KR102543243B1 - Lithium Metal Electrode and Method for Preparing the Same - Google Patents

Abstract

The present invention relates to a lithium electrode and a manufacturing method thereof. More specifically, a highly heat-resistant porous substrate serving as a separator is integrally formed with a lithium electrode, and thus has excellent stability during a lithium electrode manufacturing process performed at a high temperature, thereby simplifying the manufacturing process and improving process efficiency. The size of the pores formed in the substrate is uniform and the porosity is high, and lithium ion conductivity can be improved, and when applied to a battery, short circuit due to shrinkage of the separator can be prevented.

Description

Lithium electrode and its manufacturing method {Lithium Metal Electrode and Method for Preparing the Same}

The present invention relates to a lithium electrode in which a separator is integrally formed and a method for manufacturing such a separator-integrated lithium electrode.

Until recently, there has been considerable interest in developing high energy density batteries using lithium as the negative electrode. For example, compared to other electrochemical systems with lithium intercalated carbon negative electrodes, and nickel or cadmium electrodes, where the presence of non-electroactive materials increases the weight and volume of the negative electrode, thereby reducing the energy density of the cell, lithium metal Since silver has characteristics of low weight and high capacity, it has attracted great interest as an anode active material for electrochemical cells. A lithium metal negative electrode or a negative electrode mainly containing lithium metal provides an opportunity to construct a battery that is lighter in weight and has a higher energy density than batteries such as lithium-ion, nickel metal hydride or nickel-cadmium batteries. These features are highly desirable for batteries for portable electronic devices such as cell phones and laptop-top computers, where a premium is paid for with a low weight.

A conventional lithium ion battery has an energy density of 700 wh/l using graphite for an anode and lithium cobalt oxide (LCO) for a cathode. However, recently, as fields requiring high energy density are expanding, the need to increase the energy density of lithium ion batteries is continuously being raised. For example, an increase in energy density is required to increase the driving distance of an electric vehicle to more than 500 km on a single charge.

In order to increase the energy density of lithium ion batteries, the use of lithium electrodes is increasing. However, lithium metal is highly reactive and difficult to handle in a process.

In order to solve this problem, various attempts have been made to manufacture an electrode using lithium metal.

For example, recently, a method of forming a lithium metal layer by depositing lithium metal on a substrate and then transferring the lithium metal layer onto a current collector such as Cu foil has been proposed, but it has been suggested that high-temperature deposited lithium and the substrate film may react. There is a problem.

Accordingly, a method for manufacturing a lithium electrode including a process of depositing lithium metal after forming a protective layer on a substrate for protecting lithium metal has been proposed, but a burden due to reduced process efficiency and increased cost due to the formation of a separate protective layer there is

In addition, Korea Patent Publication No. 2012-0036862 discloses a separator/anode assembly including a porous separator-anode layer (lithium metal)-anode current collector layer (copper layer), but due to non-uniform pores formed in the porous separator There is a problem with being vulnerable to heat.

Accordingly, there is a steady demand for technology development capable of solving the problem of lithium metal inevitably being exposed to high temperatures and being damaged in the conventional lithium electrode manufacturing process.

Korean Patent Publication No. 2012-0036862 "Battery using electrode direct coating on nanoporous separator" US Patent Publication No. 2009-0169984 "Composite separator films for lithium-ion batteries"

Accordingly, the inventors of the present invention have conducted various studies to stably manufacture a lithium electrode to solve the above problem. As a result, lithium metal is deposited on a porous substrate that can also be used as a separator, and then laminated with a current collector. By using a highly heat-resistant porous substrate in which pores of uniform size are formed with a high porosity, the highly heat-resistant porous substrate can protect lithium metal during the lithium electrode manufacturing process and is a separator-integrated type that can perform the functions of a separator and an electrode at the same time. The present invention was completed by confirming that a lithium electrode could be manufactured.

Accordingly, an object of the present invention is to provide a separator-integrated lithium electrode capable of simultaneously performing the functions of a separator and an electrode.

Another object of the present invention is to provide a method for manufacturing such a separator-integrated lithium electrode.

Another object of the present invention is to provide a lithium secondary battery including such a separator-integrated lithium electrode.

In order to achieve the above object, the present invention provides a lithium electrode including a highly heat-resistant porous substrate and a lithium metal layer formed on at least one surface of the porous substrate.

