JPH1126019A - Manufacture of polyelectrolyte for nonaqueous electrolyte battery and manufacture of the nonaqueous electrolyte battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a battery having good high-rate electric charging discharging at low temperature and superior safety, increase the capacity of the battery and lower its cost by thermally treating a porous polymer and an electrolytic solution at a specific temperature or above. SOLUTION: A porous polymer and an electrolytic solution are manufactured at a temperature of 40 deg.C or above, and a polyelectrolyte has holes holding the electrolytic solution. Ions can pass through not only the electrolytic solution in the holes but also the electrolyte, and high-rate electric charge/discharge can be made. Passages for ions to be quickly diffused are secured by the electrolytic solution in the holes in a nonaqueous electrolyte battery using this electrolyte, and high-rate electric charging/discharging become satisfactory. Even when the injection quantity into the battery is small, the polymer absorbs the electrolytic solution, and the electrolytic solution is uniformly spared to the entire electrode, and sufficient battery performance is obtained. A polyvinylidene fluoride film is processed by the solvent extraction method for generating a porous polyelectrolyte film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polymer electrolyte for a non-aqueous electrolyte battery and a method for producing a non-aqueous electrolyte battery.

[0002]

2. Description of the Related Art A battery using a non-aqueous electrolytic solution and using an alkali metal for the negative electrode can be a high-voltage battery of 3 V or more. However, secondary batteries have the drawback that short-circuiting is likely to occur due to dendritic deposition of alkali metal during charging, and the life is short, and it is difficult to ensure safety due to high reactivity of alkali metal. It is. Therefore, for example, in a lithium battery, instead of metallic lithium, a carbon-based negative electrode such as graphite or carbon in which dendrites of metallic lithium are unlikely to be used is used, and lithium cobaltate or lithium nickelate is used for a positive electrode, so-called lithium. Ion batteries have been devised and used as high energy density batteries.

In the above nonaqueous electrolyte battery, a microporous membrane such as polyethylene or polypropylene is used as a separator. The method for producing a microporous organic polymer membrane includes:
Mainly, a solvent extraction method and a stretching method are used. In the solvent extraction method, a liquid obtained by dissolving an organic polymer in a liquid and spreading it in a sheet shape is immersed in a liquid tank to remove the liquid in which the organic polymer has been dissolved, and the portion from which the liquid has escaped is removed. It is a method for producing a microporous organic polymer membrane having no pores and orientation,
The microporous membrane separator having circular or elliptical holes has been applied to sealed nickel cadmium batteries. The stretching method is a method for producing a microporous film in which a directional hole is formed in a film by stretching an organic polymer film, and is widely applied to secondary batteries. In addition, there is a method for producing a microporous organic polymer film by adding fine particles such as salt and starch into an organic polymer to form a sheet, and then dissolving and removing the fine particles in a liquid. There is also a method of manufacturing a microporous organic polymer film in which an organic polymer is dissolved in a liquid at a high temperature and cooled to solidify the organic polymer and then remove the liquid. In addition, a separator is provided with a battery safety mechanism by utilizing a shutdown effect in which pores are closed by melting of a microporous organic polymer film due to heat. With this mechanism, even when the battery generates heat and enters a dangerous state, it is possible to insulate between the positive electrode and the negative electrode, and further suppress the reaction between the positive electrode and the negative electrode.

A non-aqueous battery uses a flammable organic electrolyte for the electrolyte, unlike lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, etc., which use an aqueous solution for the electrolyte, thus enabling safe use of the battery. Because of the safety problems, safety valves, protection circuits, PTC elements, etc.
It is necessary to provide various safety elements, and there is a problem that the cost is high.In addition, since the utilization rate of the active material is limited due to the problem of the battery safety, the energy density of the battery is reduced. There is a problem that the value is much smaller than expected from the theoretical capacity. Therefore, it has been attempted to improve the safety of the battery by using a solid polymer electrolyte having less chemical reactivity instead of the organic electrolyte. Also, application of solid polymer electrolytes has been attempted for the purpose of flexibility of battery shape, simplification of manufacturing process, reduction of manufacturing cost, and the like.

