Electrode current collector, method for manufacturing same, and lithium battery comprising same

Abstract

The present invention provides an electrode current collector, a method for manufacturing same, and a lithium battery comprising same. The electrode current collector includes: a metal substrate; and a metal oxide layer disposed on at least one surface of the metal substrate, wherein the metal substrate includes titanium (Ti), and the metal oxide layer includes crystalline titanium oxide (TiO2).

Description

Electrode current collector, method for manufacturing same, and lithium battery including same

[0001] An electrode current collector including a specific metal, a method for manufacturing the same, and a lithium battery including the same are provided.

[0002] Lithium secondary batteries are high-performance secondary batteries with the highest energy density among the currently commercialized secondary batteries and can be used in various fields such as electric vehicles.

[0003] Copper metal is used as the negative electrode collector in lithium batteries. When copper is used as the negative electrode collector, copper oxides formed on the surface of the copper metal can cause dendrites to form on the negative electrode collector, reducing the lifespan and stability of the lithium battery. Therefore, improvements are needed to address this issue.

[0004] One aspect is to provide an electrode current collector comprising a specific metal and a specific metal oxide.

[0005] Another aspect is to provide a method for manufacturing the above-described electrode collector.

[0006] Another aspect is to provide a lithium battery comprising the electrode current collector described above.

[0007] metal substrate; and

[0008] Comprising a metal oxide layer disposed on at least one surface of the metal substrate,

[0009] The above metal substrate includes titanium (Ti),

[0010] An electrode current collector is provided, wherein the metal oxide layer comprises crystalline titanium oxide (TiO2).

[0011] According to another aspect, the step of preparing a metal substrate;

[0012] A step of heat-treating the metal substrate to form a metal oxide layer on at least one surface of the metal substrate is included.

[0013] The above metal substrate includes titanium (Ti),

[0014] A method for manufacturing an electrode current collector is provided, wherein the metal oxide layer includes crystalline titanium oxide (TiO2).

[0015] According to another aspect, a lithium battery including the electrode current collector described above is provided.

[0016] According to an embodiment, the electrode current collector includes titanium (Ti) and crystalline titanium oxide (TiO2) formed on the surface of the current collector, so that the lithium electrodeposition shape can be improved. In particular, the crystalline titanium oxide (TiO2) formed thinly on the surface can be improved even if it undergoes only a small amount of lithium intercalation reaction (Li x Since TiO2) exhibits electrical conductivity, it exhibits electrical conductivity across the entire surface area of ​​the titanium collector, which enables lithium deposition across the entire surface area of ​​the titanium collector.

[0017] Accordingly, lithium metal can be formed more uniformly on a titanium electrode current collector including crystalline titanium oxide on the surface. In addition, a lithium battery including the electrode current collector can suppress initial dendrite formation.

[0018] Figure 1 is a cross-sectional schematic diagram of an electrode current collector according to an embodiment.

[0019] Figure 2 is a cross-sectional schematic diagram of a lithium battery according to an embodiment.

[0020] Figure 3 is a cross-sectional schematic diagram of a lithium battery according to an embodiment.

[0021] Figure 4 is a schematic diagram of a lithium battery according to an exemplary embodiment.

[0022] Figure 5 is a schematic diagram of a lithium battery according to an exemplary embodiment.

[0023] Figure 6 is a schematic diagram of a lithium battery according to an exemplary embodiment.

[0024] Hereinafter, an electrode current collector (100), a method for manufacturing the same, and a lithium battery (10) including the same, which includes a metal substrate (110) according to one embodiment; and a metal oxide layer (120) disposed on at least one surface of the metal substrate (110), wherein the metal substrate (110) includes titanium (Ti) and the metal oxide layer (120) includes crystalline titanium oxide (TiO2), will be described in more detail. These examples are merely presented as examples to more specifically explain the present invention, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of conflict, the present specification, including its definitions, shall prevail.

[0026] Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein. The singular expression "singular" includes plural expression unless the context clearly indicates otherwise.

[0027] In this specification, the terms "include" or "have" are intended to indicate the presence of a feature, number, step, operation, component, part, ingredient, material or combination thereof described in the specification, but should be understood to not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, ingredients, materials or combinations thereof.

[0028] The term "combination of these" in this specification means a mixture or combination of one or more of the described components.

[0029] As used herein, the term "and / or" is meant to include any and all combinations of one or more of the items described herein. As used herein, the term "or" means "and / or." The expressions "at least one," "one or more," or "one or more" preceding elements herein may supplement the entire list of elements and do not mean that they supplement individual elements described above.

[0030] In order to clearly represent various layers and regions in the drawings, the thicknesses are enlarged or reduced. The same drawing reference numerals are used for similar parts throughout the specification. When a layer, film, region, plate, etc. is referred to as being "on" or "above" another part throughout the specification, this includes not only cases where it is directly above the other part, but also cases where there is another part in between. The terms first, second, etc. may be used throughout the specification to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another.

[0031] In this disclosure, “metal” includes both metals and metalloids such as silicon and germanium, in their elemental or ionic states.

[0032] In this disclosure, “alloy” means a mixture of two or more metals.

[0033] In the present disclosure, “positive electrode material” means a positive electrode material capable of undergoing lithiation and delithiation.

[0034] In the present disclosure, “negative electrode active material” means a negative electrode material capable of undergoing lithiation and delithiation.

[0035] In the present disclosure, “lithiation” and “lithiating” mean a process of adding lithium to a positive electrode active material or a negative electrode active material.

[0036] In the present disclosure, “delithiation” and “delithiate” mean a process of removing lithium from a positive electrode active material or a negative electrode active material.

[0037] In this disclosure, “charging” and “charging” mean a process of providing electrochemical energy to a battery.

[0038] In this disclosure, “discharging” and “discharging” mean the process of removing electrochemical energy from a battery.

[0039] In the present disclosure, “positive electrode” and “cathode” mean an electrode at which electrochemical reduction and lithiation occur during a discharge process.

