Power supply device, diagnostic device and diagnostic method

Abstract

A power supply device according to one aspect of the present technology is provided with: a secondary battery; an electric circuit for charging or discharging the secondary battery; and a measurement unit for measuring a voltage and a current of the secondary battery. This power supply device is further provided with a calculation unit and a derivation unit. The calculation unit calculates a plurality of deterioration parameters of the secondary battery on the basis of the measurement values obtained by the measurement unit. The derivation unit derives a repurpose target of the secondary battery on the basis of the plurality of deterioration parameters obtained through calculation by the calculation unit and deterioration rates of the plurality of deterioration parameters set for each repurpose target candidates.

Description

[Technical Field]

[0001] The present technology relates to a power supply device, a diagnostic device, and a diagnostic method. [Background technology]

[0002] As the use of lithium-ion secondary batteries expands, the depletion of natural resources such as lithium and cobalt, which are the raw materials for these batteries, is becoming a problem. One way to solve this problem is to repeatedly reuse lithium-ion secondary batteries until the end of their product life. For efficient secondary use, it is important to properly understand the deterioration state of the battery at the end of its primary use and to carry out secondary use appropriate to that state.

[0003] Patent Document 1 describes a method for determining whether a lithium-ion secondary battery is suitable for secondary use. When a battery after primary use is diagnosed using the method described in Patent Document 1, the following degradation parameters can be obtained: positive electrode capacity retention rate, negative electrode capacity retention rate, and battery capacity deviation. These parameters can then be used to appropriately determine whether the lithium-ion secondary battery is suitable for secondary use.

[0004] Patent Document 2 describes a control device that can change settings to match the secondary use destination when the primary use destination and secondary use destination are different. By using the control device described in Patent Document 2, when a lithium-ion battery is connected to a secondary use destination, input / output information related to power between the secondary use destination and the new use destination can be obtained, and a control method appropriate for this can be used. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-258337 [Patent Document 2] Japanese Patent Publication No. 2020-161422 Summary of the Invention

[0006] However, the method described in Patent Document 1 only determines whether secondary reuse is possible, and does not provide specific recommendations for secondary reuse. Therefore, it is difficult to select an appropriate secondary reuse destination without advanced specialized knowledge of the positive electrode capacity retention rate, negative electrode capacity retention rate, and the meaning of the battery's capacity deviation, as well as an understanding of the internal state of the battery after changes in these parameter values.

[0007] Furthermore, when the control device described in Patent Document 2 is used, parameters are automatically optimized after the secondary battery is connected to a secondary usage destination. However, there is a problem in that it is difficult to obtain sufficient effects from optimization unless an appropriate secondary usage destination is selected from among the many secondary usage destinations.

[0008] Therefore, it is desirable to provide a power supply device, a diagnostic device, and a diagnostic method that can appropriately determine the deterioration state of a secondary battery at the end of primary use, and that can also present secondary use destinations that will result in higher efficiency through optimization.

[0009] A power supply device according to a first aspect of the present technology includes a secondary battery, an electric circuit for charging or discharging the secondary battery, and a measurement unit for measuring the voltage and current of the secondary battery. The power supply device further includes a calculation unit and a derivation unit. The calculation unit calculates multiple deterioration parameters of the secondary battery based on the measured values ​​obtained by the measurement unit. The derivation unit derives secondary uses of the secondary battery based on the multiple deterioration parameters calculated by the calculation unit and the deterioration rates of the multiple deterioration parameters set for each secondary use candidate.

[0010] A diagnostic device according to a second aspect of the present technology includes a calculation unit and a derivation unit. The calculation unit calculates a plurality of deterioration parameters of the secondary battery based on measured values ​​of the voltage and current of the secondary battery. The derivation unit derives secondary uses of the secondary battery based on the plurality of deterioration parameters calculated by the calculation unit and the deterioration rates of the plurality of deterioration parameters set for each secondary use candidate.

[0011] The diagnostic method according to the third aspect of the present technology includes the following two methods. (A) calculating a plurality of deterioration parameters of the secondary battery based on measured values ​​of the voltage and current of the secondary battery; (B) Deriving a secondary use of the secondary battery based on the plurality of deterioration parameters obtained by the calculation and the deterioration rates of the plurality of deterioration parameters set for each secondary use candidate.

[0012] In a power supply device according to a first aspect of the present technology, a diagnostic device according to a second aspect of the present technology, and a diagnostic method according to a third aspect of the present technology, multiple degradation parameters of a secondary battery are calculated based on measured values ​​of the secondary battery's voltage and current. Then, a secondary use of the secondary battery is derived based on the multiple degradation parameters obtained by the calculation and the degradation rates of multiple degradation parameters set for each secondary use candidate. This makes it possible to avoid presenting secondary uses in which only a specific degradation parameter quickly reaches a maximum degradation value, making the secondary battery unusable, and instead present secondary uses in which the secondary battery can be used for as long as possible. In this way, the present technology can appropriately determine the degradation state of a secondary battery at the end of primary use and further present secondary uses that will achieve a high degree of efficiency through optimization.

