KR100413734B1 - Gel type polymer electrolyte including leveling agent, lithium metal polymer battery with it, and fabrication method thereof - Google Patents

Abstract

The present invention provides a gel polymer electrolyte containing a leveling agent and a lithium metal polymer battery using the same. According to the present invention, compared with the conventional polymer electrolyte, the charge and discharge efficiency of the lithium electrode, the utilization rate of the lithium electrode, ion conductivity, compatibility with the organic solvent electrolyte, mechanical stability, permeability, etc. can be improved. It is possible to improve the high rate discharge characteristics, battery capacity and cycle life, and battery stability of lithium metal polymer batteries.

Description

GEL TYPE POLYMER ELECTROLYTE INCLUDING LEVELING AGENT, LITHIUM METAL POLYMER BATTERY WITH IT, AND FABRICATION METHOD THEREOF}

The present invention relates to a gel polymer electrolyte containing a leveling agent and a lithium metal polymer battery using the same.

Lithium batteries can be roughly classified into lithium primary batteries and lithium secondary batteries. Lithium primary batteries use lithium as a negative electrode, and Li-MnO ₂ , Li- (CF) n, Li-SOCl _2, etc., depending on the type of positive electrode. These are currently commercially available (JO Besenhard, Handbook of Battery Materials, WILEY-VCH, Weinheim (1999)). In the case of a lithium primary battery, there is a disadvantage in that the dislocation unevenness occurs due to the local dissolution reaction of the lithium electrode, thereby decreasing the utilization rate of the electrode.

Meanwhile, in the case of lithium secondary batteries, a battery using a carbon-based material as a negative electrode and LiCoO ₂ and LiMn ₂ O ₄ as a positive electrode has been commercialized, but a lot of researches have been conducted on lithium negative electrodes to increase the energy density of the battery. (D. Linden, Handbook of Batteries, McGRA-HILL INC., New York (1995)).

Lithium electrodes have a very high theoretical capacity of 3,860 mAh / g, but the charge and discharge efficiency is low and dendrite precipitates on the electrode surface during charging. Such dendrites may cause an internal short circuit, which may cause an explosion.

In order to solve these problems, the above-mentioned problems have been studied by adding an additive to the electrolyte to increase the charge / discharge efficiency and to change the form of lithium deposition, to mix metal fine particles such as Ni and Cu, and to change the composition of the lithium alloy. Attempts have been made to solve this problem (齊藤 外, 第 35 回 電池 討論 會 講演 要旨 集 103 (1994), 第 36 回 電池 討論 會 講演 要旨 集 147 (1995), JO Besenhard, Handbook of Battery Materials, WILEY-). VCH, Weinheim (1999)), yet no solution has been proposed.

On the other hand, it is expected that the dendritic precipitation problem of the lithium electrode can be solved, the polymer electrolyte, the research on this has been made for a long time, summarized as follows.

Conventional polymer electrolytes used in lithium batteries are mainly made of polyethylene oxide (PEO), but recently, polymer electrolytes of gel or hybrid type having ionic conductivity of 10 ⁻³ S / cm or more at room temperature have been developed. Among the polymer electrolytes that are highly applicable to lithium polymer batteries, polyacrylonitrile in a gel form described in US Pat. No. 5,219,679 to KM Abraham et al. And US Pat. No. 5,240,790 to DL Chua et al. And polyvinylidene-fluoride (hereinafter referred to as PVdF) based polymer electrolytes described in US Patent Nos. 5,296,319 and 5,460,904 to AS Gozdz et al.

Gel-type PAN-based electrolytes have excellent adhesion, and thus, adhesion between the composite electrode and the metal substrate is good, and thus, there is an advantage in that the contact resistance is small and the active material is less dropped during charging and discharging of the battery. That is, there is a disadvantage in strength. In particular, these weak strength properties can cause significant problems in the manufacture of electrodes and batteries.

The hybrid PVdF-based electrolyte is prepared by injecting an organic solvent into the small pores by making the polymer matrix porous and submicron or less, and having excellent compatibility with the organic solvent electrolyte. There is an advantage that it can be used as a safe electrolyte without leakage and there is an advantage that the polymer matrix can be prepared in the air because the organic solvent electrolyte is injected later, but the process of extracting the plasticizer and impregnation of the organic solvent electrolyte The manufacturing process is difficult because it is required. In addition, the PVdF-based electrolyte has excellent mechanical strength but poor adhesion, and thus has a critical disadvantage of requiring a heat thinning process and an extraction process in manufacturing electrodes and batteries.

