JP2006040722A - Secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery having a lighter weight and a longer life in comparison with a conventional secondary battery. <P>SOLUTION: An electrode 5a, in which a low resistivity semiconductor layer 2 comprising a semiconductor material insoluble in an electrolyte 13, an ion deposition accelerating layer 6a, and an electrolyte layer 7a are formed in this order on one side of a substrate 1a, and an extraction electrode 9 is connected to the other side through a metallic film 8a, and a coating layer 11a is formed on the surface other than the surface on the low resistivity semiconductor 2 side, and an electrode 5b, in which a low resistivity semiconductor layer 3, a high resistivity semiconductor layer 4 of a semiconductor material insoluble in the electrolyte 13 while having resistance higher than the low resistivity semiconductor layer 2, and an ion deposition accelerating layer 6b are formed in this order on one side of a substrate 1b, and an extraction electrode 10 is connected to the other side through a metallic film 8b, and a coating layer 11b is formed on the surface other than the high resistivity semiconductor layer 4 side, are disposed in a vessel 12 so that the low resistivity semiconductor layer 2 faces the high resistivity layer 4, and the electrolyte 13 is filled between the electrode 5a and the electrode 5b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rechargeable secondary battery utilizing a chemical reaction, and more particularly to a secondary battery in which an electrode is formed of a semiconductor material.

Conventional typical secondary batteries include lead-acid batteries and lithium ion secondary batteries. Lead-acid batteries are currently used for powering automobile engines and electric vehicles. In general, lead dioxide (PbO ₂ ) is used for the positive electrode material and lead (Pb) is used for the negative electrode material. In addition, dilute sulfuric acid (H ₂ SO ₄ ) is used as the electrolytic solution (see, for example, Non-Patent Document 1).

  Further, in the lithium ion secondary battery, a material capable of doping and dedoping lithium ions is used as the positive electrode material, and a carbon material capable of doping and dedoping lithium ions is used as the negative electrode material. (For example, refer to Patent Document 1). In the non-aqueous electrolyte secondary battery described in Patent Document 1, in order to extend the life of a lithium secondary battery, a positive electrode is formed from a lithium-containing compound of cobalt or manganese that can be doped or dedoped with lithium. A solution in which a negative electrode is formed of a non-graphitizable carbonaceous material that can be doped or dedoped with lithium in a non-aqueous electrolyte, and lithium hexafluorophosphate is dissolved in a mixed solution of ethylene carbonate, propylene carbonate, and dimethyl carbonate Is used.

JP 2001-126760 A Hidetoshi Abe and 4 others, “Effect of temperature on the formation of lead-acid batteries”, FB Technical News, November 2003, No. 59, p. 35-40

However, the conventional techniques described above have the following problems. Lead storage batteries as described in Non-Patent Document 1 are currently widely used for automobiles, but the weight of the entire battery is heavy because the specific gravity of lead, which is the main raw material, is as large as 11.4 g / cm ^3. There is a problem. For this reason, the lead storage battery is inconvenient to carry, and the range of applications in which it is used is limited. Moreover, the weight has a considerable influence on the fuel consumption of the automobile and the weight balance of the vehicle body. Furthermore, the lead-acid battery has a problem that it has a life of 2 to 3 years when applied to an automobile and has a short life. In lead-acid batteries, lead sulfate compounds are formed on the electrode surface during repeated normal charge and discharge, resulting in sulfation build-up. In this process, some sulfates are not involved in energy conversion. It enlarges and sticks to the plate. The fixed sulfate reduces the efficiency of the battery and further prevents the battery from functioning.

  On the other hand, lithium ion secondary batteries such as those described in Patent Document 1 have been developed that are lighter and smaller than lead-acid batteries, while cobalt or manganese contained in the positive electrode is being used. There is a problem in that it dissolves in the electrolyte and the capacity gradually decreases.

  The present invention has been made in view of such problems, and an object thereof is to provide a secondary battery that is lighter and has a longer life than conventional secondary batteries.

  The secondary battery according to the present invention is formed of an electrolytic solution, an electrolyte layer that is formed of an electrolyte soluble in the electrolytic solution and arranged to contact the electrolytic solution, and a semiconductor material that is insoluble in the electrolytic solution. A second electrode including a first electrode including the first semiconductor layer, and a second semiconductor layer formed of a semiconductor material that is insoluble in the electrolytic solution and has a work function greater than that of the first semiconductor layer. An electrode, and a pair of lead electrodes connected to the first electrode and the second electrode, respectively, and the first electrode and the second electrode are the first semiconductor layer and the second electrode, respectively. The two semiconductor layers are arranged so as to be in contact with the electrolytic solution.

  In the present invention, since the electrode is formed of a semiconductor material insoluble in the electrolytic solution, the electrode is not dissolved in the reaction process. As a result, the electrode can be made thin and the electrode can be prevented from deteriorating. Therefore, the weight can be reduced and the lifespan can be further reduced as compared with conventional secondary batteries such as lead storage batteries and lithium secondary batteries. become longer.

  A plurality of electrode pairs each including the first electrode and the second electrode are provided, and the first semiconductor layer of one electrode pair and the second semiconductor layer of another electrode pair are connected to each other. Thus, the plurality of electrode pairs are connected in series via the electrolytic solution, and the pair of lead electrodes are connected to the first semiconductor layer and the second semiconductor layer of the electrode pairs at both ends of the series connection body. May be. Thereby, an electromotive force can be increased.

  The first semiconductor layer and the second semiconductor layer may be formed of semiconductor materials having different conductivity types. The second semiconductor layer may have a higher resistivity than the first semiconductor layer. Thereby, the work function of the second semiconductor layer can be made larger than the work function of the first semiconductor layer. At this time, the second semiconductor layer may be formed on a third semiconductor layer having a resistance value lower than that of the second semiconductor layer and having a larger film thickness. It is preferable that the semiconductor layer is connected to the second semiconductor layer via the semiconductor layer so that the third semiconductor layer and the extraction electrode do not come into contact with the electrolytic solution. Thereby, contact resistance can be reduced and charging / discharging efficiency can be improved.

