JP4415800B2 - Gel electrolyte and gel electrolyte battery - Google Patents

Description

  The present invention relates to a gel electrolyte used in place of a non-aqueous electrolyte in a lithium secondary battery or the like, and a gel electrolyte battery using the gel electrolyte.

  A positive electrode made of a lithium-containing compound, a negative electrode made of a material capable of occluding lithium, such as lithium, lithium alloys, and carbonaceous materials, and a non-aqueous electrolyte solution obtained by dissolving an electrolyte salt in a non-aqueous solvent Rechargeable lithium secondary batteries are attracting attention because they have higher output and higher energy density than aqueous secondary batteries such as lead batteries and nickel-cadmium batteries.

  In order to further improve the battery performance of such a lithium secondary battery, the selection of the negative electrode material and the positive electrode material is also important, but the characteristics of the electrolyte solution that conducts ions between the two electrodes greatly affect the battery performance. Come on. For this reason, many non-aqueous solvents and electrolyte salts have been proposed in order to obtain electrolytic solutions that have high ionic conductivity and can withstand high voltages.

  For example, as non-aqueous solvents, γ-butyl lactone, 1,2-dimethoxyethane, methyl propionate, butyl propionate, etc. are used in addition to carbonate solvents such as propylene carbonate, ethylene carbonate, methyl ethyl carbonate, dimethyl carbonate, etc. Has been.

Further, the electrolyte _{salt, LiPF6, LiClO 4, LiBF 4} , LiCF 3 SO 3, LiAsF 6, LiN (CF 3 SO 2) 2, LiC (CF 2 SO 2) 3 and the like have been reported.

  The non-aqueous electrolyte solution composed of the non-aqueous solvent and the electrolyte salt listed above has a relatively small heat capacity as described in JP-A-4-184870 (Patent Document 1). For this reason, when a battery is thrown into fire, for example, the solvent volatilizes with an increase in ambient temperature, and there is a risk of ignition.

  Therefore, Patent Document 1 proposes to add a phosphoric acid ester having flame retardancy to the electrolyte as a technique for preventing such ignition.

JP-A-4-184870

  By the way, organic ester compounds such as phosphate esters have a problem that their electrochemical redox resistance is relatively small. When such a phosphoric acid ester is applied to a lithium secondary battery having a high terminal voltage, for example, 4 V or more, an oxidation-reduction reaction of the phosphoric acid ester occurs with charge and discharge, resulting in deterioration of discharge capacity. Cause.

  Therefore, the present invention has been proposed in view of such a conventional situation, a gel electrolyte that is excellent in flame retardancy and electrochemical redox resistance, and can be used as an electrolyte material for a battery, and the gel electrolyte. It aims at providing the used battery.

The gel electrolyte according to the present invention proposed to achieve the above-described object includes a nonaqueous electrolytic solution in which an electrolyte salt containing at least LiPF ₆ is dissolved in a nonaqueous solvent, and a polyacrylonitrile or acrylonitrile-based co-polymer. The content of the acrylonitrile monomer in the non-aqueous solvent and the polyacrylonitrile or acrylonitrile-based copolymer is 5 mol% or more and 30 mol% or less, has flame retardancy, and is at an environment of 25 ° C. The ion conductivity is 1 mS / cm or more, and the battery according to the present invention uses this gel electrolyte.

  When a non-aqueous electrolyte having a specific composition is gelled by a polymer having a nitrile group in the side chain, for example, a flame retardant that exhibits a high ion conductivity of 1 mS / cm or more in an environment at a temperature of 25 ° C. A gel electrolyte is obtained.

  Such a gel electrolyte has an ionic conductivity of 1 mS / cm or more and does not contain a substance having poor redox resistance, such as a phosphate ester, and therefore can be used as an electrolyte material for a battery. When this gel electrolyte is used as an electrolyte material for a battery, it has flame retardancy, and thus a battery having excellent safety that does not ignite even when thrown into a fire is realized. Further, a battery using a gel electrolyte as an electrolyte material has an advantage that the electrolytic device does not leak to the outside no matter how it is handled, so that peripheral devices and the like are not contaminated.

  In such a gel electrolyte, for example, the gelling agent is gelled by a polymer having a nitrile group in the side chain.