As described in Solid State Ionics, 66, 97, 105 (1993) published recently by O. Bohnke and G. Frand et al., Poly (methyl methacrylate) (hereinafter referred to as PMMA) polymer The electrolyte has a ionic conductivity of 10 ^-3 S / cm at room temperature, excellent adhesion, and excellent compatibility with the organic solvent electrolyte, but the mechanical strength is very weak, it is not suitable for lithium polymer batteries. In addition, J. Electrochem., Published by M. Alamgir and KM Abraham. As described in Soc., 140, L96 (1993), polyvinyl chloride (hereinafter referred to as PVC) -based polyelectrolyte reaches a level of 10 ^-3 S / cm at room temperature and exhibits excellent mechanical strength but low temperature. It is bad and has a disadvantage of large contact resistance.

When the lithium metal polymer battery is manufactured using the polymer electrolyte, the problem of dendritic precipitation can be solved to some extent, but in case of high-rate charging and discharging of more than 1C, the dendritic precipitation problem still exists, and thus, the cycle life and stability must be solved. There is a problem to do. In addition, since the charge and discharge efficiency is low, the excess lithium cathode is required, so there is a disadvantage in that it is not much better than the current commercially available batteries in terms of energy density. Due to these problems, the commercialization of lithium metal polymer secondary batteries using lithium cathodes has not been achieved yet. In addition, even in the case of a lithium primary battery, a lithium electrode has a low utilization rate, and thus an excessive amount of the lithium electrode must be used. As a result, the energy density is low and the battery manufacturing cost is increased.

An object of the present invention is to provide a gel polymer electrolyte having excellent charge and discharge efficiency of lithium electrode, utilization rate of lithium electrode, adhesion, ion conductivity, compatibility with organic solvent electrolyte, mechanical stability, permeability and the like.

It is still another object of the present invention to provide a lithium metal polymer battery having a simple battery manufacturing process and advantageous for large battery size, and having excellent energy density, cycle life, low temperature and high temperature characteristics, high rate charge and discharge characteristics, and stability.

Figure 1 is a graph showing the test results for the charge and discharge efficiency of the lithium polymer polymer battery prepared with a gel polymer electrolyte containing the leveling agent of the present invention and the polymer electrolyte of the comparative example.

Figure 2 is a graph showing the electrode capacity and life test results for the lithium metal polymer battery of the present invention and the battery of the comparative example.

3A and 3B are graphs showing the results of the high rate discharge characteristics test for the lithium metal polymer battery (a) and the battery (b) of the comparative example of the present invention, respectively.

The present invention provides a gel-type polymer electrolyte containing a smoothing agent prepared by mixing a polymer, an organic solvent electrolyte, a smoothing agent, a filler, and a plasticizer, and provides a lithium metal polymer battery prepared by inserting and bonding it between a positive electrode and a lithium negative electrode. .

The polymer used in the gel polymer electrolyte may include a PAN polymer, a PMMA polymer, a PVdF polymer, a PVC polymer, a PEO polymer, a PPO polymer, a PEG polymer, or a blend thereof.

The PAN polymer is selected from the group consisting of polyacrylonitrile and poly (acrylonitrile-methyl acrylate), and the PMMA polymer is poly (methyl methacrylate-co-ethyl acrylate) and poly (methyl methacrylate). -Co-methacrylic acid), the PVdF-based polymer is selected from the group consisting of polyvinylidene difluoride, poly (vinylidene difluoride-hexafluoropropylene) copolymer, the PVC-based polymer Vinyl chloride, poly (vinylidene fluoride-co-acrylonitrile), and PEG-based polymers are polyethylene glycol, polyethylene glycol diacrylate (PEGDA), polyethylene glycol dimethacrylate (PEGDMA), tri Ethylene glycol dimethacrylate (TEGDMA).

Gel polymer electrolyte of the present invention comprises an organic solvent electrolyte, a leveling agent, a filler, a plasticizer.

The organic solvent electrolyte is an ethylene carbonate-dimethyl carbonate (EC-DMC) solution in which lithium salt is dissolved, and an ethylene carbonate-diethyl carbonate (EC-DEC) solution in which lithium salt is dissolved. Or ethylene carbonate-ethyl methyl carbonate (EC-EMC) solution in which lithium salt is dissolved, ethylene carbonate-propylene carbonate in which lithium salt is dissolved, and low temperature characteristics in these solutions. Methyl acetate (MA), methyl propionate (MP), ethyl acetate (EA), ethyl propionate (EP), acetonitrile (AN) ), Butylene carbonate (BC), γ-butyrolactone (γ-BL), tetrahydrofuran (THF), dimethoxye It is composed of one or more materials selected from the group consisting of a solution added with carbon (1,2-dimethoxy ethane, DME) and the like, is added in about 1 to 20 times (100 to 2000% by weight) of the polymer by weight ratio.

