JP2006190522A - Aluminum air solid battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an aluminum air solid battery with little degradation of battery performance. <P>SOLUTION: The aluminum air solid battery has its anode structured of aluminum or an aluminum alloy, its cathode structured of a plurality of air electrodes. and that, the anode, a plurality of cathodes and solid electrolyte are at least partly in a laminated structure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an aluminum air solid state battery using aluminum or an aluminum alloy as a negative electrode active material as a negative electrode and a method for producing the same.

  Since an air battery does not need to be filled with a positive electrode active material in a battery container, it is possible to fill a large amount of space in the battery container with a negative electrode material and a liquid electrolyte. It has the highest energy density, and is characterized by being able to be used for a long time with high output.

  In particular, an aluminum air battery using aluminum as a negative electrode is expected to have a high volume energy density that greatly exceeds that of a zinc-air battery that has been put into practical use. Because it is excellent, it is expected to be put to practical use immediately.

  Details of the aluminum air battery are disclosed in Non-Patent Document 1. A general aluminum air battery uses an aluminum metal for the negative electrode, a liquid electrolyte for the electrolyte, and an air electrode for the positive electrode, which combines oxygen reduction at the air electrode and metal dissolution with electron emission at the metal electrode, In the air electrode and the aluminum electrode, reactions of Formulas 1 and 2 occur, respectively, and hydroxyl ions move through the liquid electrolyte to generate power.

At this time, aluminum hydroxide is generated as a by-product on the negative electrode aluminum electrode, and gelation and non-fluidization occur to inhibit battery discharge, so the capacity and voltage are quickly deteriorated. For this reason, there are almost no examples in practical use in spite of a high volume energy density battery.
(Expression 1) 3/40 ₂ + 3 / 2H ₂ O + 3e ⁻ → 3OH ⁻
(Expression 2) Al + 3OH ⁻ → Al (OH) ₃ + 3e ⁻
On the other hand, Patent Document 1 discloses a solid electrolyte that conducts trivalent metal ions including aluminum ions. Patent Document 2 discloses a technology related to a concentration cell utilizing the fact that trivalent ions represented by aluminum are conducted in a solid. If a solid electrolyte having such properties is used in an aluminum air battery with the positive electrode as an air electrode, a high energy density all-solid aluminum air solid battery in which aluminum ions move through the electrolyte can be constructed. Therefore, it can be widely used for electric vehicles that are small and require high output. There are also safety and maintenance advantages such as no leakage.

However, reports of batteries having such a configuration are not seen as prior art.
Japanese Patent No. 2923769 Japanese Patent No. 3054684 Battery Handbook, p687-688, Asakura Shoten

  The concentration cell using the aluminum ion solid electrolyte disclosed in Patent Document 2 generates an electromotive force due to the difference in aluminum concentration between the electrodes. The electromotive force of the concentration cell is calculated by using the Nernst equation, but the electromotive force is practically only 1 V or less, which is not practical.

  On the other hand, an aluminum air solid state battery having an electromotive force of 1.6 V at which aluminum ions are dissociated from the aluminum metal or an electromotive force exceeding it is obtained by using an aluminum metal as the negative electrode and an aluminum solid electrolyte sandwiched between the positive electrode and the air electrode. It can be analogized that it is obtained.

  When the present inventors actually examined an aluminum air solid battery, an electromotive force of 1.6 V expected from thermodynamic data was not obtained in most cases, and an electromotive force close to 1.6 V was obtained. Even in the obtained case, the electromotive force value is unstable over time, and it is almost difficult to take out the current, and the battery voltage is reduced to nearly zero volts only by flowing a current of several μA per unit area. As it turns out not to work. The present inventors believe that this is the reason why the prior art for an aluminum air solid battery is not found.

