship with the materials constituting the electrodes of the target battery B. With such a configuration, it is possible to search for initial test conditions that make it easier to obtain a virtual degradation rate map that is close to a reference degradation rate map having electrochemical properties similar to those of the target battery B. Therefore, for example, compared to performing a degradation test from initial test conditions that make it easier to obtain a reference degradation rate map having completely different electrochemical properties and obtaining a degradation rate map of the target battery B, a more reliable degradation rate map can be obtained in a shorter time. For example, if the positive electrode of the target battery B is made of a new material containing lithium ions, the processor 23 may identify a degradation rate map relating to a reference battery having a lithium-ion-containing positive electrode such as an LFP as the reference degradation rate map.

[0052] [Step S13] Next, in step S13, the processor 23 extracts a number of test condition combinations corresponding to the number of target batteries B from at least a portion of the test conditions in the degradation rate map. The extracted test condition combinations become candidates for initial test conditions. For the sake of explanation, here we adopt temperature, center SOC, and current rate as three condition parameters for the test conditions, and there are all combinations of 4 temperatures, 4 center SOCs, and 6 current rates, resulting in a total of 96 possible values ​​that can be taken as candidates for test conditions for one target battery B. If there are 5 target batteries B, the processor 23 selects 5 test conditions from the above 96 candidate test conditions. In this case, the total number of candidate initial test conditions for the 5 target batteries B is96 There are C5 possibilities. For example, from the viewpoint of improving the efficiency of searching for initial test conditions, the processor 23 may extract combinations of test conditions such that the values ​​of each of the multiple condition parameters do not overlap with each other. With such a configuration, the possibility that the initial test conditions are locally optimized only within a narrow range of test conditions can be reduced. Specifically, for example, the processor 23 extracts test conditions to be assigned to five target batteries B such that the constraint condition "assign a different current rate to each of the five target batteries B" is satisfied. Note that the number of condition parameters is not limited to this and is arbitrary; it may be one, two, or four or more.

[0053] The test conditions may include conditions belonging to the storage degradation region where the current rate of the target battery B is zero, and conditions belonging to the charge / discharge degradation region where the current rate of the target battery B is other than zero. In this embodiment, the conditions belonging to the storage degradation region represent conditions corresponding to the natural discharge state when the target battery B is stored without being used. On the other hand, the conditions belonging to the charge / discharge degradation region represent conditions under which the target battery B is used to perform charging and discharging.

[0054] Subsequently, the processor 23 performs the following steps S14 to S18 on the extracted candidate initial test conditions to calculate the evaluation value of each test condition and output the optimal initial test condition. For the sake of explanation, the extracted in step S13 is used here. 96 An evaluation value will be calculated for each of the C5 candidate initial test conditions. The process from steps S14 to S18 will be explained below.

[0055] [Step S14] First, in step S14, the processor 23 calculates the capacity degradation rate corresponding to each test condition for each combination based on the reference degradation rate map. For example, the processor 23 first inputs the five test conditions that make up the combination into the reference degradation rate map and calculates the five capacity degradation rates corresponding to each test condition.

[0056] [Step S15] Next, in step S15, the processor 23 generates a virtual degradation rate map based on the test conditions and the capacity degradation rate. The virtual degradation rate map is a virtual degradation rate map corresponding to a combination of test conditions. For example, the processor 23 uses the five capacity degradation rates calculated in step S14 to estimate the degradation rate across the entire state space constituting the test conditions, and generates a virtual degradation rate map from the capacity degradation rates for that state space. The method for estimating the capacity degradation rate is arbitrary, but it can be implemented using any algorithm, such as Gaussian process regression, support vector machines (SVMs), or neural networks. The virtual degradation rate map can also be described as a provisional initial degradation rate map that can be estimated when a degradation test is performed on each of the target batteries B based on the initial test conditions.

[0057] Subsequently, the processor 23 compares the trend of change in the reference degradation rate map with the trend of change in the respective capacity degradation rates of the virtual degradation rate map, for example, through the processing in steps S16 to S18.

