JP2012150033A - Resistance measuring device and resistance measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resistance measuring device and a resistance measuring method for accurately detecting resistance along a vertical direction to a surface of a resistance detection body.SOLUTION: A resistance measuring device 1 comprises: first current applying means 5 for applying a first current to first portions where resistance along a vertical direction to a surface of a resistance detection body 2 is to be measured; second current applying means 6 for applying a second current to second portions each set to surround the first portion and closer to an outer periphery than the first portion so as to make a potential difference between the first portions and the second portions along an in-plane direction of the resistance detection body 2 substantially zero; and first voltage detecting means 7 for detecting a first voltage obtained between the first portions in applying the first current and the second current.

Description

  The present invention relates to a resistance measuring device and a resistance measuring method.

  In a battery having a high resistance in the in-plane direction of the current collector, such as a battery using a resin current collector, if the resistance in the in-plane direction of the electrode layer laminated on the current collector varies, Voltage distribution will occur. Therefore, in a battery having a high resistance in the in-plane direction of the current collector, it is necessary to reduce the in-plane resistance of the electrode layer. For that purpose, it is important to grasp the resistance distribution (local resistance) of the electrode layer.

  Conventionally, as an apparatus for detecting battery characteristics, there is one disclosed in Patent Document 1. In Patent Document 1, an alternating current is applied to a battery, and an internal resistance is detected by an alternating voltage signal generated between the terminals of the battery.

JP-A-9-281202

  However, the apparatus according to the present invention has a problem that the total resistance, that is, the average value of the resistance can be measured, but the local resistance cannot be measured.

  The present invention has been invented to solve such problems, and aims to accurately measure the local resistance of a measurement point.

  A resistance measuring device according to an aspect of the present invention includes a first current applying unit that applies a first current to a first part that measures resistance in a direction perpendicular to a resistance detector, and an outer peripheral side of the first part. A second current applying means for applying a second current at which the potential difference between the first part and the second part in the in-plane direction of the resistance detector is substantially zero to a second part provided so as to surround the first part; Is provided. The resistance measuring device further includes first voltage detecting means for detecting a first voltage between the first portions when the first current and the second current are applied.

  According to this aspect, since the voltage in the direction perpendicular to the surface of the resistance detector is detected in a state where no current flows in the in-plane direction of the resistance detector, the local resistance in the direction perpendicular to the surface of the resistance detector is accurately determined. Can be calculated.

It is a schematic block diagram which shows the resistance measuring apparatus of 1st Embodiment. It is a figure which shows arrangement | positioning of the probe of 1st Embodiment. It is a figure explaining the flow of an electric current when not using a 1st embodiment. It is a figure explaining the flow of the electric current at the time of using 1st Embodiment. It is a flowchart explaining the calculation method of the internal resistance of 1st Embodiment. It is a figure which shows the battery model used in 1st Embodiment. It is a figure which shows the relationship between the applied current and voltage in the battery model used in 1st Embodiment. It is a schematic block diagram which shows the resistance measuring apparatus of 2nd Embodiment. It is a flowchart explaining the calculation method of the internal resistance of 2nd Embodiment. It is a schematic block diagram which shows the resistance measuring apparatus of 3rd Embodiment. It is a flowchart explaining the calculation method of the internal resistance of 3rd Embodiment. It is a figure which shows the modification of the probe in this embodiment.

  A resistance measuring apparatus 1 according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a resistance measuring apparatus 1 of the present embodiment. The resistance measuring device 1 is a device that measures the internal resistance in the direction perpendicular to the surface of the resistance detector. Here, the battery 2 using a resin current collector as a resistance detector will be described. However, the present invention is not limited to this, and any battery having a large variation in resistance value in the in-plane direction of the resistance detector may be used.

  The resin current collector 3 is, for example, a current collector of a solid electrolyte type secondary battery (hereinafter referred to as a battery) 2, and is a current collector made of a conductive polymer material, or a conductive polymer material, It is a current collector composed of a resin obtained by adding a conductive filler to a non-conductive polymer material. Examples of the conductive polymer material include polyaniline and polypyrrole. Examples of the non-conductive polymer material include polyethylene and polypropylene. The conductive filler is, for example, a metal, conductive carbon, or the like.

  The resistance measuring device 1 includes a pair of probes 4, a first current source 5, a second current source 6, and a first voltmeter 7.

  The probe 4 will be described with reference to FIG. FIG. 2 is a diagram showing the arrangement of the probes 4 in the battery 2. In FIG. 2, some hidden lines are shown by broken lines for the sake of explanation.

