JP2964768B2 - Thermal battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermal battery.

[0002]

2. Description of the Related Art A thermal battery is a battery using a eutectic salt such as potassium chloride-lithium chloride as an electrolyte. At room temperature, the electrolyte is a non-conductive solid. When the battery is heated to a high temperature, the electrolyte becomes a molten salt having good ionic conductivity, becomes an active state as a battery, and has a property capable of supplying electric power to the outside.

[0003] This type of battery has practically no self-discharge during storage, and exhibits the same discharge characteristics as immediately after production even after long-term storage. The exothermic agent for heating the unit cell is incorporated at the time of manufacture, and the exothermic agent acts when the battery is used, so that the battery can be activated instantaneously, which is convenient for emergency use. Since lithium, which cannot be used in an aqueous electrolyte, is used for the negative electrode, the voltage per unit cell can be increased.
Since it is operated at a high temperature, it has characteristics such as easy electrode reaction and high output characteristics. Therefore, it has been put to practical use as a power source in fields such as various flying objects and induction devices.

[0004] A thermal battery generally has a structure in which a power generating unit in which unit cells and exothermic agents are alternately stacked, an ignition device for starting, a heat insulating material for keeping heat, and the like are hermetically sealed in a metal container.

In use, the igniter is ignited by momentarily applying an ignition current from an external terminal for activation.
The flame ignites and burns the exothermic agent. The combustion heat heats the unit cell, the electrolyte in the unit cell melts, instantaneously generates power, and can supply power to the outside.

[0006]

However, the igniter provided for the start-up is such that the leg holder provided for fixing the leg is formed of a thermoplastic synthetic resin such as styrene resin. It is. Therefore, it was sometimes recognized that by melting with the heat of combustion of the exothermic agent, it flowed to the unit cell portion and partially carbonized, thereby forming an electric bridge between the unit cells to induce voltage fluctuation.

As one of the methods for solving this problem, there is a method in which the leg line holder of the igniter is made of a ceramic molded body, but there is a disadvantage that the cost becomes several times.

An object of the present invention is to solve this problem and to provide a low-cost thermal battery that does not cause voltage fluctuation.

[0009]

In order to achieve this object, a thermal battery according to the present invention comprises a protective layer made of a thermosetting resin at an exposed portion of a leg holder formed of a thermoplastic resin mounted on the thermal battery. The provision of the provided igniter prevents melting outflow due to the heat of combustion of the exothermic agent and eliminates voltage fluctuation.

[0010]

With this configuration, by protecting the holder with the thermosetting synthetic resin, the heat resistance is improved, the melting, outflow, and carbonization of the thermoplastic resin are eliminated, and the induction of voltage fluctuation is prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermal battery according to an embodiment of the present invention will be described below in detail with reference to the drawings.

In FIG. 2, reference numeral 12 denotes an ignition charge, reference numeral 13 denotes an electric bridge wire, reference numeral 14 denotes a holder made of styrene resin, which holds 15 legs. Although this is the same as a conventionally used ignition device, the present embodiment is characterized in that the exposed portion of the holder 14 is protected by a thermosetting resin, and the details will be described later.

In FIG. 1, reference numeral 1 denotes a unit cell (not shown), a current collector plate composed of a steel plate on both sides of a Ca negative electrode and an electrolyte layer mainly composed of KCl-LiCl eutectic salt, and a positive electrode layer mainly composed of CaCrO _4. In this configuration, power is not generated, but the power is not generated. However, when heated, the electrolyte melts to generate power, and the power is supplied to the outside through the positive and negative airtight terminals 7 and 8. Reference numeral 2 denotes an exothermic agent mainly composed of Zr and BaCrO _{4. When the} igniter 3 is momentarily energized and ignited through the starting terminal 4, the flame is guided to the heat conducting hole 5, ignited and burned, and the unit cell 1 is fired. Are arranged on both sides of the unit cell 1 so as to be heated. The heat insulating layer 6 is made of inorganic paper or the like, and is provided to keep the temperature of the power generation unit and to prevent thermal damage to peripheral equipment of the thermal battery. Reference numeral 9 denotes a metal outer container, which includes a case 9a and a lid 9b, and is hermetically sealed at a fitting portion.

The igniter 3 described above is attached to the inside of the outer container lid 9b via an insulating plate 10 made of mica.
It is connected to the starting terminal 4. The difference from the conventional case is that after attaching to the outer container lid 9b, the exposed portion of the thermoplastic resin holder 14 shown in FIG. 2 is protected by applying a well-mixed adhesive obtained by adding a curing agent to the epoxy resin. That is, the layer 11 is formed. Holder 14 from this
Troubles such as voltage fluctuations due to melting, outflow, and carbonization of steel were eliminated, and stable discharge performance was obtained.

The thickness of the protective layer 11 was determined as a result of an experiment.
It has been confirmed that the effect is about 0.1 mm,
0.3 mm or more is desirable.

Further, there is an advantage that the cost for performing this procedure is small in both the material cost and the processing cost.

[0017]

As is apparent from the above description of the embodiments, the thermal battery according to the present invention is an industrially significant invention which can provide a thermal battery with stable discharge performance without increasing the cost much. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of a thermal battery according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of an ignition device used in a conventional thermal battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Unit cell 2 Heating agent 3 Ignition device 6 Heat insulation layer 9 Metal outer container 11 Thermosetting resin protective layer

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuya Omichi 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) H01M 6/36 F42B 3/12

Claims (1)

(57) [Claims] 1. A thermal battery in which a power generating unit in which unit cells and a heating agent are alternately stacked, a heat insulating layer for keeping the power generating unit warm, and an igniter for igniting the heating agent are sealed in a metal outer container. A thermal battery comprising the igniter, wherein the leg holder is a thermoplastic resin molded body, and the exposed portion is protected by a thermosetting resin.