JP4923661B2 - Method for producing non-aqueous electrolyte secondary battery - Google Patents

Description

  The present invention relates to a method for producing a nonaqueous electrolyte secondary battery characterized by an initial charging method for a nonaqueous electrolyte secondary battery (e.g., a lithium ion secondary battery), and more specifically, metallic foreign matter is mixed in the battery. Even so, the present invention relates to a method capable of producing a nonaqueous electrolyte secondary battery in which the occurrence of performance degradation due to a short circuit or the like is suppressed.

  With the spread of portable electronic devices such as portable personal computers and handy video cameras in recent years, non-aqueous electrolyte secondary batteries having high voltage and high energy density have been widely used as power sources. In addition, due to environmental problems, electric vehicles and hybrid vehicles using a part of electric power have been put into practical use.

  As an additive used for a nonaqueous electrolyte secondary battery, various compounds have been proposed for the purpose of improving safety. For example, Patent Documents 1 and 2 propose hindered amine compounds having a specific structure, and Patent Document 3 proposes a phenolic antioxidant, a phosphite antioxidant, and a sulfide antioxidant having a specific structure. Has been.

Patent Document 4 proposes that a polymer-type hindered amine compound in which a hindered amine structure is incorporated in (meth) acrylic acid ester is added to the positive electrode, the negative electrode, or the separator.
Japanese Patent Laid-Open No. 10-154531 Japanese Patent Laid-Open No. 2001-210365 Japanese Patent Laid-Open No. 10-247517 JP 2001-210314 A

  By the way, in the nonaqueous electrolyte secondary battery, there is a possibility that a short circuit may occur when a metal foreign object is mixed. For this reason, countermeasures against contamination by foreign matters are taken in the manufacturing process, but it has been difficult to completely eliminate foreign matters. For example, metallic foreign matter may enter the battery due to deterioration of the device used in the manufacturing process. In particular, it was difficult to completely remove metal foreign matters (equivalent to φ40 μm) such as Fe and Cu of 0.3 μg or less.

  The cause of the short circuit due to the contamination of the metal foreign material is that the metal foreign material mixed in the positive electrode is dissolved by the electric potential, the metal ions eluted in the electrolyte are reduced and deposited on the negative electrode surface, and the metal proceeds from the negative electrode to the positive electrode. Because.

  Although the additive of the prior art shows a stabilizing effect, it is not satisfactory in solving the problem of the metal foreign matter, and it is not satisfactory because it is eluted into the electrolytic solution to lower the battery performance.

  The present invention has been completed in view of the above circumstances, and solves the problem of providing a method for manufacturing a non-aqueous electrolyte secondary battery that does not deteriorate battery performance even if metallic foreign matter is mixed in the battery. It should be a challenge.

  In order to solve the above problems, the present inventors have conducted intensive research. For example, it has been proposed to add an amide compound having a specific structure to an electrolyte as an additive for capturing metal ions eluted into the electrolyte and preventing a short circuit (Japanese Patent Application No. 2005-242957).

  However, since this amide compound (chelate compound) has a limited amount of dissolution in the electrolytic solution, it has been difficult to completely cope with the elution of metallic foreign matters in the battery. That is, the elution of the metallic foreign matter mixed into the battery due to the potential is local, and it is difficult to sufficiently supplement the concentration of the amide compound dissolved in the electrolytic solution. Therefore, under normal charging conditions, the eluted metal reaches the negative electrode before being captured by the chelate compound, so that the precipitation proceeds, and satisfactory battery performance cannot be fully realized.

As a result of intensive studies, the present inventors have discovered an effective method of using a chelate compound. In other words, by setting the conditions for the first charge after the battery is assembled as a predetermined condition, it was possible to reliably supplement the eluted metal and make it harmless. The present invention has been completed based on this finding, and comprises a non-aqueous electrolyte comprising an electrode body and an electrolyte composition containing a chelate compound that is 3- (N-salicyloyl) amino-1,2,4-triazole. The present invention is applied to a method for manufacturing a secondary battery.

  The method for producing a non-aqueous electrolyte secondary battery according to the present invention is a condition satisfying the relational expression (1) and / or the relational expression (2) at the time of charging in the first cycle after immersing the electrode body in the electrolyte composition. It has the conditioning process performed by this.