  The probe 4 includes a first electrode 8 and a second electrode 9.

  The first electrode 8 is formed in a columnar shape, and the second electrode 9 is formed in a cylindrical shape. The second electrode 9 is coaxial with the first electrode 8 and is provided so that the inner peripheral wall of the second electrode 9 and the outer peripheral wall of the first electrode 8 face each other. A space is formed between the inner peripheral wall of the second electrode 9 and the outer peripheral wall of the first electrode 8.

  The first electrode 8 is in contact with the resistance measurement portions 30 a and 30 b arranged in the direction perpendicular to the surface of the battery 2. The second electrode 9 is on the outer peripheral side of the resistance measurement parts 30a, 30b, and comes into contact with surrounding parts (second parts) 31a, 31b provided so as to surround the resistance measurement parts 30a, 30b. The pair of probes 4 are arranged so that the first electrodes 8 face each other and the second electrodes 9 face each other across the battery 2.

  The first current source 5 is connected to the first electrode 8, and applies a current to the resistance measurement portions 30 a and 30 b via the first electrode 8. The second current source 6 is connected to the second electrode 9 and applies a current to the surrounding portions 31 a and 31 b via the second electrode 9. The first current source 5 and the second current source 6 may be a DC power source or an AC power source.

  The first voltmeter 7 measures the voltage between the resistance measurement portions 30 a and 30 b via the first electrode 8.

  Next, the current flow when the internal resistance of the battery 2 is detected using the resistance measuring apparatus 1 of the present embodiment will be described with reference to FIGS. Here, the battery 2 will be described using a model in which a plurality of resistors are connected. FIG. 3 is a diagram for explaining the flow of current when the resistance measurement apparatus 1 of the present embodiment is not used. FIG. 4 is a diagram for explaining a current flow when the resistance measuring apparatus 1 of the present embodiment is used.

  When the resistance measuring apparatus 1 of the present embodiment is not used, the electrode of the probe is connected to the resistance measuring portions 30a and 30b of the battery, and when a current is applied, the resin current collector is directed in the direction perpendicular to the surface and in the in-plane direction. Current flows. Therefore, when the voltage between the resistance measurement parts 30a and 30b is detected and the internal resistance is calculated based on the detected voltage, the internal resistance including the resistance around the resistance measurement parts 30a and 30b is calculated.

  On the other hand, when the resistance measuring apparatus 1 of the present embodiment is used, a current is applied from the first current source 5 to the resistance measuring portions 30 a and 30 b through the first electrode 8, and the second electrode 9 is used as the second electrode 9. 2 Current is applied from the current source 6 to the surrounding parts 31a and 31b. When the current value applied by the second current source 6 becomes a predetermined value, the potential difference between the resistance measurement parts 30a, 30b and the surrounding parts 31a, 31b becomes zero. That is, the potential difference in the in-plane direction becomes zero. In such a case, as shown in FIG. 4, the current is cut off between the resistance measurement parts 30 a and 30 b and the surrounding parts 31 a and 31 b and is applied by the first current source 5. The current flows only in the direction perpendicular to the surface of the resin current collector 3. In this state, the first voltmeter 7 detects the voltage between the resistance measurement portions 30a and 30b, and calculates the resistance using the detected voltage and the current applied by the first current source 5, thereby measuring the resistance. The internal resistance between the parts 30a and 30b can be accurately calculated.

  Next, a method for calculating the internal resistance between the resistance measurement portions 30a and 30b in the resistance measurement apparatus 1 of the present embodiment will be described with reference to the flowchart of FIG.

  In step S100, a current (second current) I2 with respect to the current (first current) I1 applied by the first current source 5 is calculated from a map prepared in advance. In the present embodiment, the current I is 20 (mA).

  Here, a method of calculating the current I2 will be described. The current I2 is a current at which the potential difference between the resistance measurement portions 30a and 30b and the surrounding portions 31a and 31b in the in-plane direction becomes substantially zero, and is calculated using the battery model of FIG. Substantially zero is a value that can be determined that there is no potential difference between the resistance measurement portions 30a, 30b and the surrounding portions 31a, 31b, and includes zero.

