Battery determination method

Abstract

A battery determination method includes: a determination step of determining a state X defined by a state of charge or a voltage; a first adjustment step of adjusting a battery in the state X to a state Y by at least one of charging and discharging the battery; a first measurement step of measuring a battery resistance value in the state Y as a first resistance value; a second adjustment step of adjusting the battery in the state Y again by charging and discharging the battery in accordance with (i) or (ii), (i) in a case where the state Y is adjusted from a high SOC side or a high voltage side in the first adjustment step, the state Y is adjusted again by sequentially performing discharging and charging, (ii) in a case where the state Y is adjusted from a low SOC side or a low voltage side in the first adjustment step, the state Y is adjusted again by sequentially performing charging and discharging; a second measurement step of measuring a battery resistance value in the state Y as a second resistance value; and a determination step of determining whether the battery is a normal product based on the first resistance value and the second resistance value.

Description

Technical Field

[0001] This disclosure relates to a method for determining batteries. Background Technology

[0002] Regarding batteries, there are known techniques for distinguishing between batteries manufactured by legitimate manufacturers (hereinafter referred to as legitimate products), batteries that imitate legitimate products, and batteries that improperly modify legitimate products (hereinafter referred to as non-legitimate products). For example, Patent Document 1 discloses a battery pack equipped with a control unit that determines a battery to be non-legitimate if the absolute value of the difference in battery weight is greater than a preset threshold.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-174487 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] While patent document 1, for example, uses the difference in battery weight to determine whether a product is counterfeit, it is desirable to be able to determine counterfeit products even when there is no difference in battery weight. This disclosure was made in view of the above-mentioned realities, and its main objective is to provide a method for determining whether a battery is counterfeit without relying on its weight.

[0008] Technical solutions for solving the problem

[0009] A method for determining whether a battery is a genuine product includes: a determination step, determining a state X defined by a state of charge (SOC) or voltage as the battery state; a first adjustment step, adjusting the battery state X to state Y by charging and discharging at least one of the following: a first measurement step, measuring the resistance value of the battery under state Y after adjustment by the first adjustment step as a first resistance value; and a second adjustment step, adjusting the battery state after the first measurement step to state Y again by charging and discharging according to either (i) or (ii) the following: (i) in the first adjustment step... (ii) In the process of adjusting from the high SOC side or the high voltage side to the above state Y, by performing discharge and charge sequentially, the state Y is adjusted again from the low SOC side or the low voltage side; (ii) In the process of adjusting from the low SOC side or the low voltage side to the above state Y in the first adjustment process, by performing charge and discharge sequentially, the state Y is adjusted again from the high SOC side or the high voltage side; (iii) In the second measurement process, the resistance value of the battery under the above state Y after adjustment by the second adjustment process is measured as the second resistance value; and (iv) In the determination process, based on the first resistance value and the second resistance value, it is determined whether the battery is a genuine product.

[0010] According to the determination method described in [1], the above-mentioned state X and state Y are defined by the above-mentioned state of charge (SOC).

[0011] According to the determination method described in [1], the above-mentioned state X and state Y are determined by the above-mentioned voltage.

[0012] According to any one of the determination methods in [1] to [3], in the first adjustment step described above, at least one of the charging and discharging is performed with a current value of 1 / 3C or higher.

[0013] According to any one of the determination methods in [1] to [4], in the second adjustment step described above, the charging and discharging are performed with a current value of 1 / 3C or higher.

[0014] According to any one of the determination methods in [1] to [5], in the second adjustment step described above, the above-described charging and discharging are performed in accordance with (i) above.

[0015] According to any one of the determination methods in [1] to [5], in the second adjustment step described above, the above-described charging and discharging that conform to (ii) are performed.

[0016] Invention Effects

[0017] In this disclosure, the ability to identify counterfeit products without relying on the weight of the battery is achieved. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the battery determination method in this disclosure.

[0019] Figure 2 This is a diagram illustrating the mechanism in this disclosure.

[0020] Figure 3 This is a diagram illustrating an example of the first adjustment step in this disclosure.

[0021] Figure 4 This is a diagram illustrating an example of the first adjustment step in this disclosure.

[0022] Figure 5 This is a diagram illustrating an example of the first adjustment step in this disclosure.

[0023] Figure 6 This is a diagram illustrating the second adjustment process in this disclosure.

[0024] Figure 7 This is a diagram illustrating the determination process in this disclosure. Detailed Implementation

[0025] The method for determining the battery in this disclosure will be explained in detail below.