Here, the relational expression (1) is ct / V ≧ 1.08 × 10 ⁻³ (wherein c is the concentration of the chelate compound in the electrolyte (mol / dm ³ ); t is lithium) The cumulative time (h) that satisfies the elution condition in which the positive electrode potential is 3.5 V or more and less than or equal to the positive electrode potential in a fully charged state, V is the average potential (V) of the positive electrode under the elution condition; c is 0.004 (mol / dm ³ ) or more; t is 0.75 (h) or more; V is 3.5 ≦ V ≦ 3.8. Then, the equation (2), in I / c <38 (Equation (2), the concentration of an electrolytic solution (mol / dm ³ of c of the chelating compound); I is at one cycle charge Current value (C) (1C is a current value for discharging the battery capacity in 1 hour); c is 0.004 (mol / dm ³ ) or more, and I is 0.20 (C) or less) .

  Relational expression (1) prescribes a condition that can sufficiently capture the eluted metal by passing it as slowly as possible through the range of 3.5 V or more, which is the positive electrode potential at which the metal begins to elute. If the positive electrode potential is too high, the metal elution rate increases, so the positive electrode potential is further limited to 3.8 V or less. Relational expression (1) indicates that the concentration of the chelate compound is increased, the passage time (cumulative time) is increased, and the average voltage is decreased within this voltage range.

  The relational expression (2) defines a condition that can suppress the metal elution rate within a range that can be supplemented by controlling the charging current below a predetermined value. According to the relational expression (2), the upper limit of the magnitude of the charging current is defined in inverse proportion to the chelate compound concentration.

  The electrolyte composition preferably contains one or more organic solvents selected from the group of non-aqueous solvents consisting of carbonates, lactones, ethers, sulfolanes, and dioxolanes.

  In particular, it is desirable that the electrolyte composition contains at least one cyclic carbonate compound and a chain carbonate compound. Specifically, the cyclic carbonate compound is at least one of ethylene carbonate and 1,2-butylene carbonate, and the chain carbonate compound is selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate. One or more compounds are desirable.

  Since the manufacturing method of the nonaqueous electrolyte secondary battery of the present invention has the above-described configuration, the following effects are exhibited. That is, even if a metal foreign matter is mixed in the non-aqueous electrolyte, the metal foreign matter can be eluted and can be kept in a stable state in the solution through the conditioning process. Therefore, it is possible to effectively prevent the occurrence of a short circuit due to the metal foreign object.

The method for producing a nonaqueous electrolyte secondary battery of the present invention will be described in detail based on the following embodiments. The non-aqueous electrolyte secondary nonaqueous electrolyte secondary battery manufacturing method can be applied in the battery of the present embodiment is a battery that reaches more than 3.5V as a reference positive electrode potential a negative electrode (lithium), 3- (N -Salicyloyl) Any battery having an electrolyte composition containing a chelate compound that is amino-1,2,4-triazole is not particularly limited, and cobalt oxide, nickel oxide, manganese oxide, etc. are used as the positive electrode active material. The adopted lithium secondary battery can be exemplified.

The addition amount of the chelate compound in the non-aqueous electrolyte secondary battery to which the manufacturing method of this embodiment can be applied is 0.001 (mol / dm ³ ) or more and 0.1 (mol) in terms of mass ratio with respect to the non-aqueous electrolyte. / Dm ³ ) or less, preferably 0.004 (mol / dm ³ ) or more and 0.02 (mol / dm ³ ) or less. When the amount of the chelate compound added is 0.001 (mol / dm ³ ) or more, a sufficient effect is obtained, and when the amount is 0.1 (mol / dm ³ ) or less, the charge / discharge characteristics of the battery can be improved.

  As the other configuration of the nonaqueous electrolyte secondary battery to which the present embodiment can be applied, the configuration of a general nonaqueous electrolyte secondary battery can be adopted. For example, it has an electrode body, an electrolyte composition, and a battery case that houses them. The electrode body is composed of a positive electrode, a negative electrode, and a separator. Each of the positive electrode, the negative electrode, and the separator is a sheet-like member, and the positive electrode and the negative electrode are stacked and wound via the separator.