As the polymer electrolyte, many studies have been made on complexes of polyethers such as polyethylene oxide and polypropylene oxide with alkali metal salts. But,
Polyether is difficult to obtain high ionic conductivity while maintaining sufficient mechanical strength, and since the conductivity is greatly affected by temperature, sufficient conductivity cannot be obtained at room temperature. Attempts have been made to use a comb-type polymer having an ether in the side chain, a copolymer of a polyether chain and another monomer, a polysiloxane or polyphosphazene having a polyether in the side chain, a crosslinked product of a polyether, and the like.

Further, in a polymer electrolyte in which a salt is dissolved, such as a polyether-based polymer electrolyte, both cations and anions move, and the cation transport number at room temperature is usually 0.5 or less. Therefore, -SO ^3- or -COO ^- by combining a polymer electrolyte having an anionic group such as, but attempts have been made to the transference number of the cation and 1, it is bound to anionic groups strongly cation Therefore, the ionic conductivity was very low, and it was very difficult to use it for batteries.

Further, it has been attempted to produce a gel polymer electrolyte by wetting or swelling the polymer with an electrolytic solution, and to apply it to a non-aqueous battery. Polymers used in the gel polymer electrolyte include polyacrylonitrile, polyvinyl sulfone, polyvinyl chloride, polyvinylidene fluoride, polyvinyl pyrrolidinone, and the like. Attempts have also been made to reduce the crystallinity of the polymer by using a copolymer of vinylidene fluoride and hexafluoropropylene, and to improve the conductivity by facilitating wetting or swelling with an electrolytic solution. Also,
Attempts have also been made to produce a polymer membrane by drying a latex such as nitrile rubber, styrene-butadiene rubber, polybutadiene, polyvinylpyrrolidone, etc., and wetting or swelling it with an electrolyte solution. In the production of a polymer electrolyte using this latex, two types of polymers are mixed, and a polymer phase that does not easily penetrate the electrolyte and maintains strong mechanical strength, and a polymer that easily permeates the electrolyte and exhibits high ionic conductivity A polymer membrane that provides mechanical strength and ionic conductivity by using a mixed system with a phase has been proposed.

Further, in order to enhance the mechanical strength of the polymer electrolyte membrane and to improve the ease of handling, a solid electrolyte in which the polymer electrolyte is filled in the pores of the polyolefin microporous membrane, an ionic conductivity improvement and An organic polymer electrolyte containing an inorganic solid electrolyte powder for the purpose of increasing the cation transport number has also been reported.

However, in lithium batteries and non-aqueous electrolyte batteries such as lithium ions, most of the amount of lithium ions involved in the electrode reaction in the charge / discharge reaction is not the lithium ions dissolved in the electrolyte, but the activity of the electrodes. Since the lithium ions released from the substance move in the electrolyte and reach the counter electrode, the movement distance of the lithium ions is long. Moreover, while the transport numbers of protons and hydroxide ions in the aqueous battery show values close to 1, the transport numbers of lithium ions in the electrolyte of the nonaqueous electrolyte battery at room temperature are usually 0.5 or less. And the movement speed of the ions in the electrolyte is governed by the concentration diffusion of the ions. Therefore, a battery using a non-aqueous electrolyte has a problem in that the charge / discharge performance at a high rate is inferior to that of an aqueous battery. When a polymer electrolyte is used in place of a non-aqueous electrolyte, the diffusion of ions in the electrolyte is much slower than in a non-aqueous electrolyte, so the charge / discharge performance at high rates and low temperatures is inferior. However, there has been a problem that practical performance cannot be obtained as a main power source of a personal computer, a portable communication device, or the like, which is a main use of the nonaqueous electrolyte secondary battery.

As described above, various organic polymer separators and polymer electrolytes have been proposed. However, it is a safe battery that can make the energy density of the battery almost equal to the value expected from the theoretical capacity of the active material without limiting the utilization rate of the active material due to the problem of battery safety. In addition, there was no non-aqueous electrolyte battery excellent in charge / discharge performance at high rate and low temperature.

