JPH02299161A - Thermal battery - Google Patents

Abstract

PURPOSE:To reduce the resistance difference between lead sections of laminated blocks to the utmost, minimize the increase of a battery in the outer diameter direction, and simplify lead welding by forming a relay lead plate into a concentric circular shape with the outer shape of a generating section laminated body, providing the same number of opening sections as block leads at corresponding positions of the relay lead plate, and welding them at these positions. CONSTITUTION:A relay lead plate 1 is made sufficiently wider than block leads, the relay lead plate l concentrically circular with the outer shape of a laminated body has a shape with a wide area surrounding the laminated body, and the current value of the relay lead plate 1 per unit area is reduced. The same number of opening sections 3 as block leads are provided at corresponding positions of the relay lead plate 1, and they are welded at these positions. This welding is performed at multiple positions of the relay lead plate 1, thus the current borne by the welded section of the relay lead plate 1 is reduced, and the splitting of the relay lead plate 1 due to the heating of the welded section is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a lithium/iron disulfide thermal battery, and more particularly to an improvement in internal lead portions when internally connected in parallel.

BACKGROUND TECHNOLOGY A thermal battery is inactive at room temperature, but becomes active when heated to a high temperature and can supply power to the outside, and is a type of storage battery. Therefore, even after storage for 6 to 10 years or more, the battery characteristics remain the same as they were immediately after manufacture, so they are used as an emergency power source. In addition, since it is operated at high temperatures, electrode reactions can easily proceed, so there is little polarization, so it has excellent large current discharge properties, and when desired, it has features such as instantaneous power extraction when a start signal is input.

However, in recent years, higher output has been desired, and in many cases, particularly large current discharge is required. In this case, the conventional thermal battery has disadvantages such as a decrease in output voltage due to the internal resistance of the lead plate inside the battery, and furthermore, the lead plate may break due to excessive heat generation of the lead plate.

Research that has been carried out to overcome this problem has been limited to some extent by stacking multiple narrow battery internal leads to increase the cross-sectional area of the leads and reducing lead resistance. Improvements were needed.

Problems to be Solved by the Invention However, in the conventional example described above, by stacking a plurality of lead plates, the thickness of the lead weld increases, and the reliability of the welding process cannot be easily ensured. In addition, the increase in the thickness of the lead part causes an increase in the dimensions of the battery in the outer diameter direction, creating a gap between the battery case and the laminate, which may disrupt the thermal balance or cause the battery to become larger. A problem arose.

In order to solve the above-mentioned conventional problems, the present invention connects a power generation unit stack consisting of a plurality of stacked blocks in parallel,
By focusing on the shape of the relay lead plate for parallel connection, we aimed to minimize the difference in lead resistance between each laminated block, reduce the increase in the battery's outer diameter, and simplify lead welding. purpose.

Means for Solving the Problem In order to solve this problem, the relay lead plate of the present invention has a shape that is sufficiently wider than the block lead and has a wide area where the lead plate, which is concentric with the outer shape of the laminate, surrounds the laminate. Reduce the current value per unit area of the lead plate. Also, the same number of openings as the block leads are provided at corresponding locations on the relay lead plate, and welding is performed at these locations. Since this welding is performed at a plurality of positions on the relay lead plate, the current borne by the welded portion of the lead plate is reduced, and there is no risk of the lead plate being cut due to heat generation at the welded portion. Furthermore, due to the presence of such multiple welds, the lead plate firmly adheres to the stacked unit cell group, and due to the shape of this lead plate, the process of inserting the stacked unit battery group with the lead plate attached into the battery case is also difficult. becomes easier,
Man-hours can also be reduced.

Function: If this relay lead plate is used to create a thermal battery, it is possible to avoid the drop in output voltage due to the difference in length of the internal battery lead when outputting a large current, as well as the breakage of the lead weld due to excessive heat generation. . Further, the shape of the lead plate is circular and concentric with the outer diameter of the laminated block, and is shaped along the side surface of the laminated block, so that the increase in the outer diameter direction of the battery is small and the battery does not become large. Furthermore, the laminated blocks are connected in parallel through lead plates, and the lead plates and the laminated body are firmly attached by welding the terminal leads from this lead plate and the multiple laminated blocks, and the laminated body is inserted into the battery. It also becomes easier.

As described above, by using this lead plate in the case of large current output, the battery can be manufactured easily and the battery current output can be stably obtained.

Embodiments Below, embodiments of the present invention will be explained using FIGS. 1 and 2. FIG. 1 shows a relay lead plate of the present invention, and FIG. 2 shows a battery lid and a lead plate for the lid.

In FIG. 1, numeral 1 is the lead plate main body of the present invention, which is made of a metal that is a good conductor. Its shape was a circular shape concentric with the outer shape of the laminated block, and in this example, the laminated body was a cylinder.

