ES2554988A2 - Electrochemical energy storage device - Google Patents

Abstract

The present invention relates to a metal-air battery that works at high temperatures, said battery comprising a metal-containing electrode, wherein preferably the metal is in molten, solid, or semi-solid state a porous air electrode comprising a mixed electron and oxygen ion conductor and a solid oxide electrolyte being electronically isolator and oxygen ion conductor, methods for its preparation and its use as power source of small devices as well as a power source for automotive applications and as an energy storage device for utility applications as well as for automotive and power electronic applications.

Description

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DESCRIPTION

Electrochemical storage device from Jan ^ a Field of the invention

The present invention relates to an electrochemical cell with an exceptionally high energy density and long operating life. In particular, it refers to a high-temperature metal-air battery that includes a negative metal electrode, a positive air electrode and a solid oxide electrolyte that is a conductor of oxygen ions. The invention also relates to particular designs of modular electrochemical cells.

Background

Rechargeable batteries, or secondary ones, have been widely used for electronic, stationary and automotive applications. They have been identified as one of the most important facilitating technologies in the 21st century due to their significant roles in a green and sustainable energy future. There are many types of rechargeable batteries such as lead-acid, nickel-cadmium, metal-hydride, vanadium redox flux, sodium-sulfur and lithium-ion batteries. Among them, Li-based battery is one of the most advanced and has found wide applications in the last twenty years. However, current batteries do not meet demand in terms of energy, power, safety, life and cost. Future batteries will need new chemical compounds, innovative material concepts and manufacturing techniques and revolutionary cell design.

One of the possible future systems is a metal-air battery such as Li-air or Zn-air, although Zn-air is usually not rechargeable. A lithium-air battery typically includes a negative lithium metal electrode (or anode), a positive electrode (or cathode) in which the reaction with oxygen occurs (for example, from the air, sometimes referred to as an "electrode oxygen positive ”), and an electrolyte or other medium that conducts ions in fluid communication with both the positive electrode and the negative electrode. Normally, lithium and oxygen react to produce lithium oxides.

During discharge, lithium ions flow from the negative electrode through the electrolyte and / or the medium that conducts ions to react with oxygen in the positive electrode to

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forming a product such as lithium oxide (LiO2) or lithium peroxide (Li2O2) that is deposited on the positive electrode. This is coupled with the flow of electrons from the negative to the positive electrode through a charging circuit, which can be used to produce power. The system has a discharge voltage of approximately 2.7 V. Theoretically, an energy density of more than 11000 Wh / kg can be provided, however, in practice it will be much lower due to many issues.

One of the main issues with the conventional Li-air battery is the low capacity for recycling and utilization of the lithium anode. After decades of research and development, only a few hundred cycles have been achieved for rechargeable lithium batteries. With repeated removal and redeposition of lithium in the anode, a dendrite of high surface area tends to form. This not only reduces the efficiency of the cyclization, due to the reaction with the electrolyte to form resistive electrolyte-solid (SEI) contact surface layers, but also has a serious safety problem due to the possibility of thermal instability. Unless the efficiency of lithium cycling is improved, conventional Li-air batteries will have a hard time competing with lithium-ion batteries. It has been estimated that with a three-fold excess of lithium, the volumetric energy density of the Li-air battery is even slightly lower than that of the current Li-ion battery. Therefore, research groups are conducting a tremendous amount of research work to improve the performance of the lithium electrode (Kraytsberg, A. et al., Journal of Power Sources, 2011, 196, 886-893; Girishkumar, G. et al., J. Phys. Chem., 2010, 1, 2193-2203). One of the approaches is to limit the contact between the liquid electrolyte with the lithium anode. Visco et al. (US2007 / 117007; US2007 / 172739; WO2007 / 062220; WO2007 / 075867 and WO2010 / 005686) used a protective membrane architecture that conducts Li ions but is electrolyte, moisture and air impermeable. It would still be a huge challenge to make the conventional Li metal anode have thousands of cycles for applications in cars and public services.

Another main issue with the conventional Li-air battery with organic electrolyte is the air cathode. As lithium oxide reaction products are formed, they often block the pores of the cathode and effectively stop the electrode reaction. As a result, most cell voltage decrease occurs in the air cathode (Kraytsberg, A. et al., Journal of Power Sources, 2011, 196, 886-893). To improve the performance of the air cathode, researchers have been developing advanced catalysts in order to reduce cathode overvoltage and increase the reversibility of the reaction. Attention should also be paid to the cathode architecture

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to maintain adequate transport of oxygen and Li ions to the reaction sites and at the same time provide sufficient space to house solid oxide products (Kraytsberg, A. et al., Journal of Power Sources, 2011, 196, 886- 893).

Due to the design, architecture and materials used for the different components that make up the Li-air batteries described in the state of the art, they are not yet competitive with other conventional lithium batteries, and therefore their use has not been used for applications in cars and public services. Therefore, it is desirable to develop new battery systems that primarily address the low efficiency of the metal anode and the blocking of the pores in the air cathode electrode.

On the other hand, solid oxide fuel cells (SOFC) have been developed as a promising technology that converts the chemical energy of a fuel into electricity through a chemical reaction with oxygen. The main characteristic of a solid oxide fuel cell is its solid electrolyte which is an oxygen conductor. It also has a cathode and an anode in which half of the cell reactions take place. In the cathode, oxygen is reduced to oxygen ions that are then transported to the anode through the solid electrolyte under electric charge. In the anode, oxygen reacts with fuels that contain hydrogen to form water.

A particular solid oxide fuel cell that can be mentioned is one that contains a liquid tin anode to direct the generation of energy from carbon or JP8 fuels (Tao, T. in SOFC-IX, SC Singhal and J. Mizusaki Editors , Quebec City, Canada, 2005, pages 353-362; Tao, T. et al., ECS Transactions, 2007, 12, 681-690; McPhee, WAG et al, Energy & Fuels, 2009, 23, 5036-5041 ; Koslowske, MT et al., Advances in Solid Oxide Fuel Cells V, 2009, 30; Tao, T. et al., ECS Transactions, 2009, 25, 1115-1124). In such a system, tin is used as a liquid layer that completely covers the area of active oxygen exchange between the electrolyte and the anode. In particular, the liquid anode participates as an intermediary for the oxidation of fuel supplied to the fuel cell. The anode serves as a buffer against fuel contaminants, as it blocks the transport of insoluble constituents or slag formation to the electrolyte and prevents the transport of soluble fuel contaminants, thus reducing the rate of reactions between the contaminant and the electrolyte. It is also proposed that the efficiency of use of the electrolyte surface is improved with respect to the existing porous solid anode technology because the liquid layer completely covers the electrolyte. Therefore, oxygen reactions can be expected throughout

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the surface of the electrolyte when a liquid anode is used, instead of just around triple phase kmites between the fuel, the anode and the electrolyte. Jayakumar et al. (J. Electmchem. Soc., 2010, 157 (3), B365-B369) reported such a device in which the Sn and Bi were examined at 973 and 1073 K for use as anodes in fuel cells solid oxide with zircona electrolyte stabilized with yttria (YSZ). Although the open circuit voltages were close to what was expected based on their oxidation thermodynamics, their intention was to use molten metal as a means to transfer oxygen to solid fuels such as carbon. Therefore, these systems were still used as energy conversion devices.

