Battery degradation amount calculation method, battery degradation amount calculation device, and computer program

Abstract

This method for calculating a storage battery degradation amount according to an embodiment comprises: acquiring usage conditions including time series information of the SOC and temperature of a storage battery cell; using a first function f pertaining to the SOC and temperature to calculate a first degradation coefficient of the storage battery cell used under the usage conditions; using history information of a second function g pertaining to the SOC and temperature to calculate a second degradation coefficient of the storage battery cell used under the usage conditions; calculating a corrected degradation coefficient obtained by correcting the first degradation coefficient with the second degradation coefficient; and using the corrected degradation coefficient to calculate the degradation amount of the storage battery cell used under the usage conditions.

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a storage battery degradation amount calculation method, a storage battery degradation amount calculation device, and a computer program. [Background technology]

[0002] In recent years, the market for storage batteries has expanded, and storage batteries are being installed in a variety of electronic devices. When users first consider which storage battery to install in their electronic devices, they must determine, for example, the battery's lifespan under the expected usage conditions.

[0003] For example, in order to consider how a storage battery will deteriorate when used in the environment that the user envisions, it was a time-consuming task for the user to obtain the necessary information, such as the characteristics of various storage batteries, and then consider the deterioration of the storage battery based on each individual characteristic. Furthermore, when users request a simulation from a battery manufacturer, they are required to disclose information about the product they are developing, making it difficult for users to easily obtain the information they need.

[0004] Given the above, there is a need for a service that allows users to easily compare how the deterioration of storage battery cells will progress in their usage environment based on information input by the user. To realize this service, a model that can predict the deterioration of storage battery cells with high accuracy was required. The degradation rate used in conventional technology is expressed, for example, in a matrix table corresponding to the SOC (state of charge) range of the storage battery cell being used (e.g., showing the degradation rate corresponding to the upper and lower usage limits of the SOC in a cycle test). The predicted value of the degradation amount is calculated using the degradation rate obtained from this matrix table. Creating the matrix table requires the acquisition of a large amount of data on the storage battery cell for each SOC range. Furthermore, when the SOC range in which the storage battery cell is used changes or the degradation rate changes as degradation progresses, the matrix table cannot represent these changes, making it difficult to improve the accuracy of degradation predictions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent No. 5852399 Summary of the Invention [Problem to be solved by the invention]

[0006] The embodiments of the present invention have been made in consideration of the above circumstances, and aim to provide a battery degradation amount calculation method, a battery degradation amount calculation device, and a computer program that calculate the degradation amount of a storage battery cell with high accuracy. [Means for solving the problem]

[0007] A method for calculating a deterioration amount of a storage battery according to an embodiment of the present invention acquires usage conditions including time-series information on the SOC and temperature of a storage battery cell, calculates a first deterioration coefficient of the storage battery cell used under the usage conditions using a first function related to the SOC and the temperature, calculates a second deterioration coefficient of the storage battery cell used under the usage conditions using history information of a second function related to the SOC and the temperature, calculates a corrected deterioration coefficient by correcting the first deterioration coefficient with the second deterioration coefficient, and calculates the deterioration amount of the storage battery cell used under the usage conditions using the corrected deterioration coefficient. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a storage battery deterioration calculation device according to an embodiment. [Figure 2] FIG. 2 is a diagram for explaining an example of a deterioration coefficient calculated by a deterioration coefficient calculation unit of the storage battery deterioration amount calculation device shown in FIG. [Figure 3] FIG. 3 is a diagram schematically showing an example of a change in deterioration coefficient before and after deterioration of a storage battery cell. [Figure 4]FIG. 4 is a diagram schematically illustrating an example of a change in the SOC of a storage battery cell and a change in the deterioration coefficient of the storage battery cell with use. [Figure 5] FIG. 5 is a flowchart illustrating an example of a method for calculating a deterioration amount of a storage battery according to an embodiment. [Figure 6] FIG. 6 is a diagram for explaining an example of the difference between the deterioration amount of a storage battery cell obtained by the method for calculating the deterioration amount of a storage battery according to one embodiment and the actual measurement value. [Figure 7] FIG. 7 is a diagram for explaining an example of the difference between the deterioration amount of a storage battery cell obtained by the storage battery deterioration amount calculation method of the comparative example and the actual measurement value. Embodiment

[0009] An embodiment of a storage battery deterioration amount calculation device, method, and computer program will be described in detail below with reference to the accompanying drawings. FIG. 1 is a diagram illustrating an example of the configuration of a storage battery deterioration calculation device according to an embodiment. The storage battery degradation calculation device 10 of this embodiment includes a communication circuit 1, an operation unit 2, a display unit 3, a memory 4, and a control circuit 5.