An opening 3 is provided in the lead plate body, and the terminal lead plate of the laminate is taken out from this opening 3. A welding lead (I) 4 provided around the opening 3
This has the effect of facilitating welding of the terminal lead plate from the laminate and strengthening the firm adhesion between the lead body and the laminate.

FIG. 2 shows the constructed battery lid.

This battery cover has a plurality of lead plates, and the positive cover lead plate 7 is connected to the positive output terminal 6, and the negative cover lead plate 8 is connected to the negative output terminal 6. This allows for easy welding with the provided welding lead (■) 2.

FIG. 4 shows a diagram in which the lead plate of the present invention is integrated with a laminate. Further, FIG. 3 shows parallel connections of the laminate. The laminate uses iron disulfide as an active material and a molten salt electrolyte Lie/-
A positive electrode mixture layer 11 obtained by homogeneous mixing with KCl, and L
An electrolyte layer 12 made of an MgO binder impregnated with iC1-KCl, and a negative electrode 13 made of an integral mixture of pure lithium and iron powder or a lithium-aluminum alloy layer.
A stacked block obtained by alternately stacking a unit cell 14 made of the above and a heat generating agent 10 made of a homogeneous mixture of potassium perchlorate and iron powder is arranged in parallel so as to have three output parts: &, b, and a. It is connected to the

Although the above description has been made regarding the positive electrode, the negative electrode also has the same basic structure as the positive electrode, and has a laminate sandwiched between two relay lead plates.

Next, the results of investigating the effects of this example will be described. The diameter of the unit cell is φ60 fl, and the power generating section is made up of 6 unit cells connected in series as 1 block, 4 blocks are connected in parallel, the discharge current is 60 μm per block, and a discharge test is conducted to obtain an output current of 240 μm. Also, the average operating voltage is 1.8 v secμ.

The discharge characteristics are shown in FIG. 5, and the mark in the figure indicates the discharge curve of the example of the present invention. B shows a conventional example, in which each battery block connected in parallel has one lead plate with a width of 10n.

In battery B, the lengths of the lead plates connected in parallel, that is, the distances from each block to the battery lid, are different, so the resistance of each lead plate is different. For this reason, the initial discharge voltage is 10V, but as time passes, the load differs between each block and the discharge density is not uniform, leading to differences in the discharge current and shortening the battery life. there were.

On the other hand, in the case of the present invention, the average operating voltage is 1.84 V/-U, which is 0.1 V/cell higher than the same voltage in the conventional example, and the discharge voltage curve is also flat. Further, since the lead plate area of the present invention is sufficiently wide, there is no difference in the discharge current value of each block, and the battery life is extended.

Effects of the Invention As is clear from the above explanation, in the case of large current output, the power generation section is not only connected in parallel to a plurality of battery blocks, but also by using the relay lead plate of the present invention. One positive electrode and one negative electrode each having a circular shape concentric with the outer shape of the battery group.
By placing two relay lead plates along the sides of the laminated block, welding with the output terminals from the laminated block can be easily achieved by providing an opening in the lead plate, and the welding area can be safely welded. A battery with stable performance and output current can be obtained.

Furthermore, since this relay lead plate is in close contact with the stacked battery group, it is easy to manufacture.

[Brief explanation of the drawing]

Fig. 1 is a front three-dimensional view of the relay lead plate of the present invention, Fig. 2 is a perspective view of the battery cover used in the present invention, Fig. 3 is an internal wiring diagram of the stacked power generation unit, and Fig. 4 is the relay lead of the present invention. FIG. 5 is a partially broken perspective view showing an example in which the plate and the laminate are integrated, and FIG. 5 is a discharge curve diagram of an embodiment of the present invention and a conventional example. 1... Relay lead plate, 2... Welding lead (II), 3... Opening part, 4...
Welding lead (It), 7... Positive electrode lid lead plate, 10... Heat generating agent, 14... Unit cell,
16...Battery cover. Name of agent: Patent attorney Shigetaka Awano and one other person (-
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Claims (1)

[Claims] A plurality of laminated blocks each consisting of at least a unit cell 14 as a power generation element, a heat generating agent 10 as a heating element for the unit cell, and block lead parts a, b, and c for extracting electric power are stacked in the vertical direction. The relay lead plate 1 is electrically connected to a battery lid 16 having a lid lead plate 7, and the relay lead plate 1 is electrically connected to a battery lid 16 having a lid lead plate 7, and the battery lid 16 is inserted into a battery case and sealed. In the battery, the relay lead plate has a concentric shape with the outer shape of the power generation unit laminate, and has an opening 3 in a portion corresponding to the block lead plate, and a welding lead (II) 4 around the opening 3. At the same time, a welding lead 2 is attached to the part corresponding to the positive output lead plate.
A thermal battery characterized by having: