Information processing apparatus, battery system, program, and method for processing information

Abstract

To provide an information processing apparatus, a battery system, a program, and a method for processing information which can realize long life of a battery module.SOLUTION: According to an embodiment, there is provided an information processing apparatus including a processing circuit for calculating a first evaluation index of a plurality of unit cells in a battery module and calculating a second evaluation index in a case where a first unit cell in the battery module and a second unit cell in the battery module are replaced with each other on the basis of the first evaluation index, the first evaluation index and the second evaluation index being calculated on the basis of a positive electrode potential and a temperature rise rate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to an information processing device, a battery system, a program, and an information processing method. [Background technology]

[0002] When single cells are used as a battery module, the rate of deterioration of each single cell varies depending on the installation position of the single cells, which may shorten the life of the battery module. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-095746 [Patent Document 2] International Publication No. 2015 / 151652 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide an information processing device, a battery system, a program, and an information processing method that can extend the life of a battery module. [Means for solving the problem]

[0005] According to an embodiment, an information processing device is provided that includes a processing circuit that calculates a first evaluation index for a plurality of unit cells in a battery module, and calculates a second evaluation index when a first unit cell in the battery module is swapped with a second unit cell in the battery module based on the first evaluation index, and the first evaluation index and the second evaluation index are calculated based on the positive electrode potential and the temperature rise rate. [Brief explanation of the drawings]

[0006] [Figure 1]FIG. 1 is a block diagram showing an example of a schematic configuration of a battery system according to an embodiment. [Figure 2] 3 is a flowchart showing an example of a battery diagnosis method according to the embodiment. [Figure 3] FIG. 10 is a block diagram showing a schematic modification of the battery system according to the embodiment. [Figure 4] 10 is a flowchart showing a modified example of the battery diagnosis method according to the embodiment. [Figure 5] FIG. 10 is a block diagram showing a schematic modification of the battery system according to the embodiment. [Figure 6] 10 is a flowchart showing a modified example of the battery diagnosis method according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments will be described with reference to the drawings. In the following description, components that perform the same or similar functions are designated by the same reference numerals throughout the drawings, and duplicate descriptions will be omitted. Each drawing is a schematic diagram for explaining and facilitating understanding of the embodiments, and the shapes, dimensions, ratios, etc. may differ from those of an actual device. However, these may be appropriately modified in design, taking into consideration the following description and known techniques.

[0008] A battery module is formed from two or more single cells of secondary batteries. The secondary batteries will be described below as lithium-ion secondary batteries. Each single cell has a positive electrode and a negative electrode as electrodes, and the positive electrode and negative electrode have opposite polarities to each other. The potential of each positive electrode and negative electrode of a single cell changes in response to changes in the state of charge. Each positive electrode and negative electrode has a predetermined relationship between the potential and the state of charge. Therefore, for each electrode of a secondary battery, the potential can be calculated based on the state of charge, and the state of charge can also be calculated based on the potential.

[0009] The information processing device according to this embodiment uses an evaluation index to evaluate the deterioration status of each unit cell in a battery module. The evaluation index quantifies the likelihood of occurrence of events that disrupt normal operation, such as unit cell deterioration or a rapid temperature rise due to the progression of deterioration. A high positive electrode potential of a unit cell facilitates chemical reactions, such as structural changes in the positive electrode active material and oxygen decomposition, which promote the desorption of lithium ions or the generation of metal ions, resulting in metal precipitation. Furthermore, as the temperature of a unit cell increases, the rates of both the charge / discharge reaction and the deterioration reaction of the battery increase, with the deterioration reaction accelerating more rapidly, resulting in further deterioration. Therefore, the present invention utilizes these properties and employs the positive electrode potential and temperature rise rate of a unit cell as evaluation indices.

[0010] (First embodiment) FIG. 1 is a block diagram showing an example of a schematic of a battery system according to an embodiment. In the embodiment, the battery system 1 includes an information processing device 3 and a single cell 4 (first single cell). The single cell 4 is included in a battery module 2. In addition to the single cell 4, the battery module 2 includes a measurement unit 5, a first storage medium 6, a control circuit 7, a charge / discharge circuit 8, and a first communication module 9. The measurement unit 5 includes a current measurement circuit 51 for the single cell 4, a voltage measurement circuit 52 for measuring the voltage, and a timer 54. The measurement unit 5 may further include a temperature sensor. The first storage medium 6 includes a first data management program 11 capable of managing data transfer and a battery measurement program 12 for measuring the SOC (State of Charge) and voltage of the single cell 4. The information processing device 3 includes a second storage medium 60, a processing circuit 17, and a second communication module 19. The information processing device 3 may further include a user interface 20. The second storage medium 60 stores a second data management program 61 that can manage data input and output, and a battery control program 70 that can control the single cell 4.

