JP2007169262A - Lithium dicyano triazolate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithium dicyano triazolate which can favorably be used for an electrolyte forming an ion conductor of a battery having a charge and discharge mechanism such as a lithium polymer secondary battery etc., which requires long-term reliability, because it has high ion conductivity, it does not corrode an electrode, and it is stable over time. <P>SOLUTION: This lithium dicyano triazolate has a water content of not higher than 1,000 ppm, and an excess acid content or an excess base content of less than 0.2×10<SP>-3</SP>mol/g. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to lithium dicyanotriazolate. More specifically, the present invention relates to lithium dicyanotriazolate that is preferably used as an electrolyte of a lithium battery.

Lithium dicyanotriazolate (LiDCTA) is a lithium salt containing no halogen. On the other hand, as a lithium salt containing halogen, LiClO ₄ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiSO ₃ CF ₃ , LiSO ₃ C ₂ F ₅ , LiBF ₄ , LiPF ₆ , LiAsF _{6 and the} like, and are generally used as an electrolyte (ion conductor) of a lithium battery. However, such a lithium salt containing halogen has room for improvement in terms of sufficiently satisfying stability, safety, and conductivity required as an electrolyte of a lithium battery.

On the other hand, an anion salt ion conductive material having a high conductivity and having a five-membered ring is disclosed. As an example of the anion salt having a five-membered ring, the above-described LiDCTA containing no halogen is disclosed (for example, see Patent Document 1). Moreover, the following methods are generally known as a manufacturing method of LiDCTA (for example, refer patent document 1, nonpatent literature 1). First, diaminomaleonitrile (200 mmol) is added to 250 ml of an aqueous solution acidified with 200 mmol of hydrochloric acid to form a slurry. While stirring this, while maintaining the temperature at 0 ° C., the brown reaction mixture obtained by adding 1 equivalent of sodium nitrite was filtered and extracted three times with ether, and the extract was evaporated. Thereafter, the ether is evaporated to dryness to obtain crude dicyanotriazole (HDCTA). The crude HDCTA thus obtained is sublimated twice at 80 ° C. to obtain purified HDCTA. Next, treatment with a slight excess of lithium carbonate relative to the HDCTA, centrifugation of the cloudy solution, and drying of the supernatant under reduced pressure yield LiDCTA.

On the other hand, a general lithium battery has a positive electrode and a negative electrode formed from an active substance, and an electrolyte solution composed of an organic solvent in which a lithium salt such as LiPF ₆ is dissolved as a solute, between the positive electrode and the negative electrode. For example, in the case of a lithium ion secondary battery, it is known that repeated charging and discharging may cause electrolyte leakage and deterioration due to halogen. Is continuing.

On the other hand, polymer electrolytes that are highly safe and have no risk of liquid leakage are drawing attention. LiDCTA, which is expected as a lithium salt in place of LiN (SO ₂ CF ₃ ) ₂ used as such a polymer electrolyte, still exhibits the high charge and discharge characteristics required as an electrolyte for lithium batteries for a long period of time. There was room for improvement.
CA2194127 (pages 89 and 99) Egashira and 4 others, Lithium Dicyanotriazolate as a Lithium Salt for Poly (ethylene oxide) Based Polymer Electolytes, Electrochemical and Solid-State Letters (Electrochemical and Solid-State Letters), 2003, Vol. 6, No. 4, p. A71-A73

The present invention has been made in view of the above-described situation. When used as an electrolyte for a lithium battery, the present invention provides a lithium battery having excellent charge / discharge characteristics and a long-term reliability capable of practical use. The object is to provide an azolate.

The present inventor has made various studies on triazolates having a triazole skeleton. Assuming that dicyanotriazolate (DCTA) in which two cyano groups (—CN) are introduced as substituents is used, electrosuction is achieved by introducing two cyano groups. The electrolyte containing lithium dicyanotriazolate (LiDCTA), which is a lithium salt, has excellent basic performance such as electrochemical stability such as high ion conductivity and high stability. It was noted that it is useful as an electrolyte of a lithium battery because it can be exhibited. And when the water content of LiDCTA and the excess acid amount or the excess base amount are within a predetermined range, or the Hazen value is within a predetermined range, excellent charge / discharge characteristics required as an electrolyte of a lithium battery are exhibited. On the other hand, it has been found that side reactions with the electrodes and deterioration of the electrolyte can be prevented. In addition, it has been found that a lithium battery having long-term reliability can be put into practical use, and the inventors have conceived that the above problems can be solved brilliantly. Moreover, since such LiDCTA does not have a fluorine atom, it can suppress the corrosiveness to the electrode etc. resulting from the fluorine atom and can function stably over time, and constitutes an electrolyte. It has been found that it functions as a material and can be suitably used for an electrochemical device, and has reached the present invention.

That is, the present invention is a lithium dicyanotriazolate in which the amount of water of lithium dicyanotriazolate is 1000 ppm or less, and the amount of excess acid or excess base is less than 0.2 × 10 ⁻³ mol / g. .
The lithium dicyanotriazolate of the present invention is also preferably a lithium dicyanotriazolate having a Hazen value of 200 or less.

Lithium dicyanotriazolate (LiDCTA) in the present invention is a compound having a structure represented by the following general formula (1).

The water content is preferably a water content relative to the solid mass of LiDCTA. Moreover, it is preferable to measure the said moisture content as follows.
In a glove box controlled in an atmosphere with a temperature of 20 ° C. and a dew point of −60 ° C. or below, 0.2 g of LiDCTA is dissolved in 1.8 g of dehydrated methanol, and the water content (Appm) of this solution is curled. Measure by Fisher method. Similarly, the water content (Bppm) of dehydrated methanol used for preparing the previous solution is also measured by the Karl Fischer method. And the moisture content (Cppm) of LiDCTA is calculated by the following formula.
C = (A × (1.8 + 0.2)) − B × 1.8) /0.2

In the lithium dicyanotriazolate, the amount of lithium cation and dicyanotriazolate anion contained in the lithium salt is the standard, and the amount of lithium cation is less than the amount of dicyanotriazolate anion. This is an excess of acid, and the degree is expressed by the amount of excess acid. In addition, based on the fact that the amount of lithium cation and dicyanotriazolate anion contained in the lithium salt is the same, the amount of lithium cation is larger than the amount of dicyanotriazolate anion. The state is expressed by the amount of excess base.

