TWI683467B - Metal-air battery and method for setting distance between electrodes of metal-air battery - Google Patents

Abstract

High-performance metal-air batteries can be efficiently obtained. The metal-air battery (10) is equipped with a metal electrode (15) and an air electrode (13A), (13B) opposite to the metal electrode (15), and the air electrode (13A), (13B) are respectively arranged on the metal On both sides of the pole (15), the metal pole (15) is arranged close to one of the air poles (13A), (13B) on both sides; the metal pole (15) and the air pole (13A) on one side are The average voltage of the first battery placed between the inter-electrode distance (LA) and the second battery placed between the metal electrode (15) and the other air electrode (13B) at the inter-electrode distance (LB) Is higher than the voltage obtained when the metal electrode (15) is placed at the center of the air electrodes (13A) and (13B) on both sides.

Description

Metal-air battery and method for setting distance between electrodes of metal-air battery

The invention relates to a metal-air battery and a method for setting the distance between electrodes of a metal-air battery.

Generally speaking, in metal-air batteries, the air electrode of the positive electrode and the metal electrode of the negative electrode exist in pairs. In addition, for metal-air batteries, a structure in which air electrodes are arranged at equal distances on both sides of a metal electrode (fuel electrode) has also been proposed (for example, refer to Patent Document 1). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2015-99740

[Problems to be solved by the invention]

However, the metal-air battery mainly reacts on the surface where the air electrode and the metal electrode are opposed, so when the air electrode is only opposed to the single side of the metal electrode, the reaction area of each cell is restricted, and the battery performance is improved. Subject to restrictions. For example, the current density at the time of current flow becomes large, so the result is that it is extremely easy to increase. On the other hand, the structure of Patent Document 1 reduces the current density by increasing the air electrode area of each cell, and as a result, the polarization becomes smaller. However, batteries with higher performance are expected on the market, especially metal-air batteries for disaster prevention, as well as smartphones that can be charged with high current. That is, the metal-air battery must be made smaller.

Here, the object of the present invention is to efficiently obtain a high-performance metal-air battery. [Means for solving the problem]

In order to solve the aforementioned problems, the present invention is a metal-air battery provided with a metal pole and an air pole opposite to the metal pole; characterized in that: the air poles are arranged on both sides of the metal pole; and the metal pole, It is arranged at a position close to one of the air electrodes on both sides; the distance between the metal electrode and the air electrode on one side is the first distance, and the distance between the metal electrode and the air electrode on the other side is the first distance That is, the second distance satisfies the following conditions: the voltage obtained by the first battery in which the metal electrode and the one air electrode are arranged at the first distance, and the metal electrode and the other air electrode in the first distance The average value of the voltage obtained by the second battery arranged at a distance of 2 is higher than the voltage obtained when the metal electrodes are arranged at the center of the air electrodes on both sides.

In the above configuration, the shortest interpole distance is a numerical value LA, the longest interpole distance is a numerical value LB, and the numerical value (LB/LA) may be 2 or more.

In addition, in the aforementioned configuration, it is also possible to have a supporting member that floats and supports the metal electrode from the bottom plate portion of the electric tank that accommodates the metal electrode.

In addition, it is provided with a metal pole and an air pole opposite to the metal pole; the air pole is arranged on both sides of the metal pole; and the metal pole is arranged on one of the air poles near both sides The method for setting the distance between the poles of the metal-air battery at the location is characterized by making the distance between the metal pole and one of the air poles the first distance, and the distance between the metal pole and the other air pole The distance, that is, the second distance, is set to the voltage obtained by the first battery in which the metal electrode and the one air electrode are arranged at the first distance according to the non-linear characteristic showing the relationship between the distance between the electrodes and the voltage, and The average value of the voltage obtained by the second battery arranged at the second distance between the metal electrode and the other air electrode is higher than the voltage obtained when the metal electrode is arranged at the center of the air electrode on both sides higher. [Effect of invention]

According to the present invention, it is easy to obtain a high voltage while ensuring the capacity, and a high-performance metal-air battery can be efficiently obtained.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a metal-air battery 10 according to an embodiment of the present invention, and FIG. 2 is an A-A longitudinal cross-sectional view of FIG. 1. The metal-air battery 10 is equipped with an electric cell 11 (also referred to as a cell). The electric cell 11 is provided with two pieces of air electrodes 13A, 13B and a metal electrode 15. By injecting electrolyte into the electric cell 11 to start power generation Primary battery. When generating electricity, the air electrodes 13A and 13B function as positive electrodes, and the metal electrode 15 functions as a negative electrode. In addition, the symbol UL in FIG. 2 indicates the position of the upper surface of the electrolyte injected into the cell 11.

