Negative electrode for lithium secondary battery and lithium secondary battery comprising same

Abstract

The present disclosure provides a negative electrode for a lithium secondary battery and a lithium secondary battery comprising same. The negative electrode for a lithium secondary battery according to the present disclosure comprises: a negative electrode current collector; and an electrodeposition induction layer disposed on the negative electrode current collector and including metal particles and a conductive polymer, wherein the conductive polymer may include poly(3,4-ethylenedioxythiophene)-tetramethacrylate (PEDOT-TMA).

Description

Negative electrode for a lithium secondary battery, and a lithium secondary battery including the same

[0001] The present disclosure relates to a negative electrode for a lithium secondary battery and a lithium secondary battery comprising the same.

[0002]

[0003] Recently, accompanied by the rapid proliferation of battery-powered electronic devices such as mobile phones, laptop computers, and electric vehicles, the demand for high-energy-density, high-capacity rechargeable batteries is rapidly increasing. Accordingly, research and development to improve the performance of lithium-ion batteries is actively underway.

[0004] A lithium secondary battery is a battery comprising a positive electrode and a negative electrode containing an active material capable of lithium ion intercalation and deintercalation, and an electrolyte, and produces electrical energy through oxidation and reduction reactions when lithium ions are intercalated / deintercalated from the positive electrode and the negative electrode.

[0005] To date, various efforts have been made to reduce the size of the anode to increase the energy density of lithium-ion batteries. While thick lithium metal was used as the anode active material layer in lithium-ion batteries, carbon-based anode active materials such as graphite are now primarily used due to safety concerns, and new anode active materials such as silicon-carbon composites and thin lithium metal films are being developed. Recently, anode-free lithium-ion batteries, which do not have an anode active material layer, are also being developed.

[0006] Lithium secondary batteries that use lithium metal as the negative electrode active material layer or do not have a negative electrode active material layer have room for improvement as their energy density and long life characteristics do not reach satisfactory levels due to the formation and growth of lithium dendrites on the negative electrode.

[0007] Lithium metal batteries without a negative electrode active material layer may experience degradation in lifespan characteristics due to the continuous consumption of lithium during charging and discharging and the progression of irreversible reactions, as there is no source of extra lithium. Therefore, in order to drastically improve lifespan characteristics while maintaining the structure of a lithium metal battery without a negative electrode active material layer, a means to supply additional lithium within the cell is required.

[0008] The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art.

[0009]

[0010] The problem that the present invention aims to solve is to provide a negative electrode for a lithium secondary battery and a lithium secondary battery including the same to solve the above-mentioned problems.

[0011] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems can be clearly understood by those skilled in the art from the description of the invention below.

[0012]

[0013] According to one embodiment of the present disclosure for solving the above technical problem, a negative electrode for a lithium secondary battery comprises a negative electrode current collector and an electrodeposition inducing layer disposed on the negative electrode current collector and comprising metal particles and a conductive polymer, wherein the conductive polymer may comprise PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate).

[0014] According to one embodiment of the present disclosure for solving the above technical problem, a lithium secondary battery comprises a positive electrode, a negative electrode for a lithium secondary battery, and an electrolyte disposed between the positive electrode and the negative electrode for a lithium secondary battery, and the negative electrode for a lithium secondary battery comprises a negative electrode current collector and an electrodeposition inducing layer disposed on the negative electrode current collector and comprising metal particles and a conductive polymer, and the conductive polymer may comprise PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate).

[0015] According to one embodiment of the present disclosure for solving the above technical problem, a lithium secondary battery comprises a positive electrode including a positive current collector and a positive composite portion disposed on the positive current collector, a negative electrode including a negative current collector and an electrodeposition inducing layer disposed on the negative current collector, and an electrolyte disposed between the positive electrode and the negative electrode, wherein the positive composite portion comprises a positive active material and a sacrificial positive active material, and the electrodeposition inducing layer may comprise a conductive polymer having PEDOT (Poly(3,4-ethylenedioxythiophene)).

[0016]

[0017] A negative electrode for a lithium secondary battery or a lithium secondary battery according to some embodiments of the present disclosure can induce uniform electrodeposition of lithium during the charging process by forming an electrodeposition-inducing layer comprising a conductive polymer on a negative electrode current collector, so that the electrodeposition-inducing layer performs the role of a lithium electrodeposition layer.

[0018] A negative electrode for a lithium secondary battery or a lithium secondary battery according to some embodiments of the present disclosure can reduce the nucleation overpotential during lithium electrodeposition by forming metal particles in a conductive polymer included in an electrodeposition inducing layer.

[0019] A lithium secondary battery according to some embodiments of the present disclosure includes a sacrificial cathode that forms a lithium metal layer on a negative electrode substrate during the formation step, thereby compensating for lithium consumption caused by the generation of Solid Electrolyte Interphase (SEI) or other side reactions during charging and discharging, which can significantly improve the lifespan characteristics of the secondary battery.

[0020] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below.

[0021]

[0022] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0023] FIG. 1 is a drawing showing a stacked structure of a lithium secondary battery according to one embodiment of the present disclosure.

[0024] Figure 2 is a diagram showing the stacked structure of the lithium secondary battery of Figure 1 after charging.

[0025] FIG. 3 is a diagram showing a stacked structure of a negative electrode for a lithium secondary battery according to one embodiment of the present disclosure.

[0026] Figure 4 is an SEM image of the surface of an electrodeposition-inducing layer containing silver (Ag) particles, which are an example of metal particles, and a conductive polymer.

[0027] FIGS. 5 to 8 are drawings illustrating a lithium secondary battery according to one embodiment of the present disclosure.

[0028] FIG. 9 is a flowchart illustrating a method for manufacturing a negative electrode for a lithium secondary battery according to one embodiment of the present disclosure.

[0029] FIG. 10 is a flowchart illustrating a method for manufacturing a lithium secondary battery according to one embodiment of the present disclosure.

[0030] FIG. 11 shows 1.0 mA / cm² using the negative electrode for a lithium secondary battery of the example and comparative example according to the evaluation example. 2 This is the voltage profile when Li is electrodeposited at a current density.

[0031] FIGS. 12a to 12c are SEM images of the surface of the negative electrode on which lithium is electrodeposited in the lithium secondary batteries of the example and comparative example according to the evaluation example.

[0032] FIG. 13 shows 1.0 mA / cm² using the negative electrode of the lithium secondary battery of the example and comparative example according to the evaluation example. 2 This is the voltage profile when discharged at a current density.

[0033] FIG. 14 shows 1.0 mA / cm² using the negative electrode of the lithium secondary battery of the example and comparative example according to the evaluation example. 2 This is the voltage profile when Li is electrodeposited at a current density.

[0034]

[0035] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention, and the present invention is defined only by the scope of the claims set forth below.

[0036] Unless otherwise specifically stated in this specification, when a part such as a layer, film, region, plate, etc. is described as being "on" another part, this includes not only cases where it is "immediately on" another part, but also cases where there is another part in between.

[0037] Unless otherwise specified in this specification, a singular form may also include a plural form. Additionally, unless otherwise specified, "A or B" may mean "including A, including B, or including A and B."

[0038] In this specification, "combination of these" may mean a mixture of components, a laminate, a composite, a copolymer, an alloy, a blend, and a reaction product, etc.

[0039] Methods and materials similar or equivalent to those described herein may be used in the practice or testing of the present invention, but suitable methods and materials are described herein. The singular expression includes the plural expression unless the context clearly indicates otherwise.

[0040] In this specification, terms such as “comprising” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, components, materials, or combinations thereof described in the specification, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, parts, components, materials, or combinations thereof.

[0041] In this specification, the term “and / or” means any combination of one or more items described in relation and all combinations thereof. In this specification, the term “or” means “and / or”.

[0042] In this specification, when a part such as a layer, film, region, plate, etc. is described as being "on" another part, this includes not only cases where it is directly above the other part, but also cases where there is another part in between.

[0043] In this specification, terms such as "first," "second," etc., may be used to describe various components, but the components should not be limited by these terms. The terms are used solely for the purpose of distinguishing one component from another.

[0044] In this specification, “metal” includes both metals and metalloids such as silicon and germanium in an elemental or ionic state. In this specification, “alloy” means a mixture of two or more metals.

[0045] In this specification, "anode active material" refers to an anode material capable of undergoing lithiation and delithiation. In this specification, "anode active material" refers to an anode material capable of undergoing lithiation and delithiation.

[0046] In this specification, "lithiation" and "to lithiate" refer to the process of adding lithium to a specific substance or compound. In this specification, "delithiation" and "to delithiate" refer to the process of removing lithium from a specific substance or compound.

[0047] In this specification, "charge" and "to charge" refer to the process of providing electrochemical energy to a battery. In this specification, "discharge" and "to discharge" refer to the process of removing electrochemical energy from a battery.

[0048] In this specification, "anode" and "cathode" refer to electrodes where electrochemical reduction and lithiation occur during the discharge process. In this specification, "negative electrode" and "anode" refer to electrodes where electrochemical oxidation and delithiation occur during the discharge process.

[0049] Exemplary embodiments will be described in more detail below.

[0050]

[0051] A negative electrode for a lithium secondary battery according to one embodiment of the present disclosure comprises a negative electrode current collector and an electrodeposition inducing layer disposed on the negative electrode current collector and comprising metal particles and a conductive polymer, wherein the conductive polymer may comprise PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate).

[0052] In one embodiment of the present disclosure, the metal particles may include a lithium-affinity metal.

[0053] In one embodiment of the present disclosure, the lithium-affinity metal may include silver (Ag), magnesium (Mg), zinc (Zn), aluminum (Al), tin (Sn), or a combination thereof.

[0054] In one embodiment of the present disclosure, the conductive polymer comprises an anionic dopant, and the anionic dopant may comprise perchlorate, sulfate, p-toluenesulfonate, polystyrene sulfonate, sodium dodecyl benzene sulfonate, or a combination thereof.

[0055] In one embodiment of the present disclosure, the thickness of the electrodeposition-inducing layer may be 0.1 μm or more and 10 μm or less.

[0056] A method for manufacturing a negative electrode for a lithium secondary battery according to one embodiment of the present disclosure comprises the steps of preparing a negative electrode current collector, placing an electrodeposition-inducing layer comprising a conductive polymer on the negative electrode current collector, and supporting the negative electrode current collector on which the electrodeposition-inducing layer is placed in an aqueous solution containing metal ions, wherein the conductive polymer may include PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate).

[0057] In one embodiment of the present disclosure, the step of placing an electrodeposition-inducing layer may include the step of spray-coating a solution containing a conductive polymer onto a negative current collector.

[0058] In one embodiment of the present disclosure, the content of the conductive polymer may be 0.1% to 15% by weight based on the total weight of the solution.

[0059] A lithium secondary battery according to one embodiment of the present disclosure comprises a positive electrode, a negative electrode for a lithium secondary battery, and an electrolyte disposed between the positive electrode and the negative electrode for a lithium secondary battery, wherein the negative electrode for a lithium secondary battery comprises a negative electrode current collector and an electrodeposition inducing layer disposed on the negative electrode current collector and comprising metal particles and a conductive polymer, and the conductive polymer may comprise PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate).

[0060] In one embodiment of the present disclosure, the negative active material layer on the negative current collector may be free before charging is performed.

[0061] In one embodiment of the present disclosure, the electrolyte comprises a carbonate-based organic solvent and a lithium salt, and the carbonate-based organic solvent may comprise fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methyl ethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), or a combination thereof.

[0062] In one embodiment of the present disclosure, the electrolyte may further include a crosslinking agent for forming a polymer matrix.

