JPS62198052A - Laminated type zinc chloride cell - Google Patents

Abstract

PURPOSE:To construct a cell of high performance and good storableness by using a main electrolyte composed of chemical manganese dioxide and a combined electrode of carbon and zinc consisting of three dimensional combined electrode with electroconductive carbon layer. CONSTITUTION:A cell is constructed with a main electrolyte of zinc chloride, a positive electrode active materials of chemical manganese dioxide having gammatype crystal structure, and a combined electrode of carbon and zinc consisting of a can-shaped or similar three dimensional combined electrode 3 on the whole or a part of outer surface of which an electro-conductive carbon film 2 is provided. The purity of the chemical manganese dioxide is necessary to be higher than 88wt% and desirable to be higher than 90wt%. Thereby the physical property of the zinc chloride composite can be improved without lowering of the discharge capacity in comparison with the cell made of electrolytic manganese dioxide, and especially by using together the can-shaped or similar three dimentional combined electrode the deformation of the zinc chloride composite at the stack assembly can be prevented more effectively to obtain the stack of high dimensional accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a manganese dioxide positive electrode and a carbon-zinc bonded electrode for a stacked zinc chloride battery.

[Prior Art] Stacked batteries were originally developed as small, high-performance high-voltage batteries, in contrast to high-voltage assembled batteries in which multiple cylindrical batteries were wired together. Batteries of various sizes ranging from ■ to several tens of inches O■ have been commercialized.A variety of structures have been proposed for stacked batteries in the past, but at present, volumetric efficiency, suitability for mass production, and cost The so-called "Mini-max type" molded structure, which is excellent in terms of The carbon-zinc bonded electrode (2i
nc-carbon Duplex Electrod
A plate-shaped positive electrode mixture is placed on the zinc negative electrode surface via a thin paste layer and a cup-shaped separator, and the entire periphery is covered with a heat-shrinkable annular plastic film. (hereinafter referred to as a cell grommet) to form a unit cell (hereinafter referred to as a cell), and after stacking multiple cells, both ends are clamped and fixed via an internal terminal board, and then The entire cell is covered with an insulating material such as wax mixed with the cell stack (hereinafter referred to as stack).
qru.

After the stack is wrapped again in a heat-shrinkable cylindrical plastic film (hereinafter referred to as stack grommet), it is placed in an outer container with external terminals, and the internal and external terminals are electrically connected to form a battery. (Batteries
) will be completed.

In this case, the positive electrode is made of high-grade, highly active electrolytic manganese dioxide (Electrolytic Hanganese D).
ioxide) and acetylene black, ammonium chloride as the main electrolyte, and small amounts of Pb, Cd, and anode as the negative electrode.
The zinc plate was made of high-purity electrolytic zinc added with AI, etc., and was made into a starch.

The biggest feature of this battery is that it has a layered structure, does not require an empty space (air 5 space) within the cell, and does not require interconnections between cells, so it has a high volumetric efficiency. The disadvantage was that the internal impedance was relatively large, making it unsuitable for rapid discharge.

In recent years, with the diversification of devices that use batteries as a power source, there has been a demand for improved rapid discharge capacity, and improvements have been made for this purpose. One effective method is to use zinc chloride as the main electrolyte instead of the conventional ammonium chloride. As is well known, zinc chloride batteries that use zinc chloride as the main electrolyte have a different electromotive reaction during discharge from so-called Leclanche batteries, whose main electrolyte is ammonium chloride, and if manufacturing conditions are appropriate, rapid discharge characteristics can be achieved. and leakage resistance is significantly improved. The electromotive reaction equations of the Lecrancier battery (1) and the zinc chloride battery (2) are shown below.

2) 1no 2 +2 N84 Cl +1n=2
)1no (0 former 10 Zn(NH3) 2 Cl2-(1
)8MnO2+ZnCl2+8H20+4Zn-8Mn
O (Oll) + ZnCl24 Zn (O former 2-(2)) For this reason, a considerable portion of cylindrical dry batteries are already made with zinc chloride.On the other hand, it is difficult to use zinc chloride in laminated batteries due to production technology. Due to these drawbacks, only a few attempts have been made to commercialize it.

