KR100669338B1 - Negative electrode for rechargeable lithium battery and rechargeable lithium battery comprising same - Google Patents

Abstract

Provided is an anode for a lithium secondary battery, which shows a cushioning effect against variations in volume of an anode active material, and thus improves the service life of a lithium secondary battery. The anode(1) for a lithium secondary battery comprises: a collector(2) and an anode active material layer(3) comprising a material capable of reacting reversibly with lithium to form a compound and formed on the collector. In the anode, the collector comprises: a polymer film support(4) having elasticity, a thickness of 5-10 micrometers and an average surface roughness (Ra) of 350-1000nm; and a metal layer(5,5') formed on one or both surfaces of the polymer film support and having a thickness of 300 nm-2 micrometers.

Description

A negative electrode for a lithium secondary battery, and a lithium secondary battery including the same {NEGATIVE ELECTRODE FOR RECHARGEABLE LITHIUM BATTERY AND RECHARGEABLE LITHIUM BATTERY COMPRISING SAME}

1 is a cross-sectional view of a cathode according to an embodiment of the present invention.

2 is a cross-sectional view of a lithium secondary battery according to one embodiment of the present invention.

[Description of Symbols for Main Parts of Drawing]

1: cathode 2: current collector

3: negative electrode active material layer 4: polymer film support

5, 5 ': metal layer 10: lithium secondary battery

11: anode 12: cathode

13: Separator 14: Electrode Assembly

15: Case 16: Cap Plate

17: gasket

[Industrial use]

The present invention relates to a negative electrode for a lithium secondary battery and a lithium secondary battery including the same, and more particularly, to include a lithium secondary battery negative electrode having an excellent buffering effect on volume change of a negative electrode active material and improving battery life characteristics. It relates to a lithium secondary battery.

[Prior art]

Lithium secondary batteries, which are in the spotlight as power sources of recent portable small electronic devices, exhibit high energy density by showing a discharge voltage that is twice as high as that of a battery using an alkaline aqueous solution using an organic electrolyte solution.

As a cathode active material of a lithium secondary battery, an oxide composed of lithium and a transition metal having a structure capable of intercalating lithium, such as LiCoO ₂ , LiMn ₂ O ₄ , and LiNi _{1- x} Co _x O ₂ (0 <X <1) Was mainly used.

Lithium metal was initially used as a negative electrode active material. However, due to a problem of dendrites occurring and a very short lifespan, various types of carbon-based carbonaceous materials including artificial graphite, natural graphite, and hard carbon, which can be inserted / desorbed of lithium, have recently been used. The material is being used. However, the carbon-based anode active material can solve the problem of dendrites and has excellent voltage flatness and good life characteristics at low potential, but due to high reactivity with the organic electrolyte and low diffusion rate of lithium in the material, power ( There are problems such as power characteristics, initial irreversible control, and electrode swelling during charging and discharging.

Accordingly, researches for using lithium alloy as a negative electrode active material to solve the problem of dendrites have a long life. U. S. Patent No. 6,051, 340 describes a negative electrode comprising a metal that is not alloyed with lithium and a metal that is alloyed with lithium. In this patent, the metal that is not alloyed with lithium serves as a current collector, and the metal that is alloyed with lithium forms an alloy with lithium ions taken out of the anode during charging, and the alloy serves as a negative electrode active material, The negative electrode contains lithium during charging. However, even with the lithium alloy described above, it was difficult to obtain satisfactory battery characteristics.

In addition, silicon, tin, or a compound thereof has also been studied as a material that can replace the carbon-based material used as the negative electrode active material. However, the silicon or tin has a problem of large irreversible capacity, and in particular, silicon has a problem of severe shrinkage and expansion as the charging and discharging cycle progresses, so that the negative electrode active material is dropped, thereby deteriorating the life characteristics of the lithium secondary battery. The tin oxide proposed by Japan's Fujifilm Co., Ltd. was spotlighted as a new material to replace the carbon-based negative electrode active material, but the initial coulombic efficiency was lowered to 30% or less, and the lithium-tin alloy of lithium was formed by continuous charging and discharging. Due to the reduced capacity and low life characteristics, it is not practical.

The positive electrode and the negative electrode of the lithium secondary battery are prepared by mixing such an active material, a binder, and optionally a conductive material to prepare a slurry type composition, and applying the composition to a current collector. At this time, aluminum is mainly used for the positive electrode as the current collector, and copper is mainly used for the negative electrode.

