JP3927139B2 - Power storage device - Google Patents

Description

[0001]
BACKGROUND 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 application technologies of electric double layer capacitors (electric double layer capacitors) that can be rapidly charged and have a long charge / discharge cycle life as various power storage devices (such as drive power sources for electric vehicles).
[0003]
An electric double layer capacitor is a capacitor cell in which a certain number of positive and negative electrode bodies are alternately stacked with a separator interposed therebetween, and these stacked bodies are immersed in an electrolytic solution and accommodated in a container together with the electrolytic solution. Is done.
[0004]
Such an electric double layer capacitor is used in combination with a plurality of capacitor cells depending on the required power, but the electrolyte solution and solvent may decompose and generate gas during long-term use. Therefore, a safety valve for venting gas is provided in each capacitor cell container, each capacitor cell container is connected to a buffer container, and a gas adsorbent is placed in the buffer container, or a safety valve is provided in the buffer container. (For example, refer to Patent Document 1).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-317334
[Problems to be solved by the invention]
However, providing a buffer container or using a gas adsorbent requires space and maintenance of adsorbent replacement. In addition, since the safety valve cannot be opened at an unnecessarily low pressure, for example, when a container made of a material with low rigidity is used for the cell, there is a concern that the container may be deformed before the safety valve is activated, and the pressure is applied to the container. If the retained gas remains, it will affect the performance and life of the cell.
[0007]
An object of the present invention is to solve such problems.
[0008]
[Means for Solving the Problems]
The first invention is a cell in the energy storage device comprising a plurality of capacitor cells, capacitors, the cell body were alternately laminated by interposing the separator between them a certain number of positive electrode and negative electrode body together with an electrolyte A pressurizing unit that is housed in a container and arranged as a unit to apply a predetermined surface pressure in a direction in which the plurality of capacitor cells are arranged; a pressurization sensor that detects the pressurizing force of the pressurizing unit; One provided with a gas discharge pipe branchingly connected to the cell container of each capacitor cell, valve means for opening and closing the gas discharge port of the gas discharge pipe, and control means for controlling the valve means in accordance with the detection value of the pressure sensor Each gas outlet pipe connected to the inside of the cell container of the gas exhaust pipe is provided with a gas permeable membrane that exhausts gas but does not allow electrolyte solution to pass through .
[0010]
【The invention's effect】
In the first invention, the influence of the generated gas on the capacitor cell can be sufficiently eliminated, and the performance and life of the capacitor cell can be improved.
[0011]
In this case , without providing a pressure sensor for detecting the pressure in the gas discharge pipe, it is possible to sufficiently eliminate the influence of the generated gas on the capacitor cell. On the other hand, by applying a predetermined surface pressure, Can be adhered uniformly, and the internal resistance performance is greatly improved. In addition, the electrolyte does not excessively enter the laminate, while the electrolyte inside the capacitor cell does not pass through the gas permeable membrane during gas discharge , ensuring stable performance of each capacitor cell, Therefore, the performance and life of the capacitor cell can be further improved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
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.
[0014]
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.
[0015]
The cell body 11 is formed by alternately stacking a certain number of positive electrode bodies and negative electrode bodies with separators interposed therebetween, and the lead portion 12a of the positive electrode body is joined to the terminal 13a and the lead portion 12b of the negative electrode body is joined to the terminal 13b. Is done. These terminals 13a and 13b are disposed through the upper wall portion 14 of the cell container 12.
[0016]
A lead-out pipe 15 connected to the inside of the cell container 12 is connected to a predetermined portion of the upper wall portion 14 of the cell container 12.
[0017]
The lead-out pipe 15 of the cell container 12 of each capacitor cell 10 is connected to the gas discharge pipe 16. The lead-out pipe 15 of the cell container 12 is provided with a gas permeable membrane 39 that discharges gas but does not allow electrolyte to pass through, so that the electrolyte in the cell does not come out when the gas is discharged.
[0018]
The gas exhaust pipe 16 is provided with an opening portion (gas exhaust port 17) only at one end, and an electromagnetic valve 18 for opening and closing the gas exhaust port 17 is disposed at this end.
[0019]
The electromagnetic valve 18 is provided with a pressure sensor 20 that detects the pressure in the gas discharge pipe 16.
[0020]
The detection signal of the pressure sensor 20 is sent to the control device 21, and the control device 21 controls the opening and closing of the electromagnetic valve 18 based on the detection signal.
[0021]
The control contents of the control device 21 will be described with reference to the flowchart of FIG. 3. First, in step S 1, the pressure in the gas exhaust pipe 16 is viewed from the detection signal of the pressure sensor 20.
[0022]