We will discuss some of the most typical problems when converting laminated batteries into zinc chloride. The first is the peculiar behavior of zinc chloride electrolyte towards acetylene black. In other words, when press-molding a wet positive electrode mixture (wet fix) obtained by adding an electrolyte to a mixture (dry mix) mainly consisting of manganese dioxide and acetylene black, it contains an electrolyte containing ammonium chloride as the main electrolyte. Positive electrode mixture (
The positive electrode mixture (hereinafter referred to as zinc chloride mixture), which contains an electrolyte with zinc chloride as the main electrolyte, exhibits powder-like behavior with appropriate compressive cohesiveness and impact resilience. In the case of (abbreviated as abbreviated)), it exhibits a kind of quasi-fluid behavior, and the pressure loss during molding is large, making it difficult to mold it into a predetermined shape and density. Further, the obtained plate-shaped molded mixture (Mix Cake) has a disadvantage that it has low strength and is easily deformed even by a relatively small external force. Furthermore, if the molded mixture undergoes plastic deformation due to an external force, depending on the degree of plastic deformation, the impedance of the positive electrode mixture itself may increase, resulting in a decrease in performance and deterioration of storage characteristics.

The second problem is due to the difference in discharge mechanism. In Leclanche batteries, the source of protons, which are the main polarizing ions during discharge, is NH4Cl. Therefore, in order to obtain sufficient discharge capacity, the active material ammonium chloride must be used in large excess with respect to the saturated dissolved amount of the electrolyte. Generally, it is used as an added heterogeneous system, which results in favorable results in terms of the physical properties of the positive electrode mixture.

On the other hand, in zinc chloride batteries, the proton donor is H2C
Therefore, in order to obtain a sufficient discharge capacity, it is necessary to add a larger amount of water as an electrolyte than in the Lucranci mixture. As is well known, the amount of electrolyte retained by the positive electrode mixture mainly depends on the amount of liquid absorbed by acetylene black, and the amount of liquid absorbed by acetylene black varies slightly depending on the type, but is generally 3.6 to 3.8 d/(l). The amount of electrolyte retained in the zinc chloride mixture to obtain a sufficient discharge utilization rate is close to or above the limit value of the liquid absorption amount mentioned above, and therefore the above-mentioned disadvantages of the zinc chloride mixture are This further promotes the quasi-fluid behavior when pressurized.In addition, the presence of a large amount of electrolyte in the positive electrode mixture is another important function of acetylene black, which is the ability to make effective electrons within the positive electrode. In other words, poor contact between acetylene black and manganese dioxide particles (Loose Con
tact) to increase the internal impedance of the cell.

The third problem is caused by the (lini-Hax) structure of the stacked battery. In other words, the structure is such that a plurality of cells are stacked one on top of the other and the entire cell is clamped and fixed in the stacking direction to maintain the necessary contact between the structural elements inside the cells and between the cells, whereas the cell container is flexible. Since the cell grommet is made of a cell grommet with no structural strength, external pressure is mainly received by the positive electrode mixture. In the case of using the Lucranci mixture, the positive electrode mixture has the minimum strength necessary to maintain the above-mentioned contact pressure. On the other hand, with zinc chloride mixture, when the stack is compressed, the positive electrode mixture inside the cell is easily deformed and crushed in the direction perpendicular to the external pressure. does not have enough strength to effectively prevent deformation of the positive electrode mixture, the cell grommet also deforms at the same time, increasing pressure loss, making it difficult to maintain the necessary contact pressure between the elements within the cell and between the cells. 1. In other words, rotation is to maintain a stable contact state necessary for the battery to perform its function without causing large deformation to the cell or stack.

For the above reasons, conventional laminated zinc chloride batteries tend to exhibit variations in performance and suffer from significant deterioration of characteristics during long-term storage, but no effective countermeasures have yet been proposed to address these basic problems. .