  The first semiconductor layer and the second semiconductor layer may be formed of diamond. Thereby, the life of the battery can be extended. At this time, the first and second semiconductor layers may be doped diamond layers doped with a dopant, and the second semiconductor layer may have a dopant concentration lower than that of the first semiconductor layer. Thereby, the work function of the second semiconductor layer can be made larger than the work function of the first semiconductor layer. The dopant is, for example, boron. Alternatively, the first semiconductor layer and the second semiconductor layer may have different dopant types. At this time, the first semiconductor layer is preferably doped with boron, and the second semiconductor layer is preferably doped with at least one element selected from the group consisting of nitrogen, phosphorus, oxygen, and sulfur. Thereby, the work function of the second semiconductor layer can be made larger than the work function of the first semiconductor layer.

An ion precipitation promoting layer may be provided on at least a part of the surface of the first semiconductor layer or the second semiconductor layer. Thereby, the redox reaction is promoted on the surfaces of the first electrode and the second electrode. Furthermore, the electrolytic solution may contain one kind of compound selected from the group consisting of hydrofluoric acid, weak acid and weak base. Thereby, an oxidation-reduction reaction can be accelerated | stimulated and charging / discharging efficiency improves. In addition, the weak acid in this invention is an acid with a low acidity, for example, in the case of a brainsted acid, the ionization constant K is a thing of less than 10 <^-3> . Similarly, the weak base in the present invention is a base having a low basicity. For example, a brainstead base is a base having a small ionization constant K. Furthermore, the electrolyte may contain at least one selected from the group consisting of lithium, beryllium, boron, sodium, magnesium, aluminum, potassium, calcium and gallium.

  According to the present invention, since the electrode is formed of a semiconductor material that is insoluble in the electrolytic solution, the electrode can be prevented from being deteriorated and the electrode can be made thin, which is lighter than a conventional secondary battery. In addition, the service life can be extended.

  Hereinafter, a secondary battery according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. First, the secondary battery according to the first embodiment of the present invention will be described. FIG. 1 is a cross-sectional view schematically showing the structure of the secondary battery of this embodiment. As shown in FIG. 1, in the secondary battery 20 of the present embodiment, an electrode 5a and an electrode 5b are arranged to face each other in a sealed container 12 made of plastic or the like, and between the pair of electrodes 5a and 5b. The electrolyte solution 13 is filled.

  The electrode 5a in the secondary battery 20 of the present embodiment is insoluble in the electrolytic solution 13 and has a resistivity of 1Ω · on one surface of the substrate 1a made of a semiconductor material or conductor material having a resistivity of 0.01Ω · cm or less. The low resistivity semiconductor layer 2 is formed of a semiconductor material of cm or less. On the other hand, the electrode 5b has a low resistivity semiconductor layer 3 formed on one surface of a substrate 1b made of a semiconductor material or conductor material having a resistivity of 0.01 Ω · cm or less by a semiconductor material having a resistivity of 1 Ω · cm or less. On the low resistivity semiconductor layer 3, the high resistivity semiconductor layer 4 is formed of a semiconductor material that is insoluble in the electrolytic solution 13 and has a resistivity of 50 Ω · cm or more. As the substrates 1a and 1b in the secondary battery 20 of the present embodiment, for example, a semiconductor material such as silicon or a conductive material such as graphite, platinum, and iridium can be used. However, when the substrates 1a and 1b are formed of a metal material such as platinum and iridium, the weight and the manufacturing cost increase. Therefore, when the substrates 1a and 1b are formed of a conductor material, it is preferable to use graphite.

  In addition, ion precipitation promoting layers 6a and 6b are locally formed on the surfaces of the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4, respectively, and the low resistivity semiconductor layer 2 is formed on the electrode 5a. And the electrolyte layer 7a which consists of an electrolyte soluble in the electrolyte solution 13 is formed so that the ion precipitation promotion layer 6a may be covered. Further, metal layers 8a and 8b made of a metal material such as aluminum, silver and tin are formed on the other surfaces of the substrates 1a and 1b, respectively, in order to reduce the contact resistance, and the metal layers 8a and 8b. Are connected to the extraction electrodes 9 and 10, respectively. The thicknesses of the metal layers 8a and 8b are not particularly limited, and may be equal to each other or different from each other. Furthermore, coating layers 11a and 11b made of an epoxy resin are formed on the electrodes 5a and 5b other than the surface on which the ion precipitation promoting layers 6a and 6b are formed so as not to contact the electrolytic solution 13. . The electrodes 5a and 5b are arranged so that the surfaces on which the ion precipitation promoting layers 6a and 6b are formed face each other.

  As described above, in the secondary battery 20 of the present embodiment, the portions of the electrodes 5a and 5b that are in contact with the electrolytic solution 13, that is, the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4, have a mutual resistivity. It is made of different semiconductor materials. Since semiconductor materials having different resistivities have different Fermi levels, their work functions are also different from each other. This is the same whether the doped dopant is the same or different. That is, in the secondary battery 20 of the present embodiment, the work functions of the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 are different from each other. Thereby, a potential difference is generated on the surfaces of the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4, and the electrolyte is dissolved and ionized in the electrolyte solution 13 from the electrolyte layer 7 a on these surfaces, or the electrolyte solution Since an oxidation-reduction reaction occurs in which ions in 13 are deposited on the electrode surface, charging or discharging can be performed.

  At this time, the larger the difference between the work function of the low resistivity semiconductor layer 2 and the work function of the high resistivity semiconductor layer 4, the higher the discharge voltage and the charge pressure. In a conventional secondary battery, in order to obtain a necessary voltage, a plurality of battery cells composed of an electrode pair and an electrolyte filled therebetween are connected in series. Since the number of cells connected in series can be reduced, the size can be further reduced. Specifically, the work function difference between the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 in the secondary battery 20 of the present embodiment is preferably 0.03 to 9 eV, more preferably 0. 0.06 to 5 eV. For example, when the room temperature is 300 K (27 ° C.), the thermal energy at room temperature is about 26 meV. If the work function difference between the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 is smaller than the thermal energy at room temperature, the difference in work function between them is filled with the thermal energy at room temperature. The redox reaction does not occur on the surfaces of the high-rate semiconductor layer 2 and the high-resistivity semiconductor layer 4 and charging / discharging cannot be performed.

  In order to make effective the work function difference between the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 and to proceed the oxidation-reduction reaction on these surfaces, the work function difference is sufficiently higher than the thermal energy at room temperature. Specifically, it is preferably 30 meV or more. In particular, in order to proceed the oxidation-reduction reaction stably even when the room temperature changes, it is preferable to set the difference in work function between the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 to 60 meV or more. Thereby, since the electromotive force can be increased, the overall volume and weight of the secondary battery can be reduced, and the electromotive force can be prevented from being lowered at high temperatures and thermally stabilized. . However, when the electrolytic solution 13 contains water, the work function difference between the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 is preferably 5 eV or less. Thereby, electrolysis of water can be controlled.