As the positive electrode, a slurry obtained by applying a slurry of a positive electrode active material, a binder and a conductive material to a current collector and drying it into a sheet is used. Examples of the positive electrode active material include TiS ₂ , TiS ₃ , MoS ₃ , FeS ₂ , Li _(1-x) MnO ₂ , Li _(1-x) Mn ₂ O 4, Li _(1-x) CoO ₂ , Li _{(1- x) NiO 2, LiV 2 O} 3, V 2 O 5 and the like. In addition, X in these positive electrode active materials shows the number of 0-1. A material obtained by adding or substituting a transition metal such as Li, Mg, Al, or Co, Ti, Nb, or Cr may be used. Moreover, not only these lithium-metal composite oxides are used alone, but also a plurality of them can be mixed and used. Among these, the lithium-metal composite oxide is preferably at least one of a lithium manganese-containing composite oxide having a layered structure or a spinel structure, a lithium nickel-containing composite oxide, and a lithium cobalt-containing composite oxide. Examples of the binder include, but are not limited to, polyvinylidene fluoride (PVDF), EPDM, SBR, NBR, and fluororubber.

  Examples of the conductive material for the positive electrode include graphite fine particles, acetylene black, ketjen black, carbon black such as carbon nanofiber, and amorphous carbon fine particles such as needle coke, but are not limited thereto.

  As the solvent for forming a slurry, an organic solvent that dissolves the binder is usually used. For example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, NN-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran, and the like can be mentioned. Not. In some cases, the active material is slurried with PTFE or the like by adding a dispersant, a thickener or the like to water.

  As the negative electrode, a negative electrode active material and a binder that are slurried with a solvent are applied to a current collector and dried to form a sheet. The negative electrode active material may be lithium or a lithium alloy, but is preferably a carbon material that can occlude and release lithium ions with higher safety. The carbon material is not particularly limited, but graphite, petroleum-based coke, coal-based coke, petroleum-based pitch carbide, coal-based pitch carbide, carbonized resin such as phenol resin / crystalline cellulose, etc. and partially carbonized carbon. Examples thereof include materials, furnace black, acetylene black, pitch-based carbon fibers, and PAN-based carbon fibers. As the solvent for forming a slurry, an organic solvent that dissolves the binder is usually used. For example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, N, N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran and the like can be mentioned. Not. In some cases, the active material is slurried with a latex such as SBR by adding a dispersant, a thickener or the like to water. Examples of the binder include the same binder as that for the positive electrode.

  Copper, nickel, stainless steel, nickel-plated steel or the like is usually used for the current collector of the negative electrode, and aluminum, stainless steel, nickel-plated steel or the like is usually used for the current collector of the positive electrode.

  As the separator used in the present embodiment, a commonly used polymer microporous film can be used without any particular limitation. For example, polyethylene, polypropylene, polyvinylidene fluoride, polyvinylidene chloride, polyacrylonitrile, polyacrylamide, polytetrafluoroethylene, polysulfone, polyethersulfone, polycarbonate, polyamide, polyimide, polyethers such as polyethylene oxide and polypropylene oxide, carboxymethylcellulose And various celluloses such as hydroxypropyl cellulose, polymer compounds mainly composed of poly (meth) acrylic acid and various esters thereof, derivatives thereof, and films made of copolymers or mixtures thereof. Moreover, such a film may be used independently and the multilayer film which overlap | superposed these films may be sufficient. Furthermore, various additives may be used for these films, and the kind and content thereof are not particularly limited. Among these microporous films, polyethylene, polypropylene, polyvinylidene fluoride, and polysulfone are preferably used for the nonaqueous electrolyte secondary battery of the present embodiment.