The present invention solves the nuclear problem by using chemical manganese dioxide having a γ-type crystal structure as the positive electrode active material, and using a can-shaped or can-like three-dimensional bonded electrode as the carbon-zinc bonded electrode. The purpose of this invention is to provide a practical laminated zinc chloride battery with high performance and good storability.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a laminated zinc chloride battery in which manganese dioxide is used as a positive electrode active material and zinc is used as a negative electrode active material, in which zinc chloride, zinc chloride, The positive electrode active material is γ
Laminated zinc chloride using chemical manganese dioxide having a type crystal structure and a can-shaped or can-like three-dimensional bonding electrode having a conductive carbon film on the whole or part of the outer surface as a carbon-zinc bonding electrode. It's a battery.

[Function] The present inventor proposed (1) electrolyte retention of the positive electrode mixture as a means for alleviating or preventing the quasi-fluid behavior of the zinc chloride mixture during pressurization and the shape change of the molded mixture caused by it. (2) Adding a substance that increases the capacity and deformation resistance of the molded body; (2) having not only acetylene black but also manganese dioxide take part in retaining the electrolyte in the positive electrode mixture;
3) Improvements were attempted mainly by limiting the deformation of the positive electrode mixture by increasing the structural strength of the cell.

First, we selected modified polysaccharides, cellulose derivatives, etc. that have oxidation resistance against electrolytic manganese dioxide, and added appropriate amounts of them to the positive electrode mixture in an attempt to improve the defects in the zinc chloride mixture. Patent No. 696 previously proposed by the present inventor
According to No. 556, by adding Gum Kalaya in a specified amount of 1q to the Leclancier battery, which is a stacked battery, the molding workability is good even when a large amount of electrolyte is added, and the rapid discharge characteristics and leakage resistance of the battery are improved. Liquid properties can be significantly improved. An attempt was made to apply this method to a stacked zinc chloride battery, but without success. In other words, when a small amount of karaya gum is added, although a slight improvement in molding workability is observed, the expected effect is not obtained, and when a considerable amount of karaya gum is added, the cell impedance increases sharply and No such effect was observed in the case. This increase in impedance is mainly due to an increase in the contact resistance between particles within the positive electrode mixture and the contact resistance between the conductive carbon film on the surface of the bonded electrode and the positive electrode mixture. When various modified polysaccharides, cellulin derivatives, etc. other than karaya gum were used, the increase in cell impedance was generally even greater, or the deformation resistance of the positive electrode mixture could not be increased, and no effect of addition could be obtained. .

In any case, adding a considerable amount of the third substance to the positive electrode mixture is accompanied by a relative decrease in the weight of the active material, so it is not very preferable unless significant other benefits can be obtained.

Next, we attempted to have manganese dioxide itself, which is the positive electrode active material, share a portion of the amount of electrolyte required by the positive electrode mixture.

Generally, manganese dioxide prepared by chemical means has a larger surface area and average pore diameter than electrolytic manganese dioxide, and has about twice the amount of liquid absorbed.

Therefore, it should be useful for improving defects in zinc chloride mixtures.

However, currently mass-produced manganese dioxide is all synthesized manganese dioxide by the method shown in formula (3) below, and this is a substitute for electrolytic manganese dioxide because it has a ρ-γ type crystal structure and has poor rapid discharge characteristics. It is difficult to replace it as .

2Hn2co3+02 →2Hn02 +2CO2"i
l) On the other hand, chemical manganese dioxide, which is produced by subjecting a lower oxide of manganese to a disproportionation reaction, has a γ-type crystal structure similar to electrolytic manganese dioxide, as shown in the following formula (4) or (5). It has good rapid discharge characteristics.

Mn203 + H2SO4- Mn02 + HnS04 + Town 0 ----------・(
4) Mn304 +2 H2304= )1n02 +2)1nS04+2 H20””(5)
The lower oxide, which is the raw material for the above-mentioned disproportionation reaction, can be obtained by reduction sooting of a higher oxide or heating oxidation of a divalent manganese salt. Therefore, the purity (Mn02) of chemical manganese dioxide produced by 1q in the disproportionation reaction depends on the purity of the lower oxide or divalent manganese salt that is the raw material.

