JPS6121800Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a metal holding plate that holds a laminated group in which unit cells and heat generating agents are stacked alternately at both upper and lower ends of the metal holding plate. By providing an opening in the plate that is concentric with the conduit hole and having a larger diameter than the conduit hole, and arranging a heat-resistant insulating member with the same conduit hole diameter inside the opening, short circuits are prevented and the output characteristics are improved. The aim is to supply stable thermal batteries.

Thermal batteries use molten salt as the electrolyte, such as KCl-LiCl,
It is a type of high-temperature battery using KBr-LiBr, etc., and is used as an emergency power source because it has many characteristics such as excellent storage stability and the ability to extract a large amount of electric power. Many of these types of batteries contain a heat generating agent inside, and the heat generated by the heating agent melts molten salt, which is solid at room temperature and has no ion conductivity, and is activated as a battery.

A conventional stacked thermal battery has a configuration as shown in FIG. In the figure, 1 is a unit cell and 2 is a heat generating agent, which is made from a mixture of a reducing substance such as zirconium and an oxidizing substance such as barium chromate as shown in, for example, Japanese Utility Model Publication No. 53-26176. These are alternately laminated, and metal holding plates 3 are disposed at both upper and lower ends with insulating heat storage layers 14 interposed therebetween. The holding plates 3 at both ends are joined by metal holding plates 5 at the sides to hold the entire laminate at a constant pressure. 4 is an insulating heat-insulating material that covers the side part of the unit cell group, and 8 is a heat-insulating material that covers the outer surface of the laminate.
Other components include an igniter 6 that emits a flame and ignites the exothermic agent when energized, a vent hole 7 that passes the flame from the igniter, an exterior case 12, an igniter terminal 10, a positive output terminal 9, and a negative There is an output terminal 11. Some conventional thermal batteries have used an insulating resin plate instead of the metal holding plate 3, but it is highly deformed by heat and it is difficult to maintain a constant pressure in the laminate while the battery is active. Ta. Furthermore, if the structure shown in FIG. 1 is adopted, in which metal holding plates 3 are arranged above and below the laminate and these are joined by welding or the like with metal holding plates 5 on the sides, the holding plates 5 are electrically conductive. Since the upper and lower presser plates 3 are electrically connected to each other, the presser plate 3 can be used as either a positive or negative conductive plate.

However, in the conventional thermal battery, a short circuit occurs at the inner circumference of the conduit hole 7 of the metal holding plate 3, causing voltage fluctuations in the early stage of discharge and short-circuit breakdown. It has become clear that the cause of this is as follows. That is, when the thermal battery is activated, the exothermic agent 2 is combusted, but during combustion, the exothermic agent 2 becomes molten for a very short time, and it has been confirmed that when it is combusted in an open state, the molten material becomes spherical. ing. However, in the stacked thermal battery, as shown in FIG. 1, the exothermic agent 2 is sandwiched between the unit cells 1, and only the inner periphery of the vent hole 7 is in an open state. Therefore, when the exothermic agent 2 is burned in the stacked thermal battery,
It became clear that the inner periphery of the vent hole 7, which is the only one in an open state, deforms and flows out into the vent hole 7. This phenomenon was particularly noticeable in the exothermic agent 2 near the metal holding plate 3 at the top or bottom of the laminate, and even filled the vent hole portion of the metal holding plate 3. Furthermore, it was confirmed that the exothermic agent 2 has very good electrical conductivity when melted, and the cause of the above-mentioned trouble is that the exothermic agent 2 has good electrical conductivity in this molten state.
It was determined that this was due to contact between the metal holding plate 3 and the inner circumference of the vent hole 7, causing a short circuit. Such short circuits are concentrated in a very short period at the beginning of discharge because the molten exothermic agent 2 is insulating after solidifying.
The battery may not be activated at all, or a sudden voltage drop may occur immediately after activation, which is a fatal defect for thermal batteries used as emergency power sources.

This invention is a method to solve the above problems.
The metal holding plate 3 is improved as follows. That is, FIG. 2 is an embodiment of the present invention, and a
The metal holding plate 3 is provided with an opening 15 that is concentric with the vent hole 7 and has a larger diameter than the vent hole, and a heat-resistant insulating material is arranged on the inner circumference of the opening portion 15 so as to have the same diameter as the vent hole. In b, not only the inner periphery of the opening 15 but also the outer periphery of the metal holding plate 3 and the surface facing the power generation section are treated with the heat-resistant insulating member 13. As the insulating member 13, a heat-resistant insulating resin such as silicone resin or Teflon resin, or an inorganic heat-resistant insulating material such as asbestos or ceramic can be used. Further, the insulating member 13 can be provided by inserting a molded product or by heat-sealing the molded product to the metal holding plate 3. FIG. 3 shows an example of the use of the metal holding plate 3 according to the present invention, and the numbers in the figure indicate the same components as in FIGS. 1 and 2. Fig. 2a relates to an example of using the metal holding plate shown in Fig. 2a, and this is a case where a heat storage layer 14 is provided between the metal holding plate 3 at the end of the laminate and the terminal unit cell 1. Since the heat storage layer 14 is insulating, it is shown in FIG.
The holding plate shown is effective. Further, FIG. 3b shows the case where the heat storage layer 14 is not present, and in this case, the exothermic agent 2 and the metal presser plate 3 are in direct contact with each other.
A holding plate having a heat-resistant insulating member 13 on one side in contact with the laminate shown in FIG. 2b is effective.

As described above, by using the holding plate provided with a heat-resistant insulating member inside the opening of the present invention, the molten material of the electrically conductive exothermic agent comes into contact with the metal holding plate at the inner periphery of the vent hole. There is no voltage drop at the beginning of discharge due to short circuits, and a highly reliable thermal battery with extremely stable output characteristics can be provided.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional stacked thermal battery;
Figures a and b are cross-sectional views of a holding plate according to an embodiment of the present invention, and Figures 3 a and b are longitudinal cross-sectional views showing a laminated body on the igniter side of a laminated thermal battery constructed using the holding plate of the present invention. It is. DESCRIPTION OF SYMBOLS 1... Unit cell, 2... Exothermic agent, 3... Metal holding plate, 7... Fire vent, 13... Heat resistant insulating member,
15...Opening.

Claims (1)

[Scope of utility model registration request] Unit cells and exothermic agents that are electrically conductive during combustion and melting are stacked alternately, metal holding plates are arranged at both the upper and lower ends, and the metal holding plates are joined by side metal holding plates for processing. This is a thermal battery in which a laminate formed under pressure has a conduit hole in the center thereof through which the flame of an igniter passes, and the metal holding plate is arranged concentrically with the conduit hole and has a conduit hole larger than the conduit hole. 1. A laminated thermal battery characterized by having a large diameter opening and disposing a heat-resistant insulating member having the same conduit hole diameter inside the opening.