KR100329569B1 - Lithium secondary battery - Google Patents

Abstract

The present invention forms an electrode active material layer on each current collector using an electrode active material composition containing an electrode active material, a conductive agent, a binder, acetone and ethanol to remove the ethanol, thereby forming a cathode, an anode, and a polymer resin. At least one plasticizer selected from 5 to 60 parts by weight of dialkyl carbonate, alkylene carbonate and dialkoxy ethane and 10 to 50 parts by weight of inorganic filler based on 100 parts by weight of the polymer resin, and having no pores. The present invention provides a lithium secondary battery, comprising: a separator, wherein the separator is laminated between the cathode and the anode. In the lithium secondary battery according to the present invention, the plasticity is imparted to the electrode and the separator, and the lamination process is smooth. As a result, a battery structure having reduced interface resistance between the electrode and each layer of the separator can be obtained. Since the electrolyte can be injected directly without going through the drying process, the manufacturing time is reduced.

Description

Lithium secondary battery

The present invention relates to a lithium secondary battery, and more particularly, to remove and remove a plasticizer using an organic solvent, and to facilitate lamination between an electrode and a separator, a lithium secondary battery having reduced interfacial resistance between layers. It is about.

Lithium secondary batteries can be divided into lithium ion batteries using liquid electrolytes and lithium ion polymer batteries using solid electrolytes, depending on the type of electrolyte. Among them, the lithium ion polymer battery uses a solid electrolyte, so there is little risk of leakage of the electrolyte, and the processability can be made into a battery pack. It is light in weight, low in volume, and has a very small self-discharge rate. Due to these characteristics, lithium ion polymer batteries are not only safer than lithium ion batteries, but also easy to manufacture with square and large size batteries.

1 is a view showing an example of a conventional lithium ion polymer battery.

Referring to this, the lithium ion polymer battery includes a battery assembly 11 formed by stacking a cathode, an anode, and a separator, and a case 12 surrounding and sealing the battery assembly 11. In addition, the electrode tab 13 serving as an electrical passage between the battery assembly 11 and the outside is connected to a connection tab 13 'provided at the cathode and the anode, and the electrode tab 13 extends out of the case 12 by a predetermined length. Exposed.

In the battery assembly, the cathode and the anode are formed by forming an active material layer of each electrode active material composition on each electrode current collector. In order to form a battery assembly, the separators are laminated on both sides of the anode obtained according to the above method, and the cathodes obtained according to the above procedure are disposed on the separators, and the laminations are formed to form a bicell structure. Is common. At this time, the cathode, the anode, and the separator are impregnated with an electrolyte solution in the space from which the plasticizer is removed and extracted.

The process of extracting a plasticizer from the above-mentioned electrode and separator is usually performed by impregnation with an organic solvent such as ether and methanol.

On the other hand, U.S. Patent No. 5,418,091 discloses a separator that extracts a part of the plasticizer using a low boiling point extraction solvent capable of selectively extracting only the plasticizer without dissolving the polymer material for forming the separator.

However, when the plasticizer extraction process using the organic solvent is carried out in this way, the solvent used for extraction has a volatility, and there is a difficulty in handling, and when the manufacturing process is complicated and mass-produced, the chemical used to recycle the solvent used in the extraction solvent is used. There is a problem that plant equipment is required. In addition, in a battery assembly formed by laminating an electrode and a separator, there is a problem in that the interfacial resistance between the layers is poor.

The technical problem to be achieved by the present invention is to solve the above problems, to omit the extraction process of the organic solvent for the plasticizer removal, to provide a lithium secondary battery with reduced interfacial resistance by smooth lamination between the electrode and the separator. will be.

1 is a view showing the structure of a conventional lithium ion polymer battery.

