JPH038262A - Laminated battery - Google Patents

Abstract

PURPOSE:To increase a production yield and improve drop strength by laminating multiple layer tablets via ion blocking electrodes, and forming the ion blocking electrode with a conductor made of a protruded curved plate with a spring property. CONSTITUTION:A positive electrode 4, a separator material 5 and a negative electrode material 6 are pressurized and integrally molded to form a layer tablet. The above molded body is mounted in a battery container 9 welded with a current collecting net 7 and mounted with a gasket 8, then an electrolyte 10 is fed for impregnation. An ion blocking electrode 12 with a shape machined into a protruded curved face is put on the layer tablet in the battery container 9, and a layer tablet is put on the electrode 12. The second and following tablets are put so that the face with the polarity different from that of the preceding tablet in contact with the electrode 12 is brought into contact with the electrode 12, and the electrolyte 10 is fed. Finally, a battery container 9 and a cover 11 are caulked and sealed. The face pressure of spring stress is applied to the tablet, and the tablet can be fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a stacked battery. More specifically, the present invention relates to improvements in ion blocking electrodes disposed between battery elements of a stacked battery.

(B) Conventional technology Conventional laminated batteries are manufactured by impregnating multiple sides of a three-layer tablet-shaped battery element (hereinafter referred to as battery element) with an electrolytic solution in a battery container, which consists of a positive electrode material, a separator material, and a negative electrode material. The elements are stacked sequentially with a planar ion blocking electrode interposed between them.
It is made by enclosing it.

(c) Problems to be Solved by the Invention The conventional stacked battery described above has a low manufacturing yield due to insufficient electrical contact between the planar ion blocking electrode and the battery element. There is a problem of insufficient strength (drop strength) against +*G (impact).

This invention was made to solve these problems, and improves the electrical contact between the ion blocking electrode and the battery element to improve the manufacturing yield and improve the drop strength of the stacked battery. With the goal.

(d) Means for Solving the Problems According to the present invention, a plurality of layered tablets in which a positive electrode material, a separator material, and a negative electrode material are laminated and pressurized on the head,
The batteries are laminated with an ion blocking electrode interposed therebetween, impregnated with an electrolytic solution if necessary, and sealed in a battery container, and the ion blocking electrode is made of a conductor in the shape of a convex curved plate with spring properties. A stacked battery is provided.

Hereinafter, a stacked battery using a three-layer tablet-shaped battery element using a hydrogen storage alloy as the negative electrode active material will be described as an example, but the present invention is not limited to this example.

First, the ion blocking electrode of the present invention will be explained in detail. This ion blocking electrode collects electrons generated by a chemical reaction within the layered tablet at a predetermined potential difference, prevents the movement of ions between the tablets, and also prevents the movement of ions between the layered tablets due to an impact such as a fall. It is used to apply surface pressure that can prevent easy lateral movement, and has insulating properties against ionic species present in the electrolyte and conductivity against electrons.
I Electrolytes Suitable are materials that do not react, are impermeable to liquids, and have elasticity, such as conductors such as metals, conductive polymer compounds, conductive ceramics, conductive plastics, and conductive rubber. For example, as shown in FIGS. 8 to 10, it can be formed into a convex curved plate shape with spring properties.

Specifically, the material for the ion blocking electrode is:
For example, synthetic rubber in which nickel, titanium, or carbon-based conductive agents are dispersed can be used.

The ion blocking electrode made of the conductor in the shape of a convex curved plate with spring properties is made by appropriately selecting the material for the ion blocking electrode, for example, by drawing or injection molding the planar material. It can be produced by mold forming processing such as extrusion molding or compression molding, cutting processing, or coating film formation processing on a convex curved plate-shaped base material with spring properties such as metal or ceramics. This ion blocking electrode! Assembling the stacked battery using electrodes includes:
The steps of placing the layered tablet, placing the convex curved plate-shaped ion blocking electrode on top of it, and placing the layered tablet again on top of it are repeated as appropriate, and this is pressed to remove the ion blocking electrode. This can be carried out by using a pressed body of a conductor in the form of a springy convex curved plate which has been spring-deformed from a convex curved plate shape to a flat plate shape and sealed in this battery container.

This ion blocking electrode as a pressing body of a convex curved plate-shaped conductor having spring properties can be brought into sufficient electrical contact with the adjacent layered tablet due to the spring stress of this electrode, and the layered tablet Sufficient surface pressure can be applied to prevent lateral movement due to impact.