[0026] Figure 1This is a flowchart illustrating the battery determination method of the present disclosure. In the battery determination method of the present disclosure, firstly, a state X defined by the state of charge (SOC) or voltage is determined as the state of the battery (determination step, S1). Next, the battery in state X is subjected to at least one of charging and discharging to adjust the state of the battery to state Y (first adjustment step, S2). Next, the resistance value of the battery in state Y after adjustment by the first adjustment step is measured as a first resistance value (first measurement step, S3). Next, the battery after the first measurement step is subjected to charging and discharging that meets the following (i) or (ii) to adjust the state of the battery back to state Y (second adjustment step, S4). (i) In the case that the battery was adjusted to state Y from the high SOC side or the high voltage side in the first adjustment step, the battery was adjusted to state Y again from the low SOC side or the low voltage side by sequentially performing discharging and charging. (ii) If the battery is adjusted to state Y from a low SOC side or a low voltage side in the first adjustment step described above, it is adjusted back to state Y from a high SOC side or a high voltage side by sequentially performing charging and discharging. Next, the resistance value of the battery in state Y after adjustment in the second adjustment step is measured as a second resistance value (second measurement step, S5). Then, based on the first resistance value and the second resistance value, it is determined whether the battery is a genuine product (determination step, S6).

[0027] According to this disclosure, the battery is determined to be a genuine product or a non-genuine product based on the resistance value after adjusting from the high SOC side or the high voltage side to state Y (resistance value after discharge) and the resistance value after adjusting from the low SOC side or the low voltage side to state Y (resistance value after charging). Therefore, non-genuine products can be identified without relying on the weight of the battery.

[0028] The mechanism of the determination method in this disclosure is explained using the accompanying drawings. Figure 2 This is a diagram illustrating the mechanism in this disclosure. Specifically, Figure 2 (a) is a diagram showing the movement of ions (charge carrier ions) when further charging is performed after charging to a predetermined state of charge (SOC). Figure 2 (b) is a graph showing the movement of ions (charge carrier ions) after being discharged to a predetermined SOC and then recharged. Figure 2 As shown in (a), when the battery is charged, the charging reaction begins to proceed from the negative electrode composite layer (negative electrode active material) on the electrolyte layer side. Therefore, if charging is further performed after reaching a predetermined SOC, the charge carrier ions need to react with the negative electrode active material on the negative electrode current collector side, and the distance the charge carrier ions travel becomes longer. As a result, the charging resistance increases relatively. Additionally, as... Figure 2As shown in (b), when the battery is discharged, the discharge reaction begins to proceed from the negative electrode composite layer (negative electrode active material) on the electrolyte layer side. Therefore, when charging is performed after discharging to a predetermined SOC, the charge carrier ions can react with the negative electrode active material on the electrolyte layer side, resulting in a shorter migration distance for the charge carrier ions and a relatively smaller charging resistance. Furthermore, when discharging is performed after charging to a predetermined SOC, the discharge resistance is relatively smaller, while when further discharging is performed after discharging to a predetermined SOC, the discharge resistance is relatively larger.

[0029] Thus, during battery charging and discharging, because the active materials located on the electrolyte layer side are preferentially used in the charging and discharging reaction, the concentration of charge carrier ions in the electrode layers (positive electrode composite layer and negative electrode composite layer) sometimes becomes uneven. Additionally, as... Figure 2 As shown in (a) and (b), even batteries adjusted to the same SOC will exhibit differences in resistance (both charging and discharging resistances) due to variations in their past experiences—specifically, whether they were charging or discharging immediately prior to the current charge. Furthermore, the resistance differences caused by such uneven ion concentration are influenced by the materials, thicknesses, and capacity ratios of the negative and positive electrode composite layers. Therefore, by comparing the resistance differences with those of a genuine battery, it is possible to determine whether the battery in question is a genuine or non-genuine product.

[0030] 1. Determine the process steps

[0031] The determining step in this disclosure is the step of determining a state X, defined by the state of charge (SOC) or voltage, as the state of the battery. There are no particular limitations on the method for determining state X; methods using devices such as ammeters and voltmeters can be cited.