WO03 / 001617 and WO01 / 80335 describe rechargeable devices that have a dual mode capability, since such devices can function as a fuel cell and as a battery, and include a liquid metal anode, an electrolyte and a cathode. However, it is necessary to recharge them with a chemical source in order to operate dually and only act as a battery providing electrical power for a short period of time when the fuel supply (chemical source) has been depleted or interrupted. Therefore, these systems cannot be considered as an electric energy storage device, and even less with improved properties with respect to currently available metal-air batteries, as provided by this invention.

Brief Description of the Invention

The authors of the present invention have found that a metal-air battery in which oxygen ions diffuse through a solid oxide electrolyte between electrodes and in which the metal anode operates in a molten or semi-molten state, allows them to have place electrochemical reactions and overcome the problems arising from the use of conventional metal-air batteries of the technique.

The metal-air battery of the invention combines the technology of conventional metal-air batteries with that of solid oxide fuel cells to provide a high energy system for many applications in public services. This battery operates at high temperature, usually between 300-1000 ° C.

In particular, it uses the cathode and solid oxide fuel cell electrolyte (SOFC) and a fuel containing metal stored in the metal-air batteries. Without

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However, the electrochemical reactions that take place in the new battery system are completely different from those in the metal-air or SOFC batteries as shown below.

Unlike other electrochemical devices that combine the technology of metal-air batteries with that of solid oxide fuel cells, the battery of the invention can only be recharged electrically and used as an electrical energy storage device.

More particularly, the invention provides a metal-air battery system with energy density greater than that of lithium ion batteries due to the high efficiency of metal use. In addition, the use of a solid oxide electrolyte significantly reduces the portion of electrolyte in the system when compared to other metal-air batteries in which up to 70% of the weight is electrolyte. This also results in higher energy densities.

As an additional advantage, it has a longer life than conventional Li-air cells, since lithium dendrite is not formed. The absence of dendrite formation also prevents short circuits and thermal instability, thus making the metal-air battery system of the invention safer than conventional lithium-based batteries.

In particular, the metal-air battery of the invention can be charged and discharged electrically for more than 1000 cycles without any type of fuel or chemical source, thus producing a choulombic efficiency of approximately 1.

Due to the high energy density, as a result of the high charge and use of the metal anode, and the long cycle life, the cost per kWh of energy is expected to be comparable to, or less than, the Li-batteries conventional air or lithium ion.

The metal-air battery of the invention is also rechargeable and therefore can be used as an energy storage device.

Compared to solid oxide fuel cells, it uses a stored metal fuel instead of conventional gaseous fuels and therefore does not need a fuel distribution system. In addition, the temperature of

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Operation can potentially be reduced and the power density per unit area is much higher than that of traditional solid oxide fuel cells.

Therefore, a first aspect of the present invention relates to a method for storing electric energy, said method comprising:

a) Provide a metal-air battery comprising: a.1) a negative electrode containing metal;

a.2) a porous positive air electrode; a.3) an oxygen ion conducting electrolyte; Y

a.4) optionally, a ceramic layer located between the porous positive air electrode and the oxygen ion conducting electrolyte,

b) connect the metal-air battery to an electric power source so that said metal-air battery is recharged electrically,

wherein said method excludes the connection of the metal-air battery to a chemical power source,

and in which the metal-air battery operates at temperatures ranging from about 300 to about 1000 ° C.

A second aspect of the present invention relates to a metal-air battery comprising:

a) a negative electrode containing metal;

b) a porous positive air electrode;

c) an oxygen ion conducting electrolyte; Y

d) optionally, a ceramic layer located between the positive air electrode

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porous and oxygen ion conducting electrolyte,

in which the electrolyte is in contact with the negative electrode containing metal on one side and with the porous positive air electrode on the other side, or when the ceramic layer is present, the solid oxide electrolyte is in contact with the negative electrode containing metal on one side and with the ceramic layer on the other side,

wherein the metal-containing electrode is enclosed in a cover sheath to isolate the electrode from any gas or chemical source;

in which the metal-air battery can only be recharged by electricity and operates at temperatures ranging between approximately 300 and approximately 1000 ° C.

In another aspect, the present invention relates to a module system comprising at least two stacked metal-air batteries as defined above.

Another aspect of the present invention relates to a method for manufacturing the metal-air battery of the present invention, said method comprising:

a) providing a solid oxide electrolyte as defined above;

b) place the porous positive electrode and the metal-containing negative electrode on each side of the solid oxide electrolyte;

c) enclose the negative electrode containing metal in the cover sheath.

Another aspect of the present invention relates to a method for storing electrical energy, said method comprising:

a) provide a metal-air battery as defined above; Y

b) connect the metal-air battery to an electric power source so that said metal-air battery is recharged electrically;

wherein said method excludes the connection of the metal-air battery to a chemical power source,

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and in which the metal-air battery operates at temperatures ranging from about 300 to about 1000 ° C.

Another aspect of the invention relates to the use of the metal-air battery as defined above as an electrical power source for applications in public services as well as a power source for electronic power and automobile applications.

Finally, another aspect of the invention relates to the use of the metal-air battery as defined above as an electric energy storage device for applications in public services as well as for electronic power and automobile applications.

Brief description of the drawings

Figure 1. Illustration of a high-temperature metal-air cell.

Figure 2. Illustration of two options for a flat design of a high-temperature metal-air battery.

Figure 3. Illustration of a tubular design of a high-temperature metal-air battery.

Figure 4. Metal-air battery cell configurations as a function of the material that provides mechanical support: (a) electrolyte; (b) anode; (c) inert substrate.

Figure 5. Examples of interconnections in the flat configuration: a) cells connected in parallel, vertical option; b) cells connected in series, horizontal option.

Figure 6. Examples of interconnections in the tubular configuration: a) cells connected in parallel within a beam; b) several beams connected in a short stack to form a module system.

Figure 7. a) Charge and discharge curves of a tin-air battery at 800 ° C; b) Efficiency curve of the tin-air battery at 800 ° C.

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Figure 8. a) Charge and discharge curves of a tin-air battery using the individual repeating unit of the flat design at 800 ° C (the box corresponds to the enlarged view of the public curves); b) Efficiency curve of the tin-air battery conceptual cell at 800 ° C. Manufacture of the cell under protective gas.

Figure 9. a) Charge and discharge curves of a tin-air battery using the individual repeating unit of the flat design at 800 ° C (the box corresponds to the enlarged view of the public curves); b) Efficiency curve of the tin-air battery conceptual cell at 800 ° C. Manufacture of the air cell.

Detailed description of the invention

Reference will now be made in detail to some specific embodiments of the invention that include the best ways contemplated by the inventors for carrying out the invention. Examples of these specific embodiments are illustrated in the accompanying drawings. Although the invention is described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the invention to the described embodiments. On the contrary, it is intended to cover alternatives, modifications and equivalents since they can be included within the spirit and scope of the invention as defined in the appended claims. In the following description, numerous specific details are explained in order to provide a complete understanding of the present invention. The present invention can be put into practice without some or all of these specific details.

In this specification and in the appended claims, the singular forms "a", "a" and "the" include plural references unless the context clearly dictates otherwise. Unless otherwise defined, all The technical and scientific terms used herein have the same meaning as that commonly understood by a person skilled in the art to which this invention belongs.

In a first aspect, the present invention provides a method for the storage of electrical energy. This method is based on the use of a low-cost metal-air battery, better safety and higher energy density for applications in public and other services, compared to Li-ion and metal-air batteries of the prior art. . In particular, the method of the invention uses a multi-layer system comprising a porous air electrode, designed for high catalytic activity towards oxygen reduction / evolution and mixed electronic and ionic conductivity (or mainly

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electronic) in a wide range of operating temperatures (ie 300-1000 ° C), a metal electrode and an oxygen ion conductor as an electrolyte.