The excess acid amount or excess base amount is preferably measured as follows.
LiDCTA (0.1 g) is dissolved in distilled water (9.9 g) to prepare a 1% aqueous solution, and the pH is measured with a commercially available pH meter. If the pH at this time is 7 or less, neutralization titration is performed with a 0.1 M aqueous sodium hydroxide solution. While measuring the pH, when the volume of the 0.1 M aqueous sodium hydroxide solution required to reach the inflection point is Vml, the excess acid amount Xmol / g is calculated by the following formula.
X = 0.1 × f × V / 1000 / 1.0 (f: titer of aqueous sodium hydroxide)
If the pH at this time exceeds 7, neutralization titration with 0.1 M hydrochloric acid is performed. While measuring pH, when the volume of 0.1 M required to reach the inflection point was V ′ ml, the excess base amount Ymol / g is calculated by the following formula.
Y = 0.1 × f × V ′ / 1000 / 1.0 (f: hydrochloric acid titer)
In addition, when the pH of the 1% aqueous solution of LiDCTA is 6-8, it can also be titrated with a 0.1N aqueous sodium hydroxide solution after adding 0.1N hydrochloric acid to lower the pH of the aqueous solution to 6 or less. In this case, the volume of 0.1N hydrochloric acid added first is V _H (titer; f _H ), and the volume of 0.1N sodium hydroxide aqueous solution added until reaching the inflection point is V _Ne (titer; When f _Ne ), the excess acid amount / excess base amount calculation is calculated by the following equation.
When V _H × f _H ≦ V _Ne × f _Ne , X = 0.1 × f × (V _Ne × f _Ne −V _H × f _H ) /1000/0.1
For _{V H × f H ≧ V Ne} × f Ne, Y = 0.1 × f × (V H × f H -V Ne × f Ne) /1000/0.1

The lithium dicyanotriazolate of the present invention has a water content of more than 1000 ppm, and / or an excess acid amount or an excess base amount of 0.2 × 10 ⁻³ mol / g or more. When used as an electrolyte of a lithium battery, there is a possibility that the charge / discharge characteristics are excellent and long-term reliability cannot be achieved. Lithium dicyanotriazolate having a water content exceeding 1000 ppm and / or an excess acid amount or an excess base amount of 0.2 × 10 ⁻³ mol / g or more is a reaction with an active material of the positive electrode or the negative electrode or an electrolyte. Therefore, the effects of the invention may not be fully achieved. That is, as will be described later, at the time of discharging, very reactive lithium is generated in the negative electrode, so when the amount of water and impurities contained in lithium dicyanotriazolate, which is a material used for lithium batteries, is high, In the negative electrode, reactions other than the oxidation-reduction reaction of Li → Li ⁺ + e ⁻ occur, for example, 2Li + 2H ₂ O → 2LiOH + H ₂ ↑, etc. Will be hindered. Moreover, since the internal pressure rises due to the generation of hydrogen, the safety of the battery can be lowered. This can be judged by comparing the performance of the battery after repeating a certain charge / discharge cycle in a reactivity evaluation test with a Li foil electrode described later and a charge / discharge test using a coin battery. (1) Among forms of (1) to (2), when the amount of water exceeds 1000 ppm and (2) the amount of excess acid or excess base is 0.2 × 10 ⁻³ mol / g or more When at least one form is satisfied, an irreversible reaction may occur on the surface of the Li foil in the reactivity evaluation test with the Li foil electrode, and precipitates may be seen. In addition, even when the surface of the Li foil is not observed in the reactivity evaluation test with the Li foil electrode, in the charge / discharge test using a coin battery, an inactive component due to an irreversible reaction is generated inside the electrode, so that constant charge / discharge is achieved. The discharge capacity after the cycle test may decrease, or the resistance value between the electrodes may increase. However, when the water content is less than 1000 ppm and the excess acid amount or excess base amount is less than 0.2 × 10 ⁻³ mol / g, reactions other than the redox reaction of Li → Li ⁺ + e ⁻ occur. Therefore, a battery having excellent charge / discharge characteristics and long-term reliability can be provided. The amount of water is preferably 800 ppm or less. More preferably, it is 500 ppm or less. Most preferably, it is 200 ppm or less. A more preferable upper limit of the excess acid amount or the excess base amount is 0.18 × 10 ⁻³ mol / g.

The Hazen value is preferably measured as follows.
It is measured by dissolving 0.1 g of LiDCTA in 9.9 g of distilled water, preparing a 1% aqueous solution, and comparing the hue with a Hazen standard sample visually. At this time, the LiDCTA aqueous solution is placed in a container equivalent to the Hazen standard sample for comparison.

Lithium dicyanotriazolate having a Hazen value exceeding 200 may not be able to achieve the effects of the invention sufficiently. A more preferred upper limit is 180.

The method for producing lithium dicyanotriazolate of the present invention preferably includes a step of synthesizing dicyanotriazole (HDDCTA), a step of synthesizing lithium dicyanotriazolate (LiDCTA), and a step of drying LiDCTA. That is, the lithium dicyanotriazolate of the present invention is preferably produced by a production method including a step of synthesizing HDCTA, a step of synthesizing LiDCTA, and a step of drying LiDCTA.

In the step of synthesizing HDTA, diaminomaleonitrile is dispersed in an acidic aqueous solution, sodium nitrite is added to the dispersion, dicyanotriazole (HDTA) is synthesized, and after the reaction, an organic solvent is added and extracted. It is preferable to purify to obtain HDCTA.

Examples of the acidic aqueous solution in which the diaminomaleonitrile is dispersed include mineral acids such as sulfuric acid, hydrochloric acid, hydrogen bromide, nitric acid and phosphoric acid; halogenated carboxylic acids such as chloroacetic acid, dichloroacetic acid, trichloroacetic acid and trifluoroacetic acid: Examples include sulfonic acids such as methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and dodecylbenzenesulfonic acid: dissolved in water. From the standpoint of preventing the reaction kettle from corroding, sulfuric acid is preferably dissolved in water. The diaminomaleonitrile is preferably 5 to 70% based on the reaction mixture. More preferably, it is 10 to 50%.