As a result of examining the reaction occurring at the electrode, the reason why the aluminum air solid battery does not function is that the discharge inhibiting substance 105 is formed at the interface between the air electrode 103b and the solid electrolyte 101 as shown in FIG. It has been found that the resistance increases and the diffusion rate of oxygen and aluminum ions in the vicinity of the air electrode 103b decreases. In addition, since it is thought that reaction of several 3 and several 4 occurs in the air electrode 103b and the aluminum electrode 102, respectively, it is thought that the discharge inhibiting substance 105 has an alumina as a main component.
(Equation 3) 3/20 ₂ + Al ³⁺ + 3e ⁻ → Al ₂ O ₃
(Equation 4) Al → Al ³⁺ + 3e ⁻
In the case of a solid electrolyte, since it generally operates at a high temperature of 400 ° C. or higher, the method of physically removing the discharge inhibiting substance is mechanically complicated. In addition, since the discharge inhibiting substance is formed on the interface between the air electrode and the electrolyte, it is very difficult to remove by a chemical reaction, and the configuration of the aluminum air solid battery becomes complicated.

  Therefore, a problem for putting an aluminum air solid battery using a solid electrolyte into practical use is to reduce battery performance deterioration due to formation of a discharge inhibiting substance. Here, the battery performance means that a stable electromotive force close to the theoretical voltage is given at the start of discharge, and the amount of voltage drop that occurs as the discharge time increases is small.

  The present invention for solving the performance deterioration due to the discharge inhibiting substance is that the negative electrode and the plurality of positive electrodes are connected via a solid electrolyte, the negative electrode is made of aluminum or an aluminum alloy, the positive electrode is made of a plurality of air electrodes, and An aluminum-air solid battery characterized in that a negative electrode, a plurality of positive electrodes, and a solid electrolyte have a laminated structure at least partially. Thereby, an aluminum air solid state battery with little deterioration of battery performance is realizable.

  According to this configuration, a positive electrode having a large electrode area can be formed in a limited space, and the influence of a discharge inhibiting substance formed at the air electrode-electrolyte interface can be reduced. An air solid state battery can be provided.

  The aluminum solid air battery of the present invention can provide a stable electromotive force close to the theoretical voltage, and can continue to output stably with a small voltage drop.

  The present invention will be described in detail below.

  In order to facilitate understanding of the contents, the manufacturing method will be described first with reference to the drawings.

(Embodiment 1)
FIG. 6 shows a schematic diagram of a method for producing an aluminum air solid battery of the present invention. The negative electrode is indicated by an aluminum electrode 102. The solid electrolyte 101 includes a solid electrolyte 101a and a solid electrolyte 101b. The air electrode 103 serving as a positive electrode is represented by an air electrode 103a and an air electrode 103b. When strict distinction is required, the solid electrolyte 101a may be referred to as a first solid electrolyte 101a, and the solid electrolyte 101b may be referred to as a second solid electrolyte 101b. Similarly, when strict distinction is required for the air electrode 103, the air electrode 103a may be referred to as a first air electrode 103a, and the air electrode 103b may be referred to as a second air electrode 103b.

  A first solid electrolyte 101a shown in FIG. 6 (a) is formed of a solid electrolyte through which aluminum ions propagate, and a projection 111 having a predetermined shape is provided in a predetermined block shape.

  The solid electrolyte 101a can be formed by pressure firing the raw material. The protrusion 111 on the surface may be baked after being molded using a mold in which the protrusion 111 is formed on the surface during pressure molding. Alternatively, after the block-shaped solid electrolyte 101a is first sintered, the recess 112 and the protrusion 111 may be formed by cutting from the upper surface. In addition, in order to reduce an electrical resistance, the surface which produces an aluminum electrode at the next process, and the surface which contact | connects the 2nd solid electrolyte 101b are given.

  Next, as shown in FIG. 6B, the aluminum electrode 102 is formed on the flat surface (lower surface) of the block of the solid electrolyte 101a, and the air electrode 103a is formed on the surface provided with the protrusion 111 of the solid electrolyte 101a. Form. The air electrode 103 a is formed by applying a paste-like air electrode to the recess 112. At this time, it is necessary to expose the protrusion 111 of the solid electrolyte 101a on the upper surface as shown in FIG.

  For simplicity, the air electrode 103a may be formed on the entire solid electrolyte 101a and then polished until the protrusion 111 of the solid electrolyte 101a is exposed on the upper surface.