[0063] In one embodiment of the present disclosure, at least a portion of the conductive polymer may be cross-linked with at least a portion of the cross-linking agent.

[0064]

[0065] A lithium secondary battery according to one embodiment of the present disclosure comprises a positive electrode including a positive current collector and a positive composite portion disposed on the positive current collector, a negative electrode including a negative current collector and an electrodeposition inducing layer disposed on the negative current collector, and an electrolyte disposed between the positive electrode and the negative electrode, wherein the positive composite portion comprises a positive active material and a sacrificial positive active material, and the electrodeposition inducing layer may comprise a conductive polymer having PEDOT (Poly(3,4-ethylenedioxythiophene)).

[0066] In one embodiment of the present disclosure, the conductive polymer may comprise PEDOT (Poly(3,4-ethylenedioxythiophene)), PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate), PEDOT-PSS (Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate), PEDOT-PEG (poly(3,4-ethylenedioxythiophene)-co-poly(ethylene glycol)), or a combination thereof.

[0067] In one embodiment of the present disclosure, the conductive polymer comprises an anionic dopant, and the anionic dopant may comprise perchlorate, sulfate, p-toluenesulfonate, polystyrene sulfonate, sodium dodecyl benzene sulfonate, or a combination thereof.

[0068] In one embodiment of the present disclosure, the electrodeposition-inducing layer may further include metal particles.

[0069] In one embodiment of the present disclosure, the thickness of the electrodeposition-inducing layer may be 0.1 μm or more and 10 μm or less.

[0070] In one embodiment of the present disclosure, the sacrificial cathode active material may include Li5FeO4, Li2MoO3, Li6CoO4, Li2O, Li3N, Li3P, or a combination thereof.

[0071] In one embodiment of the present disclosure, the capacity ratio between the positive active material and the sacrificial positive active material may correspond to 1:1 to 9:1.

[0072] In one embodiment of the present disclosure, the positive electrode active material may comprise LiMO2 (M is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof), LiFePO4, LiM2O4 (M is Ti, V, Mn, or a combination thereof), or a combination thereof.

[0073] In one embodiment of the present disclosure, the negative active material layer on the negative current collector may be free before charging is performed.

[0074] In one embodiment of the present disclosure, the electrolyte comprises a carbonate-based organic solvent and a lithium salt, and the carbonate-based organic solvent may comprise fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methyl ethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), or a combination thereof.

[0075] In one embodiment of the present disclosure, the electrolyte may further include a crosslinking agent for forming a polymer matrix.

[0076] In one embodiment of the present disclosure, the lithium salt may comprise lithium hexafluorophosphate (LiPF6), lithium difluoro(oxalato)borate (LiDFOB), lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), or a combination thereof.

[0077] A method for manufacturing a lithium secondary battery according to one embodiment of the present disclosure comprises the steps of preparing a negative electrode, preparing a positive electrode, and placing an electrolyte between the positive electrode and the negative electrode. The step of preparing the negative electrode may include placing an electrodeposition-inducing layer comprising a conductive polymer having PEDOT (Poly(3,4-ethylenedioxythiophene)) on a negative electrode current collector, and the step of preparing the positive electrode may include placing a positive electrode composite portion comprising a positive electrode active material and a sacrificial positive electrode active material on a positive electrode current collector.

[0078] In one embodiment of the present disclosure, the step of disposing of an electrodeposition-inducing layer may include the step of spray-coating a solution containing the conductive polymer onto a negative current collector.

[0079] In one embodiment of the present disclosure, the content of the conductive polymer may be 0.1% to 15% by weight based on the total weight of the solution.

[0080] In one embodiment of the present disclosure, the step of preparing a cathode may further include the step of immersing a cathode current collector having an electrodeposition-inducing layer disposed thereon in an aqueous solution containing metal ions.

[0081]

[0082] lithium secondary battery

[0083] FIG. 1 is a drawing showing a stacked structure of a lithium secondary battery according to one embodiment of the present disclosure. FIG. 2 is a drawing showing a stacked structure of the lithium secondary battery of FIG. 1 after charging.

[0084] FIG. 1 is a drawing showing a stacked structure of a lithium secondary battery (100) in which a negative active material layer is absent on a negative current collector (120) before charging, and FIG. 2 may correspond to a drawing showing the appearance of lithium metal being deposited on a negative electrode (110) as the lithium secondary battery (100) of FIG. 1 is charged. The thickness of each layer shown in FIG. 1 and FIG. 2 is shown as an arbitrary size and is not necessarily limited thereto.

[0085] Referring to FIGS. 1 and 2, a lithium secondary battery (100) according to one embodiment of the present disclosure may include a positive electrode (140), a negative electrode (110), and an electrolyte (170) disposed between the positive electrode (140) and the negative electrode (110). In one embodiment, the negative electrode (110) may include a negative electrode current collector (120) and an electrodeposition inducing layer (130) disposed on the negative electrode current collector (120).

[0086] In one embodiment, the lithium secondary battery (100) may not have a negative active material layer on the negative current collector (120). In one embodiment, the lithium secondary battery (100) may have a lithium metal layer (180) formed on the negative electrode (110) after charging. The lithium metal layer (180) may be disposed between the electrodeposition inducing layer (130) and the electrolyte (170). For example, the lithium metal layer (180) may be a lithium electrodeposition layer.

[0087]

[0088] Negative electrode for lithium secondary batteries

[0089] FIG. 3 is a diagram showing a stacked structure of a negative electrode for a lithium secondary battery according to one embodiment of the present disclosure. The thickness of each layer shown in FIG. 3 is shown as an arbitrary size and is not necessarily limited thereto.

[0090] Referring to FIG. 3, a negative electrode (110) for a lithium secondary battery according to one embodiment of the present disclosure may include a negative electrode current collector (120) and an electrodeposition inducing layer (130) disposed on the negative electrode current collector (120).

[0091]

[0092] Negative electrode for lithium secondary battery: Electrodeposition inducing layer

[0093] The electrodeposition-inducing layer (130) disposed on the negative current collector (120) may include at least one of metal particles and a conductive polymer.

[0094]

[0095] (1) Electrodeposition-inducing layer containing metal particles and conductive polymer

[0096] In one embodiment, the electrodeposition inducing layer (130) disposed on the negative current collector (120) may include metal particles and a conductive polymer. The conductive polymer may include PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate). For example, the metal particles may be disposed on the surface of the electrodeposition inducing layer or inserted into it. Alternatively, the metal particles may be disposed on the surface and inside the electrodeposition inducing layer. The metal particles may be uniformly disposed. Due to the conductive polymer, the electrodeposition inducing layer (130) may function as a lithium electrodeposition layer.

[0097] In one embodiment, the electrodeposition-inducing layer may include an anionic dopant. The anionic dopant may include, for example, perchlorate, sulfonate, p-toluenesulfonate, polystyrene sulfonate, sodium dodecyl benzene sulfonate, or a combination thereof.

[0098] In one embodiment, the metal particles may comprise a lithium-affinity metal. The lithium-affinity metal may comprise, for example, silver (Ag), magnesium (Mg), zinc (Zn), aluminum (Al), tin (Sn), or a combination thereof. The metal particles may be formed on the surface of the conductive polymer by immersing a negative current collector (120), on which an electrodeposition-inducing layer (130) comprising the conductive polymer is disposed, in an aqueous solution containing metal ions. The aqueous solution containing silver ions may comprise, for example, an aqueous solution of silver nitrate (AgNO3), an aqueous solution of silver chloride (AgCl), an aqueous solution of silver nitrite (AgNO2), an aqueous solution of silver sulfate (Ag2SO4), or a combination thereof. The aqueous solution containing magnesium ions may comprise, for example, an aqueous solution of magnesium chloride (MgCl2), an aqueous solution of magnesium sulfate (MgSO4), an aqueous solution of magnesium nitrate (Mg(NO3)2), an aqueous solution of magnesium carbonate (MgCO3), or a combination thereof. Aqueous solutions containing zinc ions may include, for example, an aqueous solution of zinc chloride (ZnCl2), an aqueous solution of zinc sulfate (ZnSO4), an aqueous solution of zinc nitrate (Zn(NO3)2), an aqueous solution of zinc acetate (Zn(CH3COO)2), an aqueous solution of zinc carbonate (ZnCO3), or a combination thereof. Aqueous solutions containing aluminum ions may include, for example, an aqueous solution of aluminum chloride (AlCl3), an aqueous solution of aluminum sulfate (Al2(SO4)3), an aqueous solution of aluminum nitrate (Al(NO3)3), an aqueous solution of aluminum acetate (Al(CH3COO)3), or a combination thereof. Aqueous solutions containing tin ions may include an aqueous solution of tin octoate (Sn(Oct)2), a tin laurate (Sn(C 11 H 23 COO)2) aqueous solution, tin stearate (Sn(C 17 H 35 Aqueous solution of COO)2), aqueous solution of tin acetate (Sn(CH3COO)2), aqueous solution of tin oleate (Sn(C 17 H 33 It may include an aqueous solution of COO)2), an aqueous solution of tin butyrate (Sn(C3H7COO)2), or a combination thereof.

[0099] The concentration of the aqueous solution containing metal ions may be, for example, 0.1 mM to 20 mM. The time for immersing the negative current collector (120) on which the electrodeposition inducing layer (130) is disposed in the aqueous solution containing metal ions may be, for example, 1 hour or less. Metal particles may be formed on the surface of the conductive polymer by reducing the metal ions contained in the aqueous solution by the anionic dopant contained in the conductive polymer. If the immersion concentration is too low (e.g., 0.1 mM or less), metal ion coordination does not occur well, and metal particles (e.g., silver particles) that are reduced on the surface may not be sufficiently generated. If the immersion concentration is too high (e.g., 20 mM or more) or the immersion time is too long (e.g., 1 hour or more), the particles may not be evenly distributed on the surface, and a corrosion reaction in which copper is oxidized and silver is reduced may occur.

[0100] For example, the metal particles may be metal nanoparticles. The metal particles may act as nucleation seeds during the process of lithium being electrodeposited on the negative electrode (110) of a lithium secondary battery when charging a lithium secondary battery including the negative electrode (110) of a lithium secondary battery, thereby reducing the nucleation over-potential.

[0101] In one embodiment, the thickness of the electrodeposition inducing layer (130) may be 0.1 μm or more and 10 μm or less, 0.1 μm or more and 5 μm or less, or 0.5 μm or more and 2 μm or less.

[0102]

[0103] (2) Electrodeposition inducing layer containing a conductive polymer having PEDOT

[0104] In one embodiment, the electrodeposition inducing layer (130) disposed on the negative electrode current collector (120) may include a conductive polymer having PEDOT (Poly(3,4-ethylenedioxythiophene)). Due to the conductive polymer, the electrodeposition inducing layer (130) can perform the role of a lithium electrodeposition layer. For example, the conductive polymer may include PEDOT (Poly(3,4-ethylenedioxythiophene)), PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate), PEDOT-PSS (Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate), PEDOT-PEG (poly(3,4-ethylenedioxythiophene)-co-poly(ethylene glycol)), or a combination thereof.

[0105] In one embodiment, the conductive polymer may include an anionic dopant. For example, the anionic dopant may include perchlorate, sulfate, p-toluenesulfonate, polystyrene sulfonate, sodium dodecyl benzene sulfonate, or a combination thereof.