The diameter of pores included in the highly heat-resistant porous substrate may be 0.01 μm to 10 μm.

The porosity of the highly heat resistant porous substrate may be 0.1% to 80%.

The highly heat-resistant porous substrate is polyethylene terephthalate (PET), polypropylene (PP), polyester, polyacetal, polyamide, polycarbonate, polyimide, polyether ether ketone, polyetherimide (PEI), poly It may be formed of one or more highly heat-resistant polymers selected from the group consisting of amideimide, polyethersulfone (PES), polyphenylene oxide, polyphenylene sulfide, and polyethylene naphthalene.

The lithium metal layer may be formed on one surface of the current collector.

The present invention also includes the steps of (S1) forming a lithium metal layer on at least one surface of a highly heat-resistant porous substrate; and (S2) laminating a current collector to one surface of the lithium metal layer.

The lithium metal layer of the step (S1) may be formed by deposition.

The deposition is a chemical vapor deposition (CVD) method, a plasma-enhanced chemical vapor deposition (PECVD) method, a sputtering method, an E-beam evaporation method, thermal evaporation ) method, a laser molecular beam epitaxy (L-MBE) method, a pulsed laser deposition (PLD) method, and an atomic layer deposition (Atomic layer deposition) method.

Laminating in step (S2) may be performed by rolling.

The present invention also provides a lithium secondary battery including a lithium electrode.

The lithium secondary battery may include a lithium electrode as a negative electrode and may further include a separator interposed between the negative electrode and the positive electrode.

According to the lithium electrode of the present invention, the porous substrate, which is a separator formed integrally with the lithium electrode, has a uniform size and a high porosity, so that lithium ions can be uniformly distributed.

In addition, since the lithium electrode according to the present invention uses a porous substrate made of a material such as polyethylene terephthalate (PET) having high heat resistance, it is stable against high heat generated during the manufacturing process of the lithium electrode.

In addition, the lithium electrode according to the present invention is integrally formed with a porous substrate having high heat resistance, and growth of lithium dendrites can be prevented due to the pores of the porous substrate having high heat resistance.

In addition, the lithium electrode may be advantageous in terms of process efficiency and cost reduction compared to a battery in which a highly heat-resistant porous substrate serving as a separator is integrally formed, and the separator is formed separately from the lithium electrode and not integrally.

1 is a schematic diagram showing a cross section of a lithium electrode according to an embodiment of the present invention.
2 is a graph showing discharge capacity and coulombic efficiency measured by charging and discharging coin cells manufactured in Examples 1 to 3 and Comparative Example 1, respectively.

Hereinafter, the present invention will be described in detail with reference to the drawings.

The present invention relates to a lithium electrode in which a porous substrate serving as a separator is integrally formed, and in this specification, such a lithium electrode is referred to as a separator-integrated lithium electrode.

lithium electrode

1 is a schematic diagram of a lithium electrode according to an embodiment of the present invention.

Referring to FIG. 1 , the lithium electrode 100 according to the present invention may include a highly heat-resistant porous substrate 10 and a lithium metal layer 20 formed on one surface of the porous substrate 10, and On one side, the current collector 30 may be laminated.

In the present invention, the highly heat-resistant porous substrate serves as a separator when applied to a battery, and is characterized in that it is integrally formed with a lithium electrode, unlike in a general battery where the electrode and the separator are separated.

The highly heat-resistant porous substrate also serves as a substrate for the lithium metal layer in the lithium electrode manufacturing process, and exhibits stable characteristics even at high heat generated in the process of depositing lithium metal.

In addition, the highly heat-resistant porous substrate includes polyethylene terephthalate (PET), polypropylene (PP), polyester, polyacetal, polyamide, polycarbonate, polyimide, polyether ether ketone, polyetherimide (PEI), and polyamide. A porous substrate made of at least one high heat-resistant polymer selected from the group consisting of mead, polyethersulfone (PES), polyphenylene oxide, polyphenylene sulfide, and polyethylene naphthalene, and in particular, polyethylene terephthalate (PET) may be advantageous in terms of high heat resistance.

In addition, the highly heat-resistant porous substrate has a high porosity and a uniform size of the pores, so that lithium ions included in the pores can be uniformly distributed in the highly heat-resistant porous substrate.