  That is, in order to perform gelation with a polymer having a nitrile group in the side chain, a nonaqueous electrolytic solution in which a predetermined amount of electrolyte salt is dissolved is heated in advance, and a polymer having a nitrile group is added thereto as a gelling agent. To do. When a gelling agent is added to a non-aqueous solvent, the viscosity of the solution increases. And after this gelling agent melt | dissolves completely, the obtained gel solution is rapidly expand | deployed on a base | substrate and a gel electrolyte is obtained by cooling slowly.

  As the polymer used as the gelling agent, polyacrylonitrile is preferable from the viewpoint of gelation and flame retardancy, and in addition, a copolymer obtained by copolymerizing acrylonitrile monomer and other monomer species in an appropriate ratio. You can use coalescing. This acrylonitrile copolymer includes acrylonitrile / butadiene rubber, acrylonitrile / butadiene / styrene resin, acrylonitrile / polyethylene chloride / styrene resin, acrylonitrile / styrene resin, acrylonitrile / ethylene / propylene / diene / styrene resin, acrylonitrile / vinyl chloride resin. And acrylonitrile / methacrylate resin.

  Here, the degree of gelation by these polyacrylonitrile and acrylonitrile-based copolymer is determined by the molecular weight. Therefore. The polyacrylonitrile or acrylonitrile-based copolymer is required to have a molecular weight enough to cause gelation. However, when the molecular weight is extremely large, when added to the non-aqueous electrolyte, the solution viscosity becomes too high, and development and film formation become difficult. In view of this, it is preferable to use a polyacrylonitrile or acrylonitrile copolymer having a number average molecular weight of about 50,000 to 500,000.

  On the other hand, as the non-aqueous solvent and electrolyte salt used for the gel electrolyte, those usually used in lithium secondary batteries can be used.

  As the non-aqueous solvent, one having a potential window in the range of −0.3 V to 4.9 V with respect to the lithium potential is used. In particular, ethylene carbonate (EC), propylene carbonate (PC), γ-butyl lactone and the like are preferable because the potential window is in the above range and high ionic conductivity can be imparted to the gel electrolyte. These nonaqueous solvents may be used alone or in combination of two or more. For example, a mixed solvent in which EC and PC are combined is particularly preferable as a nonaqueous solvent for the gel electrolyte.

In addition, LiPF ₆ contained in the electrolyte salt is excellent in terms of ion conductivity and is very effective for imparting flame retardancy to the gel. As the electrolyte salt, a mixture of LiPF ₆ and another lithium salt can be used, but it is preferable to use LiPF ₆ alone.

  The optimum composition ratio of these materials is set from the viewpoints of film forming properties and gelation during production, in addition to ion conductivity and flame retardancy. Specifically, although it varies depending on the type of non-aqueous solvent, gelling agent, and electrolyte salt used, when polyacrylonitrile is used as the gelling agent, the molar ratio of the monomer that is a repeating unit of polyacrylonitrile and the non-aqueous solvent. Is preferably 5:95 to 30:70.

  In particular, when the gelling agent is polyacrylonitrile and the non-aqueous solvent is a mixed solvent of ethylene carbonate and propylene carbonate, the composition ratio of the monomer, which is a repeating unit of polyacrylonitrile, to ethylene carbonate and propylene carbonate is as shown in FIG. It is desirable that the region be surrounded by four points A, B, C, and D on the ternary composition diagram shown in FIG.

  When the ratio of the acrylonitrile monomer is outside this region, the gelation does not proceed sufficiently and a good gel electrolyte cannot be obtained. On the contrary, when the ratio of the acrylonitrile monomer is larger than this region, the film formability tends to be impaired. Since the ionic conductivity of the gel electrolyte also changes depending on the amount of polyacrylonitrile added, the gel electrolyte may have a desired ionic conductivity by controlling this ratio. As a result, the gel electrolyte can have an ionic conductivity in a range that cannot be obtained with a non-aqueous electrolyte, and for example, a battery that can withstand high temperature use can be realized.

