KR102196364B1 - Electrolyte Solution, preparation method thereof and magnesium battery comprising the electrolyte solution - Google Patents

Abstract

An electrolyte containing a cyclic or chain bissilylamide magnesium salt containing two Si-N-Si cores and an N-Mg-N bond, a method of manufacturing the same, and a magnesium battery comprising the electrolyte do.

Description

Electrolyte solution, preparation method thereof and magnesium battery comprising the electrolyte solution

It relates to an electrolytic solution, a method of manufacturing the same, and a magnesium battery including the electrolytic solution.

Recently, interest in materials for batteries for power storage is increasing.

Magnesium batteries are being actively studied because they are eco-friendly, have excellent price competitiveness, and have high energy storage characteristics compared to conventional lithium batteries, lead 　 storage batteries, nickel-cadmium batteries, nickel-hydrogen batteries and nickel-zinc batteries.

In a typical magnesium battery, a positive electrode containing a metal sulfide-based active material in a bulk form such as Mo ₃ S ₄ , a negative electrode containing a magnesium-based active material such as magnesium or an alloy thereof, and a magnesium salt are dissolved in an organic solvent. A prepared electrolyte solution is provided.

Since the electrolyte is in contact with the material constituting the anode and the cathode, it must maintain chemical reactivity, but most of the electrolyte can stop the electrochemical reaction by forming a film on the cathode.

Therefore, there is a need for an electrolyte containing a new magnesium salt that is electrochemically stable and can improve efficiency by increasing the reversibility of deposition/elution of magnesium.

One aspect is to provide an electrolyte that is electrochemically stable and can improve efficiency by increasing the reversibility of deposition/elution of magnesium.

Another aspect is to provide a method of manufacturing an electrolyte solution capable of industrial application in large quantities.

Another aspect is to provide a magnesium battery including the electrolyte.

According to one aspect,

There is provided an electrolyte solution containing a cyclic or chain bissilylamide magnesium salt containing two Si-N-Si cores and an N-Mg-N bond.

According to the other side,

Non-aqueous organic solvents;

A cyclic or chain bissilylamide magnesium salt comprising two Si-N-Si cores and an N-Mg-N bond; And

It provides an electrolyte solution containing; Lewis acid.

According to another aspect,

An electrolyte solution of a cyclic or chain bissilylamide magnesium salt containing two Si-N-Si cores and an N-Mg-N bond by adding a polar organic solvent to a cyclic or chain silylamide halide-containing magnesium salt. There is provided a method of manufacturing an electrolyte solution including a manufacturing step.

According to another aspect,

A positive electrode including a positive electrode active material for storing and releasing magnesium ions;

A negative electrode including a negative electrode active material for storing and releasing magnesium ions; And

There is provided a magnesium battery including the above-described electrolyte impregnated between the positive electrode and the negative electrode.

The electrolyte according to an aspect and a magnesium battery including the same are electrochemically stable, including a bissilylamide magnesium salt, and may have an oxidation potential of 3.0 (vs. Mg/Mg ^{2 +} ) or higher, and the deposition/elution of magnesium Efficiency can be improved by increasing reversibility. In addition, since the bissilylamide magnesium salt does not contain halogen, the electrolytic solution containing the bissilylamide magnesium salt is used as a non-noble metal. As a corrosion free electrolyte It can have more improved efficiency. The manufacturing method of the electrolyte solution does not undergo a separate crystallization process, so the yield is high and mass production is possible.

1 is a schematic diagram of a magnesium battery 1 according to an embodiment.
2A is a graph showing the results of measuring the oxidation potential of the electrolyte solutions of Example 1, Example 2, and Comparative Example 1. FIG.
2A is a graph showing the results of measuring the oxidation potential of the electrolyte solution of Example 4.
3 is a graph showing the measurement results of cyclic voltammetry for the electrolyte solution of Example 1. FIG.
4A is a graph showing measurement results of cyclic voltammetry for the electrolyte solutions of Examples 1, 2, and Comparative Example 1. FIG.
4B is a graph showing the measurement results of cyclic voltammetry for the electrolyte solution of Example 4. FIG.

Hereinafter, an electrolyte according to an embodiment of the present invention, a method for manufacturing the same, and a magnesium battery including the electrolyte will be described in detail. This is presented as an example, whereby the present invention is not limited, and the present invention is only defined by the scope of the claims to be described later.

In one aspect, there is provided an electrolytic solution comprising a cyclic or chain bissilylamide magnesium salt including two Si-N-Si cores and an N-Mg-N bond. The term "bissilylamide magnesium salt" as used herein refers to "bissilylamide magnesium salt" in the broad sense including "bissilylamide magnesium salt and derivatives derived therefrom".

In general, a magnesium battery includes a positive electrode, a negative electrode, and an ion conductive electrolyte, and as an ion conductive electrolyte, a Grignard-based magnesium salt that does not form a film on the negative electrode (RMgX (R = alkyl group or aryl group, X = Cl or Br) ) Is used. The electrochemical reaction of such a magnesium cell is, for example:

Positive ^{electrode: Mg → Mg 2 + + 2e} -

Negative electrode: Mg → Mg ^{+ 2} zMg _y MX + _{y + z} MX + 2e ^-

That is, during discharge, electrons are released from the cathode to the external circuit, and the generated magnesium ions pass through the electrolyte (oxidation reaction), and during charging, magnesium ions move to the cathode and are plated with metal to recover electrons (reduction reaction). ) Happens.

However, the electrolyte solution containing the Grignard magnesium salt may become electrochemically unstable due to the dominance of cations such as RMg ⁺ in a chemical equilibrium state. Due to this, the reversibiliyu of deposition/dissolution of magnesium is lowered, resulting in a decrease in efficiency.