[0011] The battery control program 70 includes a potential calculation program 62A that calculates the positive electrode potential of the unit cell 4, a first temperature rise rate calculation program 62B that calculates the temperature rise rate of the unit cell 4, a first evaluation index derivation program 63 that derives first evaluation indices for all unit cells, a first cell extraction program 64 that extracts the unit cell with the largest evaluation index, a threshold comparison program 65 that compares the evaluation index of the extracted unit cell with a threshold, a second cell extraction program 66 that extracts the unit cell with the smallest evaluation index, a second evaluation index derivation program 67 that derives evaluation indices when the unit cell extracted by the first cell extraction program 64 and the unit cell extracted by the second cell extraction program 66 are virtually replaced, and a first replacement determination program 68 that compares the evaluation index derived by the second evaluation index derivation program 67 with a threshold. The battery control program 70 may further include a notification program 69 that notifies the user of the need to replace a unit cell or to replace it with a new unit cell. The programs included in the battery control program 70 do not need to be stored in the second storage medium 60. For example, the programs only need to be able to receive instructions for executing the programs issued from the processing circuit 17 and execute the programs. Therefore, the programs may be stored in separate storage media or run in the cloud.

[0012] Examples of the battery module 2 include large-scale power storage devices for power systems, smartphones, vehicles, stationary power supply devices, robots, drones, etc. Examples of vehicles that can be used as the battery module 2 include railcars, electric buses, electric cars, plug-in hybrid cars, and electric motorcycles. Any device that uses a secondary battery can be used.

[0013] The measurement unit 5 is capable of detecting and measuring parameters related to the single cell 4 at multiple measurement points, such as when the single cell 4 is being charged or discharged.

[0014] The current measurement circuit 51 acquires the current value of the single cell 4 .

[0015] The voltage measurement circuit 52 acquires the voltage value of the single cell 4 .

[0016] The timer 54 can measure the time when the parameters relating to the unit cell 4 are measured.

[0017] The first storage medium 6 is a storage device called a main storage device or an auxiliary storage device. Examples of the first storage medium 6 include a magnetic disk, an optical disk (CD-ROM, CD-R, DVD, etc.), a magneto-optical disk (MO, etc.), and a semiconductor memory. The battery module 2 may be provided with only one memory or multiple memories serving as the first storage medium 6. The first storage medium 6 stores data such as programs executed by the control circuit 7, data resulting from the execution of the programs, and measurement results from the measurement unit 5.

[0018] The control circuit 7 is configured with a processor or an integrated circuit, and the processor or the like that configures the control circuit 7 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or the like. Specific Integrated Circuit), Microcontroller The control circuit 7 may include any of a FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), etc. The control circuit 7 may be composed of one processor or multiple processors. The control circuit 7 reads and executes a program stored in the first storage medium 6, and controls charging and discharging of the unit cell 4 via the charge / discharge circuit 8. The control circuit 7 switches between a state in which the unit cell 4 is charged and a state in which the unit cell 4 is discharged, for example, by switching the state of the charge / discharge circuit 8. Furthermore, when the unit cell 4 is being charged, the control circuit 7 controls the driving of the power source 10 that supplies power to the unit cell 4 and the driving of the charge / discharge circuit 8, thereby adjusting the magnitude of the current input to the unit cell 4, etc.

[0019] The control circuit 7 reads and executes the battery measurement program 12 from the first storage medium 6 to measure the SOC of the single cell 4. The control circuit 7 can acquire measurement results of parameters related to the single cell 4, such as data on the current and voltage values ​​of the single cell 4, from the measurement unit 5, and input measurement data including these measurement results and data on the calculated SOC into the first storage medium 6. The control circuit 7 can also transmit data obtained by the battery measurement program 12 to the information processing device 3 via the first communication module 9. The measurement data includes measurement values ​​and changes (time history) at multiple measurement points. The measurement data may also include the change (time history) in the current of the single cell 4, the change (time history) in the voltage of the single cell 4, and the change (time history) in the temperature of the single cell 4. The processing circuit 17 of the information processing device 3 receives the data transmitted from the battery module 2 via the second communication module 19.