In step S2, it is determined whether or not the pressure in the gas discharge pipe 16 is larger than a predetermined low pressure reference value (pressure slightly higher than atmospheric pressure).
[0023]
If larger than the reference value, the process proceeds to step S3, and the solenoid valve 17 is opened.
[0024]
With this configuration, when the electrolyte solution or solvent in the capacitor cell 10 is decomposed and gas is generated, the gas passes through the outlet pipe 15 and enters the gas discharge pipe 16. When the pressure in the gas exhaust pipe 16 is detected and the pressure in the gas exhaust pipe 16 exceeds a reference value of a predetermined low pressure, the gas exhaust port 17 is opened by the electromagnetic valve 18.
[0025]
For this reason, the gas is quickly discharged from the gas discharge pipe 16 to the outside, and the pressure in the capacitor cell 10, the lead-out pipe 15, and the gas discharge pipe 16 is kept at a predetermined low pressure or lower.
[0026]
Therefore, for example, even when the cell container 12 made of a material having low rigidity is used for the capacitor cell 10, the cell container 12 can be prevented from being deformed by the pressure of the generated gas.
[0027]
Since the gas pressure in the capacitor cell 10, the lead-out pipe 15, and the gas discharge pipe 16 can be kept below a predetermined low pressure, the influence of the generated gas on the capacitor cell 10 can be sufficiently eliminated, and the performance and life of the capacitor cell 10 can be eliminated. Can be improved.
[0028]
Due to the structure in which the electromagnetic valve 18 is disposed in the gas discharge pipe 16, no space is required and the maintenance is excellent.
[0029]
FIG. 4 shows another embodiment of the present invention.
[0030]
The electric double layer capacitor is used in combination with a plurality of capacitor cells 10 according to required power. In this case, a plurality of capacitor cells 10 are arranged as a unit, and a pressurizing mechanism 30 for applying a predetermined surface pressure in the arrangement direction is provided. In addition, a pressure sensor 31 for detecting the pressure applied by the pressure mechanism 30 is provided, and the pressure sensor 31 also serves as the pressure sensor 20.
[0031]
A plurality of capacitor cells 10 are arranged and accommodated in a box-type case 32, and a predetermined surface pressure is applied to the capacitor cells 10 in the arrangement direction by a pressurizing mechanism 30 provided in the case 32.
[0032]
The pressure mechanism 30 is a pressure piston that abuts against the surface of the push bolt 33, the push plate 34, and the capacitor cell 10 in the foremost row and transmits the push force of the push bolt 33 to the arrangement direction of the capacitor cell 10 via the spring 35. 36, a lock nut 37, a stopper 38, and the like. The push bolts 33 are tightened based on the detection value of the pressure sensor 31 provided on the other side of the case 32, and a predetermined surface pressure is applied to each capacitor cell 10. Add
[0033]
The detection value (detection signal) of the pressure sensor 31 is sent to the control device 21.
[0034]
While the control device 21 can confirm the pressurizing force of the pressurizing mechanism 30, the control device 21 determines that the detected value of the pressurizing sensor 31 is larger than a reference value (including the pressurizing force of the pressurizing mechanism 30). Control is made so that the electromagnetic valve 18 of the gas discharge pipe 16 is opened.
[0035]
Other configurations may be the same as those in the above embodiment except for the pressure sensor 20.
[0036]
In this way, the influence of the generated gas on the capacitor cell 10 can be sufficiently eliminated without providing the pressure sensor 20 for detecting the pressure in the gas discharge pipe 16, while a predetermined surface pressure is applied. As a result, the stacked body (cell body 11) inside each capacitor cell 10 can be uniformly adhered, and the internal resistance performance is greatly improved. In addition, the electrolyte does not excessively enter the laminated body, and stable performance of each capacitor cell 10 can be ensured. Therefore, the performance and life of the capacitor cell 10 can be further improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a first embodiment.
FIG. 2 is a cross-sectional view of an electric double layer capacitor cell.
FIG. 3 is a flowchart showing control contents.
FIG. 4 is a configuration diagram of a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Capacitor cell 11 Cell main body 12 Cell container 13a, 13b Terminal 15 Outlet pipe 16 Gas exhaust pipe 17 Gas exhaust port 18 Electromagnetic valve 20 Pressure sensor 21 Control apparatus 30 Pressurization mechanism 31 Pressurization sensor 32 Case

Claims (1)

In a power storage device composed of a plurality of capacitor cells, a capacitor includes a cell body in which a certain number of positive and negative electrode bodies are alternately stacked with a separator interposed therebetween, and is accommodated in a cell container together with an electrolyte. A pressurizing means for arranging a plurality of capacitor cells as a unit and applying a predetermined surface pressure in the arrangement direction, a pressurizing sensor for detecting the pressurizing force of the pressurizing means, and a cell container for each capacitor cell A gas discharge pipe branched and connected to the gas discharge pipe, a valve means for opening and closing a gas discharge port of the gas discharge pipe, and a control means for controlling the valve means in accordance with a detection value of the pressure sensor. A power storage device, characterized in that a gas permeable membrane that discharges gas but does not allow electrolyte to pass through is provided in each outlet pipe connected to the inside of the container .

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