[0011]

A conventional non-aqueous electrolyte battery using an organic electrolyte solution uses polyethylene or polypropylene, which does not swell or wet with the electrolyte solution and has poor liquid retention ability, as a separator. Therefore, since the separator does not absorb the electrolyte and spread the electrolyte uniformly over the entire electrode, when the amount of the electrolyte injected into the battery is small, the electrolyte is uniformly spread over the entire battery. Not for
Sufficient battery performance was not obtained. Therefore, in order to obtain sufficient battery performance, it is necessary to inject a large amount of the electrolytic solution, and as a result, the electrolyte and the pores of the electrode and the separator and the gap between the electrode and the separator are all occupied by the electrolytic solution. Was. Therefore, when a safety test such as nail penetration is performed, there is no gas that acts as a cushion against local pressure rise near the electrode, and heat is generated at the internal short-circuit point, causing vaporization of the electrolyte near the electrode. The pressure suddenly increases locally, and the reaction that is the starting point of the exothermic chain reaction is likely to occur, and the safety is reduced. Further, the polyethylene or polypropylene separator is hard because it does not swell or wet with the electrolytic solution, and does not change its shape according to the unevenness of the positive and negative electrodes. Therefore, since both the separator and the positive and negative electrodes have irregularities on the surface, there is a gap between them, and a large amount of electrolyte is filled into the gap by injection of the electrolyte. As a result, when the temperature inside the battery rises due to a safety test such as nail penetration, a large amount of electrolyte exists near the electrodes, so the amount of heat generated by the reaction between the electrolyte and the active material increases, and the subsequent explosion The safety is reduced because it triggers an exothermic chain reaction. Therefore, in order to improve the safety of the battery, it is necessary to limit the utilization rate of the active material, thereby limiting the capacity of the battery, and increasing the cost due to the need to provide various safety elements. There was a point.

In a conventional non-aqueous electrolyte battery using a solid electrolyte, the diffusion rate of ions in the solid electrolyte is much lower than that of an organic electrolyte, so that the supply of lithium ions required for an electrode reaction is not sufficient. However, when charging and discharging at a high rate and charging and discharging at a low temperature are performed, sufficient battery performance cannot be obtained.

The present invention has been made in view of the above problems, and is a method for producing a polymer electrolyte for a non-aqueous electrolyte battery, which comprises subjecting a porous polymer and an electrolytic solution to a temperature treatment at 40 ° C. or higher. By using the method for producing a polymer electrolyte according to the present invention, the charge / discharge at a high rate is good even at a low temperature, and it is possible to produce a battery with higher safety than a conventional same energy density battery, and the active material It is possible to increase the capacity of the battery by improving the utilization factor and to reduce the cost of the battery by omitting the safety element.

[0014]

The object of the present invention is achieved by the following invention.

A first invention which is a method for producing a polymer electrolyte for a non-aqueous electrolyte battery, wherein the porous polymer and the electrolyte are subjected to a temperature treatment at 40 ° C. or higher.

A battery provided with a porous polymer and an electrolyte is
A second invention which is a method for producing a non-aqueous electrolyte battery, wherein the temperature treatment is performed at 0 ° C. or higher.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a conventional liquid electrolyte nonaqueous battery, a porous polymer membrane such as polypropylene or polyethylene is used as a separator. Is secured. In this case, the separator is an insulator in ionic conduction, and becomes an obstacle when charging and discharging at a high rate. Further, in a battery using a conventional polymer electrolyte having no pores as an electrolyte, the diffusion of ions in the electrolyte is further slowed down, so that there is a disadvantage that the charge / discharge performance is significantly reduced.

The polymer electrolyte according to the present invention has pores for holding the electrolyte in order to manufacture the porous polymer and the electrolyte at a temperature of 40 ° C. or higher. In the polymer electrolyte according to the present invention, ions can pass not only in the electrolyte solution in the pores but also in the polymer electrolyte, and charge / discharge at a higher rate than conventional liquid electrolyte nonaqueous batteries is possible. . Further, in the non-aqueous electrolyte battery using the polymer electrolyte according to the present invention, a passage through which ions are rapidly diffused by the electrolyte solution in the pores is secured, so that the conventional polymer electrolyte battery having no communication hole is used. The charging / discharging at a higher rate becomes better than that.