The amount of sodium nitrite added is preferably 1.00 to 1.15 times that of HDCTA. Thereby, the Hazen value of LiDCTA in the present invention can be effectively reduced. More preferably, it is 1.03 to 1.12 times.
In the synthesis of HDCTA, sodium nitrite may be added by adding a solid or an aqueous solution, but is preferably an aqueous solution.

The organic solvent may be extracted by synthesizing dicyanotriazole (HDTA) and adding the organic solvent to the reaction solution. It is preferable that what was obtained by drying and solidifying the obtained solid (HDDCA) is extracted with an organic solvent. Thereby, the Hazen value of LiDCTA obtained can be reduced effectively.
The extraction solvent is not particularly limited, and ether solvents such as diisopropyl ether, diethyl ether, dipropyl ether, methyl butyl ether, and dibutyl ether: cyclic ethers such as tetrahydrofuran and dioxane, dimethoxyethane, methyl cellosolve, ethyl cellosolve, Solvents having ether or ester groups derived from ethylene glycol or propylene glycol such as methoxypropylene glycol: ketones such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl butyl ketone, ethyl isobutyl ketone, cyclopentanone Solvent; ester solvents such as ethyl acetate, propyl acetate, butyl acetate, more preferably diethyl ether, dipropyl ether, diisopropyl ether Ether, methyl butyl ether, ether solvents or ethyl acetate and di-butyl ether, propyl acetate, an ester solvent such as butyl acetate.

The above-mentioned purification method of HDCTA includes a method in which the HDCTA extracted solution is used to perform activated carbon treatment, extraction, crystallization, sublimation of HDCTA obtained by evaporation of the extraction solvent or crystallization, and the like. These may be carried out alone or in combination, but it is preferred to carry out by sublimation. The sublimation temperature is preferably 120 to 130 ° C. in that the sublimation time can be reduced. More preferably, it is 123-127 degreeC. When the sublimation temperature exceeds 130 ° C., side reactions such as HDCTA decomposition and amidation may occur, which is not preferable. The sublimation pressure is preferably 50 Pa or less. More preferably, it is 30 Pa or less. The number of sublimation times of HDCTA is not particularly limited, but is preferably one from the viewpoint of economy. Thus, a form in which the lithium dicyanotriazolate of the present invention is synthesized using HDCTA purified by sublimation is also a preferred form of the present invention.

The step of synthesizing lithium dicyanotriazolate (LiDCTA) is preferably performed by adding a lithiation reagent to HDTA to synthesize lithium dicyanotriazolate (LiDCTA) and drying. Here, examples of the lithiation reagent include lithium carbonate, lithium hydroxide, lithium metal and the like, but it is preferable to use lithium carbonate because high purity products are commercially available and easily available.

In the LiDCTA synthesis step, the reaction temperature is preferably 50 ° C. or lower. When the temperature exceeds 50 ° C., a by-product in which the cyano group undergoes an addition reaction with water may be generated.
The solvent used for the LiDCTA synthesis solvent is not particularly limited, and the following two preferred forms are mentioned in order to react HDCTA with an equivalent amount of the lithiation reagent. One is a method in which water is used as a solvent, whereby the reaction can be completed in one step by reacting HDCTA with an equivalent amount of a lithiating reagent. In this case, it is preferable to complete the reaction at pH 6 to 8 as an end point. When the pH is lower than 6 or higher than 8, an excessive acid or base may remain in the system even though water is used, which is not preferable. Another preferred method is a method using a solvent other than water. In this case, when HDCTA is reacted with an equivalent amount of a lithiating reagent, the reaction is incomplete, and the acid or base is not present in the system. May remain. In this case, it is preferable to complete the reaction at pH 6 to 8 as an end point. When the pH is lower than 6 or higher than 8, a large excess of acid or base may remain in the system, which is not preferable. In this case, excess acid or base can be removed by purification after the reaction.
The LiDCTA may be purified as necessary. The purification method is not particularly limited, and examples thereof include activated carbon treatment using a solvent that dissolves LiDCTA, extraction, and crystallization.

Examples of the method for drying LiDCTA include reduced pressure drying, fluidized bed drying, solvent azeotropic drying, spray drying, molecular sieve drying, and the like. These may be performed alone or in combination.
In the case of solvent azeotrope, toluene, hexane, cyclohexane, diethyl ether, dipropyl ether, diisopropyl ether, methyl butyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane and other ether solvents; acetonitrile, propionitrile and other nitriles Solvents: Alcohol solvents such as ethanol, propanol, isopropipanol, butanol; Ketone solvents such as acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl butyl ketone, ethyl isobutyl ketone, cyclopentanone; methyl acetate Ester solvents such as ethyl acetate, propyl acetate, and butyl acetate; carbonate solvents such as dimethyl carbonate can be used. Nitrile is preferable.
The solvent is preferably a dehydrated solvent from the viewpoint of drying speed. The method for dehydrating the solvent is not particularly limited, and examples include a dehydrating method using a molecular sieve.

In the solvent azeotropy, the azeotropic temperature is preferably 40 ° C. or higher and 140 ° C. or lower. If the azeotropic temperature is lower than 40 ° C., the azeotropic composition of water and the azeotropic solvent becomes closer to the solvent, which is not preferable because the drying efficiency is lowered. On the other hand, when the azeotropic temperature exceeds 140 ° C., the by-product that has caused the amidation reaction may be extremely generated, which is not preferable.
The following method is a preferred embodiment in which azeotropic dehydration is efficiently performed while suppressing the formation of the amidated product. That is, in the initial dehydration step where the water content in the system is high, dehydration is performed at a low temperature, and then the temperature is raised while dehydrating the system while confirming the amount of water reduction.
The time required for such an azeotropic dehydration step is not particularly limited, but it is preferable to carry out an appropriate time while confirming the amount of water in the system. If the azeotropic dehydration time is short, it is not preferable because it is not dried to a desired water content, and if the azeotropic dehydration time is too long, it is not preferable because the amidation reaction with the remaining water proceeds.

