JP2003163036A - Battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery which makes temperature inside a battery container hard to rise. <P>SOLUTION: In the battery locating radiator components at a terminal part of an electrode terminal, the invention comprises that a radiator component 5 includes a first radiating part having a first proximal radiating part 51 which extends from the terminal parts 13, 23 and is located near the terminal parts 13, 23, and a first distal radiating part 52 which extends from the proximal radiating part, and a second radiating part having a second proximal radiating part 51 which extends from the terminal parts 13, 23 and is located on downstream side in predetermined direction of the first distal radiating part 52 and a second distal radiating part 52 which extends from the second proximal radiating part 51 and is located on the downstream side in the predetermined direction of the first proximal radiating part 51. In other words, variation of the cooling effect can be controlled as much as possible by taking notice that there are the proximal radiating part 51 which is higher in temperature and the distal radiating part 52 which is relatively low in temperature and can not seek cooling effect among the same radiator components and by alternately arranging the proximal radiating part 51 and the distal radiating part 52 against a flow of a cooling medium. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery, and more particularly to a battery in which a heat radiating member is fixedly arranged at a terminal portion.

[0002]

2. Description of the Related Art In recent years, electric vehicles such as electric vehicles and hybrid vehicles have been actively developed. As a power source for driving this electric vehicle, there is an increasing demand for a secondary battery having excellent performance, reliability, and safety.

In these electric vehicles, the driving power source is required to have high electromotive force and energy density. As this driving power source, a battery in which a large number of battery cells having a positive electrode and a negative electrode and causing an electrode reaction are connected in series or in parallel is used in order to obtain high electromotive force and energy amount. In this battery, a large number of battery cells are usually enclosed in an integrated container in an isolated state. A battery having such a structure is called a monoblock battery, and many proposals have been made.

When a large current is discharged, the battery cells generate heat due to the electrode reaction between the positive electrode and the negative electrode. Due to this heat generation, the battery cell is overheated, the positive electrode and / or the negative electrode is damaged by the heat, and the performance of the battery is deteriorated. For this reason, it has been necessary for the battery to take heat dissipation measures for the purpose of preventing the storage heat of the battery against the heat generated by a large current.

A battery provided with heat dissipation measures is disclosed, for example, in Japanese Utility Model Laid-Open No. 61-39860.

Japanese Utility Model Laid-Open No. 61-39860 discloses a battery having a through-hole through which air circulates in a partition wall partitioning a battery cell chamber of a battery container of a monoblock battery. In this battery, the partition wall portion is cooled by the air circulating through the through hole of the partition wall portion, and the electrode body housed in the battery cell chamber partitioned by the partition wall portion can be cooled in a wide area.

However, since the space of the through hole and the partition wall need a thickness of two layers to separate the through hole, a large space for the partition wall is required, resulting in poor battery mounting efficiency. There was a drawback.

Further, Japanese Unexamined Patent Publication No. 10-144266 discloses a battery container for a monoblock type battery, which comprises a battery container having an outer wall and an inner wall in which metal parts are coated with a resin.

Although the battery container can efficiently transfer heat to the surroundings by the portion made of metal parts, heat conduction from the electrode body to the metal parts and from the outer wall of the container to the outside are possible. Since heat conduction is performed through the resin portion, it is necessary to form the resin portion extremely thin in order to obtain sufficient heat dissipation, and there is a problem that there is a difficulty in forming the container.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a battery that is excellent in mountability and productivity and that the temperature inside the battery container does not easily rise. .

[0011]

In order to solve the above problems, the inventors of the present invention have made extensive studies on batteries capable of radiating internal heat, and as a result, have arranged a heat radiating member at the terminal portion of the electrode terminal. It was found that the above problems can be solved by.

That is, a battery container containing an electrode element having at least a positive electrode and a negative electrode therein, a terminal portion electrically connected to each of the positive electrode and the negative electrode and protruding from the battery container, and fixed to the terminal portion. A battery having a heat radiating member for radiating the heat of the battery container transmitted to the terminal portion.