[0106] In one embodiment, the electrodeposition inducing layer (130) may further include metal particles. For example, the electrodeposition inducing layer (130) may further include silver (Ag) particles. Silver particles may be formed by immersing the cathode current collector (120) on which the electrodeposition inducing layer (130) is disposed in an aqueous solution containing silver ions. The aqueous solution containing silver ions may include, for example, an aqueous solution of silver nitrate (AgNO3), an aqueous solution of silver chloride (AgCl), an aqueous solution of silver nitrite (AgNO2), an aqueous solution of silver sulfate (Ag2SO4), or a combination thereof. The concentration of the aqueous solution containing silver ions may be, for example, 0.1 mM to 30 mM. The time for immersing the cathode current collector (120) on which the electrodeposition inducing layer (130) is disposed in the aqueous solution containing silver ions may be, for example, 1 hour or less. Silver particles can be formed on the surface of a conductive polymer by reducing silver ions contained in an aqueous solution by an anionic dopant contained in the conductive polymer. The silver particles can act as nucleation seeds during the process of lithium being electrodeposited on the negative electrode (110) when charging the secondary battery (100), thereby reducing the nucleation over-potential.

[0107] In one embodiment, the metal particles may comprise a lithium-affinity metal. The lithium-affinity metal may comprise, for example, silver (Ag), magnesium (Mg), zinc (Zn), aluminum (Al), tin (Sn), or a combination thereof. The metal particles may be formed on the surface of a conductive polymer by immersing a negative current collector (120), on which an electrodeposition-inducing layer (130) comprising a conductive polymer is disposed, in an aqueous solution containing metal ions. The aqueous solution containing magnesium ions may comprise, for example, an aqueous solution of magnesium chloride (MgCl2), an aqueous solution of magnesium sulfate (MgSO4), an aqueous solution of magnesium nitrate (Mg(NO3)2), an aqueous solution of magnesium carbonate (MgCO3), or a combination thereof. Aqueous solutions containing zinc ions may include, for example, an aqueous solution of zinc chloride (ZnCl2), an aqueous solution of zinc sulfate (ZnSO4), an aqueous solution of zinc nitrate (Zn(NO3)2), an aqueous solution of zinc acetate (Zn(CH3COO)2), an aqueous solution of zinc carbonate (ZnCO3), or a combination thereof. Aqueous solutions containing aluminum ions may include, for example, an aqueous solution of aluminum chloride (AlCl3), an aqueous solution of aluminum sulfate (Al2(SO4)3), an aqueous solution of aluminum nitrate (Al(NO3)3), an aqueous solution of aluminum acetate (Al(CH3COO)3), or a combination thereof. Aqueous solutions containing tin ions may include an aqueous solution of tin octoate (Sn(Oct)2), a tin laurate (Sn(C 11 H 23 COO)2) aqueous solution, tin stearate (Sn(C 17 H 35 Aqueous solution of COO)2), aqueous solution of tin acetate (Sn(CH3COO)2), aqueous solution of tin oleate (Sn(C 17 H 33 It may include an aqueous solution of COO)2), an aqueous solution of tin butyrate (Sn(C3H7COO)2), or a combination thereof.

[0108] In one embodiment, the thickness of the electrodeposition inducing layer (130) may be 0.1 μm or more and 10 μm or less, 0.1 μm or more and 5 μm or less, or 0.5 μm or more and 2 μm or less.

[0109]

[0110] In one embodiment, the positive electrode (140) may include a positive electrode current collector (150) and a positive electrode composite portion (160) disposed on the positive electrode current collector (150). The positive electrode current collector (150) may include, for example, indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof.

[0111] In one embodiment, the anode composite section (160) may include an anode active material and a sacrificial anode active material. For example, the anode composite section (160) may include an anode active material, a sacrificial anode active material, a conductive material, and a binder. The anode active material may include, for example, LiMO2 (M is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof), LiFePO4, LiM2O4 (M is Ti, V, Mn, or a combination thereof), or a combination thereof. The sacrificial anode active material may include, for example, Li5FeO4, Li2MoO3, Li6CoO4, Li2O, Li3N, Li3P, or a combination thereof. In the anode composite section (160), the capacity ratio between the anode active material and the sacrificial anode active material may be 1:1 to 9:1.

[0112] In one embodiment, the sacrificial positive active material included in the positive composite part (160) can form a lithium metal layer (180) on the negative electrode (110) during the formation step in the manufacturing process of the lithium secondary battery (100). Through this process, the lifespan characteristics of the secondary battery can be significantly improved by compensating for irreversible lithium consumption caused by SEI generation or other side reactions during the charging and discharging of the lithium secondary battery (100); however, when using a sacrificial positive active material, lithium may be electrodeposited unevenly on the negative electrode current collector (120) compared to when a sacrificial positive active material is not used. In one embodiment, by placing an electrodeposition inducing layer (130) on the negative electrode current collector (120), uneven electrodeposition of lithium can be prevented in the lithium secondary battery (100) including the positive composite part (160) having the sacrificial positive active material.

[0113] In one embodiment, the electrolyte (170) disposed between the anode (140) and the cathode (110) may include a lithium salt and an organic solvent. The lithium salt may include, for example, lithium hexafluorophosphate (LiPF6), lithium difluoro(oxalato)borate (LiDFOB), lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), or a combination thereof.

[0114] Any organic solvent used as an organic solvent in the relevant technical field is acceptable. For example, organic solvents may include carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvents, aprotic solvents, or combinations thereof.

[0115] In one embodiment, the electrolyte (170) may further include a crosslinking agent to form a polymer matrix. The electrolyte (170) further including the crosslinking agent has high electrochemical safety and can maintain a constant thickness of the battery. The crosslinking agent may include, for example, PETTA (pentaerythritol tetraacrylate), DPHA (dipentaerythritol hexacrylate), TMPTMA (trimethylolpropane trimethacrylate), or a combination thereof. If the conductive polymer included in the electrodeposition inducing layer (130) includes PEDOT-TMA, at least a portion of the conductive polymer may crosslink with at least a portion of the crosslinking agent. Due to the crosslinking between the conductive polymer and the crosslinking agent, the contact between the electrolyte (170) and the negative electrode (110) is excellent, and uniform lithium electrodeposition may be possible.

[0116] Figure 4 is an SEM image of the surface of an electrodeposition-inducing layer containing silver (Ag) particles, which are an example of metal particles, and a conductive polymer. In Figure 4, the areas that appear bright in contrast to other parts may correspond to the metal particles.

[0117] Referring to FIG. 4, after a negative current collector (120) having an electrodeposition inducing layer (130) containing a conductive polymer is immersed in an aqueous solution containing metal ions, metal particles, such as silver particles, can be evenly dispersed on the surface of the conductive polymer. The metal particles may be uniformly disposed on the surface and / or inside the electrodeposition inducing layer, or inserted therein. Because the metal particles are evenly dispersed on the surface of the conductive polymer, the metal particles can uniformly perform the role of reducing the nucleation over-potential during lithium electrodeposition throughout the electrodeposition inducing layer (130). In one embodiment, the particle size of the metal particles may be greater than 0 nm and less than 100 nm.

[0118] FIGS. 5 to 8 illustrate a lithium secondary battery according to an embodiment of the present disclosure, wherein FIG. 5 is cylindrical, FIG. 6 is prismatic, and FIGS. 7 and 8 are pouch-type batteries. Referring to FIGS. 5 to 8, the lithium secondary battery (1) includes a battery structure (7, electrode assembly) having a separator (4, separator) interposed between a positive electrode (3) and a negative electrode (2), and a case (5) in which the battery structure (7) is housed. The positive electrode (3), the negative electrode (2), and the separator (4) may be impregnated with an electrolyte (not shown). The lithium secondary battery (1) may include an assembly (6, sealing member) that seals the case (5) as in FIG. 5. Additionally, in FIG. 6, the lithium secondary battery (1) may include a positive lead tab (3') and a positive terminal (3"), a negative lead tab (2') and a negative terminal (2"). As shown in FIGS. 7 and 8, the lithium secondary battery (1) may include electrode tabs (70), namely a positive electrode tab (71) and a negative electrode tab (72), which serve as electrical passages for inducing current formed in the battery structure (7) to the outside.

[0119] Referring to FIG. 5, a lithium secondary battery (1) according to one embodiment includes the anode (3), the cathode (2), and the separator (4) described above. The anode (3), the cathode (2), and the separator (4) are wound or folded to form a battery structure (7). The formed battery structure (7) is housed in a case (5). An electrolyte is injected into the case (5) and sealed with a cap assembly (6) to complete the lithium secondary battery (1). The case (5) is cylindrical but is not necessarily limited to this shape and may be, for example, prismatic, thin film, etc.

[0120] Referring to FIG. 6, a lithium secondary battery (1) according to one embodiment includes a positive electrode (3), the aforementioned negative electrode (2), and a separator (4). The positive electrode (3), the negative electrode (2), and the separator (4) are wound, folded, or stacked to form a battery structure (7). The formed battery structure (7) is housed in a case (5). An electrolyte is injected into the case (5), cross-linked, and sealed to complete the lithium secondary battery (1). The case (5) is prismatic, but is not necessarily limited to this shape and may be, for example, cylindrical, thin film, etc. A positive lead tab (3') and a positive terminal (3") are electrically connected to the positive electrode (3). A negative lead tab (2') and a negative terminal (2") are electrically connected to the negative electrode (2).

[0121] Referring to FIG. 7, a lithium secondary battery (1) according to one embodiment includes a positive electrode (3), the aforementioned negative electrode (2), and a separator (4). A separator (4) is disposed between the positive electrode (3) and the negative electrode (2), and the positive electrode (3), the negative electrode (2), and the separator (4) are wound or folded to form a battery structure (7). The formed battery structure (7) is housed in a case (5). It may include an electrode tab (70) that serves as an electrical path for inducing the current formed in the battery structure (7) to the outside. An electrolyte is injected into the case (5) and sealed to complete the lithium secondary battery (1). The case (5) is prismatic but is not necessarily limited to this shape and may be, for example, cylindrical, thin film, etc.

[0122] Referring to FIG. 8, a lithium secondary battery (1) according to one embodiment includes a positive electrode (3), a negative electrode (2) and a separator (4) as described above. An electrolyte as described above, including a separator (4), is disposed between the positive electrode (3) and the negative electrode (2) to form a battery structure. For example, the battery structure (7) is stacked in a bicell structure and then housed in a case (5). It may include a positive electrode tab (71) and a negative electrode tab (72) that serve as electrical pathways for inducing current formed in the battery structure (7) to the outside. The electrolyte is injected into the case (5) and sealed to complete the lithium secondary battery (1). The case (5) is prismatic but is not necessarily limited to this shape and may be, for example, cylindrical, thin film, etc.

[0123] However, the present invention is not limited to this, and the case (5) may be configured in various shapes such as circular or pouch type. For example, the pouch-type lithium secondary battery corresponds to the lithium secondary battery (1) of FIGS. 5 to 8 in which a pouch is used as the case (5). The pouch-type lithium secondary battery includes one or more battery structures (7). A separator (4) is disposed between the positive electrode (3) and the negative electrode (2) to form the battery structure (7). The battery structure (7) is stacked in a bicell structure, then impregnated with an electrolyte, and then housed and sealed in a pouch to complete the pouch-type lithium secondary battery.

[0124] Specifically, the battery structure (7) including the aforementioned positive electrode (3), negative electrode (2), and separator (4) is simply stacked and contained in a pouch, or wound into a jelly roll shape or folded and contained in a pouch. Subsequently, an electrolyte is injected into the pouch and sealed to complete the lithium secondary battery (1).

[0125] The case (5) may be made of metal such as aluminum, aluminum alloy, nickel-plated steel, or a laminate film or plastic that constitutes the pouch.

[0126] Lithium secondary battery (1) has excellent lifespan characteristics and high rate characteristics, so it is used in, for example, electric vehicles (EV). For example, it is used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEV). In addition, it is used in fields where a large amount of power storage is required. For example, it is used in electric bicycles, power tools, etc.

