JP2016012468A - Press type battery case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal air battery that can suppress distension of a laminate of a polar plate group serving as a core of a battery cell under power generation and generate power continually and stably in a battery such as a magnesium battery or the like.SOLUTION: In a magnesium battery, magnesium, a separator, active carbon and metal are successively laminated in this order to form a laminate, one or more laminates are densely arranged in a lamination direction, the laminates are mounted in an inner housing of a dual cylindrical housing, a reinforcing plate is disposed in the lamination direction at the outside of the inner housing and inside an outer housing, electrolyte is injected to the laminates to generate power, and the laminates are suppressed from distending in the progress of a power generating chemical reaction.

Description

The present invention relates to a structure that suppresses expansion of an electrode laminated structure by a battery casing.

Magnesium batteries have high energy density, high safety, and light weight. The material magnesium is extremely abundant and inexpensive.

Magnesium batteries generate magnesium hydroxide by generating electricity, which can be converted to magnesium again by raising the temperature after separation from the electrolyte and is expected as a circulating battery material.

A magnesium battery constitutes a battery cell by stacking four layers of magnesium or a magnesium alloy serving as a cathode active material and a metal such as a separator, activated carbon, and copper serving as an air electrode in the order described. This is called a laminate. A normal battery has the same structure as this laminate.

The separator can hold the electrolytic solution with a non-conductive material nonwoven fabric or the like. In addition, the separator and activated carbon perform an action of taking in oxygen from the air. When an electrolyte is injected into the separator, a chemical reaction as a battery occurs and power is generated.

The reaction of the magnesium battery can be expressed by the following chemical formula.

2Mg + O2 + 2H2O → 2Mg (OH) 2 ↓ ... Chemical reaction formula 1
Alternatively, the reaction in the absence of oxygen around the electrode can be expressed by the following chemical formula.

Mg + 2H2O → Mg (OH) 2 ↓ + H2 Chemical reaction formula 2
In practice, both reactions mix to generate electricity.

The magnesium battery has a reduced power generation performance, such as magnesium hydroxide generated by power generation, and the surface of the magnesium electrode swells, the contact with the anode becomes unstable, and the internal resistance increases. Swelling does not necessarily occur uniformly on the entire surface of the magnesium electrode plate, and the surface of the magnesium electrode plate may become irregular.

In order to suppress such a situation, it is necessary to avoid the power generation performance from being lowered by strongly pressing the surface of the laminate. For this purpose, a structure has been proposed in which a pair of opposing side walls of a case for storing battery cells is curved inward, and when the laminate is expanded and the case is deformed, the battery cell is pressed by reaction force. ing. (Patent Document 1)

With such a structure, there is a problem that a pressing force works from the central portion of the case, and a pressing force does not work in a portion away from the central portion.

Also, a structure in which a plurality of prismatic batteries configured in a flat rectangular parallelepiped shape are stacked in the thickness direction between a pair of pressing plates, and the pressing plates are biased by a compression spring in a direction approaching each other. Has been proposed. (Patent Document 2)

With this structure, a pressing force acts evenly on the entire surface of the battery cell, but there is a problem that the structure becomes large and complicated.

Utility Model Registration No. 3183369 JP 2003-36830 A

The problem to be solved by the present invention is to suppress the expansion of a laminate of electrode plates that become the core of a battery cell during power generation in a battery such as a magnesium battery and continuously generate power stably. It is to provide a metal-air battery capable of performing the above.

The present invention
Magnesium, separator, activated carbon, metal are laminated in this order to form a laminate,
One or more of the laminates are arranged densely in the stacking direction;
The laminated body is accommodated in the inner casing of a double casing with a cylindrical shape,
Place the reinforcing plate in the stacking direction on the outside of the inner housing, and place it in the outer housing,
Electric power is generated by injecting an electrolyte into the laminate,
It is a magnesium battery characterized by suppressing that a laminated body swells with progress of a power generation chemical reaction.

The present invention also provides:
Magnesium, separator, activated carbon, metal are laminated in this order to form a laminate,
One or more of the laminates are closely arranged in the stacking direction with an insulating plate sandwiched between the laminates,
A pressing plate and a leaf spring are arranged on at least one side of the laminated body so as to overlap in the laminating direction,
A plurality of the laminated body, the pressing plate, and the leaf spring are housed in a cylindrical casing having a rectangular cross section,
Electric power is generated by injecting an electrolyte into the laminate,
The laminate is always pressed by the pressing plate, and suppresses the swelling of the laminate as the power generation chemical reaction proceeds.