The porosity of the highly heat-resistant porous substrate may be 0.1% to 80%, preferably 5% to 70%, and more preferably 10% to 60%, and if it is less than the above range, lithium ion conductivity may be lowered, If it exceeds the above range, there may be a problem in that durability is lowered.

In addition, the diameter of the highly heat resistant porous substrate may be 0.01 μm to 10 μm, preferably 0.1 μm to 8 μm, and more preferably 0.2 μm to 5 μm. If it is less than the above range, lithium ion conductivity may decrease, and if it exceeds the above range, durability may deteriorate.

In addition, the heat-resistant porous substrate may have a heat shrinkage rate of 10% or less at 150 °C. In this case, if the heat shrinkage rate is greater than 10%, when exposed to high heat in a process such as deposition during the manufacturing process of the lithium electrode, the highly heat-resistant porous substrate may shrink and the lithium metal may be exposed to outside air or moisture.

According to the present invention, since a lithium electrode can be manufactured by a process of forming the highly heat-resistant porous substrate on the substrate, depositing lithium metal, and then laminating with a current collector, the high heat resistance formed on one side of the lithium metal during deposition The heat-resistant porous substrate can protect lithium metal from high temperatures and outside air.

Accordingly, the highly heat-resistant porous substrate may include a conductive polymer suitable for protecting lithium metal. The conductive polymer is polyaniline, polypyrrole, polythiophene, polyazulene, polypyridine, polyindole, polycarbazole, polyazine ( Polyazine), Polyquinone, Polyselenophene, Polytellurophene, Polyethylenedioxythiophene (PEDT), Polyacetylene, Poly-p-phenylene ), polyphenylene vinylene (PPV), and polyphenylene sulfide (Polyphenylene sulfide: PPS). Preferably, the conductive polymer may be polyaniline.

The weight of the conductive polymer included in the highly heat resistant porous substrate may be 10 to 20% by weight, preferably 12 to 18% by weight, more preferably 14 to 16% by weight, based on the total weight of the heat resistant porous substrate. If it is less than the above range, lithium metal may not be effectively protected during the manufacturing process or battery performance may be deteriorated, and if it exceeds the above range, functionality as a separator may be deteriorated.

In the present invention, the lithium metal layer means a metal layer containing a lithium metal element. The material of the lithium metal layer may be a lithium alloy, a lithium metal, an oxide of a lithium alloy, or a lithium oxide. The lithium alloy includes at least one metal selected from the group consisting of lithium, aluminum (Al), tin (Sn), magnesium (Mg), indium (In), calcium (Ca), titanium (Ti) and vanadium (V), and It may mean an alloy of

The thickness of the lithium metal layer may be 10 μm to 200 μm, preferably 10 μm to 100 μm, and more preferably 10 μm to 80 μm. If it is less than the above range, life characteristics of the battery may deteriorate, and if it exceeds the above range, the thickness of the battery may increase.

In the present invention, the collector is made of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface treated with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. can The metal material for the current collector is not limited thereto as long as it is a metal having high conductivity and can easily transfer a lithium metal layer, but preferably, the current collector may be a copper current collector.

In addition, various forms such as a film, a sheet, a foil, a net, a porous material, a foam, and a nonwoven fabric may be used as the collector.

In addition, the current collector may be a porous current collector. When the current collector is a porous current collector including pores, a lithium metal layer may be included in the pores in the porous current collector, and at this time, except for a terminal connected to the porous current collector and extending to the outside, the porous current collector A protective layer may be provided on the entire surface. In addition, when pores are included in the porous current collector, sufficient battery capacity can be secured and an effect of inhibiting the formation of lithium dendrites can be obtained.

Manufacturing method of lithium electrode

The present invention also relates to a method for manufacturing a lithium electrode, comprising: (S1) forming a lithium metal layer on one surface of a highly heat-resistant porous substrate; and (S2) laminating a current collector to one surface of the lithium metal layer.

Step (S1)

In step (S1), a lithium metal layer may be formed by depositing lithium metal on one surface of the porous substrate having high heat resistance.

The deposition method includes a chemical vapor deposition (CVD) method, a plasma-enhanced chemical vapor deposition (PECVD) method, a sputtering method, an E-beam evaporation method, and a thermal evaporation method. evaporation) method, laser molecular beam epitaxy (L-MBE) method, pulsed laser deposition (PLD) method, and atomic layer deposition (Atomic layer deposition) method. In particular, when depositing lithium metal using a thermal evaporation method, it may be advantageous in terms of process efficiency.