[0013] Note that the effects of the present technology are not necessarily limited to the effects described here, but may be any of a series of effects related to the present technology described below. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating an example of functional blocks of a power supply device according to a first embodiment of the present technology. [Figure 2] FIG. 2 is a diagram illustrating an application example of the power supply device of FIG. [Figure 3] Figure 3(A) shows an example of the distribution of five degradation parameters after the primary use. Figure 3(B) shows an example of the distribution of five degradation parameters after the secondary use. [Figure 4] FIG. 4 is a diagram showing an example of the relationship between the square root of the usage time and the positive electrode capacity deterioration. [Figure 5] FIG. 5 is a diagram showing a procedure for presenting secondary usage destinations in the power supply device of FIG. [Figure 6] FIG. 6 is a diagram illustrating an example of functional blocks of a power supply system including a server device according to a second embodiment of the present technology. [Figure 7] FIG. 7 is a diagram illustrating an application example of the power supply system of FIG. [Figure 8] FIG. 8 is a diagram illustrating an example of functional blocks of a charging / discharging device according to a third embodiment of the present technology. [Figure 9] FIG. 9 is a diagram illustrating an example of functional blocks of a power supply system including a server device according to a fourth embodiment of the present technology. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present technology will be described in detail with reference to the drawings. The description will be made in the following order. 1. First embodiment Example of deriving and presenting secondary usage destinations for power supply equipment (Figures 1 to 5) 2. Second embodiment In a server device connected to a power supply unit via a network Examples of deriving secondary uses (Figures 6 and 7) 3. Third embodiment Example of deriving and presenting secondary usage destinations for charging / discharging devices (Figure 8) 4. Fourth Embodiment In a server device connected to a charging / discharging device via a network Example of deriving secondary usage destinations (Figure 9) 5. Modifications common to all embodiments

[0016] <1. First embodiment> [composition] The configuration of a power supply device 100 according to a first embodiment of the present technology will be described. The power supply device 100 is a device that supplies power using a secondary battery 110 mounted thereon, and is a standalone device that does not have the function of communicating with external devices. The power supply device 100 can be used, for example, as an uninterruptible power supply. For example, as shown in FIG. 2, the power supply device 100 can be mounted on a vehicle 1000 such as an electric car. Note that the power supply device 100 can also be mounted on, for example, a forklift, an electric two-wheeler, an electric kick scooter, etc.

[0017] The power supply device 100 has not only the function of supplying power but also the function of presenting a secondary use destination of the secondary battery 110 (power supply device 100). "Secondary use destination" refers to a new use destination of the used secondary battery 110 (power supply device 100). The power supply device 100 includes a secondary battery 110, for example, as shown in FIG. 1.

[0018] The secondary battery 110 is a lithium-ion secondary battery. The lithium-ion secondary battery included in the secondary battery 110 may be a unit cell, a battery block in which a plurality of unit cells are connected, or an assembled battery in which a battery block and accessories are integrally packed. In an assembled battery, a plurality of lithium-ion secondary batteries are connected in series. The assembled battery may also include a plurality of lithium-ion secondary batteries electrically connected in parallel.

[0019] The secondary battery 110 can be used for the following purposes (1) to (4), for example. (1) Applications where rapid discharge is rare (2) Applications where there are few opportunities for rapid power reception (3) Uses where the battery is left in a fully charged or fully discharged state for a short period of time (4) Applications where the device is not exposed to low temperatures for long periods of time

[0020] (Uses where rapid discharge is rare) The decrease in positive electrode active material is often the result of a large overvoltage at the interface between the positive electrode active material and the electrolyte during primary use. The situation where a large overvoltage is applied to the interface between the positive electrode active material and the electrolyte is more pronounced when lithium ions are pushed into the positive electrode active material than when lithium ions are extracted from the positive electrode active material. The situation where lithium ions are pushed into the positive electrode active material occurs when discharging a lithium-ion secondary battery. Therefore, rapid discharge of a lithium-ion secondary battery whose positive electrode capacity has decreased during primary use is likely to further accelerate the decrease in positive electrode capacity and shorten the life of the lithium-ion secondary battery. Therefore, when the positive electrode capacity has decreased, the secondary use of the battery is preferably for applications with few opportunities for rapid discharge, specifically, electric vehicles, smartphones, tablets, laptops, etc.