  These separator films are microporous so that the electrolyte can penetrate and ions can easily pass therethrough. The microporosity method includes a phase separation method in which a polymer compound and a solvent solution are formed into a film while microphase separation is performed, and the solvent is extracted and removed to make it porous. The film is heat-treated after extrusion, and the crystals are aligned in one direction, and further, the stretching method is used to form a gap between the crystals by stretching to achieve porosity, which is appropriately selected depending on the polymer film used. The

  The electrolyte composition used in this embodiment can be exemplified by an electrolyte dissolved in a solvent. Solvents include high dielectric constant solvents, cyclic carbonates such as propylene carbonate, ethylene carbonate, butylene carbonate, vinylene carbonate, cyclic esters such as γ-butyrolactone, γ-valerolactone, tetramethylsulfolane, dimethyl sulfoxide, N -Methylpyrrolidone, dimethylformamide and derivatives thereof are not particularly limited.

  Examples of the low-viscosity solvent include chain carbonates such as dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate, chain ethers such as dimethoxyethane, ethoxymethoxyethane, and diethoxyethane, cyclic ethers such as tetrahydrofuran, dioxolane, and dioxane, methyl formate, Chain esters such as ethyl formate, methyl acetate, ethyl acetate, methyl propionate and ethyl propionate, acetonitrile, propionitrile, nitromethane and derivatives thereof are used, but are not particularly limited.

  In the nonaqueous electrolyte secondary battery of the present embodiment, the electrolyte composition is selected from the group of nonaqueous solvents consisting of carbonates, lactones, ethers, sulfolanes and dioxolanes among these organic solvents. It is preferable that at least one of the above cyclic carbonates and at least one of the above chain carbonates are contained. The cyclic carbonate is one or more selected from the group consisting of ethylene carbonate and 1,2-butylene carbonate, and the chain carbonate is selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate. Most preferably, it is at least one selected.

  The cyclic carbonate and the chain carbonate are preferably used in a mass ratio of 10:90 to 90:10.

As the electrolyte, a conventionally known electrolyte is used. For example, LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiSbF ₆ , LiSiF ₅ , LiAlF ₄ , LiSCN, LiClO ₄ , LiCl, LiF, LiBr, LiAlF _{4 and the} like.

  The manufacturing method of the nonaqueous electrolyte secondary battery of the present embodiment is characterized by a conditioning process performed at the time of charging in the first cycle after the nonaqueous electrolyte secondary battery is assembled by a general method that is not particularly limited. Charging in the first cycle is charging performed first after the above-described electrode body is immersed in the above-described electrolyte composition.

  The conditioning process is performed under conditions that satisfy the relational expression (1) or the relational expression (2).

The relational expression (1) is expressed by ct / V ≧ 1.08 × 10 ⁻³ . The value of ct / V is preferably 1.10 × 10 ⁻³ or more, and more preferably 1.30 × 10 ⁻³ or more.

In formula (1), c is the concentration (mol / dm ³ ) of the chelate compound in the electrolytic solution, and is preferably 0.004 (mol / dm ³ ) or more, and 0.0053 (mol / dm ^3). ) Or more.

  t is the cumulative time (h) that satisfies the elution condition in which the positive electrode potential is 3.5 V or more and the positive electrode potential or less in a fully charged state with respect to lithium. This cumulative time is the cumulative time of the time when the positive electrode potential became 3.5 V or more and the positive electrode potential was below the full potential state during charging. t is 0.75 (h) or more, preferably 1.0 (h) or more, more preferably 1.25 (h) or more. Here, the positive electrode potential in the fully charged state as the upper limit of the positive electrode potential, which is a reference for determining t, varies depending on the applied nonaqueous electrolyte secondary battery, but the positive electrode active material includes lithium and a transition metal. A value of about 4.1 V or 4.2 V can be adopted in a general lithium secondary battery employing the composite oxide of In addition, the upper limit value is set to a lower potential, for example, 4.0 V, 3.9 V, 3.8 V, 3.7 V, etc., so that the elution metal can be captured more effectively although the productivity is lowered. It can also be adopted.

  Here, during normal charging, the positive electrode potential is usually maintained at a certain value or gradually increased from the lower side, but a high voltage is applied in a pulsed manner or the positive electrode potential is changed. In the case of employing a special process such as, a special fluctuation such as once returning to less than 3.5 V after the positive electrode potential becomes 3.5 V or more may be observed. Even in such a case, t is a time obtained by accumulating the time when charging is continued and the positive electrode potential is in the voltage range described above. The elution of metallic foreign matter proceeds while the positive electrode potential is 3.5 V or more, and when it returns to less than 3.5 V, the elution of metallic foreign matter is interrupted, so only the time when it exceeds 3.5 V is accumulated. T is calculated.