In addition, the material of the electric cell 11 is not particularly limited, and for example, paper or resin may be used. When the electric cell 11 is made of paper, a thin plate material provided with a film on the surface of the paper constituting the base material is used, and as a specific example, a heat-fusible resin (for example, polyethylene (PE)) may be laminated on at least the inner surface. Of laminated paper. By applying the aforementioned lamination process, leakage of electrolyte and the like can be prevented.

In this description, the directions such as up, down, left, and right correspond to the directions when the metal-air battery 10 is used. The symbol X shown in FIG. 1 and the like shows the front direction, the symbol Y shows the right direction, and the symbol Z shows the upward direction. The X direction coincides with the arrangement direction of the air electrode 13A, the metal electrode 15 and the air electrode 13B. In addition, there are cases where the arrangement direction is changed according to usage conditions and the like.

The electric cell 11 has a thin rectangular shape, and by bending a sheet containing paper, it integrally has a bottom plate portion 21 that constitutes the bottom surface of the electric cell 11, a front wall portion 22 that constitutes the front surface, and a rear wall portion 23 that constitutes the rear surface. The left and right side wall portions (left wall portion and right wall portion) 24 constituting the left and right side surfaces, and the upper plate portion 25 constituting the upper surface. The front wall portion 22 and the rear wall portion 23 are surfaces of the same shape, are arranged in parallel to each other, and form the largest surface in the electrical cell 11, and have rectangular openings 22K of the same shape and size. The opening 22K of the front wall portion 22 is covered with a rectangular air electrode 13A, and the opening 22K of the rear wall portion 23 is covered with a rectangular air electrode 13B.

The air electrodes 13A and 13B are formed in the same shape and the same size, and are respectively arranged on both sides of the metal electrode 15. Each of the air electrodes 13A, 13B has a gas-permeable member that allows the outside air to ventilate into the electric cell 11 and does not allow the electrolyte to leak out, for example, in a rectangular copper mesh constituting the current collector ( (Also referred to as a current collector) Both sides are formed by pressing (punching) the integration of the catalyst sheets constituting the catalyst layer. Each air electrode 13A, 13B is exposed in the electric cell 11 through the opening 22K provided in the electric tank 11, and the area in each opening 22K substantially functions as the air electrode 13A, 13B. In addition, for liquid impermeability, a separate sheet having liquid impermeability may be provided to ensure it. In addition, the air electrodes 13A and 13B are not limited to the above-mentioned configurations, and widely-known configurations can be widely applied.

The current collector is a porous current collector, and has a rectangular copper mesh (copper mesh body), which has good air permeability. The current collector is not limited to copper, but may be other metals such as iron, nickel, and brass. In addition, it is not limited to a porous structure composed of a mesh (mesh), and a porous structure having air permeability other than the mesh can be widely applied. In particular, the copper mesh is suitable for both battery characteristics and cost.

The aforementioned catalyst sheet is a paste in which a conductive agent and an organic substance binding agent are kneaded with water, held in a film made of polyethylene terephthalate (PET) (hereinafter referred to as PET film), and rolled by a roller press Pressed into a thin plate shape and made through a drying step. As the conductive agent, a metal material such as carbon powder, copper or aluminum, or an organic conductive material such as polyphenylene derivative can be used. The carbon powder is preferably a powder using carbon black such as Ketjenblack, graphite, activated carbon, carbon nanotubes, and carbon nanohorns. The organic substance binding agent is a polymer dispersion, specifically, a fluorine-based resin such as polytetrafluoroethylene (PTFE) and Teflon (registered trademark), or a thermoplastic such as polyolefin resin such as polypropylene (PP) Resin is suitable.

