JP2001006740A - Lithium secondary battery provided with polymer electrolyte, and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer secondary battery of superior charge/discharge cycle characteristics without providing a new manufacturing facility. SOLUTION: After a group of electrodes comprising a positive electrode 10, a separator 3, and a negative electrode 20 is inserted into a case 40 comprising heat-fusing film including aluminum core material, material comprising electrolyte, polyethylene glycol dimethacrylate as polymer material (monomer), benzoyl peroxide as thermal polymerization initiator, and oxygen absorbing agent mainly comprising cobalt and acid clay which are activated, mixed with each other at rates of 48:50:1:1, is injected to be sealed in the case 40. This is heated at 40 deg.C for 24 hours, so the polymer material is polymerized in the case 40 (inside a battery), thereby a lithium secondary battery is fabricated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a positive electrode, a negative electrode,
The present invention relates to a lithium secondary battery including a polymer electrolyte and a method for manufacturing the same, and more particularly, to improvement of a polymer electrolyte material.

[0002]

2. Description of the Related Art In recent years, lithium-cobalt oxide (LiCo-oxide) has been used as a battery used in portable electronic / communication equipment such as a small video camera, a portable telephone, and a notebook personal computer.
O ₂ ), lithium-nickel oxide (LiNiO ₂ ), lithium-manganese oxide (LiMn ₂ O ₄ ) and other lithium-containing transition metal oxides, etc., are used as the positive electrode active material, and occlude lithium metal, lithium alloy or lithium ions. -A lithium secondary battery represented by a lithium ion battery using a carbon material or the like which can be released as a negative electrode active material attracts attention, and a lithium secondary battery using a carbon material as a negative electrode active material has come into practical use.

Meanwhile, in this type of lithium secondary battery, card type batteries and flexible sheet type batteries have been developed, and lithium secondary batteries using a polymer electrolyte in which an electrolyte is made non-fluidized have been developed. It was started. In a lithium secondary battery equipped with this type of polymer electrolyte, since the electrolyte is non-fluidized, it is possible to prevent the battery from drying due to leakage of the electrolyte and volatilization of the solvent, and to increase the internal impedance or There is an advantage that occurrence of an internal short circuit can be prevented. On the other hand, polymer electrolytes generally have lower ionic conductivity than liquid electrolytes. On the other hand, if a polymer electrolyte is formed in a thin film to improve ion conductivity, a problem arises in that the reaction is not performed uniformly because a thin film having a uniform thickness is difficult to form.

In addition, in a lithium secondary battery provided with a polymer electrolyte, battery characteristics such as charge / discharge cycle characteristics and storage characteristics are greatly affected by the type of polymer used, the structure of the polymer, or the environment in which the polymer is produced. It depends. For this reason, it is known to form a sheet-shaped polymer secondary battery by a thermal polymerization reaction of a non-aqueous electrolyte containing a thermal polymerization initiator and a polymerizable compound (polymer material) in an exterior material containing a positive electrode and a negative electrode. 5-30
No. 36 was proposed.

In the sheet-shaped polymer secondary battery proposed in Japanese Patent Application Laid-Open No. Hei 5-3036, a radical polymerizable compound is dissolved in a non-aqueous electrolyte and polymerized by heat in the presence of a polymerization initiator. Formed by For this reason, after all the battery elements are laminated, they are pressed to a desired thickness and subjected to a heat treatment, whereby a sheet-shaped polymer secondary battery having a desired thickness can be manufactured in one step. As a result, the battery element and the polymer electrolyte can be easily compounded in one step, the thickness of the polymer electrolyte can be easily controlled, and the sheet-shaped polymer secondary battery in which the internal impedance is hardly increased can be produced with high productivity. Obtainable.

[0006]

However, in the sheet-shaped polymer secondary battery proposed in Japanese Patent Application Laid-Open No. Hei 5-3036, since the thermal polymerization reaction is carried out in an oxygen atmosphere (in air), The oxygen concentration inside is high. In general, the thermal polymerization reaction is strongly affected by the oxygen concentration, and a polymer material having a high oxygen concentration is liable to cause a side reaction at the time of the thermal polymerization reaction, and a polymer material having a low oxygen concentration is at the time of the thermal polymerization reaction. It has the property that side reactions are less likely to occur. For this reason, in the method proposed in Japanese Patent Application Laid-Open No. Hei 5-3036, since the oxygen concentration is in a high state, there is a problem that the density of the formed polymer becomes uneven due to side reactions. If the density of the formed polymer is non-uniform, the charge-discharge reaction in the battery becomes non-uniform, which causes a problem that the charge-discharge cycle characteristics deteriorate.