Next, the structure of the stacked battery of the present invention will be explained in more detail. In the stacked battery of the present invention, an electrolytic solution may be used as a medium capable of transferring electrons generated by the chemical reaction of the layered tablet to and from the ion blocking electrode or the current collector, or a solid electrolyte may be used.

First, a stacked battery manufactured using an electrolyte will be described.

The layered tablet, which generates electrons with a predetermined potential difference and constitutes the stacked battery of the present invention, is formed by laminating a positive electrode material, a separator material, and a negative electrode material in this order. The positive electrode material includes a positive electrode active material, a conductive agent, and a binder. As a positive electrode active material,
Examples of the oxidizing agent 1 include manganese dioxide, nickel oxide, tungsten dioxide, lead dioxide, and molybdenum dioxide, with manganese dioxide and nickel oxide being preferred.

The above-mentioned conductive agent is an electronically conductive substance added to ensure electronic conductivity in the positive electrode material, and examples thereof include acetylene black, graphite, carbon black, nickel powder, etc., with acetylene black and graphite being preferred. be. The above-mentioned binder is a substance added to improve the binding properties of the above-mentioned two kinds of powders, and examples thereof include carboxymethylcellulose, polytetrafluoroethylene, carboxymethylcellulose salt, polyvinyl alcohol, polyethylene, agar, methylcellulose, etc. Can be mentioned. The conductive agent and the binder are usually mixed in the positive electrode material in an amount of 3 to 20 weight percent. The separator agent includes a decomposition support and, if necessary, a binder.

The electrolyte support preferably has insulating properties and can support the electrolyte, such as silicon dioxide and aluminum oxide. As this binder, the same binder as that used for the positive electrode material can be used.

This binder is added in an amount of 40 parts by weight or less to 100 parts by weight of the electrolytic solution support, if necessary.

The negative electrode material is a hydrogen storage alloy as a negative electrode active material, for example, T r xN i (1≦X≦2)TiFe that stores hydrogen.
, LaNi5, MmN i s, etc. are used. The conductive agent and the binder may be the same as those for the positive electrode material, and the amounts thereof are usually 20 parts by weight or less, respectively, in the negative electrode material.

The positive electrode material, separator material, and negative electrode material are, for example, as shown in FIGS. 1 to 4, in a molding mold 1, a push rod 2 that presses and molds the powder put into the mold, and a molding mold. In order to adjust the depth of the positive electrode agent 4, the powder of the positive electrode material 4 is poured into the mold 1, which consists of a pedestal 3 that is movable up and down within the mold 1 (Fig. 1). The positive electrode material 4 is lightly pressed with the push rod 2 to level the ground, and then the powder of the separator material 5 is poured onto the positive electrode material 4 placed in the molding die i (this state is shown in FIG. 2), After that, the separator material 5 is lightly pressed with the push rod 2 to level the ground, and then the powder of the negative electrode material 6 is poured onto the separator material 5 placed in the mold l. This state is shown in Fig. 3. Then, the positive electrode material 4, separator material 5, and negative electrode material 6 placed in the molding die 1 are pressurized by the push rod 2, and are integrally molded, the state of which is shown in FIG. 4).
Layered tablets can be formed. Incidentally, the order in which the three types of powders described above are introduced into the molding die 1 for the positive electrode material 4 and the negative electrode material 6 may be reversed to the above-mentioned order.

Using this layered tablet (three-layer tablet-shaped battery element) taken out from the molding die 1, a battery is assembled as follows. As shown in FIG. 5, the molded body is placed in a battery container 9 in which a current collecting net 7 is welded and a gasket 8 is placed. After that, an electrolytic solution 10 is supplied and impregnated.

Next, the ion blocking electrode 12 having a convex curved shape is placed on the front 32 layered tablet in the container. FIG. 6 shows the state. The layered tablet is then placed on top of the ion blocking battery 12. At this time, insert the second and subsequent 11-shaped tablets so that the surface of the layered tablet that was introduced first is in contact with the ion blocking electrode 12, and the surface of the layer that is different from the surface that is in contact with the ion blocking electrode 12 is in contact with the ion blocking electrode 12. . The electrolytic solution is supplied in the same manner as described above. Finally, as shown in FIG. 7, the lid 11 to which the current collecting net 7 is welded is attached to the battery container 9 while pressing the contents of the battery container, and the battery container 9 and the lid 11 are caulked and sealed. do.

Next, a stacked battery of the present invention manufactured using a solid electrolyte will be explained.