  The protrusion 111 corresponds to an opening 104 described later.

  Here, since the air electrode 103a is an electrode that requires air (strictly, oxygen), it is preferable that air (strictly speaking, oxygen) is easily diffused into the air electrode 103a as much as possible. For example, a method of selecting a paste composition of the air electrode so as to be a porous electrode, or providing a vent hole from a side surface after forming an electrode or after manufacturing a battery may be used. Here, as shown in FIG. 6D, the air electrode 103a is exposed from the side surface of the aluminum air solid battery, and the air electrode 103b covers the upper surface of the aluminum air solid battery.

  Subsequently, as shown in FIG. 6C, a solid electrolyte 101b is further formed on the air electrode 103a where the solid electrolyte 101a is exposed on the surface. The solid electrolyte 101b may be laminated on the air electrode 103a after being sintered. The solid electrolytes are connected to each other through a portion exposed on the air electrode 103a.

  Next, an air electrode 103b is formed on the solid electrolyte 101b, and an aluminum air solid battery having a configuration as shown in FIG. 6D is completed. In this configuration, an aluminum electrode 102 that is a negative electrode and a plurality of air electrodes 103a and 103b that are positive electrodes are connected, the two air electrodes are connected via a solid electrolyte 101, and an aluminum electrode that is a negative electrode A plurality of air electrodes, which are positive electrodes, and a solid electrolyte are stacked at least partially.

  In FIG. 6C, the solid electrolyte 101b formed on the air electrode 103a may be a solid electrolyte that propagates aluminum ions, and may not be the same as the solid electrolyte 101a as long as it is sufficiently adhered. . In FIG. 6, although the number of air electrodes is two, the step of providing projections 111 and recesses 112 on the surface of the solid electrolyte, the step of forming air electrodes 103 in the recesses 112, and the solid electrolyte 101 thereon It is possible to easily increase the number of the air electrodes 103 by repeating the steps of stacking layers, that is, from FIG. 6A to FIG. 6C.

  The configuration of the present invention may be any configuration in which the air electrode 103a is formed in the solid electrolyte 101, and the effects of the present invention can be obtained regardless of the formation method and shape (square, circle, etc.). For example, in the configuration of FIG. 6C, after the solid electrolyte 101 is sintered first, a cavity for forming the air electrode 103a is formed by processing from the side surface, and the paste-like air electrode is poured into the solid electrolyte. The inner air electrode 103a may be formed.

  FIG. 1 is a schematic diagram (a cross-sectional view taken along line AA ′ in FIG. 6D) of the cross section from the aluminum electrode 102 to the air electrode 103 b of the aluminum air solid battery according to the present invention. The aluminum air solid battery of the present invention includes a solid electrolyte 101a and a solid electrolyte 101b, an aluminum electrode 102, and at least two air electrodes 103a and 103b. The opening 104 is made of a solid electrolyte sandwiched between the solid electrolyte 101a and the solid electrolyte 101b, and corresponds to the protrusion 111 of the solid electrolyte in FIG. In the aluminum air solid battery of the present invention, the aluminum electrode 102, the solid electrode 101a, the air electrode 103a, the aluminum electrode 102, the solid electrolyte 101a, and the opening 104 are connected by connecting the aluminum electrode 102 to the air electrode 103a and the air electrode 103b. -A battery constituted by a solid electrolyte 101b and an air electrode 103b operates.

  The reason why the aluminum air solid battery shown in FIG. 2 (a) does not function is that alumina is formed as a discharge inhibiting substance by the reaction between oxygen and aluminum ions at the interface between the air electrode and the solid electrolyte.

  On the other hand, according to the present invention, the positive electrode is composed of a plurality of air electrodes 103 having a predetermined shape, and the negative electrode, the plurality of positive electrodes, and the solid electrolyte are provided at least in part, thereby increasing the area of the air electrode. Thus, an air battery with a small amount of voltage drop that occurs as the discharge time increases can be obtained. As shown in FIG. 2 (b), it can be seen that by providing the air electrode 103a, the region where the discharge inhibiting substance 105 is formed is remarkably increased as compared with FIG. 2 (a).