[0021] (Uses where rapid power reception is rare) The decrease in negative electrode active material is often the result of a large overvoltage applied to the interface between the negative electrode active material and the electrolyte during primary use. The situation in which a large overvoltage is applied to the interface between the negative electrode active material and the electrolyte is more pronounced when lithium ions are pushed into the negative electrode active material than when lithium ions are extracted from the negative electrode active material. The situation in which lithium ions are pushed into the negative electrode active material occurs when a lithium-ion secondary battery is charged. Therefore, rapid charging of a lithium-ion secondary battery whose negative electrode capacity has decreased during primary use is likely to further accelerate the decrease in negative electrode capacity and shorten the life of the lithium-ion secondary battery. Therefore, when the negative electrode capacity has decreased, the secondary use of the battery is preferably in applications that rarely require rapid charging, specifically, UPS (uninterruptible power supply), vacuum cleaners, drones, etc.

[0022] (Uses where the time spent in a fully charged or fully discharged state is short) Deterioration of the positive or negative electrode balance of a battery is often the result of the positive or negative electrode being kept at a potential close to the electrochemical window for a long period of time during primary use. This potential close to the electrochemical window occurs when the lithium-ion secondary battery is left in a fully charged or fully discharged state. Therefore, if a lithium-ion secondary battery with deteriorated positive or negative electrode balance during primary use is left in a fully charged or fully discharged state for a long period of time, the positive or negative electrode is exposed to a potential close to the electrochemical window, which is likely to further accelerate the deterioration of the positive or negative electrode balance. Therefore, when the positive or negative electrode balance is deteriorated, the secondary use of the battery is preferably for applications that do not require long periods of time in a fully charged or fully discharged state, such as energy storage systems (ESS) and electric vehicles.

[0023] (Uses where the time spent in a low temperature environment is short) The main cause of the increase in the impedance component of a battery is the charge / discharge cycle, and the longer the battery is used, the greater the impedance component. This increase in impedance component has a strong temperature dependency, and the lower the temperature, the greater the impedance component. The larger the impedance component of a battery, the smaller the actual charge / discharge capacity. Therefore, it is desirable for lithium-ion secondary batteries with an increased impedance component to be used in a state with as low an impedance value as possible, i.e., in a room temperature to warm environment. Therefore, when the impedance component is increased, the preferred secondary use is one that does not require the battery to be exposed to a low-temperature environment for long periods of time, such as an energy storage system (ESS).

[0024] Next, the deterioration parameters used to determine the secondary usage destination will be described.

[0025] In this embodiment, the deterioration parameter is the positive electrode capacity deterioration d α , negative electrode capacity deterioration d β , Positive electrode balance deterioration d γ , negative electrode balance deterioration d δ and impedance degradation dε A method called OCV (Open Circuit Voltage) analysis is used to derive the five-dimensional degradation vector d (equation (1) below) consisting of these degradation parameters.

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[0026] OCV analysis is the analysis of the OCP (Open Circuit Potential) curve function φ for each of the positive and negative electrodes. p (x p ),φ n (x n ) are individually stretched and translated, the difference between the two is calculated, and the resulting function (Equation (2) below) is used to approximate the charge / discharge curve data (Equation (3) below) obtained by measurement.

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[0027] where S p is the positive polar translation, Q p is the positive electrode capacity, S n is the negative pole translation, Q n is the negative electrode capacity, and R0 is the impedance. In the OCV analysis, the electrical characteristics (S p ,Q p ,S n ,Q n , R0) is determined.

[0028] (Positive electrode capacity deterioration d α ) Positive electrode capacity degradation d α is the positive electrode capacity Q obtained by OCV analysis p The positive electrode capacity of the secondary battery 110 in the initial state (i.e., a new secondary battery 110 that has not deteriorated) is expressed as Qp,0 In this case, the positive electrode capacity degradation d α is calculated by the following equation (4): The secondary battery 110 in the initial state corresponds to a specific example of a "reference secondary battery" of the present technology.

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[0029] In the initial state of the secondary battery 110, d α = 0, and the positive electrode capacity Q p As the value of d decreases, the capacity of the positive electrode decreases. α increases. Positive electrode capacity Q p When decreases to half of the initial value, d α = 1. In this specification, this state is called the most degraded state.

[0030] Maximum degradation state (d α =1) does not correspond to the minimum positive electrode capacity that satisfies the required specifications of the device in which the secondary battery 110 is installed, but corresponds to the positive electrode capacity beyond which it is deemed that the safety of the secondary battery 110 cannot be guaranteed at the material level. This is because the objective of this technology is to reduce the environmental load by "using up the secondary battery 110 at the material level without waste." Note that the maximum degradation states of other degradation parameters described below are also defined based on the same concept.

[0031] (Negative electrode capacity deterioration d β ) Negative electrode capacity deterioration d β is the negative electrode capacity Q obtained by OCV analysis n The negative electrode capacity of the secondary battery 110 in the initial state is Q n,0 In this case, the negative electrode capacity deterioration d β is calculated using the following equation (5).

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[0032] In the initial state of the secondary battery 110, d β= 0, and the negative electrode capacity Q n As the negative electrode capacity decreases, d β increases. Negative electrode capacity Q n When decreases to half of the initial value, d β = 1. In this specification, this state is called the most degraded state.

