JP2003051315A - Thermal battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal battery having a stable and rapid voltage rise characteristic even in a low-temperature environment. SOLUTION: This thermal battery is provided with: a layered product comprising cells 12, exothermic agents 13 and an ignition plate 14, a fire guide hole 15a penetrating the layered product, and a fuse band disposed around the layered product. In the thermal battery, the ignition plate 14 comprises an ignition agent 15 and electric conduction parts 16 and carries current in the stacking direction by the electric conduction parts, and the ignition agent 15 is exposed to the fire guiding hole 15a at its center part and comes into contact with the fuse band at a circumferential end part. The diameter of the hole constituting the fire guide hole of the ignition agent is smaller than that of a hole constituting a fire guide hole of the electric conduction parts, the cells and the exothermic agents.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal battery, and more particularly to a high voltage, high output laminated thermal battery.

[0002]

2. Description of the Related Art In recent years, thermal batteries having high voltage, high output, and excellent high-speed startability have been developed. In order to increase the voltage of the thermal battery, there is a method of increasing the number of laminated unit cells and heat generating agents in the laminated thermal battery.

However, as the unit cells and the heat generating agent are stacked in multiple layers, the burning distance of the firing zone for igniting the stacked heat generating agents becomes longer, so that the voltage rise time of the thermal battery is delayed. Therefore, as a method for solving such a technical problem, a thermal battery having a configuration as disclosed in Japanese Patent Laid-Open No. 5-135781 has been proposed.

The structure of a conventional laminated thermal battery will be described with reference to FIG. The battery container 8 is composed of a battery case 9 and a battery lid 10, both of which are joined at a welded portion 11 to form a closed container. The battery container 8 accommodates a power generation section whose side surface is covered with the squib 3 and a heat insulating material 7 which surrounds the power generation section.

The battery lid 10 has a pair of output terminals 5a and 5a.
b and a pair of starting terminals 6a and 6b are installed.
The pair of output terminals 5a and 5b are connected to the inner lead plates 4a and 4b.
Are electrically connected to the lower part and the upper part of the squib 3. The starting terminals 6a and 6b are electrically connected to the igniter 1 by a pair of igniter lead wires.

An igniter 1 is provided in the upper portion of the power generation section whose side surface is covered with a squib 3, and a fire guide hole 2 penetrating the power generation section is formed inside. The power generation unit, as shown in FIG.
It is composed of a laminated body in which a unit cell 12, a heat generating agent 13, and an ignition plate 14 are laminated. As shown in FIG. 7, the ignition plate 14 includes a belt-shaped ignition agent 20, semi-circular metal pieces 17 arranged on both sides of the ignition agent 20, and two metal plates 16 sandwiching the ignition agent 20 and the metal piece 17. Become. The igniting agent 20 and the metal plate 16 have holes 20a and 16a having the same diameter for forming the ignition hole 2 penetrating through their centers. Therefore, the igniting agent 20 is exposed to the firing hole 2 at the central hole 20a and contacts the firing zone 3 at the outer peripheral end.

As shown in FIG. 8, the above-mentioned laminated body has a structure in which an ignition plate 14 is installed between a plurality of laminated body blocks 18 in which unit cells 12 and heat generating agents 13 are alternately deposited. The ignition plate 14 is also installed at the uppermost end and the lowermost end of the laminated body. Since the electrically conductive portion composed of the metal plate 16 and the metal piece 17 constituting the ignition plate 14 brings the electrically connected state between the laminated body blocks 18, all the laminated unit cells 12 are connected in series.

Next, with respect to the start-up of the conventional thermal battery, FIG.
This will be described with reference to FIG. The power generation section shown in FIG. 8 is composed of four laminated body blocks 18, and an ignition plate 14 is installed between them. Combustion propagates in the direction of the arrow shown in FIG.

