JPH0515319U - Thermal battery - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to ensure distinction between unused thermal batteries and used thermal batteries. [Structure] On a surface of a thermal battery container (1), a temperature sensitive body (2) which is irreversibly discolored by temperature rise is provided, and the surface is covered with a transparent resin (3) having a heat retaining effect.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a thermal battery that has a built-in heat generating agent inside the battery and ignites the heat generating agent when the battery is used to heat the inside of the battery to a high temperature to activate the battery. To ensure.

[0002]

[Prior Art]

 A thermal battery is a battery that uses a molten salt as an electrolyte, and since the electrolyte is a non-conductive solid salt during storage, it is in an inactive state, but the built-in heating agent is burned to By heating the inside to a high temperature, the electrolyte is melted and becomes conductive and activated.

A thermal battery is a type of storage battery that has almost no self-discharge during storage, can be stored for a long period of time, and can be instantly activated when necessary. It is also a high energy density battery that can be used under a wide range of environmental temperatures such as -55 to 100 ° C. Because of these many features, thermal batteries are indispensable as power sources for missiles, rockets, and other flying vehicles, and various emergency power sources.

It is well known that calcium is used for the negative electrode and calcium chromate is used for the positive electrode as the active material of the thermal battery. For higher capacity and higher output, lithium or lithium alloy is used for the negative electrode and lithium is used for the positive electrode. Thermal batteries using sulfides and oxides have also been developed.

As the sulfide of the positive electrode active material, iron disulfide that is stable at high temperature, sulfides of nickel, chromium, cobalt, copper, tungsten, molybdenum, and the like, and sulfides of the fibril phase containing these metals are also available. It can be used.

[0006] LiCl-59 mol% and KCl-41 mol% eutectic salts are generally used as electrolytes. A ternary molten salt electrolyte such as the Li Br-LiCl-LiF system is also used. The electrolyte used is one in which lithium, which is a negative electrode, is mixed with an insulating powder such as magnesium oxide, boron oxide, or zirconium oxide, which has corrosion resistance, so as to lose fluidity. The electrolyte layer not only acts as an ion conductor during thermal battery operation, but also acts as a separator for the positive and negative electrodes.

As the heat generating agent, a molded product of a mixture of iron powder and potassium perchlorate is used by being laminated alternately with the unit cell. When the heating agent is ignited when the battery is activated, it generates heat due to a redox reaction and heats the inside of the battery to the operating temperature. This exothermic agent contains iron in excess of the amount required for the exothermic reaction, has high conductivity even after the exothermic reaction, and acts as a connecting body between adjacent unit cells.

[0008]

[Problems to be solved by the device]

 A thermal battery generates an electromotive force for the first time by an activation operation that ignites a built-in heat generating agent, so it is not possible to distinguish used products from unused products by measuring the terminal voltage like other primary batteries. is there.

[0009] Conventionally, a proposal has been made that a surface of a thermal battery container is coated with a paint that irreversibly changes color depending on temperature, and that the activated state is indicated by the change in the color (Japanese Patent Publication No. 50-11056).

In the activated thermal battery, the inside of the battery is heated to the operating temperature by the built-in heat generating agent, and the container temperature also gradually rises. When the temperature of the surface of the thermal battery container reaches a certain value, the paint irreversibly discolors and does not return to the original color even when the temperature drops, indicating that the thermal battery has been activated.

However, depending on the use conditions of the thermal battery, the temperature of the coating material on the container surface does not rise sufficiently, and there is a drawback that it does not discolor even though it has been activated.

Thermal batteries are fixed to the equipment by inserting the block into a hollowed hole or tightening with a fixing band, but if the paint surface is in contact with the inner wall of the block or the fixing band, The temperature sometimes did not rise to the specified value required for discoloration. In addition, when used outdoors, the temperature of the coating could not rise sufficiently due to the surface of the coating getting wet with water or strong winds.

[0013]

[Means for Solving the Problems]

 The present invention improves on the conventional drawbacks by providing a temperature-sensitive body on the surface of a thermal battery container that irreversibly changes color when the temperature rises, and coats the surface with a transparent resin that has a heat-retaining effect. It is a feature.