The battery model of FIG. 6 has an internal resistance of the battery 2 of 20 (Ω · cm ² ), a volume resistance of the resin current collector 3 of 0.5 (Ω · cm), and a thickness of the resin current collector 3 of 100 ( μm), a battery model in which the distance between the first electrode 8 and the second electrode 9 of the probe 4 of the resistance measuring device 1 is 0.5 (cm). Further, the current I1 applied by the first current source 5 is set to 20 (mA). The map of FIG. 7 shows the relationship between the current under these conditions and the voltage between the resistance measurement portions 30a and 30b and the surrounding portions 31a and 31b in the in-plane direction.

  As shown in FIG. 7, under the above conditions, there is a current I2 at which the potential difference between the resistance measurement portions 30a and 30b and the surrounding portions 31a and 31b in the in-plane direction with respect to the current I1 becomes zero.

  In this way, the current I2 with respect to the current I1 is calculated and prepared in advance as a map. In step S100, the current I2 with respect to the current I1 applied by the first current source 5 is calculated from the map.

  The current I1 is applied by the first current source 5, and the current I2 corresponding to the current I1 is applied by the second current source 6, so that the resistance measurement parts 30a, 30b and the surrounding parts 31a, 31b in the in-plane direction are between Is zero, and all of the current applied by the first current source 5 flows between the resistance measurement portions 30a and 30b in the direction perpendicular to the surface.

  In step S <b> 101, the first voltmeter 7 detects the voltage V <b> 0 of the battery 2 when an open circuit is applied without applying current from the first current source 5 and the second current source 6.

  In step S <b> 102, a current I <b> 1 of 20 (mA) is applied to the battery 2 through the first electrode 8 by the first current source 5. Further, the current I2 calculated in step S100 is applied to the battery 2 through the second electrode 9 by the second current source 6.

  In step S103, the first voltmeter 7 detects the voltage (first voltage) V1 between the resistance measuring units.

  In step S104, the application of the currents I1 and I2 by the first current source 5 and the second current source 6 is finished.

  In step S105, the internal resistance of the battery 2 between the resistance measurement sites is calculated. The internal resistance (R = (V0−V1) / I1) is calculated using the voltage V0 detected in step S101, the voltage V1 detected in step S103, and the current I1 applied by the first current source 5. The

  The effect of 1st Embodiment of this invention is demonstrated.

  A current I1 applied by the first current source 5 is applied by applying a current I2 at which the potential difference between the resistance measurement portions 30a, 30b and the surrounding portions 31a, 31b in the in-plane direction is zero by the second current source 6. Will flow only in the perpendicular direction. Then, the voltage between the resistance measurement parts 30 a and 30 b at that time is detected by the first voltmeter 7. As a result, the internal resistance between the resistance measurement portions 30a and 30b can be accurately calculated.

  By calculating the current I2 applied by the second current source 6 using a map prepared in advance, the configuration of the resistance measuring device can be simplified, and the measurement time of the internal resistance can be shortened.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a schematic configuration diagram of the resistance measuring apparatus of the present embodiment.

  The second embodiment will be described with a focus on differences from the first embodiment.

  The resistance measuring apparatus 10 of the present embodiment includes a second voltmeter 11 that detects a voltage between the first current source 5 and the second current source 6, the first current source 5, the second current source 6, and the first current source 5. The control unit 12 is connected to the voltmeter 7 and the second voltmeter 11, controls the current in the first current source 5 and the second current source 6, and calculates an internal resistance.

  The control unit 12 includes a CPU, a ROM, a RAM, and the like, and the control unit 12 exhibits its functions when the CPU reads and executes a program stored in the ROM.

  Next, a method for calculating the internal resistance between the resistance measurement portions 30a and 30b in the resistance measurement apparatus 10 of the present embodiment will be described with reference to the flowchart of FIG.

  In step S <b> 200, the first voltmeter 7 detects the voltage V <b> 0 of the battery 2 when an open circuit is applied without applying current from the first current source 5 and the second current source 6.

  In step S <b> 201, the current I <b> 1 is applied to the battery 2 through the first electrode 8 by the first current source 5. The current I1 is a preset current and is, for example, 20 mA as in the first embodiment.

  In step S <b> 202, a current is applied to the battery 2 through the second electrode 9 by the second current source 6. Here, the current applied by the second current source 6 is gradually increased from zero.

  In step S203, the voltage between the first current source 5 and the second current source 6 by the second voltmeter 11, that is, the voltage between the resistance measurement parts 30a, 30b and the surrounding parts 31a, 31b (second voltage). V2 is detected. Then, it is determined whether the voltage V2 has become substantially zero. When the voltage V2 becomes a predetermined voltage, the process proceeds to step S204.

  In step S204, the first voltmeter 7 detects the voltage V1 when the voltage V2 becomes a predetermined voltage.