First, the starting terminals 6a and 6b are energized from an external power source. As a result, a combustion flame is emitted from the igniter 1 toward the ignition hole 2, and the ignition agent 20 in the ignition plate 14 of each layer is generated.
Ignite The combustion of the ignition agent 20 diffuses in the outer peripheral direction, and when the combustion of the ignition agent 20 reaches the outer peripheral end, the ignition zone 3 is ignited. Then, the combustion of the squib 3 ignites the exothermic agent 13 in the laminate block 18. Further, the unit cell 12 is heated by the combustion of the exothermic agent 13. Then, when all of the stacked unit cells 12 are heated, a voltage is generated.

In this case, the distance between the ignition plates is the burning distance of the squib. Therefore, if the ignition plates are installed between the laminate blocks so that the firing distance of this ignition zone is uniform, the combustion is propagated along the route as shown in FIG. Is obtained. Further, since the ignition plate is installed between the laminated body blocks, the burning distance of the squib can be made constant regardless of the number of laminated unit cells and heat generating agents.

[0011]

High-power thermal batteries have been required to be used in a wider temperature environment. However, in a low temperature environment, the thermal battery having the above-described conventional structure has the same size of the holes forming the firing holes of the laminated body constituting member, and the portion where the ignition agent is exposed to the firing holes is extremely small. Since it is small and the temperature of the ignition agent itself is lowered, it becomes difficult to reach the ignition temperature for the ignition agent to reach combustion. Therefore, the combustion flame of the igniter does not surely propagate to the ignition agent in the ignition plate, and the combustion cannot propagate along the designed route. Therefore, there is a problem that the rise time of the voltage is delayed in a low temperature environment.

In order to solve the above problems, it is an object of the present invention to provide a thermal battery having stable and rapid voltage rising characteristics even in a low temperature environment.

[0013]

A thermal battery according to the present invention is provided with a laminated body composed of a unit cell, a heating agent and an ignition plate, a fire hole penetrating the laminated body, and an outer periphery of the laminated body. And a firing zone, the ignition plate is composed of an igniting agent and an electrical conducting portion, is conducted in the stacking direction by the electrical conducting portion, the igniting agent is exposed to the firing hole at the central portion, and at the end of the outer periphery. In a thermal battery in contact with a squib, the diameter of the hole forming the ignition hole of the igniting agent is smaller than the diameter of the hole forming the ignition hole of the electrical conducting portion, the unit cell and the heat generating agent. Is characterized by.

The ignition plate is composed of an ignition agent, two metal plates sandwiching the ignition agent, and a plurality of metal pieces interposed between the two metal plates and electrically connecting the two. Is preferred. Further, the ignition plate, a metal plate having a groove,
It is preferably composed of an igniting agent mounted in the groove of the metal plate and a metal plate sealing the groove of the metal plate. further,
It is preferable that the ignition plate is installed between a plurality of laminate blocks in which unit cells and heat generating agents are alternately stacked in multiple stages.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a laminate using the ignition plate of the present invention. FIG. 1 is a cross-sectional view showing the vicinity of an ignition plate of the laminate of the present invention. As shown in FIG. 1, the holes 15 a forming the ignition holes 2 of the igniting agent 15 are the components of the laminated body other than the igniting agent 15, the unit cell 12, the heat generating agent 13, and the ignition of the metal plate 16 forming the igniting plate 14. The structure is smaller than the hole forming the guide hole 2.

By thus increasing the exposed portion of the ignition agent to the firing hole, the degree of heating of the ignition agent by the combustion flame of the igniter is improved, and the ignition agent is reliably burned even in a low temperature environment. Can be propagated.

As a method for ensuring the combustion of the igniting agent in a low temperature environment, it is possible to use an igniter with a large combustion flame in addition to the above method. However, since it is required to be used in a wide temperature environment, when a battery is used in a high temperature environment, if the combustion flame of the igniter is large, excessive heating will damage the power generation section near the ignition hole. Danger occurs. Therefore, when a thermal battery is used in a wide temperature environment, the use of an igniter with a large combustion flame is not effective as a method for ensuring the combustion of the ignition agent.