[0007] When the oxygen concentration in the battery is high, oxygen remains in the battery even after the thermal polymerization reaction is completed. Oxygen remaining in the battery accelerates the corrosion of the polymer, causing a problem that the charge / discharge cycle characteristics are deteriorated. Therefore, if the battery is manufactured in an atmosphere in which the oxygen concentration is controlled, such a problem does not occur. However, in order to provide an environment in which the oxygen concentration is controlled, it is necessary to newly control the oxygen concentration. Manufacturing equipment is needed,
Since the equipment cost increases, there is a problem that the cost of this type of battery increases. Therefore, the present invention has been made in order to solve the above-described problems, and has as its object to provide a polymer secondary battery having excellent charge / discharge cycle characteristics without providing a new manufacturing facility. is there.

[0008]

In order to achieve the above object, a lithium secondary battery provided with a polymer electrolyte according to the present invention comprises an oxygen absorber in the battery, and the polymer electrolyte comprises a polymer material. Are thermally polymerized in the battery. When an oxygen absorber is provided in the battery, oxygen present in the battery is absorbed by the oxygen absorber,
Oxygen is removed. When the battery is heated in this state, the polymerization reaction of the polymer material is started by the polymerization initiator, and the polymerization reaction proceeds. At this time, since the oxygen in the battery has been removed, this polymerization reaction proceeds completely, and all polymer materials in the battery are completely polymerized to form a polymer electrolyte. As a result, it is possible to improve the charge / discharge cycle characteristics of the lithium secondary battery including the polymer electrolyte. Furthermore, since the oxygen concentration in the battery can be reduced, equipment for manufacturing the battery in an equipment environment in which the oxygen concentration is controlled becomes unnecessary, and this type of lithium secondary battery can be manufactured at low cost.

Here, the type of the oxygen absorbent is not limited at all, but it is mainly composed of cobalt and acid clay which do not require the supply of water or water vapor, and mainly composed of nickel and zeolite. Preferred are oxygen absorbers that have activated at least one of the following compounds, those containing iron and zeolite as main components, those containing manganese and diatomaceous earth as main components, and those containing copper and zeolite as main components. Among these oxygen absorbers, those obtained by activating those having cobalt and acidic clay as main components, which have high ability as oxygen absorbers, are particularly preferable.

As a method for activating metals such as cobalt, nickel, iron, manganese and copper, thermal catalytic reduction with a reducing gas such as carbon monoxide and hydrogen is preferred. Examples of the location where the oxygen absorbent is filled include mixing into the positive electrode active material and the negative electrode active material, mixing into the positive and negative electrode current collectors, mixing into the battery at the time of manufacturing the battery, and the like. Oxygen absorbent can be enclosed without limitation.

As a solvent for the polymer electrolyte, a mixed solvent of a cyclic carbonate such as ethylene carbonate, propylene carbonate and butylene carbonate and a chain carbonate such as dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate is preferable.
Further, a mixed solvent of a cyclic carbonate and an ether-based solvent such as 1,2-diethoxyethoxyethane is also preferable. The solutes include LiPF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , L
iN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , Li
N (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ), LiC (CF ₃ SO 2
₂ ) ₃ , LiC (C ₂ F ₅ SO ₂ ) ₃ , LiClO ₄ or the like, or a mixture thereof is preferable.

The polymer material used for the polymer electrolyte preferably contains an oxygen atom or a nitrogen atom in the molecule. For example, polyethylene glycol dimethacrylate, polyethylene glycol diacrylate, trimethylolpropane trimethacrylate,
Trimethylolpropane triacrylate, 1,6 hexanediol dimethacrylate, 1,6 hexanediol diacrylate, lauryl methacrylate, lauryl acrylate, furfur acrylate, ethoxylated trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, propoxylation Trimethylolpropane trimethacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated bisphenol A dimethacrylate, ethoxylated bisphenol A diacrylate and the like are preferred, but can be used without being restricted to these types, and two or more of these can be used. They can be used in combination.