The smoothing agent plays a role of uniformly plating lithium on the surface of the lithium electrode during charging. In the charging reaction where lithium is plated on the surface of lithium metal, the potential distribution of the surface of the lithium electrode is not constant due to the reaction characteristics. Because of the concentration of current, lithium is plated on the part to form a protruding part. At this time, the smoothing agent is adsorbed in the part with high electric potential, especially in the protruding part, so as to increase the overvoltage and evenly distribute the electric potential. The part suppresses the reaction to be plated so that the plating reaction in other parts occurs well so that the entire lithium plating is uniform. Due to the uniform lithium plating, dendritic precipitation is suppressed and the potential distribution is uniform, thereby increasing the charge and discharge efficiency, utilization rate, cycle life, and safety of the lithium electrode.

Leveling agents used in the present invention include benzene, toluene, dimethylformamide (DMF), butynediol, butenediol, propargyl alcohol, formalin, coumarin, thiourea, carboxylic acid, allylaldehyde, acetylene derivatives, ethylene, saccharin, allyl Sulfonate, triethanolamine, hexamethylenetetramine, epichlorohydrin, vanillin, licorice, glue, gelatin, glucose, dextrin, gum arabic, β-naphthol, polyacrylamide, iodine compound, polyethylene glycol, polyethylene oxide, cresol sulfonic acid , Amine aldehyde type, sodium thiosulfate, carbonate, sodium acetylene acid, rosemary potassium, lot oil, peptone, thiocarbonate, zanus green, mercapto compound, saccharide, bis (sodium sulfonopropyl disulfide), propylene glycol type, Any one or more substances selected from the group consisting of sulfur compounds and the like are used singly or in mixtures, the addition amount of which is It is used as a 0.1 ~ 10,000 ppm of polymer.

In addition, the filler may be added by 0.1 to 20% by weight of the polymer in order to increase the mechanical strength and ionic conductivity of the gel polymer electrolyte. As the type of filler, a porous inorganic filler such as TiO ₂ , Al ₂ O ₃ , SiO ₂ , and a porous organic filler such as polypropylene, polyethylene, and teflon may be used alone or in combination of two or more thereof.

Plasticizers include dimethyl acetamide (DMA), N, N-dimethylformamide (N, N-dimethylformamide, DMF), dimedyl carbonate (DMC), ethylene carbonate (EC), It is composed of one or more components selected from the group consisting of ethyl methyl carbonate (EMC), propylene carbonate (PC), and acetonitrile (AN), and the amount of plasticizer mixed is 0.1 To 10 times (10% to 1000% by weight).

Preparation of gel polymer electrolyte

The organic solvent electrolyte having a weight of 1 to 20-fold, 0.1 to 10,000 ppm leveling agent, 0.1 to 20% by weight filler, 0.1 using a single or a mixture of two or more of the above-described high molecular materials ~ 10 times of the plasticizer is sufficiently mixed and heated at a temperature between room temperature and 150 ° C to perform polymer blending for about 10 minutes to 2 hours. When a matrix of gel polymer electrolyte is sufficiently formed and a viscosity of several thousand to tens of thousands of cps is obtained, casting is performed by die casting or doctor blade method to prepare a gel polymer electrolyte film. The gel polymer electrolyte film thus prepared is used for the production of a lithium metal polymer battery, which will be described later.

According to the present invention, a polymer matrix is prepared by the above method using only an organic solvent in which lithium salt is not dissolved as another method of gel polymer electrolyte, and then an organic solvent electrolyte in which lithium salt is dissolved is injected into the polymer matrix to form gel. It is also possible to prepare a polymer electrolyte.

Manufacture of Lithium Battery

Method for producing a lithium metal polymer battery using the gel polymer electrolyte containing the leveling agent is as follows.

A gel-type polymer electrolyte containing an organic solvent electrolyte or a polymer matrix containing only an organic solvent is inserted between the lithium cathode and the anode to be bonded and integrated. Then, cut into a certain size, laminated and put into a vacuum package, and the organic solvent electrolyte containing the leveling agent is injected to impregnate the inside of the positive electrode and the polymer matrix and the gel-type polymer electrolyte in the unfilled empty space, and then vacuum sealed by lithium A metal polymer battery is produced.