[0040] In the present disclosure, “cathode” and “anode” mean electrodes where electrochemical oxidation and delithiation occur during the discharge process.

[0041] With reference to the attached drawings, exemplary polymer electrolytes and lithium batteries including the same will be described in more detail below.

[0042] [Electrode collector]

[0043] Figure 1 shows a cross-sectional schematic diagram of an electrode collector (100) according to an embodiment.

[0044] Referring to FIG. 1, the electrode current collector (100) includes a metal substrate (110); and a metal oxide layer (120) disposed on at least one surface of the metal substrate (110). The metal substrate (110) includes titanium (Ti), and the metal oxide layer (120) may include crystalline titanium oxide (TiO2). In this case, the crystalline titanium oxide (TiO2) included in the metal oxide layer (120) undergoes a very small amount of lithium intercalation reaction at the beginning of the lithium battery charge (Li xSince the electrical conductivity of the TiO2 layer is excellent, lithium metal can be uniformly deposited on the electrode current collector (100). For example, when the metal oxide layer (120) includes crystalline titanium oxide (TiO2), the crystalline titanium oxide undergoes a very small amount of lithium intercalation reaction at the beginning of the lithium battery charge (Li x Since the electrical conductivity of TiO2 is excellent, lithium metal can be deposited even on the surface of crystalline titanium oxide. Accordingly, when the metal oxide layer (120) includes crystalline titanium oxide, lithium metal can be uniformly deposited on the entire surface of the electrode current collector (100), so that initial dendrite formation can be effectively suppressed.

[0045] On the other hand, when the metal oxide layer (120) includes an oxide having low electrical conductivity rather than crystalline titanium oxide, lithium metal may not be deposited on the surface of the oxide having low electrical conductivity. For example, a copper (Cu) current collector used as a commercial negative electrode current collector is mainly composed of copper oxide (CuO) or copper hydroxide (Cu(OH)2) as a surface component, which is an insulator, and even if a lithium insertion reaction is performed, insulator lithium oxide (Li2O) or lithium hydroxide (LiOH) is generated, which deteriorates the surface electrical conductivity. Therefore, when lithium is deposited on the surface of the copper current collector, lithium deposition is possible only in a local area, avoiding the area where the oxide or hydroxide exists, and lithium dendrites may be generated.

[0046] According to one embodiment, the metal oxide layer (120) may be binder-free. For example, the metal oxide layer (120) may be formed on at least one surface of the metal substrate (110) by heat-treating the metal substrate (110). For example, since the metal oxide layer (120) does not include a binder, the electrical conductivity of the metal oxide layer (120) may be improved. Accordingly, lithium metal may be more uniformly deposited on the metal oxide layer (120).

[0047] According to one embodiment, the metal oxide layer (120) may be free of copper oxide (CuO). For example, unlike titanium oxide (TiO2), copper oxide (CuO) has no electrical conductivity, so lithium metal is not deposited on the surface of copper oxide (CuO). Therefore, when the metal oxide layer (120) includes copper oxide (CuO), lithium metal may not be uniformly deposited on the surface of the metal oxide layer (120). On the other hand, since the metal oxide layer (120) of the present invention does not include copper oxide (CuO), lithium metal may be uniformly deposited on the electrode current collector (100).

[0048] According to one embodiment, the thickness of the metal oxide layer (120) may be 1 to 600 nm. According to one embodiment, the thickness of the metal oxide layer (120) may be 1 to 550 nm, 1 to 500 nm, 50 to 600 nm, 100 to 600 nm, 200 to 600 nm, 300 to 600 nm, 400 to 600 nm, or 400 to 500 nm.

[0049] According to one embodiment, the crystalline titanium oxide (TiO2) may include an anatase structure or a rutile structure.

[0050] According to one embodiment, the metal oxide layer (120) can completely cover the surface of the metal substrate (110).

[0051] According to one embodiment, the thickness of the metal substrate (110) may be 1 to 50 μm.

[0052] According to one embodiment, the metal substrate (110) includes a base film and a metal layer disposed on one or both sides of the base film, and the metal layer may include titanium (Ti).

[0053] According to one embodiment, the base film includes a metal or a polymer, and the metal in the base film includes indium (In), copper (Cu), magnesium (Mg), titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li) or an alloy thereof, and the polymer in the base film may include polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), polyimide (PI) or a combination thereof.

[0054] For example, when the base film includes 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. Since the base film includes a thermoplastic polymer, the base film may melt when a short circuit occurs, thereby suppressing a rapid increase in current. The base film may be, for example, an insulator.

[0055] For example, when the base film includes a metal, the metal may include indium (In), copper (Cu), magnesium (Mg), titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof.

[0056] For example, as the thickness of the metal layer decreases, the limit current and / or maximum current of the electrode current collector (100) decreases, so the stability of the lithium battery during a short circuit can be improved.

[0057] According to one embodiment, a lead tab may be added to the electrode current collector (100) for external connection. The lead tab may be welded to the electrode current collector (100) by ultrasonic welding, laser welding, spot welding, or the like. During welding, the base film and / or the metal layer may be melted, so that the metal layer may be electrically connected to the lead tab. To make the welding of the metal layer and the lead tab more secure, a metal chip may be added between the metal layer and the lead tab. The metal chip may be a thin piece of the same material as the metal of the metal layer. The metal chip may be, for example, a metal foil, a metal mesh, or the like. The metal chip may be, for example, aluminum foil, copper foil, SUS foil, or the like. By placing the metal chip on the metal layer and then welding it with the lead tab, the lead tab may be welded to a metal chip / metal layer laminate or a metal chip / metal layer / base film laminate. During welding, the base film, metal layer, and / or metal piece may be melted, electrically connecting the metal layer or the metal layer / metal piece laminate to the lead tab. A metal chip and / or lead tab may be added to a portion of the metal layer.