[0058] [Step S16] Next, in step S16, the processor 23 calculates a first partial evaluation value based on the trend of change in the reference degradation rate map in the storage degradation region and the trend of change in the virtual degradation rate map. The first partial evaluation value indicates the similarity between the trend of change in the reference degradation rate map in the storage degradation region and the trend of change in the virtual degradation rate map for each test condition.

[0059] Here, we will explain an example of a method for calculating the first partial evaluation value.

[0060] First, the processor 23 is defined by a set of n+1 condition parameters (current rate, temperature, central SOC) = (0, T) which consists of central SOCs extracted at equal intervals at multiple fixed temperatures in the region where the current rate is zero. fix SOC i Prepare the following, where the subscript i is an integer from 0 to n.

[0061] Next, the processor 23 inputs a set of n condition parameters to each of the reference degradation rate map and the virtual degradation rate map, and calculates the capacity degradation rate under the test conditions represented by the set of condition parameters. As a result, the processor 23 obtains two sequences {V1,...,V2} from each of the reference degradation rate map and the virtual degradation rate map that represent the capacity degradation rates for the n test conditions. n},{V1',...V n The result is obtained. The order of the sequence is sorted in ascending or descending order such that the input condition parameter (in this case, the central SOC) is common to both sequences.

[0062] Next, the processor 23 converts each of the two obtained vectors into difference vectors d and d'. The difference vectors d and d' are vectors that represent the trend of change in the rate of capacity degradation with respect to a certain condition parameter, and are defined, for example, as follows.

[0063]

number

[0064] In the formula, k is an integer from 1 to n.

[0065] Next, the processor 23 calculates an index relating to the similarity of the two obtained difference vectors d and d'. As the index, for example, the cosine similarity of the two difference vectors d and d' (hereinafter simply referred to as similarity) may be used, but is not limited to this. For example, the index may be an index representing distance (e.g., Manhattan distance, Euclidean distance). The processor 23 adds the obtained index to the first partial evaluation value. Here, the initial value of the first partial evaluation value is set to zero. After that, the processor 23 repeats the above calculation by changing the temperature and calculates the similarity for each temperature. The processor 23 performs this process for all temperatures to be considered and sums up the calculated similarities to calculate the similarity of the trend of change in the capacity degradation rate with respect to the change in the SOC center across the entire temperature range (for convenience of explanation, referred to as the first temperature similarity).

[0066] Next, the processor 23 has a set of m+1 condition parameters (current rate, temperature, center SOC) = (0, T) defined by temperatures extracted at equal intervals at multiple fixed center SOCs in the region where the current rate is zero. j SOC fix Prepare the following, where the subscript j is an integer from 0 to m.

[0067] Subsequently, the processor 23 calculates difference vectors d and d' for the change in temperature, following the same procedure as when the temperature similarity was calculated, and calculates the similarity of the trend of change in the capacity degradation rate with respect to the change in the central SOC at different temperatures (for convenience of explanation, this will be referred to as the first SOC similarity).

[0068] Subsequently, the processor 23 calculates a first partial evaluation value based on the first temperature similarity and the first SOC similarity. In this embodiment, the processor 23 calculates the first partial evaluation value by summing the first temperature similarity and the first SOC similarity, but the calculation method is arbitrary.

[0069] In this way, the processor 23 calculates the similarity of the difference vectors d and d' for each of the multiple condition parameters other than the current rate, and calculates a first partial evaluation value by summing the similarities calculated for each condition parameter.

