JPWO2015136930A1 - Battery inspection apparatus and battery inspection method - Google Patents

Abstract

The battery inspection device (10) is a battery inspection device for inspecting a battery, and in the charging / discharging process of the battery, an external voltage obtained by superimposing an AC voltage on a DC voltage for balancing the output voltage of the battery. And a measurement unit (12) for measuring a magnetic field outside the battery in a state where an external voltage obtained by superimposing an AC voltage on a DC voltage is applied to the battery. Including a shielding unit that prevents a current inside the battery from generating a magnetic field outside the battery, and the application unit (11) is an alternating current corresponding to a second frequency lower than the first frequency determined based on the characteristics of the shielding unit. An external voltage in which the voltage is superimposed on the DC voltage is applied to the battery.

Description

  The present invention relates to a battery inspection apparatus and a battery inspection method for inspecting a battery.

  In recent years, dendrite generated in a lithium battery has been regarded as a problem because it may cause a short circuit in the battery and an explosion of the battery. Therefore, an effective inspection method for preventing such a short circuit has been studied. In this regard, Patent Document 1 discloses a method for inspecting the state of a battery using X-rays, visible light, ultrasonic waves, or the like.

Special table 2012-524385 gazette

  However, visible light and microwaves are unlikely to pass through the metal covering the battery. Therefore, it is difficult to inspect the state in the battery with visible light or microwaves.

  Although it is possible to inspect the state in the battery with X-rays, the electrical state in the battery with X-rays can be inspected that foreign matter is mixed in the battery with X-rays. It is difficult to inspect. Therefore, it is difficult to inspect the electrical state in the battery using any of X-rays, visible light, and microwaves.

  On the other hand, in order to investigate the cause of a short circuit or the like in the battery, it may be useful to inspect an electrical state that changes in the battery during the charge and discharge process of the battery.

  Therefore, the present invention provides a battery inspection device and a battery inspection method that can appropriately acquire information corresponding to the electrical state in the battery during the charge / discharge process of the battery.

  For example, a battery inspection apparatus according to an aspect of the present invention is a battery inspection apparatus that inspects a battery, and in a charging / discharging process of the battery, an alternating current is applied to a direct current voltage for balancing the output voltage of the battery. An application unit that applies an external voltage superimposed on the battery to the battery, and a measurement unit that measures a magnetic field outside the battery in a state where the external voltage obtained by superimposing the AC voltage on the DC voltage is applied to the battery. The battery includes a shielding unit that prevents current inside the battery from generating a magnetic field outside the battery, and the application unit is configured to have a first frequency determined based on characteristics of the shielding unit. The external voltage obtained by superimposing the alternating voltage corresponding to the second frequency lower than the direct current voltage is applied to the battery.

  Thereby, the battery test | inspection apparatus can measure appropriately the magnetic field which the electric current which flows in the inside of a battery produces | generates the exterior (battery periphery) of a battery in the middle of charging / discharging. Therefore, the battery inspection apparatus can appropriately acquire information corresponding to the electrical state in the battery in the charge / discharge process of the battery. Moreover, the battery inspection apparatus can suppress the influence of a shielding part by using a frequency lower than the frequency based on the characteristic of a shielding part, and can measure a magnetic field appropriately.

  For example, the characteristics of the shielding part correspond to the conductivity of the shielding part, the permeability of the shielding part, and the thickness of the shielding part, and the application part includes the conductivity, the permeability, and the thickness. The external voltage obtained by superimposing the AC voltage corresponding to the second frequency lower than the first frequency determined based on the DC voltage on the DC voltage may be applied to the battery.

  Thereby, the battery test | inspection apparatus can suppress the influence of a shielding part using the frequency lower than the frequency based on the electrical conductivity of a shielding part, magnetic permeability, and the thickness.

For example, the application unit is expressed by 1 / (πσμd ² ) when the conductivity is expressed by σ, the magnetic permeability is expressed by μ, and the thickness is expressed by d. The external voltage obtained by superimposing the AC voltage corresponding to the second frequency lower than the first frequency on the DC voltage may be applied to the battery.

  Thereby, the battery test | inspection apparatus can suppress the influence of a shielding part using the frequency defined more specifically, and can measure a magnetic field appropriately.

  For example, the battery inspection apparatus may further include a generation unit that generates an image indicating a magnetic field distribution or a current distribution inside the battery based on the magnetic field measured by the measurement unit.

  Thereby, the battery test | inspection apparatus can produce | generate the image from which a user can recognize the state in a battery visually.

