Detection device, management apparatus, and detection method
A detection device includes a detector and a controller. The detector has at least one resonator circuit applying at least one specific frequency vibration to a lithium-ion secondary battery, measures an attenuation characteristic of at least one resonant current, and outputs the attenuation characteristic as a detection signal. The controller detects lithium deposition and/or presence of foreign metal inside the lithium-ion secondary battery by using the detection signal of the attenuation characteristic acquired from the detector.
1 . A detection device that detects a state of a lithium-ion secondary battery, the detection device comprising:
a detector having at least one resonator circuit that applies at least one specific frequency vibration to the lithium-ion secondary battery and a drive circuit that drives the at least one resonator circuit, the detector measuring an attenuation characteristic of at least one resonant current of the at least one resonator circuit driven by the drive circuit, and outputting the measured attenuation characteristic as a detection signal, wherein
one end of the at least one resonator circuit is connected to one pole of the lithium-ion secondary battery and another end of the at least one resonator circuit is connected to another pole of the lithium-ion secondary battery; and
a controller that detects lithium deposition and/or presence of foreign metal inside the lithium-ion secondary battery by using the detection signal output from the detector.
2 . The detection device according to claim 1 , wherein the controller detects the lithium deposition and/or the presence of the foreign metal by estimating a battery resistance using voltage values at a plurality of time points as the attenuation characteristic of the at least one resonant current.
3 . A detection device that detects a state of a lithium-ion secondary battery, the detection device comprising:
a detector having at least one resonator circuit that applies at least one specific frequency vibration to the lithium-ion secondary battery, the detector measuring an attenuation characteristic of at least one resonant current and outputting the attenuation characteristic as a detection signal; and
a controller that detects lithium deposition and/or presence of foreign metal inside the lithium-ion secondary battery by using the detection signal output from the detector, wherein
the detector includes the at least one resonator circuit, a wave sensor that rectifies a signal output from the at least one resonator circuit and outputs the signal as the detection signal, and a drive circuit that drives the at least one resonator circuit.
4 . The detection device according to claim 3 , wherein the detector includes a closed circuit, the wave sensor, and the drive circuit, the closed circuit being constituted of the at least one resonator circuit including a pickup-coil-equipped first inductor parallel-connected to the lithium-ion secondary battery, a resonant capacitor series-connected to the first inductor, and a semiconductor switch series-connected to the first inductor, the wave sensor having a pickup-coil-equipped second inductor that detects a resonant current flowing through the first inductor, a rectifier circuit constituted of a diode bridge connected to the second inductor, and a filter that includes a capacitor and a resistor, filters a rectified waveform, and outputs the detection signal, the drive circuit turning on the semiconductor switch via a drive capacitor parallel-connected to the lithium-ion secondary battery and via a buffer supplied with electric power from the drive capacitor.
5 . A detection device that detects a state of a lithium-ion secondary battery, the detection device comprising:
a detector having at least one resonator circuit that applies at least one specific frequency vibration to the lithium-ion secondary battery, the detector measuring an attenuation characteristic of at least one resonant current and outputting the attenuation characteristic as a detection signal; and
a controller that detects lithium deposition and/or presence of foreign metal inside the lithium-ion secondary battery by using the detection signal output from the detector, wherein
the controller includes a logic calculator that has at least one sample-and-hold circuit and that calculates the detection signal output from a filter in the detector, an isolator that has a series capacitor and that outputs a drive signal to a drive circuit, and a main calculator that outputs a drive signal to the isolator and that receives the detection signal from the logic calculator.
6 . The detection device according to claim 1 , wherein the controller detects the lithium deposition and/or the presence of the foreign metal inside the lithium-ion secondary battery based on a decrease in a real part of impedance when the frequency vibration applied by the resonator circuit is in a range of 5 MHz or lower.
7 . The detection device according to claim 1 , wherein the controller detects a coating formed on an electrode based on an increase in a real part of impedance when the frequency vibration applied by the resonator circuit is in a range of 10 MHz or higher.
8 . The detection device according to claim 1 ,
wherein the lithium-ion secondary battery includes a plurality of parallel-connected or series-connected single cells connected to the detector, and
wherein the controller is connected to a plurality of the detectors and detects the lithium deposition and/or the presence of the foreign metal inside any one of the single cells.
9 . The detection device according to claim 1 , wherein the detector has identification information for identifying the connected lithium-ion secondary battery and outputs the detection signal and the identification information in correspondence with each other.