  In order to set the difference between the work function of the low resistivity semiconductor layer 2 and the work function of the high resistivity semiconductor layer 4 to 30 meV or more, for example, the resistivity of the high resistivity semiconductor layer 4 is changed to that of the low resistivity semiconductor layer 2. What is necessary is just to make it more than 100 times the resistivity. Further, by making the resistivity of the high resistivity semiconductor layer 4 more than 1000 times the resistivity of the low resistivity semiconductor layer 2, the work function difference between the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 can be reduced. It can be 90 meV or more. Specifically, by setting the resistivity of the low resistivity semiconductor layer 2 to 5 mΩ · cm or less and the resistivity of the high resistivity semiconductor layer 4 to 1 Ω · cm or more, the difference between these work functions is set to 30 meV or more. can do. Further, by setting the resistivity of the low resistivity semiconductor layer 2 to 5 mΩ · cm or less and the resistivity of the high resistivity semiconductor layer 4 to 1000 Ω · cm or more, the difference between these work functions can be set to 90 meV or more. it can. As described above, when the work function difference between the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 is 90 meV or more, the electromotive force is further increased, and the electromotive force is further stabilized thermally. can get.

  In the secondary battery 20 of the present embodiment, the low resistivity semiconductor layer 3 is provided between the high resistivity semiconductor layer 4 and the substrate 1b. In order to increase the current density in the electrodes 5a and 5b, it is preferable to increase these surface areas as much as possible. However, if the surface area is increased, a contact potential drop occurs between the electrodes 5a and 5b and the extraction electrodes 9 and 10. However, the contact resistance increases. Since the increase in contact resistance is greater as the resistivity of the semiconductor layer is higher, it is preferable to provide a low resistivity semiconductor layer between the semiconductor layer and the extraction electrode when the resistivity of the semiconductor layer is high. The contact surface between the semiconductor layer and the extraction electrode is preferably an ohmic junction instead of a Schottky junction. Thereby, contact resistance can be reduced more. Therefore, in the secondary battery 20 of the present embodiment, the low resistivity semiconductor layer 3 having a low resistivity is provided between the high resistivity semiconductor layer 4 and the extraction electrode 10, and the substrate 1b is made of a low resistance conductor material. Alternatively, it is made of a semiconductor material. The lead electrode 10 is connected to the substrate 1b through a metal layer 8b provided on the substrate 1b.

  Further, in order to suppress the power loss in the high resistivity semiconductor layer 4 to the minimum, it is effective to reduce the substantial resistivity by reducing the film thickness and increasing the surface area. In this case, the low resistivity semiconductor layer 3 becomes a support base material for the high resistivity semiconductor layer 4. By using the same material as the low resistivity semiconductor layer 3 on the low resistivity semiconductor layer 3, a high-quality high resistivity semiconductor film is epitaxially grown. However, when the low resistivity semiconductor layer 3 comes into contact with the electrolytic solution 13, a circuit is formed by the high resistivity semiconductor layer 4, the low resistivity semiconductor layer 3, and the electrolytic solution 13, and self-discharge occurs. Layer 3 is kept out of contact with electrolyte solution 13. Specifically, a portion other than the high resistivity semiconductor layer 4 is disposed outside the electrolytic solution 13, or an insulating resin that is resistant to the electrolytic solution 13, such as an epoxy resin, a fluororesin, and a polyethylene resin. Thus, the portion other than the high resistivity semiconductor layer 4 may be covered. Therefore, in the secondary battery 20 of the present embodiment, the coating layer 11 b made of an epoxy resin is provided in a portion other than the high resistivity semiconductor layer 4.

  Each semiconductor layer in the secondary battery 20 of the present embodiment includes, for example, silicon, gallium added with arsenic, indium, aluminum, or the like, gallium nitride, silicon carbide, gallium phosphide, titanium oxide, tin oxide, diamond, aluminum nitride. Boron nitride, boron carbonitride, and the like can be used. The work function of a semiconductor is defined by the difference between the Fermi level energy and the vacuum level. The Fermi level changes depending on the level and concentration of the donor and acceptor, but the change range is limited to the vicinity of the band gap energy. That is, if the materials are the same, the change range of the Fermi level increases as the band gap increases, and the work function difference increases accordingly. Therefore, it is desirable that the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 be formed of a wide gap semiconductor material such as diamond, aluminum nitride, boron nitride, and boron carbonitride.

  Among these wide gap semiconductor materials, it is particularly desirable to form the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 with diamond. Silicon, gallium to which arsenic, indium or aluminum is added, semiconductors such as gallium nitride, silicon carbide and gallium phosphide, oxide semiconductors such as titanium oxide and tin oxide, and electrodes formed by these junctions are When these materials are used, the acid solution and the alkali solution cannot be used as the electrolytic solution. On the other hand, diamond is almost insoluble in acids and alkalis, and this characteristic does not change even when a current is passed, and is chemically stable, so that the life of the battery can be made semipermanent. Furthermore, since diamond has a wide potential window, the voltage at which water electrolysis begins increases, and generation of oxygen and hydrogen during the charge / discharge process can be suppressed. For this reason, a solvent can also be made into water and the choice of the ion seed | species to melt | dissolve and precipitate spreads compared with the conventional secondary battery.

  Next, the characteristics of diamond will be described. Diamond has a wide potential window of 5 V or more and is known as an excellent electrode material. For example, the present inventors have proposed an electrode for electrochemical processing using diamond in Japanese Patent Application Laid-Open No. 2003-73876. In this electrochemical processing electrode, a doped diamond layer doped with a dopant and an undoped diamond layer covering at least a part of the doped diamond layer are provided on the surface of a conductive substrate. Since there are few charge diffusion factors in the undoped diamond layer and charges can be accelerated efficiently, the charge injected into the undoped diamond layer from the surface of the doped diamond layer is accelerated in the undoped diamond layer and then undoped. It is transported to the surface of the diamond layer and promotes the chemical reaction of the object to be processed on the electrode surface. For this reason, when this electrode for electrochemical treatment is used, a substance such as dioxin and phenol, whose decomposition reaction is not promoted unless the potential is higher than the redox reaction of water, can be decomposed. As described above, when an aqueous solution is electrolyzed using an electrode formed of diamond (hereinafter referred to as a diamond electrode), harmful substances can be decomposed at a voltage lower than the voltage at which water is decomposed.