In the case of molecular sieve drying, LiDCTA can be reduced by dissolving LiDCTA in a solvent, adding a commercially available molecular sieve, and then drying the solvent. Examples of the solvent for dissolving LiDCTA include methanol, ethanol, n-propanol, isopropanol, n-butanol, s-butanol, t-butanol, acetone, methyl ethyl ketone, acetonitrile, propylene carbonate, and the like. Since a process is also required, it is desirable to select according to the usage conditions of LiDCTA. The molecular sieve to be added is not particularly limited, and various commercially available molecular sieves can be used. However, since there is elution from the molecular sieve, it is desirable to select it according to the use conditions of LiDCTA. For a lithium battery, for example, Li-A obtained from Union Showa, in which sodium constituting the molecular sieve is replaced with lithium is preferable.

In the step of synthesizing LiDCTA, it is preferable that the LiDCTA is dried by molecular sieving and toluene azeotropy. Thereby, the moisture content of LiDCTA can be reduced effectively.

In the LiDCTA solvent devolatilization step, the drying temperature is preferably 140 ° C. or lower. When the temperature exceeds 140 ° C., a by-product that causes the amidation reaction may be extremely produced.

The LiDCTA is also preferably such that the content of amidated product in LiDCTA is 1.5% by mass or less. That is, a form in which the lithium dicyanotriazolate has an amidation content of 1.5% by mass or less is also a preferred form of the present invention. More preferably, it is 0.5 mass% or less, More preferably, it is 0.3 mass% or less, Most preferably, it is 0.2 mass% or less. If the content of the amidated compound exceeds 1.5% by mass, an inert species due to an irreversible reaction is formed on the electrode surface, which may affect the electrochemical characteristics. That is, when it exceeds 1.5 mass%, there is a possibility that precipitates are generated due to an irreversible reaction occurring on the surface of the Li foil in the reactivity evaluation test with the Li foil electrode. Even if it is not found on the surface of the Li foil in the reactivity evaluation test, in the charge / discharge test using a coin battery, an inactive component due to an irreversible reaction is generated inside the electrode, so that the discharge capacity after a certain charge / discharge cycle test is increased. It may not be sufficient, or the resistance value between the electrodes may increase.

The content of the amidated product can be measured as follows.
(Quantification method of amidated product)
The amidated product is quantified using an ion chromatograph ICS-3000 manufactured by Dionex. The eluent 1.7 mM-NaHCO ₃ /1.8 mM-Na ₂ CO ₃ aqueous solution is used, AS4A-SC is used for the column, and the amidated product content (amidated product amount) is determined by the following formula.
Amidation amount (mass%) = (ratio obtained from peak area of amidation) / (ratio obtained from peak area of LiDCTA + ratio obtained from peak area of amidation) × 100

The LiDCTA is preferably contained in the electrolyte of a lithium battery. Depending on the function and configuration of the lithium battery used, such as a primary battery, a lithium ion secondary battery, or a lithium polymer secondary battery, the electrolyte, separator, positive electrode, A combination with a negative electrode or the like can be appropriately selected.
For example, as an electrolyte, by adding LiDCTA to an organic solvent and / or a polyether polymer or an acrylic polymer described later, ion conduction suitable for a primary battery, a lithium ion secondary battery, and a lithium polymer secondary battery. An electrolyte having the property can be obtained. At this time, a separator can be used as necessary, unless the membrane strength is sufficiently obtained with an electrolyte containing a polymer.
Examples of the base material for the polymer electrolyte include polyether copolymers such as polyethylene oxide and polypropylene oxide. Polyethylene oxide is preferable.
The ratio of LiDCTA in the polymer electrolyte is preferably 10 to 35% by mass. If it is less than 10% by mass, sufficient conductivity may not be obtained, and if it exceeds 25% by mass, LiDCTA may not be sufficiently dissolved. Preferably, it is 15-30 mass%.

It is preferable that the polymer electrolyte does not contain a solvent. However, when sufficient film strength can be maintained, the polymer electrolyte may contain 1 to 99% by mass of a solvent in 100% by mass of the electrolyte material. If it is less than 1% by mass, the ionic conductivity will not be sufficiently improved, and if it exceeds 99% by mass, the stability will not be sufficiently improved due to volatilization of the solvent or the like. As a lower limit, Preferably, it is 1.5 mass%, More preferably, it is 20 mass%, More preferably, it is 50 mass%. As an upper limit, Preferably, it is 85 mass%, More preferably, it is 75 mass%, More preferably, it is 65 mass%. As a range, the solvent amount is preferably 50 to 85% by mass.

The solvent is not particularly limited as long as it can improve the ionic conductivity. For example, an organic solvent is suitable.
Examples of the organic solvent include ethers such as 1,2-dimethoxyethane, tetotahydrofuran, 2-methyltetrahydrofuran, crown ether, triethylene glycol methyl ether, tetraethylene glycol dimethyl ether, dioxane; ethylene carbonate, Carbonates such as propylene carbonate, diethyl carbonate, methyl ethyl carbonate; chain carbonates such as dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, diphenyl carbonate, methyl phenyl carbonate; ethylene carbonate, propylene carbonate, 2,3-dimethyl carbonate Cyclic carbonates such as ethylene, butylene carbonate, vinylene carbonate, 2-vinylethylene carbonate; methyl formate, methyl acetate, propionic acid, methyl propionate, ethyl acetate, propyl acetate, vinegar Aliphatic carboxylic acid esters such as butyl and amyl acetate; Aromatic carboxylic acid esters such as methyl benzoate and ethyl benzoate; Carboxylic acid esters such as γ-butyrolactone, γ-valerolactone and δ-valerolactone; Phosphate esters such as trimethyl acid, ethyldimethyl phosphate, diethylmethyl phosphate, triethyl phosphate; nitriles such as acetonitrile, propionitrile, methoxypropionitrile, glutaronitrile, adiponitrile, 2-methylglutaronitrile Amides such as N-methylformamide, N-ethylformamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidinone, N-methylpyrrolidone, N-vinylpyrrolidone; dimethylsulfone, ethylmethylsulfone , Diechi Sulfur compounds such as sulfone, sulfolane, 3-methylsulfolane, 2,4 dimethylsulfolane: alcohols such as ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, Ethers such as 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, 2,6-dimethyltetrahydrofuran, tetrahydropyran; sulfoxides such as dimethyl sulfoxide, methylethyl sulfoxide, diethyl sulfoxide; benzonitrile, Aromatic nitriles such as tolunitrile; nitromethane, 1,3-dimethyl-2-imidazolidinone, 1,3-dimethyl-3, 4,5,6-tetrahydro-2 (1H) -pyrimidinone, 3-methyl-2-oxazolidinone and the like can be mentioned, and one or more of these are preferable. Among these, carbonate esters, aliphatic esters, and ethers are more preferable, and carbonates are more preferable.