  According to the present invention, the power generation efficiency of the magnesium battery can be improved.

Overall configuration diagram of the first magnesium battery Overall configuration diagram of the second magnesium battery First housing sketch Second housing sketch Layout drawing of laminate Laminate array A sketch of the folded laminate Plan view of leaf spring Figure of uneven structure on the long wall of the housing Figure of uneven structure of the short side wall of the housing Sectional view of tapered wall The figure which shows the state which incorporated the laminated body The figure which shows the state where the layered product is full

FIG. 1 is an overall configuration diagram of the first magnesium battery 1. The magnesium battery 1 includes an array of one or more laminates 2, an inner casing 11 a, a reinforcing plate 16, an outer casing 11 b, and a bottom plate 5. First, the laminated body 2 is arranged in the inner casing 11a, and the reinforcing plate 16 is disposed in close contact with the outer side of the laminated body 2 in the stacking direction, and the whole is inserted into the outer casing 11b. It shows that As shown in the side cross-sectional view of FIG. 3C, the outer dimension of the inner casing 11a and the inner dimension of the outer casing 11b differ by the thickness of the two reinforcing plates 16. The reinforcing plate 16 is inserted into the gap between the inner casing 11a and the outer casing 11b.

As shown in FIG. 5, the laminate 2 is obtained by laminating a magnesium plate 21, a separator 22, activated carbon 23, and a copper plate 24 in the order described. A negative electrode terminal 14 b is attached to the magnesium plate 21, and a positive electrode terminal 14 a is attached to the copper plate 24.

In this embodiment, as shown in FIG. 6, one battery is formed by stacking four stacked bodies 2. An insulating plate 25 made of an insulating material is disposed between the stacked bodies 2 so as not to contact between the stacked bodies 2 and cause electric leakage.

The negative electrode terminal 14b and the positive electrode terminal 14a of each laminate 2 are appropriately connected in series or in parallel, up to four times the voltage generated by one laminate 2, or 4 of the current generated by one laminate 2. You can get up to twice. Moreover, the laminated body 2 can also be directly contacted without using the insulating plate 25, and all the laminated bodies 2 can also be connected in series.

FIG. 3 shows the structure of the housing 11. The casing 11 is basically a cylinder having a rectangular cross section and has no bottom or ceiling. The casing 11 is doubled and includes an inner casing 11a and an outer casing 11b. A bottom plate 5 is fixed to the lower side of the outer casing 11b. The bottom plate 5 has a scallop shape so that it can be seen from the plan view of FIG. 3B, so that air can pass therethrough. A plurality of stacked bodies 2 are arranged inside the inner casing 11a. FIG. 6 shows a state where four stacked bodies 2 are stacked. The inner casing 11a and the outer casing 11b are made of an insulating material, or a material having at least an insulating surface.

On the outer side of the inner casing 11a, reinforcing plates 16 are arranged on both sides in the stacking direction, and the whole is housed inside the outer casing 11a. A bottom plate 5 is fixed to the bottom of the outer casing 11b and is held so that the inner casing 11a and the leaf spring 12 do not fall downward. Further, air can flow through the opening of the bottom plate 5. The reinforcing plate 16 is preferably a metal plate having a large bending stress even if it is thin, particularly a spring steel plate that is difficult to be plastically deformed.

The magnesium battery 1 configured in this manner generates power when an electrolyte is injected into the separator 22 and the activated carbon 23 of the laminate 2.

As the chemical reaction of power generation proceeds, magnesium hydroxide accumulates on the surface of the magnesium plate 21 and the whole expands, creating gaps between the layers of the laminate 2, increasing the internal resistance and degrading the battery performance.

In FIG. 13, the state which looked at the state which the laminated body swelled from the top is shown. FIG. 13 (a) shows a state before the magnesium battery is assembled to generate power (before use). Since the laminate is not full, the cross-sectional shape viewed from above the housing 11 is a rectangular parallelepiped.

If the reinforcing plate 16 and the outer casing 11b are removed from FIG. 13A, a structure without restriction (not shown) can be obtained. FIG. 12B shows a state in which power generation is started (in use) in the case where there is no such reinforcing plate 16 and outer casing 11b (no constraint) and only the inner casing 11a is structured. FIG. 2 shows a state where the laminate 2 is greatly expanded. Since the casing 11 is required to have insulating properties, the casing 11 is made of a plastic material. Therefore, the wall of the casing cannot withstand a large force. The laminated body 2 swells in the direction in which it is laminated, and since the force is not applied to the short side wall of the inner casing 11a, the deformation is small, the force is applied to the long side wall, and the end of the long side wall ( The side closer to the short side wall) is supported by the short side wall, so it does not deform and eventually the center of the long side wall expands greatly.

