Microcapacitors

Abstract

To provide a micro capacitor formed between battery electrodes.SOLUTION: A micro capacitor contains hydrogen peroxide, and forms a configuration where a dipole electric double-layer is formed between a cathode electrode formed of metal copper or its alloy and an anode electrode formed of a metal or its alloy having such an electrode potential difference that the electrode potential of the anode electrode is lower than that of the cathode electrode, and electrons flows from the cathode electrode to the anode electrode by a tunnel phenomenon. The micro capacitor causes a current amplification phenomenon similar to avalanche amplification.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a microcapacitor formed on a localized surface area of ​​the cathode electrode to the anode electrode in a battery configuration. As used herein, the term "microcapacitor" refers to an electric double layer formed by an aqueous electrolyte between an electrode protrusion of a cathode electrode and the adjacent surface of an anode electrode. [Background technology]

[0002] In recent years, electric double-layer capacitors have attracted attention as highly responsive storage batteries. They function as compact batteries with excellent instantaneous power, and can withstand rapid charge / discharge cycles and over a million charge / discharge cycles. Therefore, they are being considered as a potential method for improving storage battery performance. Meanwhile, the inventors discovered that in an electrolyte containing hydrogen peroxide, even when the anode and cathode electrodes are placed very close to each other, a dipole electric double layer is formed between the electrodes, preventing short-circuiting even without a separator (Patent Document 1). Therefore, in an effort to apply electric double-layer capacitors to battery construction, the inventors discovered that when the cathode electrode is partially brought close to the anode electrode, an increase in current is observed, resulting in avalanche amplification similar to that observed in photodiodes. Avalanche amplification refers to the phenomenon in which, when light enters a semiconductor light-receiving section with a strong electric field, electrons generated by photon collisions with semiconductor atoms are accelerated, collide with other semiconductor atoms, and further induce multiple electrons. This avalanche-like chain reaction results in an explosive increase in mobile electrons (Non-Patent Document 1). While this phenomenon is unique to semiconductors or insulators, the inventors discovered that a phenomenon similar to this avalanche amplification occurs in metal-air batteries or hydrogen peroxide fuel cell reactions when a microcapacitor is formed between a pair of battery electrodes via a dipole. That is, when multiple microcapacitors are formed between a pair of battery electrodes via a dipole, electrons flow into the microcapacitors from the surrounding cathode electrode, storing electricity. When the cathode electrode is close to a localized portion of the anode electrode via a triangular protruding electrode, electrons begin to flow to the localized portion of the anode electrode due to tunneling, colliding with and erupting other atoms on the electrode, which is thought to cause the avalanche amplification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent application No. 2021-073490 [Non-patent literature]

[0004] [Non-Patent Document 1] "The structure and principles of photodiodes (PD)" by Fiber Labs Co., Ltd. [Non-patent document 2] Eiji Mizuto: Progress in Physical Chemistry (1936), 10(3): 154-165 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide a microcapacitor that can be used in an aqueous battery, which forms a dipole electric double layer at the interface between the electrode and the electrolyte. [Means for solving the problem]

[0006] Hydrogen peroxide, a compound with high dipole efficiency, forms a dipole electric double layer on the electrode surface, preventing short-circuiting even when the cathode and anode are brought into contact. In particular, we discovered that even when an acute-angled triangular protrusion is cut out of the cathode and placed in close contact with a localized portion of the anode, a dipole electric double layer is formed between the cathode and anode, preventing short-circuiting and forming a microcapacitor that stores electrons from the cathode until a predetermined charge is accumulated. When electrons begin to flow from the cathode to the anode due to the tunneling effect, they suddenly concentrate and flow locally at the opposing anode, amplifying the current like an avalanche. The present invention was made based on the above findings, and ―15The microcapacitor comprises an aqueous electrolyte solution containing a dipole having the above dipole efficiency and forming a dipole electric double layer at the interface with the electrode, a cathode electrode made of metallic copper or an alloy thereof, and an anode electrode made of a metal or an alloy thereof that forms an electrode potential difference with an electrode potential lower than that of the cathode electrode, and is characterized in that at least one dipole molecule is sandwiched between the cathode electrode and the anode electrode and has the function of imparting a tunneling effect to the flow of electrons from the cathode electrode to the anode electrode. In particular, a protruding electrode having an acute triangular shape protruding from the cathode electrode surface and at least one 2.0 esu x 10 ―15 A microcapacitor having a dipole efficiency as described above, for example, a dipole electric double layer formed with a hydrogen peroxide molecule, is preferred. [Effects of the Invention]