The cyclic or chain bissilylamide magnesium salt according to one embodiment has a low HOMO energy level non-nucleophilic structure. In such a non-nucleophilic structure, MgCl ⁺ cations exist more predominantly than RMg ⁺ cations in a chemical equilibrium state, so that the magnesium deposition path becomes stable and is considered to be electrochemically stable.

For example, in the cyclic bissilylamide magnesium salt, the presence of two electron-rich Si around the N atom causes a steric hindrance effect around the N atom, and as a result, it can maintain chemical reactivity and is electrochemically stable. can do. In addition, it may have a wide range of oxidation potentials, and chemical reactivity may be minimized so as not to form a film on the cathode.

In addition, since the cyclic or chain bissilylamide magnesium salt does not contain halogen, the electrolyte solution containing the cyclic or chain bissilylamide magnesium salt is used as a non-noble metal. As a corrosion free electrolyte, it may have improved efficiency.

The cyclic or chain bissilylamide magnesium salt may include a magnesium salt represented by the following formula (1):

<Formula 1>

In Formula 1,

The A or M moieties are linked to form a ring or are not linked to form an open chain;

When the A or M moieties are linked to form a ring, CY1 or CY2 represents a 3 to 10 membered ring aromatic ring, an aliphatic ring, a hetero ring, or a 5 to 20 membered ring condensed ring;

R ₁ , R ₃ , R ₅ , R ₇ may be independently a substituted or unsubstituted linear C1-C10 alkyl group, a substituted or unsubstituted branched C3-C10 alkyl group, or a combination thereof;

R ₂ , R ₄ , R ₆ , R ₈ may be each independently a substituted or unsubstituted C6-C10 aryl group, a substituted or unsubstituted C6-C20 heteroaryl group, or a combination thereof.

When the A or M moiety in Formula 1 is connected to form a ring, the CY1 or CY2 may have an aromatic ring having 0 to 6 carbon atoms, an aliphatic ring, a hetero ring, or a condensed ring having 4 to 10 carbon atoms. I can. The CY1 or CY2 is, for example, 1,2,3-azadisiliridine, 1,2,4-azadisiletidine, 1,2,5-azadisilolidine ), 1,2,6-azadisilinane, 1,2-dihydro-1H-1,2,5-azadisilole (1,2-dihydro-1H-1,2,5-azadisilole ), or 1,2-dihydro-1,2,6-azadisiline, and the like, but is not limited thereto.

When the A or M moiety in Formula 1 is not connected to form an open chain, a methyl group may be connected to the Si atom.

"Substituted" in the "substituted" of the alkyl group, aryl group, and heteroaryl group used in Formula 1 is a halogen atom, a C1-C10 alkyl group substituted with a halogen atom (eg, CCF ₃ , CHCF ₂ , CH ₂ F, CCl _3, etc.), hydroxy group, nitro group, cyano group, amino group, amidino group, hydrazine, hydrazone, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, C1-C10 alkyl group, C1- It means substituted with a C10 heteroalkyl group, a C6-C10 aryl group, a C6-C10 heteroaryl group, or a C6-C10 heteroarylalkyl group.

Specific examples of the straight-chain C1-C10 alkyl group used in Formula 1 may include methyl, ethyl, or propyl, and specific examples of the branched C1-C10 alkyl group include sec-butyl, ter-butyl, neo- Butyl or iso-amyl.

The C6-C10 aryl group used in Formula 1 is used alone or in combination to mean an aromatic system containing one or more rings, and examples thereof include phenyl, naphthyl, or tetrahydronaphthyl. .

The C6-C20 heteroaryl group used in Chemical Formula 1 includes one or more heteroatoms selected from N, O, P, or S, and the remaining ring atoms are carbon, which is meant to be an organic compound, for example, pyridyl, etc. I can.

In Formula 1, R ₁ , R ₃ , R ₅ , R ₇ are, for example, independently of each other, 1 selected from methyl group, ethyl group, propyl group, butyl group, isopropyl group, isobutyl group, and t-butyl group It may contain more than one species.

In Formula 1, R ₂ , R ₄ , R ₆ , R ₈ are, for example, independently of each other, an unsubstituted C6-C10 aryl group, a C1-C10 alkyl group substituted with a halogen atom, a straight-chain C1-C10 It may include at least one selected from a C6-C10 aryl group substituted with an alkyl group, and a C6-C10 aryl group substituted with a branched C1-C10 alkyl group.

In the case where R ₂ , R ₄ , R ₆ , R ₈ as a substituent of the Si atom in Formula 1 contains an aryl group, a heteroaryl group, or a group consisting of a combination thereof, it is more stable than the case containing an alkyl group such as a methyl group. It can be electrochemically stable due to its electronic structure. As a result, the reversibility of deposition/elution of magnesium may be improved, and efficiency may be further improved.

The cyclic or chain bissilylamide magnesium salt may include, for example, a magnesium salt represented by Formula 2 or Formula 3:

<Formula 2> <Formula 3>

The concentration of the magnesium salt in the electrolyte may be 0.01 to 2.0M. For example, the concentration of the magnesium salt in the electrolyte may be 0.01 to 1.5M, for example, 0.01 to 1.0M. Within the above range, the magnesium salt is dissolved in the non-aqueous organic solvent, so that the magnesium ions may be easily dissociated.

The electrolyte may further include a non-aqueous organic solvent.