A temperature-sensitive body is one whose color and appearance change irreversibly due to chemical changes or physical changes when heated above a certain specified temperature, and it is possible to use paint or sheet-shaped ones. is there. Apply it to the surface of the thermal battery container or stick it to it and observe the change in color and surface shape to detect that it has been heated above the specified temperature.

[0015]

[Action]

 Since the surface of the temperature sensor of the present invention is protected by a transparent resin that has a heat retaining effect, it is in contact with low temperature or large heat capacity such as a block or band for fixing the thermal battery. However, the color changes normally. Moreover, even when used outdoors, the surface of the temperature sensor is protected, so it is stable against water wetting and wind, and because it is transparent, it does not interfere with observation of the temperature sensor.

[0016]

【Example】

 FIG. 1 is a cross-sectional view of a lithium / iron disulfide thermal battery manufactured as an embodiment of the present invention. A thermal battery container 1 has a negative electrode terminal 4 for taking out an electric current, a positive electrode terminal 5, and an ignition terminal 6 for activation on the upper part thereof. By energizing the ignition terminal 6 with an ignition current, the thermal battery is activated and an electromotive force is generated between the negative electrode terminal 4 and the positive electrode terminal 5. The thermal battery of Example has a cylindrical shape with an outer diameter of 51 mm and a height of 65 mm. Reference numeral 2 is a temperature sensitive body provided in the center of the side surface of the thermoelectric cell container, and 3 is a transparent resin having a heat retaining effect to protect the surface.

Thermo Paint No. 10 (Taika Sangyo Co., Ltd.) was used as the temperature sensitive body 2 of the example. Thermo Paint No. 10 is an irreversible temperature indicator paint that changes from light reddish purple to bluish purple when heated above 130 ° C and retains that color even when the temperature drops.

As the transparent resin 3, a 0.8 mm-thick FEP heat-shrinkable tube was used on the entire side surface of the container. The transparent resin 3 needs to cover at least the surface of the temperature sensitive body, and a sheet-shaped resin may be attached to the surface of the temperature sensitive body, or a thermosetting resin may be potted.

In order to investigate the effect of the present invention, a thermal battery was fixed on an aluminum block base and activated.

FIG. 2 is a perspective view showing the thermal battery in the test state. Reference numeral 7 is a block base made of aluminum, which is hollowed out so that the center portion is aligned with the radius of the thermal battery, and the thermal battery 8 is fixed to the block base 7 with a fixing band 9 downward so that the temperature-sensing body portion contacts the block. ing.

The thermal battery of the present invention was activated at a low temperature of −45 ° C., and after cooling, it was removed from the block stand, and when the temperature sensitive body was observed, it turned blue-purple. A similar test was conducted on a conventional thermal battery in which the temperature sensitive body was not covered with a transparent resin, but no discoloration of the temperature sensitive body was observed. The temperature sensor of conventional thermal batteries is in direct contact with the block base, and it is thought that the heat escaped from the surface did not raise the temperature to the specified temperature required for discoloration.

The transparent resin 3 used in the present invention may be translucent to the extent that the color of the temperature sensitive body can be observed. Also, the required heat retaining effect depends on the type of thermal battery and the test conditions, but for ordinary resins, a thickness of 0.3 mm or more is sufficient. As a matter of course, the resin used must have heat resistance higher than the surface temperature of the battery container after activation.

[0023]

[Effect of the device]

 As described above, the present invention ensures the distinction between an unused thermal battery and a used thermal battery, and there is no restriction on the mounting method or mounting position, and the surface of the temperature sensing element is protected so that there is no damage. It does not stick easily and can be used under harsh conditions.

[Brief description of drawings]

FIG. 1 is a side view of a thermal battery showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a test state of the thermal battery of the present invention.

[Explanation of symbols] 1 thermal battery container 2 temperature sensitive material 3 transparent resin 4 negative electrode terminal 5 positive electrode terminal 6 ignition terminal 7 block base 8 thermal battery 9 fixed band

Claims (1)

[Scope of utility model registration request] 1. A thermosensitive battery container (1) is provided with a temperature sensitive body (2) which is irreversibly discolored by a temperature rise on the surface thereof, and the surface is covered with a transparent resin (3) having a heat retaining effect. And a thermal battery.