The metal electrode 15 is supported in the electric tank 11 by a pair of left and right support members 30 and faces the air electrodes 13A and 13B. The metal electrode 15 is formed of a metal plate made of magnesium alloy, and is arranged parallel to the air electrodes 13A and 13B. For the electrolyte of the metal-air battery 10, a sodium chloride aqueous solution is used. In short, the metal-air battery 10 of this embodiment is a magnesium-air battery. Magnesium-air batteries use seawater for the electrolyte or can be used for tap water mixed with salt liquid, so the scheduling of the electrolyte is easy. In addition, a bag body containing sodium chloride for the electrolyte may be pre-arranged inside the electric cell 11 to generate electricity by simply pouring water such as tap water. The mass of sodium chloride in the electrolyte is preferably 4% to 18% of the mass of the solvent. Because less than 4%, due to insufficient electrolyte, the liquid resistance is large and the performance of the battery cannot be predicted. If it exceeds 18%, the electrolyte will gradually evaporate with the discharge, and the salt will precipitate as a resistance, and the performance of the battery cannot be predicted.

The metal electrode 15 has a pair of left and right ear portions 15A1 extending upward and exposed above the electrolyte. One of the ear portions 15A1 is connected to the electrical wiring 52 (FIG. 3) as a wiring connection portion. In addition, as shown in FIG. 1, the left and right lower ends of the metal electrode 15 are formed with notch portions 15A2 that are notched upward, and the outer shape of each notch portion 15A2 coincides with the outer shape of the ear portion 15A1. Thereby, the upper surface and the lower surface of the metal electrode 15 are formed in the same shape, and when the metal electrode 15 is cut out of a single metal plate (in this case, a magnesium alloy plate), the metal electrode 15 can be continuously cut out without a gap.

In this configuration, when the metal electrode 15 is inserted into the electric cell 11 together with the pair of left and right support members 30, the metal electrode 15 is positioned in the electric cell 11 by the support member 30. Thereby, the metal electrode 15 opposes the air electrodes 13A, 13B exposed inside through the opening 22K, and the separation distance between the air electrodes 13A, 13B and the metal electrode 15, that is, the inter-electrode distance LA, LB is maintained for sure. In addition, the support member 30 may be inserted into the electric cell 11 in advance, and then the metal electrode 15 may be inserted.

The pair of left and right support members 30 are formed of the same member. More specifically, the support member 30 includes a support member body 31 that is detachably attached to the metal pole 15 and extends in the up-down direction (Y direction), and a support member body 31. A plurality (four) of contact portions 41 that protrude and abut against the inner surface of the electric tank 11. Each contact portion 41 includes a pair of upper and lower front extension portions 42 extending forward from the support member body 31 toward the front (+X direction), and an upper and lower pair extending forward from the support member body 31 toward the rear (-X direction) Toward the rear side protrusion 43.

When the supporting member 30 is inserted into the electric tank 11, the protruding surface of the front side protrusion 42 of the supporting member 30 abuts against the front wall portion 22, and the protruding surface of the rear side protrusion 43 abuts against the rear wall portion 23, The front and rear positions of the metal pole 15 supported by the support member 30 are positioned. In addition, the front-side projecting portion 42 also projects on the left and right outer sides and abuts on the side wall portion 24 of the electric cell 11 to position the left and right positions of the metal electrode 15. In this way, the metal pole 15 can be positioned in the cell 11, and the distance LA, LB between the poles can be kept constant. In addition, a pair of left and right support members 30 floats and supports the metal electrode 15 by the bottom plate portion 21 of the electric cell 11.

However, when the metal electrode 15 of the negative electrode active material is a sufficient amount, the battery capacity depends on the amount of water, which is the solvent of the electrolyte. Here, the inventor of the present application is equivalent to an air battery having the same battery capacity, and has conducted various reviews in order to ensure a high power generation voltage at the same time. In this configuration, as shown in FIG. 2, by arranging the metal electrode 15 at one of the air electrodes 13A, 13B on both sides, a high power generation voltage can be obtained while ensuring the capacity. Hereinafter, Examples and Comparative Examples will be described. In addition, the examples are not limited to the following examples.