  For example, the battery inspection apparatus may further include a display unit that displays the image generated by the generation unit.

  Thereby, the battery test | inspection apparatus can display the image which a user can recognize visually the state in a battery.

  For example, the application unit intermittently applies the external voltage obtained by superimposing the AC voltage on the DC voltage in the charge / discharge process of the battery to the battery, whereby the AC voltage is applied to the DC voltage in a plurality of periods. May be applied to the battery, and the measurement unit may measure a magnetic field outside the battery in each of the plurality of periods.

  Thereby, the battery test | inspection apparatus can measure appropriately the magnetic field which an electric current produces | generates at each of several time points in the middle of charging / discharging.

  For example, the battery inspection apparatus may further include a video including a plurality of images each indicating a magnetic field distribution or a current distribution inside the battery based on the magnetic fields measured in the plurality of periods by the measurement unit. You may provide the production | generation part to produce | generate.

  Thereby, the battery test | inspection apparatus can produce | generate the image | video which a user can recognize visually the change of the state in a battery.

  For example, the battery inspection apparatus may further include a display unit that displays the video generated by the generation unit.

  Thereby, the battery test | inspection apparatus can display the image | video which a user can recognize visually the change of the state in a battery.

  For example, a battery inspection method according to an aspect of the present invention is a battery inspection method for inspecting a battery, and in a charge / discharge process of the battery, an AC voltage is applied to a DC voltage for balancing the output voltage of the battery. An application step of applying an external voltage superimposed on the battery to the battery; and a measurement step of measuring a magnetic field outside the battery in a state where the external voltage obtained by superimposing the AC voltage on the DC voltage is applied to the battery. And the battery includes a shielding part that prevents a current inside the battery from generating a magnetic field outside the battery, and the application step includes a first frequency determined based on characteristics of the shielding part. The external voltage obtained by superimposing the alternating voltage corresponding to the second frequency lower than the direct current voltage is applied to the battery.

  Thereby, it is possible to appropriately measure the magnetic field generated outside the battery by the current flowing inside the battery at the midpoint of charging and discharging. Therefore, it is possible to appropriately acquire information corresponding to the electrical state in the battery during the charging / discharging process of the battery.

  Note that these comprehensive or specific aspects may be realized by a system, an apparatus, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM. The present invention may be realized by any combination of a method, an integrated circuit, a computer program, and a recording medium.

  With the battery inspection device and the battery inspection method according to the present invention, it is possible to appropriately acquire information corresponding to the electrical state in the battery during the charge / discharge process of the battery.

FIG. 1 is a configuration diagram showing a battery inspection apparatus according to an embodiment. FIG. 2 is a flowchart showing the operation of the battery inspection apparatus according to the embodiment. FIG. 3 is a schematic diagram showing the battery inspection apparatus according to the embodiment. FIG. 4 is a diagram showing a state in which the battery according to the embodiment is being inspected. FIG. 5 is a diagram illustrating a current transition according to the embodiment. FIG. 6 is a diagram showing a transition of the storage rate according to the embodiment. FIG. 7 is a diagram illustrating a circuit for applying an alternating voltage according to the embodiment.

  Hereinafter, embodiments and the like will be specifically described with reference to the drawings. It should be noted that the embodiments and the like described below show a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of constituent elements, steps, order of steps, and the like shown in the following embodiments and the like are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments and the like, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

  Further, ordinal numbers such as first, second, and third may be added to, replaced with, or removed from the components and the like in the following description.

(Embodiment)
First, an outline of the battery inspection apparatus according to the present embodiment will be described. The battery inspection apparatus according to the present embodiment inspects a battery without destroying the battery. X-rays, visible light, microwaves, and the like may be used as technical elements used for such nondestructive inspection. However, it is difficult to inspect the electrical state in the battery using any of X-rays, visible light, and microwaves. Therefore, the battery inspection apparatus according to the present embodiment uses a magnetic field.

  Specifically, the current flowing inside the battery generates a magnetic field outside the battery (around the battery). The relationship between the current J and the magnetic field H in the steady state is expressed by ΔH = − (∇ × J) based on Maxwell's equation. Based on such a relationship, it is possible to estimate the current flowing inside the battery from the magnetic field outside the battery. The battery inspection apparatus according to the present embodiment inspects the electrical state of the battery by measuring a magnetic field.