When chemical manganese dioxide obtained by a disproportionation reaction is used in a stacked zinc chloride battery, rapid discharge characteristics are good even when the purity is relatively low, for example, around 80%. Load discharge capacity is poor. As a result of the investigation, chemical manganese dioxide prepared by disproportionation reaction must have a purity of about 88% or more, preferably 90%, in order to obtain a light capacitance that is roughly between that of the currently used electrolytic manganese dioxide.
It was acknowledged that more than 50% of weight was required. If the raw material for the lower oxide used in the disproportionation reaction is a divalent mankane salt, it is easier to use 1q of high purity, but if the raw material is a higher oxide such as a natural ore, high-grade ore is enough. It is necessary to smelt it and use it.

Electrolytic manganese dioxide can be produced by using chemical manganese dioxide, which has a γ-type crystal structure with a purity of 88% by weight or more and is obtained by disproportionation reaction of high-grade lower oxides such as those shown in the above, in a zinc chloride mixture. It was possible to improve the deformation resistance of the molding mixture to some extent without deteriorating the load/capacity characteristics of the battery compared to when using this method. In this case, when the raw material for the lower oxide used in the disproportionation reaction is a synthetic material, the chemical manganese dioxide obtained is synthetic manganese dioxide (C
chemical 5ynthetic)fangan
ese Dioxide), activated manganese dioxide (Chemical
Activated Hanganes Dioxide
It is called e.

In addition, chemical manganese dioxide with a γ-type crystal structure has a particle size of 1
It has been experimentally found that when a large amount of so-called Zabumicron particles of .mu.m or less are contained, the deformation of the molding mixture due to external pressure is further reduced.

However, since the miniaturization of manganese dioxide is accompanied by a decrease in bulk density and a decrease in the charging capacity of the positive electrode mixture in the cell, i.e., a decrease in discharge capacity, the practical appearance is reduced to secondary particles with a fine particle size. It is necessary to cover it after use. The effect is recognized when the amount of the submicron particles contained in the secondary particles exceeds about 30% by weight, and the effect is even more obvious when the amount of the submicron particles contained in the secondary particles is preferably 50% by weight or more.

In addition, regarding ultrafine pulverization, the economical pulverization limit when finely dividing solids using generally known pulverization methods is approximately 3 μm, and obtaining fine particles of 1 μm or less at an economical yield is difficult. has been done.

However, it is actually possible to scale the fine powder of chemical manganese dioxide or its raw material containing a large amount of submicron particles by long-term batch pulverization using a vibratory ball mill, etc., or by crushing with a high-pressure press. It is.

However, even when high-purity chemical manganese dioxide having a γ-type crystal structure as described above is used, it cannot be said that the plastic deformation of the zinc chloride mixture can be suppressed to a sufficiently effective level for practical use. The inventor recognized the need to make changes to the conventional cell structure, which did not have the necessary structural strength to prevent plastic deformation of the zinc chloride mixture when the cell or stack was compacted, and made improvements thereto. . In other words, as a result of considering a method to provide the cell with the necessary structural strength without significantly impairing the high volumetric efficiency and suitability for mass production based on the simple structure of current stacked batteries, we found that the bonding electrode, which had been conventionally used in a flat form, It has been found that it is extremely effective to create a three-dimensional structure in which the peripheral edge rises to form a side wall. When a conventional flat carbon/zinc bonded electrode is used, the side surface of the positive electrode mixture is covered with a flexible cell grommet thin layer through the rising part of the cup-shaped separator encasing the positive electrode mixture. However, when the three-dimensional bonding electrode of the present invention is used, the entire cell is supported by the side wall of the bonding electrode. This provides structural strength to the material and effectively prevents deformation of the mixture.

Furthermore, as a side effect of using the three-dimensional bonded electrode, the viscosity of the cell dimensions is also improved. In other words, when the cell grommet heat-shrinks in the cell manufacturing process, in the conventional structure, the shrunken cell grommet comes into contact with the rising part of the cup-shaped separator, whereas in the structure of the present invention, the shrunk cell grommet has a smaller size and shape. This is because it is accurate and adheres closely to the side wall portion of the three-dimensional bonding electrode with a smooth surface.