[0007] The microcapacitor of the present invention is a microcapacitor (FIG. 1) that forms a structure in which electrons flow from the cathode electrode to the anode electrode by tunneling, and generates a current amplification phenomenon similar to avalanche amplification (FIG. 4). Furthermore, hydrogen peroxide acts as a dipole to form a dipole electric double layer on the surface of the cathode electrode, but at the same time, it is present on the surface of the cathode electrode so that it does not short-circuit even when the anode electrode comes into contact with it.The electric dipole also forms an electric double layer capacitor with a current-collecting function, and the multiple electrode protrusions form multiple micro-capacitors between them and the anode electrode.When a certain amount of charge is accumulated through current collection, these scattered micro-capacitors are formed and repeatedly discharge due to the tunneling phenomenon (Figure 3).A conceptual diagram of the equivalent circuit configuration is shown in Figure 4, and it causes the electromotive force change shown in Figure 5. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a conceptual diagram of a microcapacitor of the present invention. [Figure 2] 1 is a conceptual diagram of an air battery to which the microcapacitor of the present invention is applied. [Figure 3]1A is a perspective view of the configuration of a copper electrode that constitutes a microcapacitor of the present invention, and FIG. 1B is a cross-sectional view of the combined state of a magnesium electrode and a copper electrode. [Figure 4] FIG. 1 is a conceptual diagram of a battery in which multiple microcapacitors are formed. [Figure 5] 1 is a graph showing the power generation state when the microcapacitor of the present invention is applied to a magnesium-air battery. [Figure 6] (A) is a perspective view of the structure of the copper electrode of a battery that forms a typical electric double layer capacitor, and (B) is a cross-sectional view of the combined state of the magnesium electrode and copper electrode. DETAILED DESCRIPTION OF THE INVENTION

[0009] In the present invention, as shown in Figure 2, an Mg anode electrode plate and a Cu cathode electrode plate are immersed in an alkaline electrolyte containing hydrogen peroxide and arranged facing each other. As shown in Figure 3(A), a copper electrode 10 is partially cut out into a triangular shape and raised perpendicularly to the electrode surface, forming acute-angled triangular protruding electrodes 11 with a height of 5 to 15 mm. The tips of the protruding electrodes are positioned facing each other so that they softly contact the magnesium electrode surface. A spacing that allows at least one dipole molecule to be interposed between the electrodes is preferable. The protruding electrodes are preferably spaced 150 to 200 mm apart to allow electrons to flow in from the surrounding cathode electrode area.

[0010] The electromotive force in a metal-air battery configuration consisting of an anode electrode, an alkaline electrolyte containing hydrogen peroxide, and a cathode electrode is as follows: The oxidation reaction on the anode side is 2Mg → 2Mg 2+ + 4e - and, On the other hand, the reduction reaction on the cathode side is O2 + H2O + 4e - →4OH - This becomes: In the present invention, hydrogen peroxide is added to the electrolyte to promote the reduction reaction on the cathode side of the metal-air battery, thereby improving the cause of the slower ionization rate at the cathode side positive electrode compared to the anode side negative electrode. That is, metallic copper is Cu + H2O2 → Cu2+ +OH+OH - and Cu+OH→Cu 2+ +OH - and partially dissolves in hydrogen peroxide, Cu 2+ +HO2 - →Cu+2HO2, and the HO2 group is thought to promote the decomposition of hydrogen peroxide via a Haber-Willstatter reaction (Non-Patent Document 2).

[0011] Furthermore, according to the present invention, the electric double layer formed on the surface of the cathode electrode contains hydrogen peroxide and is formed by its dipole function, thereby functioning as an ion-permeable separator. Therefore, the counter anode electrode does not short-circuit even when it comes into contact with the cathode electrode. When the opposing anode and cathode electrodes are contacted with protrusions or the like arranged at regular intervals in a dotted pattern, an electric double layer capacitor structure is formed at the tips of the dotted protrusions (Fig. 1), and many of these are scattered on the electrode surface as microcapacitors, collecting the battery electromotive force and flowing it due to the tunneling effect, repeatedly amplifying it avalanche-wise (Fig. 5). This results in a power generation capacity that is 30% to more than double that of the same electrode configuration without the macrocapacitor function.

[0012] In the present invention, it is preferable to supply part or all of the hydrogen peroxide to the aqueous electrolyte solution by sodium percarbonate. Specifically, it is preferable to add several to several tens of percent of aqueous hydrogen peroxide (volume %) or sodium percarbonate (weight %) to a neutral or alkaline aqueous solution containing 0.5 to 2.0 moles of an alkali metal or alkaline earth metal halide salt, particularly sodium chloride.

[0013] the anode electrode is made of magnesium or its alloy, The battery configuration of (-)Mg / NaCl+H2O2 / Cu(+) provides the decomposition voltage required to decompose hydrogen peroxide or the hydroxyl radicals it decomposes into between the copper cathode and the cathode. MAZ61 or MAZ31 magnesium / aluminum / zinc alloy electrodes can be used as the magnesium alloy electrode.

