JPS62126561A - Thermal battery - Google Patents

Abstract

PURPOSE:To quicken activation speed even in a large thermal battery by arranging a plurality of fire conducting holes for igniting heating material in a thermal battery in which unit cells and heating materials are alternating stacked. CONSTITUTION:A plurality of fire conducting holes 6'' is formed through stacked cells 8 and heating materials 7. Zn/BaCrO4 is filled in the fire conducting holes 6'' as fire conducting chemicals. Each of fire conducting material sheets 9, 9' is used in the upper part and the lower part of stacked cells. When instant current is applied across ignition terminals 11 of an igniter 10, the igniter 10 ignites, and the fire conducting material 9 catches fire and heating materials 7 catches fire through the fire conducting chemicals in the fire conducting holes 6''. Thereby, even in a large thermal battery, activation speed can be quickened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thermal battery obtained by alternately stacking unit cells and a heat generating agent, and provides a thermal battery that is activated quickly.

Conventional thermal batteries use molten salt as an electrolyte, and cannot conduct current at room temperature, but when heated to high temperatures, the electrolyte melts and becomes extremely conductive, making it possible to discharge at large currents. It becomes possible. For this reason, thermal batteries do not self-discharge when unused and can be stored for long periods of time, making them excellent as highly reliable emergency high-output power sources. In particular, thermal batteries that use discharging iron as the main material and lithium or lithium alloy as the negative electrode have a high energy density and have little self-discharge during operation, so comparisons where the discharge time can last several tens of minutes or more Development is also progressing for long-term use.

A thermal battery holds a heat generating agent inside, and when used, the heat generating agent is ignited to instantaneously heat the inside to the operating temperature and activate the battery. Zr is used as such exothermic agent.
/BaQ-On type sheet exothermic agent and Fe/KCl0+
Pellet exothermic agents of this type are well known. Sheet-shaped exothermic agents are made by dispersing exothermic agent particles in water with inorganic fibers such as asbestos, and then straining them into sheet shapes.They are lightweight, generate a high amount of heat, and burn quickly, but they are easily ignited and are inconvenient to handle. It has the disadvantage of being. On the other hand, pellet-shaped exothermic agents are exothermic agents that have been molded under pressure, and have a low calorific value per weight and a slow burning rate, but they have high mechanical strength and are difficult to ignite, making them easy to handle. In addition, since it itself has conductivity, it has the advantage that a connecting plate between the unit cells is unnecessary, and has been widely used in recent years.

PROBLEM TO BE SOLVED BY THE INVENTION Due to the advantages of thermal batteries, such as high reliability, long shelf life, and high energy density, there is a need for the development of larger thermal batteries with higher capacity and higher power.

However, as thermal batteries have become larger, a drawback has arisen in that the speed at which the potential rises during use, that is, the speed at which they are activated becomes slow.

When the fuse is ignited using an ignition means such as a hammer A5 electric detonator during activation of the thermal battery, the fuse instantly combusts and releases sufficient thermal energy to ignite the exothermic agent. The exothermic agent ignited on a part of the surface releases thermal energy and self-combusts, igniting the exothermic agent in the vicinity. In this way, a combustion reaction propagates, burning all the exothermic agent and heating the thermal cell from within to its operating temperature. Only when the inside of the thermal battery is heated to a high temperature and the electrolyte melts does it become possible to discharge. The melting of the electric rR voltage is observed as the upper bound of the potential of the thermal battery.

As thermal batteries have become larger, the exothermic agents have also become larger, and the time from ignition of the fuse to the end of combustion of all the exothermic agents has become longer, resulting in a decrease in the activation speed of thermal batteries. ,
This effect was particularly significant when a pellet-shaped exothermic agent with a slow burning rate was used.

Means for Solving the Problems The present invention solves the above-mentioned problems associated with the increase in the size of thermal batteries. A fuse to ignite the ? I
r! It is characterized by the fact that 1G Ku is high.

