JP2015162294A - electrochemical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrochemical device which is high in heat dissipation property.SOLUTION: An electrochemical device according to an embodiment of the present invention comprises: a case; a power storage device; a first terminal; a second terminal; and a heat dissipation part. The case has a case main body and a metal lid. The case main body includes: a bottom face; a circumferential face formed to connect to the bottom face; and a first inner face. The lid is joined with the case main body and includes a second inner face opposed to the first inner face; a liquid room is formed between the case main body and the lid. The power storage device has an electrolytic solution, a first electrode part disposed on the first inner face, and a second electrode part connected to the second inner face, and it is housed in the liquid room. The first terminal is formed on the bottom face, and connected with the first electrode part. The heat dissipation part has: a first metal line formed inside the case main body to extend from the lid toward the bottom face; and an exposed part connected to the first metal line and the second terminal and formed in the circumferential face.

Description

  The present invention relates to an electrochemical device including a chargeable / dischargeable power storage element.

  Electrochemical devices including a chargeable / dischargeable power storage element are widely used for backup power supplies and the like. One such electrochemical device has a structure in which an insulating case and a metal lid constitute a liquid chamber, and a storage element containing an electrolytic solution is enclosed in the liquid chamber. The positive electrode of the electricity storage element is connected to the positive electrode terminal formed on the bottom surface via the wiring, and the negative electrode is connected to the negative electrode terminal formed on the bottom surface via the metal lid and the wiring (see Patent Document 1). .

JP 2013-232569 A

  By the way, the electricity storage element generates heat during charging and discharging. At this time, the negative electrode side connected to the metal lid was relatively easy to radiate heat, but the positive electrode side was hardly radiated, and exhaust heat as a whole electrochemical device was not sufficiently achieved. In particular, when charging / discharging at a relatively high voltage, the electrolytic solution may become high temperature and deteriorate, which may shorten the product life. In addition, the liquid chamber has a high pressure, and the joint between the lid and the case and the case body may be damaged, leading to problems such as liquid leakage.

  In view of the circumstances as described above, an object of the present invention is to provide an electrochemical device with high heat dissipation.

In order to achieve the above object, an electrochemical device according to an embodiment of the present invention includes a case, a power storage element, a first terminal, a second terminal, and a heat dissipation portion.
The case has a case main body and a metal lid. The case body includes a bottom surface, a peripheral surface formed to be connected to the bottom surface, and a first inner surface. The lid includes a second inner surface that is joined to the case body and faces the first inner surface, and forms a liquid chamber between the case body and the lid.
The power storage element includes an electrolytic solution, a first electrode portion disposed on the first inner surface, and a second electrode portion connected to the second inner surface, and is accommodated in the liquid chamber. The
The first terminal is formed on the bottom surface and connected to the first electrode portion.
The heat radiating portion extends from the lid toward the bottom surface and is connected to the first metal wire formed inside the case body, the first metal wire, and the second terminal, and is connected to the peripheral surface. And an exposed portion formed.

1 is a perspective view of an electrochemical device according to a first embodiment of the present invention. It is a longitudinal cross-sectional view of the said electrochemical device. It is a longitudinal cross-sectional view of the structure which removed the lid, the coupling ring, and the electrical storage element of the said electrochemical device. It is a top view of the said structure. It is a cross-sectional view which shows the structure of the connection part of the thermal radiation part of the said electrochemical device. It is a principal part longitudinal cross-sectional view explaining the effect of the said electrochemical device. It is a longitudinal cross-sectional view of the electrochemical device which concerns on the 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the structure which removed the lid, the coupling ring, and the electrical storage element of the said electrochemical device. It is a longitudinal cross-sectional view of the electrochemical device which concerns on the 3rd Embodiment of this invention.

An electrochemical device according to one embodiment of the present invention includes a case, a power storage element, a first terminal, a second terminal, and a heat dissipation portion.
The case has a case main body and a metal lid. The case body includes a bottom surface, a peripheral surface formed to be connected to the bottom surface, and a first inner surface. The lid includes a second inner surface that is joined to the case body and faces the first inner surface, and forms a liquid chamber between the case body and the lid.
The power storage element includes an electrolytic solution, a first electrode portion disposed on the first inner surface, and a second electrode portion connected to the second inner surface, and is accommodated in the liquid chamber. The
The first terminal is formed on the bottom surface and connected to the first electrode portion.
The heat radiating portion extends from the lid toward the bottom surface and is connected to the first metal wire formed inside the case body, the first metal wire, and the second terminal, and is connected to the peripheral surface. And an exposed portion formed.