  In addition, studies have been made to apply diamond to a sensor for detecting a component in a solution depending on the width of the potential window. Furthermore, since the diamond electrode is not affected by chemicals such as strong acid and strong alkali, the diamond electrode is superior to the platinum electrode and is expected to be a maintenance-free chemical electrode.

  Furthermore, diamond is a semiconductor with a band gap energy of 5.47 eV, and usually has a high electrical resistivity at room temperature and is equivalent to an insulator. However, it is p-type by doping boron, which is a ternary element. It becomes a conductor, and its resistivity decreases as the boron concentration increases. Further, it is known that a p-type conductor is partially obtained by adsorbing or doping hydrogen or fluorine on the surface. Diamond, on the other hand, is doped with n-type conductivity by doping phosphorus, which is a pentine element, sulfur, which is a genus 6 element, lithium, which is a group 1 element, or introducing lattice defects by a method such as ion implantation. Become a body. Note that although diamond doped with nitrogen is also an n-type conductor, the dopant level is as deep as 1.7 eV or 4 eV, so that it is substantially insulative near room temperature.

  Furthermore, by laminating a boron-doped diamond layer and a non-doped (undoped) diamond layer not doped with a dopant, a rectifier diode and a light-emitting diode superior to a boron-doped diamond single layer can be produced. Note that a rectifier diode and a light-emitting diode can be similarly produced by laminating a diamond layer doped with an n-type dopant such as phosphorus instead of undoped diamond.

  The resistivity of the semiconductor material can be adjusted, for example, by changing the concentration of a dopant that becomes a donor and an acceptor or changing the activation rate. For example, when the semiconductor layer is formed of diamond, the resistivity is about 50 mΩ · cm when doping with 1000 ppm of boron, and the resistivity is about 5 mΩ · cm when doping with 3000 ppm of boron. Further, when the dopant concentration is lowered, the resistance value of the semiconductor layer increases.

When the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 are formed of diamond, for example, the low resistivity semiconductor layer 2 is a highly doped diamond layer doped with a dopant at a high concentration, and the low resistivity semiconductor layer 4 is formed. May be a low-doped diamond layer having a dopant concentration lower than that of the low resistivity semiconductor layer 2. Here, the highly doped diamond layer is, for example, a diamond layer having a dopant concentration of 1 × 10 ^{3 to} 1 × 10 ⁴ ppm, and the dopant concentration in the highly doped diamond layer is 3 × 10 ^{3 to} 6 × 10 ^3. More preferably, it is ppm. By setting the dopant concentration to 1 × 10 ³ ppm or more, the activation rate of the dopant can be remarkably improved, so that the resistance of the semiconductor layer that causes power loss can be reduced. Further, by doping the dopant in a high concentration, for example, when the dopant is a p-type dopant, ie, an acceptor, the work function is maximized, and when the dopant is an n-type dopant, ie, a donor, the work function is minimized. can do. However, when the dopant concentration exceeds 1 × 10 ⁴ ppm, the crystal structure of the semiconductor material is disturbed or the dopant atoms become pairs or lumps, so that the properties as a dopant change.

On the other hand, the low-doped diamond layer is, for example, a diamond layer having a dopant concentration of 1 × 10 ² ppm or less, and the dopant concentration in the low-doped diamond layer is more preferably 10 ppm or less. However, when the dopant concentration is low, it is inevitable that the internal resistance becomes high. Therefore, the low doped diamond layer (high resistivity semiconductor layer 4) has a low dopant concentration as much as possible, and the highly doped diamond layer (low The work function difference from the resistivity semiconductor layer 2) is made large. Specifically, the conductivity type of the low doped diamond layer (high resistivity semiconductor layer 4) and the highly doped diamond layer (low resistivity semiconductor layer 2) is the same, and the highly doped diamond layer (high resistivity semiconductor layer 4). ) Is 1 × 10 ³ ppm or more, the dopant concentration of the low-doped diamond layer (low resistivity semiconductor layer 2) is preferably 100 ppm or less. Thereby, a work function difference of 30 meV or more is obtained. More preferably, the dopant concentration of the highly doped diamond layer (low resistivity semiconductor layer 2) is 3 × 10 ^{3 to} 6 × 10 ³ ppm, and the dopant concentration of the low doped diamond layer (high resistivity semiconductor layer 4). Is 10 ppm or less. As a result, it is possible to reduce the resistance of the highly doped diamond layer (low resistivity semiconductor layer 2) and maximize the work function difference between the low resistivity semiconductor layer 2 and the low resistivity semiconductor layer 3.

  Further, as a dopant doped in diamond forming the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4, it is preferable to use boron which is excellent in the effect of lowering the resistivity and is stable in diamond. Note that the resistivity of the diamond layer can also be lowered by doping hydrogen on or near the surface of the diamond layer. However, in the current technology, the entire diamond layer is made to have a low resistance by a method of doping hydrogen. I can't. Further, the diamond layer doped with hydrogen cannot be used in a battery because the resistivity easily changes due to adsorption of ions on the surface. Furthermore, with elements other than boron, a sufficiently low resistivity cannot be obtained stably.

  In the secondary battery 20 of the present embodiment, the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 may be doped with different dopants. The dopant contained in the semiconductor becomes a factor for forming different Fermi levels depending on the element. That is, the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 are doped with different dopants so that the work functions of the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 are different from each other. be able to.

  Examples of elements that are relatively easily dissolved in diamond include nitrogen, phosphorus, oxygen, sulfur, nickel, lithium, hydrogen, and the like in addition to the above-described boron. Of these elements, it is currently known that boron is an acceptor and nitrogen, phosphorus, oxygen and sulfur are donors. Therefore, for example, one of the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 is doped with boron, and the other is doped with at least one element selected from the group consisting of nitrogen, phosphorus, oxygen, and sulfur. . However, with the current technology, the resistivity of the diamond layer cannot be lowered sufficiently even by doping with an element other than boron. Therefore, in the electrode 5b in which the high resistivity diamond layer 4 is formed on the surface, for example, The low resistivity semiconductor layer 3 is formed of low resistivity diamond doped with boron at a high concentration, and is thinly formed on the low resistivity semiconductor layer 3 and at least one selected from the group consisting of nitrogen, phosphorus, oxygen and sulfur It is preferable to form the high resistivity semiconductor layer 4 made of high resistivity diamond doped with seed elements.

  Further, in the secondary battery 20 of the present embodiment, the ion precipitation promotion 6a is provided on the surfaces of the electrodes 5a and 5b that are in contact with the electrolyte solution 13, that is, on the surfaces of the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4, respectively. And 6b. As the ion precipitation promoting material contained in the ion precipitation promoting layers 6a and 6b, for example, silica, alumina, titania, tin oxide or the like can be used. However, since these ion precipitation promoting materials have high resistivity, the ion precipitation promoting layers 6a and 6b are not formed on the entire surface of the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4, but the low resistivity semiconductor layer. 2 and the high resistivity semiconductor layer 4 are preferably formed so as to have a mesh shape in plan view, for example, so that more than half of the surface of the semiconductor layer 4 is exposed. The ion precipitation promoting materials contained in the ion precipitation promoting layers 6a and 6b may not be the same material as each other, and the ion precipitation promoting material contained in the ion precipitation promoting layer 6a and the ion precipitation promoting material contained in the ion precipitation promoting layer 6b. The promoter may be different from each other.

  In general, these ion precipitation promoting materials are easily dissolved in hydrofluoric acid or buffered hydrofluoric acid, but the present inventors have promoted ion precipitation on the surface of a semiconductor layer having a small work function in the electrode pair. It has been found that by forming a layer, the ion precipitation promoting material becomes difficult to dissolve. Therefore, in the secondary battery 20 shown in FIG. 1, the ion precipitation promoting layer is formed in both the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4, but a solvent in which the ion precipitation promoting material is easily dissolved is used. In the case of using the electrolytic solution containing, it is preferable to form the ion precipitation promoting layer only on the surface of the low resistivity semiconductor layer 2 having a small work function. Thereby, since the ion precipitation accelerating material is dissolved, it is possible to treat a solution that has been considered unapplicable.

  Furthermore, it is preferable that the electrolytic solution 13 in the secondary battery 20 of the present embodiment includes hydrofluoric acid, weak acid, or weak base. When hydrofluoric acid is contained in the electrolytic solution, the energy bands in the vicinity of the surfaces of the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4 are greatly bent, the reaction promoting effect is increased and the current density is improved. However, since hydrofluoric acid has a problem that it is highly toxic, when a hydrofluoric acid solution cannot be used, a solution containing a weak acid such as acetic acid, carbonic acid and organic acid, or aqueous ammonia and soap, which has a relatively low risk. It is preferable to use a solution containing a weak base such as water. Further, since weak acid and weak base have a smaller effect of bending the energy band near the surface of the semiconductor layer than hydrofluoric acid, it is desirable to select an optimal solution as the electrolytic solution 13 according to the application. Moreover, although strong acid solutions, such as hydrochloric acid, and strong base solutions, such as sodium hydroxide, can also be used for the electrolyte solution 13, since these have high volatility and toxicity, they are unpreferable practically. The electrolytic solution 13 may be supported by a gel or the like.

  Furthermore, the electrolyte material forming the electrolyte layer 7a in the secondary battery 20 of the present embodiment is preferably a material that is soluble in the hydrofluoric acid solution, weak acid solution, or weak base solution described above. Group 1 to 3 metals such as lithium, beryllium, boron, sodium, magnesium, aluminum, potassium, calcium and gallium can be used. In particular, from the viewpoint of reducing the weight of the battery, it is preferable to use a metal having a small number of atoms and a small specific gravity.

  In the secondary battery 20 of the present embodiment, the work functions of the surfaces of the electrodes 5a and 5b that are in contact with the electrolytic solution are made different from each other by using semiconductor materials having different resistivities. However, the present invention is not limited to this, and semiconductor materials having different conductivity types may be used. There are two types of semiconductor materials, p-type and n-type, but generally the work functions are different when the conductivity types are different even if the main raw material is the same. Therefore, by forming the surfaces of the electrodes 5a and 5b in contact with the electrolyte using semiconductor materials having different conductivity types, the charges or potentials on the surfaces of the electrodes 5a and 5b can be made unbalanced.

  Further, in the secondary battery 20 of the present embodiment, the low resistivity semiconductor layers 2 and 3 are formed on the substrates 1a and 1b, respectively, but the present invention is not limited to this, and the low resistivity. When the semiconductor layers 2 and 3 have sufficient strength, the substrates 1a and 1b may not be provided. However, when the low resistivity semiconductor layers 2 and 3 are formed of diamond, if the thickness is increased in order to increase the strength, the weight increases. Also, diamond is less likely to have a lower resistance than silicon. Therefore, when the low resistivity semiconductor layers 2 and 3 are formed of diamond, silicon or aluminum having a specific gravity smaller than that of diamond and low resistivity is used as the substrates 1a and 1b, and the low resistivity semiconductor layer is formed thereon. It is preferable to form a thin diamond film as 2 and 3. In particular, since diamond is easily formed on a silicon substrate, when the low resistivity semiconductor layers 2 and 3 are formed of diamond, it is preferable to use a silicon substrate for the substrates 1a and 1b.

  Next, operation | movement of the secondary battery 20 of this embodiment is demonstrated. FIG. 2 is a diagram schematically showing a discharge state in the secondary battery 20 of the present embodiment, and FIG. 3 is a diagram schematically showing a charge state. First, as shown in FIG. 2 and FIG. One end of a resistor 14 and the negative electrode of a constant voltage source are connected to the extraction electrode 9 and one end of a switch 15 is connected to the extraction electrode 10. The other end of the switch 15 is connected to a resistance. 14 or the other positive electrode of the constant voltage source, and when discharging the secondary battery 20 of this embodiment, the other end of the switch 15 is connected to a resistor as shown in FIG. 14 and the lead electrode 9 and the lead electrode 10 are connected via the resistor 14. Thereby, the electrode 5a is formed by the potential difference between the high resistivity semiconductor layer 2 and the low high efficiency semiconductor layer 4. In, from the electrolyte layer 7a into the electrolytic solution 13 The desolate dissolves to produce positive ions 17. The positive ions 17 are deposited on the surface of the high resistivity semiconductor layer 4 of the electrode 5b to form an electrolyte precipitation portion 7b, at which time electrons are transferred to the electrode 5a. From the low resistivity semiconductor layer 2 to the high resistivity semiconductor layer 4 and discharge occurs, and discharge occurs, from the surface of the electrode 5a. When all of the electrolyte layer 7a formed above is dissolved and all the positive ions 17 in the electrolytic solution 13 are deposited on the surface of the high resistivity semiconductor layer 4 of the electrode 5b, the discharge ends.