FIG. 2 shows an embodiment of the ignition plate according to the present invention.
Shown in. In the ignition plate of FIG. 2, after welding two semicircular metal pieces 17 on the metal plate 16, the ignition agent 15 is inserted into the groove formed between the semicircular metal pieces 17, This is a structure in which a metal plate 16 is laminated on top.

Further, the embodiment of the ignition plate may have a configuration as shown in FIGS. 3 and 4 in addition to that shown in FIG. The ignition plate of FIG. 3 includes a plurality of circular metal pieces 17 and the metal pieces 17
A disc-shaped igniting agent 15 having a plurality of holes penetrating therethrough is sandwiched between two metal plates 16. In the ignition plate of FIG. 4, a groove portion 19 is formed in a thick metal plate 16 ′ by machining or chemical etching, and the ignition agent 1 is formed in the groove portion 19.
5 is mounted and the metal plate 16 is laminated on it.

According to the present invention, since the hole forming the ignition hole of the ignition agent is smaller than the hole forming the ignition hole of the laminated body constituent member other than the ignition agent, any one of FIGS. Also in the ignition plate having the structure, the diameter of the hole 15a forming the ignition hole of the ignition agent in the ignition plate is smaller than the diameter of the hole 16a forming the ignition hole of the metal plate. Further, the ignition plate is shown in FIGS.
Other than the above structure, any structure may be used as long as it is in an electrically conductive state in the stacking direction due to the electrically conductive portion, the igniting agent is exposed in the firing hole on the center side, and contacts the firing zone on the outer peripheral end side. Absent.

[0021]

EXAMPLES Examples of the present invention will be described below. <Example> A thermal battery of the present invention was manufactured by the following method. 130 unit cells were divided into four groups, and the unit cells and the heat generating agent were alternately deposited to form four laminated body blocks. The number of stacked unit cells and exothermic agents constituting each stack block is 33, 33, 32 for the unit cells in order from the igniter side.
The number of sheets was 32, and the number of exothermic agents was 34, 34, 33, 33. Then, an ignition plate having the structure shown in FIG. 2 was installed between each laminated body block. In addition, ignition plates were also arranged at the uppermost end and the lowermost end where the four laminated body blocks were laminated.

The diameter of the hole forming the ignition hole of the ignition agent was set to 4.5 mm. In addition, the diameter of the hole forming the ignition hole of the unit cell which is a laminated body constituent member other than the ignition agent, the heat generating agent and the metal plate forming the ignition plate was set to 5 mm. The outer diameter of the laminate composed of the four laminate blocks and the ignition plate arranged between them was 50 mm, and the height was 180 mm. As the ignition agent, zirconium and barium chromate in a weight ratio of 28:
The mixture was mixed at a ratio of 72, and the mixed powder to which glass fiber was added was used. In addition, the flame arresting zone provided on the outer periphery of the laminate had the same composition.

As the exothermic agent, a mixed molding of iron powder as a reducing agent and potassium perchlorate powder as an oxidizing agent was used. The unit cell was configured using a positive electrode containing iron disulfide as a main component, a negative electrode made of lithium or a lithium alloy, and an electrolyte in which a molten salt was adsorbed on magnesium oxide.

Five thermal batteries equipped with the above-described power generation section were prepared and the rise time of voltage was measured. -33 ° C so that the temperature inside the battery is uniform at -33 ° C.
The battery was left for 4 hours or more under the environment. Then, after standing, the battery was activated in an environment of −33 ° C., and the rise time of voltage was measured. The rise time of the voltage was the time from when the power was supplied to the igniter terminal and the igniter generated combustion flame until the battery voltage rose to the specified voltage of 230V.

<< Comparative Example >> The diameter of the hole forming the ignition hole of the ignition agent and the other laminate structure were the same as those of the examples except that the diameter of the hole forming the ignition hole of the ignition agent was 5 mm. Five thermal batteries having the same unit cell as the member, the heat generating agent, and the diameter of the hole forming the ignition hole of the metal plate forming the ignition plate were prepared, and the voltage rising time was increased in the same manner as in the example. Was measured. Table 1 shows the results of measuring the rise time of voltage using the thermal batteries of Examples and Comparative Examples.