  The discharge inhibiting substance 105 is formed at all the interfaces between the air electrode 103a and the solid electrolyte 101a. By changing the area and density of the opening 104 and the thickness and number of the air electrodes 103a, the air electrode 103a. Can be designed.

  The area of the air electrode 103a can be made larger than the area of the air electrode 103b by optimizing the area and density of the openings 104 and the thickness and number of the air electrodes 103a.

  In such a case, in FIG. 2B, the air battery constituted only by the air electrode 103a embedded in the electrolyte has a larger discharge area and the battery performance superior to the air battery constituted only by the air electrode 103b. May have.

  By forming a plurality of air electrodes 103 in the solid electrolyte in this way, an aluminum air solid battery having a plurality of battery performances can be realized while being a single battery.

Here, the meaning of “opening” indicated by reference numeral 104 does not mean that the hole is physically open, but aluminum ions (Al ³⁺ ) move from the aluminum electrode 102 to the air electrode 103b. The opening 104 is embedded with a solid electrolyte, as is apparent from the above description. Note that the material of the solid electrolyte embedded in the opening 104 (that is, the material of the protrusion 111) and the material of the solid electrolyte 101 are preferably the same.

  In the configuration of FIG. 2B, since the opening 104 becomes narrower as the discharge inhibiting substance 105 is generated, the size of the opening 104 is sufficiently negligible for the thickness of the generated discharge inhibiting substance 105. Desirable size is desirable.

  As another configuration for delaying the performance deterioration due to the discharge inhibiting substance, it is easily guessed that it is effective to use an air electrode having a fine shape. FIG. 3A is a schematic diagram when the surface area of the air electrode 103 is increased by such a fine shape. However, in such a configuration, although the initial characteristics are improved, it is not possible to expect deterioration suppression of battery performance in proportion to the increase in surface area.

  This is because, as the reaction at the electrode proceeds as shown in FIG. 3B, the electrode region far from the aluminum electrode is affected by the discharge inhibiting substance 105 formed in the region of the electrode region A close to the aluminum electrode. This is because B does not function. The electrode region B corresponds to a region where the surface area is increased by forming a fine shape.

  In addition to the ceramic materials described in Patent Document 1 and Patent Document 2, the solid electrolyte 101 that propagates aluminum ions of the aluminum-air solid battery of the present invention includes a trivalent metal containing aluminum tungstate and magnesium tungstate, and 2 A trivalent metal, a bivalent metal, and a tetravalent metal tungstate ceramic material containing a tungstate ceramic material, aluminum tungstate, magnesium tungstate, hafnium tungstate, or zirconium tungstate can be used.

  At the interface between the aluminum electrode 102 and the solid electrolyte 101, the aluminum atoms constituting the electrode emit electrons to become trivalent positive ions, and the generated aluminum ions are transported through the solid electrolyte 101 and reach the air electrode. To do. Any substance that generates aluminum ions and electrons by an oxidation reaction can be used for the negative electrode of the aluminum air solid battery of the present invention. Examples of such materials include metallic aluminum, aluminum alloys (Li, Mg, Sn, Zn, In, Pb, Mn, Mo, Co, Cu, Fe, Ni, Bi, Ga, Ti, Cr, Ag, Cd, Au, Nb, Pd, Pt, Si) are particularly preferred because they give a high battery voltage.

On the other hand, the air electrodes 103a and 103b are usually obtained by dispersing manganese oxide, a carbon material, a platinum catalyst, and a polymer in an organic solvent or an aqueous solution to form a paste, and then applying and drying. In addition, any substance that receives electrons generated by the aluminum electrode and reduces oxygen can be used. Perovskite complex oxides such as lanthanum manganite represented by La _(1-x) A _x MnO ₃ (x = 0.95 to 0.05; A = Ca, Sr, Ba), Mn ₂ O ₃ , Mn ₃ O _4, etc. Carbon materials such as manganese lower oxide or activated carbon are preferred because they have both oxygen reducing ability and conductivity.