In the present invention, when the polymer is swelled or wetted with the electrolyte to form an electrolyte, the polymer absorbs the electrolyte even when the amount of liquid injected into the battery is small.
The electrolyte spreads evenly over the entire electrode. Therefore, by allowing the battery to retain a smaller amount of electrolyte than the amount of electrolyte sufficient to occupy all of the pores, such as the pores of the porous polymer electrolyte and the electrodes, the porous polymer Even in the case where a gas portion is left in the hole of the electrolyte or in the hole of the electrode, sufficient battery performance can be obtained by spreading the electrolyte over the entire electrode. Therefore, when a safety test such as nail penetration is performed, a gas that serves as a cushion against local pressure rise is present near the electrode, and the heat generated at the internal short-circuit location evaporates the electrolyte near the electrode. Even in this case, the local increase in pressure is greatly reduced, and the reaction that is the starting point of the exothermic chain reaction is unlikely to occur, and the safety is improved. Further, since the polymer electrolyte swelled or wetted with the electrolyte is soft, the shape of the polymer electrolyte changes according to the unevenness of the positive and negative electrodes. Therefore, the gap between the polymer electrolyte and the positive / negative electrode is very narrow, and the amount of the electrolyte filled in the gap by the injection of the electrolyte is very small. As a result, if the temperature inside the battery rises due to safety tests such as nail penetration,
Since only a small amount of the electrolytic solution is present in the vicinity of the electrode, the amount of heat generated by the reaction between the electrolytic solution and the active material is reduced, and the subsequent explosive exothermic chain reaction is less likely to occur, thereby improving the safety. Therefore, it is possible to improve the utilization rate of the active material that has been limited to improve the safety of the battery, it is possible to a high-capacity battery,
The cost can be reduced because various safety elements can be omitted. Therefore, it is very important that the polymer electrolyte swells or wets with the electrolytic solution and has excellent liquid retention ability.

In the case where a polymer electrolyte in which a polymer is made into a gel form with an electrolytic solution is manufactured and then wound or laminated with an electrode, the gel containing the electrolytic solution may be in contact with the gas in the working atmosphere over a wide area for a long time. Become. The electrolyte has a strong polarity, and thus has a high water absorption. Even in a low dew point atmosphere such as a dry room, the electrolyte absorbs moisture and adversely affects battery performance. Therefore, after solidifying the polymer in a state where the polymer does not contain the electrolyte, winding or laminating it on the electrode, storing it in the battery case and closing the lid, injecting the electrolyte from the injection port to polymer the polymer. Swelling or wetting to form an electrolyte. However, a polymer that swells or wets sufficiently with an electrolytic solution at room temperature may cause the polymer to swell or wet more than necessary when exposed to a high-temperature atmosphere after the battery is completed. There is a problem of dissolving in water. Conversely, even when the battery is completed and then exposed to a high-temperature atmosphere, a polymer that does not swell or wet unnecessarily or dissolve in the electrolytic solution does not easily swell at room temperature.

In the present invention, it is difficult to swell at room temperature,
The polymer is swollen by heating the porous polymer that does not dissolve in the electrolyte even at a high temperature such as 0 ° C. and the electrolyte at a temperature and for a time such that the polymer swells appropriately. Therefore, in the present invention, a polymer electrolyte that swells moderately with the electrolyte solution and does not dissolve in the electrolyte solution even at a high temperature such as 80 ° C. can be manufactured with a small water content. Therefore, since the polymer electrolyte can be appropriately swollen, the polymer absorbs the electrolyte even when the injection amount of the electrolyte is small, so that the electrolyte is uniformly spread over the entire electrode. In addition, the gap between the polymer electrolyte and the positive and negative electrodes is narrowed, so that the amount of excess electrolyte near the electrodes can be reduced. Further, in the present invention, since the polymer to be swollen or wetted with the electrolytic solution is porous, it can be sufficiently swollen or wet in a very short time as compared with a case where a polymer without pores is used. This is a method for producing a polymer electrolyte excellent in mass productivity.

