JPH05174843A - Laminated thermal cell and its manufacture - Google Patents

Abstract

PURPOSE:To provide a thermal cell of rapid electromotive, high output and high capacity as a cell generating a high voltage, by pinching a multiple- laminated stack with a specified pressure and inserting it in a cell case. CONSTITUTION:A cell stack consisting of elemental cells 1, in which fused salt is used, and exothermic agent 2 mounted alternately on each other is pinched with a jig or a tool as an unit, and inserted in a cell case 26. The lower portion of the jig or the tool is detached from an aperture on a case closing plate 22 on the bottom of the cell case 26, and the upper portion of the jig or the tool is welded to a cell cover 17 to pressurize downward, and the aperture of the case closing plate 22 is sealed tightly with an aperture sealing plate 23.

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 laminated thermal battery that outputs a high voltage and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, electronic devices used mainly in personal devices and also in special devices have been rapidly reduced in size, high in output, and maintenance-free. In particular, there is a strong demand for improvement and development of a thermal battery as a driving power source, which has high voltage, large output, and high-speed startability. Therefore, as a power source for driving the electric servomotor, there are great expectations for development of a lithium thermal battery in that it can realize the above-mentioned various characteristics. And when developing a high-voltage type thermal battery, a temporary battery performance can be obtained by increasing the number of layers of the unit cell and the heat generating agent by the conventional technique based on a known layered battery.
As the number of stacked layers increases, the number of unit cells and the number of heat generating agents increase, the contact resistance between the stacked layers increases, and the output decreases more. Also, the heat of combustion of the heat generating agent is less likely to propagate to the unit cell, and the starting time of the battery (in the present specification, after the starting time is input to the thermal battery, the voltage is 70% of the maximum voltage of the thermal battery). The time to reach it will be referred to as the startup time hereinafter) is delayed.

On the other hand, also in the battery structure, since the laminated body formed by depositing the unit cell and the heat generating agent (hereinafter, this laminated body is referred to as a stack) has an elongated cylindrical shape, the unit cell and the heat generating agent are laminated. If the unit cells and the heat generating agent are tilted because the pressure balance is broken even a little when the stack is constructed, the manufacturing of the elongated cylinder becomes difficult because the tilt becomes large as a whole. In addition, when loading this stack into the battery case, there is a method of taping with heat resistant tape to prevent loosening the pressing force above and below the stack, or fixing with a metal holding jig and then removing it from the jig and inserting it. Since it is used, an extra item such as a heat-resistant tape remains in the battery, or the pressure for forming the stack is loosened by removing the pressing jig from the stack, and the battery characteristics are deteriorated. Then, an example of a battery case into which a conventional thermal battery stack is inserted will be described with reference to the drawings.

FIG. 7 shows the first conventional example, in which the battery case 91 has substantially the same thickness at the side portion and the bottom portion. Since the battery case 91 has a bottom portion manufactured by drawing or cutting, it has an advantage of being inexpensive, but since the stack tightening pressure can be loosened when the cell stack is loaded, the final assembly pressure cannot be grasped,
Therefore, there is a drawback that the quality is not stable. There is also a problem that the bottom of the case expands when the internal pressure of the battery rises. Next, the battery case 101 of Conventional Example 2 shown in FIG. 8 has a case lower plate 103 which is thicker than the side wall 102.
The case lower plate 103 is fitted to the case 02 and then externally welded 104. Also in this example, since the structure is similar to that shown in FIG. 7, the pressure applied to the stack is loosened. Therefore, each of the battery cases of the conventional structure shown in FIGS. 7 and 8 undergoes a step of assembling the stack, then once removing it from the pressure-fastening jig or tool, assembling it with the battery lid, and inserting it into the battery case. There was a need. As a result, the stack dimensions become unstable and the output characteristics, internal resistance,
It appeared as many characteristic issues such as discharge capacity, starting characteristics, and environmental performance.

[0005]

As described above, the conventional problem to be solved by the present invention is that, when the multi-layer stack is inserted into the battery case, the vertical pressing force is loosened and the internal resistance is increased, resulting in various battery problems. The point was that the performance was degraded.

The present invention solves the problems of the conventional thermal battery as described above, and realizes high-speed stacked type thermal battery in spite of being a high-output laminated thermal battery, has a small internal resistance of the battery, output characteristics, discharge capacity, etc. The first is to provide excellent battery performance
The second object is to provide a manufacturing method capable of easily manufacturing the above-mentioned laminated thermal battery.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a case closing plate for closing the bottom of a battery case containing a multi-stacked stack mainly composed of unit cells and a heating agent, A battery lid that seals the opening of the battery case facing the case closing plate, wherein the case closing plate is provided with an opening through which a clamping force is applied to the battery lid side by a jig outside the battery case. A laminated thermal battery having a sealing plate for sealing the opening is provided in the opening. Also, a stacking step with a jig for pressing the stack through the opening of the case closing plate between the battery lid side, and a step of inserting the stack into the battery case during the stacking step,
Laminated heat that has a process of welding one or both of a battery lid and a sealing plate that seals the opening of the case closing plate to the battery case while the stack is being pressed, and a process of removing the jig and tool. A method of manufacturing a battery is provided.