As described above, the highly heat-resistant porous substrate also serves as a substrate for the lithium metal layer in the lithium electrode manufacturing process, and exhibits stable characteristics even at high heat generated in the process of depositing lithium metal.

In addition, the highly heat-resistant porous substrate includes polyethylene terephthalate (PET), polypropylene (PP), polyester, polyacetal, polyamide, polycarbonate, polyimide, polyether ether ketone, polyetherimide (PEI), and polyamide. A porous substrate made of at least one high heat-resistant polymer selected from the group consisting of mead, polyethersulfone (PES), polyphenylene oxide, polyphenylene sulfide, and polyethylene naphthalene, and in particular, polyethylene terephthalate (PET) may be advantageous in terms of high heat resistance.

In addition, the highly heat-resistant porous substrate has a high porosity and a uniform size of the pores, so that lithium ions included in the pores can be uniformly distributed in the highly heat-resistant porous substrate.

The porosity of the highly heat-resistant porous substrate may be 0.1% to 80%, preferably 10% to 70%, and more preferably 20% to 60%, and if it is less than the above range, lithium ion conductivity may be lowered, If it exceeds the above range, there may be a problem in that durability is lowered.

In addition, the diameter of the highly heat resistant porous substrate may be 0.01 μm to 10 μm, preferably 0.1 μm to 8 μm, and more preferably 0.2 μm to 5 μm. If it is less than the above range, lithium ion conductivity may decrease, and if it exceeds the above range, durability may deteriorate.

In addition, the heat-resistant porous substrate may have a heat shrinkage rate of 10% or less at 150 °C. In this case, if the heat shrinkage rate is greater than 10%, when exposed to high heat in a process such as deposition during the manufacturing process of the lithium electrode, the highly heat-resistant porous substrate may shrink and the lithium metal may be exposed to outside air or moisture.

In addition, the thickness of the deposited lithium metal layer may be 10 μm to 200 μm, preferably 10 μm to 100 μm, and more preferably 10 μm to 80 μm. If it is less than the above range, life characteristics of the battery may deteriorate, and if it exceeds the above range, the thickness of the battery may increase.

Step (S2)

In step (S2), a current collector may be laminated to one surface of the lithium metal layer.

The laminating may be performed by rolling, but is not limited thereto, and a method capable of laminating a lithium metal layer and a current collector may be widely used.

As described above, the types of current collectors that can be used include copper, stainless steel, aluminum, nickel, titanium, fired carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., aluminum- A cadmium alloy or the like may be used. The metal material for the current collector is not limited thereto as long as it is a metal having high conductivity and can easily transfer a lithium metal layer, but preferably, the current collector may be a copper current collector.

In addition, various forms such as a film, a sheet, a foil, a net, a porous material, a foam, and a nonwoven fabric may be used as the collector.

lithium secondary battery

The present invention also relates to a lithium secondary battery including a lithium electrode as described above, that is, a separator-integrated lithium electrode. At this time, the lithium electrode can be used as a negative electrode, and since the separator is integrally formed with the negative electrode, a separate separator is not required.

Alternatively, the lithium secondary battery may further include the negative electrode, the positive electrode, and a separator interposed therebetween, using the separator-integrated lithium electrode as a negative electrode.

The separator may be an insulating thin film having high ion permeability and mechanical strength, and may generally have a pore diameter of 0.01 μm to 10 μm and a thickness of 5 μm to 300 μm. As such a separator, a porous polymer film made of a polyolefin polymer such as ethylene homopolymer, propylene homopolymer, ethylene/butene copolymer, itelin/hexene copolymer, and ethylene/methacrylate copolymer is used alone. Or it may be used by laminating them, or a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high melting point glass fiber, polyethylene terephthalate fiber, etc. may be used, but is not limited thereto.

In addition, as a separate separator, a separator that separates or insulates the negative electrode and the positive electrode from each other and enables ion transport between the negative electrode and the positive electrode may be included. For example, it may be a non-conductive porous film or an insulating porous film. More specifically, polymeric non-woven fabrics such as non-woven fabrics made of polypropylene or non-woven fabrics made of polyphenylene sulfide; Alternatively, a porous film of an olefinic resin such as polyethylene or polypropylene can be exemplified, and it is also possible to use two or more of these in combination.