  On the other hand, in the charging / discharging process of the battery, the electrical state in the battery changes. Observing the state that changes during the charging / discharging process of the battery is effective for checking the reliability of the battery. However, since the measurement of the magnetic field takes a considerable amount of time, the electrical state in the battery may change while the magnetic field is being measured during the charge / discharge process of the battery. When the electrical state in the battery changes, the magnetic field also changes, so it is difficult to appropriately measure the magnetic field.

  In such a situation, it is possible to stop the change of the electrical state in the battery by stopping the charging / discharging of the battery. However, when charging / discharging is simply stopped, no current flows and no magnetic field is generated. Therefore, it is not appropriate to measure the magnetic field while charging / discharging is simply stopped.

  Therefore, the battery inspection apparatus according to the present embodiment pauses (suppresses) charging and discharging and applies an alternating voltage in the charging and discharging process. The current flowing by the alternating voltage generates a magnetic field. The battery inspection apparatus according to the present embodiment can appropriately inspect the state of the battery by measuring the magnetic field generated by the current flowing by the alternating voltage. Hereinafter, a specific configuration of the battery inspection apparatus according to the present embodiment will be described.

  The battery to be inspected is a battery that can be charged or discharged (charged / discharged), and such a battery is also called a secondary battery or a storage battery, for example.

  FIG. 1 is a configuration diagram showing a battery inspection apparatus according to the present embodiment. The battery inspection apparatus 10 shown in FIG. 1 includes an application unit 11, a measurement unit 12, a generation unit 13, and a display unit 14.

  The application unit 11 is a device that applies a voltage to the battery. For example, the application unit 11 is a generator that generates voltage and current.

  The measurement unit 12 is a device that measures a magnetic field. For example, the measurement unit 12 is a measuring device that includes a sensor that senses a magnetic field and measures the magnetic field sensed by the sensor.

  The generation unit 13 is an apparatus that generates an image (image data) or a video (video data). For example, the generation unit 13 is an information processing unit that generates an image or a video.

  The display unit 14 is a device that displays an image or video. For example, the display unit 14 is a device that has a screen and displays an image or video on the screen.

  The battery inspection apparatus 10 may include only a part of the application unit 11, the measurement unit 12, the generation unit 13, and the display unit 14. That is, the battery inspection apparatus 10 may not include all of the application unit 11, the measurement unit 12, the generation unit 13, and the display unit 14. For example, the battery inspection device 10 may include the application unit 11 and the measurement unit 12, and an external device different from the battery inspection device 10 may include the generation unit 13 and the display unit 14.

  FIG. 2 is a flowchart showing the operation of the battery inspection apparatus 10 shown in FIG. First, the application part 11 applies an external voltage to a battery in the charging / discharging process of a battery (S11). Here, the external voltage applied to the battery is a voltage obtained by superimposing an AC voltage on a DC voltage for balancing the output voltage of the battery. That is, the application unit 11 pauses charging / discharging of the battery and applies an AC voltage to the battery. Thereby, a change in the electrical state of the battery is suppressed, and a current flowing inside the battery generates a magnetic field.

  Next, the measurement part 12 measures the magnetic field outside a battery in the state in which the external voltage which superimposed the alternating voltage on the direct current voltage was applied to the battery (S12). That is, the measurement unit 12 measures the magnetic field in a state where charging / discharging of the battery is stopped and an AC voltage is applied to the battery. At this time, since the measurement unit 12 can measure the magnetic field in a state in which the change is suppressed, it can appropriately measure the magnetic field over a sufficient time.

  Next, the generation unit 13 generates an image or video showing the magnetic field distribution or current distribution inside the battery based on the magnetic field measured by the measurement unit 12 (S13). Next, the display unit 14 displays the image or video generated by the generation unit 13 (S14).

  With the above-described configuration and operation, the battery inspection device 10 can appropriately acquire information corresponding to the electrical state in the battery during the charging / discharging process of the battery. Next, the battery inspection apparatus 10 will be described in more detail.

  FIG. 3 is a schematic diagram showing the battery inspection apparatus 10 shown in FIG. FIG. 3 shows the battery 21 and the battery inspection device 10. The battery inspection device 10 includes an application unit 11, a measurement unit 12, a generation unit 13, and a display unit 14.

  The application unit 11 is a device that applies a voltage to the battery 21 as described above. For example, the application unit 11 is a voltage generator as shown in FIG. In the example of FIG. 3, the application unit 11 applies a voltage to the battery 21 via a conducting wire.