[0033] (Positive electrode balance deterioration d γ ) Positive electrode balance deterioration γ is the positive electrode translation S obtained by OCV analysis p The deterioration parameter is derived from the positive electrode balance deterioration d γ is calculated using the following equation (6).

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[0034] In the initial state of the secondary battery 110, d γ = 0, and the positive polar translation S p As the absolute value of d increases, the positive electrode balance deterioration γ The positive pole parallel movement S p The absolute value of the positive electrode capacity Q p,0 When the value increases to 25% of γ = 1. In this specification, this state is called the most degraded state.

[0035] (Anode balance deterioration d δ ) Deterioration of negative electrode balance δ is the negative electrode translation S obtained by OCV analysis n The deterioration parameter is derived from the negative electrode balance deterioration d δ is calculated using the following equation (7).

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[0036] In the initial state of the secondary battery 110, d δ = 0, and the negative pole translation S n As the absolute value of d increases, the negative electrode balance deteriorationδ rises. Negative pole parallel movement S n The absolute value of the negative electrode capacity Q n,0 When the value increases to 25% of δ = 1. In this specification, this state is called the most degraded state.

[0037] (Impedance degradation d ε ) Impedance degradation d ε is a deterioration parameter derived from the impedance R0 obtained by OCV analysis. The impedance of the secondary battery 110 in the initial state is R 0,0 When this is the case, the impedance degradation d ε is calculated using the following equation (8).

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[0038] In the initial state of the secondary battery 110, d ε = 0, and as the impedance R0 increases, the impedance degradation d ε When the impedance R0 increases to +50% of the initial value, d ε = 1. In this specification, this state is called the most degraded state.

[0039] Next, a method for determining a secondary usage destination will be described.

[0040] This technology is based on the premise that the secondary battery 110 is not used for only one purpose and reaches the end of its lifespan, but rather that the secondary battery 110 is reused to reach the end of its lifespan. In this technology, the purpose of secondary reuse is to reduce the environmental load by "using the secondary battery 110 at the material level without waste," and secondary reuse of the secondary battery 110 is presented with the aim of making all degradation parameters 1 when the secondary battery 110 is disposed of.

[0041] Figure 3(A) shows an example of the deterioration vector d of the secondary battery 110 when used for a first purpose. Figure 3(B) shows an example of the deterioration vector d of the secondary battery when used for a second purpose (secondary use). In Figure 3(B), the deterioration vector d of the secondary battery 110 when used for the first purpose is superimposed on the deterioration vector d of the secondary battery when used for the second purpose (secondary use).

[0042] In Figure 3(A), the negative electrode balance deterioration d δ has already reached 1. Therefore, the secondary battery 110 must be discarded even though the other degradation parameters have not yet reached 1. Therefore, for a secondary battery 110 having such a degradation vector d, usable materials still remain, and it can be said that material is being wasted.

[0043] On the other hand, in FIG. 3(B), the deterioration parameters of the secondary battery 110 when used for the second use (secondary use) are approximately 1. This is because the secondary battery 110 was used at a secondary use where the deterioration parameters of the secondary battery 110 are approximately 1. In this technology, a secondary use where material waste is unlikely to occur is presented based on the deterioration vector d of the secondary battery 110 when used for the first use and a preset deterioration rate vector v. The deterioration rate vector v is calculated based on the positive electrode capacity deterioration rate v α , negative electrode capacity deterioration rate v β , the rate of deterioration of the positive electrode balance v γ , negative electrode balance deterioration rate v δ and the impedance degradation rate v ε The method for presenting secondary usage destinations is explained in detail below.

[0044] The deterioration rate vector v1 of the secondary battery 110 used in the first application is the positive electrode capacity deterioration rate v 1,α , negative electrode capacity deterioration rate v 1,β , the rate of deterioration of the positive electrode balance v 1,γ , negative electrode balance deterioration rate v 1,δ and the impedance degradation rate v 1,εIt is expressed as a five-dimensional vector (Equation (9)) consisting of

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[0045] The deterioration rate vector v2 of the secondary battery 110 used for the second use (secondary use) is the positive electrode capacity deterioration rate v 2,α , negative electrode capacity deterioration rate v 2,β , the rate of deterioration of the positive electrode balance v 2,γ , negative electrode balance deterioration rate v 2,δ and the impedance degradation rate v 2,ε It is expressed as a five-dimensional vector (Equation (10)) consisting of

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[0046] FIG. 4 shows the relationship between the square root of the usage time t of the secondary battery 110 and the positive electrode capacity deterioration d α In Figure 4, t1 is the usage time for the first purpose. 2、α is the usage time for the second purpose (secondary use). 1,α is the deterioration of the positive electrode capacity in the first application. 1,α is the rate of deterioration of the positive electrode capacity in the first application. 2,α is the rate of deterioration of the positive electrode capacity in the second use (secondary use).