The can shape of the three-dimensional coupling electrode used in the present invention means that the entire end of the coupling electrode has an arbitrary shape such as circular, square, or rectangular, corresponding to the cell shape, and forms a continuous side wall that stands up. It is shaped like a round can or square box, and a can-like shape is one in which a large part of the edge of the coupling electrode rises to form a side wall, giving it a can-like appearance. This refers to a structure in which a part of the side wall has a missing part and the entire side wall is not formed continuously.

Figures 1a and b show examples of how the three-dimensional coupling electrode of the present invention is constructed.
, c, and d. In FIG. 1, 1 is a zinc electrode, 2 is a conductive carbon film, and 3 is a side wall portion of a combined electrode in which 1 and 2 are integrally formed.

Figure 1 a shows a can-shaped three-dimensional coupling electrode for a circular cell, Figure 1 shows a can-shaped three-dimensional coupling electrode for a rectangular cell, and Figure 1 d shows a can-like three-dimensional coupling electrode for a rectangular cell. Each electrode is shown.

Further, FIGS. 1A and 1C show an example in which the side wall portions of the coupling electrode are formed substantially vertically, and FIG. 1 shows an example in which the side wall portions are inclined outward from top to bottom.

In addition, Fig. 1 a, b, and d are examples in which a conductive carbon film layer is integrally formed on the entire outer surface of the three-dimensional coupling electrode, and Fig. 1 C
This is an example in which a conductive carbon film is formed only on the external bottom surface of the three-dimensional coupling electrode, that is, the surface facing the adjacent cell.

As described above, the height of the side wall portion of the three-dimensional coupling electrode is designed to be slightly lower than the upper surface of the positive electrode molding mixture inserted into the coupling electrode via the cup-shaped separator. This is to ensure contact between the positive electrode mixture and the conductive carbon crotch of the adjacent cell. In addition, it is preferable that the rising angle of the side wall portion of the coupling electrode be approximately perpendicular to the bottom surface of the coupling electrode from the viewpoint of volumetric efficiency, but in consideration of production, it may be inclined outward slightly, for example, by about 0.2 to 10 degrees. You can leave it there.

The three-dimensional bonding electrode can be obtained by mechanical secondary processing of a flat carbon/metallic bond electrode original plate, or by drawing a zinc original plate for batteries.

Further, the conductive carbon film layer can be formed by any method such as coating with a solvent-based or non-solvent type conductive carbon paint, or thermocompression bonding of a conductive carbon film. In the case of a structure in which a conductive carbon film layer is formed only on a part of the outer surface of the three-dimensional bonded electrode,
It is necessary to form it at least on the bottom outer surface of the three-dimensional zinc negative electrode, that is, on the surface facing adjacent cells.

Among the above-mentioned methods for forming three-dimensional bonded electrodes, there are technical aspects.

In the case of can-shaped bonded electrodes, a particularly economically suitable method is to apply graphite and/or acetylene in a polyisobutylene vehicle to the outer bottom surface of a three-dimensional zinc negative electrode obtained by drawing a zinc blank for batteries. There is a method of forming a pressure-sensitive conductive film using carbon black such as black as a pigment.

In addition, in the case of a three-dimensional bonded electrode with a can-like shape, damage to the conductive carbon film layer is avoided because only the process of punching a flat carbon/zinc bonded electrode plate into a special shape and the process of bending the side wall are required. It is also rational, with less material loss. Regarding a three-dimensional coupling electrode having a can-like shape and a method for manufacturing the same, there are Japanese Patent No. 594209 and Utility Model No. 925288 proposed by the present inventor. When such a three-dimensional bonding electrode with a shape similar to a can is used, there is a part of the side wall with a notch, but if the notch area is small, the deformation of the zinc chloride mixture will be smaller compared to a can-shaped electrode. It has been experimentally confirmed that the blocking effect is almost as good.