  The measurement unit 12 includes a TMR sensor (Tunneling Magneto Resistive Sensor) 24 as a probe. The TMR sensor 24 is an example, and other types of sensors may be used. The measurement unit 12 has a slidable mechanism. Thereby, the measurement unit 12 can scan the vicinity of the battery 21 using the TMR sensor 24.

  The measurement unit 12 includes a turntable 25. The turntable 25 is a stand for placing an inspection object (battery 21), and has a rotatable mechanism. Thereby, the measurement part 12 can scan the vicinity of the battery 21 with various rotation angles.

  The generation unit 13 generates an image indicating the magnetic field distribution or current distribution inside the battery 21 based on the magnetic field measured by the measurement unit 12. For example, the generation unit 13 is an electronic computer (computer) as shown in FIG.

  The display unit 14 displays the image generated by the generation unit 13. For example, the display unit 14 is a display device (display) having a screen as shown in FIG.

  The battery 21 to be inspected by the battery inspection device 10 is a lithium battery or a lithium ion battery. The battery 21 has a pair of electrode terminals 22 and 23. Each of the electrode terminals 22 and 23 and the application part 11 are connected through a conducting wire. Then, the measurement unit 12 measures the magnetic field around the battery 21 with the application unit 11 applying an external voltage to the battery 21.

  In FIG. 3, the application unit 11, the measurement unit 12, the generation unit 13, and the display unit 14 have independent structures. However, all or part of the application unit 11, the measurement unit 12, the generation unit 13, and the display unit 14 may have an integral structure.

  FIG. 4 is a diagram showing a state in which the battery 21 shown in FIG. 3 is being inspected. The battery 21 shown in FIG. 4 includes a pair of electrode terminals 22 and 23, a pair of electrode plates 33 and 34, an electrolyte 36, and a metal package 37. The pair of electrode plates 33 and 34 and the electrolyte 36 are covered with a metal package 37.

  The measurement unit 12 measures the magnetic field via the TMR sensor 24 on the scanning target surface 31 above the battery 21 placed on the turntable 25. The generation unit 13 acquires information on the magnetic field measured on the scan target surface 31 from the measurement unit 12 and analyzes the acquired information, thereby acquiring information on the magnetic field on the reconstruction target surface 32. Good. That is, the generation unit 13 may acquire information on the magnetic field of the reconstruction target surface 32 based on the information on the magnetic field of the scanning target surface 31.

  Methods for analyzing magnetic field information are described in International Publication No. 2008/123432 (hereinafter, Patent Document 2), International Publication No. 2012/153696 (hereinafter, Patent Document 3), and the like. Specifically, Patent Document 2 and Patent Document 3 describe a method of analyzing magnetic field information using Maxwell's equations.

  The generation unit 13 may use the method described in Patent Document 2, Patent Document 3, and the like. Or the measurement part 12 may acquire the information of the magnetic field of the reconstruction object surface 32 using the method as described in patent document 2 or patent document 3. Then, the generation unit 13 may acquire information on the magnetic field of the reconstruction target surface 32 from the measurement unit 12.

  The current flowing inside the battery 21 generates a magnetic field outside the battery 21. The measuring unit 12 measures the magnetic field generated by the current flowing inside the battery 21 outside the battery 21. If the current flowing inside the battery 21 changes, the magnetic field outside the battery 21 also changes.

  For example, in the charge / discharge process of the battery 21, dendrites 35 may be formed inside the battery 21 by depositing metal on the electrode plate 33 or the electrode plate 34. That is, in the charging / discharging process of the battery 21, the dendrite 35 may be generated and grow.

  The conductivity of the dendrite 35 is higher than that of the electrolyte 36. Therefore, if the dendrite 35 is generated inside the battery 21, the electrical state inside the battery 21 changes. Thereby, the magnetic field outside the battery 21 also changes. If the battery inspection apparatus 10 can appropriately measure the magnetic field outside the battery 21, the state of generation and growth of the dendrite 35 can be inspected.

  Observing the generation and growth of the dendrite 35 accompanying the charging / discharging of the battery 21 may be useful for suppressing the generation and growth of the dendrite 35 accompanying the charging / discharging of the battery 21. On the other hand, as the dendrite 35 is generated and grown as the battery 21 is charged / discharged, the electrical state inside the battery 21 changes, and the magnetic field generated outside the battery 21 also changes. It is difficult to properly measure a magnetic field that changes over time.