[0020] In the battery module 2, the control circuit 7, the first storage medium 6, etc. constitute a BMU (Battery Management Unit).

[0021] The charge / discharge circuit 8 is equipped with, for example, an AC / DC converter and a transformer circuit. In the charge / discharge circuit 8, the AC / DC converter or the like converts AC power from the power source 10 into DC power, and the transformer circuit or the like transforms the voltage of the power supplied from the power source 10 into a voltage suitable for the single cell 4. As a result, DC power is supplied to the single cell 4 at a voltage suitable for the single cell 4, and a charging current is input to the single cell 4.

[0022] The first communication module 9 is composed of a communication interface and the like of the battery module 2. The control circuit 7 is capable of communicating with processing devices external to the battery module 2, including the information processing device 3, via the first communication module 9.

[0023] The information processing device 3 is a processing device (computer) such as a server that is provided outside the battery module 2, and communicates with the first communication module 9 of the battery module 2 via the second communication module 19.

[0024] The second storage medium 60 included in the information processing device 3 is a storage device called a main storage device or an auxiliary storage device. For example, the information processing device 3 may be provided with only one storage device serving as the second storage medium 60, or may be provided with multiple storage devices.

[0025] The processing circuit 17 included in the information processing device 3 is composed of a processor or an integrated circuit, etc., and the processor constituting the processing circuit 17 may be any of a CPU, ASIC, microcomputer, FPGA, DSP, etc. The processing circuit 17 may be composed of one processor, etc., or may be composed of multiple processors, etc. The processing circuit 17 performs processing by executing programs, etc. stored in the second storage medium 60. In the example of FIG. 1 , the processing circuit 17 writes data to the second storage medium 60 and reads data from the second storage medium 60 by executing a second data management program 61. The processing circuit 17 also executes a battery control program 70 to perform the processing described below in controlling the single cell 4.

[0026] The second communication module 19 is composed of a communication interface of a processing device that constitutes the information processing device 3. The processing circuit 17 communicates with devices external to the information processing device 3, including the battery module 2, via the second communication module 19.

[0027] The user interface 20 can output information related to the information processing of the single cell 4 and can receive input related to the information processing of the single cell 4 from users of the information processing device 3 and the battery system 1. For this purpose, the user interface 20 is provided with an output device that outputs information related to the information processing of the single cell 4. The output device outputs information to the outside by displaying on a screen, emitting sound, vibrating, etc. Note that the output device can receive instructions from the processing circuit 17 and output information such as gas generation to the user. The user interface 20 is also provided with an input device that allows the user to input operations. The input device is composed of, for example, one or more of a button, a mouse, a touch panel and keyboard, a voice input device, etc. Note that the user interface 20 may be provided separately from the processing device that constitutes the information processing device 3.

[0028] The flow of the battery diagnostic method according to the embodiment will be described. FIG. 2 is a flowchart showing an example of the flow of the battery system according to the embodiment. Note that this flowchart is only an example, and the order of the processes is not limited as long as the required processing results can be obtained. Furthermore, each processing result may be stored sequentially in the second storage medium 60, and each step may acquire the processing result by referring to the second storage medium 60. The same applies to the subsequent flowcharts.

[0029] In S2A, the processing circuit 17 reads and executes the potential calculation program 62A to calculate the positive electrode potential of the unit cell 4. The positive electrode potential can be calculated, for example, by creating and analyzing a charge / discharge curve using the voltage and SOC.

[0030] In S2B, the processing circuit 17 reads and executes the first temperature rise rate calculation program 62B to calculate the temperature rise rate of the unit cell 4. The temperature rise rate can be calculated, for example, from the distance from the surface of the unit cell 4 to the surface of the battery module 2 and the thermal conductivity within the battery module 2. Specifically, the distance from the surface of each unit cell 4 to the surface of the battery module 2 is calculated in advance. The thermal conductivity can be calculated depending on the materials used in the unit cell 4 and the battery module 2. For example, the temperature rise rate increases as the distance from the surface increases and the thermal conductivity decreases. The temperature-related information acquired in S2B is determined by the arrangement of the unit cells 4 within the battery module 2 and is therefore not dependent on the performance of each unit cell 4.

[0031] In S3, the processing circuit 17 reads and executes the first evaluation index derivation program 63 to derive the first evaluation index for all the unit cells 4 in the battery module 2 from the positive electrode potential and the temperature rise rate.

[0032] The first and second evaluation indices are described below. Hereinafter, the first and second evaluation indices may be collectively referred to as the evaluation indices. The evaluation index is an index calculated based on the positive electrode potential and temperature rise rate of a single cell. The evaluation index can be defined as a numerical value that increases with increasing positive electrode potential and increasing temperature rise rate of the single cell. The evaluation index may also be a numerical value that decreases with increasing positive electrode potential and increasing temperature rise rate of the single cell. While the first and second evaluation indices are both derived using the positive electrode potential and temperature rise rate of the single cells in a battery module, the second evaluation index is a value obtained when the single cells are virtually swapped. The temperature rise rate is independent of the single cells but depends on their position within the battery module. Therefore, the temperature rise rate of the single cell in the assumed swap position is used to calculate the second evaluation index. For example, when swapping cells P and Q, the second evaluation index of cell P is calculated using the positive electrode potential of cell P and the temperature rise rate of cell Q.

[0033] The positive electrode potential of the single cell is v ij , the temperature rise rate of the single cell is tij , First evaluation index S ij Table 1 shows various values ​​of the single cells in the battery module 2 when calculating the first evaluation index.

[0034] [Table 1] In Table 1, there are 8 frames in the vertical direction i and 3 frames in the horizontal direction j, for a total of 24 frames. This table is considered a battery module, and each frame is considered a unit cell. In other words, 8 unit cells are arranged in the vertical direction i and 3 in the horizontal direction j, and 24 unit cells form one battery module. The values ​​in each frame indicate the positive electrode potential in Table 1(a), the temperature rise rate of the unit cell in Table 1(b), and the first evaluation index calculated using the function described below in Table 1(c). The first evaluation index is the value obtained multiplied by 100.

[0035] Generally, the higher the positive electrode potential of the single cell or the greater the rate of temperature rise, the more the deterioration of the single cell progresses. Therefore, it is desirable to express the evaluation index using an equation that can reflect the actual deterioration state of the single cell in detail, and it can be expressed using, for example, a function. First evaluation index S ij is the evaluation function F of the positive electrode potential v and the evaluation function F for the temperature rise rate of a single cell t Using this, it can be expressed as:

number

[0036] v ij is the positive electrode potential of the single cell, t ij is the temperature rise rate of the single cell, C t represents the weighting of the unit cell temperature (any positive number). The pair [i, j] represents the position of the unit cell in the battery module. In the case of an 8x3 unit cell arrangement, i is a value between 1 and 8, and j is a value between 1 and 3. Here, F v is expressed as follows:

number

[0037] v min is the positive electrode potential of an unused single cell, e.g., 4.17. t is expressed as follows:

number

[0038] t min is the minimum temperature rise rate in a single cell in the battery module 2.

[0039] In Table 1, consider the first evaluation index when [i, j] is, for example, [3, 2]. C t = 1.0, the first evaluation index S ij can be found as follows:

number

[0040] The definitions of the evaluation function for the positive electrode potential and the evaluation function for the temperature rise rate are not limited to those shown here. In addition, factors other than the positive electrode potential and the temperature rise rate can be added to calculate the evaluation index. For example, the probability of deformation due to impact d ij can be added to equation 2 to give:

number

[0041] Here, F d is the evaluation function of the deformation probability, and C d is the weighting of the transformation probability (any positive number).

[0042] In S4, the processing circuit 17 reads and executes the first cell extraction program 64 to extract the unit cell (first unit cell) with the largest first evaluation index from the results calculated in S3. This is designated as cell X, and the first evaluation index of cell X is S x Let's say.

[0043] The evaluation index can also be calculated based on the correspondence between the positive electrode potential of the single cell and the temperature rise rate. As an example of the correspondence, a table format can be used.

[0044] In the table format, for example, the vertical axis is assigned to the positive electrode potential and the horizontal axis to the temperature rise rate. A predetermined evaluation index is set at the intersection of a certain value of the positive electrode potential and a certain value of the temperature rise rate. This is called a correspondence table. The values ​​of the evaluation index in the correspondence table can be set arbitrarily, but it is desirable that they correspond to previously acquired data on the positive electrode potential and temperature rise rate of a single cell. Because the values ​​of the positive electrode potential and temperature rise rate in the table are discrete, it is desirable to fill in the blanks using, for example, linear interpolation. The correspondence table makes it easier to reflect phenomena that may occur in an actual battery module, such as variations in temperature change depending on position. While it is possible to obtain an equation using the positive electrode potential and temperature rise rate, the information that other factors contribute to the evaluation index is somewhat reduced. Therefore, by using the correspondence table, it is possible to set the evaluation index by taking into account factors other than the positive electrode potential and temperature rise rate that affect the calculation of the evaluation index. Furthermore, it is desirable that the ranges of the positive electrode potential and temperature rise rate in the correspondence table include values ​​that are likely to be observed by a single cell. The vertical and horizontal axes of the correspondence table can be interchanged. The evaluation index for one unit cell is calculated by referring to the correspondence table and selecting the evaluation index when the positive electrode potential and temperature rise rate of the unit cell calculated in S2A and S2B are taken. This operation is performed for all unit cells in the battery module 2. By using the correspondence table, the evaluation index can be set according to the design of the battery module 2.