[0032] Based on the determined results, it is possible to determine how to adjust the battery to state Y through charge / discharge control in the first adjustment step described later. For example, if the state of charge (SOC) or voltage of state X is lower than that of state Y, it is possible to determine that charging will adjust the battery to state Y in the first adjustment step. Alternatively, if the SOC or voltage is lower than that of state Y, it is possible to determine that discharging after charging will adjust the battery to state Y in the first adjustment step. Furthermore, if the SOC or voltage of state X is higher than that of state Y, it is possible to determine that discharging will adjust the battery to state Y in the first adjustment step. Also, if the SOC or voltage is higher than that of state Y, it is possible to determine that charging after discharging will adjust the battery to state Y in the first adjustment step.

[0033] 2. First adjustment process

[0034] The first adjustment step in this disclosure is a step of adjusting the state of the battery to state Y by charging and discharging the battery in state X. When state X is a state defined by SOC (State of Charge), state Y is also a state defined by SOC. Similarly, when state X is a state defined by voltage, state Y is also a state defined by voltage.

[0035] When state Y is defined by the battery's state of charge (SOC), state Y (SOC) is typically less than 100%. State Y (SOC) can be, for example, 20% or more, or 30% or more, or even 50% or more. On the other hand, state Y (SOC) can be, for example, 90% or less, or even 70% or less.

[0036] On the other hand, when state Y is defined by the battery voltage, state Y (voltage) is not particularly limited. Here, state Y (voltage) is set to V. Y Set the voltage of the battery when fully charged to V. M In the case of V Y Typically less than V M V Y / V M For example, it could be 0.2 or higher, or 0.3 or higher, or even 0.5 or higher. On the other hand, V... Y / V M For example, it can be below 0.9, or it can be below 0.7.

[0037] State Y can be preset or set based on state X determined by the above-described determination process. For example, if state X is the same as the preset state Y (e.g., if the state of charge (SOC) of state X is the same as that of state Y), state Y can be set to a state with a different SOC than state X.

[0038] In the first adjustment process, the charging and discharging current values ​​are, for example, 1 / 5C or more, or 1 / 4C or more, or 1 / 3C or more. On the other hand, the charging and discharging current values ​​are, for example, 1C or less, or 2 / 3C or less.

[0039] Here, the charging and discharging process in the first adjustment step will be explained, assuming that the state of the battery is specified by the SOC.

[0040] Figure 3 This is a diagram illustrating an example of the first adjustment step in this disclosure. Specifically, Figure 3 (a) is a diagram illustrating the first adjustment process when state X has a higher SOC than state Y, and the first resistance value is measured as the resistance value after discharge. Additionally, Figure 3 (b) is a diagram illustrating the first adjustment process when state X has a higher SOC than state Y, and the first resistance value is measured as the resistance value after charging. For example, Figure 3 As shown in (a), state Y can be adjusted by simply discharging. Therefore, the first resistance value, described later, can be measured as the resistance value after discharge. On the other hand, as... Figure 3 As shown in (b), both discharging and charging can be performed to adjust to state Y. For example, discharging from state X to state P1, where state P1 has a lower SOC than state Y, and then charging from state P1 to state Y. Thus, the first resistance value described later can be measured as the resistance value after charging. Furthermore, it is preferable, for example, that the SOC of state P1 is 5% or more lower than that of state Y.

[0041] Figure 4 This is a diagram illustrating an example of the first adjustment step in this disclosure. Specifically, Figure 4 (a) is a diagram illustrating the first adjustment process when state X is the same as state Y, and the first resistance value is measured as the resistance value after discharge. Additionally, Figure 4 (b) is a diagram illustrating the first adjustment process when state X is the same as state Y, and the first resistance value is measured as the resistance value after charging. When state X is the same as state Y, as... Figure 4 As shown in (a) and (b), in the first adjustment step, it is preferable to adjust to state Y by performing both charging and discharging. For example, Figure 4 As shown in (a), for example, the circuit is charged to state Q1, where the State of Charge (SOC) is higher than that of state X (state Y), and then discharged from state Q1 to state Y. Therefore, the first resistance value, described later, can be measured as the resistance value after discharge. Furthermore, it is preferable, for example, that the SOC of state Q1 is 5% or more higher than that of state Y. On the other hand, as... Figure 4 As shown in (b), for example, the circuit is discharged to state P1, which is a state where the SOC is lower than that of state X (state Y), and then charged from state P1 to state Y. Therefore, the first resistance value, described later, can be measured as the resistance value after charging. State P1 is the state described above.