In this case, the positive electrode used in the lithium metal polymer battery is mixed with an appropriate amount of an active material, a conductive material, a binder, and an organic solvent, as in the method generally used in a conventional lithium ion battery, and then cast on both sides of an aluminum sheet grid, dried, and rolled. Is made by. Specifically, the positive electrode is composed of one or more materials selected from the group consisting of LiCoO ₂ , LiNiO ₂ , LiNiCoO ₂ , LiMn ₂ O ₄ , LiMnO ₂ , MnO ₂ , V ₂ O _5, and V ₆ O ₁₃ , and the lithium negative electrode is lithium or It is made of lithium alloy.

The organic solvent electrolyte is an EC (ethylene carbonate) -DMC (dimethyl carbonate) solution in which lithium salt is dissolved, an EC (ethylene carbonate) -DEC (diethyl carbonate) solution in which lithium salt is dissolved, and EC (ethylene carbonate) in which lithium salt is dissolved Use at least one selected from -EMC (ethylmethyl carbonate) solution and lithium salt dissolved EC (ethylene carbonate) -PC (propylene carbonate) solution. At least one of the above-described leveling agents is added to this organic solvent electrolyte at 0.1 to 10,000 ppm.

MA (methyl acetate), MP (methyl propionate), EA (ethyl acetate), EP (ethyl propionate), BC (butylene carbonate), γ-BL (γ-butyrolactone), DME ( One or more selected from 1,2-Dimethoxyethane), DMA (dimethyl acetamide), and THF (tetrahydrofuran) may be added.

The aluminum grid can be plate, punched plate, expanded plate, porous plate, and efficient inflow of solution when injecting organic solvent electrolyte after lamination. Perforated laminations, expanded laminations, porous laminations are advantageous for this purpose.

Hereinafter, the present invention will be described in more detail with reference to Examples, but these Examples are merely illustrative of the present invention, and the present invention is not limited thereto.

Example 1

15 g of EC-DMC solution in which 1 M LiPF ₆ is dissolved in 3 g of polyacrylonitrile (polyscience, molecular weight 150,000; hereinafter referred to as “PAN”), 0.01 g benzene (smoothing agent), 0.15 g TiO ₂ (filler) And 1g of PC solution was added as a plasticizer, and it mixed for about 12 hours. After mixing, the mixture was heated at 130 ° C. for 1 hour to form a polymer electrolyte matrix roll. Then, when the viscosity is about thousands of cps, which is good for casting, it is applied on a mylar film by a die casting method to prepare a gel polymer electrolyte containing a leveling agent.

The polymer electrolyte was placed between the LiCoO ₂ positive electrode and the Li negative electrode cut to a size of about 3 cm × 4 cm, and laminated. Then, the terminals were welded to the electrode and placed in a vacuum package, and 10 ppm in an EC-DMC solution in which 1M LiPF ₆ was dissolved. After injecting the solution to which benzene was added, vacuum sealing was performed to prepare a lithium metal polymer battery.

The charge / discharge test of the battery was carried out by a charge / discharge method of charging with a C / 2 constant current and a constant voltage of 4.1 V and then discharging with a C / 2 constant current, and the charge and discharge efficiency, electrode capacity, and cycle life based on the anode were investigated. .

Example 2

15 g of EC-DMC solution in which 1 M LiPF ₆ is dissolved in 3 g of polyvinylidene difluoride (Atochem kynar 761; hereafter abbreviated as "PVdF") of PVdF, 0.01 g benzene (smoothing agent), 0.15 g TiO ₂ (filler) 1 g of PC solution was added as a plasticizer and mixed for about 12 hours. After mixing, the mixture was heated at 50 ° C. for about 1 hour to form a polymer electrolyte matrix roll. After that, when the viscosity is about thousands of cps, which is good for casting, it is applied on the mylar film by the die casting method to prepare a gel polymer electrolyte containing a leveling agent.

The polymer electrolyte was placed between the LiCoO ₂ positive electrode and the Li negative electrode cut to a size of about 3 cm × 4 cm and laminated, and the terminals were welded to the electrode in vacuum packaging, and 10 ppm benzene was added in an EC-DMC solution in which 1M LiPF ₆ was dissolved. The added solution was injected and then vacuum sealed to prepare a lithium metal polymer battery.

The charge / discharge test of the battery was carried out by a charge / discharge method of charging with a C / 2 constant current and a constant voltage of 4.1 V and then discharging with a C / 2 constant current, and the charge and discharge efficiency, electrode capacity, and cycle life based on the anode were investigated. .

Example 3

15 g of EC-PC solution in which 1 M LiPF ₆ was dissolved in 3 g of PAN, 0.01 g toluene (smoothing agent), 0.15 g TiO ₂ (filler), and 1 g of PC solution as a plasticizer were added and mixed for about 12 hours. After mixing, the mixture was heated at 130 ° C. for 1 hour to form a polymer electrolyte matrix roll. After that, when the viscosity is about thousands of cps, which is good for casting, it is applied on the mylar film by the die casting method to prepare a gel polymer electrolyte containing a leveling agent.