The non-aqueous organic solvent is tetrahydrofuran (THF), 2-methyl tetrahydrofuran, 2-methylfuran, ethyl alcohol, 4-methyldioxolane, 1,3-dioxolane, 1,4-dioxane, 1, 1-dimethoxyethane, 1,2-dimethoxymethane, ethylene carbonate, propylene carbonate, γ-butyrolactone, methyl formate, sulfolane, 3-methyl-2-oxazolidinone, dimethyl carbonate, hexane, toluene, Dimethyl ether, diethyl ether, methyl ethyl ether, propyl ether, methyl propyl ether, isopropyl ether, methyl isopropyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, bis 2-methoxy ethyl ether, and tetraethylene glycol It may include one or more selected from. However, the present invention is not limited thereto, and non-aqueous organic solvents commonly used in the art may be used.

The electrolyte may contain a magnesium salt represented by the following Chemical Formula 4 or Chemical Formula 5:

<Formula 4> <Formula 5>

In another aspect, a non-aqueous organic solvent; A cyclic or chain bissilylamide magnesium salt comprising two Si-N-Si cores and an N-Mg-N bond; And Lewis acid (Lewis acid); is provided an electrolyte containing.

The Lewis acid is, for example, comprising a ₃ AlCl, AlCl _x R _{'-x 3,} BCl _3, BCl _x R' _{-x 3,} and B (OR ') at least one selected from _3, where x is 0, 1, 2, 3 and R'is a substituted or unsubstituted linear C1-C10 alkyl group, a substituted or unsubstituted branched C3-C10 alkyl group, a substituted or unsubstituted C3-C10 cycloalkyl group, or a substituted or It may be an unsubstituted C6-C10 aryl group. The electrolyte solution to which the Lewis acid is added may increase the reversibility of deposition/elution of magnesium by widening the range of the oxidation potential. As a result, the efficiency characteristics of the electrolyte may be further improved.

The electrolyte may have a molar ratio of the magnesium salt to the Lewis acid of 1:10 to 10:1. In the electrolyte, for example, the molar ratio of the magnesium salt to the Lewis acid may be 1:8 to 8:1, and for example, the molar ratio of the magnesium salt to the Lewis acid may be 1:3 to 3:1 Can be When the molar ratio of the magnesium salt to the Lewis acid is within the above range, reversibility and efficiency characteristics of deposition/elution of magnesium can be greatly improved.

In another aspect, a cyclic or chain bissilylamide comprising two Si-N-Si cores and an N-Mg-N bond by adding a polar organic solvent to a cyclic or chain silylamide halide-containing magnesium salt. There is provided a method of preparing an electrolyte solution including; preparing an electrolyte solution of a magnesium salt.

The cyclic or chain bissilylamide magnesium salt may include a magnesium salt represented by the following formula (1):

<Formula 1>

In Formula 1,

The A or M moieties are linked to form a ring or are not linked to form an open chain;

When the A or M moieties are linked to form a ring, CY1 or CY2 represents a 3 to 10 membered ring aromatic ring, an aliphatic ring, a hetero ring, or a 5 to 20 membered ring condensed ring;

R ₁ , R ₃ , R ₅ , R ₇ may be independently a substituted or unsubstituted linear C1-C10 alkyl group, a substituted or unsubstituted branched C3-C10 alkyl group, or a combination thereof;

R ₂ , R ₄ , R ₆ , R ₈ may be each independently a substituted or unsubstituted C6-C10 aryl group, a substituted or unsubstituted C6-C20 heteroaryl group, or a combination thereof.

The manufacturing method of the electrolyte solution does not undergo a separate crystallization process, so the yield is high and mass production is possible. Since the prepared cyclic or chain bissilylamide magnesium salt does not contain halogen, the electrolytic solution containing the bissilylamide magnesium salt is used as a non-noble metal. As a corrosion free electrolyte It can have more improved efficiency.

The polar organic solvent is 1, 2-dioxane, 1, 3-dioxane, 1, 4-dioxane, tetrahydrofuran (THF), 2-methyl tetrahydrofuran, 2-methylfuran, ethyl alcohol, 4- Methyldioxolane, 1,3-dioxolane, 1,4-dioxane, 1,2-dimethoxyethane, dimethoxymethane, ethylene carbonate, propylene carbonate, γ-butyrolactone, methyl formate, sulfolane, 3 -Methyl-2-oxazolidinone, dimethyl carbonate, hexane, toluene, dimethyl ether, diethyl ether, methyl ethyl ether, propyl ether, methyl propyl ether, isopropyl ether, methyl isopropyl ether, ethylene glycol dimethyl ether, diethylene It may contain at least one selected from glycol dimethyl ether, bis 2-methoxy ethyl ether, tetraethylene glycol, tetraethylene glycol dimethyl ether, and hydrofluoroether (HFEs). The polar organic solvent is used in an excessive amount to precipitate and precipitate magnesium halide to form a cyclic or chain containing two Si-N-Si cores and an N-Mg-N bond from a cyclic or chain silylamide halide-containing magnesium salt. It makes it possible to separate the chain bissilylamide magnesium salt.

The manufacturing method of the electrolyte solution includes: preparing an electrolyte solution of a cyclic or chain type bissilylamide magnesium salt to which a Lewis acid is added by adding a Lewis acid solution to the electrolyte solution of the cyclic or chain type bissilylamide magnesium salt. I can. Since the type of Lewis acid is the same as described above, a description thereof will be omitted.

The molar ratio of the cyclic or chain bissilylamide magnesium salt to the Lewis acid may be 1:10 to 10:1. The molar ratio of the cyclic or chain bissilylamide magnesium salt to the Lewis acid may be 1:8 to 8:1, for example, the cyclic or chain bissilylamide magnesium salt to the Lewis acid The molar ratio of may be 1:3 to 3:1. When the molar ratio of the magnesium salt to the Lewis acid is within the above range, reversibility and efficiency characteristics of deposition/elution of magnesium can be greatly improved.