[0127] A plurality of lithium secondary batteries (1) are stacked to form a battery module, and a plurality of battery modules form a battery pack. Such a battery pack can be used in any device requiring high capacity and high output. For example, it can be used in laptops, smartphones, electric vehicles, etc. A battery module includes, for example, a plurality of batteries and a frame that holds them.

[0128] A battery pack includes, for example, a plurality of battery modules and a bus bar connecting them. The battery modules and / or battery pack may further include a cooling device. A plurality of battery packs are controlled by a battery management system. The battery management system includes a battery pack and a battery control device connected to the battery pack.

[0129]

[0130] Method for manufacturing a negative electrode for a lithium secondary battery

[0131] FIG. 9 is a flowchart illustrating a method for manufacturing a negative electrode for a lithium secondary battery according to one embodiment of the present disclosure.

[0132] A method (300) for manufacturing a negative electrode for a lithium secondary battery according to one embodiment of the present disclosure may be disclosed by the step (S310) of preparing a negative electrode current collector.

[0133] Next, an electrodeposition-inducing layer containing a conductive polymer can be placed on a negative electrode current collector (S320). The conductive polymer may include PEDOT-TMA. The step of placing the electrodeposition-inducing layer (S320) may include the step of spray-coating a solution containing a conductive polymer on the negative electrode current collector. The content of the conductive polymer may be 0.1 wt% to 15 wt%, or 0.1 wt% to 10 wt%, or 0.1 wt% to 5 wt% based on the total weight of the solution containing the conductive polymer.

[0134] In one embodiment, the conductive polymer may include an anionic dopant. The anionic dopant may include, for example, perchlorate, sulfonate, toluenesulfonate, polystyrene sulfonate, sodium dodecylbenzene sulfonate, or a combination thereof. In one embodiment, the thickness of the electrodeposition-inducing layer may be 0.1 μm or more and 10 μm or less, 0.1 μm or more and 5 μm or less, or 0.1 μm or more and 2 μm or less. Alternatively, the thickness of the electrodeposition-inducing layer may be 0.5 μm or more and 10 μm or less, 0.5 μm or more and 5 μm or less, or 0.5 μm or more and 2 μm or less.

[0135] Next, the cathode current collector on which the electrodeposition-inducing layer is disposed can be immersed in an aqueous solution containing metal ions (S330). The concentration of the aqueous solution containing metal ions may be, for example, 0.1 mM to 20 mM. The time for immersing the cathode current collector on which the electrodeposition-inducing layer is disposed in the aqueous solution containing metal ions may be, for example, 1 hour or less. Metal particles may be formed on the surface of the conductive polymer by reducing the metal ions contained in the aqueous solution by the anionic dopant contained in the conductive polymer. The metal particles may be, for example, metal nanoparticles.

[0136]

[0137] Method for manufacturing lithium secondary batteries

[0138] FIG. 10 is a flowchart illustrating a method for manufacturing a lithium secondary battery according to one embodiment of the present disclosure.

[0139] A method for manufacturing a lithium secondary battery (800) according to one embodiment of the present disclosure may be disclosed with a step (S810) of preparing a negative electrode.

[0140] The step of preparing the cathode (S810) may include the step of placing an electrodeposition-inducing layer on the cathode current collector. The step of placing the electrodeposition-inducing layer may include the step of spray-coating a solution containing a conductive polymer on the cathode current collector. The content of the conductive polymer may be 0.1% to 15% by weight, 0.1% to 10% by weight, or 0.1% to 5% by weight based on the total weight of the solution containing the conductive polymer.

[0141] In one embodiment, the electrodeposition-inducing layer may comprise a conductive polymer having PEDOT (Poly(3,4-ethylenedioxythiophene)). The conductive polymer may comprise, for example, PEDOT (Poly(3,4-ethylenedioxythiophene)), PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate), PEDOT-PSS (Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate), PEDOT-PEG (poly(3,4-ethylenedioxythiophene)-co-poly(ethylene glycol)), or a combination thereof. In one embodiment, the conductive polymer comprises an anionic dopant, and the anionic dopant may comprise perchlorate, sulfonate, p-toluenesulfonate, polystyrene sulfonate, sodium dodecylbenzenesulfonate, or a combination thereof. In one embodiment, the thickness of the electrodeposition-inducing layer may be 0.1 μm or more and 10 μm or less, 0.1 μm or more and 5 μm or less, or 0.1 μm or more and 2 μm or less. Alternatively, the thickness of the electrodeposition-inducing layer may be 0.5 μm or more and 10 μm or less, 0.5 μm or more and 5 μm or less, or 0.5 μm or more and 2 μm or less.

[0142] The step of preparing the cathode (S810) may further include the step of immersing the cathode current collector, on which the electrodeposition-inducing layer is disposed, in an aqueous solution containing silver ions. The aqueous solution containing silver ions may include, for example, an aqueous solution of silver nitrate (AgNO3), an aqueous solution of silver chloride (AgCl), an aqueous solution of silver nitrite (AgNO2), an aqueous solution of silver sulfate (Ag2SO4), or a combination thereof. The concentration of the aqueous solution containing silver ions may be, for example, 0.1 mM to 30 mM. The time for immersing the cathode current collector, on which the electrodeposition-inducing layer is disposed, in the aqueous solution containing silver ions may be, for example, 1 hour or less. Silver particles may be formed on the surface of the conductive polymer by reducing the silver ions contained in the aqueous solution by an anionic dopant contained in the conductive polymer. Silver particles can act as nucleation seeds during the process of lithium deposition on the negative electrode when charging a secondary battery, thereby reducing the nucleation over-potential.

[0143] Next, a positive electrode can be prepared (S820). The step of preparing the positive electrode (S820) may include the step of placing a positive electrode composite on a positive electrode current collector. In one embodiment, the positive electrode composite may include a positive electrode active material and a sacrificial positive electrode active material. The positive electrode active material may include, for example, LiMO2 (M is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof), LiFePO4, LiM2O4 (M is Ti, V, Mn, or a combination thereof), or a combination thereof. The sacrificial positive electrode active material may include, for example, Li5FeO4, Li2MoO3, Li6CoO4, Li2O, Li3N, Li3P, or a combination thereof.

[0144] Next, an electrolyte may be placed between the anode and the cathode (S830). The electrolyte may include an organic solvent and a lithium salt. The electrolyte may further include a crosslinking agent to form a polymer matrix.

[0145]

[0146] anode

[0147] Referring to FIGS. 1 and 2, an anode composite part (160) may be disposed on an anode current collector (150) to form an anode (140). For example, an anode composite part (160) may be disposed on an electrolyte (170), and an anode current collector (150) may be disposed on the anode composite part (160).

[0148]

[0149] positive electrode active material

[0150] Referring to FIG. 1 and FIG. 2, a lithium secondary battery (100) according to one embodiment of the present disclosure may include a positive current collector (150) and a positive composite portion (160) disposed on the positive current collector (150). The positive composite portion (160) may include a positive active material.

[0151] As a positive electrode active material, a compound capable of reversible intercalation and deintercalation of lithium (a lithated intercalation compound) may be used. Specifically, one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used. The composite oxide may be a lithium transition metal composite oxide, and specific examples include a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0152] As an example, a compound represented by any one of the following chemical formulas may be used. Li a A 1-b X b O 2-c D c(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05), Li a Mn 2-b X b About 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05), Li a Ni 1-b-c Co b X c About 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2), Li a Ni 1-b-c Mn b X c About 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2), Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1), Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1), Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1), Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1), Li a Mn2GbO4(0.90≤a≤1.8, 0.001≤b≤0.1), Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5), Li (3-f) Fe2(PO4)3(0≤f≤2), Li a FePO4(0.90≤a≤1.8).

[0153] In the chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L 1 is Mn, Al, or a combination thereof.

[0154] For example, the cathode active material may be a high-nickel cathode active material in which the nickel content relative to 100 mol% of the metal excluding lithium in a lithium transition metal composite oxide is 80 mol% or more, 85 mol% or more, 90 mol% or more, 91 mol% or more, or 94 mol% or more and 99 mol% or less. The high-nickel cathode active material can achieve high capacity and can be applied to high-capacity, high-density lithium secondary batteries.

[0155] For example, the lithium transition metal oxide may be a compound represented by the following chemical formula 1:

[0156]

[0157] <Chemical Formula 1>

[0158] Li a Ni x Co y M z O 2-b A b

[0159]

[0160] In Chemical Formula 1, 1.0≤a≤1.2, 0≤b≤0.2, 0.6≤x<1, 0≤y≤0.3, 0 <z≤0.3, x+y+z=1, M은 망간(Mn), 바나듐(V), 마그네슘(Mg), 갈륨(Ga), 실리콘(Si), 텅스텐(W), 몰리브덴(Mo), 철(Fe), 크롬(Cr), 구리(Cu), 아연(Zn), 티타늄(Ti), 알루미늄(Al) 및 보론(B)으로 이루어진 군으로부터 선택된 하나 이상이고, A는 F, S, Cl, Br 또는 이들의 조합이다.

[0161] In Chemical Formula 1, for example, 0.7≤x<1, 0 <y≤0.3, 0<z≤0.3, 0.8≤x<1, 0<y≤0.2, 0<z≤0.2, 0.83≤x<0.97, 0<y≤0.15, 0<z≤0.15, 또는 0.85≤x<0.95, 0<y≤0.1, 0<z≤0.1일 수 있다.

[0162] For example, the lithium transition metal oxide may be at least one of the compounds represented by the following chemical formulas 2 and 3:

[0163]

[0164] <Chemical Formula 2>

[0165] LiNi x Co y Mn z O2

[0166]

[0167] In Chemical Formula 2, 0.6≤x≤0.95, 0 <y≤0.2, 0<z≤0.1이다. 예를 들어, 0.7≤x≤0.95, 0<y≤0.3, 0<z≤0.3이다.

[0168]

[0169] <Chemical Formula 3>

[0170] LiNi x Co y Al z O2

[0171]

[0172] In Chemical Formula 3, 0.6≤x≤0.95, 0 <y≤0.2, 0<z≤0.1이다. 예를 들어, 0.7≤x≤0.95, 0<y≤0.3, 0<z≤0.3이다. 예를 들어, 0.8≤x≤0.95, 0<y≤0.3, 0<z≤0.3이다. 예를 들어, 0.82≤x≤0.95, 0<y≤0.15, 0<z≤0.15이다. 예를 들어, 0.85≤x≤0.95, 0<y≤0.1, 0<z≤0.1이다.

[0173] For example, lithium transition metal oxides are LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.88 Co 0.08Mn 0.04O2 , LiNi 0.8 Co 0.15 Mn 0.05O2 , LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.88 Co 0.1 Mn 0.02O2 , LiNi 0.8 Co 0.15 Al 0.05O2 , LiNi 0.8 Co 0.1 Mn 0.2O2 or LiNi 0.88 Co 0.1 Al 0.02O2 It could be.

[0174] For example, the positive electrode active material may be one having a coating layer on the surface of a lithium transition metal oxide, or a mixture of a lithium transition metal oxide and a lithium transition metal oxide having a coating layer may be used.

[0175] For example, the coating layer may include a coating element compound of an oxide, hydroxide, oxyhydroxide, oxycarbonate, or hydroxycarbonate of a coating element.

[0176] For example, the compound forming the coating layer may be amorphous or crystalline. The coating elements included in the coating layer may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. For the coating layer formation process, any coating method may be used as long as the coating can be applied to the lithium transition metal oxide using the coating elements in a manner that does not adversely affect the physical properties of the cathode active material (e.g., spray coating, immersion method, etc.).