<Description of Major Symbols in Drawing>

11 ... battery assembly 12 ... case

13 ... electrode tab 13 '... connection tab

In order to achieve the above technical problem, in the present invention, by forming an electrode active material layer on each current collector using an electrode active material composition containing an electrode active material, a conductive agent, a binder, acetone and ethanol, the ethanol is removed to form pores. Cathode and anode,

A polymer resin, at least one plasticizer selected from 5 to 60 parts by weight of dialkyl carbonate, alkylene carbonate, and dialkoxy ethane based on 100 parts by weight of the polymer resin, and 10 to 50 parts by weight of inorganic filler, wherein the pores are formed. I have a separator that is not

Provided is a lithium secondary battery, wherein the separator is laminated between the cathode and the anode.

The electrode active material layer is formed by directly coating and drying the electrode active material composition on a current collector or by casting and drying the electrode active material composition on a separate support, and then peeling from the support to form an active material layer film. It is formed by lamination.

The technical problem also includes an electrode active material, a conductive agent, a binder and at least one plasticizer selected from 5 to 60 parts by weight of dialkyl carbonate, alkylene carbonate and dialkoxy ethane based on 100 parts by weight of the electrode active material. Unformed cathode and anode,

A polymer resin, one plasticizer selected from 5 to 60 parts by weight of dialkyl carbonate, alkylene carbonate, and dialkoxy ethane based on 100 parts by weight of the polymer resin, and 10 to 50 parts by weight of inorganic filler, wherein the pores are formed. I have a separator that is not

The lithium secondary battery is characterized by laminating the separator between the cathode and the anode.

The present invention provides plasticity to the electrode plate and the separator film by using a plasticizer such as alkylene carbonate, dialkyl carbonate, dialkoxy ethane, etc., which are organic solvents constituting the electrolyte solution in the production of the electrode plate and / or separator. Its feature is to facilitate lamination between plates and separators. At this time, since the plasticizer is not removed, no pores are formed in the electrode and / or separator.

In the lithium secondary battery according to an exemplary embodiment of the present invention, an organic solvent component of the electrolyte as described above is used as a plasticizer in the manufacture of the separator, and an electrode using a phase invenrsion phenomenon using ethanol in the manufacture of the electrode plate. Form pores inside the plate. Therefore, since the plasticizer in the separator is not removed, there are no pores and pores are formed in the electrode plate.

In addition, the lithium secondary battery according to another preferred embodiment of the present invention, both the plasticizer, such as alkylene carbonate, dialkyl carbonate, dialkoxy ethane, etc. in the manufacturing of the separator and electrode plate. In this case, no pores are formed in both the separator and the electrode plate.

Hereinafter, a method of manufacturing a lithium secondary battery according to an exemplary embodiment of the present invention will be described.

First, a porous anode and a cathode are prepared by forming an electrode active material layer on an electrode current collector using an electrode active material composition including an electrode active material, a binder, a conductive agent, acetone, and ethanol, respectively. In this case, the electrode active material layer may be formed by directly coating the active material composition on a current collector and drying at 20 to 40 ° C. Alternatively, the active material composition is cast and dried on a separate support, and then prepared by laminating the active material layer film peeled off from the support onto a current collector. Herein, the support may be used as long as it can play a role of supporting the active material layer film, and specific examples thereof include polyethylene terephthalate (PET) film and mylar film.

In the electrode active material composition, ethanol is almost insoluble in the electrode active material, the binder, and the conductive agent, but is mixed with acetone, and is removed during the subsequent drying process to form pores in the electrode plate.

In the electrode active material of the present invention, a lithium composite oxide such as LiCoO ₂ is used for the cathode, and carbon, graphite, etc. are used for the anode, and carbon black is used as the conductive agent. Herein, the content of the conductive agent is preferably 0.01 to 0.2 parts by weight based on 1 part by weight of the electrode active material (eg, LiCoO ₂ ). In addition, the shape of the current collector is not particularly limited, and in the case of the cathode, all of the extended metal, punched metal, and foil shapes made of aluminum may be used. The anode is the same as the cathode except that the material is copper.