As a result, by using the present invention, the charge / discharge performance at a high rate and at a low temperature is excellent even with a small amount of electrolyte injected, and as a result, the safety is excellent, and the water content in the electrolyte is also high. A non-aqueous electrolyte battery with a small amount of water can be manufactured. Therefore, in the nonaqueous electrolyte battery according to the present invention, the cost can be reduced by omitting the safety element, and the energy density can be increased by improving the utilization rate of the active material.

[0023]

【Example】

(Embodiment 1) Hereinafter, the present invention will be described using preferred embodiments. The production of the positive electrode will be described. First, 70% by weight of lithium cobalt oxide, 6% by weight of acetylene black, 9% by weight of polyvinylidene fluoride (PVDF), n-
A mixture obtained by mixing 15 wt% of methyl-2-pyrrolidone (NMP) is 20 mm in width, 480 mm in length, and 20 μm in thickness.
And dried at 150 ° C.
The MP was evaporated. After the above operation was performed on both sides of the stainless steel sheet, it was pressed to obtain a positive electrode. The thickness of the positive electrode after pressing was 170 μm, and the weight of the active material, conductive agent, and binder filled per unit area was 23 μm.
g / cm ² .

The negative electrode was manufactured as follows. Graphite 81Wt%, PVDF9Wt%, NMP10Wt%
Was applied onto a nickel sheet having a thickness of 14 μm, and dried at 150 ° C. to evaporate NMP. After performing the above operation on both sides of the nickel sheet,
Pressing was performed to obtain a negative electrode. The thickness of the negative electrode after pressing is 1
It was 90 μm.

Next, a porous PVDF membrane used as a porous polymer electrolyte membrane between the positive electrode and the negative electrode was produced by a solvent extraction method as follows. PVD with a molecular weight of 60,000
12 g of F powder was dissolved in 88 g of NMP to produce a PVDF paste. This PVDF paste was applied on a polyethylene-coated silica paper with a doctor blade method with a blade gap of 100 μm, and was immersed in water to replace NMP with water. A 25 μm PVDF membrane was produced.

The PVDF porous polymer membrane thus prepared, the positive electrode and the negative electrode are stacked and spirally wound, and the height is 4
The battery was inserted into a stainless steel case having a size of 7.0 mm, a width of 22.2 mm and a thickness of 6.4 mm, and was covered with a lid by laser welding to assemble a prismatic battery. Inside this battery, ethylene carbonate (EC) and diethyl carbonate (DE)
C) and 1: 1 by volume, and 1 mol / l of Li
The electrolyte solution to which PF ₆ was added was added by vacuum injection from the injection port, and then the injection port was closed with a ball seal to seal the battery case. The battery manufactured in this way is
At 50 ° C, 50 ° C, 60 ° C, 70 ° C and 80 ° C.
After heating for a time, the PVDF porous polymer was swollen with an electrolytic solution to obtain a porous polymer electrolyte. In this way, the batteries A, B, C, D and E of Example 1 using the present invention having a nominal capacity of about 400 mAh (the heating temperature was 40 ° C., 5
0 ° C, 60 ° C, 70 ° C and 80 ° C). In addition,
In each of the batteries A, B, C, D, and E according to the present invention, several types of batteries were manufactured by changing the amount of electrolyte injected between 1.8 and 2.6 g. In the battery according to the present invention, by using PVDF having different molecular weights, the wettability or swelling of the electrolytic solution can be controlled.

As Comparative Example 1, a battery having a nominal capacity of about 400 mAh is conventionally known in the same manner as in Example 1 except that the battery was left at 25 ° C. for 48 hours instead of being heated at 40 ° C. or higher. Battery (F) was produced.

As Comparative Example 2, except that a stretched polypropylene membrane having a thickness of 25 μm and a porosity of 40% was used instead of the PVDF porous polymer membrane, and the battery was not heated at 40 ° C. or higher. Manufactured a conventionally known battery G having the same configuration as that of Example 1 described above and a nominal capacity of about 400 mAh.

In the conventionally known batteries F and G, similarly to the batteries A, B, C, D and E according to the present invention, the amount of electrolyte injected is between 1.8 and 2.6 g. Several types of batteries were manufactured with variations.