[0042] Figure 5 This is a diagram illustrating an example of the first adjustment step in this disclosure. Specifically, Figure 5 (a) is a diagram illustrating the first adjustment process when state X has a lower SOC than state Y, and the first resistance value is measured as the resistance value after charging. Additionally, Figure 5(b) is a diagram illustrating the first adjustment process when state X has a lower SOC than state Y, and the first resistance value is measured as the resistance value after discharge. Figure 5 As shown in (a), it is possible to adjust to state Y by charging only. Therefore, the first resistance value, described later, can be used as the resistance value after charging for measurement. On the other hand, as... Figure 5 As shown in (b), both discharging and charging can be performed to adjust to state Y. For example, charging from state X to state Q1, where state Q1 has a higher SOC than state Y, and then discharging from state Q1 to state Y. Thus, the first resistance value described later can be used as the resistance value after discharge for measurement. Furthermore, state Q1 is the state described above.

[0043] 3. First measurement procedure

[0044] The first measurement step in this disclosure is to measure the resistance value of the battery under state Y after adjustment by the first adjustment step described above, as a first resistance value. The first resistance value can be a charging resistance value or a discharging resistance value. There are no particular limitations on the method for measuring the first resistance value; for example, the IV method can be cited.

[0045] 4. Second adjustment process

[0046] The second adjustment step in this disclosure is a step of charging and discharging the battery after the first measurement step in accordance with either (i) or (ii) below, and adjusting the state of the battery back to the state Y described above.

[0047] (i) In the case of adjusting from the high SOC side or the high voltage side to the state Y in the first adjustment process described above, by performing discharge and charge sequentially, the state Y is adjusted again from the low SOC side or the low voltage side.

[0048] (ii) In the case of adjusting to state Y from the low SOC side or low voltage side in the first adjustment process described above, by performing charging and discharging sequentially, state Y is adjusted back from the high SOC side or high voltage side.

[0049] Here, the charging and discharging process in the second adjustment step is explained when the battery state is defined by the State of Charge (SOC). Furthermore, when the first resistance value is the charging resistance, although the battery state (e.g., SOC) after the first measurement step is considered to be higher than state Y, the difference is considered to be minimal. Similarly, when the first resistance value is the discharging resistance, although the battery state (e.g., SOC) after the first measurement step is considered to be lower than state Y, the difference is considered to be minimal. Therefore, in this disclosure, it can be understood that the battery state after the first measurement step is substantially the same as state Y.

[0050] Figure 6 This is a diagram illustrating the second adjustment step in this disclosure. Specifically, Figure 6 (a) is a diagram illustrating the charging and discharging process of the second adjustment step conforming to (i) above. Additionally, Figure 6 (b) is a diagram illustrating the charging and discharging process conforming to the second adjustment step described in (ii) above. For example, as... Figure 6 As shown in (a), when adjusting from the high SOC side to state Y in the first adjustment step S2, in the second adjustment step S4, the battery is discharged to state P2, which is a state with a lower SOC than state Y, and then charged from state P2 to state Y. Therefore, the second resistance value, described later, can be measured as the resistance value after charging. Furthermore, it is preferable, for example, that the SOC of state P2 is 5% or more lower than that of state Y. Additionally, state P2 can be the same as state P1 described above, or it can be a different state.

[0051] On the other hand, for example, such as Figure 6 As shown in (b), in the first adjustment step S2, after adjusting from the low SOC side to state Y, in the second adjustment step S4, the battery is charged to state Q2, which has a higher SOC than state Y, and then discharged from state Q2 to state Y. Therefore, the second resistance value described later can be measured as the resistance value after discharge. Furthermore, it is preferable, for example, that the SOC of state Q2 is 5% or more higher than that of state Y. Additionally, state Q2 can be the same as state Q1 described above, or it can be a different state.

[0052] In the second adjustment step, the charging and discharging current values ​​are, for example, 1 / 5C or more, or 1 / 4C or more, or 1 / 3C or more. On the other hand, the charging and discharging current values ​​are, for example, 1C or less, or 2 / 3C or less. Furthermore, the charging and discharging current values ​​in the second adjustment step can be the same as or different from the charging and discharging current values ​​in the first adjustment step.

[0053] 5. Second measurement procedure

[0054] The second measurement step in this disclosure is to measure the resistance value of the battery under state Y after adjustment by the second adjustment step described above, as a second resistance value. If the first resistance value is a charging resistance value, it is preferable that the second resistance value is also a charging resistance value. Similarly, if the first resistance value is a discharging resistance value, it is preferable that the second resistance value is also a discharging resistance value. The method for measuring the second resistance value is not particularly limited; for example, the IV method can be used.