[0047] In this technology, as one of the techniques for presenting secondary usage destinations using a simple algorithm, it is assumed that each degradation parameter increases in proportion to the square root of the usage time of the secondary battery 110. This assumption follows a "root law" that is empirically known to hold true for the degradation of secondary batteries. Because it is assumed that the degradation of secondary batteries follows the root law, the degree of degradation of the secondary battery 110 increases linearly with the square root of the usage time t, for example, as shown in FIG. 4.

[0048] Usage time for the second purpose (secondary use) t 2、αis expressed by the following equation (11).

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[0049] By the way, the deterioration of the battery is the positive electrode capacity deterioration d α The five degradation parameters do not progress only at the time of use, but progress independently. If one degradation parameter reaches 1 before the other degradation parameters, the battery must be discontinued at that point. Therefore, the usage time t 2、α However, this does not necessarily mean that the actual usable time for the second use (secondary use) will be the same. To know the actual usable time for the second use (secondary use), it is necessary to know which of the five degradation parameters will reach 1 the earliest, and to know the time at which that degradation parameter will reach 1.

[0050] Therefore, first, equation (11) is expressed as a general equation as shown in equation (12).

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[0051] For the second use (secondary use), the actual available time (usage time t2) is t 2,ξ and is expressed by the following equations (13) and (14).

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[0052] In order for all degradation parameters to be 1 when the secondary use is completed, the usage time t 2,ξ Therefore, in this technology, it is sufficient that the usage time t 2,ξThe secondary use destination is selected based on the degree of match between the above. Specific criteria for the selection include, for example, the following formula (15), formula (16), and formula (17).

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[0053] According to equation (15), the usage time t 2,ξ The deterioration rate vector v2 is selected so that the difference between the maximum and minimum values ​​of is the smallest. As a result, it is possible to select the use corresponding to the deterioration rate vector v2 selected by equation (15). According to equation (16), the use time t 2,ξ The deterioration rate vector v2 that minimizes the variance of is selected. As a result, it becomes possible to select the application corresponding to the deterioration rate vector v2 selected in equation (16).

[0054] (Configuration of power supply device 100) Next, the configuration of the power supply device 100 will be described.

[0055] The power supply device 100 includes, for example, as shown in FIG. 1, a secondary battery 110, a charge / discharge circuit 120, an IV measurement circuit 130, an OCV analysis unit 140, a deterioration vector calculation unit 150, a deterioration rate library 160, a repurpose derivation unit 170, and a display unit 180.

[0056] The secondary battery 110 includes a lithium-ion secondary battery. The lithium-ion secondary battery included in the secondary battery 110 may be a unit cell, a battery block in which a plurality of unit cells are connected, or an assembled battery in which the battery block and accessories are integrally packed. In an assembled battery, a plurality of lithium-ion secondary batteries are connected in series. The assembled battery may also include a plurality of lithium-ion secondary batteries electrically connected in parallel.

[0057] The charge / discharge circuit 120 has a charge circuit that charges the secondary battery 110 and a discharge circuit that discharges the secondary battery 110. The charge circuit includes, for example, a generator and a converter, and controls the voltage for charging the secondary battery 110. The IV measurement circuit 130 includes a measurement circuit that measures the current and voltage of the secondary battery 110. The IV measurement circuit 130 outputs the current value obtained by measurement in the measurement circuit and the voltage value obtained by measurement in the measurement circuit to the OCV analysis unit 140.

[0058] The OCV analysis unit 140 performs OCV analysis based on the measured values ​​(current value and voltage value) obtained by the IV measurement circuit 130. The OCV analysis unit 140 uses, for example, the above-mentioned formula (2) to approximate the charge / discharge curve data (the above-mentioned formula (3)) obtained by measurement by the IV measurement circuit 130. As a result, the OCV analysis unit 140 calculates the electrical characteristics (S p ,Q p ,S n ,Q n ,R0) is derived.

[0059] The deterioration vector calculation unit 150 calculates the electrical characteristics (S p ,Q p ,S n ,Q n , R0) and the electrical characteristics (Q p,0 ,Q n,0 ,R 0,0 ) and calculates five deterioration parameters (deterioration vector d) of the secondary battery 110. The deterioration vector calculation unit 150 calculates the deterioration vector d using, for example, the above-mentioned equations (4) to (8).

[0060] The deterioration rate library 160 includes a nonvolatile memory. The deterioration rate library 160 stores a deterioration rate vector v set for each secondary usage candidate. The deterioration rate vector v is, for example, data obtained from a secondary battery 110 prepared as a master. The deterioration rate vector v can be obtained, for example, by solving the following equation (18) using a deterioration vector d at the time of use time t1 for the first use.

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[0061] The repurposed battery derivation unit 170 derives a secondary-use destination for the secondary battery 110 based on the deterioration vector d calculated by the deterioration vector calculation unit 150 and the deterioration rate vector v set for each secondary-use destination candidate read from the deterioration rate library 160. The repurposed battery derivation unit 170 selects the optimal secondary-use destination using, for example, the above-mentioned formula (15) or formula (16).