  Therefore, the battery inspection device 10 pauses charging / discharging of the battery 21 in the charging / discharging process of the battery 21. Thereby, generation | occurrence | production and growth of the dendrite 35 are suppressed, and the change of the electrical state inside the battery 21 is suppressed. However, if no current flows inside the battery 21, no magnetic field is generated outside the battery 21. Therefore, the battery inspection apparatus 10 applies an alternating voltage to the battery 21 in a state where charging / discharging of the battery 21 is suspended.

  The current flowing inside the battery 21 by the AC voltage does not promote the generation and growth of the dendrite 35. Therefore, the electrical state inside the battery 21 is stabilized. Further, the current flowing inside the battery 21 by the AC voltage can generate a magnetic field outside the battery 21. In addition, since the electrical state inside the battery 21 is stable, changes in the magnetic field over time are suppressed. Therefore, the battery inspection apparatus 10 can appropriately measure the magnetic field in the charge / discharge process of the battery 21.

  That is, the battery inspection apparatus 10 pauses charging / discharging in the charging / discharging process of the battery 21 and applies an alternating voltage to the battery 21 to suppress the generation and growth of the dendrite 35 and to apply the magnetic field over time. It can be measured appropriately.

FIG. 5 is a diagram showing a transition of the current flowing in the battery 21 shown in FIG. In this example, the battery testing device 10, a DC voltage is applied to the battery 21 to the time T _1. The battery testing device 10, an AC voltage is applied to the battery 21 from time _{T 1} to time _{T 2.} The battery testing device 10 applies a DC voltage to the battery 21 from the time _{T 2,} until time _{T 3.} The battery testing device 10, an AC voltage is applied to the battery 21 from time _{T 3} to time _{T 4.} The battery testing device 10 applies a DC voltage to the battery 21 from time _{T 4.}

Thus, charging of the battery 21 is performed until time _{T 1.} The charging of the battery 21 is inhibited from time _{T 1} to time _{T 2.} The charging of the battery 21 is performed from time _{T 2,} until time _{T 3.} The charging of the battery 21 is inhibited from time _{T 3} to time _{T 4.} The charging of the battery 21 is performed from time _{T 4.}

  The dendrite grows during the charging period. And the growth of dendrites stops during the period when charging is suppressed. The battery inspection device 10 measures the magnetic field around the battery 21 during the period when the growth of dendrites is stopped. That is, the battery inspection apparatus 10 measures the magnetic field in a state where an AC voltage is applied to the battery 21.

  FIG. 6 is a diagram showing a transition of the storage rate of the battery 21 shown in FIG. The example of FIG. 6 corresponds to the example of FIG. In FIG. 6, the storage rate is used on the vertical axis instead of the current. As shown in FIG. 6, the power storage rate increases during the charging period. And in the period when charge is suppressed, the increase in an electrical storage rate is suppressed.

  The battery inspection apparatus 10 can inspect the dendrite growth at a point in the middle of the charging process by measuring the magnetic field in a period in which the increase in the storage rate is suppressed. And the battery test | inspection apparatus 10 can test | inspect the growth process of the dendrite in a charging process by suppressing the increase in an electrical storage rate and measuring a magnetic field in each of several time points in the middle of a charging process.

  Further, the battery inspection device 10 may measure the magnetic field in each of the plurality of periods in which the increase in the power storage rate is suppressed, and generate an image indicating the magnetic field distribution or the current distribution based on the measured magnetic field. Good. That is, the battery inspection apparatus 10 may generate a plurality of images corresponding to a plurality of points in the middle of the charging process. And the battery test | inspection apparatus 10 may produce | generate the image | video containing the produced | generated several image, and may display the produced | generated image | video. Thereby, the battery test | inspection apparatus 10 can display the process in which a dendrite grows as an image | video.

  5 and 6 show transitions corresponding to the charging process. However, the battery inspection apparatus 10 can perform the same operation as the charging process in the discharging process. That is, the battery inspection apparatus 10 suppresses the discharge of the battery 21 and applies an AC voltage to the battery 21 in the discharge process of the battery 21. The battery inspection apparatus 10 can appropriately measure the magnetic field in the discharging process of the battery 21 by measuring the magnetic field in this state.

  Next, a more specific configuration for applying an AC voltage to the battery 21 will be described with reference to FIG. FIG. 7 is a diagram showing a circuit for applying an AC voltage to the battery 21 shown in FIG.