[0014] The anode and cathode electrodes are alternately arranged facing each other at a fixed interval via spacers, and an electric double layer capacitor is formed by adding an aqueous electrolyte containing hydrogen peroxide to the contact points between the anode and cathode electrodes. The spacers are preferably made of the same metal as the cathode electrodes, copper or copper alloy, and have dot-like protrusions spaced at regular intervals on the surface of the counter electrode (Figure 2). The microcapacitor has a capacitance of 2.0 esu x 10 -15 It is constructed by placing a dipole with the above dipole efficiency, for example, a cathode electrode and an anode electrode facing each other with a distance on the order of nanometers, the distance of one hydrogen peroxide molecule, and a triangular electrode protrudes from the cathode electrode surface so that the tunneling current flows from the cathode electrode to the anode electrode in a concentrated manner. [Example]

[0015] A battery with a microcapacitor based on the concept shown in FIG. 1 was constructed using the copper electrodes shown in FIG. A 3000 ml open-top rectangular plastic container is used. As shown in Figure 2, a copper cathode electrode plate 10, 1 mm thick and 100 x 100 mm long and wide, is provided with numerous triangular protrusions 11, 50 to 100 mm high, cut into it at 150 to 200 mm intervals (Figure 3A). As shown in Figure 3B, the copper plates 10 at both ends have their protrusions 11 facing inward, while the center copper electrode 10 is attached back-to-back so that it protrudes in both directions. A magnesium anode electrode plate 20, 2 mm thick and 100 x 100 mm long and wide, is sandwiched between the two plates. Using this combination electrode, a microcapacitor can be formed on the surface of a copper cathode electrode, as shown in Figure 1. On the other hand, a copper cathode electrode plate 10 measuring 100 x 100 mm and 1 mm thick is cut into a T shape and a spacer S formed by bending the end is attached to it. This cathode electrode plate is then sandwiched between both sides of a 2 mm thick Mg anode electrode plate 20 measuring 100 x 100 mm, with the spacer S in between. Two Mg anode electrode plates 20 are alternately sandwiched between three copper cathode electrode plates 10, with the spacer S in between. Using this combination of electrodes does not form a microcapacitor.

[0016] In a plastic container, prepare an electrolyte solution of 0.5 mol / L or more, preferably 1.5 mol / L to 2 mol / L, of sodium chloride in approximately 1500 mL of pure water, and add 50 to 100 g of sodium percarbonate and 50 mL of 30% hydrogen peroxide solution. After a certain period of time, the hydrogen peroxide will be consumed and the light will decrease, so add 10 ml of 30% hydrogen peroxide every 2 to 3 hours.

[0017] In this example, the performance of the electrode configurations of FIGS. 3A and 3B and 6A and 6B was compared to compare the performance when a microcapacitor was formed on the surface of the copper cathode electrode and when it was not. Since the conditions were the same except for the electrode configuration, the hydrogen peroxide fuel cell reaction in alkaline electrolyzed water was accompanied by a magnesium-air battery reaction. Hydrogen peroxide is H2O2+2H2O+2e - →2H2O+2OH - On the cathode side, H2O2 + 2OH - →O2+2H2O+2e - In addition to the oxidation reaction of Mg → Mg in alkaline electrolyte, 2+ +2e - The reaction of reducing and ionizing oxygen on the cathode side is O2 + 2H2O + 4e - →4OH - A typical metal-air battery reaction occurs. However, while it is understood that oxygen gas is generated in hydrogen peroxide fuel cells and metal-air battery reactions, the above configuration generates not only oxygen gas but also hydrogen gas. This suggests that, as suggested in Non-Patent Document 2 (Mizuto Eiji, Advances in Physical Chemistry (1936), 10(3):154-165), catalytic function operates on the copper cathode electrode surface, causing the decomposition of hydrogen peroxide or hydroxy ions, leading to the power generation reaction. 2H2O2 → 4·OH → H2 + O2 + 4e- 4OH - →H2+O2+4e -

[0018] Considering the above experimental results, it was found that, depending on the configuration of the microcapacitor, a fuel cell with a microcapacitor as shown in Figure 3 showed an increase in current value of more than twice that of a fuel cell without a microcapacitor as shown in Figure 6. It is clear that the current collection and discharge effect associated with microcapacitors has a significant impact on the amount of electricity generated by the battery. Therefore, the configuration of the present invention is groundbreaking because it can provide a new and useful configuration for a single-compartment hydrogen peroxide fuel cell.

Claims

1. 2.0e.su x 10 -１５ In a battery comprising an aqueous electrolyte solution containing hydrogen peroxide, which is a dipolar compound having the above dipole efficiency, and which forms a dipole electric double layer at the interface with the electrode, a cathode electrode made of metallic copper or an alloy thereof, and an anode electrode made of a metal or an alloy thereof which forms an electrode potential difference whose electrode potential is lower than that of the cathode electrode, the cathode electrode has electrode protrusions, and a dipole electric double layer is formed in close proximity to the anode electrode via the electrode protrusions by the electrode protrusions of the cathode electrode, the anode electrode surface, and the aqueous electrolyte solution containing hydrogen peroxide between them, and the microcapacitor has the function of providing a flow of electrons from the cathode electrode to the anode electrode via the dipole double layer.

2. 2. The microcapacitor according to claim 1, wherein the microcapacitor is a dipole electric double layer formed by an acute-triangular protruding electrode protruding from the cathode electrode surface and an aqueous electrolyte solution containing hydrogen peroxide sandwiched between the tip of the protruding electrode and the anode electrode surface.

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