Figure 1 illustrates the concept of the method of the invention using a high temperature metal-air battery. Unlike conventional Li-air batteries in which lithium diffuses through the electrolyte between electrodes, the battery used in the method of the invention carries oxygen ions that diffuse through a solid electrolyte between electrodes. The chemical reactions generated during the electrochemical operation of the metal-air battery are shown below:

Anode: M + xO = or MOx + 2xe "

Catodo: 1 / 2xO2 (g) + 2xe "or xO =

Total: M + 1 / 2xO2 (g) or MOx

More specifically, in the discharge, the oxygen gas is reduced and dissociated into oxygen ions in the cathode. The oxygen ions diffuse through a solid oxide electrolyte from the cathode to the anode and there react with the metal and form a metal oxide in the anode. In the charge, the metal oxide decomposes and oxygen ions are released into the anode which then diffuses to the cathode to form oxygen gas.

Therefore, the electrochemical reaction is reversible and the metal oxides formed during discharge can regenerate into metal when the current is reversed, resulting in a rechargeable system that can be used for many cycles.

The metal-air battery can only be recharged electrically. Therefore, after connection to an electric power source, the metal-air battery is recharged electrically and is ready for use.

The method of the invention only contemplates that the metal-air battery is recharged, electrically and therefore, excludes the connection of the metal-air battery to any other source, such as a chemical source.

A detailed explanation of the components of the metal-air battery is described below.

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Negative electrode containing metal

The negative electrode containing metal constitutes the anode of the battery system and comprises, as the main component, at least one metal, metal alloy or metal-containing compound either in a molten, solid or semi-solid state.

In a particular embodiment of this invention, the metal is selected from alkaline elements, alkaline earth metal elements, elements of group VIB, group VIIB, group VIIIB, group IB, group IIB, group IIIA and VAT group from the periodic table. Preferably, the metal is selected from tin, bismuth, gallium, iron, copper, cobalt, nickel, lead, magnesium, zinc, antimony, indium, sodium, lithium, tungsten, molybdenum, cerium, titanium, manganese, niobium, vanadium and aluminum . More preferably it is tin, bismuth, gallium, zinc, sodium, lithium and aluminum, even more preferably the metal is selected from tin, lithium and zinc.

In addition, in another embodiment of this invention, a mixture of metals can also be used as electrode materials in the metal-air battery system. The metal mixture may be composed of the same elements mentioned above, for example, tin, bismuth, gallium, iron, copper, cobalt, nickel, lead, magnesium, zinc, antimony, indium, sodium, lithium, tungsten, molybdenum, cerium, titanium, manganese, niobium, vanadium and aluminum. The mixture of metals refers to a mixture of homogeneous metals and / or a mixture of non-homogeneous metals, such as a heterogeneous mixture, doped metals and other forms of materials with more than one species of metal such as a mixture of metals or in the form of particles, pressed particles or sintered particles.

Additions can also be used in small fractions of the metals described above to improve the wetting properties and to adjust the melting points and therefore to carefully control the activity of the metals.

In addition, in another embodiment of the invention, metal alloy materials can also be used as electrode materials in the metal-air battery system. Alloy metal materials may be composed of the same elements mentioned above, for example, tin, bismuth, gallium, iron, copper, cobalt, nickel, lead, magnesium, zinc, antimony, indium, sodium, lithium and aluminum.

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In addition, in another embodiment of this invention, the metal-containing electrode may be a combination of metals, mixture of metals, alloy metal materials and compounds containing metals mentioned above.

Preferably, the metal, metal alloy or metal-containing compound is in a molten or liquid state. This allows a better utilization of the metal, resulting in a higher practical energy density. In addition, it reduces mechanical degradation and improves the physical life of the anode due to the self-regeneration function of the liquid.

In another preferred embodiment, the metal, the metal alloy or the metal-containing compound may be in the form of fine metal powders that can be interdispersed with a conductive material to increase the reaction sites and improve fuel utilization.

In another embodiment, the metal, metal alloy or metal-containing compound may be in the form of a solid metal and comprises a molten salt that carries oxygen from the contact surface of the electrolyte to the metal.

In another embodiment, the metal-containing compound may be in the form of a redox pair such as the Na2S / Na2SO4 system.

In another particular embodiment, the metal-containing electrode further comprises a porous matrix that conducts mixed ions or ion-electrons that enhances the active sites of the electrode for the electrochemical reaction, thereby increasing the performance and efficiency of the system. It must be porous in order to allow the metallic fuel to be loaded. Preferably, the porous matrix that conducts mixed ions or electron ions contains interconnected fibers or fine powders.

Therefore, in a preferred embodiment, the metal-containing negative electrode comprises a mixture of:

1) a metal, metal alloy or compound containing metal powder, and

2) a powder or fiber that conducts pure ions or mixed ion-electrons.

In another preferred embodiment, the metal negative electrode comprises a mixture of:

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1) a liquid metal, metal alloy or compound containing metal and

2) a powder or fiber that conducts pure ions or mixed ion-electrons.

Alternatively, the porous matrix that conducts mixed ions or electron ions forms a framework in which the metal, metal alloy or metal-containing compound is contained.

In a preferred embodiment, the porous ion-conducting matrix is composed of a fluorite-related oxygen ion conductor comprising a compound of formula (I):

[(Ai

.x-yA’xA ”y) Os] i-z [(Bi.vB’v) O2] z-d

(Formula I)

in which:

A, A 'and A "are different from each other, and A, A' and A" each independently comprise at least one mono, di or trivalent element selected from yttrium (Y), sodium (Na), scandium (Sc), samarium (Sm), gadolinium (Gd), cerium (Ce), calcium (Ca), magnesium (Mg), aluminum (Al) and bismuth (Bi);

B and B ’are different from each other, and B and B’ each independently comprise a selected cation of zirconium (Zr) and cerium (Ce).

v, x, y and z have values from 0 to 1, with the proviso that x + y is less than or equal to 1;

s has a value that ranges between 0.5 and 1.5; Y

d corresponds to site deviations from stoichiometry.

In formula I, A ’and A” each designate an element that replaces A in a part of the A sites in metal oxides. In addition, B ’replaces B in a part of the B sites in the metal oxide.

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Site A in the material of formula I may include at least one metal element selected from yttrium (Y), scandium (Sc), samarium (Sm), gadolinium (Gd), cerium (Ce), calcium (Ca), magnesium ( Mg), aluminum (Al) and bismuth (Bi). A 'and A ”that substitute A as doping elements, may include an element other than A, for example, at least one element selected from the group consisting of yttrium (Y), sodium (Na), scandium (Sc), samarium (Sm), gadolinium (Gd), cerium (Ce), calcium (Ca), magnesium (Mg), aluminum (Al) and bismuth (Bi).

Site B in the material of formula I may include a metal element selected from zirconium (Zr) and cerium (Ce). B ’, which replaces B as a doping element, can include a different element from B, for example, an element selected from zirconium (Zr) and cerium (Ce).

The compounds of formula (I) may include additions of minor additives, more particularly metal oxides, such as CaO, Na2O, TiO2, Al2O3, Mn2O3, Y2O3, SiO2, Fe2O3 and CeO2.

Examples of fluorite-related oxygen ion conductor include ZrO2 doped with Y2O3, ZrO2 doped with Gd2O3, ZrO2 doped with Sc2O3, Bi2O3, Bi2O3 doped with Y2O3.