The solvent may contain an ionic liquid. An ionic liquid consists of a compound comprised by a cation and anio, and can use 1 type (s) or 2 or more types. Such an ionic liquid is preferably a liquid having a constant volume at 40 ° C. and having fluidity, and specifically, a liquid having a viscosity of not more than 500 mPa · s at 40 ° C. is preferable. . The liquid is more preferably 200 mPa · s or less, and still more preferably 100 mPa · s.
Specific examples thereof include 1-ethyl-3-methylimidazolium trifluoromethanesulfonimide, 1-ethyl-3-methylimidazolium dicyanoamide, 1-ethyl-3-methylimidazolium tricyanomethide, diethyldimethoxytrifluoro. Examples include methanesulfonimide, diethyldimethoxydicyanoamide, diethyldimethoxytricyanomethide, 1-methyl-1-butyltrifluoromethanesulfonimide, 1-methyl-1-butyldicyanoamide, 1-methyl-1-butyltricyanomethide, etc. be able to.

The electrolyte using the lithium dicyanotriazolate is preferably used for a lithium battery.
The lithium battery is preferably composed of a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte using the lithium dicyanotriazolate of the present invention as basic components. Such a lithium secondary battery is preferably a non-aqueous electrolyte lithium secondary battery that is a lithium secondary battery other than the water electrolyte. For example, in the case of a lithium secondary battery using lithium metal as the negative electrode active material and V ₂ O ₅ as the positive electrode active material, a reaction of Li → Li ⁺ + e ⁻ occurs in the negative electrode during discharge, and lithium ions generated in the negative electrode (Li ⁺ ) conducts ions through the polymer electrolyte, and electrons (e ⁻ ) conduct to the external circuit and move to the surface of the positive electrode. On the surface of the positive electrode, V ₂ O ₅ + Li ⁺ + e ⁻ → LiV ₂ O ₅ reacts. Occurs, and a current flows from the positive electrode to the negative electrode. During charging, a reverse reaction occurs during discharging, and current flows from the negative electrode to the positive electrode. Thus, electricity can be stored or supplied by a chemical reaction by ions.

In the case of a lithium primary battery and a lithium polymer secondary battery, it is preferable to use metallic lithium as the negative electrode. When used as a lithium ion secondary battery, it is prepared by coating a negative electrode mixture containing a negative electrode active material, a negative electrode conductive agent, a negative electrode binder, etc. on the surface of the negative electrode current collector. Is preferred. The negative electrode mixture may contain various additives in addition to the conductive agent and the binder.
As the negative electrode active material, metallic lithium, a material capable of inserting and extracting lithium ions, and the like are suitable. Suitable materials that can occlude and release lithium ions include metallic lithium; pyrolytic carbon; coke such as pitch coke, needle coke, and petroleum coke; graphite; glassy carbon; phenol resin, furan resin, and the like. Organic polymer compound fired body fired at temperature and carbonized; carbon fiber; carbon material such as activated carbon; polymer such as polyacetylene, polypyrrole, polyacene; Li _4/3 Ti _5/3 O ₄ , TiS ₂ etc. Lithium-containing transition metal oxides or transition metal sulfides; metals such as Al, Pb, Sn, Bi, and Si that are alloyed with alkali metals; AlSb, Mg ₂ Si, in which alkali metals can be inserted between lattices, and cubic intermetallic compounds of NiSi _{2, etc., Li 3-f G f N} : lithium nitrogen compounds in (G transition metals), etc. Etc. are preferred. These can use 1 type (s) or 2 or more types. Among these, metallic lithium and carbon materials that can occlude / release alkali metal ions are more preferable.

The negative electrode conductive agent may be an electronic conductive material, such as natural graphite such as flake graphite, graphite such as artificial graphite; acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, etc. Carbon black; conductive fibers such as carbon fibers and metal fibers; metal powders such as carbon fluoride, copper and nickel; organic conductive materials such as polyphenylene derivatives are suitable. These can use 1 type (s) or 2 or more types.

The binder for the negative electrode may be either a thermoplastic resin or a thermosetting resin. Polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, styrene butadiene rubber, tetrafluoroethylene-hexafluoropropylene Polymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotri Fluoroethylene, vinylidene fluoride-pentafluoropropylene copolymer, propylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene -Tetrafluoroethylene copolymer, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, An ethylene-methyl methacrylate copolymer, polyamide, polyurethane, polyimide, polyvinyl pyrrolidone, and a copolymer thereof are preferable. These can use 1 type (s) or 2 or more types. Among these, styrene butadiene rubber, polyvinylidene fluoride, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, polyamide, polyurethane, More preferred are polyimide, polyvinylpyrrolidone and copolymers thereof.

The current collector for the negative electrode may be an electronic conductor that does not cause a chemical change inside the battery. Stainless steel, nickel, copper, titanium, carbon, conductive resin, carbon on the surface of copper or stainless steel, Those having nickel or titanium adhered or coated thereon are suitable. Among these, copper and alloys containing copper are more preferable. These can use 1 type (s) or 2 or more types. Further, the surface of the negative electrode current collector can be oxidized and used. Furthermore, it is desirable to make the current collector surface uneven. As the shape of the current collector for the negative electrode, a foil, a film, a sheet, a net, a punched one, a lath body, a porous body, a foamed body, a molded body of a fiber group, and the like are suitable. The thickness of the current collector is preferably 1 to 500 μm.