[0026]

[Table 1]

In the thermal battery of the comparative example, in a low temperature environment of -33 ° C., the combustion flame emitted from the igniter to the ignition hole cannot be reliably propagated to the igniter, and the route is as designed. The combustion is not spread. For this reason, as shown in Table 1, the rise time of the voltage varied widely, and some of the five batteries did not satisfy the required value of 0.5 s.

On the other hand, in the thermal battery of the example of the present invention, as shown in FIG. 1, the exposure of the ignition agent to the ignition hole is larger than that of the thermal battery of the comparative example. Therefore, even in a low temperature environment of −33 ° C., the combustion flame emitted from the igniter to the ignition hole can reliably heat the igniting agent to the ignition temperature, and the combustion diffuses along the designed route. . Therefore, as shown in Table 1, variations in the rise time of the voltage were small, and all the batteries had the required value of 0.5 s or less.

As described above, it was found that the thermal battery of the example has a more stable and faster rise in voltage in the low temperature environment than the thermal battery of the comparative example.

[0030]

As described above, according to the present invention, it is possible to provide a thermal battery having stable and rapid voltage rising characteristics in a low temperature environment.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view near an ignition plate in a laminated body of a laminated thermal battery according to an example of the present invention.

FIG. 2 is an exploded perspective view of an ignition plate of the battery.

FIG. 3 is an exploded perspective view of an ignition plate according to another embodiment of the present invention.

FIG. 4 is an exploded perspective view of an ignition plate according to still another embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view of a laminated thermal battery.

FIG. 6 is a schematic cross-sectional view in the vicinity of an ignition plate in a laminated body of a conventional laminated thermal battery.

FIG. 7 is an exploded perspective view of a conventional ignition plate.

FIG. 8 is a schematic cross-sectional view of a laminated body of a conventional laminated thermal battery.

[Explanation of symbols]

1 igniter 2 Fire hole 3 fire zones 4a, 4b internal lead plate 5a, 5b output terminals 6a, 6b Starting terminal 7 insulation 8 battery container 9 battery case 10 Battery lid 11 welds 12 cells 13 Fever 14 Ignition board 15, 20 Ignition agent 15a, 20a Holes constituting ignition holes for ignition agent 16, 16 'metal plate 16a Holes that form fire holes in metal plate 17 metal pieces 18 laminated blocks 19 groove

Continued front page    (72) Inventor Kazuhiro Kimura             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Mitsuhiro Nakanishi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Keizo Oda             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 5H025 AA20 CC03 CC05 CC17 CC21                       CC25 CC34 CC39 KK02 KK07                       KK10

Claims (4)

[Claims] 1. A laminate comprising a unit cell, a heating agent, and an ignition plate, a fire hole penetrating the laminate, and a squib arranged on the outer periphery of the laminate, the ignition plate comprising: A thermal battery comprising an igniting agent and an electrically conducting portion, which is electrically conducted in the stacking direction by the electrically conducting portion, wherein the igniting agent is exposed in the firing hole at the central portion and contacts the igniting zone at the outer peripheral end, The thermal battery is characterized in that a diameter of a hole forming a firing hole of the ignition agent is smaller than a diameter of a hole forming a firing hole of the electric conduction portion, the unit cell and the heat generating agent. 2. The ignition plate comprises an ignition agent, two metal plates sandwiching the ignition agent, and a plurality of metal pieces interposed between the two metal plates and electrically connecting the two. The thermal battery according to claim 1, wherein 3. The ignition plate, a metal plate having a groove,
The thermal battery according to claim 1, comprising an igniting agent mounted in the groove of the metal plate and a metal plate sealing the groove of the metal plate. 4. The thermal battery according to claim 1, wherein an ignition plate is installed between a plurality of laminated body blocks in which unit cells and heat generating agents are alternately stacked in multiple stages.