[0045] In S5, the processing circuit 17 reads and executes the threshold comparison program 65 to compare the first evaluation index of the unit cell extracted in S4 with the first threshold A. For example, if the first evaluation index of the extracted unit cell is greater than the first threshold A (YES), the process proceeds to S6, and if it is equal to or less than the first threshold A (NO), the process proceeds to S10.

[0046] In S6, the processing circuit 17 reads and executes the second cell extraction program 66 to extract the unit cell (second unit cell) with the smallest first evaluation index from the results derived in S3. This is designated as cell Y, and the first evaluation index of cell Y is set to S y Let's say.

[0047] In S7, the processing circuit 17 reads and executes the second evaluation index derivation program 67 to calculate the second evaluation index (S x The method for deriving the second evaluation index is the same as the method for deriving the first evaluation index of S3.

[0048] Table 2 shows various values ​​for the single cells in the battery module 2 when deriving the second evaluation index.

[0049] [Table 2] In Table 2, like Table 1, there are 8 frames in the vertical direction i and 3 frames in the horizontal direction j, for a total of 24 frames. This table is regarded as a battery module, and each frame is regarded as a unit cell. In other words, 8 unit cells are arranged in the vertical direction i and 3 in the horizontal direction j, and 24 unit cells form one battery module. The values ​​in each frame are the positive electrode potential in Table 2(a), the temperature rise rate of the unit cell in Table 2(b), and the circled areas in Table 2(c) indicate the second evaluation index, while the other numbers indicate the first evaluation index. The numbers in the frame in Table 2(c) indicate the obtained value multiplied by 100. In Table 2, for example, if [i, j] is interchanged between cell X at [3, 2] and cell Y at [1, 3], the second evaluation index S is calculated as follows: x Since the value of the positive electrode potential depends on the single cell, the positive electrode potential v' in [3, 2] 32 The temperature rise rate depends on the position in the battery module, so the temperature rise rate t 13 takes 0.50. v' 32 , t 13 and C t= 1.0 and using equations 1, 2, and 3, the second evaluation index S x ' can be calculated as 0.0264.

[0050] The extraction of the unit cell and the derivation of the second evaluation index can be performed for multiple unit cells. As will be described in the second embodiment, the extraction of the unit cell and the derivation of the second evaluation index can be performed for all unit cells other than cell X, for example.

[0051] In S8, the processing circuit 17 reads and executes the first replacement determination program 68 to compare the second evaluation index of the unit cell derived in S7 with the second threshold value B. For example, if the second evaluation index of the extracted unit cell is smaller than the second threshold value B (YES), the process proceeds to S9A. If the second evaluation index is equal to or greater than the second threshold value B (NO), the process proceeds to S9B. The first threshold value A and the second threshold value B can be different values, and the second threshold value B can be a more limited value than the first threshold value A, for example, a value smaller than the first threshold value A. The first threshold value A and the second threshold value B may be the same value. Furthermore, the first threshold value A and the second threshold value B can be changed in response to environmental changes such as outside temperature.

[0052] In S9A, the processing circuit 17 reads and executes the notification program 69, thereby causing the user interface 20 to display a notification that the unit cell should be replaced with another unit cell in the battery module 2, for example.

[0053] In S9B, the processing circuit 17 reads and executes the notification program 69, thereby displaying on the user interface 20 a notification to replace the single cell, for example, with a single cell outside the battery module 2 or with a new single cell. Upon receiving instructions in S9A and S9B, the user interface 20 outputs a notification of single cell replacement via an output device.

[0054] (Second embodiment) As a modification of the first embodiment, a case where the unit cells to be replaced with cell X are all unit cells other than cell X will be described.