In another aspect, a positive electrode including a positive electrode active material for storing and releasing magnesium ions; A negative electrode including a negative electrode active material for storing and releasing magnesium ions; And a magnesium battery including the above-described electrolyte impregnated between the positive electrode and the negative electrode.

As a magnesium battery, for example, it may be prepared as follows.

First, the anode may be prepared as follows, for example.

For example, a positive electrode active material composition in which a positive electrode active material, a conductive material, a binder, and a solvent are mixed is prepared. The positive electrode active material composition is directly coated on a metal current collector to prepare a positive electrode plate. Alternatively, the positive electrode active material composition may be cast on a separate support, and then a film peeled from the support may be laminated on a metal current collector to prepare a positive electrode plate. The anode is not limited to the shapes listed above, but may be in a shape other than the above shape.

The positive electrode active material may include, for example, at least one selected from the group consisting of an oxide compound of a metal element, a halogen compound, a sulfide compound, a selenium compound, a phosphate compound, a phosphide compound, and a diboride compound. The metal elements are, for example, scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), molybdenum (Mo), It may contain at least one selected from the group consisting of lead (Pb), ruthenium (Ru), tungsten (W), zirconium (Zr), nickel (Ni), copper (Cu), and zinc (Zn).

The positive electrode active material is, for example, Co ₃ O ₄ , Mn ₂ O ₃ , Mn ₃ O ₄ , MoO ₃ , PbO ₂ , Pb ₃ O ₄ , RuO ₂ , V ₂ O ₅ , WO ₃ , Mg ₂ MnSiO ₄ , TiS ₂ , NiS ₂ , FeS ₂ , VS ₂ , ZrS ₂ , Mo ₃ O ₄ , Mo ₆ S ₈ , Mo ₆ Se ₈ , MoS ₆ Se ₂ , MoB ₂ , TiB ₂ and one selected from the group consisting of ZrB ₂ It may include more than one.

In addition to the above-described positive electrode active material, the positive electrode may additionally include a conventional general positive electrode active material or a magnesium composite metal oxide. Examples of the magnesium composite metal oxide are Mg(M _{1 - x} A _x )O ₄ (0≤x≤0.5, M is Ni, Co, Mn, Cr, V, Fe, Cu or Ti, and A is Al, B , Si, Cr, V, C, Na, K, or Mg) may be used.

As the conductive material, a carbon material having a high specific surface area, for example, carbon black, activated carbon, acetylene black, and a mixture of one or two or more of graphite fine particles may be used. In addition, electrically conductive fibers such as carbon fibers made from vapor-grown carbon or fibers produced by carbonizing pitch (by-products such as petroleum, coal, coal tar, etc.) at high temperature, and acrylic fibers (Polyacrylonitrile) can also be used as conductive materials. . Carbon fiber and carbon material with high specific surface area can be used at the same time. Electrical conductivity can be further improved by simultaneously using carbon fiber and a carbon material having a high specific surface area. In addition, it is a material that does not oxidize and dissolves in the charge/discharge range of the positive electrode, and a metallic conductive material having lower electrical resistance than the positive electrode active material can be used. For example, corrosion-resistant metals such as titanium and gold, carbides such as SiC or WC, and nitrides such as Si ₃ N ₄ and BN may be used, but are not necessarily limited to these, and any material that can be used as a conductive material in the art can be used. Do.

As the binder, vinylidene fluoride/hexafluoropropylene copolymer, polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, polytetrafluoroethylene and mixtures thereof, or styrene butadiene rubber-based polymer, etc. Although may be used, it is not limited thereto, and any one that can be used as a binder in the art may be used.

As the solvent, N-methylpyrrolidone, acetone, or water may be used, but are not limited thereto, and any solvent that can be used in the art may be used.

The metal current collector is not limited in material, shape, and manufacturing method, and an electrochemically stable material may be used. The metal current collector may be an aluminum foil having a thickness of 10 to 100 μm, an aluminum perforated foil having a thickness of 10 to 100 μm, and a hole diameter of 0.1 to 10 mm, an expanded metal, and a foamed metal plate. As the material of the metal current collector, in addition to aluminum, stainless steel, titanium, or the like may be used.

The contents of the positive electrode active material, the conductive material, the binder, and the solvent are generally used in magnesium batteries. One or more of the conductive material, the binder, and the solvent may be omitted depending on the use and configuration of the magnesium battery.

Next, the cathode is prepared.

In the magnesium battery, the negative electrode may include at least one selected from the group consisting of magnesium metal, magnesium metal-based alloy, magnesium intercalating compound, or carbon-based material. However, the present invention is not necessarily limited to these, and any one that can contain magnesium or that can occlude/release magnesium may be used as a negative electrode active material in the art.

Since the negative electrode determines the capacity of the magnesium battery, the negative electrode may be, for example, magnesium metal. As the magnesium metal-based alloy, an alloy of magnesium, such as aluminum, tin, indium, calcium, titanium, vanadium, and the like may be mentioned.

For example, the negative electrode may be a metallic magnesium having a thickness of generally 3 μm to 500 μm, and may be used in various forms such as films, sheets, foils, nets, porous materials, foams, and non-woven fabrics.

The oxidation potential of the electrolyte salt impregnated between the anode and the cathode may be 3.0V (vs. Mg/Mg ²⁺ ) or more. Since the magnesium salt has a wide range of oxidation potential, efficiency characteristics may be improved by increasing the reversibility of deposition/elution of magnesium.