As the positive electrode active material, LiCoO ₂ , Li
_{NiO 2, LiMn 2 O 4,} LiCo 0. 5 Ni 0.3 Mn 0.2 O
Lithium-containing transition metal oxide or sulfide are preferred, such as _2, but can be used without being particularly limited thereto. As the negative electrode active material, a graphite material such as natural graphite or artificial graphite, coke, an organic material fired body, lithium metal, a lithium alloy, or a lithium metal or a carbon coating material of a lithium alloy are preferable, but these are particularly limited. It can be used without.

Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, t-butyl hyponitrite, azobisisobutyronitrile, azobisdimethylvaleronitrile, and azobiscyclohexanecarbonitrile. Although more than one species can be used in combination, they can be used without any restriction.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The embodiments of the present invention will be described below in more detail. However, the present invention is not limited to the following embodiments at all, and may be changed as appropriate without departing from the gist thereof. It is possible to carry out.

1. Preparation of positive electrode LiCO ₂ as positive electrode active material, artificial graphite as conductive agent, polyvinylidene fluoride (PVdF) as binder
Were mixed at a weight ratio of 80:10:10, and N-methyl-2-pyrrolidone (NMP) was added thereto to form a slurry. This slurry was applied to one side of an aluminum foil as a positive electrode current collector by a doctor blade method,
After vacuum drying at 150 ° C. for 2 hours, the positive electrode (eg, having a width of 45
mm and a length of 48 mm) 10 were produced. Here, on the upper end of the positive electrode 10, the ear 1 with the positive electrode current collector exposed is provided.
1 is protruding. As the cathode active material, instead of LiCO ₂ described _{above, LiNiO 2, LiMn 2 0 4} , L
A lithium-containing transition metal oxide such as iCo _0.5 Ni _0.3 Mn _0.2 O ₂ or a sulfide may be used.

2. Fabrication of Negative Electrode A carbon powder having a crystal lattice spacing of 002 plane of 3.35 ° and a crystallite size of 1000 ° or more in the C-axis direction and polyvinylidene fluoride (PVdF) as a binder were mixed at a weight ratio of 90:10, N-methyl-2-pyrrolidone (NM
The mixture was slurried by adding P). This slurry is applied to one surface of a Cu foil as a negative electrode current collector by a doctor blade method, and dried in a vacuum at 150 ° C. for 2 hours to form a negative electrode (for example, having a width of 48 mm and a length of 51 mm) 2
0 was produced. Here, a lug 21 from which the negative electrode current collector is exposed protrudes from the upper end of the negative electrode 20. As the negative electrode active material, instead of the carbon powder, graphite of various particle shapes, coke, a carbon material such as an organic fired body, or a lithium metal, a lithium alloy, or a carbon coating material thereof is used. Is also good.

3. Preparation of electrolyte solution Isoform of ethylene carbonate and diethyl carbonate
LiPF in mixed solvent ₆Dissolve 1 mol / l
An electrolyte was prepared. The solvent used for the electrolyte is ethyl
Carbonate, propylene carbonate, butylene carbonate
Cyclic carbonates such as carbonates and dimethyl carbonate
, Methyl ethyl carbonate, diethyl carbonate
Mixed solvents with chain carbonates such as
Carbonates and 1,2-diethoxyethane
A mixed solvent with a tellurium-based solvent can be used. Also,
As the solute, the above LiPF₆Instead of LiBF_Four, Li
CF_ThreeSO_Three, LiN (CF_ThreeSO_Two)_Two, LiN (C_TwoF_Five
SO_Two)_Two, LiN (CF_ThreeSO_Two) (C_FourF₉SO_Two), L
iC (CF_ThreeSO_Two)_Three, LiC (C_TwoF_FiveSO_Two)_Three, Li
ClO_FourEtc. can be used.

4. Production of Lithium Secondary Battery (1) Example 1 A positive electrode 10 was placed in an exterior body (for example, having a width of 54 mm and a length of 85 mm) 40 made of a heat-fusible film using aluminum as a core material. Separator 30 and negative electrode 2
0 was inserted into the electrode group. Thereafter, the exterior body 40
In the above, the above-mentioned electrolyte solution, polyethylene glycol dimethacrylate (average molecular weight: 550, manufactured by Aldrich) as a polymer material (monomer), benzoyl peroxide as a thermal polymerization initiator, and those mainly containing cobalt and acid clay are activated. Weight ratio of oxygenated oxygen absorbent to 48: 5
The mixture mixed at a ratio of 0: 1: 1 was injected, and the
Sealed inside. The oxygen absorber described above is, for example,
Cobalt is subjected to a thermal catalytic reduction treatment with a reducing gas such as carbon monoxide, hydrogen, or the like, and the activated cobalt is carried on the acid clay by 35% by weight.