  It is assumed that the positive electrode potential fluctuates to a potential equal to or higher than the potential corresponding to the positive electrode potential in a fully charged state by applying a high voltage in a pulsed manner. If it is instantaneous (for example, about several seconds to several tens of seconds), t is a time obtained by accumulating the time when charging is continued and the positive electrode potential is in the voltage range described above. When a voltage exceeding the positive electrode potential in a fully charged state is reached, the elution of the metal foreign matter may become very fast, and there is a risk that the elution of the eluted metal by the chelate compound may not be in time. This is because the influence is small.

  V is the average potential (V) of the positive electrode under the elution conditions used when calculating t. This V is 3.5V or more and 3.8V or less. The dissolution potential of Fe assumed to be mixed here is 3.25 V, and the dissolution potential of Cu is 3.45 V. Therefore, as the value of V, it is desirable to adopt a value that exceeds these dissolution potentials and is as close to these dissolution potentials as possible, and V is desirably as low as possible. For example, values of 3.7V or less, 3.6V or less, and 3.5V can be adopted.

-Relational expression (2) is represented by I / c <38. More preferably, the value of I / c is 34 or less. Wherein (2), c is the concentration (mol / dm ³⁾ in an electrolytic solution of the chelating compound, preferably set to 0.004 (mol / dm ³⁾ or more, 0.0053 (mol / dm ³ ) It is more desirable to set it above.

  I represents a current value (C) at the time of charging in the first cycle (1C is a current value for discharging the battery capacity in one hour) and is 0.20 (C) or less. The value is preferably 0.167 (C) or less, and values such as 1.5 (C) or less and 0.10 (C) or less can also be adopted. A smaller value of I is desirable, but from the viewpoint of improving productivity, it is desirable to set it to 0.10 (C) or more.

  The method for producing a nonaqueous electrolyte secondary battery of the present invention will be described in detail below based on examples. However, it goes without saying that the present invention is not limited by the following examples.

(Test 1)
[Example 1]
A lithium secondary battery was produced according to the following procedure.

(Preparation of positive electrode)
85 parts by mass of LiNi _0.8 Co _0.17 Al _0.03 O ₂ as a positive electrode active material, 10 parts by mass of acetylene black as a conductive material, and 5 polyvinylidene fluoride (PVDF) as a binder The positive electrode material was obtained by mixing the mass part. This positive electrode material was dispersed in N-methyl-2-pyrrolidone (NMP) to form a slurry. This slurry was applied to both surfaces of a positive electrode current collector made of aluminum, dried, and press-molded to obtain a positive electrode plate. Then, this positive electrode plate was cut into a predetermined size, and a sheet-like positive electrode was produced by scraping off the electrode composite material at the portion to be a lead tab weld for extracting current.

(Preparation of negative electrode)
92.5 parts by mass of the carbon material powder as the negative electrode active material and 7.5 parts by mass of PVDF as the binder were mixed to obtain a negative electrode material. This negative electrode material was dispersed in NMP to form a slurry. This slurry was applied to both sides of a copper negative electrode current collector, dried and press-molded to obtain a negative electrode plate. Then, this negative electrode plate was cut into a predetermined size, and a sheet-like negative electrode was produced by scraping off a portion of the electrode mixture to be a lead tab weld for extracting current.

(Preparation of non-aqueous electrolyte)
LiPF ₆ is dissolved in a mixed solvent of ethylene carbonate and diethyl carbonate in a volume ratio of 1: 1 so as to be 1 mol / dm ^3, and 3- (N-salicyloyl) amino-1, which is (Compound 3) as a chelate compound, is dissolved therein. 2,4-Triazole was added to a concentration of 0.004 mol / dm ³ to obtain an electrolyte composition.