[0008]

According to the structure of the present invention, the tightening pressure during assembly of the stack does not change until the battery is completed in which the stack is inserted into the battery case and the battery lid is welded. There is no irregularity in the contact state of each laminated block. And the stack dimensions do not become unstable, the output characteristics deteriorate due to partial electrode reaction, the output voltage decreases due to an increase in internal resistance, the startup time is delayed due to the deterioration of heat transfer efficiency, and the vibration and shock due to the decrease in structural strength. Has little effect on sex. Further, in the manufacturing process, the stack is attached to the battery completion process by the jig and tool through the opening of the case closing plate, which is advantageous in that the manufacturing is easy. Furthermore, when the stack is formed by using the through firing holes, the igniter can be attached in the final step, so that the safety of the operator due to accidental ignition can be improved.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 1, reference numeral 1 is a unit cell composed of a negative electrode 10 made of lithium or a lithium alloy, an electrolyte 11 obtained by impregnating a ceramic with a molten salt, and a positive electrode 12 containing iron disulfide as a main component. .. Reference numeral 2 is an exothermic agent, which is a mixed molding of iron powder as a reducing agent and potassium perchlorate powder as an oxidizing agent. 3 is an ignition plate, 4 is a unit cell, a heating agent, a firing hole penetrating the ignition plate, 5 is an electric igniter, and 6 is an ignition zone provided on the outer peripheral side surface of the stack. Reference numeral 7 is a disc called an ignition pad that ignites the squib from both ends of the stack. Reference numerals 8 and 8a denote internal lead plates, and a pair of output terminals 9 and 9a, and 13 and 13a.
Are electrically connected to a pair of igniter lead wires at a pair of starting terminals. Reference numeral 14 is a side heat insulating material arranged on the side surface of the stack, 15 is a lid heat insulating material, 15a is a lid center heat insulating material, 16 is a bottom heat insulating material, and 16a is a bottom center heat insulating material. The battery upper lid is composed of a battery lid 17 having a pair of output terminals and an igniter lid 18 having a pair of starting terminals, and is fitted into a battery case, and then has a hermetically sealed structure with lid welding portions 19 and 19a. Reference numeral 21 is a stack lower plate, 22 is a case closing plate, and 23 is a case closing plate 2.
A sealing plate for sealing the two through holes, 26 is a battery case, 27 is internal welding, and 28 is external welding.

In the laminated thermal battery of Example 1, since the lower case closing plate 22 has an opening, the negative electrode 10 and the electrolytic solution 1
1. A stack including the unit cell 1 composed of the positive electrode 12, the heat generating agent 2, the ignition plate 3 and the like as constituent elements is used by using jigs up and down using the battery lid 17 and the opening of the case closing plate 22. The battery lid 17 is welded to the opening of the battery case 26 by the lid welding portion 19 with the tightening pressure applied, and then the jig for receiving the lower portion of the battery is removed, and the opening of the case closing plate 22 is closed with the sealing plate 23. The inner welding 27 is made by sealing. Therefore, since the stack completes the battery with the pressure applied from above and below, the internal layers are in good contact with each other, and the internal resistance is low, which reduces battery capacity and delays the startup time. is there.

(Embodiment 2) FIG. 2 shows a cross section of only the lower main part of the laminated thermal battery. The central through hole of the thick case closing plate 22 below the lower stack plate 21 is shown in FIG. There is a sealing plate 23 that closes this. The central cylindrical portion of the stack lower plate 21 forming the through hole 24a is the case closing plate 22.
It is fitted in the opening 25 of the. The sealing plate 23 is internally welded 27 to the peripheral edge of the central through hole of the case closing plate 22 fitted to the battery case 26, and the outer peripheral edge portion of the case closing plate 22 is externally welded 28 to the battery case 26 so that the lower end of the battery case 26 is closed. Is blocked. At the center of the case closing plate 22, there is a protruding portion 30 having a screw 29 engraved on the outer circumference. The screw 29 of the protruding portion 30 corresponds to the laminated thermal battery of the second embodiment,
It is attached by screwing it into the screws of the equipment used. In the second embodiment, the through hole 2 is formed in the center as described above.
Although the stack inserted into the battery case 26 due to the presence of 4a is not shown, it is possible to insert a depressing tool into the battery lid and the through hole 24a to apply depressing force from above and below. Then, the stack is inserted into the battery case in a pressed state, the battery lid is welded to the upper part of the battery case, the lower part of the pressing tool is removed from the through hole 24a, and the sealing plate 23 is internally welded 27 to close the through hole 24a. Can be done. Therefore, the stack loaded in the battery case is pressed from above and below by the pressing tool, and the contact between the stack layers is good.
It provides low internal resistance, quick start-up time, and high battery capacity.