The electrolyte was placed between a LiCoO ₂ anode and a Li cathode cut to a size of about 3 cm × 4 cm, and laminated. After welding, the terminals were welded to a vacuum package, and 10 ppm of toluene was added to an EC-PC solution in which 1M LiPF ₆ was dissolved. After the injection of the added solution was sealed in vacuum to prepare a lithium metal polymer battery.

The charge / discharge test of the battery was carried out by a charge / discharge method of charging with a C / 2 constant current and a constant voltage of 4.1 V and then discharging with a C / 2 constant current, and the charge and discharge efficiency, electrode capacity, and cycle life based on the anode were investigated. .

Example 4

15 g of EC-EMC solution in which 1 M LiPF ₆ was dissolved in 3 g of PAN, 0.01 g polyethylene glycol (smoothing agent), 0.15 g TiO ₂ (filler), and 1 g of PC solution as a plasticizer were added and mixed for about 12 hours. After mixing, the mixture was heated at 130 ° C. for 1 hour to form a polymer electrolyte matrix roll. After that, when the viscosity is about thousands of cps, which is good for casting, it is applied on the mylar film by the die casting method to prepare a gel polymer electrolyte containing a leveling agent.

The electrolyte was placed between a LiCoO ₂ anode and a Li cathode cut to a size of about 3 cm × 4 cm and laminated, and then the terminals were welded to a vacuum package and placed in a vacuum package. 10 ppm polyethylene glycol was dissolved in an EC-EMC solution in which 1 M LiPF ₆ was dissolved. The added solution was injected and then vacuum sealed to prepare a lithium metal polymer battery.

The charge / discharge test of the battery was carried out by a charge / discharge method of charging with a C / 2 constant current and a constant voltage of 4.1 V and then discharging with a C / 2 constant current, and the electrode capacity and cycle life based on the positive electrode were investigated.

Example 5

15 g of EC-DMC solution in which 1 M LiPF ₆ was dissolved, 3 g of PVdF, 0.01 g butyndiol (smoothing agent), 0.15 g PE (filler), and 1 g of PC solution as a plasticizer were added and mixed for about 12 hours. After mixing, the mixture was heated at 50 ° C. for about 1 hour to form a polymer electrolyte matrix roll. After that, when the viscosity is about thousands of cps, which is good for casting, it is applied on the mylar film by the die casting method to prepare a gel polymer electrolyte containing a leveling agent.

The electrolyte was placed between a LiCoO ₂ anode and a Li cathode cut to a size of about 3 cm × 4 cm, and laminated. After welding, the terminals were welded to vacuum electrodes and placed in a vacuum package. 10 ppm butynediol in an EC-DMC solution containing 1M LiPF ₆ was dissolved. The added solution was injected and then vacuum sealed to prepare a lithium metal polymer battery.

The charge / discharge test of the battery was carried out by a charge / discharge method of charging with a C / 2 constant current and a constant voltage of 4.1 V and then discharging with a C / 2 constant current, and the electrode capacity and cycle life based on the positive electrode were investigated.

Example 6

15 g EC-DMC solution dissolved in 0.5 g PAN, 2 g PVdF and 0.5 g polymethylmethacrylate (purchased from polyscience, molecular weight 100,000; abbreviated as "PMMA") 1 M LiPF ₆ , 0.01 g benzene (smoothing agent) ), 0.15 g TiO ₂ (filler) and 1 g of PC solution as a plasticizer were added and mixed for about 12 hours. After mixing, the mixture was heated at 130 ° C. for 1 hour to form a polymer electrolyte matrix roll. After that, when the viscosity is about thousands of cps, which is good for casting, it is applied on the mylar film by the die casting method to prepare a gel polymer electrolyte containing a leveling agent.

The electrolyte was placed between the LiCoO ₂ positive electrode and the Li negative electrode cut to a size of about 3 cm × 4 cm, and laminated. After welding, the terminals were welded to a vacuum package, and 10 ppm benzene was added to the EC-DMC solution in which 1M LiPF ₆ was dissolved. After the injection of the added solution was sealed in vacuum to prepare a lithium metal polymer battery.

The charge / discharge test of the battery was carried out by a charge / discharge method of charging with a C / 2 constant current and a constant voltage of 4.1 V and then discharging with a C / 2 constant current, and the electrode capacity and cycle life based on the positive electrode were investigated.