This layered tablet consists of a positive electrode agent consisting of a positive electrode active material, a conductive agent, a binder, and a solid electrolyte, a separator agent consisting of a solid electrolyte and, if necessary, a binder, and a negative electrode active material, a conductive agent, and a binder. and a negative electrode agent consisting of a solid electrolyte, and a stacked battery can be constructed without adding an electrolyte in a subsequent step. The solid electrolyte is, for example, S b20. −/nHto (2≦n−≦5
), 5nOz·3HtO, or other acid hydrate hydrogen ion conductive solid electrolytes can be used. The amount of the positive electrode agent is usually 40 to 84% by weight of the positive electrode active material and 3 to 2% by weight of the conductive agent.
0% by weight, 3-20% by weight of binder and 10-20% of solid electrolyte
60% by weight, separator agent 50-100% by weight solid electrolyte and optionally less than 50% binder, negative electrode agent or negative electrode active material 40-84% by weight, conductive agent 3-20% by weight,
Binder 3-20% by weight and solid electrolyte 10-60% by weight
It can be done. The positive electrode active material, conductive agent, binder, and negative electrode active material may be the same as those used in the stacked battery using the electrolytic solution described above. By using this layered tablet, a layered battery can be produced in the same manner as the layered battery described above except for the electrolytic solution impregnation step.

(e) A layered tablet is placed in the working battery container, and an ion blocking electrode in the form of a convex curved plate with spring properties is placed on top of the layered tablet.
By repeating the process of placing the layered tablet again and enclosing the layered product while pressing it, the ion blocking electrode is spring-deformed from a convex curved plate shape to a flat plate shape, thereby forming a layered battery. Then, surface pressure of spring stress is applied to the layered tablet to connect the layered tablet in close electrical contact, thereby fixing the layered tablet.

(F) EXAMPLES AND COMPARATIVE EXAMPLES The present invention will now be explained in more detail with reference to Examples and Comparative Examples.

Example I First, 200 m of positive electrode powder was prepared by mixing 20 parts by weight of γ-manganese dioxide, 2 parts by weight of acetylene black as a conductive agent, and 1 part by weight of polytetrafluoroethylene powder and sodium carboxymethylcellulose as binders.
9 into a mold with an inner diameter of 13 mx, and press lightly with a push rod from above.

Next, separator agent powder 20019, which is a mixture of 20 parts by weight of α-alumina powder as an electrolytic solution support and 1 part by weight of carboxymethyl cellulose as a binder, was added to the positive electrode layer placed in the mold. 1. Press down lightly with the push rod from E.

Next, gaseous hydrogen was placed in a pressure container at 25°C for 1 hour.
Hydrogen storage alloy TiN1 stored overnight under atmospheric conditions
Powder of negative electrode material, which is a mixture of 180 m9 of acetylene black as a conductive agent and 10 R9 of carboxymethyl cellulose as a binder, is immersed on top of the separator agent placed in the molding die, and a push rod is applied from above to 200 K9w/cm. '
The molded body is then removed from the mold. This operation is repeated 30 times to obtain 30 powder compacts (layered tablets) having a three-layer structure, which are the battery contents.

Next, place this layered tablet so that the bottom side becomes the positive electrode.
Place the battery in a battery container to which an integrated gasket with an inner diameter of 15.5xm has been attached in advance, add 100μQ of a 30% by weight aqueous potassium hydroxide solution, and add a 50μ thick battery on top.
A δ-shaped curved plate-like nickel plate (ion blocking electrode) as shown in FIG.
Similarly, 30% by weight potassium hydroxide aqueous solution was added to
Add 00μQ. Then, the same operation is performed once again, and when the layered tablet, nickel plate, layered tablet, nickel plate, and layered tablet are stacked in this order in the battery container, the lid is closed and caulked. Ten test batteries A are produced in this way.

Immediately before the impact test of 10 test batteries A, the impact test was performed using an impact tester (model 5M-105; Hokusui Brown (Aji)) under the conditions of a maximum acceleration of 14,700 m/s' and a pulse width of 0.5 mm. 1 each in y and z directions
Test battery A was tested 0 times, and after being left for 10 days, the voltage and internal resistance of the sine wave IKHz were measured. As shown in Table 1, there was no increase in voltage or internal resistance even after the impact test. It was confirmed that it has excellent impact resistance. (Left below) Table 1 Comparative Example In Example 1, the 8th
Stacked battery B was prepared in the same manner as in Example 1 except that instead of using a nickel plate with a convex curved surface as shown in the figure, a flat nickel plate with a diameter of 15.2 mm and a thickness of 50 μm was used.
Make individual pieces.