[0010] The communication circuit 1 inputs and outputs information between the storage battery deterioration amount calculation device 10 and an external device via a network. The operation unit 2 transmits operation information input by, for example, a user of the storage battery degradation level calculation device 10 to the control circuit 5. The operation unit 2 may include, for example, devices such as a mouse or a keyboard, or may include operation buttons or the like provided on the storage battery degradation level calculation device 10, or may include a detector such as a touch panel, camera, or microphone that detects the movement, behavior, or voice of the user.

[0011] The display unit 3 includes a display, such as a liquid crystal display or an organic EL display, that presents visual information to the user. The memory 4 includes, for example, a semiconductor storage device such as a RAM or a DRAM to which data can be written and read by the control circuit 5. The memory 4 stores programs executed by the control circuit 5. The memory 4 can also be used as an area for temporarily storing various data used when the control circuit 5 operates. The memory 4 can also temporarily store information input by a user. The memory 4 may also include an external storage device such as a hard disk connected to the outside of the storage battery degradation amount calculation device 10.

[0012] The control circuit 5 is a computing means including at least one processor such as a CPU (Central Processing Unit), and can realize the functions of multiple components included in the battery deterioration amount calculation device 10 by executing a program stored in the memory 4.

[0013] The control circuit 5 includes an acquisition unit 51, a display processing unit 52, a deterioration coefficient calculation unit 53, and a deterioration amount calculation unit . The acquisition unit 51 acquires information required for various calculations from the communication circuit 1, the operation unit 2, and the memory 4. The acquisition unit 51 can record the acquired information in the memory 4. The acquisition unit 51 acquires, for example, the usage conditions of the storage battery cell that are input by a user operating the operation unit 2 or that are supplied from the outside via the communication circuit 1. The usage conditions of the storage battery cell include, for example, time-series information on the SOC (state of charge) and temperature of the storage battery cell.

[0014] The display processing unit 52 uses information recorded in the memory 4, information acquired by the acquisition unit 51, and information supplied from the control circuit 5 to generate visual information to be presented to the user and output it to the display unit 23. The display processing unit 52 can generate, for example, numerical values ​​input by the user and numerical values ​​and graphs that visually show the results of calculations and simulations in the control circuit 5 as information that can be displayed by the display unit 23, and supply this to the display unit 23. The display processing unit 52 can also display, on the display unit 23, an area where the user can input numerical values ​​or characters, and input means such as buttons that the user can select, and can switch input by the input means between an active (selectable) state and an inactive (non-selectable) state.

[0015] The deterioration coefficient calculation unit 53 calculates the deterioration coefficient of the storage battery cell in the usage information input by the user. Note that the deterioration coefficient calculation unit 53 may acquire time-series information on the usage conditions as needed by simulating changes in the voltage, temperature, SOC, and current of the storage battery cell using a storage battery model based on the deterioration mechanism of the storage battery cell, for example, when the user inputs some of the usage conditions of the storage battery cell or the type of the storage battery cell.

[0016] The deterioration coefficient calculation unit 53 inputs the SOC and temperature of the storage battery cell at a predetermined time t into a first function f and a second function g related to the SOC and temperature of the storage battery cell, and calculates a deterioration coefficient C using the first deterioration coefficient and the second deterioration coefficient under the usage conditions specified by the user according to the following equation (1).

number

[0017] The first deterioration coefficient is a value obtained by inputting the SOC and temperature of the storage battery cell into the first function f. The second deterioration coefficient is the sum of 1 and a value (history information of the second function g) obtained by multiplying the value obtained by inputting the SOC and temperature T of the storage battery cell into the second function g by the current change amount Δi(i-(i-1)), over the usage time t of the storage battery cell. In other words, the history information of the second function g includes history information of the charge / discharge current value (e.g., current rate information) and time of the storage battery cell. In the above formula (1), the time t may be a value corresponding to the power-on time of the storage battery cell, a value corresponding to the number of cycles of the storage battery cell, or a value corresponding to the total capacity output by the storage battery cell (for example, the integrated value of the discharge current, the integrated value of the charge current, etc.).

[0018] FIG. 2 is a diagram for explaining an example of a deterioration coefficient calculated by a deterioration coefficient calculation unit of the storage battery deterioration amount calculation device shown in FIG. Here, an example of the first function f and the second function g in an arbitrary temperature environment (for example, 25° C.) is shown schematically.

[0019] The first function f is expressed, for example, as in the following formula (2), and includes the product of an exponential function of the temperature of the storage battery cell and an exponential function of the SOC of the storage battery cell. According to formula (2), the value of the first function f increases as the SOC of the storage battery cell increases. f(SOC, T)=D f ×exp(E f ×T)×exp(F f ×SOC) (2)

[0020] The second function g is expressed by, for example, the following formula (3), and includes the product of an exponential function of the temperature of the storage battery cell and an exponential function of the SOC of the storage battery cell. According to formula (3), the second function g is a value that decreases as the SOC of the storage battery cell increases. g(SOC, T)=D g ×exp(E g ×T)×exp(-F g ×SOC) (3)

[0021] In the above formulas (2) and (3), the coefficient D f , E f , F f , D g , E g , F g is a coefficient that is preset in the deterioration coefficient calculation unit 53 so that the actual measured value of the deterioration amount based on deterioration test data obtained by a deterioration test of the storage battery cell matches the calculated value of the deterioration amount calculated by the deterioration amount equations (4) and (5) described later. f, E f , F f , D g , E g , F g is stored in, for example, the memory 4. f , E f , F f , D g , E g , F g may be set for each temperature at which the battery cell is used. f , E f , F f , D g , E g , F g may be set for each type of storage battery cell. The deterioration coefficient calculation unit 53 calculates the coefficient D f , E f , F f , D g , E g , F g can also be updated.

[0022] 2 are merely examples and are not limited to these. The first function f may be, for example, an exponential expression of SOC as shown in the following formula (2-1) or a monomial expression of SOC as shown in the following formula (2-2). The first function f may also be a polynomial expression of SOC. f(SOC, T)=D f ×exp(-E f / T)×exp(F f ×SOC) (2-1) f(SOC, T)=D f ×exp(-E f / T)×(|F f -SOC|)^G f (2-2)

[0023] Similarly, the second function g may be, for example, an exponential expression of SOC as shown in the following formula (3-1) or a monomial expression of SOC as shown in the following formula (3-2). Also, the second function g may be a polynomial expression of SOC. g(SOC, T)=D g ×exp(-Eg / T)×exp(F g ×SOC) (3-1) g(SOC, T)=D g ×exp(-E g / T)×(|F g -SOC|)^G g (3-2)

[0024] Since the value calculated by the exponential formula converges, for example, if the second function g is an exponential formula, the increase in the deterioration coefficient C will be accelerated by the amount that the SOC passes through a low SOC or a high SOC due to the use of the storage battery cell. Also, for example, if the second function g is a polynomial formula, the increase in the deterioration coefficient C will be accelerated by the amount that the SOC passes through both a low SOC and a high SOC due to the use of the storage battery cell. The first function f and the second function g can be expressed as, for example, a coefficient D f , E f , F f , D g , E g , F g When setting the coefficients, a combination of a function and a coefficient that provides a calculated value that more closely matches the actually measured value may be used.

[0025] FIG. 3 is a diagram schematically showing an example of a change in deterioration coefficient before and after deterioration of a storage battery cell. Before the battery cell deteriorates (initial state), the time integral value of the second function g is zero, so the deterioration coefficient C is a value expressed by C = f(SOC, T) × 1. As the battery cell is subsequently used, the time integral value of the second function g gradually increases, and accordingly, the value of the deterioration coefficient C according to equation (1) also increases.

[0026] FIG. 4 is a diagram schematically illustrating an example of a change in the SOC of a storage battery cell and a change in the deterioration coefficient of the storage battery cell with use. This shows an example of how the deterioration coefficient C changes when the SOC of the battery cell is changed within a range of 10% to 90%. The deterioration coefficient C changes with the change in the SOC of the battery cell, and gradually increases over time. This is because the value of the second function g in the above formula (1) is integrated over time, and the longer the usage time, the larger the time integral value becomes.

[0027] The coefficient D of the second function g is set so that the value calculated by the second function g is 20 or less. g , E g , F g It is preferable to adjust the coefficient D of the second function g so that the value calculated by the second function g is 5 or less. g , E g , F g More preferably, the coefficient D of the second function g is adjusted so that the value calculated by the second function g is 2 or less. g , E g , F g It is recommended to adjust the following.