Recently, studies for further improving the energy density of lithium secondary batteries have been conducted.

An object of the present invention is to provide a negative electrode for a lithium secondary battery that is excellent in buffering effect on volume change of the negative electrode active material.

Still another object of the present invention is to provide a lithium secondary battery including the negative electrode for a lithium secondary battery and having excellent energy density and life characteristics.

In order to achieve the above object, the present invention includes a negative electrode active material layer formed on a current collector and the current collector, including a material capable of reversibly reacting with lithium to form a compound, the current collector has elasticity It provides a negative electrode for a lithium secondary battery that includes a polymer film support having a thickness of 5㎛ 10㎛ and a metal layer formed on one or both surfaces of the polymer film support and having a thickness of 300nm to 2㎛.

The present invention also provides a lithium secondary battery including the negative electrode, the positive electrode including the positive electrode active material and the electrolyte.

Hereinafter, the present invention will be described in more detail.

In a lithium secondary battery, active materials in the electrode contract and expand as charge and discharge proceed. In particular, the volume change of the silicon-based negative electrode active material is severe. Such a volume change of the active material has a problem of causing a decrease in the life characteristics of the lithium secondary battery.

On the other hand, in the present invention, instead of the usual metal current collector used in the production of the electrode plate of the lithium ion secondary battery, a polymer film having elasticity is used to exhibit a buffering effect against the volume change of the active material due to charge and discharge. By optimizing the thickness of the polymer film and the metal layer formed on the polymer film, the cycle life characteristics of the battery of the lithium secondary battery could be improved.

That is, the negative electrode for lithium secondary batteries which concerns on one Embodiment of this invention,

A negative electrode active material layer formed on a current collector and a current collector, and including a material capable of reversibly reacting with lithium to form a compound,

The current collector has elasticity and has a polymer film support having a thickness of 5 μm to 10 μm; And

It is formed on one side or both sides of the polymer film support, and includes a metal layer having a thickness of 300nm to 2㎛.

1 is a cross-sectional view of a negative electrode for a lithium secondary battery according to one embodiment of the present invention. Referring to FIG. 1, the lithium secondary battery negative electrode 1 according to the exemplary embodiment of the present invention is formed on the current collector 2 and the current collector 2, and reversibly reacts with lithium to form a compound. And a negative electrode active material layer 3 including a material capable of forming the current collector, wherein the current collector includes elastic polymer film support 4 and metal layers 5 and 5 'formed on one or both surfaces of the polymer film support 4. ).

In the current collector according to the embodiment of the present invention, the polymer film support and the metal layer are used to properly adjust the thickness in consideration of the thickness ratio of each other, the polymer film support and the metal layer are 5㎛ to 10㎛, respectively 300nm It is preferred to have a thickness of 2 to 2 µm, more preferably 5 to 8 µm, and 500 nm to 1 µm.

In the case of the polymer film support, if the thickness is less than 5㎛ has a lot of manufacturing cost in the film production and there is a lot of constraints in handling during work, if the thickness exceeds 10㎛ to use the Cu metal film currently used as a current collector The use of thicker films is undesirable in terms of energy density. In addition, in the case of the metal layer, the thickness is less than 300nm shows bad characteristics in terms of electrical conductivity, and when the thickness exceeds 2 μm, there is a problem in that the metal layer is peeled off from the polymer support after manufacture, which is difficult to use.

The polymer film support has a buffering effect against shrinkage expansion of the active material due to charging and discharging, and preferably has elasticity. In addition, the polymer film support has a form of embossing on the surface, preferably has an average surface roughness (Ra) of 350 to 1000 nm, more preferably 500 to 1000 nm. When the average surface roughness is less than 350 nm, the negative electrode active material layer may be peeled off from the current collector after charging and discharging, thereby deteriorating the life characteristics. In addition, when the average surface roughness exceeds 1000nm, it is difficult to make the plating thickness uniform because the metal layer is made inhomogeneously by the point when metal plating on the polymer film support. Therefore, the use of a polymer film support having an average surface roughness within the above-described range can improve the adhesion with the negative electrode active material, and also play a great support role in adhesion with the current collector due to expansion of the negative electrode active material during charging and discharging. It is possible to obtain good cycle characteristics.

The surface roughness of the polymer film support can be appropriately adjusted according to the coating treatment method, or a polymer film having a range of average surface roughness can be purchased and used.