As a branch of the present invention, the physical properties of the zinc chloride mixture are improved by using chemical manganese dioxide having a γ-type crystal structure as the positive electrode active material without reducing the discharge capacity compared to when electrolytic manganese dioxide is used. can,
In particular, by using can-shaped or can-like three-dimensional bonding electrodes, deformation of the zinc chloride mixture during stack assembly can be more effectively prevented, and stacks with high dimensional accuracy can be made by 1q.
can be done.

As a result of these, as shown in the examples described later, the heavy load characteristics and #4 leakage properties are significantly superior to the conventional stacked Lecrancier battery using electrolytic manganese dioxide and a flat bonded electrode. Compared to a stacked zinc chloride battery using a flat plate-type bonded electrode, this battery not only has superior long-term storage stability, but also has improvements such as less variation in characteristics and the ability to use negative electrode zinc without aging. It is something that can be done.

[Example] Examples of the present invention will be described below.

Table 1 shows the molding workability when molding laminated mixtures with wet positive electrode mixtures using various types of manganese dioxide and the deformation state when constant pressure is applied to the positive electrode mixture molded body (fix cake) using electrolytic manganese dioxide. It is expressed as a relative sensory value index when the conventional mixture consisting of and Lecrancier electrolyte is set as a standard (1,0).

Table 1 In Table 1, Conventional Example A is a submicron particle with a particle size of 1 μm or less.
Conventional example B is a typical positive electrode mixture for conventional laminated dry batteries, consisting of electrolytic manganese dioxide with a secondary particle content of 18% by weight and purity of 91.5%, and Lecrancier electrolyte whose main electrolyte is ammonium chloride. A positive electrode mixture for a conventional laminated zinc chloride battery containing a zinc chloride electrolyte with zinc chloride as the main electrolyte and the same electrolytic manganese dioxide as in Conventional Example A, Invention C has an ultrafine powder content of 66% by weight and purity. A positive electrode mixture containing 89.2% γ-type chemically synthesized manganese dioxide and zinc chloride electrolyte, the present invention contains γ-type chemically synthesized manganese dioxide with an ultrafine powder content of 22 times ε% and a purity of 91.7%. Invention E is a positive electrode mixture consisting of a zinc chloride electrolyte and γ-type chemically synthesized manganese dioxide with an ultrafine powder content of 63% by weight and a purity of 91.7% and a zinc chloride electrolyte without adding mercuric chloride. The positive electrode mixture, Invention F, is γ with an ultrafine powder content of 63% by weight and a purity of 91.7%.
Molded semi-synthetic manganese dioxide 70 parts by weight and ultrafine powder content 5
Invention G, a positive electrode mixture using a manganese dioxide mixture consisting of 30 parts by weight of electrolytic manganese dioxide with a purity of 91.0% and a zinc chloride electrolyte, has an ultrafine powder content of 63% by weight and Ml! 85% T-type semi-synthetic manganese dioxide 85
Each of the positive electrode mixtures includes a mixed manganese dioxide consisting of electrolytic manganese dioxide with a purity of 91.5% and an ultrafine powder content of 15% by weight, and a zinc chloride electrolyte.

As can be seen from Conventional Examples A and B in Table 1, when a zinc chloride electrolyte is used in a mixture of electrolytic manganese dioxide and acetylene black, a constant pressure is applied to the molding mixture compared to when Leclancier electrolysis) 1k is used. It can be seen that the degree of deformation caused by the addition becomes large and the molding workability is also significantly reduced. On the other hand, by using chemical manganese dioxide with a γ-type crystal structure, the degree of deformation and molding workability are considerably improved even in the case of zinc chloride electrolyte, and the content of ultrafine particles is high. It can be seen that the use of T-type chemical manganese dioxide consisting of dense secondary particles is even more effective.