[0058] For example, the thickness of the base film can be, for example, 1 to 50 ㎛, 1.5 to 50 ㎛, 1.5 to 40 ㎛, or 1 to 30 ㎛. When the base film has a thickness in this range, the weight of the electrode assembly can be more effectively reduced. The melting point of the base film can be, for example, 100 to 300 ℃, 100 to 250 ℃ or less, or 100 to 200 ℃. When the base film has a melting point in this range, the base film can be melted during the process of welding the lead tab and easily bonded to the lead tab. In order to improve the adhesion between the base film and the metal layer, a surface treatment such as corona treatment can be performed on the base film. The thickness of the metal layer can be, for example, 0.01 to 3 ㎛, 0.1 to 3 ㎛, 0.1 to 2 ㎛, or 0.1 to ㎛. By having a metal layer with a thickness within this range, conductivity can be maintained while ensuring the stability of the negative electrode. The thickness of the metal piece can be, for example, 2 to 10 μm, 2 to 7 μm, or 4 to 6 μm. By having a metal piece with a thickness within this range, the connection between the metal layer and the lead tab can be performed more easily. By having the electrode current collector (100) with this structure, the weight of the electrode can be reduced, and consequently, the energy density can be improved.

[0059] For example, the electrode current collector (100) may have a form selected from among, for example, a sheet, a foil, a film, a plate, a porous body, a mesoporous body, a body containing through holes, a polygonal ring body, a mesh body, a foam body, and a non-woven body, but is not necessarily limited to these forms, and any form used in the relevant technical field is possible.

[0060] For example, the electrode current collector (100) may have a reduced thickness compared to a conventional electrode current collector. Therefore, the electrode current collector according to the present disclosure is distinguished from a conventional electrode including a thick film current collector by including a thin film current collector. By employing a thin film current collector having a reduced thickness in the electrode current collector according to one embodiment, the thickness of the electrode active material layer or the lithium electrodeposition layer may relatively increase. As a result, the energy density of a lithium battery employing such an electrode current collector (100) may increase. The thickness of the electrode current collector (100) may be, for example, less than 15 um, 14.5 um or less, or 14 um or less. The thickness of the electrode collector (110) may be, for example, 0.1 um to less than 15 um, 1 um to 14.5 um, 2 um to 14 um, 3 um to 14 um, 5 um to 14 um, or 10 um to 14 um.

[0061] [Method for manufacturing electrode collector]

[0062] A method for manufacturing an electrode current collector (100) according to an embodiment of the present invention will be described.

[0063] A method for manufacturing an electrode current collector (100) according to one embodiment includes the steps of preparing a metal substrate (110); and the step of heat-treating the metal substrate (110) to form a metal oxide layer (120) on at least one surface of the metal substrate (110). The metal substrate (110) may include titanium (Ti), and the metal oxide layer (120) may include crystalline titanium oxide (TiO2). For example, titanium (Ti) included in the metal substrate (110) may be oxidized by the heat treatment, so that a metal oxide layer (120) including titanium oxide (TiO2) may be formed on the metal substrate (110).

[0064] According to one embodiment, the heat treatment can be performed inside a kiln.

[0065] According to one embodiment, the heat treatment may include a purging step of injecting oxygen (O2) into the kiln and a temperature raising step of raising the temperature inside the kiln to the maximum temperature.

[0066] According to one embodiment, the maximum temperature may be 200 to 800°C.

[0067] According to one embodiment, the temperature raising step may be performed at a temperature raising rate of 1°C / min to 100°C / min to increase the temperature inside the kiln from room temperature to the maximum temperature.

[0068] According to one embodiment, the heat treatment includes a step of maintaining the temperature inside the kiln at the highest temperature, and the step of maintaining the highest temperature can be performed for 0.1 to 180 minutes.

[0069] [Lithium battery]

[0070] Figures 2 and 3 are cross-sectional schematic diagrams of a lithium battery according to an embodiment.

[0071] Referring to FIGS. 2 and 3, a lithium battery (10) according to one embodiment may include the electrode current collector (100) described above. Since the lithium battery (10) includes the electrode current collector (100) described above, lithium metal is uniformly deposited on the improved electrode current collector (100), thereby preventing lithium dendrite formation.

[0072] The lithium battery (10) may be, for example, a lithium primary battery, a lithium secondary battery, a lithium-sulfur battery, a lithium-air battery, etc., but is not limited thereto, and any lithium battery used in the relevant technical field may be used.

[0073] The lithium battery (10) is manufactured, for example, by the following exemplary method, but is not necessarily limited to this method and is adjusted according to required conditions.

[0074] According to one embodiment, the device comprises: a positive electrode (200); a negative electrode (150); and an electrolyte (300) disposed between the positive electrode (200) and the negative electrode (150), wherein at least one of the positive electrode (200) and the negative electrode (150) may include the electrode current collector (100) described above.

[0075] According to one embodiment, the cathode (150) may include the electrode current collector (100) described above.

[0076] [Cathode current collector]

[0077] According to one embodiment, the electrode current collector (100) may be a negative electrode current collector.

[0078] According to one embodiment, the negative electrode current collector may be free of a negative electrode active material layer prior to charging. For example, the negative electrode current collector may be free of a lithium metal layer prior to charging. For example, in the case of a lithium battery in which the negative electrode current collector is free of a negative electrode active material layer or a lithium metal layer prior to charging and discharging, dendrite formation may be prevented, thereby improving life characteristics.

[0079] In addition, the electrode current collector (100) includes a metal substrate (110) of titanium (Ti) and a metal oxide layer (120) of crystalline titanium oxide (TiO2), so that lithium metal can be uniformly deposited on the negative electrode current collector.

[0080] .[Cathode: Lithium electrodeposition layer]

[0081] According to one embodiment, when the electrode current collector (100) is a negative electrode current collector, a lithium electrodeposition layer (400) may be formed on the negative electrode (150) after charging. For example, a lithium electrodeposition layer (400) may be formed on the electrode current collector (100) after charging. For example, the lithium electrodeposition layer (400) may include lithium metal or a lithium alloy.