By heating this at 40 ° C. for 24 hours, the polymer material made of polyethylene glycol dimethacrylate undergoes a polymerization reaction with benzoyl peroxide as a thermal polymerization initiator, and the polymer material is formed inside the outer package 40 (inside the battery). Polymerized. At the start of the polymerization reaction, the oxygen in the air present in the exterior body 40 is completely absorbed by the oxygen absorbent after the exterior body 40 is sealed in the exterior body 40, The atmosphere has no oxygen. Therefore, the polymer material composed of polyethylene glycol dimethacrylate is completely polymerized. Thus, the polymer battery A1 of Example 1 was produced.

(2) Example 2 The same procedure as in Example 1 was carried out except that the above-described positive electrode 10, negative electrode 20, and electrolytic solution were used, and the oxygen absorber to be charged was mainly composed of nickel and zeolite. To polymerize the polymer material to obtain the polymer battery A2 of Example 2.
Was prepared. In the oxygen absorber described above, for example, nickel is subjected to a heat catalytic reduction treatment with a reducing gas such as carbon monoxide or hydrogen, and the activated nickel is supported on zeolite by 30% by weight. .

(3) Example 3 The same procedures as those of Example 1 were carried out except that the above-described positive electrode 10, negative electrode 20 and electrolyte were used, and the oxygen absorber to be introduced was mainly composed of iron and zeolite. In the same manner, the polymer material was polymerized to obtain the polymer battery A of Example 3.
3 was produced. The oxygen absorber described above is, for example,
Iron is subjected to a thermal catalytic reduction treatment with a reducing gas such as carbon monoxide or hydrogen, and the activated iron is supported on zeolite by 35% by weight.

(4) Example 4 The procedure of Example 1 was repeated except that the above-described positive electrode 10, negative electrode 20, and electrolytic solution were used, and the oxygen absorber to be introduced was mainly composed of manganese and diatomaceous earth. The polymer material was polymerized in the same manner to prepare a polymer battery A4 of Example 4. In the oxygen absorber described above, for example, manganese is subjected to a thermal catalytic reduction treatment with a reducing gas such as carbon monoxide or hydrogen, and only 35% by weight of the activated manganese is supported on diatomaceous earth. .

(5) Example 5 The procedure of Example 1 was repeated except that the above-described positive electrode 10, negative electrode 20, and electrolyte were used, and that the oxygen absorber to be introduced was mainly composed of copper and zeolite. The polymer material was polymerized in the same manner to obtain the polymer battery A of Example 5.
5 was produced. The oxygen absorber described above is, for example,
Copper is subjected to a thermal catalytic reduction treatment with a reducing gas such as carbon monoxide or hydrogen, and the activated copper is supported on zeolite by 35% by weight.

(6) Example 6 The same procedures as those of Example 1 were carried out except that the above-mentioned positive electrode 10, negative electrode 20 and electrolytic solution were used, and the oxygen absorber to be introduced was mainly composed of molybdenum and zeolite. The polymer material was polymerized in the same manner to produce a polymer battery A6 of Example 6. The oxygen absorber described above is
For example, molybdenum is subjected to a heat catalytic reduction treatment with a reducing gas such as carbon monoxide or hydrogen, and the activated molybdenum is supported on zeolite by 35% by weight.

(7) Comparative Example Using the positive electrode 10 and the negative electrode 20 described above, an electrolyte solution, polyethylene glycol dimethacrylate as a polymer material (monomer) and benzoyl peroxide in a weight ratio of 49: A polymer battery X of a comparative example was produced by polymerizing the polymer material in the same manner as in Example 1 except that the components were mixed at a ratio of 50: 1.

4. Charge / discharge test Using each of the batteries A1 to A6 and X produced as described above, the battery was charged at a constant current at a current value of 8 mA until the battery voltage reached 4.1 V, and then constant until the battery voltage reached 2.7 V. The current was discharged to make the charge and discharge in the first cycle, and the discharge capacity at this time was defined as the initial discharge capacity. The charge / discharge cycle is repeated up to 100 cycles, and the ratio of the discharge capacity at the 100th cycle to the initial discharge capacity is obtained as a capacity retention ratio (%). The results are as shown in Table 1 below. Was. The initial discharge capacity of each of the batteries A1 to A6 and X was 35 to 40 mAh.