It was found that the cooling efficiency of the heat dissipating member of this battery varies depending on the place where it is disposed. That is,
This is because the heat dissipation member that first contacts the cooling medium that cools the heat dissipation member is cooled well, but the cooling efficiency of the heat dissipation member that subsequently contacts the cooling medium gradually decreases.

In the battery of the present invention for solving this problem, the heat dissipation member extends from the terminal portion and is located near the terminal portion.
A first heat radiation portion having a near heat radiation portion and a first far heat radiation portion extending from the first near heat radiation portion, and a second heat radiation portion extending from the terminal portion and located downstream of the first far heat radiation portion in the predetermined direction. A second heat radiation part having a near heat radiation part and a second far heat radiation part extending from the second near heat radiation part and located downstream of the first near heat radiation part in the predetermined direction.

That is, among the same heat radiating members, paying attention to the fact that there are a near heat radiating part having a higher temperature and a far heat radiating part having a relatively low temperature and not requiring a high cooling efficiency, a plurality of heat radiating members are provided. By classifying into the first heat radiating portion and the second heat radiating portion, and disposing the near heat radiating portion and the far heat radiating portion alternately with respect to the flow of the cooling medium, it is possible to suppress variations in cooling efficiency as much as possible. is there.

Further, in the battery of the present invention for solving the above-mentioned problems, the heat dissipation member has a heat dissipation member base portion, and a cross-sectional area of the heat dissipation member base portion in a direction perpendicular to the predetermined direction becomes narrower toward the downstream in the predetermined direction. It is characterized by having a radiation fin portion forming a path.

That is, as the cooling medium flows downstream, the flow velocity of the cooling medium can be increased by narrowing the cross-sectional area of the flow path of the cooling medium through which the cooling medium flows. As a result, the cooling medium flows from the cooling member to the cooling medium. Since the heat flow (that is, the cooling efficiency) improves as it goes downstream, it is possible to suppress the decrease in the cooling efficiency on the downstream side to a minimum.

In the battery of the present invention, the internal heat of the battery has little variation and can be dissipated from the heat dissipating member, so that deterioration of the battery performance due to overheating can be suppressed. As a result, the battery of the present invention can have long life and high performance.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION A battery according to the present invention comprises a battery container having therein an electrode element having at least a positive electrode and a negative electrode.
A battery having a terminal portion that is electrically connected to each of the positive electrode and the negative electrode and protrudes from the battery container, and a heat radiation member that is fixed to the terminal portion and radiates heat of the battery container that is transmitted to the terminal portion. .

As the battery of the present invention, any battery may be used as long as it has the above structure. That is, it may be a primary battery or a secondary battery, and may be any type of battery such as a lead storage battery, a Ni-Cd battery, a Ni-MH battery, or a lithium battery. Further, the shape of the battery is not particularly limited, and may be a cylindrical battery or a prismatic battery.

The battery may have a plurality of electrode elements. In that case, it may be an assembled battery in which a plurality of batteries are stacked, or a monoblock type battery in which a battery container is divided into a plurality of cell chambers accommodating a plurality of electrode elements.

The number of terminals is not limited to two, positive and negative.
You may have more than one. For example, in a battery having a plurality of electrode elements, each electrode element can have a terminal portion.

The battery of the present invention has a heat radiating member fixedly arranged at the terminal portion. That is, the heat generated from the positive electrode and the negative electrode inside the battery is transferred to the heat radiating member via the terminal portion of the joined electrode terminal, and this heat is radiated from the heat radiating member to the outside air or the like. Therefore, in the battery of the present invention, the heat generated from the positive electrode and the negative electrode inside the battery does not stay inside the battery container, and the positive electrode and the negative electrode are prevented from being damaged by the heat. This heat dissipation member may be electrically connected to the terminal portion or may be insulated. When the heat dissipation member is electrically connected to the terminal portion, be careful of short-circuiting due to contact between the heat dissipation members.

As a first form, the heat dissipation member includes a first heat dissipation part having a first near heat dissipation part extending from the terminal part and near the terminal part and a first far heat dissipation part extending from the first near heat dissipation part, and the terminal. A second near heat radiating portion extending from the first portion and located downstream of the first far heat radiating portion in the predetermined direction, and a second far heat radiating portion extending from the second near heat radiating portion and located downstream of the first near heat radiating portion in the predetermined direction. And a second heat dissipating part having. The predetermined direction is a direction in which a cooling medium such as air flows to the heat dissipation member when the present battery is used. This flow may be generated by a mechanical device such as a fan, or may be left to a natural flow.