[0177] In one embodiment, the sacrificial cathode active material may include Li5FeO4, Li2MoO3, Li6CoO4, Li2O, Li3N, Li3P, or a combination thereof. In the cathode composite part (160), the capacity ratio between the cathode active material and the sacrificial cathode active material may be 1:1 to 9:1.

[0178] In one embodiment, the sacrificial cathode active material included in the positive electrode (140) can form a lithium metal layer (180) on the negative electrode (110) during the formation stage of the manufacturing process of the lithium secondary battery (100). Through this process, the lifespan characteristics of the secondary battery can be significantly improved by compensating for irreversible lithium consumption caused by SEI generation or other side reactions during the charging and discharging of the lithium secondary battery (100).

[0179]

[0180] Positive: Positive current collector

[0181] Referring to FIGS. 1 and 2, the anode (140) includes an anode current collector (150). For example, the anode (140) can be prepared by forming an anode composite part (160) on the anode current collector (150).

[0182] For example, the positive current collector (150) may include indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof.

[0183] According to one embodiment, the positive current collector (150) may include aluminum (Al).

[0184] In one embodiment, the positive current collector (150) may include a base film and a metal substrate layer disposed on one or both sides of the base film, in the same manner as the negative current collector (120) described later.

[0185]

[0186] Cathode: Cathode current collector

[0187] Referring to FIGS. 1, 2 and 3, the negative current collector (120) may not include a negative active material layer. In the negative current collector (120) that does not include a negative active material layer, lithium metal may be plated onto the negative current collector (120) by charging. The plated metal layer may include plated lithium, lithium metal foil, lithium metal powder, lithium alloy foil, lithium alloy powder, an organic compound containing lithium, or a combination thereof. The metal layer may include non-fibrous lithium, non-needle lithium, plate lithium, or any combination thereof. The lithium alloy contains lithium and a first metal, and the first metal may include indium (In), silicon (Si), gallium (Ga), tin (Sn), aluminum (Al), titanium (Ti), zirconium (Zr), niobium (Nb), germanium (Ge), antimony (Sb), bismuth (Bi), gold (Au), platinum (Pt), palladium (Pd), magnesium (Mg), silver (Ag), zinc (Zn), nickel, iron, cobalt, chromium, cesium, sodium, potassium, calcium, yttrium, bismuth, tantalum, hafnium, barium, vanadium, strontium, lanthanum, or a combination thereof.

[0188] The material constituting the negative electrode current collector (120) can be any material that does not react with lithium, that is, a material that does not form an alloy or compound with lithium and has conductivity. The metal substrate is, for example, a metal or an alloy. The metal substrate may be, for example, made of indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof. The electrode current collector may have a shape selected from, for example, a sheet, foil, film, plate, porous body, mesoporous body, through-hole containing body, polygonal ring body, mesh body, foam, and nonwoven body, but is not necessarily limited to these shapes and any shape used in the relevant technical field is possible.

[0189] The negative current collector (120) includes, for example, a first metal substrate. The first metal substrate includes the first metal as a main component or is made of the first metal. The first metal substrate includes the first metal as a main component or is made of the first metal. The content of the first metal included in the first metal substrate is, for example, 90 weight% or more, 95 weight% or more, 99 weight% or more, or 99.9 weight% or more with respect to the total weight of the first metal substrate. The first metal substrate may be composed of, for example, a material that does not react with lithium, that is, does not form an alloy and / or compound with lithium.

[0190] The first metal may be, for example, copper (Cu), nickel (Ni), stainless steel (SUS), iron (Fe), and cobalt (Co), but is not necessarily limited to these; any metal used as a current collector in the relevant technical field may be used. The first metal substrate may be composed of, for example, one of the metals described above, or may be composed of an alloy of two or more metals. The first metal substrate is, for example, in the form of a sheet or foil.

[0191] The negative current collector (120) may further include a coating layer (not shown) containing a second metal on a first metal substrate.

[0192] The negative current collector (120) may include, for example, a first metal substrate and a coating layer disposed on the first metal substrate and containing a second metal. The second metal has a higher Mohs hardness than the first metal. That is, since the coating layer containing the second metal is harder than the substrate containing the first metal, deterioration of the first metal substrate can be prevented. The Mohs hardness of the material constituting the first metal substrate is, for example, 5.5 or less. The Mohs hardness of the first metal is, for example, 5.5 or less, 5.0 or less, 4.5 or less, 4.0 or less, 3.5 or less, or 3.0 or less. The Mohs hardness of the first metal may be, for example, 2.0 to 6.0. The coating layer contains the second metal. The coating layer may, for example, contain the second metal as a main component or be composed of the second metal. The content of the second metal included in the coating layer is, for example, 90% by weight or more, 95% by weight or more, 99% by weight or more, or 99.9% by weight or more with respect to the total weight of the coating layer. The coating layer may be composed of, for example, a material that does not react with lithium, that is, does not form an alloy and / or compound with lithium. The Mohs hardness of the material constituting the coating layer is, for example, 6.0 or more. For example, the Mohs hardness of the second metal is 6.0 or more, 6.5 or more, 7.0 or more, 7.5 or more, 8.0 or more, 8.5 or more, or 9.0 or more. The Mohs hardness of the second metal may be, for example, 6.0 to 12. If the Mohs hardness of the second metal is excessively low, it may be difficult to suppress the deterioration of the negative electrode current collector (120). If the Mohs hardness of the second metal is excessively high, processing may not be easy. The second metal is one or more selected from, for example, titanium (Ti), manganese (Mn), niobium (Nb), tantalum (Ta), iridium (Ir), vanadium (V), rhenium (Re), osmium (Os), tungsten (W), chromium (Cr), boron (B), ruthenium (Ru), and rhodium (Rh).The coating layer may be composed of, for example, one of the metals described above, or an alloy of two or more metals. The difference in Mohs hardness between the first metal included in the first metal substrate and the second metal included in the coating layer may be, for example, 2 or more, 2.5 or more, 3 or more, 3.5 or more, or 4 or more. By having such a difference in Mohs hardness between the first metal and the second metal, the deterioration of the negative current collector (120) can be suppressed more effectively. The coating layer may be a single-layer structure or a multilayer structure of two or more layers. The coating layer may be a two-layer structure including, for example, a first coating layer and a second coating layer. The coating layer may be a three-layer structure including, for example, a first coating layer, a second coating layer, and a third coating layer. The thickness of the coating layer may be, for example, 10 nm to 1 μm, 50 nm to 500 nm, 50 nm to 200 nm, or 50 nm to 150 nm. The coating layer may be deposited on the first metal substrate by, for example, vacuum deposition, sputtering, plating, etc., but is not necessarily limited to these methods; any method capable of forming a coating layer in the relevant technical field is possible.

[0193] For example, the negative current collector (120) may have a reduced thickness compared to a conventional negative current collector. Accordingly, the negative electrode (110) according to the present disclosure is distinguished from a conventional electrode comprising a thick film current collector by including, for example, a thin film current collector.

[0194] As a result, the energy density of the lithium metal secondary battery employing such electrodes is increased. The thickness of the negative electrode current collector (120) may be, for example, less than 15 μm, 14.5 μm or less, or 14 μm or less. The thickness of the negative electrode current collector (120) may be, for example, 0.1 μm to 15 μm, 1 μm to 14.5 μm, 2 μm to 14 μm, 3 μm to 14 μm, 5 μm to 14 μm, or 10 μm to 14 μm.

[0195] The negative current collector (120) may have a shape selected from, for example, a sheet, foil, film, plate, porous body, mesoporous body, through-hole containing body, polygonal ring body, mesh body, foam, and nonwoven body, but is not necessarily limited to these shapes and any shape used in the relevant technical field is possible.

[0196] The negative current collector (120) may include, for example, a base film and a metal substrate layer disposed on one or both sides of the base film. The negative current collector (120) may have a structure comprising a substrate, wherein the substrate may include, for example, a base film and a metal substrate layer disposed on one or both sides of the base film. An intermediate layer may be additionally disposed on the metal substrate layer.

[0197] For example, the base film may include, for example, a polymer. The polymer may be, for example, a thermoplastic polymer. The polymer may include, for example, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), polyimide (PI), or a combination thereof. By including a thermoplastic polymer in the base film, the base film may melt upon the occurrence of a short circuit, thereby suppressing a sudden increase in current. The base film may be, for example, an insulator.

[0198] The metal substrate layer may include, for example, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), or alloys thereof. The metal substrate layer may act as an electrochemical fuse and be cut off in the event of an overcurrent to perform a short-circuit prevention function. The limit current and maximum current can be controlled by adjusting the thickness of the metal substrate layer. The metal substrate layer may be plated or deposited on a base film. As the thickness of the metal substrate layer decreases, the limit current and / or maximum current of the negative electrode current collector (120) decreases, thereby improving the stability of the lithium metal secondary battery in the event of a short circuit.

[0199] A lead tab may be added to the metal substrate layer for external connection. The lead tab may be welded to the metal substrate layer or the metal substrate layer / base film laminate by means of ultrasonic welding, laser welding, spot welding, etc. During welding, the base film and / or the metal substrate layer may melt, thereby electrically connecting the metal substrate layer to the lead tab. To make the weld between the metal substrate layer and the lead tab more robust, a metal chip may be added between the metal substrate layer and the lead tab. The metal chip may be a thin sheet of the same material as the metal of the metal substrate layer. The metal chip may be, for example, metal foil, metal mesh, etc. The metal chip may be, for example, aluminum foil, copper foil, SUS foil, etc. The lead tab may be welded to the metal chip / metal substrate layer laminate or the metal chip / metal substrate layer / base film laminate by placing the metal chip on the metal substrate layer and then welding it to the lead tab. During welding, the base film, metal layer, and / or metal chip may melt, allowing the metal layer or the metal layer / metal chip laminate to be electrically connected to the lead tab. A metal chip and / or lead tab may be added to a portion of the metal substrate layer. The thickness of the base film may be, for example, 1 μm to 50 μm, 1.5 μm to 50 μm, 1.5 μm to 40 μm, or 1 μm to 30 μm. By having the base film within this range of thickness, the weight of the cathode assembly can be reduced more effectively. The melting point of the base film may be, for example, 100° to 300° (Celsius), 100° to 250° (Celsius) or lower, or 100° to 200° (Celsius). By having the base film within this range of melting point, the base film can melt during the welding process of the lead tab and be easily bonded to the lead tab. To improve the adhesion between the base film and the metal substrate layer, a surface treatment such as corona treatment may be performed on the base film.The thickness of the metal substrate layer may be, for example, 0.01 μm to 3 μm, 0.1 μm to 3 μm, 0.1 μm to 2 μm, or 0.1 μm to 1 μm. By having the metal substrate layer within this range of thickness, the stability of the cathode can be ensured while maintaining conductivity. The thickness of the metal piece may be, for example, 2 μm to 10 μm, 2 μm to 7 μm, or 4 μm to 6 μm. By having the metal piece within this range of thickness, the connection between the metal layer and the lead tab can be performed more easily. By having the cathode current collector (120) with this structure, the weight of the electrode can be reduced and, consequently, the energy density can be improved.

[0200] According to one embodiment, a negative active material layer may be free on the negative current collector (120) before charging and discharging. For example, a lithium metal layer (180) may be free on the negative current collector (120) before charging and discharging.

[0201] According to one embodiment, a lithium metal layer including a plate-shaped lithium metal thin film may be disposed on a negative electrode current collector (120) before performing charging and discharging.

[0202]

[0203] electrolytes

[0204] The electrolyte (170) may be, for example, a liquid electrolyte, a solid electrolyte, a gel electrolyte, or a combination thereof.

[0205] The electrolyte (170) is, for example, an organic electrolyte. The organic electrolyte is prepared, for example, by dissolving a lithium salt in an organic solvent. Any organic solvent used as an organic solvent in the relevant technical field is acceptable. For example, the organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, an aprotic solvent, or a combination thereof.