FIG. 3(A) shows Example 1, FIG. 3(B) shows Comparative Example 1, and FIG. 3(C) shows Comparative Example 2. In addition, FIGS. 3(A) to 3(C) show the cross-sectional structures of the left and right centers of the metal-air battery 10 related to Example 1, Comparative Examples 1 and 2. In each figure, the symbol 51 shows the electrical wiring connected to the air electrodes 13A, 13B, and the symbol 52 shows the electrical wiring connected to the metal electrode 15.

In the first embodiment, the configuration in which the metal electrode 15 is arranged close to the one air electrode 13A can be expressed as an offset type. In this regard, Comparative Example 1 is a structure in which the metal electrode 15 is arranged at the center of the air electrodes 13A and 13B on both sides, and is appropriately represented as a center arrangement type below. In addition, Comparative Example 2 is a configuration in which the right side air electrode 13B is removed in Example 1. In short, it is a single-side type in which the air electrode 13A is arranged only on one side of the metal electrode 15.

FIG. 4 is a graph showing the results (capacity-voltage characteristics) of the constant current discharge test of the aforementioned type 3 metal-air battery 10 under the following conditions. Fig. 4 and the characteristic diagrams shown in the following figures refer to the electric cell 11 having an inner volume of 650 cm ³ and a distance of 26 mm between the air electrode 13A and the air electrode 13B. The result of the discharge test. In addition, saline solution of about 600 cm ³ was injected into the electric cell as an electrolytic solution.

The aforementioned constant current discharge test is a constant current discharge test in which a constant current equivalent to 2A is continuously circulated under a normal temperature (25°C) environment until the battery voltage reaches 0V (the metal electrode 15 is consumed until the battery life). In addition, the horizontal axis in FIG. 4 is the battery capacity [Ah], and the vertical axis is the battery voltage [V]. As shown in FIG. 4, it can be seen that in Example 1, the polarization is smaller than in Comparative Examples 1 and 2, and the polarization is kept very small until the end of the discharge. In Comparative Example 1, the voltage increased compared with Comparative Example 2, but when compared with Example 1, the voltage was very low.

Next, in order to confirm the influence of the inter-electrode distance, the same battery as in Example 1 was used for the test except that the plural types of inter-electrode distances LA and LB were used. The test results are shown in Figure 5 (polarized test) and Figure 6 (constant current discharge test). In the above polarized test, in the state of injecting the electrolyte, in order to make the battery state consistent with the same conditions and activate the reaction, after leaving for 3 minutes, the current connected to the discharge device is equivalent to 10 minutes-2A, and then 3 minutes of rest. Next, the average discharge voltage of the respective current values when the currents of 1.0A, 1.5A, 2.0A, 2.5A, 3.0A, 4.0A, 5.0A, and 6.0A each flowed for 5 minutes was measured. Fig. 5 is a graph showing the current-voltage relationship of various combinations of inter-electrode distances LA and LB. The horizontal axis is current [A] and the vertical axis is average battery voltage [V].

As shown in Fig. 5, the combination of the distance between the poles of 0.5 mm and 22.5 mm at any current value results in a relatively high voltage value. In addition to this combination, according to the order of the combination of the inter-electrode distances of 5.5 mm and 17.5 mm, and the combination of the inter-electrode distances of 9.5 mm and 13.5 mm, good results can be obtained. On the other hand, the combination of the interelectrode distances of 11.5 mm and 11.5 mm corresponding to Comparative Example 2 yielded the lowest voltage at any current value.

According to the review by the inventors of the present application, when the inter-electrode distance is short as the value LA, when the value (LB/LA) is 2 or more, the voltage can be efficiently increased. In addition, when the value (LB/LA) is 2 or more, in the example of FIG. 5, it is a combination of the inter-electrode distance 0.5 mm and 22.5 mm, and a combination of the inter-electrode distance 5.5 mm and 17.5 mm.