This stacked battery BIO test direct voltage and internal resistance of sine wave IKHz, as well as impact tester (model
5M-105; Maximum acceleration 14700111/s', pulse width 0, 5m using Hokusui Brown Co., Ltd.
After performing the impact test 10 times each in the X, Y, and Z directions under the conditions of s, the voltage and internal resistance of a sine wave IKHz were measured after being left for 10 days. As a result, as shown in Table 2,
Shino 3 failed due to increased internal resistance during the impact test.
This battery B had poor impact resistance.

Table 2 Example 2 As a positive electrode material, 20 parts by weight of γ-manganese dioxide, 1 part by weight of acetylene blank as a conductive agent, and 1 part by weight of polytetrafluoroethylene powder and sodium carboxymethylcellulose as binders. In addition, 5byOs 4H70, which is a hydrogen ion conductive solid electrolyte,
Mix 5 layers and 1 part of this 200j+9 to an inner diameter of 13+u
Pour into the mold and press lightly with a push rod from above.

As a separator agent, 10 parts by weight of 5btOs 4H20, which is a hydrogen ion conductive solid electrolyte, and 1 part by weight of carboquinomethyl cellulose, which is a binder, are combined, and this 200z9 is placed in the mold for forming the mold. Pour it onto the positive electrode material and press it lightly with a push rod from above.

As a negative electrode agent, gaseous hydrogen is placed in a pressure-resistant container.
Acetylene black lOIIIg as a conductive agent, sodium carboxymethylcellulose as a binder were added to TTiN1150t, a hydrogen storage alloy that had been stored overnight at 25°C and 1 atm, and 5btOs, a hydrogen ion conductive solid electrolyte.・Powder a mixture of 4H, O and 40z9 onto the separator material placed in the mold, and press a push rod from above to 200K9v/c.
m'' pressure and take out the molded body from the mold. This series of operations is repeated 30 times to obtain 30 powder molded bodies (layered tablets) having a three-layer structure, which are battery contents.

Next, place this layered tablet so that the bottom side becomes the positive electrode.
It is placed in a battery container to which a polypropylene integral gasket with an inner diameter of 15.5zx is attached in advance, and a nickel plate (ion blocking electrode) having a shape as shown in Fig. 9 with a thickness of 50 μm and a diameter of 15.2 + y* is placed on top of it. Then, place the layered tablet so that the bottom side or the positive electrode is facing, place the above-mentioned ion blocking electrode on top of it, place the layered tablet again so that the bottom side is the positive electrode, and place it in the battery container. , layered tablet,
Once the nickel plate, layered tablet, nickel plate, and layered tablet are stacked in this order, the lid is placed and caulked to seal. In this way, test battery C 109 is produced.

Immediately before the test of 010 test batteries, and an impact tester (model 5M-105; Hokusui Brown Co., Ltd.)
) with a maximum acceleration of 1.47 QOm/s' and a pulse width of 0 and 5 ms, the impact test was performed 10 times each in the X, Y, and Z directions, and after being left for 10 days, each voltage and sine wave The internal resistance at IKHz was measured. As shown in Table 3, there was no increase in voltage or internal resistance after the impact test, confirming that this test battery C had excellent impact resistance.

(The following is a blank space) Table 3 to FIG. 10 are explanatory diagrams of the ion blocking electrodes of the stacked batteries or embodiments produced in the examples of the present invention.

l...Molding mold, 2...Push rod, 3
...... pedestal, 4... cathode material,
5... Separator agent, 6... Anode agent, 7A, 7B... Current collection net, 8...
Gasket, 9...Battery container, IO...
... Electrolyte, (I... Lid, [2...
...Ion blocking electrode.

(G) Effects of the Invention According to the present invention, it is possible to provide a laminated battery that has good electrical contact with the layered tablet (battery element), has a high manufacturing yield, and has improved drop strength (impact resistance). I can do it.

[Brief explanation of the drawing]

Claims (1)

[Scope of Claims] 1. A plurality of layered tablets formed by laminating and pressurizing a positive electrode material, a separator material, and a negative electrode material in order are laminated via an ion blocking electrode, and are impregnated with an electrolytic solution as necessary. . A stacked battery sealed in a battery container, wherein the ion blocking electrode is made of a conductor in the shape of a convex curved plate with spring properties. 2. The layered tablet contains a positive electrode agent consisting of a positive electrode active material, a conductive agent, a binder, and a solid electrolyte, a separator agent consisting of a solid electrolyte and, if necessary, a binder, and a negative electrode active material, a conductive agent, and a binder. 2. The stacked battery according to claim 1, comprising a negative electrode agent comprising a negative electrode agent and a solid electrolyte.