[0028] By setting the range of values ​​of the second function g as above, the coefficient D f , E f , F f and coefficient D g , E g , F g This makes it easier to adjust the degradation coefficient C, and also makes it possible to prevent a rapid increase in the degradation coefficient C. The second function g is a correction term that corrects the value calculated by the first function f over time, and by adjusting the first function f when the second function g exceeds the above range, the degradation coefficient C can be adjusted to match the actual measured value.

[0029] The deterioration amount calculation unit 54 calculates the deterioration amount of the storage battery cell using the deterioration coefficient C calculated by the deterioration coefficient calculation unit 53. The deterioration amount of the storage battery cell includes a capacity maintenance rate y1 and a resistance increase rate y2. For each of the capacity maintenance rate y1 and the resistance increase rate y2 calculated by the deterioration amount calculation unit 54, the coefficient D used in calculating the deterioration coefficient C is f , Ef , F f , D g , E g , F g In this case, the deterioration coefficient used to calculate the capacity maintenance rate y1 and the deterioration coefficient used to calculate the resistance increase rate y2 may be different values, but in the following description, the deterioration coefficient will be represented by the same symbol C in the formula for calculating the capacity maintenance rate and the formula for calculating the resistance increase rate.

[0030] The capacity maintenance rate y1 of the storage battery cell is a value indicating the ratio of the capacity at time t to the initial capacity of the storage battery cell, and is expressed by, for example, the following formula (4): (t-1) By subtracting the deterioration amount C(T,SOC,t)*dt in unit time Δt(t-(t-1)) from t The initial value of the capacity maintenance rate y1 is 100%, and as the deterioration of the storage battery cell progresses, the capacity maintenance rate decreases. y1 t =y1 (t-1) -C(T,SOC,t)*dt (4)

[0031] The resistance increase rate y2 of the battery cell is a value indicating the rate at which the internal resistance value at time t has increased relative to the internal resistance value in the initial state of the battery cell, and is expressed by, for example, the following formula (5): (t-1) By adding the increase amount C(T,SOC,t)*dt in unit time Δt(t-(t-1)) to the resistance increase rate y2 at time t, t The initial value of the resistance increase rate y2 is 0%, and as the deterioration of the storage battery cell progresses, the resistance increase rate increases. y2 t =y2 (t-1) +C(T,SOC,t)*dt (5) The deterioration amount calculation unit outputs the capacity maintenance rate and the resistance increase rate as the deterioration amount.

[0032] Next, an example of a method for calculating the deterioration amount of a storage battery according to this embodiment will be described. FIG. 5 is a flowchart illustrating an example of a method for calculating a deterioration amount of a storage battery according to an embodiment. Prior to calculating the deterioration amount of the storage battery, the deterioration coefficient calculation unit 53 acquires deterioration test data and preliminarily calculates a coefficient D so that the deterioration amount calculated by the equations (4) and (5) coincides with the deterioration amount obtained by the deterioration test. f , E f , F f , D g , E g , F g The degradation coefficient calculation unit 53 sets the set coefficient D f , E f , F f , D g , E g , F g The value is recorded in memory 4.

[0033] The deterioration coefficient calculation unit 53 acquires the usage conditions (temperature, SOC, time) of the storage battery cell (step S1). Note that the deterioration coefficient calculation unit 53 may use a model of the storage battery cell to simulate the SOC, temperature, and time of the storage battery cell based on the usage conditions specified by the user, and acquire these values.

[0034] Next, the deterioration coefficient calculation unit 53 calculates a first deterioration coefficient using the first function f and a second deterioration coefficient using the second function g using the acquired information on the SOC, temperature, and time of the storage battery cell (step S2).

[0035] Next, the deterioration coefficient calculation unit 53 uses the calculated first deterioration coefficient and second deterioration coefficient to calculate a deterioration coefficient C at time t (a value obtained by correcting the first deterioration coefficient with the second deterioration coefficient) according to the above-mentioned formula (1) (step S3). The deterioration coefficient calculation unit 53 outputs the calculated deterioration coefficient C (corrected deterioration coefficient) to the deterioration amount calculation unit 54.