[0206] Carbonate-based solvents such as fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methyl ethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), and butylene carbonate (BC) may be used.

[0207] Ester-based solvents such as methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methylpropionate, ethylpropionate, decanolide, mevalonolactone, valerolactone, and caprolactone may be used.

[0208] Dibutyl ether, tetraglame, diglame, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, etc. can be used as ether-based solvents.

[0209] Cyclohexanone and the like can be used as ketone-based solvents. Ethyl alcohol and isopropyl alcohol and the like can be used as alcohol-based solvents, and nitriles such as R-CN (where R is a straight-chain, branched, or cyclic hydrocarbon group having 2 to 20 carbon atoms and may include a double bond, an aromatic ring, or an ether group) and amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane and 1,4-dioxolane; and sulfolanes and the like can be used as aprotic solvents.

[0210] Any lithium salt used as a lithium salt in the relevant technical field is also acceptable. For example, the lithium salt may include lithium hexafluorophosphate (LiPF6), lithium difluoro(oxalato)borate (LiDFOB), lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), or a combination thereof.

[0211] Solid electrolytes are, for example, oxide-based solid electrolytes, sulfide-based solid electrolytes, polymeric solid electrolytes, or combinations thereof.

[0212] Solid electrolytes are, for example, oxide-based solid electrolytes. Oxide-based solid electrolytes are Li 1+x+y Al x Ti 2-x Si y P 3-y O 12 (0 <x<2, 0≤y<3), BaTiO3, Pb(Zr,Ti)O3(PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT)(O≤x<1, O≤y<1), PB(Mg3Nb 2 / 3 )O3-PbTiO3(PMN-PT), HfO2, SrTiO3, SnO2, CeO2, Na2O, MgO, NiO, CaO, BaO, ZnO, ZrO2, Y2O3, Al2O3, TiO2, SiO2, Li3PO4, Li x Ti y (PO4)3(0 <x<2, 0<y<3), Li x Al y Ti z (PO4)3(0 <x<2, 0<y<1, 0<z<3), Li 1+x+y (Al, Ga) x (Ti, Ge) 2-x Siy P 3-y O 12 (0≤x≤1 0≤y≤1), Li x La y TiO3(0 <x<2, 0<y<3), Li2O, LiOH, Li2CO3, LiAlO2, Li2O-Al2O3-SiO2-P2O5-TiO2-GeO2, Li 3+x La3M2O 12 It is one or more selected from (M = Te, Nb, or Zr, where x is an integer from 1 to 10). Solid electrolytes are produced by sintering methods, etc. For example, oxide-based solid electrolytes include Li7La3Zr2O 12 (LLZO) and Li 3+x La3Zr 2-a MaO 12 It is a garnet-type solid electrolyte selected from (M doped LLZO, M=Ga, W, Nb, Ta, or Al, x is an integer from 1 to 10).

[0213] Sulfide-based solid electrolytes may comprise, for example, lithium sulfide, silicon sulfide, phosphorus sulfide, boron sulfide, or combinations thereof. Sulfide-based solid electrolyte particles may comprise Li2S, P2S5, SiS2, GeS2, B2S3, or combinations thereof. Sulfide-based solid electrolyte particles may be Li2S or P2S5. Sulfide-based solid electrolyte particles have high lithium ion conductivity compared to other inorganic compounds. For example, sulfide-based solid electrolytes comprise Li2S and P2S5. When the sulfide solid electrolyte material constituting the sulfide-based solid electrolyte comprises Li2S-P2S5, the mixed molar ratio of Li2S to P2S5 may be, for example, in the range of about 50:50 to about 90:10. Additionally, Li3PO4, halogens, halogen compounds, Li 2+2x Zn 1-x GeO4("LISICON", 0≤x<1), Li 3+y PO 4-x N x("LIPON", 0 <x<4, 0<y<3), Li 3.25 Ge 0.25 P 0.75 An inorganic solid electrolyte prepared by adding S4 ("ThioLISICON"), Li2O-Al2O3-TiO2-P2O5 ("LATP"), etc., to an inorganic solid electrolyte of Li2S-P2S5, SiS2, GeS2, B2S3, or a combination thereof can be used as a sulfide solid electrolyte. Non-limiting examples of sulfide solid electrolyte materials include Li2S-P2S5, Li2S-P2S5-LiX (X = halogen element), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-ZmSn (0 <m<10, 0<n<10, Z=Ge, Zn 또는 Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, 및 Li2S-SiS2-Li p MO q (0 <p<10, 0<q<10, M=P, Si, Ge, B, Al, Ga 또는 In)을 포함한다. 이와 관련하여, 황화물계 고체전해질 재료는 황화물계 고체전해질 물질의 원료 시작 물질(예를 들면, Li2S, P2S5, 등)을 용융 담금질법(melt quenching method), 기계적 밀링법 등에 의해 처리함으로써 제조될 수 있다.

[0214] In addition, a calcination process may be performed after the above treatment. The sulfide-based solid electrolyte may be amorphous, crystalline, or a mixture thereof.

[0215] Polymer solid electrolytes are electrolytes that, for example, contain a mixture of a lithium salt and a polymer, or contain a polymer having ion-conducting functional groups. Polymer solid electrolytes are, for example, polymer electrolytes that do not contain a liquid electrolyte. The polymers included in the polymeric solid electrolyte are, for example, polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyethylene oxide (PEO), poly(styrene-b-ethylene oxide) block copolymer (PS-PEO), poly(styrene-butadiene), poly(styrene-isoprene-styrene), poly(styrene-b-divinylbenzene) block copolymer, poly(styrene-ethylene oxide-styrene) block copolymer, polystyrene sulfonate (PSS), polyvinyl fluoride (PVF), poly(methylmethacrylate) (PMMA), polyethylene glycol (PEG), polyacrylonitrile (PAN), polytetrafluoroethylene (PTFE), polyethylenedioxythiophene (PEDOT), polypyrrole (PPY), polyacrylonitrile (PAN), Polyaniline, Polyacetylene, Nafion, Aquivion, Flemion, Gore, Aciplex, Morgane ADP, Sulfonated poly, (ether ether ketone)(sulfonated poly(ether ether ketone), SPEEK), Sulfonated poly(arylene ether ketone ketone sulfone)(sulfonated poly(aryl ether ketone, SPAEK), Poly[bis(benzimidazobenzisoquinolinones)](poly[bis(benzimidazobenzisoquinolinones)], SPBIBI), Poly(styrene sulfonate)(Poly(styrene sulfonate), PSS), Lithium 9,It may be 10-diphenylanthracene-2-sulfonate (lithium 9,10-diphenylanthracene-2-sulfonate, DPASLi+) or a combination thereof, but is not limited thereto, and any that is used as a polymer electrolyte (170) in the art is possible. Any lithium salt that can be used as a lithium salt in the art is possible. For example, lithium salts include LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, Li(CF3SO2)2N, LiC4F9SO3, LiAlO2, LiAlCl4, LiN(C, x F 2x+1 SO2)(C y F 2y+1 SO2)(x and y are each 1 to 20), LiCl, LiI, or mixtures thereof, etc.

[0216] A gel electrolyte is, for example, a gel polymer electrolyte. A gel polymer electrolyte is an electrolyte that includes, for example, a liquid electrolyte and a polymer, or includes an organic solvent and a polymer having ion-conducting functional groups. The liquid electrolyte may be, for example, an ionic liquid, a mixture of a lithium salt and an organic solvent, a mixture of an ionic liquid and an organic solvent, or a mixture of a lithium salt, an ionic liquid, and an organic solvent. The polymer may be selected from among the polymers used in solid polymer electrolytes. The organic solvent may be selected from among the organic solvents used in liquid electrolytes. The lithium salt may be selected from among the lithium salts used in solid polymer electrolytes. An ionic liquid refers to a salt in a liquid state at room temperature or a room temperature molten salt that has a melting point below room temperature and consists solely of ions. The ionic liquid comprises, for example, a) one or more cations selected from ammonium, pyrrolidinium, pyridinium, pyrimidinium, imidazolium, piperidinium, pyrazolium, oxazolium, pyridazinium, phosphonium, sulfonium, triazolium, and mixtures thereof, and b) BF4 - , PF6 - , AsF6- , SbF6 - , AlCl4 - , HSO4 - , ClO4 - , CH3SO3 - , CF3CO2 - , Cl - , Br - , I - , BF4 - , SO4 - , CF3SO3 - , (FSO2)2N - , (C2F5SO2)2N - , (C2F5SO2)(CF3SO2)N - , and (CF3SO2)2N - It may include one or more compounds selected from those containing one or more anions selected from among. A gel polymer electrolyte may be formed by impregnating the polymer solid electrolyte into the electrolyte in a lithium secondary battery. The gel electrolyte may further include inorganic particles.

[0217]

[0218] separator

[0219] A lithium secondary battery (100) according to one embodiment may further include a separator (not shown).

[0220] As a separator, polyethylene, polypropylene, polyvinylidene fluoride, or multilayer films of two or more layers thereof may be used, and of course, mixed multilayer films such as polyethylene / polypropylene two-layer separator, polyethylene / polypropylene / polyethylene three-layer separator, polypropylene / polyethylene / polypropylene three-layer separator may be used.

[0221] The separator may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof located on one or both sides of the porous substrate.

[0222] The porous substrate may be a polymer membrane formed from any one of the following: polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyacetal; polyamide; polyimide; polycarbonate; polyetherketone; polyaryletherketone; polyetherimide; polyamideimide; polybenzimidazole; polyethersulfone; polyphenylene oxide; cyclic olefin copolymer; polyphenylene sulfide; polyethylene naphthalate; glass fiber; Teflon; and polytetrafluoroethylene, or a copolymer or mixture of two or more of these.

[0223] The organic material may include a polyvinylidene fluoride-based polymer or a (meth)acrylic-based polymer.

[0224] The inorganic material may include, but is not limited to, inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0225] Organic and inorganic materials may exist mixed in a single coating layer, or may exist in a stacked form with a coating layer containing organic materials and a coating layer containing inorganic materials.

[0226] This will be explained in more detail through the following examples and comparative examples. However, the examples are for illustrative purposes only and are not limited thereto.

[0227]

[0228] Example A-1

[0229] (Anode manufacturing)

[0230] Aluminum foil was prepared as the positive current collector. A positive electrode was manufactured by applying a slurry of the positive electrode composite containing a positive electrode active material, a conductive material, and a binder onto the aluminum foil and then drying it. A lithium cobalt oxide (LCO) active material was used as the positive electrode active material. The positive electrode was manufactured such that the content of the conductive material and the binder were 2% and 1%, respectively, based on the weight of the positive electrode composite.

[0231] (Cathode manufacturing)

[0232] A copper foil was prepared as the cathode current collector, and a conductive polymer solution containing PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate) was prepared. The conductive polymer solution was prepared by mixing 0.5 wt% of PEDOT-TMA and 99.5 wt% of a solvent based on the weight of the solution. Nitromethane was used as the solvent. The conductive polymer contained in the solution was prepared to include p-toluenesulfonate as an anionic dopant. Subsequently, an electrodeposition-inducing layer was formed by spray coating the conductive polymer solution onto the cathode current collector using an airbrush connected to Ar gas. The diameter of the spray nozzle of the airbrush used for spray coating was 0.2 mm. The thickness of the electrodeposition-inducing layer formed after the solvent evaporated following spray coating was set to 2 μm. Subsequently, a cathode current collector having an electrodeposition-inducing layer containing PEDOT-TMA was immersed in a 1 mM aqueous solution of silver nitrate (AgNO3) for 10 minutes to form silver particles on the surface of a conductive polymer.