The fluorite-related oxygen ion conductor can also be combined with metals having melting points greater than 900 ° C, such as nickel, iron or copper in order to provide a porous matrix that conducts mixed ion-electrons.

Alternatively, the fluorite-related oxygen ion conductor can also be combined or substituted by a transition metal oxide of the perovskite type to provide a porous matrix that conducts mixed ion-electrons. The transition metal oxide of the perovskite type is an oxide that has the same crystalline structure as the mineral CaTiO3, which is normally expressed as ABO3 in which the A and B sites of the metal oxide are each substituted with a different chemical element .

More particularly, a perovskite transition metal oxide has a formula (II):

(Ai.xA’x) i-a (Bi.yB’y) i_bO3-d (Formula II)

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in which:

A and A 'are different from each other and A and A' each comprise at least one element selected from the group consisting of strontium (Sr), yttrium (Y), samarium (Sm), cerium (Ce), bismuth (Bi ), lanthanum (La), gadolinium (Gd), neodymium (Nd), praseodymium (Pr), calcium (Ca), barium (Ba), magnesium (Mg) and lead (Pb);

B and B 'are different from each other, and B and B' each independently comprise at least one element selected from the group consisting of transition metal ions such as titanium (Ti), vanadium (V), manganese (Mn), cobalt (Co), iron (Fe), chromium (Cr), nickel (Ni) or copper (Cu); and gallium (Ga);

x is between 0 and 1; and

and is between 0 and 1,

a, b and d correspond to site deviations with respect to stoichiometry.

In formula II, A 'designates an element that replaces A at a part of the sites A in the metal oxides to produce a n-type material, improving the electrical conductivity of the metal oxide. In addition, B ’replaces B in a part of the B sites in the metal oxide to produce a p-type material, and therefore the B-site atoms vary easily to increase the concentration of oxygen vacancies. The increase in the concentration of oxygen vacancies provides ionic conductivity to a perovskite type material, which increases the transport of oxygen ions to or from the triple phase limit in which an electrochemical reaction occurs. Specific preparation methods can be used to induce site deficiency and therefore to improve electrochemical activity.

Site A in the material of formula II may include at least one metal element selected from strontium (Sr), yttrium (Y), samarium (Sm), cerium (Ce), bismuth (Bi), lanthanum (La), gadolinium ( Gd), neodymium (Nd), praseodymium (Pr), calcium (Ca), barium (Ba), magnesium (Mg) and lead (Pb). A ’, which replaces A as a doping element, can include an electron donor other than A, for example, at least one transition metal. For example, if site A includes Sr, A 'may include at least one element selected from the group consisting of yttrium (Y), samarium (Sm), lanthanum (La), gadolinium (Gd), neodymium (Nd), praseodymium (Pr), calcium (Ca), magnesium (Mg) and barium (Ba).

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Site B in the material of formula II may include at least one metal element selected from titanium (Ti), manganese, (Mn), cobalt (Co), iron (Fe), nickel (Ni), chromium (Cr), vanadium (V), gallium (Ga) and copper (Cu). B ', which replaces B as a doping element, may include an electron acceptor other than B, for example, at least one transition metal or at least one element selected from the group consisting of titanium (Ti), manganese (Mn) , cobalt (Co), iron (Fe), chromium (Cr), gallium (Ga), ticket (Ni) and vanadium (V).

Examples of these perovskite transition metal oxides are (La, Sr) TiO3, (Y, Sr) TiOs, (LaSr) CrO3, (La, Sr) (Cr, V) O3, (La, Sr) (Ga , Mn) O3, (La, Sr, Ca) (Mn, Cr) O3,

(La, Sr) (Ti, Mn) O3.

An example of a material that conducts mixed ion-electrons is a composite material of the perovskite-fluorite type such as (SrLa) TiO3-Ce (La) O2-d.

The metal-containing electrode or anode of the metal-air battery system usually does not need any catalyst because the electrochemical reaction is carried out on the surface of the metal itself.

In a particular embodiment, the metal electrode is enclosed in a cover sheath. By the expression "cover sheath", a sheath designed to isolate the metal-containing electrode (anode) from any gas or chemical source should be understood. However, this sheath must allow the contact of the metal-containing electrode with the conductive electrolyte of Oxygen ions Therefore, said cover sheath is provided with an open side through which the sheath is fixed or sealed to the electrolyte, allowing the contact of said electrolyte with the metal-containing electrode.

The cover sheath also acts as a protective cover sheath to protect said metal-containing electrode from reactions that induce its degradation or deactivation. For example, this sheath can act as a gas-tight cover of the metal electrode, in order to minimize exposure to any gas, and in particular to prevent its oxidation in contact with the atmosphere. This case can also act as a chamber separator and current collector and / or interconnection system.

This case is normally composed of an electronically conductive material so that it can form an electric cable of the battery. The cover can be composed

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for any metal that is not reactive with the other system components. With respect to this, the sheath may be composed of an alloy metal, such as ferritic steels with or without nickel, for example those commonly known as Crofer type materials. In another embodiment, the sheath may be composed of any ceramic conductive material, not reactive with the other components.

In addition, the electronically conductive material may be passivated or coated to prevent chromium poisoning of the air electrode or side reactions that induce degradation.

In particular, the electronically conductive material is treated (passive) or preferably coated to produce a protective layer that prevents the reaction of the metal sheath and electrode during the processing and operation of the metal-air battery system. The protective layer includes spinel type oxides, for example spinels containing manganese and cobalt or manganese, spinals containing cobalt and iron. Other examples of protective layers include perovskite type oxides of formula II, such as perovskite type oxides containing La-Sr-Fe or La-Sr-Fe-Cu. Additional examples include fluorite type materials such as CeO2, and other oxides such as Y2O3 related materials. These protective layers can be generated "in situ" or can be deposited on top of the electronically conductive material by conventional methods such as reactive sintering, chemical vapor deposition, cathode bombardment, spraying, immersion coating, screen printing and others.

In another particular embodiment, the sheath is composed of an electrically insulating material, in which case a separate current collector can be arranged therein.

The metal-sheath electrode assembly may be electrolyte sealed with a combination of one or more sealing parts such as glass seals, metal based seals and ceramic parts such as alumina or mica type felts, to provide a sheath of Cover as tight as possible.

In a preferred embodiment, said cover sheath is a gas tight cover sheath.

Porous positive air electrode

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The porous positive air electrode constitutes the cathode of the metal-air battery system used in the method of the invention. It comprises a thin porous layer composed of electronically and ionically conductive materials or composites. It must be porous in order to allow oxygen molecules to reach the electrode / electrolyte contact surface.

In a preferred embodiment of the invention, the porous layer is composed of a transition metal oxide of the perovskite type or perovskite composites with fluorite-related oxygen ion conductors, such as those defined above for the metal electrode.

More preferably, the transition metal oxide of the perovskite type, or ABO3, has a formula (IN):

(Lni_xMx) i-a (Bi_yB’y) i_bO3-d (Formula III)

in which:

Ln is a lanthanide cation selected from lanthanum (La), praseodymium (Pr), neodymium (Nd), samarium (Sm) and gadolinium (Gd);

M is at least one alkaline earth cation selected from calcium (Ca), strontium (Sr) and barium (Ba);

B and B 'are different from each other, and B and B' each independently comprise at least one element selected from the group consisting of cobalt (Co), iron (Fe), chromium (Cr), copper (Cu) and manganese ( Mn) .;

x e y are the combination ratios of site A and site B cations ranging from 0

and i; Y

a, b and d correspond to atomic site deviations from stoichiometry.