[0036] The deterioration amount calculation unit 54 uses the deterioration coefficient C to calculate the deterioration amount of the storage battery cell per unit time Δt (step S4). Next, the deterioration amount calculation unit 54 calculates the previous values ​​(y1 (t-1) , y2 (t-1)) to the deterioration of the battery cell in unit time Δt, and calculate the deterioration of the battery cell at time t (y1 t , y2 t ) (step S5), and outputs the calculated deterioration amount (step S6). In the above process, the deterioration amount calculation unit 54 calculates the previous values ​​(y1 (t-1) , y2 (t-1) ) is read out from the memory 4, and the calculated deterioration amounts y1 and y2 are recorded in the memory 4 in association with the time information (or a value corresponding to the time information).

[0037] The value of the deterioration amount output from the deterioration amount calculation unit 54 is recorded in the memory 4, for example, and is also processed by the display processing unit 52 as information that can be viewed by the user and is supplied to the display unit 3 and the communication circuit 1.

[0038] Next, an example of the effect of the storage battery deterioration amount calculation method of this embodiment will be described. FIG. 6 is a diagram for explaining an example of the difference between the deterioration amount of a storage battery cell obtained by the method for calculating the deterioration amount of a storage battery according to one embodiment and the actual measurement value. FIG. 7 is a diagram for explaining an example of the difference between the deterioration amount of a storage battery cell obtained by the storage battery deterioration amount calculation method of the comparative example and the actual measurement value.

[0039] The method for calculating the deterioration amount of a storage battery in the comparative example differs from the above-described embodiment in that the deterioration amount is calculated using the deterioration coefficient of the storage battery cell as a constant value. Here, the storage battery cell is used under four different temperature environments: 25°C, 45°C, 55°C, and 65°C. The storage battery cell is used under the following conditions: a charge / discharge current of 1C in a range of 0% to 100% SOC; a charge / discharge current of 1C in a range of 0% to 90% SOC; a charge / discharge current of 3C in a range of 0% to 100% SOC; a charge / discharge current of 3C in a range of 0% to 90% SOC; and a charge / discharge current of 3C in a range of 20% to 80% SOC. Examples of the error (sum of squares of the difference between the calculated value and the actual measured value) are shown for the amount of deterioration of the storage battery cell calculated using the methods of the above-described embodiment and comparative example, between the calculated value and the actual measured value obtained by a deterioration test.

[0040] A comparison between the calculated values ​​of the deterioration amount obtained by the comparative example storage battery deterioration amount calculation method and the actual measured values ​​showed that there were cases where the error value was significantly large depending on the usage conditions of the storage battery cell. In contrast, a comparison of the calculated values ​​of the deterioration amount using the battery deterioration amount calculation method of this embodiment with the actual measured values ​​shows that the error is not significantly large under any of the usage conditions of the battery cell, and that this embodiment is able to calculate calculated values ​​that are in line with the actual measured values.

[0041] As described above, according to the present embodiment, it is possible to provide a storage battery degradation amount calculation method, a storage battery degradation amount calculation device, and a computer program that calculate the degradation amount of a storage battery cell with high accuracy. As a result, according to the battery degradation amount calculation device, the battery degradation amount calculation method, and the computer program of this embodiment, a user can easily test how the degradation of a battery cell progresses by inputting the SOC and temperature environment of the battery cell, and can select, from among various battery cells, a battery cell that will achieve the best operation under the expected usage conditions.

[0042] The first function f and the second function g are merely examples and are not limited to those described in the above embodiment. For example, when the characteristics cause deterioration of the storage battery cell due to use at a low SOC, the first function f becomes a function that decreases as the SOC increases. When the characteristics cause deterioration of the storage battery cell due to use at both a low SOC and a high SOC, the first function f becomes a function that increases in value in the low SOC range and the high SOC range. Furthermore, the first function f may be a function that becomes maximum or minimum at a specific SOC, or a first function f with characteristics that vary depending on the temperature of the usage environment may be used. Furthermore, the second function g is a function for correcting the degradation rate based on the usage history of the SOC of the storage battery cell, and is not limited to a function that decreases as the SOC of the storage battery cell increases. For example, if degradation is accelerated at a high SOC due to the usage environment of the storage battery cell, the second function g may be a function that increases as the SOC increases, or may be a function that becomes maximum or minimum at a specific SOC, or a second function g with characteristics that vary depending on the temperature of the usage environment may be used.

[0043] The program according to this embodiment may be transferred in a state where it is stored in an electronic device, or in a state where it is not stored in an electronic device. In the latter case, the program may be transferred via a network, or in a state where it is stored in a storage medium. The storage medium is a non-transitory tangible medium. The storage medium is a computer-readable medium. The storage medium may be in any form, such as a CD-ROM or a memory card, as long as it is capable of storing the program and is computer-readable.