[0070] [Step S17] Next, in step S17, the processor 23 calculates a second partial evaluation value based on the trend of change in the reference degradation rate map in the charge / discharge degradation region and the trend of change in the virtual degradation rate map. The second partial evaluation value indicates the similarity between the trend of change in the reference degradation rate map in the charge / discharge degradation region and the trend of change in the virtual degradation rate map for each test condition. The method for calculating the second partial evaluation value is arbitrary, but in this embodiment, the current rate, which was fixed at zero when calculating the first partial evaluation value, is treated as one of the condition parameters that are changed in the same way as temperature and central SOC, and the similarity of the trend of change in the capacity degradation rate for each change in each condition parameter (here, for temperature, this is called the second temperature similarity, for central SOC, this is called the second SOC similarity, and for current rate, this is called the charge / discharge similarity) is calculated, and the second partial evaluation value is calculated by summing them up. The first temperature similarity, first SOC similarity, second temperature similarity, second SOC similarity, and charge / discharge similarity are examples of parameter evaluation values ​​calculated from the comparison of the trends in the degradation rates of the reference degradation rate map and the virtual degradation rate map when some of the multiple condition parameters are changed.

[0071] [Step S18] Next, in step S18, the processor 23 calculates an evaluation value based on the first partial evaluation value and the second partial evaluation value. In other words, the processor 23 calculates an evaluation value based on the trend of change in the degradation rates of the reference degradation rate map and the virtual degradation rate map in response to changes in the test conditions. The evaluation value shows the similarity between the trend of change in the reference degradation rate map and the trend of change in the virtual degradation rate map for each test condition. With such a configuration, initial test conditions can be explored more appropriately. In this embodiment, the processor 23 calculates an evaluation value by summing the first partial evaluation value and the second partial evaluation value, but when calculating the evaluation value, the first partial evaluation value and the second partial evaluation value may have an asymmetrical contribution to the evaluation value, for example, by being weighted differently. In other words, the evaluation value is calculated based on the first partial evaluation value and the second partial evaluation value. From another perspective, the evaluation value is calculated based on parameter evaluation values ​​calculated for each of the multiple condition parameters.

[0072] In this way, the processor 23 calculates the similarity of the difference vectors d and d' for each of the multiple condition parameters other than the current rate, calculates a first partial evaluation value and a second partial evaluation value by summing the similarities calculated for each condition parameter, and calculates an evaluation value based on the first partial evaluation value and the second partial evaluation value.

[0073] The processor 23 performs the processes described in steps S14 to S18 above for all of the extracted initial test condition candidates and calculates an evaluation value for each of the initial test condition candidates.

[0074] [Step S19] Subsequently, in step S19, the processor 23 outputs a combination of test conditions corresponding to the virtual degradation rate map as the initial test conditions for the degradation test of the target battery B, based on the comparison result between the change trend of the reference degradation rate map in response to changes in test conditions and the change trend of the respective capacity degradation rates of the virtual degradation rate map. With this configuration, it is possible to identify initial test conditions that make it easier to obtain a virtual degradation rate map that is close to the reference degradation rate map that reflects the degradation trend of the battery under test, thereby shortening the time required to estimate the capacity degradation rate map of the target battery B from the degradation test results. For example, the processor 23 outputs a combination of test conditions corresponding to a virtual degradation rate map whose evaluation value calculated in step S18 satisfies the specified optimization conditions as the initial test conditions. With this configuration, it is easier to obtain the user-desired optimal initial test conditions according to the evaluation value.

[0075] In this embodiment, the optimization condition is "the evaluation value is the highest among the calculated evaluation values." The specific form of the optimization condition is not limited to this, and may include, for example, "the evaluation value is greater than the reference value." If multiple initial test conditions are output, the processor 23 may request the user to specify which of the multiple initial test conditions to use first.

[0076] 3.3. Relationship between difference vectors and the trend of change in capacity degradation rate Next, we will illustrate the relationship between the difference vector d and the trend of change in the capacity degradation rate. Figure 7 shows an example of the trend of change in the capacity degradation rate with respect to the change in central SOC under conditions where other condition parameters are fixed in a certain degradation rate map. As shown in Figure 7, the capacity degradation rate tends to increase as the central SOC increases, and the amount of increase also tends to gradually become larger. The difference vector d takes on a larger value as the index k increases, which can describe this trend.