Examples of these perovskite transition metal oxides are (LaSr) CoO3, (La, Sr, Ca) (Mn, Cr) O3 and (La, Sr) (Fe, Co) O3.

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The fluorite-related oxygen ion conductor typically comprises a compound of formula (I) or mixed solutions of two or more oxide systems as shown in formula (I):

[(Ai

-x-yA'xA ”y) Os] i-z [(Bi-vB'v) O2]

Jz-d

(Formula I)

in which

A, A 'and A ”are different from each other, and A, A' and A” each independently comprise at least one mono, di or trivalent element selected from yttrium (Y), sodium (Na), scandium (Sc), samarium (Sm), gadolinium (Gd), cerium (Ce), calcium (Ca), magnesium (Mg), aluminum (Al) and bismuth (Bi);

B and B 'are different from each other, and B and B' each independently comprise a cation selected from zirconium (Zr) and cerium (Ce).

v, x, y and z have values from 0 to 1, with the proviso that x + y is less than or equal to 1;

s has a value that ranges between 0.5 and 1.5;

d corresponds to site deviations from stoichiometry.

The compounds of formula (I) may include additions of minor additives, more particularly metal oxides, such as CaO, Na2O, TiO2, Al2O3, Y2O3, SiO2, Fe2O3 and CeO2.

The ceramic materials used to make the cathode do not become electrically and ionically active until they reach high temperature and, as a consequence, the metal-air battery of the invention has to operate at temperatures ranging between 300 and 1000 ° C.

In a particular embodiment, a barrier in the form of a ceramic layer is inserted between the cathode and the electrolyte in order to prevent the chemical reaction between cathode and electrolyte materials and to enhance the electrochemical yields. The intermediate barrier layer is normally composed of cerium-based fluorite-related oxides as described in formula (I).

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Although it is not essential to carry out the present invention due to the high temperatures at which the metal-air battery operates, the cathode may include a catalytic material that facilitates the reduction of oxygen. The catalyst can either be physically mixed with the material that forms the porous air electrode or chemically bonded thereto. Any metal that can be used as a catalyst material for an electrode can be used herein. In one embodiment, the metal includes, but is not limited to, a noble metal, a metal oxide, a metal alloy, an intermetallic compound or mixtures of the aforementioned metals. Noble metals include silver, platinum, palladium, iridium, osmium, rhodium and ruthenium. However, mixtures or alloys thereof can also be used. Such a catalyst can be used either individually or in combination, although other catalytic materials can also be incorporated.

Additionally, the porous air electrode can also be enclosed in a sheath that houses the cathode and an associated electrical cable. This case may also include electrode holders, interconnection structures and / or current collection and the like. It can also include at least one opening to allow the passage of ambient air to the cathode.

In the operation of the metal-air battery, the air passes to the cathode. In the cathode, oxygen is reduced to form oxygen ions, and in the process it consumes electrons. The oxygen ions diffuse through the solid oxide electrolyte and react with the anode metal and form a metal oxide, thus generating electrons that flow to the cathode through an external circuit in communication with the anode sheath and the cable of the anode. cathode. In the operation of the battery, the anode metal is consumed and converted into a metal oxide. When all the metal is consumed, the cell stops working and must be recharged electrically to work again.

Solid oxide electrolyte

The solid oxide electrolyte is a membrane disposed between the metal electrode and the porous air electrode. Once the molecular oxygen has been converted to oxygen ions in the air cathode, said oxygen ions migrate through the electrolyte to the metal electrode (anode). In order for such migration to occur, the electrolyte must have a high ionic conductivity. However, its electronic conductivity must be kept as low as possible to prevent losses due to leakage currents.

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The electrolyte must also be gas tight to prevent short circuits of reactive species through it and it is desirable that it be as thin as possible to minimize resistive losses in the system. It must also be chemically, thermally and structurally stable over a wide temperature range.

The electrolyte must comprise at least one material selected from the group consisting of zirconium oxide, cerium oxide and a perovskite group consisting of lanthanum doped gallate (LSGM), or any other material commonly used as SOFC electrolyte materials. The solid oxide electrolyte can also be a fluoride-related oxygen ion conductor, such as yttria stabilized zirconia ("YSZ"), scandia stabilized zirconia ("ScSZ"), ceria doped with samaria ("SDC"), ceria doped with gadolinia ("GDC"), or the like.

The fluorite-related oxygen ion conductor typically comprises a compound of formula (I):

[(Ai-x-yA’xA ”y) Os] i-z [(Bi-vB’v) O2] z-d (formula I)

in which

A, A 'and A "are different from each other, and A, A' and A" each independently comprise at least one mono, di or trivalent element selected from yttrium (Y), sodium (Na), scandium (Sc), samarium (Sm), gadolinium (Gd), cerium (Ce), calcium (Ca), magnesium (Mg), aluminum (Al) and bismuth (Bi);

B and B 'are different from each other, and B and B' each independently comprise a selected cation of zirconium (Zr) and cerium (Ce);

v, x, y and z have values from 0 to 1, with the proviso that x + y is less than or equal to 1;

s has a value that ranges between 0.5 and 1.5;

d corresponds to site deviations from stoichiometry.

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The compounds of formula (I) may include minor additions of additives, more particularly metal oxides, such as CaO, Na2O, TiO2, Al2O3, Y2O3, SiO2, Fe2O3 and CeO2.

Examples of materials that conduct ions that can also be used as an electrolyte for the metal-air battery system of the invention are:

(BiOi, 5) x (YOi, 5) i-x; (Ba, Th) xGdi-xOi, 5; (LaxSri-x) (GayMgi-y) O3; (CeO2) x (GdOi, 5) i-x;

(ZrO2) x (ScOi, 5) i-x; (ZrO2) x (YOi, 5) i-x, (CaO) i-x (ZrO2) x; LaCaAlO2, in which x is a value from 0 to i, or any other ionic conductor of the fluorite type as described above.

The electrolyte is prepared by common methods known to those skilled in the art, particularly by following procedures such as those used when solid oxide fuel cells are manufactured.

A further aspect of the invention relates to a metal-air battery comprising:

a) a negative electrode containing metal;

b) a porous positive air electrode;

c) an oxygen ion conducting electrolyte; Y

d) optionally, a ceramic layer located between the porous positive air electrode and the oxygen ion conducting electrolyte,

in which the electrolyte is in contact with the negative electrode containing metal on one side and with the porous positive air electrode on the other side, or when the ceramic layer is present, the solid oxide electrolyte is in contact with the negative electrode containing metal on one side and with the ceramic layer on the other side,

wherein the metal-containing electrode is enclosed in a cover sheath to isolate the electrode from any gas or chemical source;

in which the metal-air battery can only be recharged by electricity and operates at temperatures ranging between approximately 300 and approximately 1000 ° C.

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The components of the metal-air battery of the invention, that is, the negative electrode containing metal and its sealed cover sheath, the porous positive air electrode, the oxygen ion conducting electrolyte; and the optional ceramic layer located between the porous positive air electrode and the oxygen ion conducting electrolyte are those as mentioned hereinbefore.

The metal-air battery of the invention is characterized in that the metal-containing electrode (anode) is enclosed in a cover sheath that allows contact of the metal-containing electrode with the oxygen ion conducting electrolyte. As mentioned earlier, the cover sheath is designed to isolate the metal-containing electrode from any gas or chemical source so that battery operation can only occur through electrochemical charge and discharge. The cover sheath that encloses the metal-containing electrode is efficient enough to guarantee the culinary efficiency of the battery system.