Figure 6 is a graph showing the results of a constant current discharge test for various combinations of inter-electrode distances LA and LB. The horizontal axis is the battery capacity [Ah], and the vertical axis is the battery voltage [V]. In addition, the constant current discharge test was performed in the same manner as in Example 1.

As shown in FIG. 6, the battery capacity is almost unchanged in all combinations of the inter-electrode distances LA and LB shown in FIG. This shows that even if the inter-electrode distances are changed as in the various combinations of the inter-electrode distances LA and LB, the effect on capacity is small. However, if the inter-electrode distance LA or LB is excessively narrow, the reaction products accumulate between the air electrodes 13A, 13B and the metal electrode 15, which leads to a decrease in discharge capacity. It can be seen that at least the inter-electrode distance is preferably 0.5 mm or more. By making it 0.5 mm or more, the reaction products accompanying the discharge hardly accumulate between the air electrodes 13A, 13B and the metal electrode 15, which can suppress the The impact of power generation.

Furthermore, the values of the inter-electrode distances LA and LB are preferably set according to the non-linear characteristics exhibiting the relationship between the inter-electrode distance [mm] and the voltage [V]. The method of setting the distance between poles will be described below. FIG. 7 is a graph showing the non-linear characteristic (hereinafter referred to as characteristic curve f1) of the relationship between the distance between electrodes [mm] and the voltage [V]. This characteristic curve f1 is a curve uniquely determined when the air electrodes 13A, 13B and the metal electrode 15 are determined.

By using this characteristic curve f1, as shown in FIG. 7, the voltage VA of the first battery composed of a pair of electrode plates (metal electrode 15 and air electrode 13A) arranged opposite to each other with an inter-electrode distance LA can be calculated. And the voltage VB of the second battery constituted by a pair of electrode plates (metal electrode 15 and air electrode 13B) arranged to face the inter-electrode distance LB. The sum of the calculated values VA and VB can be regarded as the voltage of the metal-air battery 10 shown in FIG. 2 set at the inter-electrode distances LA and LB.

In addition, as shown in FIG. 7, based on the characteristic curve f1, the voltage VC of the battery constituted by a pair of electrode plates (metal electrode 15 and air electrode 13A) disposed opposite to each other with the center-to-electrode distance LC is calculated. The value of twice the calculated voltage VC can be regarded as the voltage of the centrally arranged metal-air battery 10. Next, the distance between the poles LA, LB is set in such a way that the following formula (1) is established.

The aforementioned formula (1) shows that the average value of the voltage VA and the voltage VB is larger than the voltage VC of the central arrangement type. By setting the inter-electrode distances LA and LB in a manner that satisfies this equation (1), a higher voltage can be obtained than that of the central arrangement type.

In short, the inter-electrode distance LA, LB is obtained from the first battery in which the metal electrode 15 and the air electrode 13A are arranged at a distance LA between the electrodes according to the characteristic curve f1 showing the inter-electrode distance-voltage relationship. The voltage VA and the average value of the voltage VB obtained by the second battery in which the metal electrode 15 and the air electrode 13B are arranged at an inter-electrode distance LB are greater than the center of the air electrodes 13A and 13B where the metal electrode 15 is arranged on both sides In the case of position, the voltage VC obtained is set to be higher. With this, the metal-air battery 10 that brings the metal electrode 15 closer to one of the air electrodes 13A, 13B on both sides can easily set the inter-electrode distance LA, LB at which a high voltage can be obtained.

FIGS. 8 and 9 show the electric cell 11 with an inner volume of 350 cm ³ and a separation distance of 14 mm between the air electrode 13A and the air electrode 13B, using a metal-air battery 10 with a metal electrode 15 of 150 mm on all sides and a thickness of 3 mm. The result of the current discharge test. Furthermore, saline solution of about 330 cm ³ was injected into the electric cell 11 as an electrolyte.