[0233] (Lithium secondary battery manufacturing)

[0234] A polyolefin-based separator was used.

[0235] A gel polymer electrolyte was used. The gel polymer electrolyte was prepared as follows. Fluoroethylene carbonate (FEC) and diethyl carbonate (DEC) were mixed in an organic solvent in a volume ratio of 1:2. Subsequently, a liquid electrolyte was prepared by dissolving 0.6 M each of the lithium salts LiDFOB and LiBF4 in the organic solvent. The polymer monomer DPHA was dissolved in the liquid electrolyte to achieve a ratio of liquid electrolyte to DPHA = 95:5 (w:w), and a radical initiator was added to prepare an electrolyte precursor.

[0236] An electrode assembly was prepared by sequentially stacking a cathode, a separator, and an anode, and an electrolyte precursor was injected. Subsequently, a lithium secondary battery was prepared by thermal crosslinking.

[0237]

[0238] Example A-2

[0239] As indicated in Table 1, a lithium secondary battery was manufactured in the same manner as in Example A-1, except that an aqueous solution of magnesium nitrate (Mg(NO3)2) was used as the aqueous solution containing metal ions.

[0240]

[0241] Example A-3

[0242] As indicated in Table 1, a lithium secondary battery was manufactured in the same manner as in Example A-1, except that an aqueous solution of zinc nitrate (Zn(NO3)2) was used as the aqueous solution containing metal ions.

[0243]

[0244] Example A-4

[0245] As indicated in Table 1, a lithium secondary battery was manufactured in the same manner as in Example A-1, except that an aqueous solution of aluminum nitrate (Al(NO3)3) was used as the aqueous solution containing metal ions.

[0246]

[0247] Example A-5

[0248] As indicated in Table 1, a lithium secondary battery was manufactured in the same manner as in Example A-1, except that an aqueous solution of tin octoate (Sn(Oct)2) was used as the aqueous solution containing metal ions.

[0249]

[0250] Comparative Example A-1

[0251] As indicated in Table 1, a lithium secondary battery was manufactured in the same manner as in Example A-1, except that a conductive polymer containing PEDOT-PEG was used and a perchlorate was used as an anion dopant.

[0252]

[0253] Comparative Example A-2

[0254] As indicated in Table 1, a lithium secondary battery was prepared in the same manner as in Example A-1, except that a conductive polymer containing PEDOT-PSS was used, polystyrene sulfonate was used as the anionic dopant, and the solvent of the conductive polymer solution was H2O.

[0255]

[0256] Comparative Example A-3

[0257] As indicated in Table 1, a lithium secondary battery was prepared in the same manner as in Example A-1, except that a conductive polymer containing PEDOT was used, sodium dodecylbenzenesulfonate was used as the anionic dopant, and the solvent of the conductive polymer solution was H2O.

[0258]

[0259] Comparative Example A-4

[0260] As indicated in Table 1, a lithium secondary battery was manufactured in the same manner as in Example A-1, except that a conductive polymer containing PEDOT-PEG was used, the negative current collector on which the electrodeposition inducing layer is disposed was not immersed in an aqueous solution containing metal ions, and the conductive polymer did not contain an anion dopant.

[0261]

[0262] Comparative Example A-5

[0263] As indicated in Table 1, a lithium secondary battery was manufactured in the same manner as in Example A-1, except that a conductive polymer containing PEDOT-PSS was used, the negative current collector on which the electrodeposition inducing layer is disposed was not immersed in an aqueous solution containing metal ions, the conductive polymer did not contain an anionic dopant, and the solvent of the conductive polymer solution was H2O.

[0264]

[0265] Comparative Example A-6

[0266] As indicated in Table 1, a lithium secondary battery was manufactured in the same manner as in Example A-1, except that a conductive polymer containing PEDOT was used, the negative current collector on which the electrodeposition inducing layer is disposed was not immersed in an aqueous solution containing metal ions, the conductive polymer did not contain an anionic dopant, and the solvent of the conductive polymer solution was H2O.

[0267]

[0268] Comparative Example A-7

[0269] As indicated in Table 1, a lithium secondary battery was prepared in the same manner as Example A-1, except that an electrodeposition-inducing layer was not formed on the negative current collector, the negative current collector was not immersed in an aqueous silver nitrate (AgNO3) solution, and there was no anionic dopant or solvent.

[0270]

[0271] Solvent of anionic dopant polymer solution containing aqueous solution containing metal ions for selective conductive polymers Examples A-1 PEDOT-TMAAgNO3p-toluenesulfonate nitromethane Example A-2 PEDOT-TMAMg(NO3)2p-toluenesulfonate nitromethane Example A-3 PEDOT-TMAZn(NO3)2p-toluenesulfonate nitromethane Example A-4 PEDOT-TMAAl(NO3)3p-toluenesulfonate nitromethane Example A-5 PEDOT-TMASn(Oct)2p-toluenesulfonate nitromethane Comparative Example A-1 PEDOT-PEGAgNO3 and chlorate nitromethane Comparative Example A-2 PEDOT-PSSAgNO3 polystyrene sulfonate H2O Comparative Example A-3 PEDOTAgNO3 dodecylbenzene sulfonate sodium H2O A-4 PEDOT-PEG--Nitromethane Comparative Example A-5 PEDOT-PSS--H2O Comparative Example A-6 PEDOT--H2O Comparative Example A-7----

[0272] Evaluation Example A-1: ​​Measurement of Dose Retention Rate (%, @100cy)

[0273] For the lithium secondary battery prepared according to the examples and comparative examples, constant current charging was performed at 45°C at a current rate of 0.1C until the voltage reached 4.5V (vs. Li), and then cut-off was performed at a current rate of 0.05C while maintaining 4.5V in constant voltage mode. Subsequently, during discharge, the battery was discharged at a constant current rate of 0.1C until the voltage reached 2.8V (vs. Li) (formation stage, 1st cycle).

[0274] The formation process was completed by performing this charge-discharge process once.

[0275] A lithium secondary battery that has undergone the formation stage was charged at 45°C with a constant current of 0.33C in a voltage range of 2.8 to 4.5 V relative to lithium metal, and then cut off at a current rate of 0.05C while maintaining 4.5V in constant voltage mode. Subsequently, constant current discharge was performed at 1.0C until a cut-off voltage of 2.8V was reached. The aforementioned charge-discharge process was repeated a total of 100 times. In all charge-discharge cycles, a 5-minute pause was observed after each charge / discharge cycle. Here, the capacity retention rate in the Nth cycle is defined by the following Equation A-1.

[0276]

[0277] [Formula A-1]

[0278] Capacity Retention Rate (%) = (Discharge capacity at the Nth cycle / 1 st Discharge capacity per cycle) × 100

[0279]

[0280] The capacity retention rate at the 100th cycle for each is listed in Table 2.

[0281]

[0282] Evaluation Example A-2: Measurement of nucleation over-potential

[0283] A cell was constructed using a negative electrode for a lithium secondary battery prepared according to the examples and comparative examples, using Li metal as the counter electrode, and adding a separator to prevent a short circuit between the two electrodes. Subsequently, 1.0 mA / cm² 2 Li was deposited on the cathode at a current density, and the lithium nucleation over-potential was analyzed using the voltage profile measured at that time, and the results are shown in Fig. 11.

[0284]

[0285] Classification Capacity Retention Rate (%, @100cy) Example A-1 (Ag-doped) 84.7 Example A-2 (Mg-doped) 82.5 Example A-3 (Zn-doped) 81.1 Example A-4 (Al-doped) 79.9 Example A-5 (Sn-doped) 79.2 Comparative Example A-1 75.0 Comparative Example A-2 72.5 Comparative Example A-3 71.2 Comparative Example A-4 73.8 Comparative Example A-5 70.6 Comparative Example A-6 69.5 Comparative Example A-7 64.9

[0286] Referring to Table 2, it can be seen that when an electrodeposition inducing layer containing metal particles and PEDOT-TMA is placed on a negative current collector, it has a higher capacity retention rate than a comparative example in which an electrodeposition inducing layer is not included or an electrodeposition inducing layer containing a different type of conductive polymer is placed.

[0287] Referring to Fig. 11, it can be seen that when an electrodeposition-inducing layer containing metal particles and PEDOT-TMA is placed on a negative current collector, the nucleation over-potential is reduced compared to a comparative example containing a different type of polymer as the conductive polymer.

[0288]

[0289] Example B-1

[0290] (Anode manufacturing)

[0291] Aluminum foil was prepared as the positive current collector. A positive electrode was manufactured by applying a slurry of a positive electrode composite containing a positive electrode active material and a sacrificial positive electrode active material onto the aluminum foil and then drying it. Lithium cobalt oxide (LCO) was used as the positive electrode active material, and lithium iron oxide (LFO) was used as the sacrificial positive electrode active material. The positive electrode was manufactured such that the capacity ratio between the positive electrode active material and the sacrificial positive electrode active material was 2:1. The content of the conductive material and the binder was 2 wt% and 1 wt%, respectively, based on the weight of the positive electrode composite.

[0292] (Cathode manufacturing)

[0293] A copper foil was prepared as the cathode current collector, and a conductive polymer solution containing PEDOT(Poly(3,4-ethylenedioxythiophene))-TMA was prepared. The conductive polymer solution was prepared by mixing 0.5 wt% of PEDOT(Poly(3,4-ethylenedioxythiophene))-TMA and 99.5 wt% of a solvent based on the weight of the solution. Nitromethane was used as the solvent. The conductive polymer contained in the solution was prepared to include p-toluenesulfonate as an anionic dopant. Subsequently, an electrodeposition-inducing layer was formed by spray coating the conductive polymer solution onto the cathode current collector using an airbrush connected to Ar gas. The diameter of the spray nozzle of the airbrush used for spray coating was 0.2 mm. The thickness of the electrodeposition-inducing layer formed after the solvent evaporated following spray coating was set to 2 μm. Subsequently, the cathode current collector with the electrodeposition-inducing layer was immersed in a 1 mM aqueous solution of silver nitrate (AgNO3) for 10 minutes to form silver particles on the polymer surface.

[0294] (Lithium secondary battery manufacturing)

[0295] A polyolefin-based separator was used.

[0296] A gel polymer electrolyte was used. Fluoroethylene carbonate (FEC) and diethyl carbonate (DEC) were mixed as organic solvents in a 1:2 volume ratio. Subsequently, a liquid electrolyte was prepared by dissolving lithium salts LiDFOB and LiBF4 in the organic solvent at 0.6 M each. Polymer monomer DPHA was dissolved in the liquid electrolyte to achieve a liquid electrolyte : DPHA ratio of 95 : 5 (w:w), and a radical initiator was added to prepare an electrolyte precursor.

[0297] An electrode assembly was prepared by sequentially stacking a cathode, a separator, and an anode, and an electrolyte precursor was injected. Subsequently, a lithium secondary battery was prepared by thermal crosslinking.

[0298]

[0299] Example B-2

[0300] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as in Example B-1, except that the concentration of the silver nitrate (AgNO3) aqueous solution was 20 mM.

[0301]

[0302] Example B-3

[0303] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as Example B-1, except that the time for immersing the negative current collector with the electrodeposition induction layer in an aqueous silver nitrate (AgNO3) solution was 60 minutes.

[0304]

[0305] Example B-4

[0306] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as in Example B-1, except that the conductive polymer was PEDOT-PEG and a perchlorate was used as the anionic dopant.

[0307]

[0308] Example B-5

[0309] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as in Example B-1, except that the conductive polymer was PEDOT-PSS, polystyrene sulfonate was used as the anionic dopant, and the solvent of the conductive polymer solution was H2O.

