JP2004303756A - Electric storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain the performance of a capacitor and to improve a lifetime. <P>SOLUTION: A cell body 11 includes a plurality of capacitor cells 10 contained together with an electrolyte in a cell container 12, an electrolyte tank 23 for storing the electrolyte, a liquid level sensor 18 for detecting the level of the electrolyte in each cell container 12, a communicating passage 15 formed to guide the electrolyte of the electrolyte tank 23 to the cell container 12, and a valve means 17 for opening and closing the communicating passage 15 at each cell container 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power storage device for an electric double layer capacitor.
[0002]
[Prior art]
2. Description of the Related Art In recent years, attention has been focused on an application technique of an electric double layer capacitor (electric double layer capacitor) that can be rapidly charged and has a long charge / discharge cycle life as various power storage devices (e.g., a driving power supply of an electric vehicle).
[0003]
An electric double layer capacitor is a capacitor cell in which a certain number of positive and negative electrodes are alternately stacked with a separator interposed therebetween, and the stacked body is immersed in an electrolytic solution and housed in a container together with the electrolytic solution. At the same time, a plurality of capacitor cells are used for practical use (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-11-317334
[Problems to be solved by the invention]
In such an electric double layer capacitor, there has been a problem that the electrolyte solution is deteriorated and consumed while being used for a long time, resulting in a decrease in performance and a shortened life.
[0006]
An object of the present invention is to solve such a problem.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, a plurality of capacitor cells each including a cell body in which a fixed number of positive and negative electrode bodies are alternately stacked with a separator interposed therebetween and accommodated in a cell container together with an electrolytic solution, And a liquid level sensor for detecting the level of the electrolyte in each cell container, and a communication passage for guiding the electrolyte in the electrolyte tank to each cell container is formed. Is provided with valve means for opening and closing the communication passage.
[0008]
According to a second aspect, in the first aspect, a pump for pumping the electrolytic solution in the electrolytic solution tank is provided, and a determination means for measuring an internal resistance of the capacitor cell to determine a deterioration state of the capacitor cell, There is provided control means for controlling the pump and the valve means according to the determination result of the deterioration state and the detection value of the liquid level sensor.
[0009]
In a third aspect based on the second aspect, the measured value of the internal resistance of the capacitor cell is corrected according to the temperature.
[0010]
【The invention's effect】
In the first aspect, when the electrolyte of the capacitor cell is deteriorated or consumed, the electrolyte is injected from the electrolyte tank into the corresponding capacitor cell, so that the performance of the capacitor cell can be maintained and the life can be improved. .
[0011]
In the second invention, the electrolytic solution can be appropriately injected into the capacitor cell via the pump in accordance with the deterioration state of the capacitor cell and the amount of the electrolytic solution, so that the performance of the capacitor cell can be maintained and the life can be improved. it can.
[0012]
According to the third aspect, the deterioration state of the capacitor cell can be accurately determined.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a configuration diagram of a power storage device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of an electric double layer capacitor cell 10.
[0015]
In the capacitor cell 10, a cell body (laminated body) 11 is housed in a cell container 12 having a predetermined structure together with an electrolytic solution.
[0016]
The cell body 11 is formed by alternately stacking a certain number of positive and negative electrodes with a separator interposed therebetween, with the lead 12a of the positive electrode bonded to the terminal 13a and the lead 12b of the negative electrode bonded to the terminal 13b. Is done. These terminals 13 a and 13 b are arranged so as to penetrate the upper wall portion 14 of the cell container 12.
[0017]
At a predetermined portion of the upper wall portion 14 of the cell container 12, a passage opening 16 that opens to the communication passage 15 is opened, and an electromagnetic valve 17 that opens and closes the passage opening 16 is provided. The solenoid valve 17 is provided with a liquid level sensor 18 for detecting the level of the electrolytic solution in the cell container 12.
[0018]
In this case, when the solenoid valve 17 is driven (when energized), the valve body 20 is retracted from the seating portion on the cell container 12 side against the spring 21 and opened, and when not driven (when not energized). The body 20 is forwardly seated on the seating portion on the side of the cell container 12 by the biasing force of the spring 21 to close the valve, and is formed on the front surface of the valve body 20 to receive the pressure in the cell container 12.
[0019]
In addition, a gas release valve 22 (safety valve) is provided at a central portion of the upper wall portion 14 of the cell container 12 to release gas generated by decomposition of the electrolytic solution or solvent.
[0020]
On the other hand, an electrolytic solution tank 23 for storing an electrolytic solution is provided, and the electrolytic solution tank 23 is connected to the passage opening 16 of the cell container 12 of each capacitor cell 10 via the communication passage 15. In the communication passage 15, branch passages 24 branching from the passage 15 are connected to respective passage openings 16.