The efficiency of the electrolyte may be 90% or more. For example, the efficiency of the electrolyte may be 91% or more, for example, the efficiency of the electrolyte may be 93% or more, and for example, the efficiency of the electrolyte may be 94% or more.

A separator may be additionally disposed between the anode and the cathode.

The separator is not limited as long as it is a composition capable of withstanding the environment of use of a magnesium battery, for example, a polymer nonwoven fabric such as a nonwoven fabric made of polypropylene or a nonwoven fabric made of polyphenylene sulfide, and the porosity of an olefin resin such as polyethylene or polypropylene. A film can be illustrated, and it is also possible to use these two or more types together.

In addition, the separator may be used that has low resistance to ion movement of the electrolyte and has excellent electrolyte-moisture ability. For example, as selected from glass fiber, polyester, Teflon, polytetrafluoroethylene (PTFE), or a combination thereof, it may be in the form of a non-woven fabric or a woven fabric.

For example, the separator may be manufactured according to the following method.

A polymer resin, a filler, and a solvent are mixed to prepare a separator composition. The separator composition may be directly coated and dried on the anode active material layer to form a separator. Alternatively, after the separator composition is cast and dried on a support, a separator film peeled off from the support may be laminated on an anode active material layer to form a separator.

The polymer resin used for manufacturing the separator is not particularly limited, and all materials used for the bonding material of the electrode plate may be used. For example, polyethylene, polypropylene, vinylidene fluoride/hexafluoropropylene copolymer, polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, or mixtures thereof may be used. The filler used in the manufacture of the separator may be inorganic particles, and the solvent may dissolve the polymer resin and form pores in the polymer resin upon drying, and any material generally used in the art may be used. .

In addition, the separator may be separately manufactured by other known common methods and laminated on the anode active material layer. For example, a dry manufacturing method in which polypropylene and polyethylene are melted and extruded to form a film, then annealed at a low temperature to grow crystal domains, and then stretched in this state to extend the amorphous region to form a microporous film. Can be used. For example, after mixing other low-molecular materials such as hydrocarbon solvents with polypropylene, polyethylene, etc., a film is formed, and then, a film in which the solvent or small molecules are gathered in an amorphous phase to form an island phase is prepared. A wet manufacturing method in which a microporous membrane is formed by removing a solvent or a low molecule using another volatile solvent may be used.

Further, the separator may additionally contain additives such as non-conductive particles, other fillers, and fiber compounds for the purpose of controlling strength, hardness, and heat shrinkage. For example, the separator may additionally include inorganic particles. By additionally including the inorganic particles, oxidation resistance of the separator may be improved, and deterioration of battery characteristics may be suppressed. The inorganic particles may be alumina (Al ₂ O ₃ ), silica (SiO ₂ ), or titania (TiO ₂ ). The average particle diameter of the inorganic particles may be 10nm to 5㎛. When the average particle diameter is less than 10 nm, the crystallinity of the inorganic particles is lowered, so that the addition effect is insignificant, and when the average particle diameter exceeds 5 μm, dispersion of the inorganic particles may be difficult.

The separator may have a multilayer structure including one or more polymer layers for the purpose of increasing tear strength or mechanical strength. For example, it may be a polyethylene/polypropylene laminate, a polyethylene/polypropylene/polyethylene laminate, a nonwoven fabric/polyolefin laminate, and the like.

1 is a schematic diagram of a magnesium battery 1 according to an embodiment. As shown in FIG. 1, the magnesium battery 1 includes a positive electrode 3, a negative electrode 2, and a separator 4. The above-described positive electrode 3, negative electrode 2 and separator 4 are wound or folded to be accommodated in the battery case 5. Subsequently, an organic electrolyte is injected into the battery case 5 and sealed with a cap assembly 6 to complete the magnesium battery 1. The battery case may have a cylindrical shape, a square shape, or a thin film shape. For example, the magnesium battery may be a large thin film type battery. The magnesium battery may be a magnesium ion battery.

A separator may be disposed between the positive electrode and the negative electrode to form a battery structure. After the battery structure is stacked in a bi-cell structure, it is impregnated with an organic electrolytic solution, and the resulting product is accommodated in a pouch and sealed to complete a magnesium polymer battery.

In addition, a plurality of the battery structures are stacked to form a battery pack, and such a battery pack can be used in all devices requiring a high capacity. For example, it can be used for laptop computers, smart phones, electric vehicles, and the like.

In addition, since the magnesium battery has excellent storage stability and thermal stability, it can be used in an energy storage system (ESS) and an electric vehicle (EV). For example, it can be used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEVs).

Hereinafter, specific embodiments of the present invention are presented. However, the examples described below are merely for illustrating or explaining the present invention in detail, and the present invention is not limited thereto.

In addition, information not described herein can be sufficiently technically inferred by those skilled in the art, and thus the description thereof will be omitted.

[Example]

(Preparation of electrolyte)

Manufacturing example 1: Preparation of magnesium salt

The ethyl magnesium chloride solution to which tetrahydrofuran (THF) was added to a 2M ethyl magnesium chloride solution (manufactured by Aldrich) was diluted to a concentration of 0.5M. The diluted ethyl magnesium chloride solution was cooled to 10°C. 1,1,3,3-tetramethyl-1,3-diphenyldisilazane (1,1,3,3-tetramethyl-1,3-diphenyldisilazane) of 1 equivalent (eq.) represented by the following Formula 6 (Manufactured by Aldrich) was diluted with anhydrous tetrahydrofuran (THF).

The diluted 1,1,3,3-tetramethyl-1,3-diphenyldisilazane (1,1,3,3-tetramethyl-1,3-diphenyldisilazane) solution was added to the 0.5M ethyl magnesium chloride solution. It was added dropwise for 30 minutes and stirred. Thereafter, the temperature of the mixture was raised to 25° C. and stirred at 25° C. for 1 hour. The mixture was heated at 50° C. for 8 hours and then cooled to room temperature.

