JP3938063B2 - Storage element terminal structure and storage element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a terminal structure of a battery or capacitor power storage element and a power storage element using the terminal structure. More specifically, the present invention relates to a terminal structure of a power storage element that prevents an external short circuit and a power storage element using the terminal structure.
[0002]
[Prior art]
In recent years, due to the high energy density, batteries such as lithium ion secondary batteries and capacitors using the principle of electric double layers are widely used. Due to environmental problems and resource problems, such high-performance batteries and capacitor power storage elements are beginning to be used as power sources for driving automobiles. One example of such a storage element is disclosed in Japanese Patent Application Laid-Open No. 2002-231192. In general power storage elements, including those disclosed in Japanese Patent Application Laid-Open No. 2002-231192, an electrode body is inserted into a sealed case, and a positive electrode and a negative electrode are connected to the electrode body. Electric power is taken out by causing an electrode reaction between the positive electrode and the negative electrode.
[0003]
When attention is paid to such a terminal structure of the power storage element, as shown in FIG. 6, the positive electrode terminal 12 and the negative electrode terminal 13 are provided so as to protrude from the case 11. The positive terminal 12 and the negative terminal 13 are attached to the case 11 by a nut 22 via a resin collar 21 and a gasket 30 as shown in FIG. Thus, by attaching the positive electrode terminal 12 and the negative electrode terminal 13 to the case 11 via the resin collar 21 and the gasket 30, the electrical insulation between the positive electrode terminal 12 and the case 11 and the negative electrode terminal 13 and the case 11 are connected. It is designed to ensure electrical insulation and airtightness of the terminal mounting part.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-231192 (pages 2 and 3, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, the conventional terminal structure of the power storage element has a problem that an external short circuit may occur. For example, as shown in FIG. 8, when a water droplet 25 adheres to the positive electrode terminal 12 or the negative electrode terminal 13, the positive electrode terminal 12 and the case 11 or the negative electrode terminal 13 and the case 11 are electrically connected by the water droplet 25. Therefore, an external short circuit occurs. Here, even if the water droplet is smaller than the water droplet 25 shown in FIG. 8, the nut 22 and the case 11 are electrically connected to each other, so that an external short circuit occurs. If such a situation occurs in both the positive electrode terminal 12 and the negative electrode terminal 13, the entire power storage element is in an external short circuit state, and the function as the power storage element cannot be satisfied.
[0006]
As described above, the current planar gasket 30 cannot prevent the positive electrode terminal 12 and the case 11 or the negative electrode terminal 13 and the case 11 from being externally short-circuited. Even if the gasket 30 is made larger, water drops spread in the horizontal direction, so that it is not possible to prevent the occurrence of an external short circuit.
[0007]
Accordingly, the present invention has been made to solve the above-described problems, and even when water droplets or the like are attached, the terminal structure of the power storage element and the power storage in which the external terminal and the case are not externally short-circuited. It is an object to provide an element.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the terminal structure of the electricity storage device according to the present invention includes a conductive case for housing an electrode body, an external terminal for taking out power, and insulation between the external terminal and the case. In the terminal structure of the energy storage device comprising an insulating seal material for the purpose, a screw is formed on the external terminal, and a nut is screwed onto the screw and tightened via the insulating seal material, whereby the external terminal is The insulating sealing material is attached to a case, and has a wall portion formed higher than the nut so as to surround the nut along the axial direction of the external terminal .
[0009]
In this terminal structure of the electric storage element, the insulating sealing material for insulating between the external terminal and the case has a wall portion formed higher than the nut so as to surround the nut along the axial direction of the external terminal. Therefore, when water droplets or the like adhere to the external terminal, it is possible to prevent the external terminal and the case from being electrically connected by the adhering matter. That is, because the wall is formed higher than the nut so as to surround the nut along the axial direction of the external terminal, the adhering matter such as water droplets is divided and adheres to the insulating sealing material and the case, respectively. is there. Thus, since the external terminal and the case are not electrically connected, the entire power storage element does not enter an external short circuit state.
[0010]
A power storage device according to the present invention made to solve the above problems has the terminal structure described above.
[0011]
Since this power storage element uses the terminal structure described above, the external terminal and the case are not electrically connected, so that the entire power storage element does not enter an external short circuit state. Therefore, the function as a power storage element can be sufficiently exhibited without being influenced by the external environment.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a most preferred embodiment in which the terminal structure of a power storage element and the power storage element of the present invention are embodied will be described in detail based on the drawings. In the present embodiment, the present invention is applied to a battery that is used with an external terminal attached to the upper surface of a battery case and the external terminal facing upward.