In the case of using LiPF ₆ as an electrolyte salt, it is desirable that the concentration is 0.4~2M to non-aqueous solvent. If the concentration of the electrolyte salt with respect to the non-aqueous solvent is less than 0.4M, sufficient ionic conductivity cannot be obtained. On the contrary, when the concentration of the electrolyte salt with respect to the non-aqueous solvent exceeds 2M, the dissolution of the electrolyte salt becomes difficult, and the viscosity of the entire gel increases, leading to an extreme decrease in ionic conductivity.

  An electrolyte material using a polymer having a nitrile group in the side chain is also proposed in Japanese Patent Laid-Open Nos. 4-253316, 6-271774, and 6-279647.

  Among them, the electrolyte material described in JP-A-4-253316 is a polymer solid film mainly composed of polyacrylonitrile containing lithium ions. This electrolyte material has been proposed especially assuming the use of a capacitor, and has been designed with a focus on impedance frequency characteristics. Therefore, this publication does not describe any specific conditions for obtaining flame retardancy and high ionic conductivity, but rather mentions that it is a low ionic conductor as one of its features.

On the other hand, the electrolyte materials described in JP-A-6-271774 and JP-A-6-279647 are composed only of a polymer having a nitrile group and an alkali metal salt, and are completely impregnated with a nonaqueous solvent. It is a solid electrolyte. This electrolyte material is assumed to be applied to batteries, and one of the purposes is to improve ionic conductivity. However, the ionic conductivity is also on the order of 10 ⁻⁶ to 10 ⁻⁵ S / cm, and cannot be said to be sufficiently large.

  On the other hand, the gel electrolyte proposed in the present invention is obtained by gelling a non-aqueous electrolyte composed of a non-aqueous solvent and an electrolyte salt with a polymer having a nitrile group, for example. is there. This gel electrolyte has flame retardancy and can have an ionic conductivity of 1 mS / cm or more. That is, the electrolyte material proposed in the above three publications has a configuration different from that of the electrolyte material described in these publications when applied to a battery. It is.

  The gel electrolyte as described above is used, for example, as an electrolyte material for a battery. The applied battery may be a primary battery specification or a secondary battery specification. In particular, in the case of a secondary battery specification battery, the following are preferable as the positive electrode active material and the negative electrode active material.

That is, as the positive electrode active material, a lithium-containing compound, for example, a general formula Li _X MO ₂ (where M represents one or more transition metals, preferably at least one of Mn, Co, and Ni; 05 ≦ x ≦ 1.10) is used.

  As the negative electrode active material, a lithium metal, a lithium alloy, or a carbonaceous material capable of occluding lithium is used. Examples of carbonaceous materials include pyrolytic carbons, cokes (pitch coke, needle coke, petroleum coke, etc.), graphites, glassy carbons, and organic polymer compound fired bodies (furan resins, etc., fired at an appropriate temperature. Carbonized), carbon fiber, activated carbon and the like.

  By the way, when a non-aqueous electrolyte having a specific composition is gelled by a polymer having a nitrile group in a side chain, for example, flame retardancy that exhibits a high ion conductivity of 1 mS / cm or more in a temperature 25 ° C. environment. The gel electrolyte is obtained.

  Such a gel electrolyte has an ionic conductivity of 1 mS / cm or more and does not contain a substance having poor redox resistance, such as a phosphate ester, and therefore can be used as an electrolyte material for a battery. When this gel electrolyte is used as an electrolyte material for a battery, it has flame retardancy, and thus a battery having excellent safety that does not ignite even when thrown into a fire is realized. Further, a battery using a gel electrolyte as an electrolyte material has an advantage that the electrolytic device does not leak to the outside no matter how it is handled, so that peripheral devices and the like are not contaminated.

An acrylonitrile-based polymer is suitable as a polymer having a nitrile group as a gelling agent in the side chain, and LiPF ₆ is most preferred as an electrolyte salt. When the molar ratio of the monomer that is a repeating unit of the acrylonitrile polymer and the nonaqueous solvent is 5:95 to 30:70 and the concentration of LiPF ₆ is 0.4 to 2 M with respect to the nonaqueous solvent, A gel electrolyte having very high conductivity and excellent flame retardancy is obtained.

  Since the gel electrolyte according to the present invention has flame retardancy and has an ionic conductivity of 1 mS / cm or more in an environment at a temperature of 25 ° C., it can be used as an electrolyte material for a battery.