  On the other hand, when discharging the secondary battery 20 of this embodiment, as shown in FIG. 3, the other end of the switch 15 is connected to the positive electrode of the constant voltage source 15, and the extraction electrode 9 and the extraction electrode 10 are connected. Connect to constant voltage source 15. A predetermined voltage is applied between the extraction electrode 9 and the extraction electrode 10. As a result, the electrolyte layer 7 c formed on the surface of the high resistivity semiconductor layer 4 of the electrode 5 b is dissolved in the electrolytic solution 13 to generate positive ions 17. The positive ions 17 are deposited on the surface of the low resistivity semiconductor layer 2 of the electrode 5a to form an electrolyte deposit 7d. At this time, electrons move from the electrode 5b to the electrode 5a via the constant voltage source 15. That is, the direction 18 of electron movement is from the high resistivity semiconductor layer 4 toward the low resistivity semiconductor layer 4 and is charged. In addition, when all the electrolyte layers 7c formed on the surface of the high resistivity semiconductor layer 4 of the electrode 5b are dissolved, and all the positive ions 17 in the electrolytic solution 13 are deposited on the surface of the low resistivity semiconductor layer 2 of the electrode 5a. Charging ends.

  In the lead-acid battery, the electrode itself is dissolved in the electrolytic solution, so the electrode needs to be thickened to some extent. However, in the secondary battery 20 of the present embodiment, the electrode is formed of a semiconductor material that is insoluble in the electrolytic solution. The electrode can be thinned. The thickness is not limited as long as a defect such as a pinhole is generated, and may be, for example, about 0.1 μm. However, since the mechanical strength is reduced when the electrode is thinned, in the secondary battery 20 of the present embodiment, electrolysis that serves as an electrode is provided on one surface of the substrates 1a and 1b made of a semiconductor or conductor having a low resistivity. By forming the low resistivity semiconductor layers 2 and 3 insoluble in the liquid 13, a predetermined strength is ensured.

Moreover, the secondary battery 20 of this embodiment can be reduced in weight compared with a lead acid battery. For example, each of the semiconductor layers is formed by diamond, when forming a substrate of silicon or graphite, a specific gravity of diamond 3.52 g / cm ^3, the specific gravity of silicon is 2.33 g / cm ^3, the specific gravity of graphite is 2.25g / because cm is ^3, as compared with the lead-acid battery specific gravity as an electrode material using the lead is 11.37 g / cm ^3, it is possible to reduce the weight of the electrode. On the other hand, in a lithium secondary battery, a carbon material such as graphite is used as an electrode material. In a lithium secondary battery, the capacity of the battery is determined by the amount of lithium supported by the electrode. Since the amount of lithium supported depends on the volume of the electrode, the electrode of the lithium secondary battery needs a certain volume, and it is difficult to reduce the thickness and weight as in the secondary battery 20 of the present embodiment. is there.

  Furthermore, since the lead storage battery utilizes the precipitation and dissolution of lead sulfate which is not a conductor, the electrode area is reduced due to the excessive precipitation of lead sulfate, and the efficiency tends to decrease. Since the secondary battery 20 uses precipitation and dissolution of a metal conductor material such as aluminum, even if the amount of precipitation increases, the electrical resistance hardly increases and the efficiency does not substantially decrease. Furthermore, in the secondary battery of this embodiment, since the electrode is formed of a semiconductor material insoluble in the electrolytic solution, the electrode material is dissolved in the electrolytic solution and the electrode is deteriorated as in the lithium secondary battery. There is nothing. As a result, the service life can be extended compared to the conventional secondary battery.

  Next, a secondary battery according to a second embodiment of the present invention will be described. FIG. 4 is a cross-sectional view schematically showing the secondary battery of the present embodiment. As shown in FIG. 4, the secondary battery 30 of this embodiment is obtained by connecting four secondary batteries 20 of the first embodiment shown in FIG. 1 in series. Specifically, an extraction electrode connected to the electrode 5b of the secondary battery 20 which is a single battery and an extraction electrode connected to the electrode 5a of another secondary battery 20 adjacent to the secondary battery 20 are externally connected. It is connected via a connection line 21. And when charging / discharging this secondary battery 30, to the extraction electrode 22 connected to the electrode 5a of the secondary battery 20 located at one end of the unit cell connection body and not connected to the external connection line 21, A switch is connected to a lead electrode 23 connected to one end of the resistor 14 and the negative electrode of the constant voltage source 15 and connected to the electrode 5b of the secondary battery 20 located at the other end and not connected to the external connection line 21. One end of 15 is connected. The other end of the switch 15 is connected to the other end of the resistor 14 or the positive electrode of the constant voltage source 16. Since the secondary battery 30 of the present embodiment has a plurality of unit cells (secondary batteries 20) connected in series, a higher electromotive force can be obtained. Note that the configuration and operation of the secondary battery 30 of the present embodiment other than those described above are the same as those of the secondary battery 20 described above.

  Next, a secondary battery according to a third embodiment of the present invention will be described. FIG. 5 is a cross-sectional view schematically showing the secondary battery of the present embodiment. In FIG. 5, the same components as those in the secondary battery shown in FIGS. 1 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted. In the secondary battery 40 of the present embodiment, a plurality of single cells are connected in series by bonding the substrate 1a and the substrate 1b instead of the external connection line. Specifically, the other surface of the substrate 1a in which the low resistivity semiconductor layer 2, the ion precipitation promoting layer 6a, and the electrolyte layer 7a are formed in this order between the electrode 5a and the electrode 5b. And an electrode 5c having a low-resistivity semiconductor layer 3, a high-resistivity semiconductor layer 4, and an ion precipitation promoting layer 6b formed in this order on the other surface of the substrate 1b are bonded to the low-resistivity semiconductor. A plurality of layers 2 and high resistivity semiconductor layers 4 are arranged so as to face each other. And between electrode 5a, 5b and 5b is satisfy | filled with the electrolyte solution 13, and the several battery cell is connected in series by this. Also in the electrode 5c, a coating layer 11c is formed of a resin material resistant to the electrolytic solution 13 on portions other than the surfaces of the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 4. In the secondary battery 40 of the present embodiment, wiring for connecting each battery cell and a container for partitioning each battery cell are not necessary, so that the weight can be reduced and the manufacturing cost can be reduced. be able to. The other configurations and operations of the secondary battery 40 of the present embodiment are the same as those of the secondary battery 30 shown in FIG.