10 . The detection device according to claim 1 ,
wherein the lithium-ion secondary battery is series-connected to an irreversible switch, and
wherein, when the controller determines that the lithium-ion secondary battery is in an abnormal state, the controller turns off the irreversible switch.
11 . A management apparatus that manages the lithium-ion secondary battery based on information acquired from the detection device according to claim 1 , the management apparatus comprising:
a management unit that uses a detection result, output from the controller, about the lithium deposition inside the lithium-ion secondary battery to utilize the lithium-ion secondary battery while limiting usage thereof based on a remaining volume of active lithium.
12 . A management apparatus that manages the lithium-ion secondary battery based on information acquired from the detection device according to claim 1 , the management apparatus comprising:
a management unit that uses a detection result, output from the controller, about the lithium deposition inside the lithium-ion secondary battery to quantify a residual value, including a remaining usage time, of the lithium-ion secondary battery based on a remaining volume of active lithium.
13 . A management apparatus that manages the lithium-ion secondary battery based on information acquired from the detection device according to claim 1 , the management apparatus comprising:
a management unit that calculates a distribution value by using a detection result, output from the controller, about the lithium deposition inside the lithium-ion secondary battery, and outputs the calculated distribution value.
14 . The detection device according to claim 1 , wherein the detector includes the at least one resonator circuit, a wave sensor that rectifies a signal output from the at least one resonator circuit and outputs the signal as the detection signal, and the drive circuit that drives the at least one resonator circuit.
15 . The detection device according to claim 14 , wherein the detector includes a closed circuit, the wave sensor, and the drive circuit, the closed circuit being constituted of the at least one resonator circuit including a pickup-coil-equipped first inductor parallel-connected to the lithium-ion secondary battery, a resonant capacitor series-connected to the first inductor, and a semiconductor switch series-connected to the first inductor, the wave sensor having a pickup-coil-equipped second inductor that detects a resonant current flowing through the first inductor, a rectifier circuit constituted of a diode bridge connected to the second inductor, and a filter that includes a capacitor and a resistor, filters a rectified waveform, and outputs the detection signal, the drive circuit turning on the semiconductor switch via a drive capacitor parallel-connected to the lithium-ion secondary battery and via a buffer supplied with electric power from the drive capacitor.
16 . The detection device according to claim 1 , wherein the controller includes a logic calculator that has at least one sample-and-hold circuit and that calculates the detection signal output from a filter in the detector, an isolator that has a series capacitor and that outputs a drive signal to the drive circuit, and a main calculator that outputs a drive signal to the isolator and that receives the detection signal from the logic calculator.
17 . A detection method for detecting a state of a lithium-ion secondary battery, the detection method comprising:
an output step for applying at least one specific frequency vibration to the lithium-ion secondary battery by at least one resonator circuit, measuring an attenuation characteristic of at least one resonant current of the at least one resonator circuit driven by a drive circuit while one end of the at least one resonator circuit is connected to one pole of the lithium-ion secondary battery and another end of the at least one resonator circuit is connected to another pole of the lithium-ion secondary battery, and outputting the measured attenuation characteristic as a detection signal; and
a detection step for detecting lithium deposition and/or presence of foreign metal inside the lithium-ion secondary battery by using the detection signal outputted in the output step.
18 . The detection method according to claim 17 , wherein the detector includes the at least one resonator circuit, a wave sensor that rectifies a signal output from the at least one resonator circuit and outputs the signal as the detection signal, and the drive circuit that drives the at least one resonator circuit.
19 . The detection method according to claim 18 , wherein the detector includes a closed circuit, the wave sensor, and the drive circuit, the closed circuit being constituted of the at least one resonator circuit including a pickup-coil-equipped first inductor parallel-connected to the lithium-ion secondary battery, a resonant capacitor series-connected to the first inductor, and a semiconductor switch series-connected to the first inductor, the wave sensor having a pickup-coil-equipped second inductor that detects a resonant current flowing through the first inductor, a rectifier circuit constituted of a diode bridge connected to the second inductor, and a filter that includes a capacitor and a resistor, filters a rectified waveform, and outputs the detection signal, the drive circuit turning on the semiconductor switch via a drive capacitor parallel-connected to the lithium-ion secondary battery and via a buffer supplied with electric power from the drive capacitor.
20 . The detection method according to claim 17 , wherein the detection step is performed by a controller that includes: a logic calculator that has at least one sample-and-hold circuit and that calculates the detection signal output from a filter in the detector, an isolator that has a series capacitor and that outputs a drive signal to the drive circuit, and a main calculator that outputs a drive signal to the isolator and that receives the detection signal from the logic calculator.