[0055] 3 is a block diagram showing a schematic modification of the battery system according to the embodiment. The first storage medium 6 includes a temperature measurement program for acquiring temperature from a temperature sensor. The battery control program 70 includes a potential calculation program 62A, a first temperature rise rate calculation program 62B, a first evaluation index derivation program 63, a first cell extraction program 64, a threshold comparison program 65, a third cell extraction program 72, a third evaluation index derivation program 73, a fourth evaluation index derivation program 74, a cell comparison program 75, a maximum evaluation index extraction program 77, and a second replacement determination program 78.

[0056] The flow of the battery diagnostic method according to the second embodiment will be described. Fig. 4 is an excerpt from a flowchart showing a modified example of the flow of the battery system according to the embodiment. Steps S1 to S5 and steps S9A and S9B onwards are the same as those in Fig. 2, so their description will be omitted. Here, steps S11 to S18, which exist between S5 and S9A and S9B, will be described.

[0057] In S11 and S16, the processing circuit 17 performs this loop from S11 to S16, and ends the loop when it has been performed for all unit cells other than cell X in the battery module 2.

[0058] In S12, the processing circuit 17 reads and executes the third cell extraction program 72 to extract, from all the unit cells derived in S3, a unit cell having a first evaluation index smaller than the first evaluation index of cell X. This extracted unit cell is designated as cell N, and the first evaluation index of cell N is designated as S n Let's say.

[0059] In S13, the processing circuit 17 reads and executes the third evaluation index derivation program 73 to calculate the second evaluation index (S x ') is derived.

[0060] In S14, the processing circuit 17 reads and executes the fourth evaluation index derivation program 74 to calculate the second evaluation index (S n Derive S n The method for deriving ' is S13's S x This is similar to the method for deriving '.

[0061] In S15, the processing circuit 17 reads and executes the cell comparison program 75 to calculate the second evaluation index S of the cell X, which was derived in S13 and S14. x ' and the second evaluation index S of cell N n The single cell with the larger second evaluation index is cell Y, and the second evaluation index of cell Y is S y Let's say.

[0062] In S17, the processing circuit 17 reads and executes the maximum evaluation index extraction program 77 to extract the unit cell with the largest second evaluation index among the cells Y. This is designated as cell Y', and the second evaluation index of cell Y' is S y 'Let's say.

[0063] In S18, the processing circuit 17 reads and executes the second replacement determination program 78 to compare the second evaluation index of the unit cell extracted in S17 with the second threshold value B. For example, if the second evaluation index of the extracted unit cell is smaller than the second threshold value B (YES), the process proceeds to S9A, and if it is equal to or larger than the second threshold value B (NO), the process proceeds to S9B.

[0064] (Third embodiment) As a modification of the first embodiment, a case where a temperature sensor is newly provided will be described.

[0065] 5 is a block diagram showing a schematic modification of the battery system according to the embodiment. The measurement unit 5 includes a temperature sensor 53 in addition to the configuration of the measurement unit 5 in FIG. 1. The battery measurement program 12 in the first storage medium 6 includes a temperature acquisition program 13 that acquires information about the temperature of the single cell 4. The battery control program 70 includes a second temperature increase rate calculation program 62C instead of the first temperature increase rate calculation program 62B of the battery control program 70 in FIG. 1. The temperature acquisition program 13 may be included in the battery measurement program 12 on the battery module 2 side, or may be included in the battery control program 70 on the information processing device 3 side.

[0066] The temperature sensor 53 is, for example, directly attached to the unit cell 4, and acquires the temperature of the unit cell 4. When information about temperature can be acquired directly using the temperature sensor 53, the temperature distribution corresponds to the rate of temperature increase.

[0067] The flow of the battery diagnostic method according to the third embodiment will be described. Fig. 6 is an excerpt from a flowchart showing a modified example of the flow of the battery system according to the embodiment. Steps S2A and S3 onwards are the same as those in Fig. 2, so their description will be omitted. Here, S12B and S12C will be described.

[0068] In S12B, the control circuit 7 reads and executes the temperature acquisition program 13, thereby using the temperature sensor 53 to acquire information about the temperature inside the single cell 4. The information about the temperature may be acquired directly using the temperature sensor 53, or may be acquired from a database or the like in which information about the temperature is stored.