As the binder, vinylidene fluoride-hexafluoropropylene copolymer (VdF / HFP copolymer), polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate or a mixture thereof is used. It is preferably 5 to 30 parts by weight based on 100 parts by weight of the active material.

In the electrode active material composition, the mixing volume ratio of ethanol and acetone is preferably 1: 1 to 1: 5, and most preferably 1: 3. If the mixed volume ratio of acetone to ethanol exceeds the above range, the porosity characteristics in the finally obtained electrode plate are poor, and if the mixed volume ratio of acetone is less than the above range, it is difficult to obtain an electrode active material composition having a uniform composition. It is not preferable to uniformly coat this composition on the current collector as it becomes difficult.

The drying temperature after directly coating the electrode active material composition, casting the electrode active material composition on a support, or laminating the active material layer film on a current collector is preferably maintained at 20 to 40 ° C., for the reason If the drying temperature is less than 20 ℃ is difficult to remove the ethanol to form pores in the electrode plate, it is not preferable, if the drying temperature exceeds 40 ℃ ethanol that makes pores in the separator evaporates quickly, Not evenly

Subsequently, on the anode using a separator composition comprising a polymer resin, a filler, and at least one plasticizer selected from 5 to 60 parts by weight of dialkyl carbonate, alkylene carbonate and dialkoxy ethane based on 100 parts by weight of the polymer resin. A separator without pores is formed. At this time, the separator may be formed by directly coating and drying the composition for forming a separator on the anode. Alternatively, the composition for forming a separator may be cast and dried on a separate support, and then formed by laminating a separator film separated from the support on an anode. Here, after the separator composition is directly coated on the anode, the drying temperature after casting and drying the composition for forming the separator on a separate support or after laminating the separator film on the anode is 25 to 90 degrees. At this temperature, the plasticizer hardly evaporates. Herein, the support may be used as long as it has a function of supporting the separator film, and polyethylene terephthalate (PET) film, mylar film, and the like are used.

When the content of the plasticizer exceeds 60 parts by weight based on 100 parts by weight of the polymer resin, the physical property of the separator film is lowered. When the content of the plasticizer is less than 5 parts by weight, the effect of adding the plasticizer is not preferable.

The polymer resin is not particularly limited, but any material used for the binder of the electrode plate may be used. Vinylidene fluoride / hexafluoropropylene copolymer, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate and mixtures thereof can be used here. Among them, vinylidene fluoride-hexafluoropropylene copolymer or the like having a hexafluoropropylene content of 8 to 25% by weight is particularly preferable. And the filler is a material that serves to improve the mechanical strength of the separator, silica, kaolin, alumina and the like are used.

And the content of the filler based on 100 parts by weight of the polymer resin is preferably 10 to 50 parts by weight. Herein, when the content of the filler to the polymer resin is less than the above range, the ion conductivity and the mechanical properties are not good, and when the content of the filler exceeds the above range, the film is not formed well, which is not preferable.

Thereafter, the cathode is laminated on the separator where the pores are not formed to form a battery structure.

Subsequently, the lithium secondary battery is completed by making the battery structure wet with an electrolyte solution. Here, the electrolyte is composed of a lithium salt and an organic solvent, all of which are commonly used in lithium secondary batteries can be used.

In the lithium secondary battery obtained by the above-described method, a phase inversion phenomenon using ethanol is used in forming pores in the electrode plate without using a plasticizer such as dibutyl phthalate. Herein, ethanol is present in the electrode active material composition and then evaporated and removed in the process of drying the coated composition, leaving pores in the place where ethanol originally exists. Conventional plasticizers must be extracted and removed with an organic solvent such as ether or methanol to form pores in the electrode plate or separator. However, according to this method, the plasticizer does not need to be used and extraction and removal using such an organic solvent is required. There is no need to go through the process. Therefore, various problems caused by using the organic solvent can be prevented. In addition, since the ethanol content of the electrode active material composition is smaller than that of the conventional plasticizer in the composition, it is possible to increase the relative content ratio of the electrode active material, such as lithium composite oxide and graphite, thereby increasing the discharge capacity. There is an advantage to increase. Since the separator does not have a process of removing the plasticizer separately from the electrodes, no pores are formed. In the lithium secondary battery having such a configuration, the plasticizer is contained in the separator, and plasticity is provided between the electrode and the separator film member, resulting in a very smooth lamination between the electrode and the separator. The interfacial resistance of the liver is reduced.