FIG. 13C shows a case where the reinforcing plate 16 and the outer casing 11b are present (with constraints). Since the reinforcing plate 16 and the outer casing 11b restrain the deformation of the inner casing 11a, the central portion of the long side wall is prevented from expanding. Moreover, since the edge part of the laminated body 2 is supported by the wall of a short side, there is little deformation | transformation. At this time, a pressing force is applied to the entire surface of the laminated body 2 in the direction of the lamination, and a decrease in performance as a battery is suppressed.

In the present embodiment, the presence of the reinforcing plate 16 and the outer casing 11b applies a force to the entire inner casing 11a and thus the entire surface of the laminated body to suppress bloating. Was realized.

A second embodiment will be described with reference to the drawings. FIG. 2 is an overall configuration diagram of the second magnesium battery 1. The magnesium battery 1 has a structure in which the laminated body 2 is arranged, the pressing plate 13 and the leaf spring 12 are stacked and inserted into the housing 11.

As shown in FIG. 5, the laminate 2 is obtained by laminating a magnesium plate 21, a separator 22, activated carbon 23, and a copper plate 24 in the order described. A negative electrode terminal 14 b is attached to the magnesium plate 21, and a positive electrode terminal 14 a is attached to the copper plate 24.

Here, as shown in FIG. 6, a battery in which four stacked bodies 2 are stacked is used as one battery. An insulating plate 25 made of an insulating material is disposed between the stacked bodies 2 so as not to contact between the stacked bodies 2 and cause electric leakage.

The negative electrode terminal 14b and the positive electrode terminal 14a of each laminate 2 are appropriately connected in series or in parallel, up to four times the voltage generated by one laminate 2, or 4 of the current generated by one laminate 2. You can get up to twice. Moreover, the laminated body 2 may be directly contacted without using the insulating plate 25, and all the laminated bodies 2 may be connected in series.

FIG. 4 shows the structure of the housing 11. The casing 11 is basically a cylinder with a rectangular cross section, and has no bottom or ceiling. On one side of the rectangular wall, there is a support projection 15 as shown in the side cross-sectional view of FIG. The support protrusion 15 is for holding the leaf spring 12 at the center of the housing 11 so as not to drop downward, as will be described later.

The inner length L of the short side of the casing 11 shown in FIG. 4C is slightly larger than the sum of the thicknesses of the laminate 2 and the pressing plate 13, and the leaf spring 12 can be installed in the gap.

A bottom plate 5 is fixed to the lower side of the housing 11. The magnesium battery 1 of the present invention is assumed to be used in the posture shown in FIG. At that time, the laminate 2 or the like is blocked by the bottom plate 5 from the cylindrical casing 11 and does not fall down.

The casing 11 is made of an insulating material, or a material having at least a surface insulating property.

The pressing plate 13 has substantially the same size as the laminated surface of the laminated body 2 (a surface parallel to the paper surface in FIG. 5), and has a material, thickness, and structure such as metal or plastic that is less bent by the force of pressing the laminated body 2. Selected.

As shown in FIG. 2, the leaf spring 12 is formed by bending a narrow metal, plastic, or the like into a "<" shape. FIG. 8 is viewed from above so that the bending state of the leaf spring 12 is easy to see. FIG. 8A shows a state in which no force is applied to the leaf spring 12. FIG. 8B shows a state in which the leaf spring 12 is inserted into the housing 11 from the upper side in FIG. 2 together with the pressing plate 13 and the laminated body 2.

At this time, as shown in FIG. 12A, the leaf spring 12 is held against the support protrusion 15 so as not to fall below that position.

1 As can be seen by comparing FIG. 8 (b) with FIG. 8 (a), the leaf spring 12 is deformed, and the “shape” is slightly flattened, and the original shape of FIG. 8 (a) is obtained. In other words, a stress is generated to return to the position, that is, the pressing plate 13 is always pressed rightward in the drawing.

Accordingly, the pressing plate 13 is pressed at almost one point in the central portion, and even the laminated body 2 that is unevenly expanded can be tilted freely, so that it is laminated with almost uniform force over the entire surface. The body 2 can be pressed.

In this state, when an electrolytic solution is injected into the separator 22 and the activated carbon 23, a chemical reaction of power generation occurs, and a current flows through a load connected between the positive electrode terminal 14a and the negative electrode terminal 14b.