To the mixture, an excess of anhydrous 1,4-dioxane (20 equivalents (eq.)) was added dropwise until a white MgCl ₂ precipitate was formed. Thereafter, the mixture was heated to 45° C. and stirred for 2 hours. The mixture was allowed to stand at 5°C overnight and then filtered. Thereafter, in order to remove the solvent from the mixture, the mixture was placed under reduced pressure, and the resulting sticky liquid was dried at 50° C. for 8 hours under vacuum to prepare a white powder of magnesium salt represented by the following formula (4):

<Formula 4>

<Formula 6>

Manufacturing example 2: Preparation of magnesium salt

The ethyl magnesium chloride solution to which tetrahydrofuran (THF) was added to a 2M ethyl magnesium chloride solution (manufactured by Aldrich) was diluted to a concentration of 0.8M. The diluted ethyl magnesium chloride solution was cooled to 10°C. 1 equivalent (eq.) of 2,2,5,5-tetramethyl-1,2,5-azadisilolidine (2,2,5,5-tetramethyl-1,2,5) represented by the following formula (7) -azadisilolidine) (manufactured by Hanchem) was diluted with anhydrous tetrahydrofuran (THF).

The diluted 2,2,5,5-tetramethyl-1,2,5-azadisilolidine (2,2,5,5-tetramethyl-1,2,5-azadisilolidine) solution was added to the 0.5M ethylmagnesium It was added dropwise to the chloride solution for 30 minutes and stirred. Thereafter, the temperature of the mixture was raised to 25° C. and stirred at 25° C. for 1 hour. The mixture was heated at 50? for 8 hours and then cooled to room temperature.

To the mixture, an excess of anhydrous 1,4-dioxane (20 equivalents (eq.)) was added dropwise until a white MgCl ₂ precipitate was formed. Thereafter, the mixture was heated to 45° C. and stirred for 2 hours. The mixture was allowed to stand at 5°C overnight and then filtered. Thereafter, in order to remove the solvent from the mixture, the mixture was placed under reduced pressure, and the resulting sticky liquid was dried at 50° C. for 8 hours under vacuum to prepare a white powder of magnesium salt represented by the following formula (5):

<Formula 5>

<Formula 7>

Example 1: Preparation of electrolyte

A colorless 1.0M AlCl ₃ solution dissolved in tetrahydrofuran (THF) was prepared. A solution prepared by dissolving the magnesium salt prepared in Preparation Example 1 in an appropriate volume of anhydrous tetrahydrofuran (THF) at room temperature in an appropriate amount was prepared.

The magnesium salt solution prepared in Preparation Example 1 was added dropwise to the 1.0M AlCl ₃ solution so that the molar ratio of the magnesium salt represented by Formula 4 to AlCl ₃ was 1:1, and then maintained at 12°C to add Lewis acid. Was prepared.

Example 2: Preparation of electrolyte

A colorless 1.0M AlCl ₃ solution dissolved in tetrahydrofuran (THF) was prepared. A solution prepared by dissolving the magnesium salt prepared in Preparation Example 1 in an appropriate volume of anhydrous tetrahydrofuran (THF) at room temperature in an appropriate amount was prepared.

The magnesium salt solution prepared in Preparation Example 1 was added dropwise to the 1.0M AlCl ₃ solution so that the molar ratio of magnesium salt to AlCl ₃ represented by Formula 4 was 1:2, and then maintained at 12°C to add Lewis acid. Was prepared.

Example 3: Preparation of electrolyte

A colorless 1.0M AlCl ₃ solution dissolved in tetrahydrofuran (THF) was prepared. A solution prepared by dissolving the magnesium salt prepared in Preparation Example 2 in an appropriate volume of anhydrous tetrahydrofuran (THF) at room temperature in an appropriate amount was prepared.

The magnesium salt solution prepared in Preparation Example 2 was added dropwise to the 1.0M AlCl ₃ solution so that the molar ratio of the magnesium salt represented by Chemical Formula 5 to AlCl ₃ was 1:1, and then maintained at 12°C to add Lewis acid. Was prepared.

Example 4: Preparation of electrolyte

A colorless 1.0M AlCl ₃ solution dissolved in tetrahydrofuran (THF) was prepared. A solution prepared by dissolving the magnesium salt prepared in Preparation Example 2 in an appropriate volume of anhydrous tetrahydrofuran (THF) at room temperature in an appropriate amount was prepared.

The magnesium salt solution prepared in Preparation Example 2 was added dropwise to the 1.0M AlCl ₃ solution so that the molar ratio of the magnesium salt represented by Chemical Formula 5 to AlCl ₃ was 1:2, and then maintained at 12°C to add Lewis acid. Was prepared.

Comparative example 1: Preparation of electrolyte

20 ml of tetrahydrofuran (THF) was added to 2M phenylmagnesium chloride to prepare a phenylmagnesium chloride magnesium salt solution. A 1M AlCl ₃ solution dissolved in tetrahydrofuran (THF) was added dropwise to the phenylmagnesium chloride magnesium salt solution so that the molar ratio of the phenyl magnesium chloride magnesium salt to AlCl ₃ was 2:1, and then maintained at 12?, and Lewis acid was added. The prepared electrolyte solution was prepared.