The batteries A, B, C, D and E according to the invention
And 25 ° C. using batteries F and G which are conventionally known.
, The battery was charged to 4.1 V with a current of 1 CA, subsequently charged for 2 hours at a constant voltage of 4.1 V, and then discharged to 2.75 V with a current of 2 CA.

FIG. 1 is a diagram showing the relationship between the discharge capacity of these batteries and the weight of the electrolyte injected into the batteries. From the figure, it is understood that the batteries A, B, C, D, and E according to the present invention exhibit excellent high-rate discharge performance with a smaller amount of electrolyte injected than the conventionally known batteries F and G. Is done.
It is also understood that the batteries A, B, C, D, and E according to the present invention exhibit excellent high-rate discharge performance with a smaller amount of electrolyte injected as the heating temperature is higher.

It should be noted that the conventionally known battery G
At 50 ° C, 50 ° C, 60 ° C, 70 ° C and 80 ° C.
After heating for an hour, the same test was performed, but the result was the same as when no heating was performed.

Further, batteries A, B, C, D according to the present invention
And E, and conventionally known batteries F and G, the following safety comparison test was performed. Each of the above batteries was charged to 4.5 V at a current of 1 CA at 25 ° C., and then charged for 2 hours at a constant voltage of 4.5 V. After that, a 3 mm-diameter nail was pierced by penetrating the battery. Table 1 shows the results. In the above-described safety test, the amount of electrolyte injected into each battery was the minimum amount at which the discharge capacity at the time of 2CA discharge at 25 ° C. became about the nominal capacity. Table 1 shows the electrolyte weight of each battery.

[0034]

[Table 1] From these results, it can be said that the batteries A, B, C, D, and E according to the present invention are batteries having higher safety than the conventionally known batteries F and G, and the present invention was used. In the battery, it can be said that a battery heated at a higher temperature has a higher safety.

In the above embodiment, PVDF was used as the polymer used for the polymer electrolyte. However, similar battery fabrication, charge / discharge tests and safety tests were carried out using polyacrylonitrile and polyvinyl chloride instead of PVDF. As a result, the same results were obtained as when PVDF was used.

In the above embodiment, the heat treatment was performed after the battery was sealed by the ball seal. However, even when the open system battery was heat-treated before the battery was sealed by the ball seal, the present invention can be applied. Similar results were obtained. Even if the heat treatment is performed in an open system, the contact area between the electrolyte and the atmosphere outside the battery is small compared to the electrode area. Was able to sufficiently reduce the amount of water absorbed.

In the above embodiment, polyvinylidene fluoride is used as the polymer of the polymer electrolyte. However, the polymer of the polymer electrolyte in the present invention is not limited to this. Such as polyether, polyacrylonitrile, polyvinylidene fluoride, polyvinylidene chloride, polymethyl methacrylate, polymethyl acrylate, polyvinyl alcohol, polymethacrylonitrile, polyvinyl acetate, polyvinyl pyrrolidone, polyethylene imine, polybutadiene, polystyrene, polyisoprene, or These derivatives may be used alone or as a mixture. In addition, each of the above polymers may be a copolymer containing the polymer as a main component.

In the battery of the above embodiment, PVDF made porous by a solvent extraction method was used as the porous polymer electrolyte. However, the method of making the polymer porous in the present invention is not limited to this. Alternatively, any of a stretching method, a method using a foaming agent, a method of bonding powder, or a method of depositing a solid in a polymer may be used.

Further, in the battery of the above embodiment, the porous polymer is solidified and then spirally wound on the positive electrode and the negative electrode. However, the present invention is not limited to this. The conductive polymer may be solidified on the positive electrode or the negative electrode. Further, the porous polymer electrolyte may be filled in the holes of the active material layer of the positive electrode or the negative electrode. The element may be a laminated body other than the spirally wound body.

In the present invention, the porous polymer to be heated together with the electrolytic solution may already be a polymer electrolyte before heating. Even in this case, swelling or wetting is promoted by heating, and a more excellent polymer electrolyte can be obtained.