On the other hand, a method of manufacturing a lithium secondary battery according to another preferred embodiment of the present invention is as follows.

Coating an electrode active material composition comprising an electrode active material, a binder, a conducting agent and a plasticizer directly on a current collector and drying at 20 to 40 ° C., or coating and drying the electrode active material composition on a separate support and on the support The anode and the cathode, in which no pores were formed, were prepared by laminating the active material layer film peeled off from the current collector. Here, as the plasticizer, at least one selected from dialkyl carbonate, alkylene carbonate, and dialkoxy ethane is used, and specific examples thereof include ethylene carbonate, propylene carbonate, dimethyl carbonate, dipropyl carbonate, diethyl carbonate, and diethoxyethane. , Dimethoxyethane and mixtures thereof. And the content of the plasticizer is 5 to 60 parts by weight based on 100 parts by weight of the electrode active material.

Subsequently, on the anode using a separator composition comprising a polymer resin, a filler, and at least one plasticizer selected from 5 to 60 parts by weight of dialkyl carbonate, alkylene carbonate and dialkoxy ethane based on 100 parts by weight of the polymer resin. A separator without pores is formed. At this time, the separator may be formed by directly coating and drying the composition for forming a separator on the anode. Alternatively, the composition for forming a separator may be cast and dried on a separate support, and then formed by laminating a separator film separated from the support on an anode. Here, after the separator composition is directly coated on the anode, the drying temperature after casting and drying the composition for forming the separator on a separate support or after laminating the separator film on the anode is 25 to 90 degrees. At this temperature, the plasticizer hardly evaporates.

On the separator, the cathode is laminated to form a battery structure. Subsequently, the lithium secondary battery according to the present invention is completed by impregnating the battery structure in an electrolyte solution.

Here, the electrolyte is composed of a lithium salt and an organic solvent, all of which are commonly used in lithium secondary batteries can be used. The organic solvent is propylene carbonate (PC), ethylene carbonate (EC), γ-butyrolactone, 1,3-dioxolane, dimethoxyethane, dimethyl carbonate (DMC), methylethyl carbonate (MEC) And at least one solvent selected from diethyl carbonate (DEC), tetrahydrofuran (THF), dimethyl sulfoxide and polyethylene glycol dimethyl ether. And the content of the solvent is the usual level used in the lithium secondary battery. Lithium salts include lithium perchlorate (LiClO ₄ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ) and lithium bistrifluoromethanesulfonyl At least one ionic lithium salt selected from the group consisting of amides (LiN (CF ₃ SO ₂ ) ₂ ) is used and its content is at the usual level used in lithium secondary batteries.

In the lithium secondary battery manufactured according to the above-described process, the plasticizer is contained in the electrode and the separator so that the plasticity can be sufficiently provided between the both electrodes and the separator film member, and the lamination between the electrode and the separator is very excellent. It is done easily. In addition, the adhesion between the layers is improved, thereby reducing the interface resistance.

On the other hand, prior to the injection of the electrolyte, it is necessary to first go through the process of drying in a vacuum oven maintained at a high temperature. The reason is to completely remove the organic solvent remaining in the organic solvent used in the extraction and removal process of the plasticizer. However, in the present invention, it is not necessary to remove the plasticizer through the extraction process using the organic solvent, so that the drying process can be skipped and the electrolyte can be directly injected, thereby reducing the manufacturing time.