  Next, a secondary battery according to a first modification of the third embodiment of the present invention will be described. FIG. 6 is a cross-sectional view schematically showing the structure of the secondary battery of this modification. As shown in FIG. 6, the secondary battery 50 of the present modification includes a low resistivity semiconductor layer 3, a high resistivity semiconductor layer 4, and an ion precipitation promoting layer 6 b on one surface instead of the electrode 5 c. An ion deposition promoting layer is formed on the surface of the low resistivity semiconductor layer 3 exposed by removing the substrate after dissolving and removing the central portion of the substrate formed in this order to form a frame 51 to form a membrane structure. 6b and the electrode 5d in which the electrolyte layer 7 is formed in this order are plural so that the high resistivity semiconductor layer 4 and the low resistivity semiconductor layer 3 or the low resistivity semiconductor layer 2 of the electrode 5a face each other. Has been placed. In the secondary battery 50, it is preferable to set the thickness of the low resistivity semiconductor layer 3 to 50 to 100 μm in order to ensure the mechanical strength of the electrode. In the secondary battery 50 of the present modification, instead of the low resistivity semiconductor layer 2, the surface where the high resistivity semiconductor layer 4 of the low resistivity semiconductor layer 3 is not formed is used. Compared to the secondary battery 40 of the third embodiment shown, the overall thickness can be reduced. The other configurations and operations of the secondary battery 50 of the present modification are the same as those of the secondary battery 40 described above.

  Next, a secondary battery according to a second modification of the third embodiment of the present invention will be described. FIG. 7 is a cross-sectional view schematically showing a secondary battery of this modification. As shown in FIG. 7, the secondary battery 60 of this modification includes a low resistivity semiconductor layer 3, a high resistivity semiconductor layer 4, and an ion precipitation promoting layer 6 b on one surface instead of the electrode 5 c. An electrode 5e in which the low resistivity semiconductor layer 2, the ion precipitation promoting layer 6a, and the electrolyte layer 7 are formed in this order on the other surface of the substrate 1 formed in this order is formed of the low resistivity semiconductor layer 2 and the high resistivity semiconductor layer 2. A plurality of resistivity semiconductor layers 4 are arranged so as to face each other. Since the secondary battery 60 of the present modification shares one substrate, it is more than the case where the semiconductor substrates are bonded together like the secondary battery 40 of the third embodiment shown in FIG. , The overall thickness can be reduced. Further, the secondary battery 60 is slightly thicker than the secondary battery 50 having the membrane structure shown in FIG. 6, but the mechanical strength can be improved as compared with the secondary battery 50. The other configurations and operations of the secondary battery 60 of the present modification are the same as those of the secondary battery 40 described above.

  Hereinafter, effects of the embodiment of the present invention will be described in detail. As an example of the present invention, a secondary battery having the structure shown in FIG. 1 was produced. First, an electrode 5a is formed on a p-type silicon substrate having a resistivity of 0.02 Ω · cm by a microwave plasma CVD (Chemical Vapor Deposition) method so that the methane concentration is 1% by volume as a source gas. Using a mixed gas of methane and hydrogen, diborane was added to this raw material gas, and a boron-doped polycrystalline diamond film having a thickness of 3 μm was formed as the low resistivity semiconductor layer 2 while taking care not to generate pinholes. The boron concentration in the boron-doped polycrystalline diamond film was 3000 ppm or more in terms of the concentration ratio (B / C) with respect to carbon atoms.

  Next, after forming 3 μm of boron-doped polycrystalline diamond film as the low resistivity semiconductor layer 3 on the p-type silicon substrate as the electrode 5b by the same method as the above boron-doped polycrystalline diamond film, Use a methane-hydrogen mixed gas with a methane concentration of 1% by volume as a source gas by a microwave plasma CVD method on a polycrystalline diamond film. However, a nitrogen-doped polycrystalline diamond film was formed to a thickness of 0.01 to 0.1 μm as the high resistivity semiconductor layer 4. The nitrogen concentration in the nitrogen-doped polycrystalline diamond film was 1 ppm or less in terms of the concentration ratio (N / C) with respect to carbon atoms. The difference in work function between the boron-doped polycrystalline diamond film as the low resistivity semiconductor layer 2 and the nitrogen-doped polycrystalline diamond film as the high resistivity semiconductor layer 4 was 4.3 eV.

  Next, alumina was deposited on the surfaces of the boron-doped polycrystalline diamond film and the nitrogen-doped diamond film so as to have a thickness of 0.05 to 0.1 μm as an ion precipitation promoting layer, respectively. Then, after forming a resist pattern on the alumina film so as to have a lattice shape in plan view, the alumina film is etched with hydrofluoric acid so that the surfaces of the boron-doped polycrystalline diamond film and the nitrogen-doped diamond film are half the surface area. I was exposed to some extent. Thereafter, aluminum was deposited to a thickness of 10 to 50 μm to form the electrolyte layer 7a so as to cover the boron-doped polycrystalline diamond film of the electrode 5a and the alumina film as the ion precipitation promoting layer.

  Also, aluminum was deposited to a thickness of 0.2 to 0.4 μm on the surface of the electrodes 5a and 5b on the side where the diamond film of the p-type silicon substrate was not formed in order to reduce the contact resistance. And the extraction electrode was connected to this aluminum film. Further, after the portions other than the surface of the boron-doped polycrystalline diamond film and the surface of the nitrogen-doped diamond film in the electrodes 5a and 5b are coated with an epoxy resin, the boron-doped polycrystalline diamond film and the nitrogen-doped diamond film are opposed to each other. In a polyethylene container, a 1% by mass hydrofluoric acid aqueous solution was filled as the electrolytic solution 13 between the electrode 5a and the electrode 5b, and the polyethylene container was sealed.