Further, in the battery of the above embodiment, a mixed solution of EC and DEC is used as the non-aqueous electrolyte, but the present invention is not limited to this, and ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate Carbonate, γ-butyrolactone,
Sulfolane, dimethyl sulfoxide, acetonitrile,
Dimethylformamide, dimethylacetamide, 1,2
A polar solvent such as -dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dioxolan, methyl acetate, or a mixture thereof may be used.

Further, in the above embodiment, LiPF ₆ is used as a salt contained in the non-aqueous electrolyte.
In addition, LiBF ₄ , LiAsF ₆ , LiClO ₄ ,
LiSCN, LiI, LiCF ₃ SO ₃ , LiCl, L
A lithium salt such as iBr or LiCF ₃ CO ₂ or a mixture thereof may be used.

Further, in the above embodiment, the compound capable of occluding and releasing the alkali metal as the positive electrode material is LiC
Although oO ₂ was used, it is not limited to this.
In addition, as the inorganic compound, the composition formula LixMO
₂ or LiyM ₂ O ₄ (where M is a transition metal, 0 ≦
Complex oxides, oxides having tunnel-like vacancies, and metal chalcogenides having a layered structure represented by x ≦ 1, 0 ≦ y ≦ 2) can be used. As a specific example, Li
CoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , Li ₂ Mn
₂ O ₄ , MnO ₂ , FeO ₂ , V ₂ O ₅ , V ₆ O ₁₃ , T
iO ₂ , TiS _{2 and the} like. Examples of the organic compound include a conductive organic polymer such as polyaniline. Further, the above-mentioned various active materials may be mixed and used regardless of an inorganic compound or an organic compound.

Further, in the above embodiment, graphite is used as a compound as a negative electrode material. In addition, alloys of lithium with Al, Si, Pb, Sn, Zn, Cd, etc., LiFe ₂ O _3, etc. Transition metal composite oxide,
Transition metal oxides such as MoO ₂ and tin oxide, carbonaceous materials such as graphite and carbon, lithium nitride such as Li ₅ (Li ₃ N), or metallic lithium foil, or a mixture thereof may be used.

[0045]

According to the present invention, it is difficult to swell at room temperature,
The polymer is swollen by heating the porous polymer that does not dissolve in the electrolyte even at a high temperature such as 80 ° C. and the electrolyte at a temperature and for a time such that the polymer swells appropriately. Therefore, in the present invention, it is possible to manufacture a polymer electrolyte that swells moderately with the electrolyte and does not dissolve in the electrolyte even at a high temperature such as 80 ° C. Therefore, since the polymer electrolyte can be appropriately swollen, the polymer absorbs the electrolyte even when the injection amount of the electrolyte is small, so that the electrolyte is uniformly spread over the entire electrode. In addition, the gap between the polymer electrolyte and the positive and negative electrodes is narrowed, so that the amount of excess electrolyte near the electrodes can be reduced. Further, in the present invention, since the polymer to be swollen or wetted with the electrolytic solution is porous, it can be sufficiently swollen or wet in a very short time as compared with a case where a polymer without pores is used. This is a method for producing a polymer electrolyte excellent in mass productivity.
Furthermore, by heating the porous polymer and the electrolyte solution in the present invention in the battery case, a polymer electrolyte having a small water content can be manufactured.

As a result, by using the present invention, the charge / discharge performance at a high rate and at a low temperature is excellent even with a small amount of injected electrolyte, and as a result, the safety is excellent, and the water content in the electrolyte is also high. A non-aqueous electrolyte battery with a small amount of water can be manufactured. Therefore, in the nonaqueous electrolyte battery according to the present invention, the cost can be reduced by omitting the safety element, and the energy density can be increased by improving the utilization rate of the active material.

[Brief description of the drawings]

FIG. 1 is a diagram comparing the relationship between electrolyte weight and discharge capacity of a battery according to the present invention and a conventional battery.

Claims (2)

[Claims] 1. A method for producing a polymer electrolyte for a non-aqueous electrolyte battery, comprising subjecting a porous polymer and an electrolytic solution to a temperature treatment at 40 ° C. or higher. 2. A method for producing a non-aqueous electrolyte battery, comprising subjecting a battery provided with a porous polymer and an electrolytic solution to a temperature treatment at 40 ° C. or higher.