It is preferable that the first heat radiation portion and the second heat radiation portion are separate members. For example, the heat radiating members extending from the positive and negative electrodes can be classified into a first heat radiating portion and a second heat radiating portion, respectively, and in the case of a battery having two or more electrode elements, the first heat radiating portion and the second heat radiating portion. A plurality of combinations can be provided.

When there are a plurality of terminal portions, the terminal portions are spaced apart in the predetermined direction, the first heat radiating portion is fixed to the terminal portion located upstream in the predetermined direction, and the second
The heat dissipation part can be fixed to the terminal part located on the downstream side in the predetermined direction.

Further, it is preferable that the heat radiating member comprises a heat radiating member base and a heat radiating fin portion for increasing the surface area of the heat radiating member from the viewpoint of improving cooling efficiency.

Further, the heat dissipating member has a second form.
The heat dissipating member base portion and the heat dissipating fin portion form a heat dissipating fin portion that forms a flow path with which the cross-sectional area in the direction perpendicular to the predetermined direction becomes narrower toward the downstream side in the predetermined direction. By gradually narrowing the cross-sectional area of this flow path, the flow speed of the cooling medium flowing through the flow path is increased.

Further, it is preferable that the heat radiation member has a surface area increasing toward the downstream side in the predetermined direction. The cooling efficiency increases as the surface area increases toward the downstream side, and thus the cooling efficiency imbalance is improved.

When there are a plurality of sets of terminals,
Not limited to the first form and the second form, it is preferable that this heat dissipation member has a metal portion on at least a part of the heat dissipation member in order to connect a plurality of electrode elements in series or in parallel. By electrically connecting the metal portions between the terminal portions, the heat radiating member and the wiring member for passing current can be made common, and the number of parts can be reduced.

[0031]

(Example 1) (Structure) As shown in FIG. 1, a battery according to this example has a strip-shaped positive electrode 41 and a negative electrode 42 and a separator 43 interposed between both electrodes.
An electrode body 4 as an electrode element in which and are flatly wound,
Positive electrode terminal 1 and negative electrode 4 connected to the positive electrode 41 of the electrode body 4.
2 and the negative electrode terminal 2 connected to 2. The positive electrode 41 and the negative electrode 42 are edge portions which are not coated with the electrode active material and which protrude from the separator in opposite directions along the winding axis length direction, and are connected to the positive electrode terminal 1 and the negative electrode terminal 2, respectively. It has protruding end portions 411 and 421.

Both the positive electrode terminal 1 and the negative electrode terminal 2 are made of a metal conductor, and the protruding end portions 411, 42 of the electrode body 4 are formed.
Shaft parts 11 and 21 and flange parts 12 and 22 joined to 1
And terminal portions 13 and 23 used for electrical connection with the outside. The terminal portions 13 and 23 are composed of screw portions 131 and 231, and nut portions 132 and 232, respectively.
The negative electrode terminal 2 has a gasket 6 made of an insulator that hermetically seals the inside of the battery between the flange portions 12 and 22 and the case 3 and insulates the positive electrode terminal 1 and the negative electrode terminal 2 from the case 3, and the terminal portion 13, Screw parts 131 and 231 forming 23
It is fixed to the container 3 by fastening the nut portions 132 and 232.

The present battery has 6 electrodes each having an electrode element.
It is an assembled battery in which two batteries are stacked.