  When such a gel electrolyte is used as an electrolyte material for a battery, it has flame retardancy, and thus a battery with excellent safety that does not ignite even when thrown into a fire can be constructed. Further, a battery using a gel electrolyte as an electrolyte material has an advantage that the electrolytic device does not leak to the outside no matter how it is handled, so that peripheral devices and the like are not contaminated.

  A preferred embodiment of the present invention will be described based on experimental results.

  The gel electrolyte is obtained by gelling a non-aqueous electrolyte. The gel electrolyte of the present invention is particularly flame retardant and has an ionic conductivity of 1 mS / cm in an environment at a temperature of 25 ° C. It is regulated as above. In this example, first, a material composition for obtaining a gel electrolyte satisfying such conditions was examined.

Examination of composition ratio of non-aqueous solvent and gelling agent A gel electrolyte was prepared as follows.

Polyacrylonitrile, ethylene carbonate (EC) and propylene carbonate (PC) are weighed at the mixing ratios shown in Tables 1 and 2, and EC and PC, which are non-aqueous solvent components, are put into a beaker and mixed. I did. However, in the table, the mixing ratio of polyacrylonitrile is shown by the molar ratio of the monomer which is a repeating unit of polyacrylonitrile. Next, LiPF ₆ was added to the mixed solution at a concentration of 1.0 M and heated to 130 ° C. When sufficiently heated, polyacrylonitrile as a gelling agent was added little by little to this solution. After the addition was completed, stirring was performed while heating for an additional 10 minutes. As a result, a gel solution which is a transparent viscous liquid was obtained. And after developing this gel solution on a glass petri dish, the target gel electrolyte was obtained by cooling at room temperature.

  And about the produced gel electrolyte, the ionic conductivity ((sigma) 1, (sigma) 2) was measured under temperature 25 degreeC and temperature-20 degreeC, and flame retardance was evaluated. The measurement methods of ionic conductivity and flame retardancy are as follows.

Ionic conductivity: The prepared gel electrolyte was cut into a cylindrical shape having a diameter of 1 cm, and sandwiched between a pair of platinum electrode disks having a diameter of 1 cm. In this state, the ionic conductivity of the gel electrolyte was measured using an impedance analyzer. The measurement conditions are an applied voltage of 0.5 mV and a sweep frequency of 5 to 13 MHz.

  Flame retardancy: As shown in FIG. 2, 500 mg of the prepared gel electrolyte 13 was supported on a filter paper (10 cm × 10 cm × 0.01 cm) 12. Then, the filter paper 12 is placed on the support base 14 so that one end opposite to the side on which the gel electrolyte is supported protrudes, and the flame of the gas lighter 11 is directly applied to one end of the protruding filter paper 12. The contact was continued for a minute. After 1 minute, when the gas lighter is moved away from the filter paper, no ignition is observed in the part where the gel electrolyte is supported, or the case where the self-extinguishment immediately occurs is recorded as “non-combustible”, and the ignition is visually Recorded as “ignited” in cases where

  The measurement results are shown in Tables 1 and 2 together with the composition ratio of the gel electrolyte.

  First, from Table 1 and Table 2, when examining the content of polyacrylonitrile, in Experimental Examples 14 and 15 in which the content of acrylonitrile monomer was as small as 2 mol% or 4 mol%, gelation occurred at the gel preparation stage. It was difficult to proceed and it was very difficult to produce a gel electrolyte. For this reason, the electrical conductivity could not be measured. From this, it was found that the ratio of the acrylonitrile monomer contained in the gel electrolyte needs to be 5 mol% or more. However, in Experimental Example 16 in which the content of the acrylonitrile monomer was as large as 30 mol%, the viscosity of the solution was high at the gel preparation stage, and gel formation was relatively difficult. Further, when the monomer content of the gel is increased, such deterioration of the film forming property becomes more remarkable. From this, it was judged that the upper limit of the content rate of an acrylonitrile monomer was 30 mol%.