[0028]

[Table 1]

As is clear from the above Table 1, the batteries Al to A6 of Examples 1 to 6 sealed by adding an oxygen absorbent were:
It can be seen that the capacity retention ratio is superior to the battery X of the comparative example. This is because, by providing an oxygen absorber in the battery, oxygen in the battery is removed and polymerization of the polymer electrolyte proceeds completely. For this reason, since the density of the polymer electrolyte formed in the battery becomes uniform, the charge / discharge reaction is performed uniformly. As a result, it can be considered that the capacity retention ratio is improved. As a result, the charge / discharge cycle characteristics of a lithium secondary battery including such a polymer electrolyte are improved, and the reliability of a device using the same as a drive power source is improved. And what activated cobalt, nickel, manganese, iron, and copper has an oxygen absorption function (deoxygenation function). Among them, especially activated cobalt (used for battery A1).
Has a large deoxygenation function, and therefore has a high capacity retention rate in charge and discharge cycles.

In the above-described embodiment, C
0.050 g of an oxygen absorber activated by one containing o and acid clay as a main component, 0.052 g of an oxygen absorber activated by one containing Ni and a zeolite as a main component, and Fe and a zeolite as a main component 0.048 g of activated oxygen absorber, 0.050 g of activated oxygen absorber based on Mn and diatomaceous earth, and oxygen absorption activated based on Cu and zeolite 0.051
g, Mo, and an example in which 0.050 g of an oxygen absorbent activated with a zeolite as a main component is described. However, the amount of these oxygen absorbents is sufficient to absorb oxygen existing in the battery. What is necessary is just to put in the quantity of. Therefore, the input amounts should be increased as the battery size increases, and decreased as the battery size decreases.

5. Examination of Polymer Material Then, it was examined whether or not the capacity retention ratio differs depending on the polymer material added in the battery. (1) Example 7 A positive electrode 10, a negative electrode 20, an electrolytic solution and an oxygen absorbent (containing cobalt and acid clay as main components, similar to those of Example 1 described above,
Cobalt A7 of Example 7 was obtained by polymerizing the polymer material in the same manner as in Example 1 except that trimethylolpropane trimethacrylate was used as the polymer material to be charged. Produced. In addition, the input amount of the oxygen absorbent was 0.050 g.

(2) Example 8 A positive electrode 10, a negative electrode 20, an electrolytic solution and an oxygen absorbent (containing cobalt and acid clay as main components, similar to those of Example 1 described above)
The polymer battery of Example 8 was obtained by polymerizing the polymer material in the same manner as in Example 1 except that a polymer material obtained by activating cobalt) was used and 1,6 hexanediol dimethacrylate was used as the polymer material to be charged. A8 was produced. The amount of the oxygen absorbent added was 0.051 g.

(3) Example 9 The same positive electrode 10, negative electrode 20, electrolytic solution and oxygen absorbent (cobalt and acid clay as main components,
Cobalt was activated), and the polymer material was polymerized in the same manner as in Example 1 except that lauryl acrylate was used as the polymer material to be charged.
A polymer battery A9 of Example 9 was produced. In addition, the input amount of the oxygen absorbent was 0.050 g.

Then, using each of the batteries A7 to A9 produced as described above, the battery voltage was 4.1 at a current value of 8 mA.
After the battery was charged at a constant current until the battery voltage reached V, the battery was discharged at a constant current until the battery voltage reached 2.7 V. The charge and discharge in the first cycle were performed. The discharge capacity at this time was defined as the initial discharge capacity. The charge / discharge cycle is repeated up to 100 cycles, and the ratio of the discharge capacity at the 100th cycle to the initial discharge capacity is obtained as a capacity retention ratio (%). The results are shown in Table 2 below. Was. In addition, each battery A7
A9 had an initial discharge capacity of 38 to 40 mAh.

[0035]

[Table 2]

As is apparent from Table 2, the capacity retention ratio can be improved regardless of the type of the polymer material. The polymer material constituting the polymer electrolyte includes polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, 1,6 hexanediol dimethacrylate, and lauryl acrylate, as well as polyethylene glycol diacrylate and trimethylolpropane triacrylate. 1,6 hexanediol diacrylate, lauryl methacrylate, furfur acrylate, ethoxylated trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane trimethacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated Bisphenol A dimethacrylate, ethoxylated bisphenol A diaclair Those containing molecular oxygen and nitrogen atoms in the like are preferable.