[0013]
First, a schematic configuration of the battery according to the present embodiment is shown in FIG. FIG. 1 is a perspective view showing a schematic configuration of a battery. As shown in FIG. 1, the battery 10 according to the present embodiment has a square shape, and a positive electrode terminal 12 and a negative electrode terminal 13 are provided on the upper surface of the battery case 11.
[0014]
The battery case 11 includes a rectangular parallelepiped battery can 11a whose upper surface is opened and a lid plate 11b fitted into the opening. Since the battery can 11a and the cover plate 11b are not affected by the electrolytic solution and require mechanical strength that does not easily deform, aluminum, aluminum alloy, stainless steel, or the like is used. The battery case 11a is configured by joining the battery can 11a and the cover plate 11b by welding or the like.
[0015]
Here, an electrode body (not shown) inserted together with the electrolytic solution in the battery case 11 is formed by forming a layer of an active material that is an element of an electromotive reaction or a storage reaction on the surface of the current collector foil, A negative electrode is laminated via a separator. As a method for laminating the electrodes, several to several tens of both positive and negative electrodes may be used, and the positive and negative electrodes may be stacked alternately one by one (stacked type), The negative electrode may be used one by one, and the positive electrode and the negative electrode may be laminated so as to be wound in a roll shape or a flat roll shape (winding type).
[0016]
Two through holes are formed in the lid plate 11b, and the positive terminal 12 and the negative terminal 13 protrude and are fixed from these through holes. The positive terminal 12 and the negative terminal 13 are connected to an electrode body. Since the positive electrode terminal 12 and the negative electrode terminal 13 are electrically conductive and need not be eluted into the electrolytic solution by an electrochemical reaction, nickel, aluminum, or the like is used. A resin gasket 20 is attached to each attachment portion of the positive electrode terminal 12 and the negative electrode terminal 13 in order to ensure electrical insulation and airtightness with the battery case 11.
[0017]
Next, a terminal mounting structure, which is a characteristic part of the present invention, will be described with reference to FIGS. 2 and 3. FIG. 2 is a cross-sectional view showing the mounting structure of the positive terminal 12 of the battery 10. FIG. 3 is an exploded perspective view showing the attachment structure of the positive electrode terminal 12. The terminal mounting structure is the same for both the positive electrode and the negative electrode, and therefore the positive electrode terminal 12 will be described here. As shown in FIGS. 2 and 3, the attachment portion of the positive electrode terminal 12 includes the positive electrode terminal 12, a gasket 20, a collar 21, and a nut 22. The positive terminal 12 is inserted into the through hole of the cover plate 11b from the back side through the collar 21. In this state, the positive electrode terminal 12 protrudes from the lid plate 11b. A gasket 20 is inserted from above into the protruding positive terminal 12. That is, the cover plate 11 b is sandwiched between the gasket 20 and the collar 21. Then, by tightening the nut 22 from above the positive terminal 12, the positive terminal 12 is attached to the lid plate 11b. Here, since the gasket 20 and the collar 21 are resin members, they ensure electrical insulation between the positive electrode terminal 12 and the battery case 11 and airtightness of the mounting portion of the positive electrode terminal 12. Thereby, the battery 10 becomes a sealed structure.
[0018]
Here, a case where water droplets adhere to the vicinity of the terminal will be described with reference to FIG. FIG. 4 is a cross-sectional view of a portion of the positive electrode terminal 12 showing a state where the water droplet 25 is attached. As shown in FIG. 4, when the water droplet 25 adheres to the positive electrode terminal 12, it remains in the gasket 20 while the water droplet 25 is small. For this reason, the positive electrode terminal 12 and the cover plate 11b are not electrically connected by water droplets.
[0019]
Thereafter, when the adhesion amount of the water droplet 25 increases and the water droplet becomes larger, the water droplet 25 protrudes from the gasket 20. At this time, since the wall portion 20a is formed on the gasket 20, the enlarged water droplet 25 is divided into one that stays in the gasket 20 and one that falls on the cover plate 11b, as shown in FIG. The For this reason, the positive electrode terminal 12 and the cover plate 11b are not electrically connected by the water droplet 25.