(Embodiment 2)
In the aluminum air solid battery of the present invention, a function of changing the electrical connection between the plurality of air electrodes 103 can also be added.

  The aluminum air solid state battery shown in FIG. 4 has a configuration comprising a solid electrolyte 101a and a solid electrolyte 101b, an aluminum electrode 102, air electrodes 103a and 103b, and switches 106a and 106b connected to the respective air electrodes. Note that when the switch 106 is required to be strictly distinguished, the switch 106a may be referred to as a first switch 106a and the switch 106b may be referred to as a second switch 106b.

  By closing the switch 106a, the battery constituted by the aluminum electrode 102-solid electrolyte 101a-air electrode 103a operates, and by closing the switch 106b, the aluminum electrode 102-solid electrolyte 101a-opening 104-solid electrolyte 101b- A battery having a circuit constituted by the air electrode 103b operates.

  By switching these switches 106, it is possible to select a substantially necessary area of the air electrode 103, and since the area of the air electrode 103 and the current density are in a proportional relationship, the aluminum air whose current output can be controlled can be selected. A solid battery can be realized.

  Batteries with such a configuration can be used for applications that require a change in current output, such as when a high load is required for a short time, such as when an electric vehicle starts or accelerates, or when the load is small at a constant speed. It is valid.

  Further, since the current output of each battery can be controlled, even when batteries are connected in series as in an electric vehicle to obtain a high voltage, the current output can be controlled by switching the switch.

(Embodiment 3)
FIG. 5 shows an example of a cross-sectional structure and an electrical connection relationship of the aluminum air solid state battery of the third embodiment.

  The aluminum air solid battery shown in FIG. 5 has the aluminum air solid battery shown in FIG.

  The aluminum air solid battery as shown in FIG. 5 can realize a battery having an air electrode area substantially twice that of FIG. 4 and has a battery life almost twice that of FIG. In addition, the current output control can cope with a change about twice that of the battery shown in FIG.

  A battery having such a configuration is preferable for applications that require a change in current output, such as when the load of an electric vehicle changes greatly.

  Hereinafter, specific examples of the present invention will be described.

Example 1
The aluminum air solid state battery having the structure shown in FIGS. 6 and 1 was assembled in the following procedure, and the change in electromotive force at a current of 2 mA was measured at 400 ° C. at intervals of 10 minutes. The size of the battery was about 10 mm square and the height was about 7 mm.

First, Al ₂ (WO ₄ ) ₃ , which is a solid electrolyte of aluminum ions, was prepared. As starting materials, Al ₂ O ₃ (manufactured by Kanto Chemical, purity 99.5%) and WO ₃ (manufactured by high purity chemical, purity 4N) are accurately weighed in a molar ratio of 1: 3, and wet using pure water as a solvent. The mixture was pulverized for 144 hours using a ball mill. After drying all day and night to remove moisture, the obtained raw material powder was calcined at 1000 ° C. to produce a calcined powder. After coarsely pulverizing with reiki, a block having the protrusions 111 shown in FIG. 6 (a) was molded by pressure molding and subjected to main firing at 1100 ° C. for 4 hours. In this example, a 10 mm square block having a thickness of 6 mm provided with protrusions 111 having a 1 mm period of 0.5 mm square and a height of 0.5 mm was produced. The surface where the aluminum electrode 102 is manufactured and the surface where the solid electrolyte 101b is bonded are polished to obtain the solid electrolyte 101a. Although it shrunk slightly during firing, no cracks or cracks occurred and there was no problem.

  Next, as shown in FIG. 6B, an aluminum electrode 102 was formed on the flat surface (lower surface) of the block of the solid electrolyte 101a by the following steps. Specifically, after aluminum electrodes were vacuum-deposited, an aluminum plate having a thickness of 0.1 mm was heated to 630 ° C. while being pressed.