[0062] The repurposed battery derivation unit 170 generates a video signal including information about the derived secondary use of the secondary battery 110, and outputs the video signal to the display unit 180. The display unit 180 displays the secondary use of the secondary battery 110 based on the video signal input from the repurposed battery derivation unit 170.

[0063] [Operation] Next, the operation of the power supply device 100 will be described.

[0064] 5 shows the procedure for presenting secondary usage destinations in the power supply device 100. First, the charge / discharge circuit 120 fully discharges the secondary battery 110 (step S101). Next, the charge / discharge circuit 120 starts charging the secondary battery 110 (step S102). Next, the IV measurement circuit 130 measures the current and voltage of the secondary battery 110 during charging (step S103). After the charge / discharge circuit 120 has fully charged the secondary battery 110 (step S104), it starts discharging the secondary battery 110 (step S105). Next, the IV measurement circuit 130 measures the current and voltage of the secondary battery 110 during discharging (step S106).

[0065] Next, the OCV analysis unit 140 performs OCV analysis based on the measurement values ​​obtained from the IV measurement circuit 130 during charging and discharging (step S107). The OCV analysis unit 140 generates charge / discharge curve data using, for example, the measurement values ​​obtained from the IV measurement circuit 130 during charging and discharging, and approximates the generated charge / discharge curve data using the above-mentioned formula (2). As a result, the OCV analysis unit 140 calculates the electrical characteristics (S p ,Q p ,S n ,Q n ,R0) is derived.

[0066] Next, the degradation vector calculation unit 150 calculates the electrical characteristics (S p ,Q p ,S n ,Q n , R0) and the electrical characteristics (Q p,0 ,Q n,0 ,R 0,0) (step S108). The repurposed destination derivation unit 170 derives a secondary usage of the secondary battery 110 based on the deterioration vector d calculated by the deterioration vector calculation unit 150 and the deterioration rate vector v set for each secondary usage candidate read from the deterioration rate library 160 (step S109). The display unit 180 displays the secondary usage derived by the repurposed destination derivation unit 170 (step S110). In this way, the secondary usage of the secondary battery 110 is presented.

[0067] [effect] Next, the effects of the power supply device 100 will be described.

[0068] In this embodiment, multiple deterioration parameters (deterioration vector d) of the secondary battery 110 are calculated based on measured values ​​of the voltage and current of the secondary battery 110. Then, a secondary use of the secondary battery 110 is derived based on the multiple deterioration parameters (deterioration vector d) obtained by the calculation and the deterioration rates (deterioration rate vector v) of the multiple deterioration parameters set for each secondary use candidate. This makes it possible to avoid presenting secondary uses in which only a specific deterioration parameter quickly reaches a maximum deterioration state value, making the secondary battery 110 unusable, and to present secondary uses that can use the secondary battery 110 for as long as possible. In this way, this embodiment can appropriately determine the deterioration state of the secondary battery at the time primary use ends, and further make it possible to present secondary uses that will increase the degree of efficiency through optimization.

[0069] In this embodiment, the electrical characteristics (S p ,Q p ,S n ,Q n , R0) and the electrical characteristics (Q p,0 ,Q n,0 ,R 0,0) are used to calculate a plurality of deterioration parameters (deterioration vector d) of the secondary battery 110. This makes it possible to grasp the deterioration state of the secondary battery 110 from multiple perspectives, and to effectively select a secondary utilization destination that will achieve a high degree of efficiency through optimization.

[0070] Furthermore, in this embodiment, the secondary usage destination is displayed on the display unit 180. This allows the user to easily understand the secondary usage destination.

[0071] 2. Second embodiment A power supply system including a server device 300 as a diagnostic device according to a second embodiment of the present technology will be described. Fig. 6 shows an example of functional blocks of the power supply system. For example, as shown in Fig. 6, the power supply system includes a power supply device 200 and a server device 300. The power supply device 200 and the server device 300 are capable of communicating with each other via a communication network 400. The communication network 400 is configured to include, for example, the Internet, a cloud network, or a network specific to a business operator.

[0072] The power supply device 200 is a device that supplies power using a secondary battery 110 installed therein, and is a network communication type device that has the function of communicating with external devices. The power supply device 200 can be used, for example, as an uninterruptible power supply. The power supply device 200 can also be used, for example, as a battery backup device. The power supply device 200 can be installed, for example, in a vehicle 2000 such as an electric vehicle, as shown in FIG. 7.

[0073] 6, the power supply device 200 includes a secondary battery 110, a charge / discharge circuit 120, an IV measurement circuit 130, a display unit 180, and a communication unit 210. The communication unit 210 is a communication interface that communicates with the server device 300 via a communication network 400. The IV measurement circuit 130 outputs measurement values ​​(current values ​​and voltage values) obtained by measurement to the server device 300 via the communication unit 210. The display unit 180 displays secondary usage destinations acquired from the server device 300 via the communication unit 210.