Fig. 8 is a graph showing the results of split-pole tests of various other combinations of inter-electrode distances LA and LB, showing the relationship between current value and voltage. In the polarization test, as described above, after being left for 3 minutes, a current equivalent to 10 minutes to 2A was circulated to the discharge device, and then rested for 3 minutes. Next, the average voltage of the respective current values when the currents of 1.0A, 2.0A, 3.0A, 4.0A, 5.0A, and 6.0A each flowed for 5 minutes was measured. FIG. 9 is a graph showing the results of constant current discharge tests of various combinations shown in FIG. 8, the horizontal axis is the battery capacity [Ah], and the vertical axis is the battery voltage [V]. In addition, the constant current discharge test was performed in the same manner as in Example 1.

As shown in FIG. 8, when the combination of the inter-electrode distances LA and LB is the combination of the inter-electrode distances 0.5mm and 10.5mm, and the combination of the inter-electrode distances 4.5mm and 6.5mm, the inter-electrode distances 0.5mm and 10.5 The combination of mm, the combination of the distance between the poles 4.5mm, 6.5mm in order to get a high voltage. On the other hand, the combined voltage equivalent to the center-arranged inter-electrode distance 5.5mm and 5.5mm is the lowest.

As shown in FIG. 9, at all combinations of the inter-electrode distances LA and LB shown in FIG. 8, it is confirmed that the battery capacity is substantially unchanged. That is, as can also be seen from FIG. 8, by arranging the metal electrode 15 on one of the air electrodes 13A, 13B on both sides, a high voltage can be obtained while ensuring the capacity.

As described above, in the metal-air battery 10 of this embodiment, the air electrodes 13A, 13B are arranged on both sides of the metal electrode 15, and the metal electrode 15 is arranged on one of the air electrodes 13A, 13B on both sides. Position, so it becomes easy to secure the capacity while getting a high voltage. That is, a high-performance metal-air battery can be efficiently obtained.

In addition, the distance LA (equivalent to the first distance) between the metal electrode 15 and one of the air electrodes 13A, and the distance LB (equivalent to the second distance) between the metal electrode 15 and the other air electrode 13B satisfy the following conditions of. This condition is the voltage VA obtained by the first battery in which the metal electrode 15 and one air electrode 13A are arranged at the inter-electrode distance LA, and the second battery at the metal electrode 15 and the other air electrode 13B arranged at the inter-electrode distance LB The average value of the obtained voltage VB is higher than the voltage VC obtained when the metal electrode 15 is arranged at the center of the air electrodes 13A and 13B on both sides. By this, a higher voltage can be obtained than the central arrangement type.

In addition, as a method for setting the inter-electrode distance, the inter-electrode distances LA and LB are based on the characteristic curve f1 showing the inter-electrode distance-voltage relationship, so that the metal electrode 15 and the air electrode 13A are arranged at a distance separated by the inter-electrode distance LA. 1 The voltage VA obtained by the battery and the average value of the voltage VB obtained by the second battery in which the metal electrode 15 and the air electrode 13B are arranged at an inter-electrode distance LB are greater than the air electrodes arranged on both sides of the metal electrode 15 The voltage VC obtained in the case of the central positions of 13A and 13B is set to be higher, so that the inter-electrode distances LA and LB at which a high voltage can be obtained can be easily set.

Furthermore, when the short inter-electrode distance is the value LA, and the long inter-electrode distance is the value LB, by setting the value (LB/LA) to 2 or more, the high-voltage inter-electrode distance LA can be more easily set. LB. Furthermore, by setting the numerical value LA of the inter-electrode distance to 0.5 mm or more, the reaction products generated by the discharge hardly accumulate between the air electrodes 13A, 13B and the metal electrode 15, and it is sufficiently easy to suppress the influence on power generation.

In addition, the metal-air battery 10 of the present embodiment includes a pair of left and right support members 30 that float and support the metal electrode 15 by the bottom plate portion 21 of the electric cell 11. Thereby, the accumulation of reaction products accompanying discharge can be suppressed, and at the same time, the convection of the electrolyte can be promoted, and the influence of the reaction products on the battery reaction can be effectively suppressed.