The separator may be made of a porous substrate, and the porous substrate may be any porous substrate commonly used in electrochemical devices, and for example, a polyolefin-based porous membrane or non-woven fabric may be used. It is not particularly limited.

Examples of the polyolefin-based porous membrane include polyethylene such as high-density polyethylene, linear low-density polyethylene, low-density polyethylene, and ultra-high molecular weight polyethylene, and polyolefin-based polymers such as polypropylene, polybutylene, and polypentene, each alone or a mixture thereof. one membrane.

In addition to the polyolefin-based nonwoven fabric, the nonwoven fabric includes, for example, polyethyleneterephthalate, polybutyleneterephthalate, polyester, polyacetal, polyamide, and polycarbonate. ), polyimide, polyetheretherketone, polyethersulfone, polyphenyleneoxide, polyphenylenesulfide, and polyethylenenaphthalene, respectively alone or A nonwoven fabric formed from a polymer obtained by mixing these is exemplified. The structure of the nonwoven fabric may be a spunbond nonwoven fabric or a melt blown nonwoven fabric composed of long fibers.

The thickness of the porous substrate is not particularly limited, but is 1 μm to 100 μm, or 5 μm to 50 μm. The size and porosity of the pores present in the porous substrate are also not particularly limited, but may be 0.001 μm to 50 μm and 10% to 95%, respectively.

By including a separate separator in this way, a shutdown function can be further improved.

Thus, the lithium secondary battery may include a negative electrode, a positive electrode, which is a separator-integrated lithium electrode as described above, and an electrolyte provided between the negative electrode and the positive electrode.

The shape of the lithium secondary battery is not limited, and may be, for example, a coin type, a flat plate type, a cylindrical shape, a cone type, a button type, a sheet type, or a laminated type. In addition, the lithium secondary battery may be manufactured as a flow battery by further including a tank for storing the positive and negative electrolytes and a pump for moving each electrolyte to the electrode cell.

In addition, the electrolyte may be an electrolyte solution in which the negative electrode and the positive electrode are impregnated.

The lithium secondary battery may further include a positive electrode electrolyte on the positive electrode side and a negative electrode electrolyte on the negative electrode side. The positive electrolyte solution and the negative electrolyte solution may each include a solvent and an electrolyte salt. The anode electrolyte and the cathode electrolyte may be the same as or different from each other.

The electrolyte solution may be an aqueous electrolyte solution or a non-aqueous electrolyte solution. The aqueous electrolyte solution may include water as a solvent, and the non-aqueous electrolyte solution may include a non-aqueous solvent as a solvent.

The non-aqueous solvent may be selected from those commonly used in the art, and is not particularly limited. For example, carbonate, ester, ether, ketone, organosulfur, and organophosphorous )-based, aprotic solvents, and combinations thereof.

The electrolytic salt refers to dissociation into cations and anions in water or a non-aqueous organic solvent, and is not particularly limited as long as it can transfer lithium ions in a lithium secondary battery, and one commonly used in the art may be selected.

The concentration of the electrolyte salt in the electrolyte may be 0.1 M or more and 3 M or less. In this case, the charge and discharge characteristics of the lithium secondary battery can be effectively expressed.

The electrolyte may be a solid electrolyte membrane or a polymer electrolyte membrane.

Materials of the solid electrolyte membrane and the polymer electrolyte membrane are not particularly limited, and those generally used in the art may be employed. For example, the solid electrolyte membrane may include a composite metal oxide, and the polymer electrolyte membrane may be a membrane having a conductive polymer inside a porous substrate.

In addition, the positive electrode means an electrode that accepts electrons and reduces lithium-containing ions when the battery is discharged in a lithium secondary battery. Conversely, when the battery is charged, it serves as a negative electrode (oxidation electrode), and the positive electrode active material is oxidized to release electrons and lose lithium-containing ions.

The cathode may include a cathode current collector and a cathode active material layer formed on the cathode current collector.

In the present specification, the material of the positive electrode active material of the positive electrode active material layer is not particularly limited as long as it is applied to a lithium secondary battery together with the negative electrode so that lithium-containing ions can be reduced during discharge and oxidized during charge. For example, it may be a composite material based on a transition metal oxide or sulfur (S), specifically LiCoO ₂ , LiNiO ₂ , LiFePO ₄ , LiMn ₂ O ₄ , LiNi _x Co _y MnzO ₂ (here, x+y+ z=1), at least one of Li ₂ FeSiO ₄ , Li ₂ FePO ₄ F, and Li ₂ MnO ₃ .