Hereinafter, the present invention will be described in detail with reference to the following examples, but the present invention is not limited to the following examples.

<Example 1>

50 g of Kinar 2801 (Elf-atochem) was added to 600 ml of acetone, and the mixture was dissolved in a ball mill for 2 hours. 410 g of LiCoO ₂ and 40 g of Superpie were added to the mixture, which was then mixed for 5 hours. Then 200 mL of ethanol was added to the mixture and mixed for 24 hours to form a cathode active material composition.

The cathode active material composition was cast on a PET pole plate using a 320 μm gap doctor blade and dried at 30 ° C. to form a 45 μm thick cathode active material layer. The active material layer was peeled off from the PET electrode plate, cut into a size of 14.8 × 11.8 cm ² , and then laminated on the pretreated aluminum expanded metal, which was punched out to form a unit cathode electrode plate. The weight of the cathode electrode plate obtained at this time was about 0.41 g.

Separately, 65 g of Kinar 2801 (Elf-atochem) was added to 600 ml of acetone, followed by mixing for 2 hours in a ball mill for dissolution. 415 g of mesocarbon fiber (MCF) and 20 g of super blood were added to the mixture, which was then mixed for 5 hours. 200 mL of ethanol was then added to the mixture and mixed for 24 hours to form an anode active material composition.

The anode active material composition was cast on a PET electrode plate using a 320 μm gap doctor blade and dried at 30 ° C. to form a 45 μm thick anode active material layer. The active material layer was peeled off from the PET electrode plate, cut into a size of 14.8 × 11.8 cm ² , and then laminated on the pretreated copper expanded metal, which was punched out to form a unit anode electrode plate. The weight of the anode plate obtained at this time was about 0.46 g.

60 g of Kinar 2801 (Elf-atochem), 80 g of propylene carbonate, and 600 ml of acetone were mixed in a ball mill for 2 hours. 40 g of silica was added thereto and sufficiently mixed for 24 hours to form a composition for forming a separator.

The composition for forming a separator was cast on a PET electrode plate using a doctor blade having a 320 μm gap and dried at 30 ° C. The separator film was separated from the PET electrode plate.

The cathode plate, the anode plate, and the separator obtained according to the above process were laminated in the order of cathode / separator / anode / separator / cathode to form a bicell structure. An aluminum tab and a copper tab were welded to the bicell structure thus obtained, followed by impregnation of an electrolyte solution (Merck, 1.5M LiPF ₆ in EC: DMC: DEC = 3: 3: 4) for 3 hours to complete a lithium secondary battery. It was.

<Example 2>

A lithium secondary battery was completed in the same manner as in Example 1, except that dimethyl carbonate was used instead of propylene carbonate in the separator forming composition.

<Example 3>

A lithium secondary battery was completed in the same manner as in Example 1, except that diethoxyethane was used instead of propylene carbonate in the composition for forming a separator.

<Example 4>

60 g of Kinar 2801 (Elf-atochem), 80 g of propylene carbonate, and 600 ml of acetone were mixed and dissolved in a ball mill for 2 hours. 410 g of LiCoO ₂ and 40 g of Superpie were added to the mixture, which was then mixed for 24 hours to form a cathode active material composition.

The cathode active material composition was cast on a PET electrode plate using a 320 μm gap doctor blade and dried at 30 ° C. to form a cathode active material layer having a thickness of 45 μm, and the active material layer was peeled off from the PET electrode plate, which was 14.8 × 11.8 cm. ^After cutting to size ² , it was laminated on the pretreated aluminum expanded metal and punched out to form a unit cathode electrode plate. The weight of the cathode electrode plate obtained at this time was about 0.41 g.

Separately, 60 g of Kinar 2801 (Elf-atochem), 80 g of propylene carbonate, and 600 ml of acetone were mixed and dissolved in a ball mill for 2 hours. 415 g of mesocarbon fiber (MCF) and 20 g of superpies were added to the mixture, which was then mixed for 24 hours to form an anode active material composition.

