Electrode for rechargeable lithium battery and rechargeable lithium battery including the same

Abstract

An electrode and a rechargeable lithium battery including the same are provided. The electrode includes a current collector and a multi-active material layer on the current collector. The multi-active material layer includes: a first electrode mixture layer on the current collector; a second electrode mixture layer on the first electrode mixture layer; and a third electrode mixture layer on the second electrode mixture layer. Each of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer includes an electrode active material and a binder. The first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer have different bonding doses. A first thickness of the first electrode mixture layer is less than a second thickness of the second electrode mixture layer. The first thickness is less than a third thickness of the third electrode mixture layer.

Description

[0001] This application claims the priority and benefit of Korean Patent Application No. 10-2024-0002659, filed with the Korean Intellectual Property Office on January 8, 2024, the entire content of which is incorporated herein by reference. Technical Field

[0002] According to one or more embodiments, the present disclosure relates to an electrode for a rechargeable lithium battery and a rechargeable lithium battery including the electrode. Background Art

[0003] Recently, with the rapid spread of electronic devices using batteries (such as mobile phones, laptop computers, electric vehicles, etc.), the expectation or demand for rechargeable batteries having a relatively high energy density and a relatively high capacity has increased rapidly. Accordingly, in-depth research has been conducted to improve the performance of rechargeable lithium batteries.

[0004] A rechargeable lithium battery includes a positive electrode, a negative electrode, and an electrolyte, and the positive electrode and the negative electrode include active materials in which insertion and extraction (e.g., of lithium ions) are possible. For example, if (e.g., when) lithium ions are inserted and / or extracted, the rechargeable lithium battery generates electrical energy caused by oxidation and reduction reactions. Summary of the Invention

[0005] One or more aspects relate to an electrode for a rechargeable lithium battery that can exhibit high stability while performing fast charging.

[0006] One or more aspects relate to a rechargeable lithium battery including the electrode.

[0007] Additional aspects will be set forth in part in the description below, and in part will be obvious from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0008] According to one or more embodiments of the present disclosure, an electrode for a rechargeable lithium battery may include: a current collector; and a multi-active material layer on the current collector. The multi-active material layer may include: a first electrode mixture layer on the current collector; a second electrode mixture layer on the first electrode mixture layer; and a third electrode mixture layer on the second electrode mixture layer. Each of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer may include an electrode active material and a binder. The first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer may each independently have a binder amount, and the binder amounts are each different binder amounts. A first thickness of the first electrode mixture layer may be less than a second thickness of the second electrode mixture layer. The first thickness may be less than a third thickness of the third electrode mixture layer.

[0009] According to one or more embodiments of the present disclosure, an electrode for a rechargeable lithium battery may include: a current collector; and a multi-active material layer on the current collector. The multi-active material layer may include: a first electrode mixture layer on the current collector; a second electrode mixture layer on the first electrode mixture layer; and a third electrode mixture layer on the second electrode mixture layer. Each of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer may include an electrode active material and a binder. The difference in the binder ratio between the first electrode mixture layer and the second electrode mixture layer may be in the range of about 0.1 to about 0.6. The difference in the binder ratio between the second electrode mixture layer and the third electrode mixture layer may be in the range of about 0 to about 0.4. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A simplified conceptual diagram of a rechargeable lithium battery according to one or more embodiments of the present disclosure is shown.

[0011] Figures 2 to 5 Each shows a simplified cross-sectional view of a rechargeable lithium battery according to one or more embodiments of the present disclosure.

[0012] Figure 6 A cross-sectional view of an electrode for a rechargeable lithium battery according to one or more embodiments of the present disclosure is shown.

[0013] Figure 7 A graph showing the distribution of the binder in the multi-layer electrode according to Embodiments 1 to 3 of the present disclosure is shown.

[0014] Figure 8 A graph showing the distribution of the binder in the multi-layer electrode of Comparative Examples 1 to 4 is shown.

[0015] Figure 9 A graph showing the evaluation results of the adhesion strength between the current collector and the active material layer in the electrodes of Embodiments 1 to 3 of the present disclosure and Comparative Examples 1 to 4 is shown. DETAILED DESCRIPTION

[0016] Hereinafter, specific embodiments will be described in more detail so that those of ordinary skill in the art can easily implement them and fully understand the structure and aspects of the present disclosure. Examples of specific embodiments are shown in the accompanying drawings, in which the same reference numerals always refer to the same elements, and their repeated description may not be provided. Accordingly, one or more embodiments will be described with reference to the accompanying drawings to explain the aspects of the present specification. However, it should be noted that the present disclosure is not limited to the following exemplary embodiments, but may be implemented in one or more suitable forms. On the contrary, the exemplary embodiments are provided only to enable those skilled in the art to fully understand the scope of the present disclosure.