  According to the above configuration, the heat generated by the first and second electrode portions of the energy storage device with charge / discharge is transmitted to the metal lid and the exposed portion via the first metal wire of the heat dissipation portion. The heat is dissipated. Therefore, it is possible to provide an electrochemical device having a long life by suppressing deterioration of the electrolyte solution due to heat generation of the power storage element. In addition, problems such as electrolyte leakage can be prevented.

Further, the heat radiating portion has a plurality of first metal wires extending from the lid toward the bottom surface and formed respectively inside the case body,
The exposed portion may be connected to each of the plurality of first metal wires.

  According to the above configuration, the heat dissipation efficiency can be increased by the plurality of first metal wires. Furthermore, the heat at the time of welding the lid and the case main body can be uniformly cooled. It is also possible to increase the strength of the case body.

Alternatively, the heat dissipation part is
A second metal wire connected to the lid, extending from the lid toward the bottom surface, and formed inside the case body;
The exposed portion may be configured not to be electrically connected to the second metal line.

  As a result, the second metal wire can transfer the heat generated by the power storage element to the lid and cool it.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Electrochemical devices]
FIG. 1 is a perspective view of an electrochemical device 10 according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the electrochemical device 10. As shown in these drawings, the electrochemical device 1 includes a case 10, a power storage element 13, a positive electrode terminal (first terminal) 14, a positive electrode wiring 15, a negative electrode terminal (second terminal) 16, and a heat dissipation portion 17. .

  As shown in FIG. 2, the electrochemical device 1 is configured by enclosing a storage element 13 and an electrolytic solution L in a liquid chamber 11 a formed inside the case 10. As will be described in detail later, the positive electrode of the electricity storage element 13 is electrically connected to the positive electrode terminal 14 via the positive electrode wiring 15 formed inside the case body 11, and the negative electrode of the electricity storage element 13 is connected to the lid 12 and the heat radiating portion 17. Is electrically connected to the negative electrode terminal 16 via.

  The case 10 includes a case main body 11, a lid 12, and a coupling ring 18. The case 10 has a configuration in which a case main body 11 and a lid 12 are joined via a coupling ring 18, and a liquid chamber 11 a is formed therein.

  The case body 11 is insulative and is made of an insulating material such as ceramics. The case body 11 includes a bottom surface 111, a peripheral surface 112 formed so as to be connected to the bottom surface 111, and a first inner surface 113. For example, a rectangular parallelepiped shape as shown in FIG. It can be formed into a shape. The case body 11 may be formed with a recess that constitutes the liquid chamber 11 a, and the bottom surface of the recess may be configured as the first inner surface 113.

  The case body 11 is manufactured by, for example, an HTCC process or an LTCC process. That is, the case main body 11 mixes a ceramic material, and molds a plurality of ceramic sheets using a mold or the like. These ceramic sheets can be laminated and fired at a predetermined temperature.

  The lid 12 is made of metal and forms a liquid chamber 11 a between the case body 11 and the lid 12. The lid 12 includes a second inner surface 121 that is joined to the case main body 11 and faces the first inner surface 113. The coupling ring 18 is joined to the second inner surface 121, and the second inner surface 121 can be joined to the case body 11 via the coupling ring 18. The lid 12 is formed of a metal material such as Kovar (iron-nickel-cobalt alloy), for example. Alternatively, the lid 12 may be a clad material in which a base material such as Kovar is coated with a coating made of a highly corrosion-resistant metal such as nickel, platinum, silver, gold, or palladium in order to prevent electrolytic corrosion. It is.

  The coupling ring 18 is configured as an annular seal member, and is formed of a metal material such as Kovar. For joining the coupling ring 18 and the second inner surface 121 of the lid 12, for example, a direct joining method such as seam welding or laser welding can be used, or an indirect joining method with a conductive joining material can be applied. Further, the coupling ring 18 and the case body 11 may be joined by brazing.

  The electric storage element 13 is accommodated in the liquid chamber 11a, and accumulates (accumulates) electric charges or discharges (discharges) electric charges. As shown in FIG. 2, the electric storage element 13 includes an electrolytic solution L, a first electrode portion 131 disposed on the first inner surface 113, and a second electrode portion connected to the second inner surface 121 of the lid 12. 132 and a separate sheet 133. The power storage element 13 can have a configuration in which a separate sheet 133 is sandwiched between the first electrode portion 131 and the second electrode portion 132.