(Oxidation potential and cyclic voltammetry measurement)

Evaluation example 1: Oxidation potential and current circulation method ( cyclic voltammetry ) Measure

Oxidation potential and cyclic voltammetry (CV) were measured with less than 1 ppm of moisture and oxygen in a glove box in an argon atmosphere. Oxidation potential and cyclic voltammetry (CV) of the magnesium battery were measured at 25°C using a potentiometer (electrochemical interface (1287 ECI), manufactured by Solartron analytical). An Au disk was used as a working electrode and a magnesium metal foil was used as a counter electrode, and a glass filter was sandwiched between the working electrode and the counter electrode, and they were fixed to face each other. In addition, a magnesium metal wire as a reference electrode was fixed in a position not in contact with either the working electrode or the counter electrode. The working electrode, counter electrode, and reference electrode were placed in the electrolyte solutions prepared in Examples 1, 2, 4, and 1, and beaker-type batteries were respectively Was produced. Each of the above in the voltage range of about -1.0V to 3.5V (vs. Mg/Mg ^{2 +} ) at a rate of 10 mV/sec for the electrolyte solutions prepared in Example 1, Example 2, Example 4, and Comparative Example 1. The working electrode included in the beaker type cell was scanned to evaluate the oxidation potential. The results are shown in Table 1, Fig. 2A, and Fig. 2B.

division Oxidation potential (V _ox , V) Example 1 3.0 Example 2 3.0 Example 4 3.0 Comparative Example 1 2.9

Referring to Tables 1 and 2, the oxidation potential of the electrolyte solutions prepared in Example 1, Example 2, and Example 4 was 3.0V (vs. Mg/Mg ^{2 +} ) or higher, and prepared in Comparative Example 1 The oxidation potential of the electrolyte solution was 2.9V (vs. Mg/Mg ^{2 +} ), which was less than 3.0V. It can be seen that the oxidation potential of the electrolyte solutions prepared in Examples 1, 2, and 4 was increased by about 0.1 V compared to the oxidation potential of the electrolyte solutions prepared in Comparative Example 1.

In addition, for the electrolytes prepared in Example 1, Example 2, Example 4, and Comparative Example 1, the working electrodes included in each beaker-type battery prepared by the above method were scanned at a rate of 20 mV/sec to oxidize the electrolyte. The reduction properties, that is, the reversibility of the elution/deposition of magnesium were evaluated. The results are shown in FIGS. 3, 4A, and 4B. In addition, the efficiency was calculated using Equation 1 below to evaluate the reversibility. The results are shown in Table 2 below.

The "area of the CV curve at the time of magnesium elution (N1)" and the "area of the trapezoidal shape including the CV curve at the time of magnesium deposition (N2)" used to calculate the efficiency of Equation 1 below are shown in FIG. 3 as an example. In this case, it corresponds to the hatched areas "N1" and "N2" of FIG. 3, respectively.

<Equation 1>

Efficiency (%) = [(area of CV curve when eluting magnesium (N1))/(area of trapezoidal shape including CV curve when depositing magnesium (N2))] x 100

division efficiency(%) Example 1 100 Example 2 100 Example 4 94.7 Comparative Example 1 84.9

Referring to Table 2 and FIGS. 3 and 4, the efficiencies of the electrolyte solutions prepared in Example 1, Example 2, and Example 4 were 100%, 100%, and 94.7%, respectively, and the electrolyte solution prepared in Comparative Example 1 The efficiency of was 84.9%. It can be seen that the efficiency of the electrolyte solution prepared in Example 1, Example 2, and Example 4 was improved from about 10% to about 15% compared to the efficiency of the electrolyte solution prepared in Comparative Example 1.

Thus, the redox characteristics of the electrolytes prepared in Examples 1, 2 and 4, that is, the reversibility of the elution/deposition of magnesium, was the redox characteristics of the electrolyte prepared in Comparative Example 1, that is, the elution/deposition of magnesium. It can be seen that it is improved compared to the reversibility.

Although a preferred embodiment of the present invention has been described above, the present invention is not limited thereto, and it is possible to implement various modifications within the scope of the claims, the detailed description of the invention, and the accompanying drawings. It is natural to fall within the scope of the invention.

1: magnesium battery 2: negative electrode 3: positive electrode 4: separator 5: battery case 6: cap assembly

Claims (22)

An electrolytic solution comprising a cyclic or chain bissilylamide magnesium salt containing two Si-N-Si cores and an N-Mg-N bond. The electrolytic solution of claim 1, wherein the cyclic or chain bissilylamide magnesium salt comprises a magnesium salt represented by the following formula (1):
<Formula 1>

In Formula 1,
The A or M moieties are linked to form a ring or are not linked to form an open chain;
When the A or M moieties are linked to form a ring, CY1 or CY2 represents a 3 to 10 membered ring aromatic ring, an aliphatic ring, a hetero ring, or a 5 to 20 membered ring condensed ring;
R ₁ , R ₃ , R ₅ , R ₇ are each independently a substituted or unsubstituted linear C1-C10 alkyl group, a substituted or unsubstituted branched C3-C10 alkyl group, or a combination thereof;
R ₂ , R ₄ , R ₆ , R ₈ are each independently a substituted or unsubstituted C6-C10 aryl group, a substituted or unsubstituted C6-C20 heteroaryl group, or a combination thereof. The method of claim 2, wherein when the A or M moieties are connected to form a ring, the CY1 or CY2 is an aromatic ring having 0 to 6 carbon atoms, an aliphatic ring, a hetero ring, or a condensed ring having 4 to 10 carbon atoms. The electrolyte solution representing. The method of claim 2, wherein the R ₁ , R ₃ , R ₅ , R ₇ are each independently at least one selected from a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, and a t-butyl group. Electrolyte containing a. The method of claim 2, wherein the R ₂ , R ₄ , R ₆ , R ₈ are independently of each other an unsubstituted C6-C10 aryl group, a C1-C10 alkyl group substituted with a halogen atom, a straight-chain C1-C10 alkyl group An electrolyte comprising at least one selected from a substituted C6-C10 aryl group and a C6-C10 aryl group substituted with a branched C1-C10 alkyl group. The electrolyte according to claim 1, wherein the cyclic or chain bissilylamide magnesium salt comprises a magnesium salt represented by the following formula (2) or (3):
<Formula 2><Formula3>