[0082] For example, the lithium electrodeposition layer (400) may include a lithium alloy and a lithium metal. For example, the lithium alloy included in the lithium electrodeposition layer (400) may weaken the reactivity of the lithium metal, thereby effectively preventing a side reaction between the lithium electrodeposition layer and the electrolyte described below.

[0083] For example, the lithium alloy may be an alloy of lithium ions and metal ions contained in the metal salt described above, and the metal ions may include the lithium-compatible metal described above. In this case, the lithium alloy may be an alloy of lithium and the lithium-compatible metal. For example, if the lithium-compatible metal is silver (Ag), the lithium alloy may include a Li-Ag alloy.

[0084] [anode]

[0085] For example, the positive electrode (200) may include a positive electrode current collector (210) and a positive electrode active material layer (220) disposed on the positive electrode current collector (210).

[0086] [Anode: Anode current collector]

[0087] For example, the positive electrode (200) includes a positive electrode current collector (210). For example, the positive electrode (200) can be prepared by forming the positive electrode active material layer (220) on the positive electrode current collector (210).

[0088] For example, the positive electrode current collector (210) 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.

[0089] According to one embodiment, the positive electrode collector (210) may include aluminum (Al).

[0090] According to one embodiment, the positive electrode current collector (210) may include, for example, a base film and a metal layer disposed on one or both sides of the base film. 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. Since the base film includes a thermoplastic polymer, the base film may be liquefied when a short circuit occurs, thereby suppressing a rapid increase in current. The base film may be, for example, an insulator. The metal layer 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), or an alloy thereof. The metal layer can act as an electrochemical fuse and be cut off in case of overcurrent to prevent a short circuit. The limit current and the maximum current can be controlled by adjusting the thickness of the metal layer. The metal layer can be plated or deposited on the base film. When the thickness of the metal layer is reduced, the limit current and / or the maximum current of the positive electrode current collector (140) decrease, so that the stability of the lithium battery in case of a short circuit can be improved. A lead tab can be added on the metal layer for connection to the outside. The lead tab can be welded to the metal layer or the metal layer / base film laminate by ultrasonic welding, laser welding, spot welding, etc. During welding, the base film and / or the metal layer melt, so that the metal layer can be electrically connected to the lead tab. In order to make the welding of the metal layer and the lead tab more secure, a metal chip can be added between the metal layer and the lead tab.The metal piece may be a thin piece of the same material as the metal of the metal layer. The metal piece may be, for example, a metal foil, a metal mesh, etc. The metal piece may be, for example, aluminum foil, copper foil, SUS foil, etc. After the metal piece is placed on the metal layer, the lead tab may be welded to the metal piece / metal layer laminate or the metal piece / metal layer / base film laminate. During welding, the base film, the metal layer, and / or the metal piece may melt, so that the metal layer or the metal layer / metal piece laminate may be electrically connected to the lead tab. A metal chip and / or a lead tab may be added to a portion of the metal layer. The base film may have a thickness of, for example, 1 to 50 μm, 1.5 to 50 μm, 1.5 to 40 μm, or 1 to 30 μm. When the base film has a thickness in this range, the weight of the positive electrode current collector can be more effectively reduced. The melting point of the base film may be, for example, 100 to 300°C, 100 to 250°C or less, or 100 to 200°C. Since the base film has a melting point within this range, the base film can be easily combined with the lead tab during the welding process by melting. To improve the adhesion between the base film and the metal layer, a surface treatment such as corona treatment may be performed on the base film. The thickness of the metal layer may be, for example, 0.01 to 3 μm, 0.1 to 3 μm, 0.1 to 2 μm, or 0.1 to 1 μm. Since the metal layer has a thickness within this range, the stability of the electrode assembly can be secured while maintaining conductivity. The thickness of the metal piece may be, for example, 2 to 10 μm, 2 to 7 μm, or 4 to 6 μm. Since the metal piece has a thickness within this range, the connection between the metal layer and the lead tab can be performed more easily. By having this structure, the positive electrode current collector (210) can reduce the weight of the electrode and consequently improve the energy density.

[0091] [Anode: Anode active material layer]

[0092] The above positive electrode active material layer (220) may include a positive electrode active material, a conductive material, and a binder.

[0093] For example, the cathode active material may be at least one of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof, and a specific example thereof is Li a A 1-b B 1 b D 1 2 (in the above formula, 0.90 ≤ a ≤ 1.8, and 0 ≤ b ≤ 0.5); Li a E 1-b B 1 b O 2-c D 1 c (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); LiE 2-b B 1 b O 4-c D 1 c (In the above formula, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); Li a Ni 1-b-c Co b B 1 c D 1 α (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α ≤ 2); Li a Ni 1-b-c Co b B 1 c O 2-α F 1 α (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni 1-b-c Co b B 1c O 2-α F 1 2 (in the above equation, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni 1-b-c Mn b B 1 c D α (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α ≤ 2); Li a Ni 1-b-c Mn b B 1 c O 2-α F 1 α (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni 1-b-c Mn b B 1 c O 2-α F 1 2 (in the above equation, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2); Li a Ni b E c G d O2 (in the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0.001 ≤ d ≤ 0.1); Li a Ni b Co c Mn d GeO2 (in the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, 0.001 ≤ e ≤ 0.1); Li a NiG b O2 (in the above formula, 0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1); Li a CoG bO2 (in the above formula, 0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1); Li a MnG b O2 (in the above formula, 0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1); Li a Mn2G b O4 (in the above formula, 0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1); QO2; QS2; LiQS2; V2O5; LiV2O5; LiIO2; LiNiVO4; Li (3-f) J2(PO4)3(0 ≤ f ≤ 2); Li (3-f) Any compound represented by the chemical formula Fe2(PO4)3(0 ≤ f ≤ 2); LiFePO4 can be used:

[0094] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; B 1 is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, Ga, Si, W, Mo, Cu, Zn, Ti, boron (B), rare earth elements or a combination thereof; D 1 is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F 1 is F, S, P, Cl, Br or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or a combination thereof; Q is Ti, Mo, Mn or a combination thereof; I is Cr, V, Fe, Sc, Y or a combination thereof; J may be V, Cr, Mn, Co, Ni, Cu or a combination thereof.