FIG. 7 shows the battery 21 and the application unit 11. Further, a capacitor C _b , an electromotive force ν _o , an internal resistance γ _b , a DC voltage ν _e , an AC voltage ν _a cos ωt, and an external resistance γ are shown. The capacitor C _b , the electromotive force ν _o , and the internal resistance γ _b are included in the battery 21. The internal resistance γ _b , the DC voltage ν _e , and the AC voltage ν _a cos ωt are included in the application unit 11. AC voltage _ν a _cosωt of t represents the time, the ω of the AC voltage _ν a _cosωt, shows the angular frequency.

The application unit 11 converts the DC voltage ν _e = ν _o (T) into an AC voltage ν _a cosωt for balancing the output voltage ν _o (T) of the battery 21 at a predetermined time t = T in the charge / discharge process. Is applied to the battery 21 with the external voltage ν _E (t) = ν _e + ν _a cos ωt superimposed thereon. For example, the external voltage ν _E (t) is obtained by an external modulation bias (external modulation circuit and bias circuit).

In other words, the application unit 11 repeats charging and discharging at the angular frequency ω in a state in which the application unit 11 is balanced with respect to the output voltage ν _o (T) of the battery 21. The measurement unit 12 measures a magnetic field corresponding to a charge / discharge response component repeated at an angular frequency ω.

However, it is assumed that the battery 21 has a shielding portion that prevents the current inside the battery 21 from generating a magnetic field outside the battery 21. For example, when the frequency f (f = ω / 2π) of the AC voltage ν _a cos ωt is high, the magnetic field is shielded by the shielding portions such as the electrode plates 33 and 34 and the metal package 37 and does not leak outside the battery 21. .

Therefore, the application unit 11 superimposes the AC voltage ν _a cosωt corresponding to a frequency lower than the frequency determined based on the characteristics of the shielding unit on the DC voltage ν _e . For example, the characteristics of the shielding part are the conductivity of the shielding part, the permeability of the shielding part, and the thickness (depth) of the shielding part.

Specifically, when the conductivity of the shielding part is represented by σ, the magnetic permeability of the shielding part is represented by μ, and the thickness of the shielding part is represented by d, the application unit 11 has f <1 / ( An alternating voltage ν _a cosωt corresponding to the frequency f satisfying πσμd ² ) is superimposed. The thickness d of the shielding part is, for example, the total of the thickness of the electrode plate 33 and the thickness of the metal package 37.

Further, the application unit 11 may superimpose an AC voltage ν _a cosωt corresponding to a frequency lower than the above-described frequency determined based on the characteristics of the shielding unit and close to the above-described frequency. Thereby, the influence of charging / discharging is suppressed. For example, the application unit 11 may superimpose an AC voltage ν _a cosωt corresponding to a frequency lower than the above frequency and higher than ½ of the above frequency. Specifically, the application unit 11 may superimpose an AC voltage ν _a cosωt corresponding to the frequency f satisfying 1 / (2πσμd ² ) <f <1 / (πσμd ² ).

  Also, some of the conductivity of the shielding part, the magnetic permeability of the shielding part, and the thickness of the shielding part may be used as the characteristics of the shielding part, and other attributes of the shielding part may be used as the characteristics of the shielding part. It may be used.

Further, the application unit 11 may adjust the frequency of the AC voltage ν _a cosωt to a frequency lower than the frequency determined based on the characteristics of the shielding unit. For example, the application unit 11 adjusts the frequency low so that a magnetic field is generated outside the battery 21, that is, a magnetic field is generated beyond the shielding unit. Further, the application unit 11 may adjust the frequency so that the measurement unit 12 measures a magnetic field equal to or higher than a predetermined reference.

  After the measurement of the magnetic field, the application unit 11 stops the superposition of the alternating voltage and controls so that only one of charging and discharging is performed. For example, the application unit 11 applies a DC voltage larger than the output voltage of the battery 21 to charge the battery 21. Alternatively, the application unit 11 applies a DC voltage smaller than the output voltage of the battery 21 to discharge the battery 21. Alternatively, the application unit 11 may discharge the battery 21 without applying a voltage.

  Based on the above configuration, the application unit 11 intermittently applies an external voltage in which an AC voltage is superimposed on a DC voltage for balancing the output voltage of the battery 21 in the charge / discharge process. The application unit 11 may apply an external voltage on which an alternating voltage is superimposed periodically (periodically) or irregularly. The application unit 11 may automatically apply an external voltage on which an alternating voltage is superimposed, or may apply it based on a manual operation. The measurement unit 12 measures the magnetic field around the battery 21 in a state where an external voltage on which an alternating voltage is superimposed is applied.