Example 7

15 g of EC-DMC solution, 0.01 g benzene (smoothing agent), 0.15 g TiO ₂ (filler), and 1 g of PC solution were added to 3 g of PVdF, and mixed for about 12 hours. After mixing, the mixture was heated at 50 ° C. for about 1 hour to form a polymer electrolyte matrix roll. After that, when the viscosity of about thousands of cps is good for casting, it is applied on the mylar film by the die casting method to prepare a gel polymer electrolyte containing a leveling agent.

The electrolyte was placed between the LiCoO ₂ positive electrode and the Li negative electrode cut to a size of about 3 cm × 4 cm, and laminated. After welding, the terminals were welded to a vacuum package, and 10 ppm benzene was added to the EC-DMC solution in which 1M LiPF ₆ was dissolved. After the injection of the added solution was sealed in vacuum to prepare a lithium metal polymer battery.

The charge / discharge test of the battery was carried out by a charge / discharge method of charging with a C / 2 constant current and a constant voltage of 4.1 V and then discharging with a C / 2 constant current, and the electrode capacity and cycle life based on the positive electrode were investigated.

Example 8

15 g of EC-PC solution in which 1 M LiPF ₆ was dissolved, 0.01 g potassium iodide (smoothing agent), 0.15 g TiO ₂ (filler), and 1 g of PC solution as a plasticizer were added to 3 g of PAN and mixed for about 12 hours. After mixing, the mixture was heated at 130 ° C. for 1 hour to form a polymer electrolyte matrix roll. After that, when the viscosity is about thousands of cps, which is good for casting, it is applied on the mylar film by the die casting method to prepare a gel polymer electrolyte containing a leveling agent.

This electrolyte was placed between a LiCoO ₂ anode and a Li cathode cut to a size of about 3 cm × 4 cm, and laminated. The electrodes were welded to a vacuum package, and then placed in a vacuum package. 10 ppm potassium iodide was dissolved in an EC-PC solution containing 1 M LiPF _6. The added solution was injected and then vacuum sealed to prepare a lithium metal polymer battery.

The charge / discharge test of the battery was carried out by a charge / discharge method of charging with a C / 2 constant current and a constant voltage of 4.1 V and then discharging with a C / 2 constant current, and the electrode capacity and cycle life based on the positive electrode were investigated.

Comparative Example 1

After stacking electrodes and separators in the order of lithium cathode, PE separator, anode, PE separator, and lithium cathode, weld terminals to vacuum packaging, inject EC-DMC solution in which 1M LiPF ₆ is dissolved, and then vacuum seal. To produce a lithium metal polymer battery.

The charge / discharge test of the battery was carried out by a charge / discharge method of charging with a C / 2 constant current and a constant voltage of 4.1 V and then discharging with a C / 2 constant current, and the electrode capacity and cycle life based on the positive electrode were investigated.

Comparative Example 2

9 g of an EC-PC solution in which 1 M LiPF ₆ was dissolved was added to 3.0 g of PAN and mixed for about 12 hours without adding a leveling agent. After mixing, the mixture was heated to 130 ° C. for about 1 hour to form a polymer electrolyte matrix, and then cast by die casting to obtain a polymer electrolyte when the viscosity became about 10,000 cps. After stacking electrodes and polymer electrolyte in the order of lithium anode, polymer electrolyte, anode, polymer electrolyte, and lithium cathode, weld terminals to vacuum packaging, inject EC-PC solution in which 1M LiPF ₆ is dissolved, and then vacuum seal. To prepare a lithium secondary battery.

The charge / discharge test of the battery was carried out by a charge / discharge method of charging with a C / 2 constant current and a constant voltage of 4.1 V and then discharging with a C / 2 constant current, and the electrode capacity and cycle life based on the positive electrode were investigated.

Looking at the characteristics of the lithium metal polymer battery according to the present invention through the above Examples and Comparative Examples are as follows.

1 shows the charge and discharge efficiency of the lithium metal polymer battery prepared according to Examples 1 to 3 and Comparative Examples 1 and 2, the charge and discharge efficiency of the battery prepared by the gel polymer electrolyte of the present invention was excellent.

2 shows charge and discharge characteristics of lithium metal polymer batteries prepared according to Examples 1 to 8 and Comparative Examples 1 and 2, and lithium metal polymer batteries prepared according to Examples 1 to 8 and Comparative Examples 1 and 2. FIG. Was charged and discharged with a C / 2 constant current and a constant voltage of 4.1 V, and then discharged with a C / 2 constant current, and the electrode capacity and cycle life based on the anode were investigated. The electrode capacity and cycle characteristics of the lithium metal polymer batteries prepared according to the embodiment of the present invention from the graph of FIG. 2 are superior to the battery capacity and cycle characteristics of the lithium metal polymer batteries prepared according to the comparative example, and thus the electrode capacity and It can be seen that the life of the battery is improved. This is considered to be because the smoothing agent played a role in increasing the charge and discharge efficiency.