When the magnesium plate 21 swells in the laminated body 2 due to a chemical reaction for generating electricity, the leaf spring 12 is further deformed as shown in FIG. It becomes flat and pushes the pressing plate 13 with a stronger force. Therefore, the laminate 2 is pressed more strongly than the beginning, and the decrease in power generation performance is suppressed.

In Example 1, since the laminate 2 can be pressed from the beginning in comparison with the fact that the pressing force becomes stronger after the laminate 2 has expanded to some extent, the power generation performance is reduced from the beginning of the chemical reaction. Suppression can be expected. Moreover, even if the layered body 2 is uneven, the entire surface can be pressed with substantially the same strength.

In Example 3, the four laminated bodies 2 were arranged in an overlapping manner in Example 1 or Example 2, whereas, as shown in FIG. 7, one laminated body 2 was bent three times to obtain four pieces. This is equivalent to stacking the laminated bodies.
In this structure, it is not necessary to provide an electrode in each folded laminated body, and the structure can be simplified. However, it is effective to increase the electric current to be generated, but the voltage cannot be superimposed.
Further, FIG. 7 shows an example in which bending is performed three times to make it equivalent to four laminated bodies. However, as long as it is bent one or more times, the number of bending is not particularly limited.

Other points are the same as those in the first or second embodiment.

In the fourth embodiment, the inner casing 11a has an uneven structure in the first embodiment. FIG. 8 shows a concavo-convex structure in which a plurality of protrusions extending in the vertical direction in FIG. 9C are formed on the long side wall of the housing 11 and the concave portion is used as a reference for the wall thickness. Shows things. FIG. 10 shows a concavo-convex structure in which a plurality of protrusions extending in the vertical direction in FIG. 10C are formed on the short side wall.

The concave portion of the concavo-convex structure does not come into contact with the laminated body 2 even when the laminated body 2 is inserted into the housing 11 and maintains a gap. Therefore, air flows freely, oxygen in the air easily penetrates into the separator 22 and the activated carbon 23, and there is an effect that a chemical reaction for power generation proceeds smoothly.

Further, when the laminated body 2 is housed in the housing 11, it also serves as a passage for a tool for sandwiching or guiding the laminated body 2.

In Example 5, the wall on the long side of the inner casing 11a in Example 4 is tapered such that the surface in contact with the stacked body of the casing is tapered from the upper end to the lower end as shown in FIG. This is the structure.

Thus, by attaching a taper that expands from top to bottom, there is an effect that it is easy to enter when the laminated body 2 is housed in the housing 11, and the laminated body 2 housed inside the housing 11 is There is an effect that makes it difficult to pull out.

DESCRIPTION OF SYMBOLS 1 Magnesium battery 11 Case 11a Inner case 11b Outer case 12 Leaf spring 13 Press plate 14 Positive or negative electrode terminal 14a Positive electrode terminal 14b Negative electrode terminal 15 Support protrusion 16 Reinforcement plate 2 Laminate 21 Magnesium plate 22 Separator 23 Activated carbon 24 Copper plate 25 Insulating plate 4 Uneven structure 5 Bottom plate

Claims (5)

Magnesium, separator, activated carbon, metal are laminated in this order to form a laminate,
One or more of the laminates are arranged densely in the stacking direction;
The laminated body is accommodated in an inner casing of a double casing having a rectangular cross section,
Place a reinforcing plate with a large bending stress on the outside of the inner casing in the stacking direction, and store it in the outer casing.
Electric power is generated by injecting an electrolyte into the laminate,
A magnesium battery characterized by suppressing the expansion of a laminate with the progress of a chemical reaction for power generation. Magnesium, separator, activated carbon, metal are laminated in this order to form a laminate,
One or more of the laminates are closely arranged in the stacking direction with an insulating plate sandwiched between the laminates,
A pressing plate and a leaf spring are arranged on at least one side of the laminated body so as to overlap in the laminating direction,
A plurality of the laminated body, the pressing plate, and the leaf spring are housed in a cylindrical casing having a rectangular cross section,
Electric power is generated by injecting an electrolyte into the laminate,
A magnesium battery characterized in that the laminate is always pressed by the pressing plate, and suppresses expansion of the laminate as the chemical reaction of power generation proceeds. 3. The magnesium battery according to claim 1, wherein the laminate is folded one or more times so as to overlap in the direction of lamination. The magnesium battery according to claim 1, wherein a surface of the housing that contacts the laminated body has an uneven structure. 2. The magnesium battery according to claim 1, wherein a surface of the housing that contacts the laminated body is tapered from the upper end toward the lower end.

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