[0077] Figure 8 shows an example of the trend of change in the capacity degradation rate with respect to temperature changes under conditions where other condition parameters are fixed in a certain degradation rate map. In the example shown in Figure 8, unlike the example shown in Figure 7, the capacity degradation rate shows a quadratic, downward-convex trend with respect to increasing temperature. This downward-convex trend can be described by the difference vector d taking values ​​that change in sign midway through as the index k increases.

[0078] 4. Others The above embodiment is merely an example and is not limited thereto.

[0079] The method for calculating the evaluation value is as follows: the difference vectors d and d' are each the rate of change V. k ,V k It may also be defined by taking the difference of the derivatives of '. In this case, the processor 23 can compare the trends of change of the two degradation rate maps from the curvature of the two degradation rate maps.

[0080] Furthermore, the comparison between the reference degradation rate map and the virtual degradation rate map is not limited to the method using the evaluation values ​​described above. For example, the processor 23 may compare the two degradation rate maps using a pre-trained model that has been trained to determine the similarity of functions and maps.

[0081] In the above embodiment, the processor 23 extracted all candidate initial test conditions in step S13 and calculated an evaluation value for each of the candidate initial test conditions. However, the processor 23 may also partially extract (for example, one) candidate initial test conditions from the state space that defines the entire range of candidate initial test conditions, calculate an evaluation value for that candidate initial test condition, and then sequentially search for and extract the next candidate initial test condition based on the evaluation result, thereby comparing the evaluation values ​​of multiple candidate initial test conditions. In other words, candidate initial test conditions may be extracted multiple times. With such a configuration, the search time for initial test conditions can be shortened. Examples of methods for searching for candidate initial test conditions include any optimization algorithm such as local search, sequential improvement, nearest neighbor search, cuckoo search, genetic algorithm, and particle swarm optimization.

[0082] The information processing device 2 may be on-premise or in a cloud-based configuration. In the case of a cloud-based information processing device 2, for example, the above-mentioned functions and processing may be provided in the form of SaaS (Software as a Service) or cloud computing.

[0083] In the above embodiment, the information processing device 2 performed various storage and control functions, but instead of the information processing device 2, multiple external devices may be used. That is, various information and programs may be stored in a distributed manner across multiple external devices using blockchain technology or the like.

[0084] The above embodiment is not limited to the information processing system 1, but may also be an information processing method or a program. The information processing method includes each step of the information processing system 1. The program causes at least one computer to execute each step of the information processing system 1.

[0085] The above-mentioned information processing system 1, etc., may be provided in any of the following embodiments.

[0086] (1) An information processing system comprising at least one processor, the processor configured to execute a program such that the following steps are performed: an acquisition step, which acquires battery information relating to the configuration of a target battery which is a battery to be tested for degradation, and information relating to the number of the target battery; an identification step, which identifies a reference degradation rate map based on the battery information and a degradation rate map relating to a reference battery different from the target battery, the degradation rate map showing the relationship between the test conditions of the battery and the capacity degradation rate of the battery under those test conditions, the reference degradation rate map being a degradation rate map used for comparison when estimating the initial degradation rate map of the target battery; and an extraction step, which extracts a number of test conditions corresponding to the number of the target battery from at least a portion of the test conditions in the degradation rate map. A system that extracts combinations, calculates the degradation rate corresponding to each of the test conditions for each combination based on the reference degradation rate map in the degradation rate calculation step, generates a virtual degradation rate map which is a virtual degradation rate map corresponding to the combination based on the test conditions and the degradation rate in the generation step, compares the trend of change of the reference degradation rate map in response to changes in the test conditions with the trend of change of each capacity degradation rate in the virtual degradation rate map in the comparison step, and outputs the combination of test conditions corresponding to the virtual degradation rate map as the initial test conditions which are the test conditions for the degradation test of the target battery, based on the comparison result of the trend of change of the reference degradation rate map in response to changes in the test conditions and the trend of change of each capacity degradation rate in the virtual degradation rate map in the output step.

[0087] With this configuration, it is possible to identify initial test conditions that make it easier to obtain a virtual degradation rate map that is close to a reference degradation rate map that reflects the degradation trend of the battery under test. This reduces the time required to estimate the capacity degradation rate map of the target battery from the degradation test results.