[0095] For example, the positive electrode active material may include a lithium transition metal oxide containing nickel and another transition metal. In the lithium transition metal oxide containing nickel and another transition metal, the content of nickel may be 60 mol% or more, for example, 75 mol% or more, for example, 80 mol% or more, for example, 85 mol% or more, for example, 90 mol% or more, based on the total mole number of transition metals.

[0096] For example, the lithium transition metal oxide may be a compound represented by the following chemical formula 1:

[0097] <Chemical Formula 1>

[0098] Li a Ni x Co y M z O 2-b A b

[0099] 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,

[0100] A is F, S, Cl, Br or a combination thereof.

[0101] For example, in chemical formula 3, 0.7≤x<1, 0 <y≤0.3, 0<z≤0.3; 0.8≤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.

[0102] For example, the lithium transition metal oxide may be at least one of the compounds represented by the following chemical formulae 1-1 and 1-2:

[0103] <Chemical Formula 1-1>

[0104] LiNi x Co y Mn z O2

[0105] In Chemical Formula 1-1, 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≤0.3이고,

[0106] <Chemical Formula 1-2>

[0107] LiNi x Co y Al z O2

[0108] In Chemical Formula 1-2, 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. 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.

[0109] For example, lithium transition metal oxide is LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.88 Co 0.08 Mn 0.04 O2, LiNi 0.8 Co 0.15 Mn 0.05 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.88 Co 0.1 Mn 0.02 O2, LiNi 0.8 Co 0.15 Al 0.05 O2, LiNi 0.8 Co 0.1 Mn 0.2 O2 or LiNi 0.88 Co 0.1 Al 0.02 It could be O2.

[0110] For example, the above-mentioned positive electrode active material may be used as one having a coating layer on the surface of the lithium transition metal oxide, or may be used by mixing the lithium transition metal oxide and a lithium transition metal oxide having a coating layer.

[0111] For example, the coating layer may include a coating element compound of an oxide, a hydroxide, an oxyhydroxide of the coating element, an oxycarbonate of the coating element, or a hydroxycarbonate of the coating element.

[0112] 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. The coating layer forming process may use any coating method as long as it can coat the lithium transition metal oxide with the coating elements by a method (e.g., spray coating, dipping, etc.) that does not adversely affect the properties of the positive electrode active material. Since this is well understood by those working in the relevant field, a detailed description thereof will be omitted.

[0113] Carbon black, graphite particles, etc. may be used as the above-mentioned conductive material, but are not limited thereto, and any conductive material that can be used in the relevant technical field may be used.

[0114] As the above binder, vinylidene fluoride / hexafluoropropylene copolymer, polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, polytetrafluoroethylene and mixtures thereof, or styrene butadiene rubber polymers may be used, but are not limited thereto, and any binder that can be used in the relevant technical field may be used.

[0115] [Electrolyte]

[0116] According to one embodiment, the lithium battery (10) may include an electrolyte (300) disposed between the positive electrode (200) and the negative electrode (150).

[0117] The electrolyte (300) may be, for example, a liquid electrolyte, a solid electrolyte, a gel electrolyte, or a combination thereof.

[0118] The above electrolyte (300) may be, for example, an organic electrolyte. The organic electrolyte is manufactured, for example, by dissolving a lithium salt in an organic solvent.

[0119] Any organic solvent used in the relevant technical field may be used. Examples of the organic solvent include propylene carbonate, ethylene carbonate, fluoroethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl isopropyl carbonate, dipropyl carbonate, dibutyl carbonate, benzonitrile, acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, γ-butyrolactone, dioxolane, 4-methyldioxolane, N,N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane, 1,2-dimethoxyethane, sulfolane, dichloroethane, chlorobenzene, nitrobenzene, diethylene glycol, dimethyl ether, or mixtures thereof.

[0120] Lithium salts are all possible if they are used as lithium salts in the relevant technical field. Lithium salts include, for example, 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)(1≤x≤20, 1≤y≤20), LiCl, LiI or a mixture thereof. The concentration of the lithium salt is, for example, 0.1 M to 5.0 M.

[0121] The above solid electrolyte is, for example, an oxide-based solid electrolyte, a sulfide-based solid electrolyte, a polymer solid electrolyte, or a combination thereof.

[0122] The above solid electrolyte is, for example, an oxide-based solid electrolyte. The oxide-based solid electrolyte is Li 1+x+y Al x Ti 2-x Si y P 3-y O 12 (0 <x<2, 0혏<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 Si y 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 (M = Te, Nb, or Zr, x is an integer from 1 to 10) is one or more selected from. The solid electrolyte is manufactured by a sintering method, etc. For example, the oxide-based solid electrolyte is Li7La3Zr2O 12 (LLZO) and Li3+x La3Zr 2-a M a O 12 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).

[0123] The sulfide-based solid electrolyte may include, for example, lithium sulfide, silicon sulfide, phosphorus sulfide, boron sulfide, or a combination thereof. The sulfide-based solid electrolyte particles may include Li2S, P2S5, SiS2, GeS2, B2S3, or a combination thereof. The sulfide-based solid electrolyte particles may be Li2S or P2S5. Sulfide-based solid electrolyte particles are known to have high lithium ion conductivity compared to other inorganic compounds. For example, the sulfide-based solid electrolyte includes Li2S and P2S5. When the sulfide solid electrolyte material constituting the sulfide-based solid electrolyte includes Li2S-P2S5, the mixing molar ratio of Li2S to P2S5 may be, for example, in a range of about 50:50 to about 90:10. In addition, Li3PO4, halogen, halogen compound, Li 2+2x Zn 1??x GeO4("LISICON", 0혎<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 S4("ThioLISICON"), Li2O-Al2O3-TiO2-P2O 5(An inorganic solid electrolyte prepared by adding "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-Z m S n (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. 또한, 소성(calcinations) 공정이 상기 처리 후에 수행될 수 있다. 황화물계 고체전해질은 비정질이거나, 결정질이거나, 이들이 혼합된 상태일 수 있다.