  Next, looking at the PC content, the gel electrolytes of Experimental Example 4 to Experimental Example 6 in which the PC content was 5 mol% were the same as those in Experimental Examples 1 to 3 in which the PC content was 10 mol%. Compared to the gel electrolyte, the ionic conductivity σ2 in a low temperature environment is about 1/10, which is a very low value. From this, it was found that the proportion of PC contained in the gel electrolyte needs to be 10 mol% or more.

  Further, when the EC content is examined, in the gel electrolytes of Experimental Example 10 to Experimental Example 12 in which the EC content is 10 mol%, the Experimental Examples 7 to 12 in which the EC content is 20 mol%. Compared to the gel electrolyte, the ionic conductivity in a 25 ° C. environment is a relatively low value. From this, it was found that the EC content in the gel electrolyte is desirably 20 mol% or more.

  That is, when polyacrylonitrile is used as the gelling agent and a PC-EC mixed solvent is used as the non-aqueous solvent, it is surrounded by four points A, B, C, and D on the ternary composition diagram shown in FIG. It was found that a gel electrolyte suitable as an electrolyte material can be obtained when the composition ratio in the region is used.

  For further confirmation, a gel electrolyte was prepared by selecting an arbitrary composition ratio within or outside the region surrounded by the four points A, B, C, and D. Similarly, ion conductivity and flame retardancy were produced. Sex was measured. The results are shown in Table 3.

  Thus, the gel electrolyte having a composition in the region has high ionic conductivity and excellent flame retardancy. On the other hand, the gel electrolyte having a composition outside the region has difficulty in film formation and has a low ionic conductivity. This also confirms that the gel electrolyte composition is most preferably in the region surrounded by four points A, B, C, and D on the ternary composition diagram.

Examination of electrolyte salt A gel electrolyte was prepared in the same manner as described above except that acrylonitrile monomer: EC: PC was fixed at 20 mol%: 60 mol%: 20 mol%, and a lithium salt of the type shown in Table 4 was used as the electrolyte salt.

  And the flame-retardant evaluation was performed about the produced gel electrolyte. The results are shown in Table 4.

As shown in Table 4, only the gel electrolyte using LiPF ₆ as the electrolyte salt showed flame retardancy, and ignition was recognized in the gel electrolytes using other electrolyte salts. From this, it was found that LiPF ₆ is suitable as the electrolyte salt of the gel electrolyte.

Next, a gel electrolyte was prepared in the same manner as described above except that acrylonitrile monomer: EC: PC was fixed at 20 mol%: 60 mol%: 20 mol% and LiPF ₆ was contained as an electrolyte salt at a concentration shown in Table 5. .

  The produced gel electrolyte was measured for ionic conductivity (σ1) at a temperature of 25 ° C. and evaluated for flame retardancy. The results are shown in Table 5.

As can be seen from Table 5, the ionic conductivity of the gel electrolyte is a relatively large value of 2.0 or more when the concentration of LiPF ₆ with respect to the solvent is in the range of 0.4 to 2.0 M, but LiPF ₆ When the concentration with respect to the solvent is out of this range, it becomes less than 2.0. From this, it was found that the content of LiPF _{6 in} the gel electrolyte is suitably in the range of 0.4 to 2.0 M with respect to the solvent.

Evaluation of Gel Electrolyte as Electrolyte Material Here, a primary battery and a secondary battery were prepared using a gel electrolyte as an electrolyte material, and the characteristics as the electrolyte material were evaluated. The produced battery is a thin type as shown in FIG. 3 in both cases of the primary battery and the secondary battery.

  First, such a thin type primary battery was produced as follows.

In order to produce the positive electrode plate 1, 85% by weight of manganese dioxide (positive electrode active material), 10% by weight of graphite, and 5% by weight of polyvinylidene fluoride were mixed, and further kneaded with dimethylformamide (DMF) as a solvent. A positive electrode mixture was prepared. And after apply | coating this positive electrode mixture on the aluminum foil used as a collector and drying under reduced pressure at the temperature of 120 degreeC, the positive electrode plate was produced by cutting to a dimension of 8 cm < ² >.

The negative electrode plate 2 was produced by cutting a ² mm thick lithium metal plate into a size of 8 cm ² .

