JPH0745885Y2 - Thermal battery - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in thermal batteries.

[0002]

2. Description of the Related Art A thermal battery is a battery that uses a molten salt as an electrolyte, and the electrolyte is a non-conductive solid salt during storage and cannot supply electric power to the outside. By burning the electrolyte, the electrolyte is heated to be in a molten state with good electrical conductivity, and electric power can be supplied to the outside.

As a starting mechanism for a thermal battery, an electric ignition type using an ignition ball and a hammer type using a percussion primer have been put into practical use.

Such a thermal battery has the following features and has been put to practical use as a power source for flying objects or an emergency power source. (1) Can be stored for more than 10 years. (2) High-power discharge is possible because active materials with high activity such as calcium, magnesium and lithium can be used. (3) Can be used in a wide temperature range of -55 to + 75 ° C. (4) Strong against vibration and shock.

Generally, the structure of a lithium-based thermal battery has a structure as shown in FIG. In FIG. 1, the electromotive section laminate 1 is configured by alternately stacking the unit cells 2 and the heating elements 3, and an arbitrary number of unit cells 2 are connected in series or in parallel so that a predetermined voltage can be supplied as a whole. Connected to.

The unit cell 2 has a positive electrode layer made of iron sulfide or the like,
It is composed of a separator layer made of a molten mixture and the like, a pellet obtained by pressure molding a negative electrode layer made of a lithium alloy and the like, and a current collector plate.

The heating element 3 is made of iron and potassium perchlorate and is pressure-molded. Battery cover 5 is insulating glass 8
The output terminal 6 and the ignition terminal 7 are provided via the. The ignition terminal 7 is connected to the ignition ball 4 via a lead wire 10. When a predetermined current is applied to the ignition terminal 7, the ignition ball 4 ignites and causes the heating element 3 to burn. 2 becomes a state in which the power can be supplied to the outside by operating.

The output terminal 6 is connected to the electromotive section laminate 1 via a lead wire 10. Reference numeral 11 denotes a heat insulator, and mica, ceramic fiber, or the like is used for each. Reference numeral 12 denotes a battery case, which is welded to the battery cover 5 and has a sealed structure inside.

In the case of a calcium-based thermal battery, the unit cell 2 is composed of a positive electrode layer made of calcium chromate, a two-layer pellet obtained by pressure molding a separator layer made of a molten mixture, and a negative electrode layer made of a calcium plate. Alternatively, zirconium-barium chromate may be used as the heating element, but otherwise the configuration is the same.

[0010]

The unit cell 2 is usually about 1 mm thick and the heating element 3 is thin with a thickness of about 0.4 mm, and the molding pressure of the unit cell 2 and the heating element 3 is considered in consideration of performance. The strength is not sufficient.

Here, the performance means the discharge performance of the unit cell 2 and the burning rate of the heating element 3.

Therefore, when the electromotive portions are stacked or the heat insulator 11 is arranged, the edges of the unit cells 2 and the heating elements 3 are cut off, which causes a leak between the unit cells 2 at the time of discharging, which reduces the discharge capacity or the worst case. In the case of, there is a big problem that it causes a short circuit.

When zirconium-barium chromate is used for the heating element 3, since the heating element 3 is sponge-like, the edges of the heating element 3 will not be chipped.

[0014]

This invention prevents the occurrence of the above problems by making the outer peripheral edge portions of the unit cell and the heating element more rigid from the inside so as to prevent the outer peripheral edge portions of the unit cell and the heating element from being chipped. To do.

[0015]

According to the present invention, the edges of the unit cell 2 and the heating element 3 are not chipped when the electromotive sections are stacked or the heat insulator 11 is arranged, and a leak occurs between the unit cells 2 during discharging. And eliminates the need for a reliable thermal battery.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a top view and a side view showing an example of a unit cell or a heating element used in the present invention. In order to make the outer peripheral edge of the unit cell 2 or the heating element 3 stronger than the inner side, the outer peripheral edge 13 is pressure-molded with a stronger pressure than the inner side.

FIG. 2 shows an example of a process of press-molding the outer peripheral edge portion of the unit cell 2 or the heating element 3 shown in FIG. 1 more strongly.

In FIG. 2, 14 is a protrusion 15 on the outer peripheral edge.
The upper die of the molding die provided with, 16 is the lower die of the molding die, 17
Is a raw material powder of the unit cell 2 or the heating element 3.

When the raw material powder 17 is molded by this molding die, the outer peripheral edge portion 13 of the raw material powder 17 is strongly pressure-molded by the upper mold projections 15 and becomes solid.

[0021]

As described above, according to the present invention, the structure and manufacturing process of the conventional thermal battery are not changed, the edges of the unit cell 2 and the heating element 3 are not chipped during the battery assembly, and the battery is not discharged. In the above, no leak occurs between the unit cells 2, and a highly reliable thermal battery can be supplied.

[Brief description of drawings]

FIG. 1 is a top view and a side view showing an example of a unit cell or a heating element used in the present invention.

FIG. 2 is a view showing an example of a pressure molding process of a unit cell or a heating element used in the present invention.

FIG. 3 is a vertical cross-sectional view showing the configuration of a general thermal battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electromotive part laminated body 2 Unit cell 3 Heating element 13 Outer peripheral edge part

Claims (1)

[Scope of utility model registration request] 1. A thermal battery comprising a unit cell made of a powder molded body and a heating element, wherein the outer peripheral edge portions of the unit cell and the heating element are stronger than the inside.