[0044] 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 intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims.

[0045] [Appendix 1] Obtaining usage conditions including time-series information on the SOC and temperature of the storage battery cell; calculating a first deterioration coefficient of the storage battery cell used under the usage conditions using a first function relating to SOC and temperature; calculating a second deterioration coefficient of the storage battery cell used under the usage conditions using history information of a second function related to SOC and temperature; Calculating a corrected deterioration coefficient by correcting the first deterioration coefficient with the second deterioration coefficient; a storage battery deterioration amount calculation method for calculating the deterioration amount of the storage battery cell used under the usage conditions using the corrected deterioration coefficient. [Appendix 2] The method for calculating the deterioration amount of a storage battery according to [Appendix 1], wherein the first function is a function that increases as the SOC increases, and the second function is a function that decreases as the SOC increases. [Appendix 3] The battery deterioration amount calculation method according to [Appendix 1] or [Appendix 2], wherein the history information of the second function includes history information of a value calculated by inputting the SOC and temperature of the battery cell under the usage conditions into the second function and a charge / discharge current value of the battery cell. [Appendix 4] The battery deterioration amount calculation method according to any one of [Appendix 1] to [Appendix 3], wherein the second function includes a product of an exponential function of the temperature of the storage battery cell and an exponential function of the SOC of the storage battery cell. [Appendix 5] The battery deterioration amount calculation method according to any one of [Appendix 1] to [Appendix 4], wherein the first function includes a product of an exponential function of the temperature of the storage battery cell and an exponential function of the SOC of the storage battery cell. [Appendix 6] an acquisition unit that acquires usage conditions including the SOC and temperature of the storage battery cell; a deterioration coefficient calculation unit that calculates a first deterioration coefficient of the storage battery cell used under the usage conditions by using a first function related to SOC and temperature, calculates a second deterioration coefficient of the storage battery cell used under the usage conditions by using history information of a second function related to SOC and temperature, and calculates a corrected deterioration coefficient by correcting the first deterioration coefficient with the second deterioration coefficient; a deterioration amount calculation unit that calculates the deterioration amount of the storage battery cell used under the usage conditions using the corrected deterioration coefficient. [Appendix 7] A computer program that causes a computer to execute the storage battery deterioration amount calculation method described in any one of [Appendix 1] to [Appendix 5].

Claims

1. Acquire usage conditions including time-series information on the SOC and temperature of the storage battery cell; calculating a first deterioration coefficient of the storage battery cell used under the usage conditions using a first function relating to SOC and temperature; calculating a second deterioration coefficient of the storage battery cell used under the usage conditions using history information of a second function related to SOC and temperature; calculating a corrected deterioration coefficient by correcting the first deterioration coefficient with the second deterioration coefficient; a storage battery deterioration amount calculation method for calculating the deterioration amount of the storage battery cell used under the usage conditions using the corrected deterioration coefficient.

2. 2. The method for calculating the deterioration amount of a storage battery according to claim 1, wherein the first function increases as the SOC increases, and the second function decreases as the SOC increases.

3. 2. The battery deterioration amount calculation method according to claim 1, wherein the history information of the second function includes history information of a value calculated by inputting an SOC and a temperature of the storage battery cell under the usage conditions into the second function and a charge / discharge current value of the storage battery cell.

4. The method for calculating the deterioration amount of the battery according to claim 1 , wherein the second function includes a product of an exponential function of the temperature of the battery cell and an exponential function of the SOC of the battery cell.

5. The method for calculating the deterioration amount of the battery according to claim 1 , wherein the first function includes a product of an exponential function of the temperature of the battery cell and an exponential function of the SOC of the battery cell.

6. an acquisition unit that acquires usage conditions including an SOC and a temperature of the storage battery cell; a deterioration coefficient calculation unit that calculates a first deterioration coefficient of the storage battery cell used under the usage conditions by using a first function related to SOC and temperature, calculates a second deterioration coefficient of the storage battery cell used under the usage conditions by using history information of a second function related to SOC and temperature, and calculates a corrected deterioration coefficient by correcting the first deterioration coefficient with the second deterioration coefficient; a degradation amount calculation unit that calculates a degradation amount of the storage battery cell used under the usage conditions using the corrected degradation coefficient.

7. A computer program that causes a computer to execute the method for calculating the deterioration level of a storage battery according to claim 1.

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