  For example, each time for measuring the magnetic field in the charge / discharge process may be determined in advance. In this case, the application unit 11 applies an external voltage on which an alternating voltage is superimposed to the battery 21 at each predetermined time in the charge / discharge process. And the measurement part 12 measures a magnetic field at each predetermined time in the charging / discharging process. After the measurement, the application unit 11 controls so that normal charging / discharging is performed. Thereby, the battery test | inspection apparatus 10 can measure the magnetic field corresponding to each predetermined time in a charging / discharging process.

  Each time for measuring the magnetic field in the charge / discharge process may be determined based on the characteristics of the output voltage of the battery 21 or may be determined based on the characteristics of time. That is, the battery inspection apparatus 10 may measure the magnetic field for each predetermined output voltage, or may measure the magnetic field for each predetermined time interval.

  And the production | generation part 13 respond | corresponds to the some time in a charging / discharging process, and may produce | generate the some image which each shows magnetic field distribution or electric current distribution. Further, the generation unit 13 may generate a video (moving image) including a plurality of images and showing a change in the magnetic field distribution or the current distribution by connecting the plurality of generated images. And the display part 14 may display the image | video which shows the change of magnetic field distribution or electric current distribution. Thereby, the user of the battery test | inspection apparatus 10 can observe the growth process of a dendrite exactly.

  Note that the application unit 11 and the measurement unit 12 may be linked using a synchronization signal. That is, the AC voltage superposition and the magnetic field measurement may be controlled to start at the same time and end at the same time by the synchronization signal.

  Although the battery inspection apparatus according to the present invention has been described based on the embodiment, the present invention is not limited to the embodiment. Embodiments obtained by subjecting the embodiments to modifications conceived by those skilled in the art and other embodiments realized by arbitrarily combining a plurality of components in the embodiments are also included in the present invention.

  For example, a process performed by a specific processing unit may be performed by another processing unit. In addition, the order in which the processes are executed may be changed, or a plurality of processes may be executed in parallel.

  Further, the battery inspection device may be expressed as a battery inspection system. The application unit may be expressed as an application device or an application circuit. The measurement unit may be expressed as a measurement device or a measurement circuit. The generation unit may be expressed as a generation device or a generation circuit. The display unit may be expressed as a display device or a display circuit.

  In addition, the present invention can be realized not only as a battery inspection apparatus but also as a method using a processing unit constituting the battery inspection apparatus as a step. For example, these steps are performed by a computer. The present invention can be realized as a program for causing a computer to execute the steps included in these methods. Furthermore, the present invention can be realized as a non-transitory computer-readable recording medium such as a CD-ROM in which the program is recorded.

  The plurality of components included in the battery inspection apparatus may be realized as an LSI (Large Scale Integration) that is an integrated circuit. These components may be individually made into one chip, or may be made into one chip so as to include a part or all of them. Although referred to here as an LSI, it may be referred to as an IC (Integrated Circuit), a system LSI, a super LSI, or an ultra LSI depending on the degree of integration.

  Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. A programmable programmable gate array (FPGA) or a reconfigurable processor capable of reconfiguring connection and setting of circuit cells inside the LSI may be used.

  Furthermore, if integrated circuit technology that replaces LSI emerges as a result of advances in semiconductor technology or other derived technology, it is natural that even if the technology is used, the components included in the battery testing apparatus can be integrated into an integrated circuit. Good.

  The battery inspection apparatus and the battery inspection method according to the present invention can be used for battery inspection, and can be used for battery development and improvement.

DESCRIPTION OF SYMBOLS 10 Battery inspection apparatus 11 Application part 12 Measurement part 13 Generation part 14 Display part 21 Battery 22, 23 Electrode terminal 24 TMR sensor (Tunneling Magneto Resistive Sensor)
25 Turntable 31 Scan target surface 32 Reconstruction target surface 33, 34 Electrode plate 35 Dendrite 36 Electrolyte 37 Metal package

For example, a battery inspection apparatus according to an aspect of the present invention is a battery inspection apparatus that inspects a battery, and in the charge / discharge process of the battery, pauses the charge / discharge and balances the output voltage of the battery. An application unit that applies an external voltage in which an alternating voltage is superimposed on a direct current voltage to be applied to the battery, and an external part of the battery in a state in which the external voltage in which the alternating voltage is superimposed on the direct current voltage is applied to the battery. The battery includes a shielding unit that prevents a current inside the battery from generating a magnetic field outside the battery, and the application unit has characteristics of the shielding unit. The external voltage obtained by superimposing the AC voltage corresponding to the second frequency lower than the first frequency determined on the basis of the DC voltage is applied to the battery.