The positive electrode is preferably prepared by coating a positive electrode mixture containing a positive electrode active material, a positive electrode conductive agent, a positive electrode binder, and the like on the surface of the positive electrode current collector. The positive electrode mixture may contain various additives in addition to the conductive agent and the binder.
Examples of the positive electrode active _{material, Li x CoO 2, Li x} NiO 2, Li x MnO 2, Li x Co y Ni 1-y O 2, Li x Co y J 1-y O z, Li x Ni 1-y _{J y O z, Li x Mn} 2 O 4, Li x Mn 2-y J y O 4; MnO 2, V g O h, Cr g O h (g and h is an integer of 1 or more) of lithium such as An oxide or the like not containing is preferable. These can use 1 type (s) or 2 or more types.
J represents at least one element selected from Na, Mg, Sc, Y, Mn, Fe, Co, Ni, Cu, Zn, Al, Cr, Pb, Sb, and B. X is 0 ≦ x ≦ 1.2, y is 0 ≦ y ≦ 0.9, z is 2.0 ≦ z ≦ 2.3, and x is charge / discharge of the battery. Will increase or decrease. Further, as the positive electrode active material, a transition metal chalcogenide, vanadium oxide or niobium oxide which may contain lithium, an organic conductive material composed of a conjugated polymer, a chevrel phase compound, or the like may be used. The average particle diameter of the positive electrode active material particles is preferably 1 to 30 μm.

The positive electrode conductive agent may be any electron conductive material that does not cause a chemical change in the charge / discharge potential of the positive electrode active material used, and is the same as the negative electrode conductive agent described above; metal powder such as aluminum and silver Conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide are suitable. These can use 1 type (s) or 2 or more types. Among these, artificial graphite, acetylene black, and nickel powder are more preferable. The amount of the positive electrode conductive agent used is preferably 1 to 50 parts by weight, and more preferably 1 to 30 parts by weight with respect to 100 parts by weight of the positive electrode active material. When carbon black or graphite is used, the amount is preferably 2 to 15 parts by weight with respect to 100 parts by weight of the positive electrode active material.

The positive electrode binder may be either a thermoplastic resin or a thermosetting resin, other than the styrene butadiene rubber in the negative electrode binder described above, and tetrafluoroethylene-hexafluoroethylene copolymer. A coalescence or the like is preferred. These can use 1 type (s) or 2 or more types. Among these, polyvinylidene fluoride and polytetrafluoroethylene are more preferable.

The positive electrode current collector may be any electron conductor that does not cause a chemical change in the charge / discharge potential of the positive electrode active material to be used. The surface of stainless steel, aluminum, titanium, carbon, conductive resin, aluminum or stainless steel Those having carbon or titanium adhered or coated thereon are suitable. These can use 1 type (s) or 2 or more types. Among these, aluminum or an alloy containing aluminum is preferable. Further, the surface of the positive electrode current collector can be oxidized and used. Furthermore, it is desirable to make the current collector surface uneven. The shape and thickness of the positive electrode current collector are the same as those of the negative electrode current collector described above.

Examples of the shape of the lithium secondary battery include a coin shape, a button shape, a sheet shape, a laminated shape, a cylindrical shape, a flat shape, a square shape, and a large size used for an electric vehicle.
Electrochemical devices such as lithium secondary batteries using a polymer electrolyte containing lithium dicyanotriazolate can be suitably used for various applications such as portable information terminals and portable electronic devices.

The lithium dicyanotriazolate of the present invention has the above-described configuration, has high ionic conductivity, does not corrode the electrode, etc., and is stable over time, so that a lithium polymer that requires long-term reliability is required. It can be suitably applied to an electrolyte constituting an ion conductor of a battery having a charging and discharging mechanism such as a secondary battery.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Note that “%” means “mass%” unless otherwise specified.

Production Example 1
To a 2 L separable flask in which 400 g of water was weighed, 98 g (1 mol) of sulfuric acid and 216 g (2 mol) of diaminomaleonitrile were successively added, and the mixture was submerged with a paddle blade and placed in an ice bath while maintaining the internal temperature at 20 ° C. An aqueous solution prepared by dissolving 141.45 g (2.05 mol) of sodium nitrate in 410 g of water was added dropwise over 2 hours. After completion of the dropwise addition, stirring was continued for 30 minutes, and then the reaction solution was suction filtered with a 0.2 μm mixed cellulose filter, and the filtrate from which insoluble matter was removed was distilled off with a rotary evaporator until the reaction mixture was dried. From the obtained solid, 400 g of diisopropyl ether was added to extract dicyanotriazole. Further, 400 g of water was added to the diisopropyl ether phase to wash out impurities causing coloration, and then the solvent was removed from the diisopropyl ether solution of dicyanotriazole with a rotary evaporator to obtain Hazen 200 HDTA.

Production Example 2
The HDCTA obtained in Production Example 1 was sublimed under reduced pressure once at 50 ° C. and 30 Pa for 50 hours to obtain 100 g of purified Hazen 30 HDCTA.

Comparative production example 1
Non-patent document 1 (Egashila et al., 4 Lithium Dicyanotriazolate as a Lithium Salt for Poly (ethylene oxide) Based Polymer Electolytes) in a polymer electrolyte based on polyethylene oxide, HDCTA was synthesized according to the description of Electrochemical and Solid-State Letters, 2003, Vol. 6, No. 4, p.A71-A73).
21.6 g (200 mol) of diaminomaleonitrile, 20.9 g of 35% hydrochloric acid (HCl 200 mmol), and 236 g of water were weighed in a 500 mL separable flask and stirred with a paddle blade. This was put in dry ice-acetone cryogen and the internal temperature was kept at 0 ° C., and 13.8 g of sodium nitrite was added as a powder over 60 minutes. The reaction solution was subjected to suction filtration with a 0.2 μm mixed cellulose filter. The filtrate was extracted by adding 80 g of diethyl ether, and the diethyl ether phase was collected. This extraction operation was performed three times, and the diethyl ether phase was collected and dried on a rotary evaporator. The obtained solid was subjected to vacuum sublimation twice at 80 ° C. and 30 Pa for 150 hours to obtain Hazen 30 HDTA.

Example 1-1
100 g (0.84 mol) of HDCTA obtained in Production Example 2 was dissolved in 1000 g of water, and lithium carbonate was added little by little until the pH of the reaction solution reached 7 while stirring at room temperature. The reaction solution was suction filtered with a 0.2 μm mixed cellulose filter to remove dust and the like, and then the filtrate was dried to dryness with a rotary evaporator to obtain LiDCTA. 100 g of the obtained LiDCTA and 1000 g of toluene were weighed in a 2 L separable flask, and azeotropic dehydration was performed at 50 ° C. for 20 minutes and 130 ° C. for 100 minutes while refluxing toluene. This was suction filtered through a 0.2 μm PTFE filter, and the solid was dried at 140 ° C. under reduced pressure. The water content of this LiDCTA was 860 ppm, the excess acid amount was 0.05 × 10 ⁻³ mol / g, Hazen 5, and the amidated compound concentration was 0.20%.