  Specifically, the first electrode portion 131 may include an electrode sheet and an adhesive layer that adheres to the first inner surface 113. Similarly, the second electrode portion 132 may include an electrode sheet and an adhesive layer that adheres the electrode sheet to the second inner surface 121 of the lid 12. The constituent material of each electrode sheet of the 1st electrode part 131 and the 2nd electrode part 132, and the separate sheet | seat 133 can be suitably selected according to a required characteristic. For example, each electrode sheet can be made of a material containing an active material, and the separate sheet 133 can be a porous sheet mainly made of glass fiber, cellulose fiber, plastic fiber or the like. The adhesive layer may include a conductive adhesive.

  The positive electrode terminal 14 is formed on the bottom surface 111 and connected to the first electrode portion 131, and functions as an external terminal used for connection to a mounting substrate or the like. Specifically, the positive electrode terminal 14 is connected to the positive electrode (first electrode portion 131) of the power storage element 13 by the positive electrode wiring 15.

  The positive electrode wiring 15 electrically connects the first electrode portion 131 of the power storage element 13 and the positive electrode terminal 14. The configuration of the positive electrode wiring 15 is not particularly limited. For example, as shown in FIG. 2, a via 151 extending from the positive electrode terminal 14 toward the bottom surface 111 and an internal wiring that runs in the case body 11 in a direction substantially parallel to the bottom surface 111. 152 and a terminal connection portion 153 formed on the peripheral surface 112 and connected to the positive electrode terminal 14 may be included.

  The negative electrode terminal 16 is formed on the bottom surface 111 and functions as an external terminal used for connection to a mounting substrate or the like. Specifically, the negative electrode terminal 16 is connected to the negative electrode (second electrode portion 132) of the electricity storage element 13 by the heat radiating portion 17, the lid 12, and the coupling ring 18.

  In the present embodiment, the heat dissipating part 17 electrically connects the lid 12 connected to the second electrode part 132 of the power storage element 13 and the negative electrode terminal 16. The heat radiating portion 17 includes a plurality of metal wires (first metal wires) 171, an exposed portion 173, and a connecting portion 174.

  FIG. 3 is a longitudinal sectional view of the configuration in which the lid 12, the coupling ring 18 and the storage element 13 are removed. As shown in FIGS. 2 and 3, each metal wire 171 extends from the lid 12 toward the bottom surface 111 and is formed inside the case body 11. Each metal wire 171 is connected to the coupling ring 18 of the lid 12 at the upper end, and is connected to the exposed portion 173 via the connection portion 174 at the lower end. Each metal wire 171 may travel linearly inside the case body 11, or may travel while meandering or bending. Each metal wire 171 may be arranged in parallel to each other.

  FIG. 4 is a plan view of the configuration in which the lid 12 and the storage element 13 are removed. Each metal wire 171 is formed in a cylindrical shape, for example, as shown in the figure, but may be formed in an elliptical column shape, a rounded column shape, or the like. The plurality of metal wires 171 are arranged so as to surround the liquid chamber 11a, and may be arranged equally spaced apart, for example. Further, for example, four metal wires 171 among the plurality of metal wires 171 may be arranged at corners of the case body 11. The number of the metal wires 171 is not particularly limited.

  The plurality of metal wires 171 can be manufactured simultaneously with the case body 11. That is, a hole is formed at a predetermined position of a ceramic sheet constituting a part of the case body 11, and a metal material is embedded therein. By laminating and firing such a plurality of ceramic sheets, a plurality of metal wires 171 are formed in the case body 11. The material of the plurality of metal wires 171 is not particularly limited, but tungsten can be used when the HTCC process is used, and silver can be used when the LTCC process is used.

  FIG. 5 is a cross-sectional view showing the shape of the connecting portion 174. The connection part 174 connects the plurality of metal wires 171 and the exposed part 173. Although the connection part 174 may be comprised cyclically | annularly as shown in the figure, it is not limited to this, Arbitrary shapes can be taken.

  The exposed portion 173 is formed on the peripheral surface 112 and is connected to the plurality of metal wires 171 (connecting portions 174) and the negative electrode terminal 16. For example, the exposed portion 173 is formed in a strip shape extending from the connecting portion 174 toward the bottom surface 111.

[About heat dissipation part]
FIG. 6 is a schematic cross-sectional view of the main part for explaining the operational effects of the heat radiating part 17. In addition, the arrow in the figure shows the heat transfer direction. The storage element 13 generates heat at the positive electrode (first electrode portion 131) and the negative electrode (second electrode portion 132) during charging and discharging. In particular, when charging / discharging is performed at a relatively high voltage, the electrolyte L has a high temperature, and deterioration is accelerated, which may shorten the product life. Moreover, the pressure in the liquid chamber 11a is increased by heating the electrolytic solution L, and there is a possibility that problems such as liquid leakage from the joint portion of the lid 12 and the coupling ring 18 and damage to the case body 11 may occur.

