JPH0672157U - Thermal battery - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent chipping of the outer peripheral edge of the unit cell and the heating element when stacking the electromotive section and in disposing the heat insulator in the thermal battery including the unit cell made of powder compact and the heating element. This solves the problem of leakage between the unit cells during discharging and supplies a highly reliable thermal battery. [Structure] The outer peripheral edge portions of the unit cell and the heating element are made stronger from the inside.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to improvements in thermal batteries.

[0002]

[Prior art]

 A thermal battery is a battery that uses molten salt as an electrolyte.The electrolyte is a non-conducting solid salt that cannot be used to supply electric power to the outside during storage, but the electrolyte is generated by burning the heating element built into the battery. Is heated to a molten state with good electrical conductivity, so that electric power can be supplied to the outside.

As a starting mechanism of 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 supply for a flying vehicle or an emergency power supply. (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 the figure, 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 a column.

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

The heating element 3 is made of iron and potassium perchlorate and is pressure-molded. The battery cover 5 is provided with an output terminal 6 and an ignition terminal 7 via an insulating glass 8. The ignition terminal 7 is connected to the ignition ball 4 via the 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 is 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 made of a calcium plate. Zirconium-barium chromate may be used for the heating element instead of the layer, but otherwise the same configuration.

[0010]

[Problems to be solved by the device]

 Normally, the unit cell 2 has a thickness of about 1 mm per sheet, and the heating element 3 has a thickness of about 0.4 mm, which is thin, and the molding pressure of the unit cell 2 and the heating element 3 is determined in consideration of the performance. Is not enough.

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 cell 2 and the heating element 3 are chipped, which causes a leak between the unit cells 2 at the time of discharge, which may reduce the discharge capacity. Has a big problem that it causes a short circuit in the worst case.

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

[0014]

[Means for Solving the Problems]

 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 to prevent chipping of the outer peripheral edge portions of the cell and the heating element.

[0015]

[Action]

 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 there is no leakage between the unit cells 2 during discharging. And to provide a highly reliable thermal battery.

[0016]

【Example】

 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 step of more strongly press-molding the outer peripheral edge portion of the unit cell 2 or the heating element 3 shown in FIG.

In FIG. 2, 14 is an upper die of a molding die provided with protrusions 15 on the outer peripheral edge, 16 is a lower die of the molding die, and 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, and the edges of the unit cell 2 and the heating element 3 are not chipped when the battery is assembled, and the discharge is performed. Occasionally, 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.