Furthermore, even if 30% by weight of electrolytic manganese dioxide with a high ultrafine powder content or 15% by weight of electrolytic manganese dioxide with a low ultrafine powder content is substituted for γ-type chemical manganese dioxide, the key shape and workability will be noticeable. It can be seen that there is no decrease. However, if the electrolytic manganese dioxide substitution rate exceeds about 40% by weight, the degree of deformation and molding workability rapidly become close to those of Conventional Example B, which is not preferable. Therefore, in carrying out the present invention, in practice 30
It is possible to mix electrolytic manganese dioxide in an amount of about % by weight or less.

The present invention will be explained below with reference to the drawings.

A cross-sectional view of the MA structure of a conventional stacked dry battery cell is shown in Figure 2a.
Further, a cross-sectional view of the structure of a cell for a laminated zinc chloride battery according to the present invention is shown in FIG. In Fig. 2a, 21 is a flat zinc electrode, 22 is a conductive carbon film, 23 is a flat carbon-zinc bonded electrode in which 21 and 22 are integrally formed, and 24 is a zinc negative electrode surface or a negative electrode facing the separator. A thin paste layer formed on the surface, 25 a cup-shaped separator, 26 electrolytic manganese dioxide 1. A positive electrode mixture consisting of acetin black, an electrolyte containing ammonium chloride or zinc chloride as the main electrolyte, and other additive components such as zinc oxide, 2
7 is a cell grommet, and 28 is an adhesive. Also the second
An example of a cross-sectional view of a cell structure of a stacked zinc chloride battery according to the present invention is shown in the figure. 1 is a three-dimensional zinc electrode, 2 is a conductive carbon film formed only on the outer bottom surface of 1, that is, the surface facing adjacent cells, 3 is a three-dimensional bonding electrode consisting of 1 and 2, and 4 is a vertical structure at the periphery of the three-dimensional bonding electrode. In the raised side wall part, 5 is a paste layer, 6 is a cup-shaped separator, 7 is a chemical manganese dioxide having a T-type crystal structure, acetylene black, an electrolytic solution containing zinc chloride as the main electrolyte, and other additions such as trace amounts of zinc oxide. 8 is a cell grommet, and 9 is an adhesive. When the conductive carbon film 2 is made of a relatively thick heat-pressure sacrificial film, the adhesive 9 can be omitted. Figure 3 shows a stacked zinc chloride battery 6F, which is an embodiment of the present invention.
A partially cutaway view of 22 is shown. In FIG. 3, 1 is a three-dimensional zinc negative electrode, 2 is a conductive carbon film, and 1 and 2 constitute a three-dimensional bonding electrode 3 having a shape similar to that of a can. 4 is a side wall of a coupling electrode, 6 is a cup-shaped separator, 7 is a molded mixture using chemical manganese dioxide with a γ-type crystal structure and zinc chloride electrolyte, 8 is a cell grommet, 10 is a mixed wax coating layer, 11 1 is a stack grommet, 12 is an outer can, 13 is a positive terminal, and 14 is a negative terminal.

The results of comparing the characteristics of stacked zinc chloride batteries manufactured by the conventional method and the method of the present invention will be described below.

Table 2 shows two stacked batteries 6F22 manufactured under various conditions.
Comparative example of initial discharge characteristics after aging for 7 days at 0''C, Table 4 shows the characteristics when 6 ton 22 stacked zinc chloride batteries are stored for a long period in a constant temperature atmosphere at 20'C and 45°C. In Tables 2 to 4, conventional example A is a laminated Lecrancier battery using the same Lecrancier mixture as in Table 1 A and a conventional flat bonding electrode, and conventional example B is a laminated Lecrancier battery using the same Lecrancier mixture as in Table 1 A, and a conventional example B as in Table 1 B. Comparative Example C is a conventional laminated zinc chloride battery using the same zinc chloride mixture and flat bonded electrode.
A laminated zinc chloride battery using the same zinc chloride mixture and flat bonding electrode as in Table C, and a laminated zinc chloride battery using the same zinc chloride mixture and can-shaped three-dimensional bonding electrode as in Table 1. A zinc battery, Invention E, is a non-transforming laminated zinc chloride battery using the same mercuric chloride-free zinc chloride mixture as in Table 1 E and a three-dimensional bonded electrode shaped like a can, Invention F is A laminated zinc chloride battery using the same zinc chloride mixture and can-shaped three-dimensional bonding electrode as in Table 1 F, and Invention G uses the same zinc chloride mixture and can-shaped three-dimensional bonding electrode as in Table 1 G. The laminated zinc chloride batteries used are shown.