[0124] A polymer solid electrolyte is an electrolyte that includes, for example, a mixture of a lithium salt and a polymer, or a polymer having an ion-conducting functional group. A polymer solid electrolyte is, for example, a polymer electrolyte that does not include a liquid electrolyte.Polymers included in the polymer solid electrolyte include, 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), polymethyl methacrylate (PMMA), poly(methylmethacrylate), 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) (SPEEK), sulfonated poly(arylene ether ketone ketone sulfone) (SPAEKKS), sulfonated poly(aryl ether ketone) (SPAEK), poly[bis(benzimidazobenzisoquinolinones)] (SPBIBI), poly(styrene sulfonate) (PSS), lithium 9,10-Diphenylanthracene-2-sulfonate (lithium 9,10-diphenylanthracene-2-sulfonate, DPASLi. +) or a combination thereof, but is not limited thereto, and any polymer electrolyte used in the art may be used. The lithium salt may be any lithium salt that can be used in the art. The lithium salt may be, for example, 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 a mixture thereof.

[0125] A gel electrolyte is, for example, a gel polymer electrolyte. A gel polymer electrolyte is, for example, an electrolyte that includes a liquid electrolyte and a polymer, or an organic solvent and a polymer having an ion-conducting functional group. The liquid electrolyte can 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 can be selected from the polymers used in solid polymer electrolytes. The organic solvent can be selected from the organic solvents used in liquid electrolytes. The lithium salt can be selected from the lithium salts used in solid polymer electrolytes. An ionic liquid refers to a salt that is liquid at room temperature or a room-temperature molten salt that has a melting point below room temperature and is composed only 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 at least one selected from compounds containing at least one anion selected from the group consisting of: a polymer solid electrolyte; a gel polymer electrolyte may be formed by impregnating the polymer solid electrolyte into an electrolyte solution within a lithium battery; and the gel electrolyte may further include inorganic particles.

[0126] [Separator]

[0127] A lithium battery according to an embodiment may further include a separator (not shown).

[0128] Specific examples of the above separator include polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more layers thereof, and mixed multilayer films such as a polyethylene / polypropylene two-layer separator, a polyethylene / polypropylene / polyethylene three-layer separator, and a polypropylene / polyethylene / polypropylene three-layer separator may be used.

[0129] According to one embodiment, the battery case including the lithium battery (10) may be cylindrical, square, thin-film, etc. For example, the lithium battery may be a large-sized thin-film battery. The lithium battery may be a lithium ion battery.

[0130] According to an embodiment, the lithium battery (10) may be, for example, a lithium air battery, a lithium sulfur battery, etc.

[0131] According to one embodiment, the lithium battery (10) can be used in electric vehicles (EVs) due to its excellent lifespan and high-rate characteristics. For example, it can be used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEVs). In addition, it can be used in fields requiring large amounts of power storage. For example, it can be used in electric bicycles, power tools, etc.

[0132] When stacking multiple lithium batteries (10) according to an embodiment, a gel-type electrolyte may be placed between the positive electrode and the liquid-impermeable ion-conductive composite membrane. The gel-type electrolyte may include, for example, a VDF-HFP copolymer, a lithium salt, and a solvent.

[0133] Referring to FIG. 4, a lithium battery (1) according to one embodiment includes a positive electrode (3), the above-described negative electrode (2), and a separator (4). 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 accommodated in a battery case (5). A polymer electrolyte is injected into the battery case (5) and sealed with a cap assembly (6), thereby completing the lithium battery (1). The battery case (5) is cylindrical, but is not necessarily limited to this shape, and may be, for example, square, thin-film, etc.

[0134] For example, a polymer electrolyte including a positive electrode (3), a negative electrode (2), and a separator (4) is wound or folded to form a battery structure (7). The formed battery structure (7) is accommodated in a battery case (5). A liquid electrolyte is injected into the battery case (5) and sealed with a cap assembly (6), thereby completing a lithium battery (1). The battery case (5) is cylindrical, but is not necessarily limited to this shape, and may be, for example, square, thin-film, etc.

[0135] Referring to FIG. 5, a lithium battery (1) according to one embodiment includes a positive electrode (3), the above-described 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 accommodated in a battery case (5). An electrode tab (8) that serves as an electrical path for guiding a current formed in the battery structure (7) to the outside may be included. The above-described polymer electrolyte is injected into the battery case (5) and sealed to complete the lithium battery (1).

[0136] For example, after a polymer electrolyte including a separator (4) is placed between a positive electrode (3) and a negative electrode (2), 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 accommodated in a battery case (5). An electrode tab (8) that serves as an electrical path for guiding the current formed in the battery structure (7) to the outside may be included. A liquid electrolyte may be injected into the battery case (5) and sealed to complete the lithium battery (1). The battery case (5) is not necessarily limited to a square shape, but may be, for example, a cylindrical shape, a thin film shape, etc.

[0137] Referring to FIG. 6, a lithium battery (1) according to an embodiment includes a positive electrode (3), the above-described negative electrode (2), and a separator (4). The above-described polymer electrolyte including the separator (4) is disposed between the positive electrode (3) and the negative electrode (2), thereby forming a battery structure. The battery structure (7) is stacked in a bi-cell structure and then accommodated in a battery case (5). An electrode tab (8) serving as an electrical path for guiding the current formed in the battery structure (7) to the outside may be included. A liquid electrolyte is injected into the battery case (5) and sealed, thereby completing the lithium battery (1). The battery case (5) is not necessarily limited to a square shape, but may be, for example, a cylindrical shape, a thin-film shape, etc.