(Assembly of lithium secondary battery)
The sheet-like positive electrode and the sheet-like negative electrode obtained above were wound in a state through a film made of microporous polyethylene having a thickness of 25 μm. At this time, 0.3 μg of Cu powder was placed on the positive electrode as a metal foreign matter and wound together to form a wound electrode body. The obtained wound electrode body was inserted into the case and held in the case. At this time, the current collecting lead having one end welded to the lead tab weld portion of the sheet-like positive electrode and the sheet-like negative electrode was joined to the positive electrode terminal or the negative electrode terminal of the case. Thereafter, 5.0 mL of the electrolyte composition was injected into the case holding the wound electrode body, and the case was hermetically sealed. By the above procedure, a cylindrical lithium secondary battery having a diameter of 18 mm and an axial length of 65 mm was manufactured.

(Initial charge)
The first cycle charging of the manufactured lithium secondary battery was performed under the following conditions. First, with a current value equivalent to a charging current of 0.25 C (1 C is a current value at which the battery capacity is discharged in 1 hour), the positive electrode potential is constant-current charged to 3.5 V with respect to the lithium reference, and at 3.5 V for 1.0 hour The constant potential was maintained, and then constant current charging was performed again at a charging current of 0.25 C until the battery voltage was 4.1 V. This initial charging was performed in an atmosphere at 20 ° C. For the positive electrode potential, lithium metal was inserted into the battery as a reference electrode, and it was confirmed whether the positive electrode potential during charging was regulated.

(Performance evaluation)
After the completion of charging in the first cycle, the battery was stored at 20 ° C. for 48 hours while being charged, and the voltage drop at that time was measured. Evaluation was performed by setting the amount of voltage drop from the battery voltage during initial charging as ΔV. This initial charging method with a small ΔV can effectively capture the eluted metal, and the battery performance can be maintained even if foreign metal is mixed in the battery. Considering the practical level, a voltage drop amount of 30 mV or less was determined to be a non-defective product, and if it was greater than 30 mV, it was determined as a defective product.

[Example 2]
A battery manufactured in the same manner as in Example 1 was used. Charging in the first cycle is a constant current charging to a positive electrode potential of 3.5V with respect to the lithium reference at a current value equivalent to a charging current of 0.25C (1C is a current value for discharging the battery capacity in 1 hour) to 3.6V. The constant potential was maintained for 1.0 hour.

[Example 3] and [Comparative Examples 1 and 2]
A battery manufactured in the same manner as in Example 1 was used. The charging conditions were as shown in Table 1.

Example 4
To the electrolyte composition, 3- (N-salicyloyl) amino-1,2,4-triazole of (Compound 3) as a chelate compound was added to a concentration of 0.0053 mol / dm ³ . Others were made in the same manner as the battery of Example 1. In the first cycle charging, the positive electrode potential was constant current charged to 3.5 V with respect to the lithium reference at a current value corresponding to a charging current of 0.25 C, and the constant potential was maintained at 3.5 V for 1.0 hour.

[Examples 5 to 7] and [Comparative Examples 3 and 4]
A battery manufactured in the same manner as in Example 4 was used. The charging conditions were as shown in Table 1.

Example 8
A battery manufactured in the same manner as in Example 4 was used. Charging in the first cycle is a constant current charging to a positive electrode potential of 3.6V with respect to the lithium reference at a current value equivalent to a charging current of 0.25C (1C is a current value for discharging the battery capacity in one hour) to 3.6V. At 0.75 hours.

[Examples 9 to 11] and [Comparative Example 5]
A battery manufactured in the same manner as in Example 4 was used. The charging conditions were as shown in Table 1.

〔result〕
Table 1 shows the initial charge method in the first cycle, the ct / V value, and the voltage drop ΔV 48 hours after the charge.

  As can be seen from the table, the voltage drop amount ΔV of the batteries of the respective examples in which the charge in the first cycle was performed while satisfying the relational expression (1) was small. This is considered to be a result of effectively capturing the eluted metal ions by the chelate compound by keeping the potential of the positive electrode at a potential close to the dissolution potential of the metal and suppressing rapid metal elution.