The polymer that can be used as the polymer film support may be used without particular limitation as long as it has elasticity. Specifically, polyethylene terephthalate, polyimide, polytetrafluoroethylene, polyethylene naphthalate, polypropylene, polyethylene, polyester, poly Preference is given to using at least one selected from the group consisting of vinylidene fluoride, polysulfone and mixtures thereof, more preferably at least one selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate and mixtures thereof Can be used.

In addition, the polymer film support may further include a silicon-containing release agent layer. The silicone-containing release agent layer is formed on the side where the metal layer of the polymer film support is not formed to prevent direct contact between the protective film and the polymer film support when the electrode plate is manufactured or when the manufactured electrode plate is wound or transported during storage. Can be.

The silicon-containing release agent layer may be formed of a general coating method such as a roll coating, spray coating, gravure coating using a silicon-containing compound of formula (1).

[Formula 1]

(In Formula 1, R ₁ , R ₂ , R ₃ and R ₄ are linear or branched alkyl, cycloalkyl, alkenyl, aryl, aralkyl, halogenated alkyl, halogenated aryl, halogenated aralkyl, phenyl, mercaptan, respectively. , Methacrylate, acrylate, epoxy or vinyl ether, the alkyl is C ₁ to C ₁₈ , the cycloalkyl is C ₃ to C ₁₈ , the alkenyl is C ₂ to C ₁₈ , the aryl and the aralkyl are C ₆ to C _{18 have} a carbon number, n and m may be different or the same, and is an integer from 1 to 100,000.)

The metal layer may be formed on one side or both sides of the polymer film support, and preferably include at least one metal selected from the group consisting of Ni, Ti, and Cu, and more preferably Cu or Ni.

As described above, the current collector according to an embodiment of the present invention comprising the polymer film support having elasticity and a metal layer formed on one or both surfaces of the polymer film support with an appropriate thickness includes a current collector of a conventional metal base and Alternatively, the energy density per weight can be improved by using a polymer film as a support.

The negative electrode active material layer formed on the current collector includes at least one material selected from the group consisting of a material capable of reversibly forming a compound with lithium, and more preferably Al, Si, Sn, Ag, Bi, Mg , Zn, In, Ge, Pb, Ti and the like, and a compound containing these elements, or a compound of the above elements and the elements containing them, and at least one selected from the group consisting of a composite material of carbon and graphite materials can do.

The negative electrode for a rechargeable lithium battery according to one embodiment of the present invention may be manufactured by a manufacturing method including forming a metal layer on one or both surfaces of a polymer film support and further forming a negative electrode active material layer on the metal layer.

First, a polymer film support having a proper surface roughness is prepared, and metal layers are formed on one or both surfaces of the polymer film support.

The polymer film support is the same as described above, and the method of forming the surface roughness of the polymer film support may also use a conventional coating treatment method as described above, or a polymer film having a range of average surface roughness It can also be purchased and used.

Next, the metal layer forming method may use any of a general liquid coating process or a deposition process.

In the case of performing the liquid coating step, a metal powder is added to the solvent to prepare a metal-containing composition, and the step of coating the composition on a polymer film support. As the coating process, all the general liquid coating processes can be used, and typical examples include knife coating, direct roll coating, reverse roll coating, gravure roll coating, and gap coating ( gap coating, spray coating, slot die coating, or tape casting. The metal included in the metal layer is the same as described above. In addition, the solvent may be used without particular limitation as long as it has a low boiling point, is easily removed, has low reactivity with metals, and leaves no residue after drying. For example, acetonitrile, acetone, acetone, tetrahydrofuran, dimethyl formamide, N-methyl pyrrolidinone, and the like can be used.

In addition, the deposition process may be thermal evaporation, sputtering, ion-beam-assisted deposition or chemical vapor deposition.

Then, the negative electrode active material layer is coated on the polymer film support on which the metal layer is formed and dried to prepare a negative electrode. The negative active material may use the same active material as described above, and the active material layer forming method uses a general slurry coating process.

The negative electrode for a lithium secondary battery having the above structure exhibits a buffering effect against the volume change of the active material due to charging and discharging, thereby improving the life characteristics of the battery of the lithium secondary battery.

According to an embodiment of the present invention, the negative electrode; A positive electrode including a positive electrode active material; And it provides a lithium secondary battery comprising an electrolyte.