  Next, one end of the resistor 14 and the negative electrode of the constant voltage source are connected to the lead-out electrode 9 of the secondary battery of the embodiment manufactured by the above-described method, and the other end of the lead-out electrode 10 has the other end. The operation was confirmed by connecting one end of the switch 15 connected to the other end of the resistor 14 or the other positive electrode of the constant voltage source. First, as shown in FIG. 2, the other end of the switch 15 was connected to the other end of the resistor 14, and the extraction electrode 9 and the extraction electrode 10 were connected via the resistance 14. As a result, the electrolyte layer 7a made of aluminum was dissolved, aluminum was gradually deposited on the surface of the nitrogen-doped polycrystalline diamond film, and discharge occurred. At this time, the potential difference between both ends of the extraction electrode 9 and the extraction electrode 10 was about 4V. Then, when all of the electrolyte layer 7a formed on the surface of the electrode 5a is dissolved and all the aluminum ions in the hydrofluoric acid aqueous solution as the electrolytic solution 13 are deposited on the surface of the nitrogen-doped diamond film of the electrode 5b, the discharge is performed. The electric current became zero and the discharge was completed.

  Next, the other end of the switch 15 is connected to the positive electrode of the constant voltage source 15, the extraction electrode 9 and the extraction electrode 10 are connected to the constant voltage source 15, and then between the extraction electrode 9 and the extraction electrode 10. A voltage of 4.5 to 5.0 V was applied. As a result, the aluminum deposited on the surface of the nitrogen-doped polycrystalline diamond film of the electrode 5b was dissolved, and aluminum was gradually deposited on the surface of the boron-doped polycrystalline diamond film of the electrode 5a and charged. Then, all the aluminum deposited on the surface of the nitrogen-doped polycrystalline diamond film of the electrode 5b is dissolved, and all the aluminum ions in the hydrofluoric acid aqueous solution as the electrolytic solution 13 are deposited on the surface of the boron-doped polycrystalline diamond film of the electrode 5a. At the time of deposition, the charging current became zero and charging was terminated.

  This charging / discharging was repeated 1000 times or more. However, the surfaces of the boron-doped polycrystalline diamond film and the nitrogen-doped polycrystalline diamond film were not changed, there was no deterioration, and the life of the secondary battery of this example was semi-permanent. It was.

It is sectional drawing which shows typically the structure of the secondary battery of the 1st Embodiment of this invention. It is a figure which shows typically the discharge state in the secondary battery of the 1st Embodiment of this invention. It is a figure which shows typically the charge condition in the secondary battery of the 1st Embodiment of this invention. It is sectional drawing which shows typically the secondary battery of the 2nd Embodiment of this invention. It is sectional drawing which shows typically the secondary battery of the 3rd Embodiment of this invention. It is sectional drawing which shows typically the secondary battery of the 1st modification of the 3rd Embodiment of this invention. It is sectional drawing which shows typically the secondary battery of the 2nd modification of the 3rd Embodiment of this invention.

Explanation of symbols

1a, 1b; Substrate 2, 3; Low resistivity semiconductor layer 4; High resistivity semiconductor layer 5a, 5b, 5c, 5d, 5e, 110; Electrode 6a, 6b; Ion precipitation promoting layer 7a, 7c; Electrolyte layer 7b, 7d; Electrolyte deposition part 8a, 8b; Metal layer 9, 10, 22, 23; Lead electrode 11a, 11b; Cover layer 12; Container 13; Electrolyte 14; Resistance 15; Switch 16; Constant voltage source 17; Electron moving direction 20, 30, 40, 50; secondary battery 21; external connection line 51; frame 111; conductive substrate 112; doped diamond layer 113; undoped diamond layer

Claims (13)

An electrolyte solution, an electrolyte layer formed of an electrolyte soluble in the electrolyte solution and disposed so as to be in contact with the electrolyte solution, and a first semiconductor layer formed of a semiconductor material insoluble in the electrolyte solution A first electrode; a second electrode including a second semiconductor layer formed of a semiconductor material that is insoluble in the electrolytic solution and has a work function greater than that of the first semiconductor layer; the first electrode; A pair of lead electrodes respectively connected to the second electrode, wherein the first electrode and the second electrode are the first semiconductor layer and the second semiconductor layer are the electrolyte solution. A secondary battery characterized by being arranged so as to be in contact with each other. A plurality of electrode pairs each including the first electrode and the second electrode are provided, and the first semiconductor layer of one electrode pair and the second semiconductor layer of another electrode pair are connected to each other. Thus, the plurality of electrode pairs are connected in series via the electrolytic solution, and the pair of lead electrodes are connected to the first semiconductor layer and the second semiconductor layer of the electrode pairs at both ends of the series connection body. The secondary battery according to claim 1, wherein: The secondary battery according to claim 1, wherein the first semiconductor layer and the second semiconductor layer are formed of semiconductor materials having different conductivity types. 4. The secondary battery according to claim 1, wherein the second semiconductor layer has a higher resistivity than the first semiconductor layer. 5. The second semiconductor layer is formed on a third semiconductor layer having a resistance value lower than that of the second semiconductor layer and a thickness of the second semiconductor layer, and the lead electrode is interposed through the third semiconductor layer. The secondary battery according to claim 4, wherein the secondary battery is connected to a second semiconductor layer, and the third semiconductor layer and the extraction electrode do not contact the electrolytic solution. The secondary battery according to claim 1, wherein the first semiconductor layer and the second semiconductor layer are formed of diamond. 7. The first semiconductor layer and the second semiconductor layer are doped diamond layers doped with a dopant, and the second semiconductor layer has a dopant concentration lower than that of the first semiconductor layer. Secondary battery described in 1. The secondary battery according to claim 7, wherein the dopant is boron. The secondary battery according to claim 7, wherein the first and second semiconductor layers have different dopant types. The first semiconductor layer is doped with boron, and the second semiconductor layer is doped with at least one element selected from the group consisting of nitrogen, phosphorus, oxygen, and sulfur. The secondary battery according to 9. 11. The secondary battery according to claim 1, wherein an ion precipitation promoting layer is provided on at least a part of a surface of the first semiconductor layer or the second semiconductor layer. 11. . The secondary battery according to claim 1, wherein the electrolytic solution includes one compound selected from the group consisting of hydrofluoric acid, weak acid, and weak base. 13. The electrolyte according to claim 1, wherein the electrolyte contains at least one selected from the group consisting of lithium, beryllium, boron, sodium, magnesium, aluminum, potassium, calcium, and gallium. Secondary battery.

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