[0138] A pouch-type lithium battery corresponds to the lithium batteries of FIGS. 4 to 6, each of which uses a pouch as a battery case. The pouch-type lithium battery includes one or more battery structures. A polymer electrolyte is disposed between a positive electrode and a negative electrode to form a battery structure. The battery structures are laminated in a bi-cell structure, then impregnated with a liquid electrolyte, and accommodated and sealed in a pouch to complete the pouch-type lithium battery. For example, although not shown in the drawings, a polymer electrolyte including the above-described positive electrode, negative electrode, and separator may be simply laminated and accommodated in a pouch in the form of an electrode assembly, or may be wound or folded into a jelly-roll-shaped electrode assembly and then accommodated in a pouch. Subsequently, a liquid electrolyte is injected into the pouch and sealed to complete the lithium battery.

[0139] Lithium batteries are used in electric vehicles (EVs) due to their excellent cycle life and high-rate characteristics. For example, they are used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEVs). They are also used in applications requiring large amounts of power storage, such as electric bicycles and power tools.

[0140] Lithium batteries are stacked in multiple layers to form a battery module, and the multiple 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. The battery module includes, for example, multiple batteries and a frame that holds them. The battery pack includes, for example, multiple battery modules and a bus bar that connects them. The battery module and / or the battery pack may further include a cooling device. The multiple 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.

[0141] The following examples and comparative examples are provided for further details. However, the examples are provided for illustrative purposes only and are not intended to be limiting.

[0142] Manufacturing Example 1: Manufacturing of electrode current collector

[0143] A 10 μm thick titanium metal foil was prepared as a metal substrate. The titanium metal was heated to a maximum temperature of 500°C at a heating rate of 5°C per minute in an oxygen 100% atmosphere, and then heat-treated while maintaining it at 500°C for 2 hours to form a metal oxide layer containing rutile titanium oxide on the titanium metal surface, thereby manufacturing an electrode current collector. The metal oxide layer had a thickness of 400 nm to 500 nm.

[0144] Manufacturing Example 2: Manufacturing of electrode current collector

[0145] A 10 μm thick titanium metal foil was prepared as a metal substrate. The titanium metal was heated to a maximum temperature of 600°C at a heating rate of 5°C per minute in an oxygen 100% atmosphere, and then heat-treated while maintaining it at 600°C for 2 hours to form a metal oxide layer containing rutile titanium oxide on the titanium metal surface, thereby manufacturing an electrode current collector. The metal oxide layer had a thickness of 400 nm to 500 nm.

[0146] Manufacturing Example 3: Manufacturing of electrode current collector

[0147] A 10 μm thick titanium metal foil was prepared as a metal substrate. The titanium metal was heated to a maximum temperature of 250°C at a heating rate of 5°C per minute in an oxygen 100% atmosphere, and then heat-treated at 250°C for 2 hours to form a metal oxide layer containing anatase titanium oxide on the titanium metal surface, thereby manufacturing an electrode current collector. The metal oxide layer had a thickness of 400 nm to 500 nm.

[0148] Comparative Manufacturing Example 1: Manufacturing of Electrode Current Collector

[0149] A 10 μm thick copper metal foil was prepared using a metal substrate. XPS analysis confirmed that a natural oxide layer containing CuO or Cu(OH)2 existed on the surface of the copper foil product without additional heat treatment.

[0150] Comparative Manufacturing Example 2: Manufacturing of an Electrode Current Collector

[0151] A 10 μm-thick titanium metal foil was prepared using a metal substrate. XPS analysis confirmed that an oxide layer containing amorphous TiO2 naturally existed on the surface of the titanium foil product without additional heat treatment.

[0152] Comparative Manufacturing Example 3: Manufacturing of an Electrode Current Collector

[0153] A 12 μm thick aluminum metal foil was prepared as a metal substrate. XPS analysis confirmed that a natural oxide layer containing Al2O3 existed on the surface of the aluminum foil product without additional heat treatment.

[0154] Metal oxide film manufacturing example 1 Titanium metal rutile TiO2 Manufacturing example 2 Titanium metal anatase TiO2 Manufacturing example 3 Titanium coated copper metal rutile TiO2 Comparative manufacturing example 1 Copper metal Cu(OH)2 and CuO Comparative manufacturing example 2 Titanium metal amorphous TiO2 Comparative manufacturing example 3 Aluminum metal Al2O3

[0155] Example 1: Manufacturing of lithium battery (pouch cell)

[0156] LiNi 0.6 Co 0.2 Al 0.2 O2, a conductive agent (Super-P; Timcal Ltd.), a binder (PVDF), and N-methylpyrrolidone were mixed to obtain a cathode composition. LiNi in the cathode composition 0.6 Co 0.2 Al 0.2 The mixing weight ratio of O2, the challenge agent, and the binder was 97.5:1.5:1.

[0157] The above positive electrode composition was coated on top of aluminum foil (thickness: about 15 μm) and dried in a vacuum at about 110°C to manufacture a positive electrode.

[0158] Using the positive electrode manufactured above, a lithium battery (pouch cell) was manufactured using the electrode current collector according to Manufacturing Example 1 as a counter electrode, a polyethylene separator, and a solution containing 1.3 M LiPF6 dissolved in EC (ethylene carbonate) + EMC (ethyl methyl carbonate) + DMC (dimethyl carbonate) (3:4:3 volume ratio) as an electrolyte.

[0159] Examples 2 to 3 and Comparative Examples 1 to 3: Manufacturing of lithium batteries (pouch cells)

[0160] A lithium battery (pouch cell) was manufactured in the same manner as Example 1, except that the type of electrode current collector used was changed as shown in Table 2 below.