  Further, the air electrode 103a was formed on the surface of the solid electrolyte 101a provided with the protrusions 111 by the following steps. Specifically, the following steps were performed. Manganese oxide, activated carbon and conductive carbon are mixed at a weight ratio of 47:35:12, an appropriate organic solvent is added, platinum powder is added and kneaded, and then the solid electrolyte plate and the block provided with the protrusions 111 are 0.6 mm. The thickness was applied. After sufficiently drying, the surface was polished to expose the protrusion 111 of the solid electrolyte 101a, and the shape shown in FIG. 6B was produced.

Next, in the same manner as described above, a 10 mm square plate having a thickness of 1 mm made of Al ₂ (WO ₄ ) ₃ , which is a solid electrolyte, was prepared, and both surfaces were polished to obtain a solid electrolyte 101b. This was adhered to the solid electrolyte 101a after the production of the air electrode 103a shown in FIG. 6 (b) to produce the structure shown in FIG. 6 (c).

  Next, using the same paste as the air electrode 101a, the air electrode 103b is formed on the solid electrolyte 101b with a thickness of 0.5 mm, and the aluminum air solid battery having a plurality of air electrodes shown in FIG. It was.

  Finally, a 0.3 mm vent hole was formed in each air electrode 103a of the produced aluminum air solid battery from the side surface to ensure good air diffusion.

  Table 1 shows the electromotive force at 400 ° C. of the battery produced through the above steps and the results of the change in battery voltage over time during discharge. In the measurement, a change in electromotive force at a current of 2 mA was measured at intervals of 10 minutes. The electromotive force was measured with the air electrodes 103a and 103b set to the same potential as shown in FIG.

(Comparative Example 1)
As Comparative Example 1, an aluminum air solid battery having only one air electrode having the configuration shown in FIG. An aluminum electrode 102, a solid electrolyte 101, and an air electrode 103 were prepared using the same material and the same method as in Example 1. The solid electrolyte 101 was molded so as to have a height of 7 mm after firing, and after firing, it was polished and used so as to have the same height as the solid electrolyte 101a and the solid electrolyte 101b of Example 1.

(Comparative Example 2)
As Comparative Example 2, an aluminum air solid battery having a single air electrode as in Comparative Example 1 but having a fine shape as shown in FIG. 3 on the surface of the air electrode 103b was produced. An aluminum electrode 102, a solid electrolyte 101, and an air electrode 103 were prepared using the same material and the same method as in Example 1. The solid electrolyte 101 was fired to a height of 7 mm, and then a fine shape was produced on the surface using sandblast. The effective surface area of the air electrode 103b was about twice that of the flat case.

表１に示すように、いずれの場合にも、放電開始直後は熱力学データから予想される１．６Ｖの起電力値が得られているが、比較例１および２の場合には、起電力が著しく低下することが分かった。なお、電流値が同じであるので、単位時間当たりに空気極界面に生成される放電阻害物質の総量がすべて場合において等しいと考えられることから、本実施例のアルミニウム空気固体電池は空気極面積を大きくすることで、起電力の低下を抑制できることがわかった。

As shown in Table 1, in any case, an electromotive force value of 1.6 V expected from thermodynamic data is obtained immediately after the start of discharge, but in the case of Comparative Examples 1 and 2, the electromotive force value is obtained. Was found to be significantly reduced. Since the current value is the same, the total amount of discharge inhibiting substances generated at the air electrode interface per unit time is considered to be equal in all cases, so the aluminum air solid battery of this example has an air electrode area. It was found that the increase in electromotive force can be suppressed by increasing the size.

  On the other hand, in the case of Comparative Example 2, the surface area is about twice that of Comparative Example 1, but the decrease in electromotive force is almost the same as or slightly worse than that of Comparative Example 1. As described above, this is probably because the discharge inhibiting substance is formed in the fine shape and the effect of increasing the surface area due to the fine shape is lost. From this result, rather than simply forming a fine shape and increasing the area of the air electrode, providing a plurality of air electrodes and increasing the surface area of the air electrode may have a significant effect on reducing the electromotive force. all right.

  As described above, it has been found that the battery according to the present invention provides a stable electromotive force at a high temperature and excellent battery characteristics with a small voltage drop during discharge.

(Example 2)
In this example, the electrode extraction method from the air electrode was changed as shown in FIG. 4, and five batteries were produced using the same material and the same method as in Example 1.