  Thus, according to the present embodiment, the heat radiating unit 17 can efficiently radiate the heat generated due to charging / discharging. Specifically, as shown in FIG. 6, the heat generated around the negative electrode is transferred from the metal wire 171 to the lid 12 through the coupling ring 18 and cooled by the metal lid 12. On the other hand, heat generated around the positive electrode is transmitted from the metal wire 171 to the exposed portion 173 via the connecting portion 174 and is cooled by the exposed portion 173. Thus, by having the exposed part 173, it becomes possible to efficiently dissipate not only the negative electrode but also the heat generated around the positive electrode. Therefore, deterioration of the electrolytic solution L can be suppressed, and the lifetime of the electrochemical device 1 can be increased, and problems such as liquid leakage can be suppressed.

  Furthermore, since the heat radiating part 17 has the exposed part 173, the metal wire 171 can be configured not to penetrate the case body 11. If the metal wire penetrates the inside of the case body 11, the metal wire may protrude from the bottom surface 111 due to thermal expansion during firing, and the positive electrode terminal 14 and the negative electrode terminal 16 are connected to an external mounting substrate or the like. It may become defective. Therefore, it becomes possible to perform the connection with the exterior satisfactorily by configuring the heat dissipating part 17 as described above.

  Furthermore, the heat radiating part 17 has a plurality of metal wires 171. Thereby, the heat generated in the positive electrode and the negative electrode can be efficiently transmitted to the lid 12 and the exposed portion 173, and the cooling efficiency can be improved.

  Further, by arranging the plurality of metal wires 171 evenly spaced apart, the generated heat can be efficiently and uniformly cooled even when the case body 11 (the coupling ring 18) and the lid 12 are welded. It becomes possible. Thereby, local distortion of the lid 12 due to non-uniform temperature distribution can be prevented.

  In addition, the strength of the case body 11 can be increased by having the plurality of metal wires 171 in the case body 11. Accordingly, it is possible to prevent the case body 11 from being distorted or damaged. Furthermore, even if one metal wire 171 breaks, the negative electrode of the electricity storage element 13 and the negative electrode terminal 16 can be electrically connected, and the possibility of connection failure can be reduced.

<Second Embodiment>
FIG. 7 is a cross-sectional view of the electrochemical device 2 according to the second embodiment of the present invention. As shown in the figure, the electrochemical device 2 includes a power storage element 13, a positive electrode terminal (first terminal) 14, a positive electrode wiring 15, and a negative electrode terminal (second terminal) 16 having the same configuration as the electrochemical device 1. In addition, a case 20 and a heat dissipation part 27 are provided. The case 20 includes a case main body 21, a lid 12, and a coupling ring 18. In the following description, the same reference numerals are used for the same configurations as those in the first embodiment, and the description thereof is omitted.

  FIG. 8 is a vertical cross-sectional view of a configuration in which the lid 12, the coupling ring 18, and the power storage element 13 are removed. The case body 21 has the same schematic configuration as the case body 11. That is, the case body 21 is insulative and has a bottom surface 211, a peripheral surface 212 formed to be connected to the bottom surface 211, and a first inner surface 213. The first inner surface 213 can be configured as a bottom surface of a recess that constitutes the liquid chamber 21a.

  The heat radiating portion 27 electrically connects the lid 12 connected to the second electrode portion 132 of the power storage element 13 and the negative electrode terminal 16. The heat radiating portion 27 includes a plurality of first metal wires 271, a plurality of second metal wires 272, an exposed portion 273, and a connecting portion 274.

  Each first metal wire 271 extends from the lid 12 toward the bottom surface 211 and is formed inside the case main body 21, similarly to the metal wire 171. Each first metal wire 271 is connected to the lid 12 via the coupling ring 18 at the upper end and is connected to the exposed portion 273 via the connection portion 274 at the lower end. The number of the first metal wires 271 is not particularly limited.

  Each second metal wire 272 is connected to the lid 12 via the coupling ring 18, extends from the lid 12 toward the bottom surface 211, and is formed inside the case body 21. As will be described later, second metal line 272 is non-conductive with exposed portion 273. The number of the second metal lines 272 is not particularly limited, and for example, a configuration having only one second metal line 272 may be used.

  The arrangement of the first metal line 271 and the second metal line 272 is not particularly limited. For example, it may be alternately arranged around the liquid chamber 21 a, or four first metal wires 271 are arranged at the corners of the case body 21, and 1 or between the adjacent first metal wires 271. A plurality of second metal wires 272 may be arranged.