[0020]
Moreover, since the terminal structure of the negative electrode terminal 13 is the same, the same phenomenon occurs. That is, even when the water droplet 25 adheres to the negative electrode terminal 13, the negative electrode terminal 12 and the lid plate 11 b are not electrically connected by the water droplet 25.
[0021]
Therefore, even if the water droplets 25 adhere to both the positive electrode terminal 12 and the negative electrode terminal 13, the positive electrode terminal 12 and the negative electrode terminal 13 are not electrically connected to the lid plate 11b, so that no external short circuit occurs. Thus, it is possible to prevent an external short circuit from occurring with a very simple configuration.
[0022]
As described above, in the battery 10 according to the present embodiment as described in detail, in order to ensure electrical insulation between the conductive battery case 11 that houses the electrode body and the positive electrode terminal 12 and the negative electrode terminal 13 for extracting power. Since the gasket 20 has a wall portion 20a formed along the axial direction of the positive electrode terminal 12 and the negative electrode terminal 13, when the water droplet 25 adheres to the positive electrode terminal 12 and the negative electrode terminal 13, the water droplet 25 becomes large. When it comes, it is divided and adheres to the inside of the gasket 20 and the lid plate 11b. Therefore, the positive electrode terminal 12 or the negative electrode terminal 13 and the battery case 11 are not electrically connected by the water droplet 25. Thereby, since an external short circuit does not occur, the battery 10 as a whole will not be in an external short circuit state. Therefore, the battery 10 can sufficiently exhibit its function without being influenced by the external environment.
[0023]
It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the gasket 20 having a shape different from that of the gasket used conventionally is used. However, as shown in FIG. A cylindrical wall member 40 may be fitted along the. In this case, the fit between the gasket 30 and the wall member 40 may be designed so that an interference fit can be achieved. However, when safety is taken into consideration, it is preferable to tighten the ring 41 or the like (preferably made of metal) from the outside of the wall member 40. In the above embodiment, the battery 10 has been described, but the present invention can be applied to a capacitor as well.
[0024]
Further, in the above-described embodiment, a battery of a type provided with a positive electrode terminal and a negative electrode terminal on the upper surface of the case has been described. For example, a type in which a positive electrode terminal and a negative electrode terminal are provided on opposite sides of both ends of a cylindrical case. The present invention can also be applied to these batteries. In this case, the terminal provided at the end of the case facing upward in the usage form of the battery may be the terminal structure according to the present invention.
[0025]
【The invention's effect】
As described above, the terminal structure of the power storage device according to the present invention includes a conductive case that houses an electrode body, an external terminal that extracts power, and an insulating seal material that insulates between the external terminal and the case. In the terminal structure of the energy storage device, the insulating sealing material has a wall portion formed along the axial direction of the external terminal, so when water droplets or the like adhere to the external terminal, It is possible to prevent the external terminal and the case from being electrically connected.
[0026]
In addition, since the power storage element according to the present invention has the above-described terminal structure, the external terminal and the case are not electrically connected, so that the entire power storage element is not short-circuited externally. Therefore, the function as a power storage element can be sufficiently exhibited without being influenced by the external environment.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a battery according to an embodiment.
FIG. 2 is a cross-sectional view showing a structure of a terminal mounting portion.
FIG. 3 is an exploded perspective view showing a terminal mounting portion.
FIG. 4 is a cross-sectional view showing a state when a water droplet adheres to a terminal.
FIG. 5 is a cross-sectional view showing a modification of the terminal attachment portion.
FIG. 6 is a perspective view showing a terminal structure of a conventional power storage element.
FIG. 7 is a cross-sectional view showing the structure of a conventional terminal mounting portion.
FIG. 8 is a cross-sectional view showing a state when water droplets adhere to a conventional terminal mounting portion.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Battery 11 Battery case 11a Battery can 11b Cover plate 12 Positive electrode terminal 13 Negative electrode terminal 20 Gasket 20a Wall part

Claims (2)

In a terminal structure of an electricity storage device comprising a conductive case that houses an electrode body, an external terminal for taking out power, and an insulating seal material for insulating between the external terminal and the case,
A screw is formed on the external terminal, and the external terminal is attached to the case by screwing a nut onto the screw and tightening it through the insulating sealing material,
The insulating seal material has a wall structure formed higher than the nut so as to surround the nut along the axial direction of the external terminal.   A power storage element having the terminal structure according to claim 1.

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