The lithium secondary battery may be classified into a lithium ion battery, a lithium ion polymer battery, and a lithium polymer battery according to the type of separator and electrolyte used, and may be classified into a cylindrical shape, a square shape, a coin type, a pouch type, and the like, Depending on the size, it can be divided into bulk type and thin film type. Since the structure and manufacturing method of these batteries are well known in the art, detailed description thereof will be omitted.

2 is a cross-sectional view showing a rectangular lithium secondary battery according to an embodiment of the present invention. Referring to FIG. 2, the prismatic lithium ion battery 10 includes an electrode assembly including a positive electrode 11, a negative electrode 12, and a separator 13 between the positive electrode 11 and the negative electrode 12. (14) is put into the case 15, and then electrolyte is injected into the upper part of the case 15, and it is assembled by sealing it with the cap plate 16 and the gasket 17.

The cathode is the same as described above.

The positive electrode may include a reversible intercalation / deintercalation compound (lithiated intercalation compound) of lithium as a positive electrode active material, or a material capable of forming a lithium-containing compound by reversibly reacting with lithium. It may include, preferably at least one selected from cobalt, manganese, nickel, and may include at least one of a composite oxide with lithium. More preferably, the lithium containing compounds described below may be preferably included:

Li _x Mn _{1 - y} M _y A ₂ (1)

Li _x Mn _{1 - y} M _y O _{2 - z} X _z (2)

Li _x Mn ₂ O _{4 - z} X _z (3)

Li _x Mn _{2 - y} M _y A ₄ (4)

Li _x Co _{1 - y} M _y A ₂ (5)

Li _x Co _{1 - y} O _{2 - z} X _z (6)

Li_xNi_{One - y}M_yA₂ (7)

Li _x Ni _{1 - y} O _{2 - z} X _z (8)

Li _x Ni _{1 - y} Co _y O _{2 - z} X _z (9)

Li _x Ni _{1 -y- z} Co _y M _z A _α (10)

Li _x Ni _{1 -y- z} Co _y M _z O _{2 -α} X _α (11)

Li _x Ni _{1 -y- z} Mn _y M _z A _α (12)

Li _x Ni _{1 -y- z} Mn _y M _z O _{2 -α} X _α (13)

Wherein 0.9 ≦ x ≦ 1.1, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 0.5, 0 ≦ α ≦ 2, and M is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V or rare earth At least one element selected from the group consisting of elements, A is an element selected from the group consisting of O, F, S and P, and X is F, S or P.)

In addition to the sulfur-based material used as the positive active material is elemental sulfur, Li ₂ S _n (n≥1), dissolved in the cache solrayiteu _{(catholyte) Li 2 S n (} n≥1), an organic sulfur compound, a carbon-sulfur polymer ((C ₂ S _x ) _n : x = 2.5 to 50, n ≧ 2) and the like.

The separator may exist between the positive electrode and the negative electrode according to the type of the lithium secondary battery. As the separator, polyethylene, polypropylene, polyvinylidene fluoride or two or more multilayer films thereof may be used, and polyethylene / polypropylene two-layer separator, polyethylene / polypropylene / polyethylene three-layer separator, polypropylene / polyethylene / poly It goes without saying that a mixed multilayer film such as a propylene three-layer separator can be used.

As the electrolyte charged in the lithium secondary battery, a non-aqueous electrolyte or a known solid electrolyte may be used.

The non-aqueous electrolyte is prepared by dissolving a lithium salt in a non-aqueous organic solvent. The non-aqueous organic solvent serves as a medium through which ions involved in the electrochemical reaction of the cell can move. As the non-aqueous organic solvent, benzene, toluene, fluorobenzene, 1,2-difluorobenzene, 1,3-difluorobenzene, 1,4-difluorobenzene, 1,2,3-trifluoro Robenzene, 1,2,4-trifluorobenzene, chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,3-trichlorobenzene, 1, 2,4-trichlorobenzene, iodobenzene, 1,2-dioodobenzene, 1,3-dioodobenzene, 1,4-dioiobenzene, 1,2,3-triiodobenzene, 1,2 , 4-triiodobenzene, fluorotoluene, 1,2-difluorotoluene, 1,3-difluorotoluene, 1,4-difluorotoluene, 1,2,3-trifluorotoluene, 1,2,4-trifluorotoluene, chlorotoluene, 1,2-dichlorotoluene, 1,3-dichlorotoluene, 1,4-dichlorotoluene, 1,2,3-trichlorotoluene, 1,2,4 -Trichlorotoluene, iodotoluene, 1,2-dioodotoluene, 1,3-dioodotoluene, 1,4-dioodotoluene, 1,2,3 -Triiodotoluene, 1,2,4-triiodotoluene, R-CN (wherein R is a straight-chain, branched, or cyclic C2-C50 hydrocarbon group, and this hydrocarbon group is a double bond , Aromatic ring, or ether bond), dimethoxyformamide, methyl acetate, xylene, cyclohexane, tetrahydrofuran, 2-methyltetrahydrofuran, cyclohexanone, ethanol, isopropyl alcohol, dimethyl Carbonate, ethylmethyl carbonate, diethyl carbonate, methylpropyl carbonate, methyl propionate, ethyl propionate, methyl acetate, ethyl acetate, propyl acetate, dimethoxyethane, 1,3-dioxolane, diglyme, tetraglyme , At least one mixed organic solvent selected from the group consisting of ethylene carbonate, propylene carbonate, γ-butyrolactone and sulfolane .