[0074] When power supply device 200 is mounted on vehicle 2000, for example, display unit 180 within power supply device 200 may be omitted, and terminal device 500 having the functions of display unit 180 may be connected to communication network 400. In this case, terminal device 500 displays the secondary usage destinations acquired from server device 300.

[0075] 6, the server device 300 includes a communication unit 310, a control unit 320, and a deterioration rate library 160. The communication unit 310 is a communication interface that communicates with the power supply device 200 via a communication network 400. The control unit 320 includes, for example, a central processing unit (CPU). The control unit 320 executes the functions of, for example, an OCV analysis unit 140, a deterioration vector calculation unit 150, a repurpose derivation unit 170, and a refinement unit 321.

[0076] The refiner 321 updates the degradation rate vector v stored in the degradation rate library 160 using the degradation vector d obtained by the degradation vector calculator 150. The refiner 321 may update the degradation rate vector v using, for example, an exponential moving average method as shown in the following equation (19). In equation (19), the parameter x is determined based on the variation in the value of d / √t1. Empirically, the parameter x is set to a value generally greater than 0 and smaller than 0.1.

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[0077] In this embodiment, the deterioration vector d and the deterioration rate vector v are calculated in the server device 300. Even in this case, it is possible to obtain the same effects as in the above-described embodiment. Furthermore, with this configuration, for example, one server device 300 can be shared by multiple power supply devices 200, thereby reducing the cost of each power supply device 200.

[0078] 3. Third Embodiment A power supply system including a charge / discharge device 700 having a function as a diagnostic device according to a third embodiment of the present technology will be described. FIG. 8 illustrates an example of a functional block of the power supply system. For example, as shown in FIG. 8, the power supply system includes a secondary battery pack 600 and the charge / discharge device 700. The secondary battery pack 600 and the charge / discharge device 700 are electrically connected via an electrical connection circuit.

[0079] The secondary battery pack 600 is a portable battery pack and includes a secondary battery 110, for example, as shown in Fig. 8. The secondary battery pack 600 is, for example, a battery pack for a power tool, a battery pack for an electrically assisted bicycle, or a battery pack for an electric kick scooter. The charge / discharge device 700 includes, for example, a charge / discharge circuit 120, an IV measurement circuit 130, an OCV analysis unit 140, a deterioration vector calculation unit 150, a deterioration rate library 160, and a repurpose derivation unit 170, as shown in Fig. 8.

[0080] In this embodiment, the secondary battery 110 is provided in a secondary battery pack 600 that is provided separately from the charge / discharge device 700 having the charge / discharge circuit 120 and the like. Even in this case, the same effects as those of the above-described embodiment can be obtained. Furthermore, with this configuration, it is possible to present secondary use destinations for portable battery packs as well.

[0081] 4. Fourth Embodiment A power supply system including a server device 300 as a diagnostic device according to a fourth embodiment of the present technology will be described. Fig. 9 illustrates an example of functional blocks of the power supply system. For example, as shown in Fig. 9, the power supply system includes a secondary battery pack 600, a charging / discharging device 800, and a server device 300. The charging / discharging device 800 and the server device 300 are capable of communicating with each other via a communication network 400. For example, as shown in Fig. 9, the charging / discharging device 800 includes a charging / discharging circuit 120, an IV measuring circuit 130, a display unit 180, and a communication unit 210.

[0082] In this embodiment, the secondary battery 110 is provided in a secondary battery pack 600 that is provided separately from the charge / discharge device 800 that has the charge / discharge circuit 120 and the like. Even in this case, the same effects as those of the above-described embodiment can be obtained. Furthermore, with this configuration, it is possible to present secondary use destinations for portable battery packs as well.

[0083] In the present embodiment, the deterioration vector d and the deterioration rate vector v are calculated by the server device 300. Even in this case, the same effects as those of the above-described embodiment can be obtained. Furthermore, with this configuration, for example, one server device 300 can be shared by a plurality of charging / discharging devices 800, thereby reducing the cost of each charging / discharging device 800.

[0084] <5. Modifications common to all embodiments> In each of the above embodiments, the deterioration vector calculation unit 150 calculates the positive electrode capacity deterioration d α , negative electrode capacity deterioration d β , Positive electrode balance deterioration d γ , negative electrode balance deterioration d δ and impedance degradation d ε At this time, the repurpose lead-out unit 170 may calculate at least two of the negative electrode capacity deterioration d β , Positive electrode balance deterioration d γ , negative electrode balance deterioration d δand impedance degradation d ε A deterioration vector d consisting of at least two of the above is used to derive a secondary use of the secondary battery 110. Even in this case, depending on the purpose of secondary use, it is possible to present a secondary use that will have a high degree of efficiency due to optimization.