3A and 3B show high-rate discharge characteristics of lithium metal polymer batteries, and the high-rate discharge characteristics of lithium metal polymer batteries prepared according to Example 3 and Comparative Example 2 were charged with a C / 2 constant current and a constant voltage of 4.1 V. , C / 5, C / 2, 1C, 2C constant current was investigated by the charge and discharge method to discharge. From the graph of FIG. 3A, the battery according to the present invention showed 95% and 90% capacity at 1C and 2C discharges for 0.2C discharge, respectively, while the battery according to Comparative Example 2 of FIG. 3B was 87% for 0.2C, respectively. And 56% low performance.

Therefore, it can be seen that the high rate discharge characteristics of the lithium secondary battery manufactured according to the embodiment of the present invention are superior to the high rate discharge characteristics of the lithium metal polymer battery prepared according to the comparative example.

According to the present invention, by preparing a gel polymer electrolyte containing a smoothing agent, the charge and discharge efficiency of the lithium electrode, the utilization rate of the lithium electrode, the ion conductivity, the compatibility with the organic solvent electrolyte, mechanical stability, permeability and the like compared to the conventional polymer electrolyte In the case of manufacturing a lithium metal polymer battery, the lithium metal polymer battery having excellent battery performance such as high rate discharge characteristics, battery capacity and cycle life, and battery stability can be provided. It can be applied to various industrial fields such as power supply of communication equipment and electric vehicle, and can have the effect of localization, import substitution and export increase of various equipment.

Claims (13)