(Embodiment 3) FIG. 3 shows only the main part of the lower end portion of the laminated thermal battery case, but in Embodiment 3 the battery lower lid 2 is used.
The stack lower plate 21 constituting the
1a is provided. Further, a step portion 22a for accommodating the stack lower plate 21 is provided on the outer periphery of the case closing plate 22.
The above-mentioned stack lower plate protrusion 21a of the stack lower plate 21 is fitted into the opening 25 at the center of the case closing plate 22, and the inner welding 2
The stepped portion 22a of the case closing plate 22 is externally welded 28 to the lower end of the battery case 26.
Of course, in the third embodiment also, since the stack lower plate protrusion 21a is provided, the jig supporting the lower end of the stack lower plate protrusion 21a is projected into the battery case through the opening 25 of the case closing plate 22 and is not shown. The stack is pressed between the battery cover and the upper battery lid, and the stack is inserted into the battery case 26 in the pressed state, and the jig is lowered to move the stack lower plate protrusion 21a to the case closing plate 22. Of the opening 25 by fitting it into the opening 25 of the
Is to be occluded. Therefore, the components of the stack can be packaged in the battery case while being pressed, the contact between the layers of the stack is good, and the internal resistance is low.

(Embodiment 4) FIG. 4 shows only the main part of the lower end of the laminated thermal battery case, but the difference from Embodiment 3 is as follows.
Instead of the case closing plate, there is a case bottom 26a formed integrally with the battery case 26 by drawing, and the opening 25 at the center thereof projects downward. Therefore, the battery lower lid 20 is composed of the stack lower plate 21 having the stack lower plate protrusion 21a and the case bottom portion 26a. The stack in the battery case 26 is inserted while being pressed, and a thermal battery having excellent battery characteristics can be provided as in the case of the third embodiment.

(Embodiment 5) FIG. 5 is a longitudinal sectional view of a laminated thermal battery in a manufacturing process in Embodiment 5 of the present invention to show a manufacturing method. In FIG. 5, reference numeral 40 denotes a jig, which is composed of a stack rod 41, a pressing plate 42, and a fixing screw 43. The stack components are stacked, sandwiched between the stack lower plate 21 and the battery lid 17, and tightened to a predetermined pressure. In this state, the battery case 26 and the case lower plate 22 are preliminarily loaded into the case integrated by the outer welding 28, and the stack rod receiving portion 41a is opened.
5, the battery lid 17 and the battery case 26 are fitted and fixed by welding at the lid welding portion 19. After that, remove the jig 40,
As shown in FIG. 5B, the sealing plate 23 is fitted into the opening 25 and inner welding 27 is performed. Only the main part of the lower end of the thermal battery in Example 5 is shown in FIG. 5B as a sectional view.
Others are the same as the first embodiment shown in FIG. As described above, in the fifth embodiment, the stack components are loaded in the battery case 26 in a state of being clamped to the predetermined pressure in the vertical direction, and the battery lid 17 and the sealing plate 23 are welded to the battery case, respectively. .. Therefore, good contact can be maintained between the layers forming the stack.

(Embodiment 6) FIG. 6 is a sectional view of a laminated thermal battery in a manufacturing process in Embodiment 6 of the present invention to show a manufacturing method. Then, the lower end portion of the thermal battery is changed from the state shown in FIG. 6A to the state shown in FIG.

In FIG. 6, a stack component having no firing hole is sandwiched between the stack lower plate 21 and the battery lid 17, and clamped from above and below to a set pressure by a tool 44 using a hydraulic cylinder or the like. The battery case 26 is inserted into the stack, welded and fixed as in the fifth embodiment, and then the tool 44 is removed.

Also in the sixth embodiment, since the stack component is loaded in the battery case while being fastened with the tool 44 and the battery lid 17 and the stack lower plate protrusion 21a are welded, the stack component is placed between the layers. The contact pressure can maintain a strong state, and therefore there is no defect such as high internal pressure of the battery.

Although the first to sixth embodiments have been described with reference to the drawings, the starting method for the first embodiment will be described.