Example 2-1
LiDCTA was obtained in the same manner as in Example 1-1 except that azeotropic dehydration was performed while distilling toluene without refluxing. The water content of this LiDCTA was 510 ppm, the excess acid amount was 0.05 × 10 ⁻³ mol / g, Hazen 7, and the amidated compound concentration was 0.19%.

Example 3-1.
After dissolving 20 g of LiDCTA obtained from Example 1-1 in 180 g of dehydrated acetonitrile (manufactured by Kanto Chemical Co., Ltd., water 25 ppm), the molecular sieve (Li-A manufactured by Union Showa Co., Ltd.) was dried with 2 g, and then 0.5 μm hydrophilic. Suction filtration with a neutral PTFE filter, the filtrate was dried on a rotary evaporator and then dried under reduced pressure. The water content was 170 ppm, the excess acid amount was 0.05 mmol / g, Hazen 160, Hazen 160, and the amidated compound concentration was 0.14%. there were.

Example 4-1
LiDCTA was obtained in the same manner as in Example 1-1 except that the addition of lithium carbonate was terminated when the pH reached 5 in an aqueous solution of 10 g of HDCTA obtained from Production Example 2. The water content of this LiDCTA was 450 ppm, the excess acid amount was 0.15 × 10 ⁻³ mol / g, Hazen 100, and the amidated compound concentration was 0.14%.

Example 5-1
LiDCTA was obtained in the same manner as in Example 1-1 except that the addition of lithium carbonate was terminated when the pH reached 9 in an aqueous solution of 10 g of HDCTA obtained from Production Example 2. The water content of this LiDCTA was 450 ppm, the excess base amount was 0.15 × 10 ⁻³ mol / g, Hazen 150, and the amidated compound concentration was 0.35%.

Comparative Example 1-1
10 g (84 mmol) of HDCTA obtained in Comparative Production Example 1 was dissolved in 100 g of acetonitrile, 3.5 g (47 mmol) of lithium carbonate was added, and the mixture was stirred and reacted at room temperature for 2 hours. In order to remove unreacted lithium carbonate from the reaction solution, suction filtration was performed with a 0.5 μm hydrophilic PTFE filter, and the filtrate was dried to dryness with a rotary evaporator to obtain LiDCTA. The obtained LiDCTA was dried under reduced pressure at 80 ° C. and 0.01 Pa.
This LiDCTA had a water content of 920 ppm, an excess acid content of 0.20 mmol / g, Hazen 5, and an amidated compound concentration of 0.18%.

Comparative Example 2-1
LiDCTA was obtained in the same manner as in Example 1-1 except that toluene azeotropic dehydration was performed at 50 ° C. for 20 minutes and 130 ° C. for 40 minutes. The water content of this LiDCTA was 1520 ppm, the excess acid amount was 0.05 × 10 ⁻³ mol / g, Hazen 7, and the amidated compound concentration was 0.19%.

Comparative Example 3-1
LiDCTA was obtained in the same manner as in Example 1-1, except that the addition of lithium carbonate was terminated when the pH reached 10 in an aqueous solution of 10 g of HDCTA obtained from Production Example 2. The water content of this LiDCTA was 450 ppm, the excess base amount was 0.20 × 10 ⁻³ mol / g, Hazen 140, and the amidated compound concentration was 0.18%.

Comparative Example 4-1
LiDCTA was obtained in the same manner as in Example 1-1 except that the time for toluene azeotropy was 50 ° C. × 20 minutes and 130 ° C. × 70 minutes. The water content of this LiDCTA was 1080 ppm, the excess acid amount was 0.05 × 10 ⁻³ mol / g, Hazen 6, and the amidated compound concentration was 0.20%.

Comparative Example 5-1
10 g (84 mmol) of HDCTA obtained in Comparative Production Example 1 was dissolved in 100 g of acetonitrile, 3.5 g (47 mmol) of lithium carbonate was added, and the mixture was stirred and reacted at room temperature for 2 hours. In order to remove unreacted lithium carbonate from the reaction solution, suction filtration was performed with a 0.5 μm hydrophilic PTFE filter to obtain a filtrate. The pH of the obtained filtrate was 7. This filtrate was dried with a rotary evaporator to obtain LiDCTA. 10 g of the obtained LiDCTA and 100 g of toluene were weighed in a 200 mL separable flask, and azeotropic dehydration was performed for 120 minutes while refluxing toluene at 130 ° C. This was suction filtered with a 0.2 μm PTFT filter, and the solid was dried under reduced pressure at 140 ° C.
The water content of this LiDCTA was 600 ppm, the excess acid amount was 0.21 mmol / g, Hazen 6, and the amidated compound concentration was 0.21%.

Reference Example 1-1
LiDCTA was obtained in the same manner as in Example 1-1 except that 10 g of HDCTA obtained from Production Example 1 was used. The water content of this LiDCTA was 700 ppm, the excess acid amount was 0.05 × 10 ⁻³ mol / g, and Hazen was 240.

Reference Example 2-1
LiDCTA was obtained in the same manner as in Example 1-1 except that the temperature of toluene azeotropy was 120 ° C. for 120 minutes. The water content of this LiDCTA was 980 ppm, the excess acid amount was 0.05 × 10 ⁻³ mol / g, Hazen 5, and the amidated compound concentration was 1.05%.

Reference Example 3-1
LiDCTA was obtained by the same operation as in Example 1-1, except that the azeotropic temperature of toluene was 170 ° C. for 120 minutes. This LiDCTA had a water content of 920 ppm, an excess acid amount of 0.06 × 10 ⁻³ mol / g, Hazen 4, and an amidated compound concentration of 3.01%.

(Reactivity evaluation with electrode)
A solution prepared by dissolving 3 g of LiDCTA in 30 g of battery acetonitrile was dropped on a lithium (Li) foil in an atmosphere in which the dew point was controlled to −60 ° C. or lower, allowed to stand for 3 minutes, and then thoroughly washed with battery acetonitrile. The state of the surface was observed after drying for 30 minutes, and the reactivity between the negative electrode (Li foil) and the LiDCTA acetonitrile solution was evaluated.