A polymer material comprising any one or a blend thereof selected from a PAN polymer, a PMMA polymer, a PVdF polymer, a PVC polymer, a PEO polymer, a PPO polymer, and a PEG polymer; An organic solvent electrolyte added at a weight ratio of 1 to 20 times the polymer material, A smoothing agent added at 0.1 to 10,000 ppm of the polymer material, Filler is added at 0.1 to 20% by weight of the polymer material, It comprises a plasticizer added in a weight ratio of 0.1 to 10 times the polymer material, The smoothing agent is benzene, toluene, dimethylformamide (DMF), butyndiol, butenediol, propargyl alcohol, formalin, coumarin, thiourea, carboxylic acid, allylaldehyde, acetylene derivative, ethylene, saccharin, allyl sulfonate, triethanol Amine, hexamethylenetetramine, epichlorohydrin, vanillin, licorice, glue, gelatin, glucose, dextrin, gum arabic, β-naphthol, polyacrylamide, iodine compound, polyethylene glycol, polyethylene oxide, cresolsulfonic acid, amine aldehyde type Sodium thiosulfate, carbonate, sodium acetylene, sodium saccharide sugar, lot oil, peptone, thiocarbonate, zanus green, mercapto compound, saccharide, bis (sodium sulfonopropyl disulfide), propylene glycol type, sulfur compound selected from Gel-type polymer electrolyte containing a leveling agent, characterized in that any one or more. The method of claim 1, wherein the organic solvent electrolyte is ethylene carbonate-dimethyl carbonate (hereinafter referred to as "EC-DMC") solution, ethylene carbonate diethyl carbonate (ethylene carbonate- diethyl carbonate (hereinafter referred to as "EC-DEC") solution or lithium salt dissolved ethylene carbonate-ethyl methyl carbonate (hereinafter referred to as "EC-EMC") solution, lithium salt dissolved Ethylene carbonate-propylene carbonate and methyl acetate (MA), methyl propionate (MP) and ethyl acetate (EA) to improve the low temperature properties of these solutions ), Ethyl propionate (EP), acetonitrile (AN), butylene carbonate (BC), γ-butyrola and at least one substance selected from the group consisting of a solution added with ctone, γ-BL), tetrahydrofuran (THF), dimethoxy ethane (1,2-dimethoxy ethane, DME), and the like. Gel polymer electrolyte included. 3. The gel polymer electrolyte of claim 2, wherein the organic solvent electrolyte further comprises a lithium salt. The method of claim 1, wherein the filler is any one or more selected from a porous inorganic filler such as TiO ₂ , Al ₂ O ₃ , SiO ₂ and a porous organic filler such as polypropylene, polyethylene, Teflon is included Gel polymer electrolyte. The method of claim 1, wherein the plasticizer is dimethyl acetamide (DMA), N, N-dimethylformamide (N, N-dimethylformamide, DMF), dimedyl carbonate (dimethyl carbonate, DMC), ethylene carbonate ( ethylene carbonate (EC), ethyl methyl carbonate (EMC), propylene carbonate (PC), and acetonitrile (acetonitrile, AN). Gel polymer electrolyte containing a leveling agent. PAN-based polymer, PMMA-based polymer, PVdF-based polymer, PVC-based polymer, PEO-based polymer, PPO-based polymer, PEG-based polymer material consisting of any one or a combination thereof, and 1 to 20 times of the polymer material A weight ratio of organic solvent electrolyte, 0.1 to 10,000 ppm leveling agent of the polymer material, 0.1 to 20% by weight of filler of the polymer material, and 0.1 to 10 times the weight ratio of the plasticizer of the polymer material, The mixture is heated at a temperature between room temperature and 150 ° C. for about 10 minutes to 2 hours to prepare a polymer matrix. When the viscosity of the polymer matrix is obtained in the thousands to tens of thousands of cps by casting to form a gel polymer electrolyte film, The smoothing agent is benzene, toluene, dimethylformamide (DMF), butyndiol, butenediol, propargyl alcohol, formalin, coumarin, thiourea, carboxylic acid, allylaldehyde, acetylene derivative, ethylene, saccharin, allyl sulfonate, triethanol Amine, hexamethylenetetramine, epichlorohydrin, vanillin, licorice, glue, gelatin, glucose, dextrin, gum arabic, β-naphthol, polyacrylamide, iodine compound, polyethylene glycol, polyethylene oxide, cresolsulfonic acid, amine aldehyde type Sodium thiosulfate, carbonate, sodium acetylene, sodium saccharide sugar, lot oil, peptone, thiocarbonate, zanus green, mercapto compound, saccharide, bis (sodium sulfonopropyl disulfide), propylene glycol type, sulfur compound selected from Gel-type polymer electrolyte manufacturing method containing a leveling agent, characterized in that any one or more 7. The method of claim 6, wherein the organic solvent electrolyte further comprises a lithium salt. The method for preparing a gel polymer electrolyte according to claim 6, further comprising injecting an organic solvent electrolyte in which lithium salt is dissolved into the polymer matrix. A laminate comprising a lithium cathode, a gel polymer electrolyte of claim 1, and a cathode; A terminal connected to each electrode, A battery case containing the laminate and Lithium metal polymer battery is injected into the case and comprises an organic solvent electrolyte containing a leveling agent. 10. The method of claim 9, wherein the organic solvent electrolyte is an ethylene carbonate-dimethyl carbonate (EC-DMC) solution in which lithium salt is dissolved, and ethylene carbonate-diethyl in which lithium salt is dissolved. carbonate (EC-DEC) solution, ethylene carbonate-ethyl methyl carbonate (EC-EMC) solution in which lithium salt is dissolved, ethylene carbonate-propylene carbonate in which lithium salt is dissolved Lithium metal polymer battery, characterized in that any one or more selected from. The method of claim 10, wherein the organic solvent electrolyte is methyl acetate (MA), methyl propionate (MP), ethyl acetate (EA), ethyl propionate to improve low temperature characteristics (ethyl propionate; EP), acetonitrile (AN), butylene carbonate (BC), γ-butyrolactone (γ-BL), tetrahydrofuran (THF), dime Lithium metal polymer battery further comprising any one or more selected from methoxy ethane (1,2-dimethoxy ethane, DME). 10. The method of claim 9, wherein the smoothing agent is benzene, toluene, dimethylformamide (DMF), butyndiol, butenediol, propargyl alcohol, formalin, coumarin, thiourea, carboxylic acid, allylaldehyde, acetylene derivative, ethylene, saccharin, Allyl sulfonate, triethanolamine, hexamethylenetetramine, epichlorohydrin, vanillin, licorice, glue, gelatin, glucose, dextrin, gum arabic, β-naphthol, polyacrylamide, iodine compound, polyethylene glycol, polyethylene oxide, cresol Sulphonic acid, amine aldehyde, sodium thiosulfate, carbonate, sodium acetylene acid, loose potassium, lot oil, peptone, thiocarbonate, zanus green, mercapto compound, saccharide, bis (sodium sulfonopropyl disulfide), propylene glycol type Lithium metal polymer battery, characterized in that any one or a mixture thereof selected from sulfur compounds. The method of claim 9, wherein the anode is at least one material selected from the group consisting of LiCoO ₂ , LiNiO ₂ , LiCoNiO ₂ , LiMn ₂ O ₄ , LiMnO ₂ , MnO ₂ , V ₂ O ₅ and V ₆ O ₁₃ , The cathode is a lithium metal polymer battery, characterized in that lithium or lithium alloy.