[0310]

[0311] Example B-6

[0312] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as in Example B-1, except that the conductive polymer was PEDOT, sodium dodecylbenzenesulfonate was used as the anionic dopant, and the solvent of the conductive polymer solution was H2O.

[0313]

[0314] Example B-7

[0315] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as in Example B-1, except that the negative current collector on which the electrodeposition inducing layer is disposed was not immersed in an aqueous silver nitrate (AgNO3) solution and the conductive polymer does not contain an anionic dopant.

[0316]

[0317] Example B-8

[0318] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as Example B-1, except that the negative current collector on which the electrodeposition inducing layer is disposed was not immersed in an aqueous silver nitrate (AgNO3) solution, the conductive polymer did not contain an anionic dopant, and the thickness of the electrodeposition inducing layer was 5 μm.

[0319]

[0320] Example B-9

[0321] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as Example B-1, except that the conductive polymer was PEDOT-PEG, the negative current collector on which the electrodeposition inducing layer was disposed was not immersed in an aqueous silver nitrate (AgNO3) solution, and the conductive polymer did not contain an anionic dopant.

[0322]

[0323] Example B-10

[0324] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as in Example B-1, except that the conductive polymer was PEDOT-PSS, the negative current collector on which the electrodeposition inducing layer was disposed was not immersed in an aqueous silver nitrate (AgNO3) solution, the conductive polymer did not contain an anionic dopant, and the solvent of the conductive polymer solution was H2O.

[0325]

[0326] Example B-11

[0327] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as in Example B-1, except that the conductive polymer was PEDOT, the negative current collector on which the electrodeposition inducing layer was disposed was not immersed in an aqueous silver nitrate (AgNO3) solution, the conductive polymer did not contain an anionic dopant, and the solvent of the conductive polymer solution was H2O.

[0328]

[0329] Comparative Example B-1

[0330] As indicated in Table 3, a lithium secondary battery was prepared in the same manner as Example B-1, except that an electrodeposition-inducing layer was not formed on the negative current collector and the negative current collector was not immersed in an aqueous silver nitrate (AgNO3) solution.

[0331]

[0332] Classification Conductive Polymer Electroplating Inducing Layer Thickness (μm) Silver Nitrate Aqueous Solution Concentration (mM) Immersion Time (min) Anion Pant Solvent of Polymer Solution Example B-1 PEDOT-TMA2 110 p-toluenesulfonate nitromethane Example B-2 PEDOT-TMA2 20 10 p-toluenesulfonate nitromethane Example B-3 PEDOT-TMA2 16 0 p-toluenesulfonate nitromethane Example B-4 PEDOT-PEG2 110 perchlorate nitromethane Example B-5 PEDOT-PSS2 110 polystyrene sulfonate H2O Example B-6 PEDOT2 110 dodecylbenzenesulfonate sodium H2O Example B-7 PEDOT-TMA2 nitromethane Example B-8 PEDOT-TMA5 nitromethane Example B-9 PEDOT-PEG2---Nitromethane Example B-10 PEDOT-PSS2---H2O Example B-11 PEDOT2---H2O Comparative Example B-1------

[0333] Evaluation Example B-1: Measurement of Dose Retention Rate (%, @100cy)

[0334] For the lithium secondary battery prepared according to the examples and comparative examples, constant current charging was performed at 45°C at a current rate of 0.1C until the voltage reached 4.5V (vs. Li), and then cut-off was performed at a current rate of 0.05C while maintaining 4.5V in constant voltage mode. Subsequently, during discharge, the battery was discharged at a constant current rate of 0.1C until the voltage reached 2.8V (vs. Li) (formation stage, 1st cycle).

[0335] The formation process was completed by performing this charge-discharge process once.

[0336] A lithium secondary battery that has undergone the formation stage was charged at 45°C with a constant current of 0.33C in a voltage range of 2.8 to 4.5 V relative to lithium metal, and then cut off at a current rate of 0.05C while maintaining 4.5V in constant voltage mode. Subsequently, constant current discharge was performed at 1.0C until a cut-off voltage of 2.8V was reached. The aforementioned charge-discharge process was repeated a total of 100 times. In all charge-discharge cycles, a 5-minute pause was observed after each charge / discharge cycle. Here, the capacity retention rate in the Nth cycle is defined by the following Equation B-1.

[0337]

[0338] [Equation B-1]

[0339] Capacity Retention Rate (%) = (Discharge Capacity at Nth Cycle / Discharge Capacity at 1st Cycle) × 100

[0340]

[0341] The capacity retention rate at the 100th cycle for each is listed in Table 4.

[0342]

[0343] Evaluation Example B-2: SEM

[0344] After performing an initial charge on the lithium secondary battery prepared according to the example and comparative example, the surface of the negative electrode was photographed with an SEM and is shown in FIGS. 12a to 12c.

[0345]

[0346] Evaluation Example B-3: Analysis of the amount of active lithium

[0347] A negative electrode was obtained after the formation process for the lithium secondary batteries prepared according to the examples and comparative examples. A cell was constructed using the obtained negative electrode, copper foil as the counter electrode, and a separator to prevent a short circuit between the two electrodes. The fabricated cell achieved 1.0 mA / cm²2 The amount of active lithium was analyzed using the voltage profile measured while discharging at a current density, and the results are shown in Fig. 13.

[0348]

[0349] Evaluation Example B-4: Measurement of nucleation over-potential

[0350] A cell was constructed using the negative electrode of a lithium secondary battery prepared according to the examples and comparative examples, using Li metal as the counter electrode, and adding a separator to prevent a short circuit between the two electrodes. Subsequently, 1.0 mA / cm² 2 Li was electrodeposited on the cathode at a current density, and the lithium nucleation over-potential was analyzed using the voltage profile measured at that time, and the results are shown in Fig. 14.

[0351]

[0352] Classification Capacity Retention Rate (%, @100cy) Example B-18 4.7 Example B-28 1.0 Example B-37 7.3 Example B-47 5.0 Example B-57 2.5 Example B-67 1.2 Example B-78 0.4 Example B-87 8.9 Example B-97 3.8 Example B-107 0.6 Example B-116 9.5 Comparative Example B-16 4.9

[0353] Referring to Table 4, it can be seen that when an electrodeposition inducing layer containing a conductive polymer having PEDOT is placed on a negative current collector, it has a higher capacity retention rate than a comparative example in which no electrodeposition inducing layer is placed.

[0354] Referring to FIGS. 12a to 12c, when an electrodeposition-inducing layer comprising a conductive polymer having PEDOT is disposed on a negative electrode current collector, it can be seen that lithium is electrodeposited more uniformly on the negative electrode than in a comparative example where no electrodeposition-inducing layer is disposed.

[0355] Referring to FIG. 13, it can be seen that when an electrodeposition inducing layer containing a conductive polymer having PEDOT is placed on a negative current collector, the amount of active lithium increases compared to a comparative example in which no electrodeposition inducing layer is placed.

[0356] Referring to Fig. 14, it can be seen that when the conductive polymer included in the electrodeposition induction layer further includes silver particles, it has a smaller nucleation over-potential than the comparative example that does not include silver particles.

[0357] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto and can be implemented with various modifications within the scope of the claims, the detailed description of the invention, and the attached drawings, and it is obvious that such modifications also fall within the scope of the present invention.

Claims

1. Cathode current collector; and The electrodeposition inducing layer disposed on the above-mentioned cathode current collector and comprising metal particles and a conductive polymer, and The above conductive polymer is a negative electrode for a lithium secondary battery comprising PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate).

2. In Paragraph 1, The above metal particles are a negative electrode for a lithium secondary battery comprising a lithium-affinity metal.

3. In Paragraph 2, The above lithium-affinity metal comprises silver (Ag), magnesium (Mg), zinc (Zn), aluminum (Al), tin (Sn), or a combination thereof, for a negative electrode for a lithium secondary battery.

4. In Paragraph 1, The above conductive polymer includes an anion dopant, and The above-mentioned anionic dopant comprises perchlorate, sulfate, p-toluenesulfonate, polystyrene sulfonate, sodium dodecyl benzene sulfonate, or a combination thereof, for a negative electrode for a lithium secondary battery.

5. In Paragraph 1, A negative electrode for a lithium secondary battery, wherein the thickness of the electrodeposition inducing layer is 0.1 μm or more and 10 μm or less.

6. Anode; Negative electrode for a lithium secondary battery; and Electrolyte disposed between the anode and the cathode for the lithium secondary battery Includes, The negative electrode for the above lithium secondary battery is, cathode current collector; and An electrodeposition-inducing layer disposed on the above-mentioned cathode current collector and comprising metal particles and a conductive polymer Includes, The above conductive polymer comprises PEDOT-TMA (Poly(3,4-ethylenedioxythiophene)-tetramethacrylate), a lithium secondary battery.

7. In Paragraph 6, A lithium secondary battery in which a negative active material layer is absent (free) on the negative current collector before charging.

8. In Paragraph 6, The above electrolyte comprises a carbonate-based organic solvent and a lithium salt, and A lithium secondary battery comprising the above-mentioned carbonate-based organic solvent, fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methyl ethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), or a combination thereof.

9. In Paragraph 8, A lithium secondary battery, wherein the above electrolyte further comprises a crosslinking agent for forming a polymer matrix.

10. In Paragraph 9, A lithium secondary battery in which at least a portion of the conductive polymer is cross-linked with at least a portion of the cross-linking agent.

11. An anode comprising an anode current collector and an anode composite portion disposed on the anode current collector; A cathode comprising a cathode current collector and an electrodeposition inducing layer disposed on the cathode current collector; and It includes an electrolyte disposed between the anode and the cathode, and The above-mentioned anode composite part includes an anode active material and a sacrificial anode active material, and A lithium secondary battery comprising a conductive polymer having PEDOT (Poly(3,4-ethylenedioxythiophene)) in the electrodeposition-inducing layer.

12. In Paragraph 11, A lithium secondary battery comprising the conductive polymer, wherein the conductive polymer comprises PEDOT(Poly(3,4-ethylenedioxythiophene)), PEDOT-TMA(Poly(3,4-ethylenedioxythiophene)-tetramethacrylate), PEDOT-PSS(Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate), PEDOT-PEG(poly(3,4-ethylenedioxythiophene)-co-poly(ethylene glycol)), or a combination thereof.

13. In Paragraph 11, The above conductive polymer includes an anion dopant, and A lithium secondary battery comprising the above-mentioned anion dopant, perchlorate, sulfate, p-toluenesulfonate, polystyrene sulfonate, sodium dodecyl benzene sulfonate, or a combination thereof.

14. In Paragraph 11, A lithium secondary battery in which the electrodeposition-inducing layer further comprises metal particles.

15. In Paragraph 11, A lithium secondary battery having a thickness of the electrodeposition inducing layer of 0.1 μm or more and 10 μm or less.

16. In Paragraph 11, The above sacrificial cathode active material comprises Li5FeO4, Li2MoO3, Li6CoO4, Li2O, Li3N, Li3P, or a combination thereof, in a lithium secondary battery.

17. In Paragraph 11, A lithium secondary battery in which the capacity ratio between the positive active material and the sacrificial positive active material is 1:1 to 9:

1.

18. In Paragraph 11, A lithium secondary battery in which a negative active material layer is absent (free) on the negative current collector before charging.

19. In Paragraph 11, The above electrolyte comprises a carbonate-based organic solvent and a lithium salt, and A lithium secondary battery comprising the above-mentioned carbonate-based organic solvent, fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methyl ethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), or a combination thereof.

20. In Paragraph 19, A lithium secondary battery, wherein the above electrolyte further comprises a crosslinking agent for forming a polymer matrix.

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