  The positive electrode plate 1 and the negative electrode plate 2 produced as described above are accommodated in the positive electrode outer packaging material 3 and the negative electrode outer packaging material 4, respectively. The positive electrode outer packaging material 3 and the negative electrode outer packaging material 4 are connected to the positive electrode plate 1 and the negative electrode plate 2. Were laminated so that they face each other.

  Next, the gel electrolyte 6 was produced as follows.

A gel solution composed of polyacrylonitrile, EC, PC, and LiPF ₆ was quickly spread on the separator 5 and then cooled at room temperature to form a gel electrolyte 6 having a thickness of 120 μm. Further, the gel electrolyte 6 was formed on the other surface of the separator 5 in the same manner. The ratio of each composition of the gel solution, acrylonitrile monomer: 15mol%, EC: 57mol% , PC: 28mol%, LiPF 6: is a 0.8M to the solvent components. The separator 5 is a nonwoven fabric having a film thickness of about 20 microns.

  The separator 5 thus formed with the gel electrolyte 6 is inserted between the positive electrode plate 1 and the negative electrode plate 2 laminated as described above, and the outer peripheral edges of the positive electrode exterior material 3 and the negative electrode exterior material 4. The parts were joined and sealed by heat-sealing via a hot melt material 7 to produce a thin primary battery.

  The discharge characteristics of the primary battery produced as described above were examined.

The discharge is a constant current discharge performed at a current density of 200 μA / cm ² until the open circuit voltage reaches 1.8V. The measured discharge curve is shown in FIG.

  As can be seen from FIG. 4, the average voltage during discharge of the primary battery is about 2.8 V, and the flatness of the voltage curve is also good. From this, it was confirmed that the gel electrolyte can be sufficiently used as an electrolyte material for a primary battery.

  Next, a thin type secondary battery was produced. In addition, the secondary battery was produced with the material and procedure similar to the case of a primary battery except using lithium cobaltate as a positive electrode active material.

  And the charging / discharging characteristic was investigated about the produced secondary battery.

In the charge / discharge test, constant current charging was performed until the open circuit voltage reached 4.2 V at a current density of 25 μA / cm ^{2. When} this open circuit voltage reached 4.2 V, switching to constant potential charging was performed. Charging was continued until the total charging time reached 20 hours, and then the charging / discharging cycle was repeated at a current density of 200 μA / cm ² until the open circuit voltage reached 2.5 V. The charge / discharge curves for the second and fifth charge / discharge cycles are also shown in FIG.

  As can be seen from FIG. 5, the charge / discharge efficiency of 90% or more is obtained in both the second and fifth charge / discharge cases. From this, it was confirmed that the gel electrolyte can be sufficiently used as an electrolyte material for a secondary battery.

It is a ternary composition diagram showing a preferred composition range of the gel electrolyte according to the present invention. It is a schematic diagram for demonstrating the flame retardance test of gel electrolyte. It is sectional drawing which shows an example of the battery using the gel electrolyte which concerns on this invention. It is a characteristic view which shows the discharge characteristic of the primary battery using the gel electrolyte which concerns on this invention. It is a characteristic view which shows the charging / discharging characteristic of the secondary battery using the gel electrolyte which concerns on this invention.

Explanation of symbols

  1 positive plate, 2 negative plate, 3 separator

Claims (16)