The lithium salt is a substance that dissolves in an organic solvent and acts as a source of lithium ions in the battery to enable the operation of a basic lithium ion secondary battery and to promote the movement of lithium ions between the positive electrode and the negative electrode. Representative examples of the lithium salt include lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroazate (LiAsF ₆ ), lithium perchlorate (LiClO ₄ ), and lithium trifluoromethanesulfo Nate (CF ₃ SO ₃ Li), lithium bis (trifluoromethyl) sulfonimide (LiN (SO ₂ CF ₃ ) ₂ ) and lithium bis (perfluoroethylsulfonyl) imide (LiN (SO ₂ C ₂₎ One or two or more mixtures selected from the group consisting of F ₅ ) ₂ ) can be used. The lithium salt is preferably present at a concentration of 0.1 to 2.0M. When the concentration of the lithium salt is less than 0.1M, the conductivity of the electrolyte is lowered, the performance of the electrolyte is lowered, and when the concentration exceeds 2.0M, there is a problem that the mobility of lithium ions is reduced by increasing the viscosity of the electrolyte.

The solid electrolyte may be a polyethylene oxide polymer electrolyte or a polymer electrolyte containing at least one polyorganosiloxane side chain or polyoxyalkylene side chain, Li ₂ S-SiS ₂ , Li ₂ S-GeS ₂ , Li ₂ SP ₂ S ₅ , Li Sulfide electrolytes such as ₂ SB ₂ S ₃ , inorganic compound electrolytes such as Li ₂ S-SiS ₂ -Li ₃ PO ₄ , Li ₂ S-SiS ₂ -Li ₃ SO _4, and the like can be preferably used.

Hereinafter, preferred examples and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention and the present invention is not limited to the following examples.

Comparative example  1: Preparation of Cathode

The slurry was prepared using a solvent of n-methyl-2-pyrrolidone (NMP) in a mixed composition in which the ratio of the silicon negative electrode active material, the conductive material, and the polyvinyl difluoride (PVdF) binder was 80:10:10 (wt%). After the preparation, it was coated with a doctor blade method on a 10 μm thick copper (Cu) current collector (surface roughness: 350 nm). Then, dried at 120 ° C. in a hot air oven for 30 minutes to volatilize NMP to prepare a plate. The negative electrode was manufactured by punching the produced electrode plate in a circular shape having a diameter of 13 mm.

Example  1: Preparation of Cathode

A negative electrode for a lithium secondary battery was manufactured in the same manner as in Comparative Example 1 except that copper was deposited on both surfaces of a polyethylene terephthalate film having an average surface roughness of 447 nm (0.447 μm) using a tungsten boat as the negative electrode current collector. Was prepared. At this time, the thickness of the polymer film support and the copper layer was 8 μm and 2 μm (the front and rear metal layers were 1 μm each).

Comparative example  2 and Example  2 to 4: preparation of negative electrode

A negative electrode for a lithium secondary battery was manufactured in the same manner as in Comparative Example 1, except that the thickness of the polymer film and the metal layer and the average surface roughness of the polymer film in the negative electrode current collector were variously changed as shown in Table 1 below. .