[0088] (2) In the information processing system described in (1) above, the comparison step calculates an evaluation value by comparing the trend of change of the reference degradation rate map with the trend of change of each capacity degradation rate of the virtual degradation rate map with respect to the change of the test conditions, the evaluation value indicates the similarity between the trend of change of the reference degradation rate map and the trend of change of each of the virtual degradation rate maps with respect to the test conditions, and the output step outputs a combination of test conditions corresponding to the virtual degradation rate map that satisfies the specified optimization conditions as the initial test conditions.

[0089] (3) In the information processing system described in (2) above, the test conditions are expressed by a plurality of condition parameters, and the evaluation value is calculated for each of the plurality of condition parameters based on a parameter evaluation value calculated from the comparison result of the change trends in the capacity degradation rate of the reference degradation rate map and the virtual degradation rate map when a part of the plurality of condition parameters is changed.

[0090] This configuration allows for a more effective exploration of initial test conditions.

[0091] (4) In the information processing system described in (3) above, the condition parameter is a parameter that is related to a control target value when controlling a degradation test apparatus for performing the degradation test.

[0092] With this configuration, test conditions can be set in conjunction with the control of the degradation testing device, making it possible to explore initial test conditions that are more convenient in relation to degradation testing.

[0093] (5) An information processing system according to any one of (2) to (4) above, wherein the test conditions include conditions belonging to a storage degradation region where the current rate of the target battery is zero, and conditions belonging to a charge / discharge degradation region where the current rate of the target battery is other than zero, and the evaluation value is calculated based on a first partial evaluation value and a second partial evaluation value, wherein the first partial evaluation value indicates the similarity between the change trend of the reference degradation rate map in the storage degradation region and the change trend of the virtual degradation rate map with respect to each of the test conditions, and the second partial evaluation value indicates the similarity between the change trend of the reference degradation rate map in the charge / discharge degradation region and the change trend of the virtual degradation rate map with respect to each of the test conditions.

[0094] (6) An information processing system described in any one of (1) to (5) above, wherein the test conditions are expressed by a plurality of condition parameters, and in the extraction step, a combination of the test conditions is extracted such that the values ​​of each of the plurality of condition parameters do not overlap with each other.

[0095] This configuration reduces the possibility that initial test conditions are locally optimized only within a narrow range of test conditions.

[0096] (7) An information processing system according to any one of (1) to (6) above, wherein the battery information includes electrode information relating to the materials constituting the electrodes of the target battery, the degradation rate map relating to the reference battery is associated with information relating to the materials constituting the electrodes of the reference battery, and in the identification step, the system identifies the reference degradation rate map based on the degradation rate map relating to the reference battery which is associated with the materials constituting the electrodes of the target battery.

[0097] With this configuration, it is possible to search for initial test conditions that make it easier to obtain a virtual degradation rate map that is close to a reference degradation rate map having electrochemical characteristics similar to those of the target battery. Therefore, compared to, for example, performing degradation tests from initial test conditions that make it easy to obtain a reference degradation rate map with completely different electrochemical characteristics and then obtaining the degradation rate map of the target battery, a more reliable capacity degradation rate map can be obtained in a shorter time.

[0098] (8) An information processing method comprising each step of an information processing system described in any one of (1) to (7) above.

[0099] (9) A program that causes at least one computer to perform each step of the information processing system described in any one of (1) to (7) above. Of course, this is not always the case.