The heat dissipating member 5 has a comb-teeth cross-sectional shape, and has a base 51 as a heat dissipating member base (and a near heat dissipating part) and a plurality of heat dissipating fin parts (and far heat dissipating parts) extending to one side of the base 51 surface. And the fin portion 52 as
Further, one end of the base portion 51 has one end portion of the electrode terminals 1 and 2.
It is fixed by abutting on 3, 23. The heat dissipating member 51 is arranged in a total of 6 in a state of contacting the terminal portions 13 and 23 at a total of 12 places of the assembled battery at two places respectively, and is connected to the terminal portions 13 and 23 by the nut 7. The cooling medium flows in the direction of the drawing in the space formed by the heat dissipation member 5 and the battery case 3. With respect to the illustrated flow direction, each of the two heat radiating members 5 arranged on the inlet side and the outlet side of the cooling medium, a total of four heat radiating members 5 are arranged so that the fin portion 52 extends downward with the base portion 51 as an upper surface. On the other hand, each of the two heat radiation members 5 arranged in the middle is arranged such that the base portion 51 is the lower surface and the fin portion 52 extends upward. That is, of the three heat dissipation members 5 arranged in the predetermined direction, the first corresponds to the first heat dissipation part and the second corresponds to the second heat dissipation part. Further, if the second one corresponds to the first heat radiating portion, the third one can correspond to the second heat radiating portion.

FIG. 2 shows a sectional structure of a portion including the positive electrode terminal 1, the negative electrode terminal 2 and the electrode body 4 shown in FIG. Electrode body 4
Is a sheet-shaped positive electrode 41 in which a positive electrode active material layer 412 is formed on both surfaces of a conductive sheet 413 made of aluminum.
A sheet-shaped negative electrode 42 in which a negative electrode active material layer 422 is formed on both surfaces of a conductive sheet 423 made of copper;
1 and the negative electrode 42, and two sheet-shaped separators 43 interposed respectively. The separator 43 is a polyethylene or polypropylene sheet that is formed wider than the regions in which the electrode active materials 412 and 422 are applied to both electrodes 41 and 42. The shaft portion 11 of the positive electrode terminal 1 and the shaft portion 21 of the negative electrode terminal 2 have protruding end portions 411 and 42, respectively.
Connected to 1.

(Operation) The battery of this embodiment has the following operations and effects due to the above-mentioned structure.

The heat generated in the electrode body 4 due to the charging / discharging reaction of the battery is conducted by the conductive sheets 413, 42 constituting the electrode body 4.
An electrode terminal 1 composed of a good thermal conductor connected to 3.
The heat is quickly transferred to the outside of the battery case 3 via the heat transfer member 2, and is further transferred to the heat dissipation member 5 fixed to the terminal portions 13 and 23 of the electrode terminals 1 and 2. Therefore, the heat generated in the electrode body 4 can be efficiently removed by cooling the heat dissipation member 5. Cooling of the heat dissipation member 5 is performed by flowing air as a cooling medium in a predetermined direction.

Here, the heat generated in the electrode body 4 is applied to the terminal portion 1.
Since the heat-dissipating member 5 moves to the respective parts of the heat-dissipating member 5, the base 51 of the heat-dissipating member 5 has a relatively higher temperature than the fin part 52. Therefore, the cooling medium passing near the base portion 51 is likely to receive heat and its temperature further rises, so that the cooling ability after that is large. In the battery of this embodiment, 3 in the predetermined direction.
Since the positions of the base portion 51 and the fin portion 52 are alternately arranged in the vertical direction in one heat radiation member, the cooling medium alternately passes through the base portion 51 and the fin portion 52, which have a high temperature. Although the cooling capacity of the cooling medium that has passed through the base portion 51 first decreases, the cooling capacity of the cooling medium is sufficient because it passes through the fin portion 52 that does not require so much heat radiation. On the contrary, the temperature of the cooling medium which has passed through the fin portion 52 having a relatively low temperature first does not rise so much and the cooling capacity does not decrease, so that the base portion 51 which requires large heat radiation thereafter can be sufficiently cooled. This relationship is the first set (1st and 2nd) in a given direction
And common to all the second set (2nd and 3rd) heat dissipation member. Therefore, the heat can be efficiently dissipated regardless of the position of the heat dissipating member, so that the entire battery can be efficiently cooled.