[0069] In S12C, the processing circuit 17 reads and executes the second temperature rise rate calculation program 62C to calculate the temperature rise rate of the single cell 4. The temperature rise rate can be obtained, for example, by acquiring information about the temperature at time T1, then similarly acquiring information about the temperature at time T2, which is later than time T1, and calculating the temperature change per elapsed time. The time interval between time T1 and time T2 is preferably 120 milliseconds or longer, which is the interval that the temperature sensor 53 can detect. To obtain more accurate information, the temperature may be averaged. For example, the temperature is acquired at time T1, and then at time T1', which is later than time T1. The temperatures at T1 and T1' are averaged to obtain the temperature at T1. Next, the temperature is acquired at time T2, which is later than time T1', and similarly acquired at time T2', which is later than time T2. The temperatures at T2 and T2' are averaged to obtain the temperature at T2. In this case, it is desirable that the elapsed time between T1' and T2 is longer than the elapsed time between T1 and T1' or between T2 and T2'. This allows the temperature rise rate to be calculated with higher accuracy, with less influence of errors caused by temperature sensors and the like.

[0070] According to one or more of the embodiments and examples described above, there is provided an information processing device including a processing circuit that calculates a first evaluation index of a plurality of unit cells in a battery module and calculates a second evaluation index when a first unit cell in the battery module is swapped with a second unit cell in the battery module based on the first evaluation index, wherein the first evaluation index and the second evaluation index are calculated based on a positive electrode potential and a temperature rise rate. The information processing device according to the embodiment can provide an information processing device that can realize a long life of the battery module.

[0071] (Other embodiments) In this specification, the embodiments have been described using a lithium-ion secondary battery as an example of a unit cell. However, the type of unit cell is not limited to a lithium-ion secondary battery, such as a nickel-metal hydride battery. The battery module in each embodiment may be formed from three or more unit cells (single cells), or may be formed by electrically connecting a plurality of unit cells. When a battery module is formed from a plurality of unit cells, the plurality of unit cells may be electrically connected in series, or may be electrically connected in parallel. Furthermore, a secondary battery may have both a series connection structure in which a plurality of unit cells are connected in series, and a parallel connection structure in which a plurality of unit cells are connected in parallel. Furthermore, the battery module may be in the form of a battery string, a battery array, or the like, in which a plurality of battery modules are electrically connected. Furthermore, in a battery module in which a plurality of unit cells are electrically connected, each of the plurality of unit cells may be controlled individually, or some of the plurality of unit cells may be grouped and controlled separately.

[0072] Furthermore, the extraction of the unit cell with the highest first evaluation index may be performed for multiple unit cells. For example, unit cell A with the highest first evaluation index and unit cell B with the second highest first evaluation index are extracted. In this case, unit cell C with the lowest first evaluation index and unit cell D with the second lowest first evaluation index may be extracted, and the second evaluation index of unit cell A when unit cell A is swapped with unit cell C, and the second evaluation index of unit cell B when unit cell B is swapped with unit cell D may be calculated. This allows for more stable operation of the battery module.

[0073] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0074] The following describes the invention in terms of embodiments.

[0075] <1> determining a first evaluation index for a plurality of unit cells in the battery module; determining a second evaluation index when a first unit cell in the battery module is swapped with a second unit cell in the battery module based on the first evaluation index; processing circuitry; The first evaluation index and the second evaluation index are determined based on a positive electrode potential and a temperature rise rate. Information processing device.

[0076] <2> The first evaluation index and the second evaluation index can be determined using a function based on a product or weighted sum including values ​​of the positive electrode potential and the temperature rise rate, or a correspondence relationship between the positive electrode potential and the temperature rise rate. processing circuitry; <1> The information processing device described in

[0077] <3> When the first evaluation index is equal to or less than a first threshold, the second evaluation index can be obtained by exchanging the unit cell having the smallest first evaluation index with the unit cell having the largest first evaluation index. processing circuitry; <1> or <2> The information processing device described in

[0078] <4> When the second evaluation index is equal to or less than a second threshold, Notify the replacement of a single cell, processing circuitry; <1> from <3> 10. The information processing device according to claim 1,

[0079] <5> The positive electrode potential is calculated by analyzing a charge / discharge curve for each of the plurality of single cells. processing circuitry; <1> from <4> 10. The information processing device according to claim 1,

[0080] <6> the temperature rise rate is calculated based on a distance from each of the plurality of unit cells to a surface of the battery module and a thermal conductivity within the battery module. processing circuitry; <1> from <5> 10. The information processing device according to claim 1,

[0081] <7> The temperature rise rate is calculated based on information from a temperature sensor. processing circuitry; <1> from <6> 10. The information processing device according to claim 1,

[0082] <8> <1> from <7> an information processing device according to any one of the above items; a battery for which information is processed by the information processing device; Including, Battery system.