Preferably, the cover sheath is a gas-tight cover sheath that allows to produce a culinary efficiency of 1.

Accordingly, the metal-air battery of the invention functions as an electrical energy storage device and not as an energy conversion device and has a high potential storage capacity since no fuel tank or gas supply is used for recharge the battery.

The metal-air battery system of the invention may include other additional components such as intermediate layers, contact layers, buffers and protective layers. For example, when bismuth-based materials are used as solid oxide electrolyte, an intermediate layer must be placed between the metal-containing electrode and the electrolyte in order to avoid reactions between both components of the metal-air battery system.

In a particular embodiment of the invention, the electrode containing metal enclosed in the cover sheath, the electrolyte and the cathode are incorporated into a battery case. This battery case has an oxygen supply hole in the vicinity of the cathode to supply oxygen to the cathode. It also includes electrode terminals that extend from the inside to the outside of the battery case and that are respectively

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connected to the cathode and anode to allow current to flow from one electrode to the other.

This battery case may also be provided with a reducing / inert protective gas, such as argon or nitrogen, in order to prevent the penetration of oxygen into the cover case that encloses the metal-containing electrode.

In addition, the battery case can be designed in such a way that it also includes gas distribution for air electrode, to ensure the collection of current from the air electrode with sufficient air flow distribution to enhance the electrochemical reaction.

As those skilled in the art will appreciate, the battery system of the present invention can be implemented in a variety of configurations and designs. It can adopt a flat design (figure 2) in which a flat cathode structure (3), electrolyte (1) and anode (2) is manufactured to form a metal-air cell or battery. Figure 3 illustrates a tubular design in which metal fuels are contained within a tubular assembly to form a cell.

It should be noted that in Figures 2 to 6 of the present invention the element (1) corresponds to the electrolyte, the element (2) to the anode, the element (3) to the cathode, the element (4) to the cover sheath, the element (5) to a current collector and element (6) to a sealing system.

Multiple metal-air cells or batteries can be stacked to form a stack or module system. Therefore, another aspect of the present invention relates to a module system comprising at least two stacked metal-air batteries as defined above. This system comprises metal-air batteries that repeat units stacked in a module with variable output power depending on the final application.

The repeating units of the metal-air battery are connected by means of designs that minimize ohmic losses and guarantee sufficient air flow to the air cathode.

The materials used to interconnect the repeating units of the metal-air battery can be metallic or ceramic, with the coating / treatments required to ensure compatibility with other components.

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In a particular embodiment, the cover sheath designed to insulate the metal electrode and to prevent it from being exposed to any gas acts as a current collector and / or interconnector. This case comprises a secondary part connected to the air electrode, which acts as a current collector and / or gas distribution system and / or interconnector between cells.

The module system can be sealed by means of ceramic and metal pastes and / or sealing felts that support the operating conditions.

In a particular embodiment, the module system has a flat or tubular configuration. In the flat configuration (figure 4), the flat electrochemical device can be mechanically supported by the electrolyte (figure 4a) or by one of the electrodes (figure 4b) or by an inert substrate material (8) of a nature either metallic or ceramic (figure 4c). In the tubular configuration, the tubular electrochemical device can be mechanically supported by the electrolyte or by one of the electrodes or an inert substrate material with one or both ends open.

The final design will depend on the intended application.

The repeating units of the metal-air battery are electrically connected to each other. The electrochemical connections between individual repeating units to form the stacking or module system can be either in series or in parallel.

In a particular embodiment, each metal-air battery repeat unit, in either flat or tubular configuration, is connected in parallel with the adjacent metal-air battery repeat unit to form a beam. The set of beams is further connected in series to accumulate the specific power specifications.

In another particular embodiment, each metal-air battery repeating unit, in either flat or tubular configuration, is connected in series with the adjacent metal-air battery repeating unit to form a beam. The set of beams is additionally connected in parallel or in series to accumulate the specific power specifications.

Figure 5 illustrates examples of flat individual repeating units stacked in bundles

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with internal connections (7) either in series or in parallel. In more detail, Figure 5a shows flat cells connected in parallel through the conductive sheath of the anode. The parallel connection of the cathodes can be carried out by means of a conductive plate that can be perforated, corrugated or designed and mechanized in such a way that it allows electrical conduction and sufficient gas flow. This example can be placed vertically to ensure contact of the anode with the electrolyte and metal sheath. A beam with the following can be connected additionally either in parallel or in series according to the system specifications. Figure 5b shows a modification of the flat configuration in which an additional conductive part that acts as an interconnection of the cathode of a cell with the anode of the next cell in serial beam connection is introduced. This additional part may be perforated in certain regions, corrugated or designed and machined in such a way that it allows electrical conduction and sufficient gas flow. An additional beam can be connected to the next one either in parallel or in series according to system specifications.

Figure 6a shows an example of a tubular system beam with internal connections between cells, as a preferred option, in parallel. Then beams are connected either in series or in series and parallel combinations in order to accumulate the required specifications of the system module (Figure 6b).

Another aspect of the present invention relates to a method for manufacturing the metal-air battery of the present invention. Said method comprises:

a) providing a solid oxide electrolyte as defined above;

b) place the porous positive electrode and the metal-containing negative electrode on each side of the solid oxide electrolyte;

c) enclose the negative metal electrode in the cover sheath.

It should be noted that the order of stages b) and c) is not particularly limited. However, in a preferred embodiment the negative electrode containing metal is deposited and processed on the electrolyte before encasing the electrode in the cover sheath.

The structure obtained following steps a) to c) can be additionally installed in a battery case and sealed tightly to produce the metal-air battery.

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In a preferred embodiment, this battery case is provided with a reducing / inert protective gas, such as argon or nitrogen, in order to prevent the penetration of oxygen into the cover case that encloses the metal-containing electrode.

In a particular embodiment, when a metal-air battery system with flat design is manufactured, the solid electrolyte can be prepared from powder formulations by laminar casting, slip casting, laminating calendering and the like. Subsequently, the electrolyte is sintered at high temperature to achieve full density before depositing the electrodes.

In another particular embodiment, when a metal-air battery system with tubular design is manufactured, the solid electrolyte can be prepared by extrusion, slip casting, isostatic pressure and the like. Subsequently, the electrolyte is sintered at high temperature to achieve full density before depositing the electrodes.

Preferably, the solid electrolyte is made thick and dense in order to act as a substrate or support for the battery system.

In another particular embodiment, step b) of the process of the invention is carried out by depositing and processing in powder, the porous positive electrode and the metal-containing negative electrode on each side of the solid oxide electrolyte.

The deposition of the electrodes on each side of the electrolyte involves the prior preparation of suspension formulations comprising powder materials constituting said electrodes. Said suspension formulations can be prepared by grinding with powders of zircona with water-based binders or based on suitable organic compounds and additives to achieve a suitable rheology that provides microstructures with objectives in terms of thickness, porosity and permeation. The ceramic powder material used to make the electrodes can be ground, calcined and screened before preparing the suspensions for electrode deposition.

Once the suspension formulations have been prepared, the deposition of the electrodes on each side of the electrolyte is carried out by means of laminar casting, laminar calendering, immersion coating, pulverization, screen printing, chemical deposition in vapor phase, physical deposition in vapor phase , cathode bombardment, electrophoretic deposition,

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reactive sintering and the like.

Once the electrodes are deposited on each side of the solid oxide electrolyte, they are subjected to a powder processing in order to obtain a solid electrode.

In the powder processing stage, the atmospheres and temperatures are adjusted as a function of the powders, the deposition technique used and the geometry or configuration of the system, but include oxidizing, inert or reducing atmospheres.