(Modification of Embodiment 1) FIG. 3 shows a modification of the heat dissipating member 5 in the battery of Embodiment 1, in which the heat dissipating member 5'has a shape folded back in a triple cross section in a direction perpendicular to the predetermined direction. Hold. The heat dissipation member 5'has a high temperature on the side of the end portion 53 contacting the terminal portions 13 and 23 (near heat dissipation portion), and the end portion 5 on the opposite side.
The temperature is low on the 4th side (far heat dissipation part). The heat dissipating member 5'is the end 5
3 and the end portion 54 are alternately arranged in the vertical direction (specifically, at both ends in the predetermined direction, the end portion 53 is lower and the end portion 54 is upper, and in the center, the end portion 53 is upper and the end portion 54 is lower). did.

Therefore, the air, which is the cooling medium, alternately flows through the end portion 53 requiring large heat dissipation and the end portion 54 requiring relatively small heat dissipation, so that the battery can be efficiently cooled.

Example 2 (Structure) The battery of Example 2 is obtained by changing the heat dissipation member 5 of the battery of Example 1 as shown in FIG. That is,
The heat dissipating member 5 "includes three types of members 51 ', 52', 53 '.
Composed of. Three types of members 51 ', 52', 53 '
Has a corrugated cross section in the direction perpendicular to the predetermined direction, and the interval between the corrugations becomes narrower toward the downstream side in the predetermined direction.

The members 51 ′, 52 ′ and 53 ′ are fixed in contact with the terminal portions 13 and 23 at a total of 12 locations of the assembled battery at four locations, respectively.
It is concluded in 3. The cooling medium flows in the direction of the arrow (predetermined direction) in the figure, and the cross-sectional area perpendicular to the predetermined direction of the flow passage becomes narrower as it advances to the members 51 ', 52', 53 '.

(Function) The electrode body 4 is charged by the charge / discharge reaction of the battery.
The heat generated in the conductive sheet 41 that constitutes the electrode body 4 is generated.
Heat dissipation that is quickly transmitted to the outside of the battery case 3 via the electrode elements 1 and 2 made of a good thermal conductor connected to the electrodes 3 and 423, and further directly contacts the terminal portions 13 and 23 of the electrode terminals 1 and 2. Heat is transferred to the member. Therefore, the heat of the electrode body 4 can be efficiently removed by cooling the heat dissipation member 5 with the cooling medium.

At this time, the cooling medium has a large amount of heat exchange possible on the upstream side, but has a small amount of heat exchange on the downstream side due to the temperature rise of the fluid itself. Therefore, by narrowing the flow path of the cooling medium in the heat dissipation member on the downstream side, the flow velocity on the downstream side can be increased and the heat exchange capacity can be secured.

Further, in this embodiment, the heat dissipation member has a cross-sectional shape such as a corrugated fin, so that the fin interval can be narrowed on the downstream side and the number of fins can be increased to easily narrow the flow path. Since the heat dissipation area of the heat dissipation member can be increased, it is possible to more effectively suppress the temperature rise of the downstream battery and uniformly cool the entire assembled battery.

(Modification of Embodiment 2) FIG. 5 shows a modification of the heat dissipation member according to the present invention.
Has a plurality of protruding fin portions 54 '
Similar to the previous embodiment, the space between the fin portions 54 'is wide on the upstream side of the cooling medium, and the space between the fin portions 54' is narrow on the downstream side. That is, the flow path of the cooling medium is narrowed and the heat radiation area of the heat radiation member is increased toward the downstream side. As can be seen from this example, the present invention can be configured using very simple parts.

(Other Modifications) In the battery of Example 1, six batteries were stacked to form one battery, but the battery container was a complete monoblock type battery container having six cell chambers. It can also be a structure (Fig. 6).

Furthermore, since the cooling efficiency of the heat radiating member is high, it is possible to use a resin agent having low thermal conductivity for the battery container.

If the heat dissipation member 5 is made of a good electrical conductor such as metal, it can be used as a wiring member for connecting the terminals 13 and 23.

In Example 1, the positive electrode 41, the negative electrode 42, and the separator 43 were wound as the structure of the electrode body 4, but the positive electrode, the negative electrode, and the separator were stacked in layers. A laminated electrode body can also be used.