  Table 2 shows the results of changes in the electromotive force at 400 ° C. of the battery fabricated in this configuration, the battery voltage during discharge, and the electrode connection. In the same manner as in Example 1, the change in electromotive force at a current of 2 mA was measured at 10 minute intervals.

表２に示すように、空気極からの電極引き出し方法によらず、すべての空気極において、熱力学データから予想される１．６Ｖの起電力を得ることができた。また、空気極１０３ａと空気極１０３ｂを単独で用いた場合を比較すると、電解質中に設けた空気極１０３ａを使用した場合の方が、電圧の経時変化が小さかった。これは空気極１０３ａの方が大きい電極面積を有するためと考えられる。また、空気極１０３ａと１０３ｂを同時に使用した場合は、空気極をそれぞれ単独で使用した場合よりも、さらに電極面積が大きく、電圧の経時変化が小さくなった。

As shown in Table 2, an electromotive force of 1.6 V expected from thermodynamic data could be obtained in all the air electrodes regardless of the method of extracting the electrodes from the air electrode. Further, when the case where the air electrode 103a and the air electrode 103b are used alone is compared, the voltage change with time is smaller when the air electrode 103a provided in the electrolyte is used. This is considered because the air electrode 103a has a larger electrode area. Further, when the air electrodes 103a and 103b were used at the same time, the electrode area was larger and the voltage change with time was smaller than when the air electrodes were each used alone.

  As a result, it has been found that the area of the air electrode to be used can be easily controlled by switching the switch, and the decrease in electromotive force can be suppressed by increasing the electrode area of the air electrode.

  Among the produced aluminum air solid batteries, the fourth battery measured the electromotive force by changing the connection method of the air electrode. First, it was confirmed that the electromotive force had been lowered after 60 minutes of use with the configuration of the air electrode 103b, the switch 106a and the switch 106b were switched, and the electromotive force was measured for 90 minutes with the configuration of the air electrode 103a. By switching this switch, the electromotive force of 1.1 V or more could be maintained for 150 minutes.

  Of the produced aluminum air solid state batteries, the fifth battery measured the change in electromotive force at an interval of 10 minutes with the current being doubled to 4 mA. The air electrode connected both 103a and 103b to the same potential. As a result of this measurement, an electromotive force of 1.22 V was obtained after 60 minutes, and 0.96 V was obtained after 90 minutes. This is thought to be due to the fact that the discharge inhibiting substance is generated approximately twice as compared with Table 2. However, even if the current output is doubled, the influence of the discharge inhibiting substance is within the expected range, and the output density changes. The battery was found to be compatible.

  As described above, the battery according to the present invention can provide a stable electromotive force at a high temperature, and can realize excellent battery characteristics with a small voltage drop during discharge.

  The aluminum-air solid battery according to the present invention can be widely used in electric vehicles that are small and require high output. There are also safety and maintenance advantages such as no leakage.

  The present invention will be summarized below.

1 (FIG. 1) An aluminum air solid having a negative electrode (102) containing aluminum, an air electrode (103), and a solid electrolyte (111) sandwiched between the negative electrode (102) and the air electrode (103) A battery,
The air electrode (103) includes a first air electrode (103a) and a second air electrode (103b),
The solid electrolyte (111) includes a first solid electrolyte (101a) and a second solid electrolyte (101b),
The first solid electrolyte (101a) has a protrusion (111) protruding toward the second solid electrolyte (101b);
A first solid electrolyte (101b) is sandwiched between the negative electrode (102) and the first air electrode (103a),
A second solid electrolyte (101b) is sandwiched between the first air electrode (103a) and the second air electrode (103b),
An aluminum air solid battery in which the protrusion (111) and the first air electrode (103a) are sandwiched between the first solid electrolyte (101a) and the second solid electrolyte (101b).

  2. The aluminum-air solid battery according to item 1, having a plurality of protrusions (111).

  [3] The aluminum-air solid battery according to [1], wherein aluminum ions move through the first solid electrolyte (101a), the second solid electrolyte (101b), and the protrusion (111).