When a pulse current is supplied from the external power source to the starting terminals 13 and 13a, the igniter 5 fires toward the ignition hole 4 and ignites the ignition plate 3 of each layer. The ignition plate burns and diffuses in the outer peripheral direction to ignite the squib 6 and sequentially ignite the heat generating agent 2. The exothermic agent 2 burns to heat the unit cell 1 to about 550 ° C. to generate power, and the entire stack becomes in an active state. The output terminal generates a maximum voltage of 275 V when, for example, 120 unit cell stacks are configured in series, drives an external load such as an electric servomotor, and outputs an average operating voltage of 220 V. The stack is kept warm by an insulating material and can be supplied with power for a specified time. Since the battery is a completely sealed type, it has no influence on the peripheral electronic devices.

Next, a prototype of a high-voltage type thermal battery using the battery case shown in FIGS. 7 and 8 of the conventional example and ones according to Examples 1 to 6 were prepared for each starting time, internal resistance and discharge. The results of capacity comparison are shown in (Table 1).

[0022]

[Table 1]

It can be seen from Table 1 that the examples of the present invention are superior to the conventional examples in all of the starting time, internal resistance and discharge capacity.

[0024]

As is apparent from the above description, according to the present invention, the stack is assembled in a state in which the stack is fixedly clamped, and the battery lower lid is composed of the stack lower plate and the case closing plate having the opening or the case bottom. The laminated thermal battery has the advantages that the startup time is short, the internal resistance is small, the discharge capacity is large, and a stable discharge voltage can be exhibited.

Moreover, the manufacturing method thereof is simple and the conventional problems can be easily solved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a laminated thermal battery according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a lower main part of a laminated thermal battery according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of a lower main part of a laminated thermal battery according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view of an essential part of a lower part of a laminated thermal battery according to a fourth embodiment of the present invention

FIG. 5 (A) is a vertical cross-sectional view of a laminated thermal battery in a manufacturing process according to a fifth embodiment of the present invention.

FIG. 6 (A) is a vertical cross-sectional view of a laminated thermal battery in a manufacturing process according to a sixth embodiment of the present invention.

FIG. 7 is a cross-sectional view of essential parts below a battery case in Conventional Example 1.

FIG. 8 is a cross-sectional view of essential parts below a battery case in Conventional Example 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 unit cell 2 exothermic agent 3 ignition plate 17 battery lid 19, 19a lid welding part 20 battery lower lid 21 stack lower plate 22 case closing plate 23 sealing plate 25 opening 26 battery case 27 inner welding 28 outer welding 40 jig 41 stack Rod 41a Stack rod holder 42 Push plate 43 Fixing screw

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Go Hatanaka 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (9)

[Claims] 1. A case closing plate that closes a bottom portion of a battery case that houses a unit cell and a multi-layered stack mainly composed of a heat generating agent, and a battery lid that closes an opening of the battery case facing the case closing plate. The case closing plate is provided with an opening through which a clamping force applied to the battery lid side by a jig outside the battery case is inserted, and the opening has a sealing plate for sealing the same. .. 2. The laminated thermal battery according to claim 1, wherein the case closing plate has its outer peripheral edge externally welded to the lower end of the battery case, and the opening thereof is internally welded to the sealing plate. 3. The laminated thermal battery according to claim 1, wherein the case closing plate has a protrusion provided with a screw for screwing into a device using the battery. 4. The laminated thermal battery according to claim 1, wherein the case closing plate has an opening into which a stack lower plate protrusion of the stack lower plate located above the case closing plate fits. 5. A laminated thermal battery in which a stepped portion for accommodating a stack lower plate is provided on the outer peripheral edge of the case closing plate in claim 4. 6. A case closing plate is integrally formed with a side wall of a battery case, and a stack lower plate protrusion of a stack lower plate on the case closing plate is fitted into an opening of the case closing plate to perform internal welding. The laminated thermal battery according to claim 1, 3, 4, or 5. 7. The laminated thermal battery according to claim 1, wherein the battery upper lid for sealing the upper opening of the battery case by welding has a battery lid and an igniter lid. 8. A depressurizing step using a jig for depressing a multi-layered stack mainly composed of a unit cell and a heat generating agent through an opening of a case closing plate between the cell lid side and a battery during the depressurizing step. A step of inserting the multi-layered stack in the case,
A step of welding either one or both of the battery lid and the sealing plate for sealing the opening of the case closing plate to the battery case while the multi-layered stack is being pressed, and a step of removing the jig and tool. A method of manufacturing a laminated thermal battery having the same. 9. A step of externally welding an outer peripheral edge of a case closing plate to a lower end of a side wall of a battery case, and a stack lower plate projecting portion of a stack lower plate which overlaps the case closing plate and supports a multi-layered stack. 9. The method for manufacturing a laminated thermal battery according to claim 8, further comprising the step of fitting into the opening of the closing plate and performing internal welding.