[0161] Evaluation Example 1: Charge / Discharge Characteristics

[0162] Lithium batteries (pouch cells) manufactured according to Examples 1 to 3 and Comparative Examples 1 to 3 were charged at a constant current of 0.1 C at 45°C until the voltage reached 4.30 V (vs. Li), and then cut-off was achieved at a current of 0.05 C while maintaining 4.30 V in constant voltage mode. Subsequently, discharge was performed at a constant current of 0.1 C until the voltage reached 3.6 V (vs. Li) (formation stage, 1st cycle). This charge-discharge process was performed once to complete the formation process.

[0163] The lithium battery that had undergone the above-described Mars step was charged at a constant current of 0.33C in a voltage range of 3.6 to 4.3 V vs. lithium metal at 45°C, and then cut-off was performed at a current rate of 0.05C while maintaining 4.30 V in constant voltage mode. Subsequently, constant current discharge was performed at 1.0C until a cut-off voltage of 3.6 V was reached. The above-described charge and discharge process was repeated a total of 100 times.

[0164] In all of the above charge / discharge cycles, a 5-minute pause was allowed after each charge / discharge cycle. Here, the capacity retention rate in the Nth cycle is defined by Equation 1 below.

[0165] [Formula 1]

[0166] Capacity retention rate (%) = [(N th Discharge capacity in cycle / 1 st Discharge capacity in cycle)x100]

[0167] The cycles that reached a capacity retention rate of 80% were measured and are listed in Table 2 below.

[0168] Metal Substrate Charge / Discharge Evaluation Capacity Retention Rate Reaching 80% Cycle Example 1 Manufacturing Example 1176 Example 2 Manufacturing Example 2192 Example 3 Manufacturing Example 3166 Comparative Example 1 Comparative Manufacturing Example 1158 Comparative Example 2 Comparative Manufacturing Example 2148 Comparative Example 3 Comparative Manufacturing Example 343

[0169] Referring to Table 2, Examples 1 to 3, which include electrode structures according to Manufacturing Examples 1 to 3, respectively, showed superior capacity characteristics and capacity retention characteristics compared to Comparative Examples 1 to 3, which include electrode structures according to Comparative Manufacturing Examples 1 to 3, respectively, in which lithium metal was uniformly deposited on the surface of the electrode current collector.

[0170] While the above has been described with reference to drawings and examples, these are merely exemplary, and those skilled in the art will appreciate that various modifications and equivalent other implementations are possible. Accordingly, the scope of protection of the present invention should be defined by the appended claims.

[0171] [Explanation of symbols]

[0172] 10: Lithium battery

[0173] 100: Electrode current collector 110: Metal substrate

[0174] 120: Metal oxide layer 150: Cathode

[0175] 200: Anode 210: Anode current collector

[0176] 220: Cathode active material layer 300: Electrolyte

[0177] 400: Lithium electrodeposition layer

Claims

1. Metal substrate; and Comprising a metal oxide layer disposed on at least one surface of the metal substrate, The above metal substrate includes titanium (Ti), An electrode current collector, wherein the metal oxide layer comprises crystalline titanium oxide (TiO2).

2. In paragraph 1, The above metal oxide layer is a binder-free electrode current collector.

3. In paragraph 1, An electrode current collector in which the metal oxide layer is free of copper hydroxide (Cu(OH)2) and copper oxide (CuO).

4. In paragraph 1, An electrode current collector having a thickness of the metal oxide layer of 1 to 600 nm.

5. In paragraph 1, The above crystalline titanium oxide is an electrode current collector having an anatase structure or a rutile structure.

6. In paragraph 1, An electrode current collector in which the metal oxide layer completely covers the surface of the metal substrate.

7. In paragraph 1, An electrode current collector having a thickness of the metal substrate of 1 to 50 μm.

8. In paragraph 1, The above metal substrate includes a base film and a metal layer disposed on one or both sides of the base film, The above metal layer is an electrode current collector comprising titanium (Ti).

9. In paragraph 7, The above base film comprises a metal or polymer, Among the above base films, the metal includes indium (In), copper (Cu), magnesium (Mg), titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li) or an alloy thereof. An electrode current collector, wherein the polymer among the base films comprises polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), polyimide (PI), or a combination thereof.

10. Step of preparing metal substrate; A step of heat-treating the metal substrate to form a metal oxide layer on at least one surface of the metal substrate, The above metal substrate includes titanium (Ti), A method for manufacturing an electrode current collector, wherein the metal oxide layer comprises crystalline titanium oxide (TiO2).

11. In paragraph 10, The above heat treatment is performed inside the kiln, The above heat treatment includes a purging step of injecting oxygen (O2) into the furnace; and A method for manufacturing an electrode current collector, comprising a heating step of raising the temperature inside the above-mentioned sintering furnace to the highest temperature.

12. In paragraph 11, A method for manufacturing an electrode current collector, wherein the highest temperature is 200 to 800°C.

13. In paragraph 11, A method for manufacturing an electrode current collector, wherein the above-described temperature raising step is performed at a temperature raising rate of 1°C / min to 100°C / min from room temperature to the maximum temperature inside the kiln.

14. In paragraph 11, The above heat treatment includes a step of maintaining the temperature inside the kiln at the highest temperature, A method for manufacturing an electrode current collector, wherein the step of maintaining the highest temperature is performed for 0.1 to 180 minutes.

15. Anode; cathode; and It includes an electrolyte disposed between the positive and negative electrodes, A lithium battery, wherein at least one of the positive and negative electrodes comprises an electrode current collector according to claim 1.

16. In paragraph 15, A lithium battery, wherein the negative electrode includes the electrode current collector.

17. In paragraph 16, A lithium battery in which the negative electrode is free of a negative electrode active material layer before charging.

18. In paragraph 16, A lithium battery further comprising a lithium electrodeposition layer disposed on the negative electrode after charging.

19. In paragraph 15, A lithium battery, wherein the electrolyte comprises a liquid electrolyte, a solid electrolyte, a gel electrolyte, or a combination thereof.

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