  The connection part 274 connects the plurality of metal wires 271 and the exposed part 273. The exposed portion 273 is formed on the peripheral surface 212 in the same manner as the exposed portion 173, and is connected to each of the plurality of first metal wires 271 (connecting portions 274) and the negative electrode terminal 16. Further, the exposed portion 273 is configured to be non-conductive with the second metal wire 272.

  According to the present embodiment, the heat dissipating unit 27 includes a plurality of second metal wires 272 in addition to the plurality of first metal wires 271. Such a second metal wire 272 can also transfer heat to the lid 12. As described above, it is possible to efficiently cool the structure having the plurality of second metal wires 272 used only for heat transfer, not as wiring.

<Third Embodiment>
FIG. 9 is a cross-sectional view of the electrochemical device 3 according to the third embodiment of the present invention. As shown in the figure, the electrochemical device 3 includes a power storage element 13, a positive electrode terminal (first terminal) 14, a positive electrode wiring 15, and a negative electrode terminal (second terminal) 16 having the same configuration as the electrochemical device 1. In addition, a case 30 and a heat radiating part 37 are provided. The case 30 includes a case main body 31, a lid 12, and a coupling ring 18. In the following description, the same reference numerals are used for the same configurations as those in the first embodiment, and the description thereof is omitted.

  The case body 31 has the same schematic configuration as the case body 11. That is, the case main body 31 is insulative and has a bottom surface 311, a peripheral surface 312 that is connected to the bottom surface 311, and a first inner surface 313. The first inner surface 313 can be configured as a bottom surface of a recess that constitutes the liquid chamber 31a.

  The heat dissipating part 37 electrically connects the lid 12 connected to the second electrode part 132 of the power storage element 13 and the negative electrode terminal 16. The heat dissipation part 37 includes a metal wire 371, an exposed part 373, and a connection part 374.

  Similarly to the metal wire 171, the metal wire 371 extends from the lid 12 toward the bottom surface 311 and is formed inside the case body 31. In the present embodiment, the heat radiating portion 37 has one metal wire 371.

  The connection part 374 connects the metal wire 371 and the exposed part 373. The exposed portion 373 is formed on the peripheral surface 312, similarly to the exposed portion 173, and is connected to the metal wire 371 (connecting portion 374) and the negative electrode terminal 16.

  According to the present embodiment, the metal wire 371 is connected to the lid 12 and the exposed portion 373, and heat dissipation can be improved. Furthermore, the formation of the ceramic sheet at the time of manufacture can be facilitated.

The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

  The cross-sectional shape of the connecting portion is not particularly limited. Further, the shape of the exposed portion is not particularly limited, and may be configured to surround the peripheral surface.

  Although it has been described that the lid is joined to the case body via the coupling ring, the lid may be configured without the coupling ring. In this case, the 1st metal wire and 2nd metal wire of a thermal radiation part can be directly connected to a lid.

DESCRIPTION OF SYMBOLS 1, 2, 3 ... Electrochemical device 10, 20, 30 ... Case 11, 21, 31 ... Case main body 11a, 21a, 31a ... Liquid chamber 111, 211, 311 ... Bottom 112, 212, 312 ... Peripheral surface 113, 213 , 313 ... First inner surface 12 ... Lid 121 ... Second inner surface 13 ... Power storage element 131 ... First electrode portion 132 ... Second electrode portion 14 ... Positive electrode terminal (first terminal)
16: Negative terminal (second terminal)
17, 27, 37... Heat radiating portion 171, 271, 371... First metal wire 272.

Claims (3)

A case main body including a bottom surface, a peripheral surface connected to the bottom surface, and a first inner surface; and a second inner surface bonded to the case main body and facing the first inner surface. A case having a metal lid that forms a liquid chamber with
An electricity storage device having an electrolytic solution, a first electrode portion disposed on the first inner surface, and a second electrode portion connected to the second inner surface, and housed in the liquid chamber;
A first terminal formed on the bottom surface and connected to the first electrode portion;
A second terminal formed on the bottom surface;
An exposed portion formed on the peripheral surface that extends from the lid toward the bottom surface and is connected to the first metal wire formed inside the case body, the first metal wire, and the second terminal. An electrochemical device comprising: a heat dissipating part. The electrochemical device according to claim 1,
The heat dissipating part has a plurality of first metal wires extending from the lid toward the bottom surface and formed respectively inside the case body,
The exposed portion is an electrochemical device connected to each of the plurality of first metal wires. The electrochemical device according to claim 1 or 2,
The heat dissipation part is
A second metal wire connected to the lid, extending from the lid toward the bottom surface, and formed inside the case body;
The exposed portion is an electrochemical device configured to be non-conductive with the second metal wire.

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