In addition, when the positive electrode is a composite material based on sulfur (S), the lithium secondary battery may be a lithium sulfur battery, and the composite material based on sulfur (S) is not particularly limited and is common in the art. It can be applied by selecting the anode material used as the

The present specification provides a battery module including the lithium secondary battery as a unit battery.

The battery module may be formed by stacking a bipolar plate provided between two or more lithium secondary batteries according to one embodiment of the present specification.

When the lithium secondary battery is a lithium air battery, the bipolar plate may be porous to supply air supplied from the outside to the positive electrode included in each lithium air battery. For example, it may include porous stainless steel or porous ceramic.

The battery module may be specifically used as a power source for an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

Example One

( 1) Separator Manufacture of all-in-one lithium electrode

A lithium metal layer was formed by thermally depositing lithium metal on a porous substrate, PET film (ipPore, It4ip Co.). At this time, thermal evaporation was performed using a deposition equipment (EWK-030, ULVAC Co.). At this time, the porosity of the PET film is 10%, and the diameter of the pores is 0.01 μm.

After that, a lithium electrode was manufactured by rolling and laminating the lithium metal layer and Cu foil as a current collector.

( 2) Lithium Secondary battery manufacturing

The above-prepared lithium electrode is used as a negative electrode, the positive electrode is LCO (LFX20N manufactured by LnF), and the electrolyte is a mixture of EC (Ethylene Carbonate), DEC (diethyl carbonate), and DMC (dimethyl carbonate) at a ratio of 1:2:1 And a lithium secondary battery in the form of a coin cell was prepared with a composition in which 1 mole of LiPF ₆ and 2% by weight of VC (Vinylene Carbonate) were added.

Example 2

In the same manner as in Example 1, a lithium electrode and a lithium secondary battery were prepared using a PET film (ipPore, It4ip), which is a porous substrate having a pore diameter of 0.1 μm and a porosity of 10%.

Example 3

In the same manner as in Example 1, a lithium electrode and a lithium secondary battery were prepared using a PET film (ipPore, It4ip), which is a porous substrate having a pore diameter of 0.2 μm and a porosity of 10%.

comparative example One

A lithium electrode and a lithium secondary battery were prepared in the same manner as in Example 1, except that a PE film (polyethylene film, SK innovation, LC2001 Grade) was used instead of the PET film.

Experimental Example 1: Discharge capacity of lithium electrode and coulombic efficiency measurement

The coin cells prepared in Examples 1 to 3 and Comparative Example 1 were cycled after charging and discharging C-rates were set to 0.2C and 0.5C, respectively, in a charger/discharger.

2 is a graph showing discharge capacity and coulombic efficiency measured by charging and discharging the coin cells manufactured in Examples 1 to 3 and Comparative Example 1, respectively.

Referring to FIG. 2, the coin cell of Example 1 was charged and discharged for nearly 100 cycles, and the coin cell of Examples 2 and 3 was charged and discharged for more than 150 cycles, whereas the coin cell of Comparative Example 1 was charged and discharged for 25 cycles. You can see that the cycle fading started before.

In addition, it can be seen that Example 3 has the best cycle life among Examples and Comparative Examples.

Although the present invention has been described above with limited examples and drawings, the present invention is not limited thereto, and is described below and the technical spirit of the present invention by those skilled in the art to which the present invention belongs. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be made.

100: lithium electrode
10: porous substrate
20: lithium metal layer
30: entire collector

Claims (11)

A lithium secondary battery including a separator-integrated lithium negative electrode, a positive electrode, and an electrolyte,
The separator-integrated lithium negative electrode includes a highly heat-resistant porous substrate and a lithium metal layer formed on at least one surface of the porous substrate,
The diameter of the pores included in the highly heat-resistant porous substrate is 0.01 μm to 0.2 μm,
The porosity of the highly heat-resistant porous substrate is 5% to 10%,
The highly heat-resistant porous substrate is polyethylene terephthalate (PET), a lithium secondary battery. delete delete delete According to claim 1,
The lithium metal layer is formed on one surface of the current collector, a lithium secondary battery.

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