The electrolytic solution of claim 1, wherein the concentration of the magnesium salt in the electrolytic solution is 0.01M to 2.0M. The electrolytic solution of claim 1, wherein the electrolytic solution further comprises a non-aqueous organic solvent. The method of claim 8, wherein the non-aqueous organic solvent is 1, 2-dioxane, 1, 3-dioxane, 1, 4-dioxane, tetrahydrofuran (THF), 2-methyl tetrahydrofuran, and 2-methyl Furan, ethyl alcohol, 4-methyldioxolane, 1,3-dioxolane, 1,4-dioxane, 1,2-dimethoxyethane, dimethoxymethane, ethylene carbonate, propylene carbonate, γ-butyrolactone, methyl Formate, sulfolane, 3-methyl-2-oxazolidinone, dimethyl carbonate, hexane, toluene, dimethyl ether, diethyl ether, methyl ethyl ether, propyl ether, methyl propyl ether, isopropyl ether, methyl isopropyl ether, An electrolytic solution comprising at least one selected from ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, bis 2-methoxy ethyl ether, and tetraethylene glycol. The electrolyte according to claim 8, wherein the electrolyte comprises a magnesium salt represented by the following Formula 4 or Formula 5:
<Formula 4><Formula5>

Non-aqueous organic solvents;
A cyclic or chain bissilylamide magnesium salt comprising two Si-N-Si cores and an N-Mg-N bond; And
Lewis acid; electrolyte containing. The method of claim 11, wherein the Lewis acid comprises at least one selected from AlCl ₃ , AlCl _x R'3 _-x , BCl ₃ , BCl _x R'3 _-x , and B(OR') ₃ , wherein x is 0, 1, 2, or 3 and R'is a substituted or unsubstituted linear C1-C10 alkyl group, a substituted or unsubstituted branched C3-C10 alkyl group, a substituted or unsubstituted C3-C10 cycloalkyl group, Or a substituted or unsubstituted C6-C10 aryl group electrolyte. The electrolytic solution of claim 11, wherein the electrolytic solution has a molar ratio of the magnesium salt to the Lewis acid of 1:10 to 10:1. The electrolyte according to claim 11, wherein the electrolytic solution has a molar ratio of the magnesium salt to the Lewis acid of 1:3 to 3:1. An electrolyte solution of a cyclic or chain bissilylamide magnesium salt containing two Si-N-Si cores and an N-Mg-N bond by adding a polar organic solvent to a cyclic or chain silylamide halide-containing magnesium salt. The method of manufacturing an electrolyte solution comprising a; The method of claim 15, wherein the cyclic or chain bissilylamide magnesium salt comprises a magnesium salt represented by the following formula (1):
<Formula 1>

In Formula 1,
The A or M moieties are linked to form a ring or are not linked to form an open chain;
When the A or M moieties are linked to form a ring, CY1 or CY2 represents a 3 to 10 membered ring aromatic ring, an aliphatic ring, a hetero ring, or a 5 to 20 membered ring condensed ring;
R ₁ , R ₃ , R ₅ , R ₇ are each independently a substituted or unsubstituted linear C1-C10 alkyl group, a substituted or unsubstituted branched C3-C10 alkyl group, or a combination thereof;
R ₂ , R ₄ , R ₆ , R ₈ are each independently a substituted or unsubstituted C6-C10 aryl group, a substituted or unsubstituted C6-C20 heteroaryl group, or a combination thereof. The method of claim 15, wherein the polar organic solvent is 1, 2-dioxane, 1, 3-dioxane, 1, 4-dioxane, tetrahydrofuran (THF), 2-methyltetrahydrofuran, 2-methylfuran , Ethyl alcohol, 4-methyldioxolane, 1, 2-dimethoxyethane, ethylene carbonate, propylene carbonate, ν-butyrolactone, methyl formate, sulfolane, 3-methyl-2-oxazolidinone, dimethyl carbonate, Hexane, toluene, dimethyl ether, diethyl ether, methyl ethyl ether, propyl ether, methyl propyl ether, isopropyl ether, methyl isopropyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, bis(2-methoxyethyl) A method for producing an electrolyte solution comprising at least one selected from ether, tetraethylene glycol dimethyl ether, and hydrofluoroether (HFEs). The method of claim 15, comprising: preparing an electrolyte solution of a cyclic or chain type bissilylamide magnesium salt to which a Lewis acid is added by adding a Lewis acid solution to the electrolytic solution of the cyclic or chain type bissilylamide magnesium salt. Method for producing an electrolyte. The method of claim 18, wherein the molar ratio of the cyclic or chain bissilylamide magnesium salt to the Lewis acid is 1:10 to 10:1. A positive electrode including a positive electrode active material for storing and releasing magnesium ions;
A negative electrode including a negative electrode active material for storing and releasing magnesium ions; And
A magnesium battery comprising the electrolyte according to any one of claims 1 to 14 impregnated between the positive electrode and the negative electrode. The magnesium battery according to claim 20, wherein the electrolyte has an oxidation potential of 3.0 V (vs. Mg/Mg ^{2 +} ) or higher. The magnesium battery according to claim 20, wherein the electrolyte has an efficiency of 90% or more.

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