[0085] The present technology can also be configured as follows. <1> A secondary battery; an electric circuit for charging or discharging the secondary battery; a measurement unit for measuring the voltage and current of the secondary battery; a calculation unit that calculates a plurality of deterioration parameters of the secondary battery based on the measurement values ​​obtained by the measurement unit; a derivation unit that derives a secondary-use destination of the secondary battery based on the plurality of deterioration parameters calculated by the calculation unit and the deterioration rates of the plurality of deterioration parameters set for each secondary-use destination candidate; Equipped with power supply. <2> The calculation unit performs an OCV (Open Circuit Voltage) analysis based on the measurement values ​​obtained by the measurement unit, and calculates a plurality of deterioration parameters of the secondary battery based on the electrical characteristics of the secondary battery obtained thereby and the electrical characteristics of a reference secondary battery. <1> The power supply device according to claim 1. <3> The plurality of deterioration parameters include at least two of positive electrode capacity deterioration, negative electrode capacity deterioration, positive electrode balance deterioration, negative electrode balance deterioration, and impedance deterioration. <2> The power supply device according to claim 1. <4> The electrical characteristics include a positive electrode capacity when the plurality of degradation parameters includes the positive electrode capacity degradation, a negative electrode capacity when the plurality of degradation parameters includes the negative electrode capacity degradation, a positive electrode translation and the positive electrode capacity when the plurality of degradation parameters includes the positive electrode balance degradation, a negative electrode translation and the negative electrode capacity when the plurality of degradation parameters includes the negative electrode balance degradation, and an impedance when the plurality of degradation parameters includes the impedance degradation. <3> The power supply device according to claim 1. <5> The information processing device further includes a display unit that displays information about the secondary use destination obtained by the derivation unit. <1> Or <4> 10. The power supply device according to claim 9, wherein: <6> a calculation unit that calculates a plurality of deterioration parameters of the secondary battery based on measured values ​​of the voltage and current of the secondary battery; a derivation unit that derives a secondary-use destination of the secondary battery based on the plurality of deterioration parameters calculated by the calculation unit and the deterioration rates of the plurality of deterioration parameters set for each secondary-use destination candidate; Equipped with Diagnostic equipment. <7> calculating a plurality of deterioration parameters of the secondary battery based on measured values ​​of voltage and current of the secondary battery; Deriving a secondary use of the secondary battery based on the plurality of deterioration parameters obtained by the calculation and the deterioration rates of the plurality of deterioration parameters set for each secondary use candidate. Contains Diagnostic methods.

Claims

1. A secondary battery; an electric circuit for charging or discharging the secondary battery; a measurement unit for measuring the voltage and current of the secondary battery; a calculation unit that calculates a plurality of deterioration parameters of the secondary battery based on the measurement values ​​obtained by the measurement unit; a derivation unit that derives a secondary-use destination of the secondary battery based on the plurality of deterioration parameters calculated by the calculation unit and the deterioration rates of the plurality of deterioration parameters set for each secondary-use destination candidate; Equipped with power supply.

2. The calculation unit performs an OCV (Open Circuit Voltage) analysis based on the measured values ​​obtained by the measurement unit, and calculates a plurality of deterioration parameters of the secondary battery based on the electrical characteristics of the secondary battery obtained thereby and the electrical characteristics of a reference secondary battery. The power supply device of claim 1 .

3. The plurality of deterioration parameters include at least two of positive electrode capacity deterioration, negative electrode capacity deterioration, positive electrode balance deterioration, negative electrode balance deterioration, and impedance deterioration. The power supply device according to claim 2 .

4. The electrical characteristics include a positive electrode capacity when the plurality of degradation parameters includes the positive electrode capacity degradation, a negative electrode capacity when the plurality of degradation parameters includes the negative electrode capacity degradation, a positive electrode translation and the positive electrode capacity when the plurality of degradation parameters includes the positive electrode balance degradation, a negative electrode translation and the negative electrode capacity when the plurality of degradation parameters includes the negative electrode balance degradation, and an impedance when the plurality of degradation parameters includes the impedance degradation. The power supply device according to claim 3.

5. The information processing device further includes a display unit that displays information about the secondary use destination obtained by the derivation unit. The power supply device of claim 1 .

6. a calculation unit that calculates a plurality of deterioration parameters of the secondary battery based on measured values ​​of the voltage and current of the secondary battery; a derivation unit that derives a secondary-use destination of the secondary battery based on the plurality of deterioration parameters calculated by the calculation unit and the deterioration rates of the plurality of deterioration parameters set for each secondary-use destination candidate; Equipped with Diagnostic equipment.

7. calculating a plurality of deterioration parameters of the secondary battery based on measured values ​​of voltage and current of the secondary battery; Deriving a secondary use of the secondary battery based on the plurality of deterioration parameters obtained by the calculation and the deterioration rates of the plurality of deterioration parameters set for each secondary use candidate. Contains Diagnostic methods.

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