[0083] <9> a user interface that can output information related to the battery information processing and can input information related to the battery information processing; <8> The battery system described herein.

[0084] <10> The processing circuit determining a first evaluation index for a plurality of unit cells in the battery module; determining a second evaluation index when a first unit cell in the battery module is swapped with a second unit cell in the battery module based on the first evaluation index; It is a program, The first evaluation index and the second evaluation index are determined based on a positive electrode potential and a temperature rise rate. program.

[0085] <11> determining a first evaluation index of a plurality of unit cells in the battery module; determining a second evaluation index when a first unit cell in the battery module is swapped with a second unit cell in the battery module based on the first evaluation index; Including, The first evaluation index and the second evaluation index are determined based on a positive electrode potential and a temperature rise rate. Information processing methods. [Explanation of symbols]

[0086] 1 Battery System 2 Battery Module 3. Information processing equipment 4 single cells 5. Measurement Unit 6 First storage medium 7 Control Circuit 8 Charge / discharge circuit 9. First communication module 10 Power supply 11. First Data Management Program 12 Battery Measurement Program 13 Temperature acquisition program 17 Processing circuit 19 Second communication module 20 User Interface 51 Current measurement circuit 52 Voltage measurement circuit 53 Temperature Sensor 54 Timer 60 Second storage medium 61 Second Data Management Program 62A Potential Calculation Program 62B First temperature rise rate calculation program 62C Second temperature rise rate calculation program 63 First Evaluation Index Derivation Program 64 First Cell Extraction Program 65 Threshold Comparison Program 66 Second Cell Extraction Program 67 Second Evaluation Index Derivation Program 68 First Exchange Judgment Program 69 Notification Program 70 Battery Control Program 72 Third Cell Extraction Program 73 Third Evaluation Index Derivation Program 74 Fourth Evaluation Index Derivation Program 75 Cell Comparison Program 77 Maximum evaluation index extraction program 78 Second Exchange Judgment Program

Claims

1. determining a first evaluation index for a plurality of unit cells in the battery module; determining a second evaluation index when a first unit cell in the battery module is swapped with a second unit cell in the battery module based on the first evaluation index; a processing circuit; The first evaluation index and the second evaluation index are determined based on a positive electrode potential and a temperature rise rate. Information processing device.

2. The first evaluation index and the second evaluation index can be calculated using a function based on a product or a weighted sum including values ​​of the positive electrode potential and the temperature rise rate, or a correspondence relationship between the positive electrode potential and the temperature rise rate. processing circuitry; 2. The information processing device according to claim 1.

3. When the first evaluation index is equal to or less than a first threshold, the second evaluation index can be obtained by exchanging a unit cell having the smallest first evaluation index with a unit cell having the largest first evaluation index. processing circuitry; 2. The information processing device according to claim 1.

4. When the second evaluation index is equal to or less than a second threshold, Notify the replacement of a single cell, processing circuitry; 2. The information processing device according to claim 1.

5. The positive electrode potential is calculated by analyzing a charge / discharge curve for each of the plurality of single cells. processing circuitry; 2. The information processing device according to claim 1.

6. the temperature rise rate is calculated based on a distance from each of the plurality of unit cells to a surface of the battery module and a thermal conductivity within the battery module. processing circuitry; 2. The information processing device according to claim 1.

7. The temperature rise rate is calculated based on information from a temperature sensor. processing circuitry; 2. The information processing device according to claim 1.

8. An information processing device according to any one of claims 1 to 7; a battery for which information is processed by the information processing device; Including, Battery system.

9. a user interface that can output information related to the battery information processing and can input information related to the battery information processing; The battery system according to claim 8 .

10. The processing circuit determining a first evaluation index for a plurality of unit cells in the battery module; determining a second evaluation index when a first unit cell in the battery module is swapped with a second unit cell in the battery module based on the first evaluation index; It is a program, The first evaluation index and the second evaluation index are determined based on a positive electrode potential and a temperature rise rate. program.

11. determining a first evaluation index of a plurality of unit cells in the battery module; determining a second evaluation index when a first unit cell in the battery module and a second unit cell in the battery module are interchanged based on the first evaluation index; Including, The first evaluation index and the second evaluation index are determined based on a positive electrode potential and a temperature rise rate. Information processing methods.

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