As can be seen from the initial electrical characteristics in Table 2, a battery that combines a zinc chloride mixture with a plate-shaped bonded electrode has a high internal impedance and a small short-circuit current. Improved by using. Furthermore, as can be seen from conventional examples A and B in Table 3, in terms of initial discharge characteristics, by using a zinc chloride electrolyte, even when electrolytic manganese dioxide is used, compared to when using a Lecrancier electrolyte, the rapid discharge characteristics are particularly improved. It can be seen that the rapid discharge characteristics are significantly improved and that the rapid discharge characteristics are further improved by using the zinc chloride mixture together with the three-dimensional electrode.

Table 2 Table 3 Table 4 Despite the use of negative electrodes, the characteristics retention rate during long-term storage was good, and even when the battery was disassembled after storage at 45°C for 3 months and at 20"G for 12 months, the negative electrode No problematic uneven consumption or self-discharge products were observed on the zinc surface, indicating that the high M!C chemical manganese dioxide used contained almost no harmful metal oxides in alkali-soluble form. This is due to the fact that the cell shape is good and the dimensional accuracy is high due to the use of the three-dimensional type bonding electrode, and the amount of air remaining in the cell is extremely limited compared to when using the conventional flat type bonding electrode. It is thought that this is the case.

The present invention, like a craftsman, has high productivity and economy in practical use, reduces the internal impedance of laminated dry batteries, and improves not only excellent rapid discharge characteristics but also low characteristic retention during long-term storage. It is possible to provide a laminated battery with large and excellent resistance to wet liquids.Also, even if the negative electrode zinc becomes non-oxidizing, the property retention rate during long-term storage is not reduced, and is of great industrial value.

[Brief explanation of drawings]

Figures 1a, b, and c are longitudinal cross-sectional views of a can-shaped three-dimensional bonding electrode used in a laminated film zinc chloride battery according to an embodiment of the present invention;
Figure 1 d is a perspective view of a three-dimensional bonding electrode with a can-like shape used in the same laminated zinc chloride battery, Figure 2 a is a longitudinal cross-sectional view of a unit cell of a conventional laminated battery, and Figure 2 is a book. A vertical cross-sectional view of a unit cell of a laminated film zinc chloride battery in one embodiment of the invention,
FIG. 3 is a partially cutaway vertical sectional view of a laminated film zinc chloride battery 6F22 in one embodiment of the present invention. 1... Three-dimensional zinc electrode 2... Conductive carbon film 3
...3D bonding electrode

Claims (6)

[Claims] (1) In a stacked battery that uses manganese dioxide as the positive electrode active material and zinc as the negative electrode active material, the main electrolyte is zinc chloride, the positive electrode active material is chemical manganese dioxide with a γ-type crystal structure, and the carbon-zinc bonded electrode 1. A stacked zinc chloride battery comprising a can-shaped or can-like three-dimensional bonded electrode having a conductive carbon film layer on the entire or part of its outer surface. (2) The laminated zinc battery according to claim 1, wherein the chemical manganese dioxide is synthetic manganese dioxide or activated manganese dioxide. (3) The MnO_2 content of the chemical manganese dioxide is 88
Claim 2, characterized in that it is at least % by weight.
The laminated zinc chloride battery described in . (4) The chemical manganese dioxide has a particle size of 1μ as a primary particle.
4. The laminated zinc chloride battery according to claim 1, wherein the battery is composed of fine secondary particles containing 30% by weight or more of ultrafine particles with a particle size of 1.0 m or less. (5) The stacked zinc chloride battery according to claim 1, wherein the conductive carbon film layer on the outer surface of the three-dimensional bonding electrode is formed only on the surface facing adjacent cells. (6) The laminated zinc chloride battery according to claims 1 and 5, characterized in that the negative electrode zinc is not oxidized.