The anode active material composition was cast on a PET electrode plate using a 320 μm gap doctor blade and dried at 30 ° C. to form an anode active material layer having a thickness of 45 μm, and the active material layer was peeled off from the PET electrode plate, which was 14.8 × 11.8 cm. ^After cutting to size ² , it was laminated onto the pretreated copper expanded metal and punched out to make a unit anode electrode plate. The weight of the anode plate obtained at this time was about 0.46 g.

60 g of Kinar 2801 (Elf-atochem), 80 g of propylene carbonate, and 600 ml of acetone were mixed in a ball mill for 2 hours. 40 g of silica was added thereto and sufficiently mixed for 24 hours to form a composition for forming a separator.

The composition for forming a separator was cast on a PET electrode plate using a doctor blade having a 320 μm gap and dried at 30 ° C. A 45 µm thick separator film was separated from the PET electrode plate.

The cathode plate, the anode plate, and the separator obtained according to the above process were laminated in the order of cathode / separator / anode / separator / cathode to form a bicell structure. An aluminum tab and a copper tab were welded to the bicell structure thus obtained, and then a lithium secondary battery was completed by impregnating an electrolytic solution (Merck, 1.5M LiPF ₆ in EC: DMC: DEC = 3: 3: 4).

Example 5

A lithium secondary battery was completed in the same manner as in Example 4 except that diethyl carbonate was used instead of propylene carbonate in the composition for forming a separator.

<Example 6>

A lithium secondary battery was completed in the same manner as in Example 4, except that diethoxyethane was used instead of propylene carbonate in the composition for forming a separator.

Comparative Example

65 g of mesocarbon fiber (MCF) (Petoca Corporation), 10 g of Kynar 2801 (Kdnar 2801) (22 wt% copolymer of VdF 88 wt% / HFP), 3.25 g of Super-P (MMM.Carbon), dibutyl phthalate (DBP) An anode active material composition was prepared by mixing 21.75 g of Aldrich and 150 ml of acetone (Samjeon Chemical).

The anode active material composition was coated on a Cu current collector and then dried at (35) ° C. to prepare a porous anode.

Separately, 65 g of LiCoO ₂ (Nippon Chemical), 10 g of Kynar 2801 (22 wt% copolymer of VdF 88 wt% / HFP), 6.5 g of Super-P (MMM.Carbon), 18.5 g of DBP, and acetone ( Samjeon Chemical) 150ml was mixed to prepare a cathode active material composition.

The cathode active material composition was coated on an Al current collector and then dried at (35) ° C. to prepare a porous cathode.

Kynar 2801 (VdF 88wt% / HFP 22wt% copolymer) 32g, silica (Carbot) 26g, DBP (Aldrich) 42g and acetone (trielectric chemistry) 200ml mixed to form a composition for forming Was prepared. The separator composition was cast on a PET pole plate, dried at 35 ° C., and a film was removed from the PET pole plate to form a porous separator.

Subsequently, separators were placed on both sides of the anode and laminated, and the cathodes were laminated on the separator and brought into close contact with each other, and then cut into a predetermined size to produce a bicell.

Thereafter, the obtained cell was impregnated with ether to extract and remove DBP from the bicell structure.

Thereafter, the resultant obtained by the above process was dried for 1 hour at a temperature of 50 ℃ under vacuum conditions, and then put into a plastic bag that can be sealed by heat. Thereafter, an electrolyte solution (1.15M LiPF ₆ in EC: DMC: DEC = 3: 3: 4) was injected into the resultant under an argon gas atmosphere to complete a lithium secondary battery.

In the comparative example, dibutyl phthalate should be extracted and removed, and then dried in a high temperature oven. However, according to Examples 1-6, the plasticizer extraction process is unnecessary and electrolyte solution can be directly injected without drying. Manufacturing time was reduced.