Example 1-2
When the reactivity evaluation test with the electrode was performed using LiDCTA described in Example 1-1, no change was observed on the surface of the Li foil.

Example 2-2
When the reactivity evaluation test with the electrode was performed using LiDCTA described in Example 2-1, no change was observed on the surface of the Li foil.

Example 3-2
When the reactivity evaluation test with an electrode was performed using LiDCTA described in Example 3-1, no change was observed on the surface of the Li foil.

Example 4-2
When the reactivity evaluation test with an electrode was performed using LiDCTA described in Example 4-1, no change was observed on the surface of the Li foil.

Example 5-2
When the reactivity evaluation test with the electrode was performed using LiDCTA described in Example 5-1, no change was observed on the surface of the Li foil.

Comparative Example 1-2
When the reactivity evaluation test with the electrode was performed using LiDCTA described in Comparative Example 1-1, the portion of the Li foil surface where the LiDCTA solution was hung was discolored black.

Comparative Example 2-2
When the reactivity evaluation test with the electrode was performed using LiDCTA described in Comparative Example 2-1, the portion of the Li foil surface coated with the LiDCTA solution was discolored black.

Comparative Example 3-2
When the reactivity evaluation test with the electrode was performed using LiDCTA described in Comparative Example 3-1, insoluble matter was precipitated on the surface of the Li foil.

Comparative Example 4-2
When the reactivity evaluation test with the electrode was performed using LiDCTA described in Comparative Example 4-1, the portion of the Li foil surface coated with the LiDCTA solution was discolored black.

Comparative Example 5-2
When the reactivity evaluation test with the electrode was performed using LiDCTA described in Comparative Example 5-1, the portion of the Li foil surface coated with the LiDCTA solution was discolored black.

Reference Example 1-2
When the reactivity evaluation test with an electrode was performed using LiDCTA described in Reference Example 1-1, no change was observed on the surface of the Li foil.

Reference Example 2-2
When the reactivity evaluation test with the electrode was performed using LiDCTA described in Reference Example 2-1, no change was observed on the surface of the Li foil.

Reference Example 3-2
When the reactivity evaluation test with the electrode was performed using LiDCTA described in Reference Example 3-1, no change was observed on the surface of the Li foil.

From the above, it was found that when LiDCTA in the present invention is used as an electrolyte constituting the ionic conductor of a battery, the battery has excellent charge / discharge characteristics and long-term reliability.

(Charge / discharge test)
(Production of cathode)
LiDCTA, V ₂ O ₅ , acetylene black and PEO (polyethylene oxide) were dissolved in acetonitrile and dispersed with a homomixer, and then fine dust was removed with a filter. The aluminum foil thus produced was applied at a film thickness of 300 μm and dried under reduced pressure at 60 ° C. for 30 minutes. This was pressed with a press at a pressure of 25 MPa for 5 minutes to form a cathode.

(Preparation of solid electrolyte (SPE))
LiDCTA, P (EO / AGE) (poly (ethylene oxide-allyl glycidyl ether) copolymer), Irggua 651 (2,2-dimethoxy-1,2-diphenylethane-1-one) is dissolved in acetonitrile, and magnetics is dissolved. The mixture was thoroughly stirred with a stirrer to make it uniform, insolubles were removed with a filter, and degassed under reduced pressure. The solution thus prepared was applied to a copper foil with a film thickness of 250 μm and dried under reduced pressure at 60 ° C. for 30 minutes. This was irradiated with ultraviolet rays to crosslink the polymer. The obtained film was further dried under reduced pressure at 60 ° C. overnight to obtain SPE.

(Create coin battery)
The cathode, SPE, and lithium foil prepared by the above method were punched into a circle with punches having a diameter of 12 mm, 16 mm, and 14 mm, respectively, and bonded together in the order of lithium foil, SPE, and cathode. This was sandwiched between two circular stainless steel plates with a diameter of 16 mm, and a spring-like spacer was placed on the positive electrode side and housed in a CR2032-type battery can, and it was caulked with a caulking machine to produce a coin battery.

(Charge / discharge test)
Using the created coin battery, a charge / discharge test was performed with a charge / discharge test apparatus (manufactured by Asuka Electronics Co., Ltd.).
The test conditions were a temperature of 60 ° C., a voltage range of 3.2 V to 2.2 V, and a current density of 6 mA / g for the first time for the run-in operation with respect to the weight of the positive electrode active material, and then a constant current charge at 20 mA / g. A discharge test was conducted. As an index for evaluating the presence / absence of film formation during the charge / discharge cycle as an evaluation of the cycle characteristics of the battery, the presence / absence of a decrease in discharge capacity at the 10th cycle and the resistance value between the electrodes were measured.

Example 1-3
Using the LiDCTA described in Example 1-1, three coin batteries were prepared according to the method described above, and a charge / discharge test was performed. As a result, good charge / discharge characteristics were exhibited.

Reference Example 1-3
Using the LiDCTA described in Reference Example 1-1, three coin batteries were prepared according to the above-described method, and a charge / discharge test was performed. As a result, a decrease in capacity and an increase in interelectrode resistance after the test were remarkable. It turned out that it cannot be used as a battery.

Reference Example 2-3
Using LiDCTA described in Reference Example 2-1, three coin batteries were prepared according to the method described above, and a charge / discharge test was performed. A slight decrease in the discharge capacity was observed, but between the electrodes after the test. Resistance hardly increased.

Reference Example 3-3
Using the LiDCTA described in Reference Example 3-1, three coin batteries were prepared according to the method described above, and a charge / discharge test was performed. As a result, the discharge capacity was slightly reduced and the interelectrode resistance was clearly increased after the test. As a result, it was found that the battery could not be used as a secondary battery.
The results are shown in Tables 1 and 2.

Claims (3)

Lithium dicyanotriazolate having a water content of lithium dicyanotriazolate of 1000 ppm or less and an excess acid amount or excess base amount of less than 0.2 × 10 ⁻³ mol / g. The lithium dicyanotriazolate according to claim 1, wherein the Hazen value of the lithium dicyanotriazolate is 200 or less. The lithium dicyanotriazolate according to claim 1 or 2, wherein the lithium dicyanotriazolate has an amidation content of 1.5% by mass or less.