[0100] Finally, while various embodiments relating to this disclosure have been described, these are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of Symbols]

[0101] 1: Information Processing System 2: Information Processing Device 20: Communications bus 21: Communications Department 22: Storage section 23: Processor 3: User terminal 30: Communications bus 31: Communications Department 32: Storage section 33: Processor 34: Display section 35: Input section 4: Degradation testing equipment 41: Constant temperature bath 42: Charge / discharge device B: Target battery

Claims

1. An information processing system, The system comprises at least one processor, the processor configured to execute a program such that the following steps are performed: In the acquisition step, information is obtained regarding the configuration of the target battery, which is the battery to be tested in the degradation test, and information regarding the number of such target batteries. In a specific step, a reference degradation rate map is identified based on the battery information and a degradation rate map relating to a reference battery different from the target battery. The aforementioned degradation rate map shows the relationship between the battery test conditions and the capacity degradation rate of the battery under those test conditions. The aforementioned reference degradation rate map is a degradation rate map used for comparison when estimating the initial degradation rate map of the target battery. In the extraction step, a number of test condition combinations corresponding to the number of target batteries are extracted from at least a portion of the test conditions in the degradation rate map. In the degradation rate calculation step, based on the reference degradation rate map, the degradation rate corresponding to each of the test conditions is calculated for each combination. In the generation step, a virtual degradation rate map, which is a virtual degradation rate map corresponding to the combination, is generated based on the test conditions and the degradation rate. In the comparison step, the trend of change in the reference degradation rate map in response to the change in the test conditions is compared with the trend of change in the respective capacity degradation rates of the virtual degradation rate maps. In the output step, the system outputs a combination of the test conditions corresponding to the virtual degradation rate map as the initial test conditions for the degradation test of the target battery, based on the comparison result between the trend of change of the reference degradation rate map in response to the change in the test conditions and the trend of change of the respective capacity degradation rates of the virtual degradation rate map.

2. In the information processing system described in claim 1, In the comparison step, an evaluation value is calculated by comparing the trend of change in the reference degradation rate map with the trend of change in the respective capacity degradation rates of the virtual degradation rate map in response to the change in the test conditions. The aforementioned evaluation values ​​show the similarity between the trend of change of the reference degradation rate map and the trend of change of the virtual degradation rate map with respect to each of the aforementioned test conditions. In the output step, the system outputs a combination of test conditions corresponding to the virtual degradation rate map in which the evaluation value satisfies the specified optimization conditions, as the initial test conditions.

3. In the information processing system described in claim 2, The aforementioned test conditions are expressed in terms of multiple condition parameters, The system calculates the evaluation value based on a parameter evaluation value obtained from a comparison of the trend of change in the capacity degradation rate of the reference degradation rate map and the virtual degradation rate map when a part of the multiple condition parameters is changed for each of the multiple condition parameters.

4. In the information processing system described in claim 3, The aforementioned condition parameters are parameters related to control target values ​​when controlling a degradation test apparatus for performing the degradation test, in a system.

5. In the information processing system described in claim 2, The aforementioned test conditions include conditions belonging to the storage degradation region where the current rate of the target battery is zero, and conditions belonging to the charge / discharge degradation region where the current rate of the target battery is other than zero. The aforementioned evaluation value is calculated based on the first partial evaluation value and the second partial evaluation value. The first partial evaluation value indicates the similarity between the trend of change of the reference degradation rate map in the storage degradation region and the trend of change of the virtual degradation rate map with respect to each of the test conditions. The system wherein the second partial evaluation value indicates the similarity between the trend of change of the reference degradation rate map in the charge-discharge degradation region and the trend of change of the virtual degradation rate map with respect to each of the test conditions.

6. In the information processing system described in claim 1, The aforementioned test conditions are expressed in terms of multiple condition parameters, The system extracts combinations of test conditions in the extraction step such that the values ​​of each of the multiple condition parameters do not overlap with each other.

7. In the information processing system described in claim 1, The battery information includes electrode information relating to the materials constituting the electrodes of the target battery, The degradation rate map for the aforementioned reference battery is associated with information about the materials constituting the electrodes of the reference battery, The system, in the specified step, identifies the reference degradation rate map based on the degradation rate map relating to the reference battery having a relationship with the materials constituting the electrodes of the target battery.

8. Information processing method, A method comprising each step of the information processing system described in any one of claims 1 to 7.

9. It is a program, A program that causes at least one computer to perform each step of the information processing system described in any one of claims 1 to 7.

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