Once the porous positive electrode and the metal-containing negative electrode on each side of the solid oxide electrolyte have been placed, the metal-containing electrode is enclosed in a cover sheath. This cover sheath is fixed or sealed to the electrolyte through its open side by means of sealing agents, such as glass seals, metal based seals and ceramic pieces such as alumina or mica type felts, to provide a sheath Cover as tight as possible.

This way of placing the electrodes on each side of the electrolyte is particularly useful when manufacturing a metal-air battery system with flat design.

However, as an alternative, step b) can be carried out by first depositing and processing the porous positive electrode on powder on one side of the solid oxide electrolyte following a procedure as described above. Subsequently, the cover sheath is fixed or sealed to the previously obtained positive electrolyte / cathode block, and then the previously obtained negative metal electrode, preferably as a solid electrode, is placed inside the cover sheath and coated with a sealing cap .

When a tubular design is desired, step b) is preferably carried out by first depositing and processing the porous positive electrode on powder on one side of the solid oxide electrolyte following a procedure as described above. Subsequently, the previously obtained negative metal electrode, preferably as a solid electrode, is placed inside a tube that acts as a cover sheath and then fixed on the free side of the solid oxide electrolyte.

Due to the excellent properties of the metal-air battery of the present invention, in particular its high energy density and long cycle life, it can be used as a source of

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power supply of small devices as well as power supply for automobile applications, such as electric vehicles and horrid cars. In addition, it can also be used as an energy storage device for applications in public services as well as for power electronic applications and in automobiles.

The present invention will now be described in detail by way of examples that serve to illustrate the construction and tests of illustrative embodiments. However, it will be understood that the present invention is not limited at all to the examples set forth below.

Example 1

Laboratory scale cells using molten tin and other metal electrodes.

A zircona electrolyte doped with yttrium (YSZ) was used to deposit a perovskite or perovskite cathode material containing La-Sr-Fe or La-Sr-Co and baked in air at a temperature between 800 and 1200 ° C. Pt was baked together for the collection of current in laboratory scale tests. An intermediate layer of ceria doped with samarium or gadolinium or yttrium (SDC, GDC, YDC) can be inserted between cathode and electrolyte layers during cathode system processing. The electrolyte-cathode system was then sealed using a ceramic-based sealant paste in an alumina or quartz tube. The solid tin metal anode material was placed inside the tube on the free side of the electrolyte. The metal current collection system, welded to Pt wires before the passivation / coating, was then placed inside the tube avoiding contact with the solid anode material. Reducing / inert protective gas was introduced on the side of the anode and the system was heated to operating temperature. Once the anode material was in the molten state, the current collector was introduced into the molten anode and the unloading / loading operation was started with inert gas or in a closed realization.

The discharge and load profiles at 800 ° C were tested. As shown in Figure 7, the system is electrochemically reversible.

At the laboratory cell level, other materials such as solid metal anode materials have been tested under the conditions described above. The following table provides initial values of capacities, measured throughout an area

Two-dimensional active of approximately 2 cm2 for Sn, Sn-W, Bi and Sn-Mn.

 Anode material

 Capacity (mAh)

 Sn

 30

 W

 319

 Bi

 168.8

 Sn-Mn

 16

 Sn-Ti

 30

Example 2

5

Individual repeating unit cells were constructed using molten tin as a metal electrode using the flat system design (Figure 2a).

A zircona electrolyte doped with yttrium (YSZ) was used to deposit a material of 10 cathode of perovskite or perovskite containing La-Sr-Fe or La-Sr-Co and baked in air at a temperature between 800 and 1200 ° C. Pt was baked together for the collection of current in laboratory scale tests. An intermediate layer of ceria doped with samarium or gadolinium or yttrium (SDC, GDC, YDC) can be inserted between cathode and electrolyte layers during cathode system processing. The electrolyte-cathode system is then sealed using a glass sealant tape to an electronically conductive material, which is to be used as a container for the solid anode metal. The first sealing phase was carried out in air. The solid anode was placed in the container and covered with a metal lid sealed with glass sealing tape. The second phase is baked under argon. The system is a closed realization that prevents gas leakage. In addition, cell 20 was placed under inert protective gas, ensuring that no oxygen penetrated the anode side. The current collection was carried out directly by means of the anode metal container that was a conductive material, in which Pt wires were welded before passivation / coating of the metal container. Reducing / inert protective gas was flowed to the closed system and then heated to operating temperature. The discharge and load profiles were tested at 800 ° C. As shown in Figure 8, the system is electrochemically reversible, obtaining more than 1300 cycles with 100% efficiency.

Example 3

Individual repeating unit cells were constructed using molten tin as a metal electrode using the flat system design (Figure 2a). V ^ a of cost effective alternative processing.

A zircona electrolyte doped with yttrium (YSZ) was used to deposit a perovskite or perovskite cathode material containing La-Sr-Fe or La-Sr-Co and baked in air at a temperature between 800 and 1200 ° C. Pt was baked together for the collection of current in laboratory scale tests. An intermediate layer of ceria 10 doped with samarium or gadolinium or yttrium (SDC, GDC, YDC) can be inserted between cathode and electrolyte layers during cathode system processing. The electrolyte-cathode system is then sealed using a glass sealing tape to an electronically conductive material, which is to be used as a container for the solid anode metal. The first sealing phase was carried out in air. The solid anode was placed in the container and covered with a metal lid sealed with glass sealing tape. The second phase was also processed in air. The system is a tight closed realization, in which no inert protective gas is needed. The current collection was carried out directly by means of the anode container which was a conductive material, in which Pt wires were welded before the passivation / coating of the metal cover sheath. The system was heated to 20 operating temperature. The discharge and load profiles at 800 ° C were tested. As shown in Figure 9, the system is electrochemically reversible, obtaining more than 500 cycles with 100% efficiency. This alternative includes full electric recharging at 800 ° C as initial cell conditioning.

Claims (6)