[0021]
The electrolyte tank 23 is provided with a pump 25 for pumping the electrolyte to each cell container 12 through the communication passage 15.
[0022]
Then, a control device 26 for determining the deterioration state of each capacitor cell 10 and controlling the driving of the pump 25 and the opening and closing of the solenoid valve 17 of each capacitor cell 10 is provided.
[0023]
The control device 26 calculates the internal resistance value of each capacitor cell 10 from the voltage value and the current value of each capacitor cell 10, and determines the deterioration state of each capacitor cell 10 from the internal resistance value. In this case, since the internal resistance value of the capacitor cell 10 changes depending on the temperature, a temperature sensor 27 for detecting the temperature state of a predetermined capacitor cell 10 is provided, and the internal resistance value is corrected based on the temperature state. Controlling the operation of the pump 25 and the opening and closing of the solenoid valve 17 of each capacitor cell 10 in accordance with the determination of the deterioration state and the detection value of the liquid level sensor 18 for detecting the level of the electrolytic solution in the cell container 12 The control contents of the control device 26 will be described with reference to the flowchart of FIG.
[0024]
First, in step S1, the internal resistance value α of each capacitor cell 10 is calculated from the voltage value V and the current value I of each capacitor cell 10. Each internal resistance value α is corrected according to the temperature detected by the temperature sensor 27.
[0025]
In step S2, it is determined whether each internal resistance value α is larger than a reference value.
[0026]
If there is a value larger than the reference value, it is determined that the battery is in a deteriorated state, and in step S3, it is determined whether the detection value (the amount of the electrolyte) of the liquid level sensor 18 of the corresponding capacitor cell 10 is larger than the reference value.
[0027]
If the value detected by the liquid level sensor 18 is smaller than the reference value, the process proceeds to step S4 and subsequent steps.
[0028]
In step S4, the solenoid valve 17 of the passage opening 16 connected to the communication passage 15 of the corresponding capacitor cell 10 is opened.
[0029]
In steps S5 and S6, the pump 25 of the electrolyte tank 23 is operated to pump the electrolyte through the communication passage 15 and inject the electrolyte into the cell container 12 of the corresponding capacitor cell 10.
[0030]
In step S7, when the detected value of the liquid level sensor 18 of the corresponding capacitor cell 10 becomes larger than the reference value, the pump 25 is stopped, the electromagnetic valve 17 that has been opened is closed, and the process ends.
[0031]
With such a configuration, when the electrolyte of the capacitor cell 10 is deteriorated and consumed while being used for a long time, the corresponding capacitor is determined according to the internal resistance value of the capacitor cell 10 and the detection value of the liquid level sensor 18. The electrolyte in the electrolyte tank 23 is injected into the cell 10.
[0032]
For this reason, it is possible to prevent the performance of the capacitor cell 10 from deteriorating, maintain good performance, improve the life of the capacitor cell 10, and secure high reliability of the power storage device. .
[0033]
In the embodiment, the pump 25 is used to inject the electrolytic solution. However, the electrolytic solution tank 23 is installed at a high position to inject the electrolytic solution, or the inside of the electrolytic solution tank 23 is pressurized. Alternatively, the electrolyte may be injected. Further, the gas generated by the decomposition of the solution or the solvent of the electrolytic solution may be configured to operate the solenoid valve 17 of the capacitor cell 10 to release the gas by the gas pressure.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a first embodiment.
FIG. 2 is a sectional view of an electric double layer capacitor cell.
FIG. 3 is a flowchart showing control contents.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Capacitor cell 11 Cell main body 12 Cell container 13a, 13b Terminal 15 Communication passage 16 Passage opening 17 Solenoid valve 18 Liquid level sensor 23 Electrolyte tank 25 Pump 26 Control device 27 Temperature sensor

Claims (3)

While providing a plurality of capacitor cells each containing a certain number of positive electrode bodies and negative electrode bodies alternately stacked with a separator interposed therebetween in a cell container together with an electrolytic solution,
Provide an electrolyte tank for storing electrolyte,
With a liquid level sensor that detects the level of the electrolyte in each cell container,
Forming a communication passage that leads the electrolyte in the electrolyte tank to each cell container,
A power storage device provided with valve means for opening and closing a communication passage for each cell container. With a pump that pumps the electrolyte in the electrolyte tank,
Determining means for measuring the internal resistance of the capacitor cell to determine the deterioration state of the capacitor cell;
The power storage device according to claim 1, further comprising control means for controlling the pump and the valve means in accordance with a result of determining the deterioration state of the capacitor cell and a value detected by the liquid level sensor. The power storage device according to claim 2, wherein the measured value of the internal resistance of the capacitor cell is corrected according to the temperature.

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