(Test 2)
Example 12
LiPF ₆ is dissolved in a mixed solvent of ethylene carbonate and diethyl carbonate in a volume ratio of 1: 1 so as to be 1 mol / dm ^3, and 3- (N-salicyloyl) amino-1, which is (Compound 3) as a chelate compound, is dissolved therein. 2,4-Triazole was added to a concentration of 0.0053 mol / dm ³ to obtain an electrolyte composition. Other batteries were prepared in the same manner as in Example 1. In the first cycle charging, constant current charging was performed until the battery voltage was 4.1 V with a current value corresponding to a charging current of 0.1 C.

[Examples 13 to 15] and [Comparative Example 6]
A battery manufactured in the same manner as in Example 12 was used. The charging conditions were as shown in Table 2.

Example 16
A battery manufactured in the same manner as in Example 12 was used. In the first cycle charging, constant current charging was performed until the battery voltage was 4.1 V at a current value corresponding to a charging current of 0.167C.

[Example 17] and [Comparative Example 7]
(Compound 3) 3- (N-salicyloyl) amino-1,2,4-triazole was added so as to be 0.0045 mol / dm ³ (Example 17) and 0.004 mol / dm ³ (Comparative Example 7). A battery produced in the same manner as in Example 12 was used except that the electrolyte was used. The charging conditions were as shown in Table 2.

〔result〕
Table 2 shows the initial charge method in the first cycle, the I / c value, and the voltage drop ΔV 48 hours after the charge.

  As can be seen from the table, the voltage drop amount ΔV of the battery of each Example performed while satisfying the relational expression (2) at the time of charging in the first cycle was small. This is considered to be a result of effectively capturing the eluted metal ions by the chelate compound by keeping the potential of the positive electrode at a potential close to the dissolution potential of the metal and suppressing rapid metal elution.

  As is clear from the results of Tables 1 and 2, the production of a non-aqueous electrolyte secondary battery that employs a conditioning process for charging in the first cycle while satisfying the relational expression (1) and / or (2) It has become clear that the method can prevent a short circuit failure even if a metal foreign object is mixed in the battery.

Claims (5)

A method for producing a non-aqueous electrolyte secondary battery comprising an electrode body and an electrolyte composition containing a chelate compound that is 3- (N-salicyloyl) amino-1,2,4-triazole ,
At the time of charging in the first cycle after immersing the electrode body in the electrolyte composition, relational expression (1): ct / V ≧ 1.08 × 10 ⁻³ (where c is in the electrolyte) Concentration of the chelate compound (mol / dm ³ ); t is a cumulative time (h) that satisfies the elution condition in which the positive electrode potential is 3.5 V or more and the positive electrode potential or less in a fully charged state with respect to lithium. V is the average potential (V) of the positive electrode under the elution conditions; c is 0.004 (mol / dm ³ ) or more; t is 0.75 (h) or more; V is 3.5 ≦ V ≦ 3.8. A method for producing a non-aqueous electrolyte secondary battery, comprising a conditioning step performed under conditions satisfying A method for producing a non-aqueous electrolyte secondary battery comprising an electrode body and an electrolyte composition containing a chelate compound that is 3- (N-salicyloyl) amino-1,2,4-triazole ,
At the time of charging in the first cycle after immersing the electrode body in the electrolyte composition, relational expression (2): I / c <38 (in the expression (2), c is the amount of the chelate compound in the electrolytic solution ) Concentration (mol / dm ³ ); I represents a current value (C) at the time of charging in the first cycle (1C represents a current value at which the battery capacity is discharged in 1 hour); c represents 0.004 (mol / dm ³⁾ The method for producing a non-aqueous electrolyte secondary battery includes a conditioning step performed under a condition that satisfies I) is 0.20 (C) or less. The nonaqueous electrolyte according to claim 1 or 2 , wherein the electrolyte composition contains one or more organic solvents selected from the group of nonaqueous solvents consisting of carbonates, lactones, ethers, sulfolanes, and dioxolanes. A method for manufacturing a secondary battery. The electrolyte composition, method of manufacturing a nonaqueous electrolyte secondary battery according to any of claims 1 to 3 which contains at least one kind of a cyclic carbonate compound and linear carbonate compound, respectively. The cyclic carbonate compound is at least one of ethylene carbonate and 1,2-butylene carbonate, and the chain carbonate compound is at least one selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate. The method for producing a nonaqueous electrolyte secondary battery according to claim 4 , which is a compound.