Function In the present invention, since the exothermic agent is ignited by the plurality of fuse holes, the exothermic agent can be burned in a short time, and the activation time required as the thermal battery becomes larger can be reduced. It became possible to improve the delay.

EXAMPLE An example in which the present invention is applied to a lithium/iron disulfide thermal battery will be described below.

FIG. 1 is a cross-sectional view of a unit cell for a thermal battery according to the present invention. In the figure, 1 is a negative camellia layer, which contains lithium impregnated into a porous body, lithium-aluminum alloy, lithium-silicon alloy, lithium-boron alloy, etc. A lithium alloy is used. 2 is an electrolyte layer in which a molten salt electrolyte whose fluidity is reduced with ceramic powder such as MOO or Y203 is used.

3 is a positive electrode layer, which is mainly composed of iron distributide (FeSz) and is a mixture of an electrolyte and a binder powder for holding the electrolyte. 4 is a negative electrode current collector plate, 5 is a positive electrode current collector plate, 6
are a plurality of fuse holes provided in the unit cell.

FIG. 2 is a cross-sectional view of the exothermic agent. Reference numeral 7 is a pellet-shaped exothermic agent, which has a plurality of fuse holes 6'.

The pellet-shaped exothermic agent 7 is made by press-molding a heated mixture of an oxidizing agent and a reducing agent into a strong plate shape, and is easy to handle because it has high mechanical strength and is difficult to catch fire. Such exothermic agents include Fe/KClO4, Nl/KClO4, F
e/KBrO3, Ni/K I O3, r/K CI
Combinations such as 03 can be used, but here HaFe/
A KClO2-based exothermic agent was used.

FIG. 3 is a sectional view of a thermal battery of the present invention in which the above-described unit cell and exothermic agent are laminated. , 8 are unit cells each having four layers, and are alternately stacked with pellet-like exothermic agents 7. 6
A plurality of fuse holes are formed in the stacked unit cells 8 and the exothermic agent 7. Inside the fuse hole 6'' is Zl''/Ba c+-04 as a fuse for igniting the exothermic agent 7.
Filled with exothermic agent.

9 and 9' are sheets of fuse for igniting the fuse in each fuse hole.
I used one piece at a time. 10 is an ignition tool, and an ignition terminal 11
When an instantaneous current is applied, the igniter 10 ignites, immediately igniting the fuse 9 and igniting the exothermic agent 7 via the fuse in the plurality of fuse holes 6pa. 12 is a positive terminal, and 13 is a negative terminal.

14 is a heat insulating agent for insulating and moisturizing the inside of the thermal battery;
15 is a battery container.

A thermal battery was constructed by stacking 17 sets of disc-shaped unit cells each having a diameter of 8ofl111 and a heat generating agent. The thermal battery of the present invention, which has four fuse holes arranged on a concentric circle with a radius of 20 mm, has an active seven-hour period of 0.4 hours until the terminal voltage reaches 24 V after the igniter is energized.
It was 5 seconds. On the other hand, the activation time of a conventional thermal battery with only one fuse hole in the center was 0.85 seconds.

Effects of the Invention According to the present invention, even in large thermal batteries, the activation time can be shortened by providing a plurality of fuse holes.
Furthermore, even with exothermic agents that are difficult to ignite, there is no risk of ignition failure because ignition is performed simultaneously from multiple locations.

[Brief explanation of drawings]

Figure 1 is a sectional view of a unit cell constituting the thermal battery of the present invention;
The figure is a cross-sectional view of the exothermic agent, and FIG. 3 is a cross-sectional view of the thermal battery of the present invention. 6.6', 6°゛...Muse hole 7...Exothermic agent 8...Battery λ7
2' leading large hole wide hole

Claims (1)

[Claims] In a thermal battery in which a unit cell and a heat generating agent are alternately stacked,
A thermal battery characterized by having a plurality of fuse holes for igniting a heat generating agent.