Further, in the embodiment of the present invention, an example of the heat dissipating member which is in contact with both the terminal portion of the positive electrode terminal and the terminal portion of the negative electrode terminal is shown. However, in the case of contacting only one of the terminal portions. However, the same effect is exhibited. Further, although the example has been described with the example of the battery container having a rectangular shape, the same effect can be exhibited also in the cylindrical battery by similarly arranging the heat dissipation member in contact with the terminal portion. In addition, although the example of the lithium battery has been described in the present example, other typical batteries such as a lead storage battery, a Ni-Cd battery, and a Ni battery are used.
In the -MH battery, the structure of the electrode body and the structure of the electrode terminal are generally the same, so that the present invention exerts a sufficient effect.

[0052]

As described above, the battery of the present invention is
By fixing the heat dissipation member to the terminal part of the electrode terminal, the heat inside the battery is transferred from the terminal part of the electrode terminal to the heat dissipation member.
The heat dissipation member radiates heat to the outside. At this time, by making the shape of the heat dissipation member appropriate, it is possible to reduce unevenness of the heat dissipation ability depending on the location of the heat dissipation member. Therefore, overheating inside the battery is suppressed, and deterioration of battery performance due to overheating is suppressed. Therefore, the battery of the present invention exhibits the effect of having high performance and long life.

[Brief description of drawings]

FIG. 1 is a cross-sectional perspective view of a battery of Example 1.

FIG. 2 is a diagram showing a configuration of an electrode body and an electrode terminal of the battery of Example 1.

FIG. 3 is a perspective view of a battery of a modified example of the first embodiment.

FIG. 4 is a cross-sectional perspective view of a battery of Example 2.

FIG. 5 is a perspective view of a battery of a modified example of the second embodiment.

FIG. 6 is a sectional view of a battery of another modification.

[Explanation of reference numerals] 1 ... Positive electrode terminal 2 ... Negative electrode terminal 3 ... Battery container 4 ... Electrode body 5 ... Heat sink 6 ... Gasket 7 ... Nut

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuhiro Oga             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO F term (reference) 5H028 BB05 CC01 CC05                 5H031 KK01 KK06 KK08

Claims (7)

[Claims] 1. A battery container having therein an electrode element having at least a positive electrode and a negative electrode, and terminal portions which are electrically connected to the positive electrode and the negative electrode and project from the battery container.
A heat dissipating member that dissipates heat of the battery container fixed to the terminal portion and transferred to the terminal portion, wherein the heat dissipating member extends from the terminal portion and is close to the first portion. A first heat radiation portion having a heat radiation portion and a first far heat radiation portion extending from the first near heat radiation portion, and a second near portion extending from the terminal portion and located downstream of the first far heat radiation portion in the predetermined direction. A second heat radiation portion having a heat radiation portion and a second far heat radiation portion extending from the second near heat radiation portion and located downstream of the first near heat radiation portion in the predetermined direction;
A battery having: 2. A plurality of the terminal portions are arranged at intervals in the predetermined direction, and the first heat radiating portion is fixed to the terminal portion located upstream of the predetermined direction, The battery according to claim 1, wherein the heat dissipation portion is fixed to the terminal portion located on the downstream side in the predetermined direction. 3. The battery according to claim 1, wherein the heat dissipation member includes a heat dissipation member base portion and a heat dissipation fin portion that increases a surface area of the heat dissipation member. 4. A battery container having therein an electrode element having at least a positive electrode and a negative electrode, and a terminal portion electrically connected to each of the positive electrode and the negative electrode and protruding from the battery container.
A battery having a heat dissipation member for radiating heat of the battery container fixed to the terminal part and transmitted to the terminal part, wherein the heat dissipation member is perpendicular to a predetermined direction together with the heat dissipation member base part. A heat dissipating fin portion forming a flow passage whose cross-sectional area in the direction becomes narrower toward the downstream side in the predetermined direction. 5. The battery according to claim 1, wherein the heat dissipation member has a surface area that increases toward the downstream side in the predetermined direction. 6. The battery according to claim 1, wherein the battery container is partitioned into a plurality of cell chambers accommodating a plurality of the electrode elements. 7. A battery in which a plurality of the electrode elements are connected in series or in parallel, wherein the heat dissipation member has a metal portion at least in part, and the metal portion electrically connects between the terminal portions. The battery according to claim 1.