In the lithium secondary battery prepared according to Example 1, after 3 hours, 10 hours after the injection of the electrolyte, each of when formed (formation) to 1 / 10C, charged and discharged at 1 / 2C Reversible capacity was investigated. The results are shown in Table 1 below.

Elapsed time after electrolyte injection 1 / 10C Mars 1 / 2C Mars Charge capacity (mAh) Discharge Capacity (mAh) Reversible Capacity (%) Charge capacity (mAh) Discharge Capacity (mAh) Reversible Capacity (%) 3 151 122.5 81.1 121 111.5 92.15 10 159 126 79.2 128.5 118.2 91.98

As can be seen in Table 1, it was confirmed that the lithium secondary battery prepared according to Example 1 has excellent reversible capacity characteristics and particularly high rate characteristics. In addition, as a result of examining the reversible capacity of the lithium secondary battery prepared according to Example 2-6, the results were almost similar to those of Example 1.

In addition, in the lithium secondary battery according to Example 1-6, the interfacial resistance between the electrode and the separator was investigated.

As a result, the battery of Example 1-6 was confirmed that plasticity is imparted to the electrode and / or separators compared to the case of the comparative example, the lamination is made more smoothly, the interfacial resistance between each layer is reduced.

In the lithium secondary battery according to the present invention, plasticity is imparted to the electrode and the separator so that the lamination process is smooth. As a result, a battery structure having reduced interface resistance between the electrode and each layer of the separator can be obtained, and the electrolyte can be directly injected without going through the process of drying the battery structure, thereby reducing the manufacturing time. In addition, since the extraction process of the organic solvent for removing the plasticizer is unnecessary, the manufacturing process is simplified. In addition, since the content of the plasticizer is small, the relative content of the electrode active material is increased to obtain the effect of improving the discharge capacity characteristics.

Claims (6)

A cathode and an anode in which pores are formed by forming an electrode active material layer on each current collector using an electrode active material composition containing an electrode active material, a conductive agent, a binder, acetone, and ethanol to remove the ethanol; A polymer resin, at least one plasticizer selected from 5 to 60 parts by weight of dialkyl carbonate, alkylene carbonate, and dialkoxy ethane based on 100 parts by weight of the polymer resin, and 10 to 50 parts by weight of inorganic filler, wherein the pores are formed. I have a separator that is not A lithium secondary battery, wherein the separator is laminated between the cathode and the anode. A cathode and an anode including at least one plasticizer selected from 5 to 60 parts by weight of dialkyl carbonate, alkylene carbonate, and dialkoxy ethane based on 100 parts by weight of the electrode active material, the conductive agent, the binder, and the electrode active material. , A polymer resin, one plasticizer selected from 5 to 60 parts by weight of dialkyl carbonate, alkylene carbonate, and dialkoxy ethane based on 100 parts by weight of the polymer resin, and 10 to 50 parts by weight of inorganic filler, wherein the pores are formed. I have a separator that is not A lithium secondary battery, wherein the separator is laminated between the cathode and the anode. The plasticizer of claim 1 or 2, wherein the plasticizer is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, dipropyl carbonate, diethyl carbonate, diethoxyethane, dimethoxyethane and mixtures thereof. Lithium secondary battery. The lithium secondary battery according to claim 1 or 2, wherein the inorganic filler of the separator is at least one selected from the group consisting of alumina, silica, and kaolin. 3. The binder of the cathode and the anode and the polymer resin according to claim 1 or 2, wherein the vinylidene fluoride-hexafluoropropylene copolymer, polyvinylidene fluoride. Lithium secondary battery, characterized in that at least one selected from the group consisting of polyacrylonitrile and polymethyl methacrylate. The method of claim 1, wherein the electrode active material layer, It is formed by directly coating and drying the electrode active material composition on the current collector, or by casting and drying the electrode active material composition on a separate support and then laminating the active material layer film obtained by peeling from the support on the current collector. Lithium secondary battery, characterized in that.