In the above-described embodiment, the amount of the metal such as Co, Ni, Fe, Mn, Cu, and Mo, which serves as an oxygen absorbent, is adjusted with respect to these carriers (acid clay, zeolite, and diatomaceous earth). Although an example in which 30% by weight or 35% by weight is added has been described, the amount of addition of these metals is generally considered to have a large effect of oxygen absorption.
It may be appropriately determined within the range of 50% by weight to 50% by weight. Further, in the above-described embodiment, an example in which the oxygen absorbent is enclosed in the outer casing together with the electrolytic solution has been described, but the oxygen absorbent is enclosed in the positive electrode active material or the negative electrode active material, and the positive and negative electrode Various means such as mixing into an electric body and mixing into an empty space in a battery at the time of manufacturing the battery can be adopted.

Further, in the above-described embodiment, an example has been described in which benzoyl peroxide is used as the thermal polymerization initiator. However, lauroyl peroxide and t-butyl hyponitrite are used as thermal polymerization initiators other than benzoyl peroxide. Almost the same results can be expected by using azobisisobutyronitrile, azobisdimethylvaleronitrile, azobiscyclohexanecarbonitrile, or by using two or more of these.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a lithium secondary battery provided with a polymer electrolyte of the present invention.

[Explanation of symbols]

10 positive electrode, 11 ears, 20 negative electrode, 21 ears, 3
0: separator, 40: exterior body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 4/62 H01M 4/62 Z 10/04 10/04 Z F term (Reference) 4J002 BG041 BG051 BG071 DA076 DA086 DA116 DD037 DG037 DJ006 DJ036 EK048 EZ007 FD117 FD158 FD206 4J011 AA05 PA03 PA06 PA10 PA13 PA14 PA49 PB27 5H003 AA04 AA08 BA01 BA07 BB13 5H028 AA01 AA06 BB03 BB05 BB06 BB10 BB15 CC03 EE03 AE05 AM16 BJ04 BJ12 CJ02 CJ08 CJ11 CJ13 CJ14 CJ28 DJ08 DJ10 EJ01 EJ03 EJ11

Claims (8)

[Claims] 1. A lithium secondary battery comprising a positive electrode, a negative electrode, and a polymer electrolyte, wherein an oxygen absorbent is provided in the battery, and the polymer electrolyte is obtained by thermally polymerizing a polymer material in the battery. A lithium secondary battery comprising a polymer electrolyte, which is formed. 2. The lithium secondary battery according to claim 1, wherein the polymer electrolyte is thermally polymerized in the battery by a thermal polymerization initiator composed of a peroxide. . 3. The oxygen absorbent is mainly composed of cobalt and acid clay, nickel and zeolite, iron and zeolite, manganese and diatomaceous earth. The lithium secondary battery provided with a polymer electrolyte according to claim 1 or 2, wherein at least one selected from those containing copper and zeolite as main components is activated. 4. The polymer electrolyte according to claim 1, wherein the oxygen absorber is activated by using a material mainly composed of cobalt and acid clay. Rechargeable lithium battery. 5. A method for manufacturing a lithium secondary battery including a positive electrode, a negative electrode, and a polymer electrolyte, comprising: an oxygen absorbent filling step of filling an oxygen absorbent inside the battery; and a polymer inside the battery. A method for manufacturing a lithium secondary battery provided with a polymer electrolyte, comprising: a polymer material filling step of filling a material; and a thermal polymerization step of thermally polymerizing the polymer material filled in the battery. 6. The lithium having a polymer electrolyte according to claim 5, wherein in the polymer material filling step, a polymerization initiator made of a peroxide is filled into the battery together with the polymer material. A method for manufacturing a secondary battery. 7. The oxygen absorbent is mainly composed of cobalt and acid clay, nickel and zeolite, iron and zeolite, manganese and diatomaceous earth. A lithium secondary battery provided with a polymer electrolyte according to claim 5 or 6, wherein at least one selected from those containing copper and zeolite as main components is activated and used. Production method. 8. The polymer electrolyte according to claim 5, wherein a substance mainly composed of cobalt and acid clay is activated and used as the oxygen absorbent. Of manufacturing a lithium secondary battery provided with the same.