The present invention is not limited to the foregoing embodiments, and various modifications and changes can be made according to the technical idea of the present invention. For example, each part of the metal-air battery 10 including the air electrodes 13A, 13B and the metal electrode 15 may be changed as appropriate. In addition, the metal electrode 15 is not limited to a magnesium alloy, and other materials may be used. Examples of other materials include metals such as zinc, iron, and aluminum, or alloys containing any of these. When zinc is used as the metal electrode 15, a potassium hydroxide aqueous solution may be used as the electrolyte. When iron is used as the metal electrode 15, an alkaline aqueous solution may be used as the electrolyte. In addition, when aluminum is used as the metal electrode 15, an electrolyte solution containing sodium hydroxide or potassium hydroxide may be used.

10: Metal air battery 11: electric tank 13A, 13B: Air pole 15: Metal pole 21: bottom plate 22: Front wall 22K: opening 23: Rear wall 24: side wall 30: Supporting member LA, LB, LC: distance between poles VA, VB, VC: voltage f1: characteristic curve (non-linear characteristic showing the relationship between the distance between electrodes and voltage)

FIG. 1 is a perspective view of a metal-air battery according to an embodiment of the present invention. FIG. 2 is an A-A longitudinal sectional view of FIG. 1. FIG. FIG. 3(A) shows Example 1, FIG. 3(B) shows Comparative Example 1, and FIG. 3(C) shows Comparative Example 2. 4 is a graph showing the results of capacity tests of Example 1, Comparative Example 1 and Comparative Example 2. FIG. Fig. 5 is a diagram showing a split-pole test of various combinations of inter-pole distances LA and LB. Fig. 6 is a graph showing the results of a constant current discharge test for various combinations of inter-electrode distances LA and LB. FIG. 7 is a graph showing the non-linear characteristics of the relationship between the distance between poles [mm] and voltage [V]. Fig. 8 is a graph showing the results of split-pole tests for various other combinations of inter-electrode distances LA and LB. FIG. 9 is a graph showing the results of the constant current discharge test of each combination shown in FIG. 8.

10: Metal air battery 11: electric tank 13A, 13B: Air pole 15: Metal pole 15A1: Ear 21: bottom plate 22: Front wall 23: Rear wall 25: Upper board 31: Support member body 41: contact part 42: Front side extension 43: Rear extension LA, LB: distance between poles

Claims (4)

A metal-air battery is provided with a metal pole and an air pole opposite to the aforementioned metal pole; its characteristics are: The air poles are respectively arranged on both sides of the metal pole; The metal electrode is arranged at a position near one of the air electrodes on both sides; The distance between the metal electrode and the air electrode on one side is the first distance, and the distance between the metal electrode and the air electrode on the other side is the second distance, which satisfies the following conditions: A voltage obtained by a first battery in which the metal electrode and the one air electrode are arranged at the first distance, and a second battery in which the metal electrode and the other air electrode are arranged at the second distance The average value of the voltage is higher than the voltage obtained when the metal electrodes are arranged at the center of the air electrodes on both sides. For example, the metal-air battery in the first item of the patent scope, in which The shortest interpole distance is the value LA, and the longest interpole distance is the value LB, and the value (LB/LA) is 2 or more. If the metal-air battery of the patent application scope item 1 or 2, There is a support member that floats and supports the metal electrode from the bottom plate portion of the electric tank that accommodates the metal electrode. A method for setting the distance between poles of a metal-air battery, comprising a metal pole and an air pole opposite to the metal pole; Arranging the air poles on both sides of the metal poles; The method of setting the inter-electrode distance of the metal-air battery in which the metal electrode is arranged at a position close to one of the air electrodes on both sides is characterized by: The distance between the metal electrode and the air electrode on one side is the first distance, and the distance between the metal electrode and the air electrode on the other side is the second distance, which is set according to the distance between the electrodes and the voltage The non-linear characteristic of the relationship is the voltage obtained by the first battery in which the metal electrode and the one air electrode are arranged at the first distance, and the metal electrode and the other air electrode are arranged at the second distance The average value of the voltage obtained by the second battery is higher than the voltage obtained when the metal electrodes are arranged at the center of the air electrodes on both sides.

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