  In step S205, application of current by the first current source 5 and the second current source 6 is terminated.

  In step S206, the internal resistance (R = (V0−V1) / I1) between the resistance measurement parts 30a and 30b is calculated.

  The effect of 2nd Embodiment of this invention is demonstrated.

  Resistance measurement is performed by changing the current applied by the second current source 6 and detecting a current at which the potential difference between the resistance measurement parts 30a, 30b and the surrounding parts 31a, 31b in the in-plane direction becomes substantially zero. The internal resistance between the parts 30a and 30b can be accurately calculated. Further, the internal resistance can be automatically calculated by controlling the currents of the first current source 5 and the second current source 6 by the control unit 12.

  Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 10 is a schematic configuration diagram of the resistance measuring device 15 of the present embodiment.

  The third embodiment will be described with a focus on differences from the second embodiment.

  The resistance measuring device 15 of this embodiment detects the internal resistance in the resin current collector 16.

  Next, a method for calculating the internal resistance between the resistance measurement portions 30a and 30b in the resistance measurement device 15 of the present embodiment will be described with reference to the flowchart of FIG.

  Steps S300 to S304 are the same as steps S201 to S205 of the second embodiment, and thus description thereof is omitted here. In this embodiment, not the battery but the internal resistance in the resin current collector 3 is detected.

  In step S305, the internal resistance (R = V1 / I1) between the resistance measurement parts 30a and 30b is calculated.

  The effect of the third embodiment of the present invention will be described.

  The internal resistance between the resistance measurement portions 30a and 30b of the resin current collector 16 can be accurately calculated. Further, the internal resistance between the resistance measurement portions 30a and 30b of the resin current collector 16 can be automatically calculated.

  In the above embodiment, the second electrode 9 is cylindrical, but the second electrode 17 may be divided along the circumferential direction as shown in FIG. As a result, the second electrode 17 and the resin current collector 16 can be reliably brought into contact with each other, the contact resistance between the second electrode 17 and the resin current collector 16 is prevented from becoming non-uniform, and the internal resistance is reduced. It can be calculated accurately.

  In the second embodiment and the third embodiment, the current is controlled by the control unit 12 and the internal resistance is calculated, but a part thereof may be performed manually.

  It goes without saying that the present invention is not limited to the above-described embodiments, and includes various modifications and improvements that can be made within the scope of the technical idea.

1, 10, 15 Resistance measuring device 2 Secondary battery (resistance detector)
5 First current source (first current applying means)
6 Second current source (second current applying means)
7 First voltmeter (first voltage detection means)
11 Second voltmeter (second voltage detection means)
16 Resin current collector (resistance detector)
12 Control unit (current control means, resistance calculation means)
30a, 30b Resistance measurement part (first part)
31a, 31b Surrounding part (second part)

Claims (5)

First current applying means for applying a first current to a first portion for measuring a resistance in a direction perpendicular to the surface of the resistance detector;
The potential difference between the first part and the second part in the in-plane direction of the resistance detector is substantially zero in a second part that is provided on the outer peripheral side of the first part and that surrounds the first part. Second current applying means for applying a second current to be
A resistance measuring apparatus comprising: a first voltage detecting unit configured to detect a first voltage between the first parts when the first current and the second current are applied.   The resistance measuring apparatus according to claim 1, wherein the second current is set based on a map set for the first current. Second voltage detection means for detecting a second voltage that is a potential difference between the first current application means and the second current application means;
Current control means for controlling the second current so that the second voltage becomes substantially zero when the first current is applied;
Resistance calculation means for calculating a resistance between the first portions based on the first voltage before flowing the first current and the first voltage when the second voltage becomes substantially zero; The resistance measuring apparatus according to claim 1, further comprising: Second voltage detection means for detecting a second voltage that is a potential difference between the first current application means and the second current application means;
Current control means for controlling the second current so that the second voltage becomes substantially zero when the first current is applied;
The resistance measuring device according to claim 1, further comprising: a resistance calculating unit that calculates a resistance between the first portions based on the first voltage when the second voltage becomes substantially zero. . Applying a first current to a first part for measuring a resistance in a direction perpendicular to the resistance detector;
Applying a second current to the second part that is provided on the outer peripheral side of the first part and surrounding the first part;
Detecting the first voltage when the first current and the second current are applied, and the potential difference between the first part and the second part is substantially zero;
A resistance measurement method comprising calculating a resistance between the first portions based on the first current and the first voltage.

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