5 10 fifteen twenty 25 30 35 Method for the storage of electrical energy, said method comprising: a) provide a metal-air battery comprising: a.1) a negative electrode containing metal (2); a.2) a porous positive air electrode (3); a.3) an oxygen ion conducting electrolyte (1); Y a.4) optionally, a ceramic layer located between the porous positive air electrode (3) and the oxygen ion conducting electrolyte (1), b) connect the metal-air battery to an electric power source so that said metal-air battery is recharged electrically, wherein the negative electrode containing metal (2) is enclosed in a cover sheath (4) to isolate the electrode from any gas or chemical source, and in which said cover sheath (4) is provided with an open side through which the cover sheath is fixed or sealed to the electrolyte (1), allowing the contact of said electrolyte (1) with the metal-containing electrode (2), wherein said method excludes the connection of the metal-air battery to a chemical energy source and in which the metal-air battery operates at temperatures ranging from about 300 to about 1000 ° C. Metal-air battery comprising: a) a negative electrode containing metal (2); b) a porous positive air electrode (3); 5 10 fifteen twenty 25 30 35 c) an oxygen ion conducting electrolyte (1); Y d) optionally, a ceramic layer located between the porous positive air electrode (3) and the oxygen ion conducting electrolyte (1), wherein the electrolyte (1) is in contact with the negative electrode containing metal (2) on one side and with the porous positive air electrode (3) on the other side, or when the ceramic layer is present, the solid oxide electrolyte (1) is in contact with the negative electrode containing metal (2) on one side and with the ceramic layer on the other side, in which the electrode containing metal (2) is enclosed in a cover sheath (4) to isolate the electrode from any gas or any chemical source, and in which the cover sheath (4) is provided with an open side through which the cover sheath (4) is fixed or sealed to the electrolyte (1), allowing said electrolyte (1) to contact the metal-containing electrode (2), said cover sheath (4) being made of an electronically conductive material selected from a metal or ceramic material, which does not react with the other components of the battery, said conductive material being optionally passivated or coated; Y in which the metal-air battery can only be recharged by electricity and operates at temperatures ranging between approximately 300 and approximately 1000 ° C. Metal-air battery according to claim 2, wherein the negative metal-containing electrode (2) comprises at least one metal, a metal alloy or a metal-containing compound, wherein the metal, the metal alloy or the compound Containing metal is in a molten, solid or semi-solid state. Metal-air battery according to any of claims 2 or 3, wherein the metal is selected from tin, bismuth, gallium, iron, copper, cobalt, nickel, lead, magnesium, zinc, antimony, indium, sodium, lithium and aluminum. Metal-air battery according to any of claims 2 to 4, wherein the metal, the metal alloy or the metal-containing compound is in a molten or powder form. 5 10 fifteen twenty 25 30 35 Metal-air battery according to any of claims 2 to 5, wherein the metal-containing electrode (2) further comprises a porous matrix that conducts mixed ions or ion-electrons. Metal-air battery according to claim 6, wherein the negative electrode containing metal (2) comprises: a mix of: 1) a metal, metal alloy or compound containing metal powder, and 2) a fiber or powder that conducts mixed ions or electron ions; or a mix of: 1) a liquid metal, metal alloy or compound containing metal and 2) a fiber or powder that conducts mixed ions or ion-electrons. Metal-air battery according to any of claims 6 to 7, wherein the porous matrix that conducts ions comprises a fluorite-related oxygen ion conductor comprising a compound of formula (I): [(Ai.x-yA’xA ”y) Os] i-z [(Bi-vB’v) O2] z-d (Formula I) in which A, A 'and A "are different from each other, and A, A' and A" each independently comprise at least one mono, di or trivalent element selected from yttrium (Y), sodium (Na), scandium (Sc), samarium (Sm), gadolinium (Gd), cerium (Ce), calcium (Ca), magnesium (Mg), aluminum (Al) and bismuth (Bi); B and B ’are different from each other, and B and B’ each independently comprise a cation 5 10 fifteen twenty 25 30 35 selected from zirconium (Zr) and cerium (Ce); v, x, y and z have values from 0 to 1, with the proviso that x + y is less than or equal to 1; s has a value that ranges between 0.5 and 1.5; Y d corresponds to site deviations from stoichiometry. Metal-air battery according to any of claims 6 to 8, wherein the porous matrix conducting mixed ion-electrons comprises a fluorite-related oxygen ion conductor according to claim 8 and / or - a perovskite transition metal oxide of the formula (II): in which: (Al-xA’x) l-a (Bl_yB’y) l_bO3-d (Formula II) A and A 'are different from each other and A and A' are each independently at least one element selected from the group consisting of strontium (Sr), yttrium (Y), samarium (Sm), cerium (Ce), bismuth (Bi ), lanthanum (La), gadolinium (Gd), neodymium (Nd), praseodymium (Pr), calcium (Ca), barium (Ba), magnesium (Mg) and lead (Pb); B and B ’are different from each other and, B and B’ include at least one element selected from the group consisting of transition metal ions and gallium (Ga); x has values from 0 to 1; and has values from 0 to 1; a, b and d correspond to site deviations with respect to stoichiometry. Metal-air battery according to any of claims 2 to 9, wherein the porous positive air electrode (3) comprises a mixed oxygen and electron ion conductor. 5 10 fifteen twenty 25 30 35 Metal-air battery according to claim 10, wherein the mixed oxygen electron and ion conductor comprised in the positive porous air electrode is composed of: - a perovskite transition metal oxide of formula (IN): (Lni_xMx) i-a (Bi_yB’y) i_bO3-d (Formula III) in which: Ln is a lanthanide cation selected from lanthanum (La), praseodymium (Pr), neodymium (Nd), samarium (Sm) and gadolinium (Gd); M is at least one alkaline earth cation selected from calcium (Ca), strontium (Sr) and barium (Ba); B and B ’are different from each other, and B and B’ include at least one element selected from cobalt (Co), iron (Fe), chromium (Cr), copper (Cu) and manganese (Mn); x e y are the proportions of the combination of cations of site A and site B ranging between 0 and 1; Y a, b and d correspond to atomic site deviations from stoichiometry. or a material composed of a perovskite transition metal oxide as defined above with a fluorite-related oxygen ion conductor of formula (I): [(Ai -x-yA’xA ”y) Os] l-z [(Bl-vB’v) O2] Jz-d (Formula I) in which A, A ’and A” are different from each other, and A, A ’and A” each comprise independent 5 10 fifteen twenty 25 30 35 minus a mono, di or trivalent element selected from yttrium (Y), sodium (Na), scandium (Sc), samarium (Sm), gadolinium (Gd), cerium (Ce), calcium (Ca), magnesium (Mg), aluminum (Al) and bismuth (Bi); B and B 'are different from each other, and B and B' each independently comprise a selected cation of zirconium (Zr) and cerium (Ce); v, x, y and z have values from 0 to 1, with the proviso that x + y is less than or equal to 1; s has a value that ranges between 0.5 and 1.5; d corresponds to site deviations from stoichiometry. Metal-air battery according to any one of claims 2 to 11, wherein the oxygen ion conducting electrolyte (1) is a fluorite-related oxygen ion conductor of formula (I): [(A1-x-yA’xA ”y) Os] 1-z [(B1-vB’v) O2] z-d (Formula I) in which A, A 'and A "are different from each other, and A, A' and A" each independently comprise at least one mono, di or trivalent element selected from yttrium (Y), sodium (Na), scandium (Sc), samarium (Sm), gadolinium (Gd), cerium (Ce), calcium (Ca), magnesium (Mg), aluminum (Al) and bismuth (Bi); B and B ’are different from each other, and B and B’ each independently comprise a selected cation of zirconium (Zr) and cerium (Ce). v, x, y and z have values from 0 to 1, with the proviso that x + y is less than or equal to 1; s has a value that ranges between 0.5 and 1.5; d corresponds to site deviations from stoichiometry. 13. Module system comprising at least two stacked metal-air batteries according to any one of claims 2 to 12. 5. Metal-air battery according to any of claims 2 to 12 or system of modules according to claim 13, which is designed flat or tubular. 15. Method for manufacturing the metal-air battery system according to any one of claims 2 to 12, said method comprising: 10 - providing an oxygen ion conducting electrolyte (1) as defined above; - place the porous positive air electrode (3) and the negative electrode that 15 contains metal (2) on each side of the solid oxide electrolyte; - enclose the negative metal electrode in the waterproof cover (4). 16. Method for storing electrical energy, said method comprising: twenty a) providing a metal-air battery according to claims 2 to 12; b) connect the metal-air battery to an electric power source so that said metal-air battery is recharged electrically, 25 wherein said method excludes the connection of the metal-air battery to a chemical energy source. 17. Use of the metal-air battery according to any of claims 2 to 12 or 30 module system according to claim 13, as a power source for applications in public services as well as power supply for power electronic applications and in automobiles. 18. Use of the metal-air battery according to any of claims 2 to 12 or 35 module system according to claim 13, as storage device of energy for applications in public services as well as for applications Power and car electronics.