  4. The aluminum-air solid battery according to item 3, wherein the aluminum ions are generated from a negative electrode.

  5 The first air electrode (103a) has a matrix shape, and the plurality of protrusions (111) are respectively sandwiched between the matrix-shaped first air electrodes (103a). The aluminum air solid state battery described in 1.

  [6] The aluminum-air solid battery according to [1], wherein the aluminum ions are made of an electrolyte made of the same material as each of the first solid electrolyte (101a), the second solid electrolyte (101b), and the protrusion (111).

  7 (FIG. 4) The first air electrode (103a) has a first switch (106a), and the second air electrode (103b) has a second switch (106b). The aluminum air solid state battery described in 1.

8 (FIG. 5) having two each of the air electrode (103) and the solid electrolyte (111),
The negative electrode (102) is sandwiched between one air electrode (103) and the other air electrode (103),
The aluminum-air solid battery according to Item 1, wherein the negative electrode (102) is sandwiched between one solid electrolyte (111) and the other solid electrolyte.

8 (Fig. 6)
A method for producing an aluminum-air solid battery having a negative electrode (102) containing aluminum, an air electrode (103), and a solid electrolyte (111) sandwiched between the negative electrode (102) and the air electrode (103). There,
Aluminum air solid battery
The air electrode (103) includes a first air electrode (103a) and a second air electrode (103b),
The solid electrolyte (111) includes a first solid electrolyte (101a) and a second solid electrolyte (101b),
The first solid electrolyte (101a) has a protrusion (111) protruding toward the second solid electrolyte (101b);
Here, the first solid electrolyte (101b) is sandwiched between the negative electrode (102) and the first air electrode (103a),
A second solid electrolyte (101b) is sandwiched between the first air electrode (103a) and the second air electrode (103b),
The protrusion (111) and the first air electrode (103a) are sandwiched between the first solid electrolyte (101a) and the second solid electrolyte (101b),
The manufacturing method includes:
Providing a protrusion (111) and a recess (112) on the surface (upper surface) of the first solid electrolyte (101a);
B. Filling the recess (112) with the first air electrode (103a) and forming a negative electrode (102) containing aluminum on the back surface (lower surface) of the first solid electrolyte (101a);
Forming a second solid electrolyte (101b) on the surface (upper surface) of the first solid electrolyte (101a) from which the first air electrode (103a) and the protrusion (111) are exposed; and Step d of forming the second air electrode (103b) on the surface (upper surface) of the solid electrolyte (101b)
A method for producing an aluminum air solid state battery.

Schematic diagram of a cross-sectional structure of an aluminum air solid battery and a circuit diagram showing an electrical connection relationship in the present invention Operational principle diagram of aluminum solid state battery and electrode configuration sectional view of aluminum air solid state battery of the present invention Working principle diagram of air electrode with fine shape Schematic diagram of the cross-sectional structure of the aluminum air solid state battery in Example 2 of the present invention and a circuit diagram showing the electrical connection relationship Schematic diagram showing an example of the cross-sectional structure and electrical connection relationship of the aluminum air solid state battery of the present invention Schematic diagram of a method for producing an aluminum air solid battery in the present invention

Explanation of symbols

101 Solid Electrolyte 102 Aluminum Electrode 103 Air Electrode 104 Opening 105 Discharge Inhibiting Substance 106 Switch 111 Protrusion 112 Recess

Claims (3)

The negative electrode and the plurality of positive electrodes are connected via a solid electrolyte, the negative electrode is made of aluminum or an aluminum alloy, the positive electrode is made of a plurality of air electrodes, and the negative electrode, the plurality of positive electrodes, and the solid electrolyte are laminated at least partially. An aluminum air solid state battery characterized by having a structure. An aluminum air solid battery characterized in that a negative electrode and a positive electrode are connected via a solid electrolyte, the negative electrode is made of aluminum or an aluminum alloy, and at least one air electrode serving as the positive electrode is present in the solid electrolyte. . 3. The aluminum air solid battery according to claim 1, wherein the electrical connection between the plurality of air electrodes can be changed.

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