For example, in the charging / discharging process of the battery, the applying unit pauses the charging / discharging, and intermittently applies the external voltage obtained by superimposing the AC voltage on the DC voltage to the battery, thereby providing a plurality of periods. The external voltage obtained by superimposing the alternating voltage on the direct current voltage may be applied to the battery, and the measurement unit may measure a magnetic field outside the battery in each of the plurality of periods.

For example, a battery inspection method according to an aspect of the present invention is a battery inspection method for inspecting a battery, wherein charging / discharging is suspended in a charging / discharging process of the battery, and a balance is achieved with respect to the output voltage of the battery. An application step of applying to the battery an external voltage obtained by superimposing an alternating voltage on a direct current voltage, and a state where the external voltage obtained by superimposing the alternating voltage on the direct current voltage is applied to the battery. Measuring the magnetic field of the battery, wherein the battery includes a shielding part that prevents a current inside the battery from generating a magnetic field outside the battery, and the applying step takes into account the characteristics of the shielding part. The external voltage obtained by superimposing the AC voltage corresponding to the second frequency lower than the first frequency determined on the basis of the DC voltage is applied to the battery.

Claims (9)

A battery inspection device for inspecting a battery,
In the charging / discharging process of the battery, an application unit for applying an external voltage obtained by superimposing an AC voltage on a DC voltage for balancing the output voltage of the battery;
A measurement unit that measures a magnetic field outside the battery in a state where the external voltage obtained by superimposing the AC voltage on the DC voltage is applied to the battery;
The battery includes a shielding unit that prevents a current inside the battery from generating a magnetic field outside the battery,
The said application part applies the said external voltage which superimposed the said alternating voltage corresponding to the 2nd frequency lower than the 1st frequency defined based on the characteristic of the said shielding part on the said DC voltage to the said battery. Battery test | inspection apparatus. The characteristics of the shielding part correspond to the conductivity of the shielding part, the permeability of the shielding part, and the thickness of the shielding part,
The applying unit includes the external voltage obtained by superimposing the AC voltage corresponding to the second frequency lower than the first frequency determined based on the conductivity, the magnetic permeability, and the thickness on the DC voltage. The battery inspection apparatus according to claim 1, which is applied to a battery. The application unit is configured such that when the conductivity is expressed by σ, the magnetic permeability is expressed by μ, and the thickness is expressed by d, the first is expressed by 1 / (πσμd ² ). The battery inspection apparatus according to claim 2, wherein the external voltage obtained by superimposing the AC voltage corresponding to the second frequency lower than one frequency on the DC voltage is applied to the battery. The said battery test | inspection apparatus is further provided with the production | generation part which produces | generates the image which shows the magnetic field distribution or electric current distribution inside the said battery based on the magnetic field measured by the said measurement part. The battery inspection apparatus described in 1. The battery inspection apparatus according to claim 4, wherein the battery inspection apparatus further includes a display unit that displays the image generated by the generation unit. The application unit superimposes the AC voltage on the DC voltage in a plurality of periods by intermittently applying the external voltage obtained by superimposing the AC voltage on the DC voltage in the charge / discharge process of the battery. Applying the external voltage to the battery,
The battery inspection apparatus according to claim 1, wherein the measurement unit measures a magnetic field outside the battery in each of the plurality of periods. The battery inspection apparatus further generates a video including a plurality of images each indicating a magnetic field distribution or a current distribution inside the battery, based on the magnetic fields measured in the plurality of periods by the measurement unit. The battery inspection apparatus according to claim 6, further comprising a generation unit. The battery inspection apparatus according to claim 7, wherein the battery inspection apparatus further includes a display unit that displays the video generated by the generation unit. A battery inspection method for inspecting a battery,
In the charging and discharging process of the battery, an application step of applying an external voltage obtained by superimposing an AC voltage on a DC voltage for balancing the output voltage of the battery to the battery;
Measuring the magnetic field outside the battery in a state where the external voltage obtained by superimposing the AC voltage on the DC voltage is applied to the battery,
The battery includes a shielding unit that prevents a current inside the battery from generating a magnetic field outside the battery,
In the applying step, the external voltage obtained by superimposing the alternating voltage corresponding to the second frequency lower than the first frequency determined based on the characteristic of the shielding portion on the direct current voltage is applied to the battery.

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