[0055] 6. Determine the process

[0056] The determination process in this disclosure is a process of determining whether the battery is a genuine product based on the first resistance value and the second resistance value mentioned above.

[0057] In the judgment process, whether a battery is a genuine product is determined by using any method with a first resistance value and a second resistance value. For example, if the first resistance value is set as R1 and the second resistance value is set as R2, the determination can be made based on the absolute value of the difference between R1 and R2 (|R1-R2|: resistance change) or the ratio of the first resistance value R1 to the second resistance value R2 (R1 / R2: resistance change rate). For example, as... Figure 7 As shown, for each type of standard battery with various capacities (e.g., capacity per unit area), the rate of resistance change is calculated under a predetermined condition Y (e.g., SOC 50%), and a graph of the rate of resistance change relative to capacity is generated. Next, the rate of resistance change calculated for a target battery with a predetermined capacity is compared to the aforementioned graph. Then, the rate of resistance change of the standard battery and the target battery under the predetermined capacity is compared. If the absolute value of the difference between the two is below a reference value, the target battery is determined to be a standard product; if the absolute value of the difference exceeds the reference value, the target battery is determined to be a non-standard product. For example, in... Figure 7 Among them, battery A and battery B can be identified as genuine products, while battery C can be identified as a non-genuine product.

[0058] The reference value can be adjusted appropriately based on the type and capacity of the battery. For example, if the resistance change rate and resistance change amount of a regular product are set as T, the reference value is, for example, 0.01T or higher and 0.1T or lower.

[0059] 7. Battery

[0060] The battery subject to this disclosure can be a liquid battery with a liquid electrolyte or an all-solid battery with a solid electrolyte. Additionally, the battery can be, for example, a lithium-ion battery or a sodium-ion battery that uses cations as charge carriers, or a fluoride-ion battery that uses anions as charge carriers.

[0061] Furthermore, the preferred battery in this disclosure has a capacity per unit area (mAh / cm²). 2 The capacity per unit area is larger. Because a larger capacity per unit area results in a thicker electrode layer, uneven ion concentration is more easily generated during charging and discharging, leading to a larger change in resistance (|R1-R2| or R1 / R2). Consequently, it becomes easier to distinguish between genuine and counterfeit products. Battery capacity per unit area (mAh / cm²) 2 For example, 1mAh / cm 2 above.

[0062] Furthermore, this disclosure is not limited to the embodiments described above. The embodiments described above are illustrative examples. Any technical solution that has a substantially the same structure as the technical concept described in the claims of this disclosure and achieves the same effect is included within the technical scope of this disclosure.

Claims

1. A method for determining whether a battery is a genuine product, including: The process involves determining the state of the battery as either the state of charge (SOC) or a voltage-defined state X. The first adjustment step involves charging and discharging the battery in state X to adjust the state of the battery to state Y. The first measurement step involves measuring the resistance value of the battery under state Y after adjustment through the first adjustment step, and using this resistance value as the first resistance value. The second adjustment step involves charging and discharging the battery after the first measurement step according to either (i) or (ii) below, thereby readjusting the battery's state back to state Y. (i) If the state is adjusted from the high SOC side or the high voltage side to state Y in the first adjustment step, the state is adjusted back to state Y from the low SOC side or the low voltage side by performing discharge and charge sequentially. (ii) If the state Y is adjusted from the low SOC side or the low voltage side in the first adjustment process, the state Y is adjusted again from the high SOC side or the high voltage side by performing charging and discharging in sequence. The second measurement step involves measuring the resistance value of the battery in state Y after adjustment through the second adjustment step, and using this resistance value as the second resistance value. as well as The determination process involves using the first resistance value and the second resistance value to determine whether the battery is a genuine product.

2. The determination method according to claim 1, The states X and Y are defined by the charging state, i.e., SOC.

3. The determination method according to claim 1, The states X and Y are defined by the voltage.

4. The determination method according to any one of claims 1 to 3, In the first adjustment step, at least one of the charging and discharging is performed with a current value of 1 / 3C or higher.

5. The determination method according to any one of claims 1 to 3, In the second adjustment step, the charging and discharging are performed with a current value of 1 / 3C or higher.

6. The determination method according to any one of claims 1 to 3, In the second adjustment step, the charging and discharging processes that conform to (i) are performed.

7. The determination method according to any one of claims 1 to 3, In the second adjustment step, the charging and discharging processes that conform to (ii) are performed.

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