A non-aqueous electrolyte solution in which an electrolyte salt containing at least LiPF ₆ is dissolved in a non-aqueous solvent, and polyacrylonitrile or an acrylonitrile-based copolymer,
The content of acrylonitrile monomer in the non-aqueous solvent and polyacrylonitrile or acrylonitrile-based copolymer is 5 mol% or more and 30 mol% or less,
A gel electrolyte having flame retardancy and having an ionic conductivity of 1 mS / cm or more in an environment at a temperature of 25 ° C.   The acrylonitrile-based copolymer is acrylonitrile / butadiene rubber, acrylonitrile / butadiene / styrene resin, acrylonitrile / polyethylene chloride / styrene resin, acrylonitrile / styrene resin, acrylonitrile / ethylene / propylene / diene / styrene resin, acrylonitrile / vinyl chloride resin, The gel electrolyte according to claim 1, comprising at least one selected from acrylonitrile-methacrylate resins.   The gel electrolyte according to claim 1, wherein the polymer has a number average molecular weight of 50,000 to 500,000.   The gel electrolyte according to claim 1, wherein the non-aqueous solvent of the non-aqueous electrolyte contains at least one selected from ethylene carbonate, propylene carbonate, γ-butyl lactone, methyl ethyl carbonate, or dimethyl carbonate.   The composition ratio between the acrylonitrile monomer and the ethylene carbonate and propylene carbonate constituting the non-aqueous solvent is A (acrylonitrile monomer: 30 mol%, ethylene carbonate: 20 mol%, propylene carbonate 50 mol%), B on the ternary composition diagram. (Acrylonitrile monomer: 5 mol%, ethylene carbonate: 20 mol%, propylene carbonate: 75 mol%), C (acrylonitrile monomer: 5 mol%, ethylene carbonate: 85 mol%, propylene carbonate: 10 mol%), D (acrylonitrile monomer: 30 mol%, ethylene 5. The gel electrolyte according to claim 4, wherein the gel electrolyte is in a region surrounded by four points of carbonate: 60 mol% and propylene carbonate 10 mol%). Gel electrolyte according to claim 1, wherein the concentration of the LiPF ₆ is 0.4M~2M for the nonaqueous solvent.   The gel electrolyte according to claim 1, wherein a molar ratio of the polyacrylonitrile or acrylonitrile-based copolymer to the non-aqueous solvent is 5:95 to 30:70. A non-aqueous electrolyte in which an electrolyte salt containing at least LiPF ₆ is dissolved in a non-aqueous solvent, and polyacrylonitrile or an acrylonitrile copolymer, and acrylonitrile in the non-aqueous solvent and the polyacrylonitrile or acrylonitrile copolymer A gel electrolyte having a monomer content of 5 mol% or more and 30 mol% or less, flame retardancy, and an ionic conductivity of 1 mS / cm or more in an environment at a temperature of 25 ° C;
A gel electrolyte battery comprising a positive electrode and a negative electrode.   The acrylonitrile-based copolymer is acrylonitrile / butadiene rubber, acrylonitrile / butadiene / styrene resin, acrylonitrile / polyethylene chloride / styrene resin, acrylonitrile / styrene resin, acrylonitrile / ethylene / propylene / diene / styrene resin, acrylonitrile / vinyl chloride resin, The gel electrolyte battery according to claim 8, comprising at least one selected from acrylonitrile / methacrylate resins.   The gel electrolyte battery according to claim 8, wherein the polymer has a number average molecular weight of 50,000 to 500,000.   The gel electrolyte battery according to claim 8, wherein the non-aqueous solvent of the non-aqueous electrolyte contains at least one selected from ethylene carbonate, propylene carbonate, γ-butyl lactone, methyl ethyl carbonate, or dimethyl carbonate.   The composition ratio between the acrylonitrile monomer and the ethylene carbonate and propylene carbonate constituting the non-aqueous solvent is A (acrylonitrile monomer: 30 mol%, ethylene carbonate: 20 mol%, propylene carbonate 50 mol%), B on the ternary composition diagram. (Acrylonitrile monomer: 5 mol%, ethylene carbonate: 20 mol%, propylene carbonate: 75 mol%), C (acrylonitrile monomer: 5 mol%, ethylene carbonate: 85 mol%, propylene carbonate: 10 mol%), D (acrylonitrile monomer: 30 mol%, ethylene The gel electrolyte battery according to claim 11, wherein the gel electrolyte battery is in a region surrounded by four points of carbonate: 60 mol% and propylene carbonate 10 mol%. The gel electrolyte battery according to claim 8, wherein the concentration of LiPF ₆ with respect to the non-aqueous solvent is 0.4 M to 2 M.   The gel electrolyte battery according to claim 8, wherein a molar ratio of the polyacrylonitrile or acrylonitrile-based copolymer to the non-aqueous solvent is 5:95 to 30:70.   The gel electrolyte battery according to claim 8, wherein the positive electrode is made of a lithium-containing compound, and the negative electrode is made of a carbonaceous material capable of occluding lithium metal, a lithium alloy, or lithium.   The gel electrolyte battery according to claim 8, wherein the lithium-containing compound constituting the positive electrode is a composite compound of lithium and a transition metal.

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