Polymer film support thickness Metal layer thickness Average Surface Roughness of Polymer Film Supports Comparative Example 1 0 μm 10 μm 350 nm Comparative Example 2 6 μm 100 nm 500 nm Example 1 8㎛ 2 μm 447 nm Example 2 8㎛ 1 μm 1000 nm Example 3 8㎛ 1 μm 100 nm Example 4 6 μm 1 μm 500 nm

[Manufacture of test cell for charge / discharge test]

A separator made of a porous polypropylene film was formed between the working electrode and the counter electrode by using the cathodes of Examples 1 to 4 and Comparative Examples 1 and 2 as the working electrodes, respectively, and a metal lithium foil cut into a circular shape having the same diameter as the counter electrode. The concentration of LiPF ₆ was 1.3 mol / L in a mixed solvent of propylene carbonate (PC), diethyl carbonate (DEC) and ethylene carbonate (EC) (PC: DEC: EC = 1: 1: 1). Coin-type half cells were prepared using those dissolved as much as possible.

The coin-type half cell prepared by the above method was charged at 0.005 V or 1000 mAh / g at the first charge and discharged to 1.0 V at the time of discharge. At this time, the C-rate was 0.2C ↔ 0.2C. From the second cycle, the charge cut-off was charged to 0.005V to the same potential as the first cycle, and discharged to 1.0V. At this time, C-rate was 0.2C ↔ 0.2C as in the first charge and discharge. The cycle life shows the capacity after performing 50 cycles of charging / discharging at 0.2C as a percentage of the initial capacity.

Initial charge capacity [mAh / g] Initial Discharge Capacity [mAh / g] Initial Efficiency [%] life span [%] Comparative Example 1 999.9 757.3 75.7 42.5 Comparative Example 2 1000.0 758.0 75.8 15.6 Example 1 999.9 755.7 75.6 65.6 Example 2 1000.0 756.6 75.7 85.8 Example 3 999.9 756.5 75.7 23.7 Example 4 999.9 757.3 75.7 82.6

As shown in Table 2, in Examples 1, 2 and 4 including the current collector consisting of a polymer film support and a metal layer, it was confirmed that the life characteristics are significantly superior to Comparative Example 1 using Cu foil as a current collector. . In addition, although the current collector is composed of a polymer film support and a metal layer, as in Examples 1, 2, and 4, in Comparative Example 2, where the thickness of the metal layer is too small outside the thickness range of the present invention, the life characteristics of the battery are rather poor. I could confirm it. From this, it can be seen that it is important for the current collector to include a polymer film support and a metal layer having a suitable thickness in order to obtain excellent life characteristics.

In addition, in Example 3, the current collector is composed of a polymer film support and a metal layer included in the thickness range of the present invention, but the effect of the life characteristics obtained is insignificant. This is because the average surface roughness of the polymer film support included in Example 3 is too small, from which it can be confirmed that the average surface roughness of the polymer film support also affects the cycle life characteristics.

The negative electrode for lithium secondary batteries of the present invention exhibits a buffering effect against the volume change of the active material due to charge and discharge, and can also improve the life characteristics of the battery of the lithium secondary battery.

Claims (8)

A negative electrode active material layer formed on a current collector and a current collector, and including a material capable of reversibly reacting with lithium to form a compound, The current collector is elastic and has a thickness of 5 μm to 10 μm, and an average film roughness Ra of 350 nm to 1000 nm; And The negative electrode for a lithium secondary battery is formed on one side or both sides of the polymer film support and comprises a metal layer having a thickness of 300nm to 2㎛. The method of claim 1, The polymer film support is a negative electrode for a lithium secondary battery having an embossed surface. delete The method of claim 1, The polymer film support is selected from the group consisting of polyethylene terephthalate, polyimide, polytetrafluoroethylene, polyethylene naphthalate, polypropylene, polyethylene, polyester, polyvinylidene fluoride, polysulfone, and mixtures thereof Cathode for lithium secondary battery. The method of claim 1, The polymer film support further comprises a silicon-containing release agent layer negative electrode for a lithium secondary battery. The method of claim 1, The metal layer is a negative electrode for a lithium secondary battery comprising one selected from the group consisting of Ni, Ti, Cu and combinations thereof. The method of claim 1, The negative electrode active material layer is an element containing Al, Si, Sn, Ag, Bi, Mg, Zn, In, Ge, Pb, Ti and a compound containing these elements; Complexes of the above elements or compounds containing these elements with carbon and graphite materials; And negative electrode for a lithium secondary battery comprising a selected from the group consisting of these. Claims 1, 2 and 4 according to any one of the negative electrode; A positive electrode including a positive electrode active material; And Electrolyte Lithium secondary battery comprising a.

Images