[0017] Here, it should be understood that terms such as "comprising", "including", "having" and / or their variants are intended to indicate the presence of the embodied aspects, quantities, steps (e.g., actions or tasks), elements and / or their (e.g., any suitable) combinations, but do not preclude the possibility of the presence or addition of one or more other features, quantities, steps (e.g., actions or tasks), elements and / or their (e.g., any suitable) combinations.

[0018] In the drawings, for clarity, the thicknesses of layers, films, panels, and / or regions, etc. are exaggerated, where the same reference numerals always refer to the same elements, and their repeated description may not be provided in the specification. In this specification, it will be understood that if (e.g., when) an element is referred to as being "on" another element, the element can be directly on the other element, or there can be intervening elements between them. In the drawings, the thicknesses of some components are exaggerated for the purpose of effectively illustrating the technical content. The same reference numerals always refer to the same elements, and their repeated description may not be provided in the specification.

[0019] Unless specifically stated otherwise in this specification, singular forms of expressions may include plural forms of expressions. In some embodiments, unless specifically stated otherwise, the phrase "A or B" may indicate "A but not B", "B but not A", and "A and B". Here, it should be understood that the terms "comprising", "including", "having" and / or their variants used in this specification do not preclude the presence or addition of one or more other components, but are intended to indicate the presence of the embodied aspects, quantities, steps (e.g., actions or tasks), elements and / or their (e.g., any suitable) combinations.

[0020] As used herein, the term "their combination" may refer to a mixture, stack, composite, copolymer, alloy, blend, or reaction product.

[0021] In one or more embodiments, the term "layer" herein includes not only a shape formed on the entire surface when viewed from a plan view, but also a shape formed on a partial surface.

[0022] It will be understood that although the terms “first,” “second,” “third,” etc. may be used herein to describe one or more suitable elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first element, first component, first region, first layer, or first section described herein may be referred to as a second element, second component, second region, second layer, or second section without departing from the teachings set forth herein.

[0023] As used herein, the term “and / or” includes any combination and all combinations of one or more of the associated listed items. Expressions such as “at least one of...” “one of...” and “selected from...” modify the entire list of elements following (e.g., when) a list of elements, rather than individual elements in the list. For example, the expressions “at least one of a to c,” “at least one of a, b, or c,” and “at least one of a, b, and / or c” may indicate only a, only b, only c, (e.g., simultaneously) both a and b, (e.g., simultaneously) both a and c, (e.g., simultaneously) both b and c, all of a, b, and c, or variants thereof.

[0024] Spatial relative terms such as “under,” “beneath,” “below,” “above,” “on,” etc. may be used herein to easily describe the relationship between one element or feature and another element or feature. It will be understood that the spatial relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation shown in the figures. For example, if (e.g., when) the device in the figures is flipped, an element described as “under” or “beneath” another element or feature will then be oriented “above” the said other element or feature. Thus, the exemplary term “under” may encompass both orientations of above and below (e.g., simultaneously). The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatial relative terms used herein may be interpreted accordingly.

[0025] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the present disclosure. Unless otherwise defined, all terms (including chemical, technical, and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will also be understood that terms (such as those defined in common dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the prior art and the present disclosure, and should not be interpreted in an idealized or overly formal sense.

[0026] Example embodiments are described herein with reference to cross-sectional views that are schematic illustrations of idealized embodiments. As such, variations in the illustrated shapes due to, for example, manufacturing techniques and / or tolerances are to be expected. Accordingly, the embodiments described herein are not to be construed as limited to the particular shapes of regions shown herein, but include, for example, shape deviations resulting from manufacturing. For example, regions shown or described as flat may typically have rough and / or non-linear features. Additionally, the sharp corners shown may be rounded (or circular). Thus, the regions shown in the figures are schematic in nature, and their shapes are not intended to show the exact shape of the regions and are not intended to limit the scope of the claims presented.

[0027] The term "may" will be understood to refer to "one or more embodiments of the present disclosure", some of which include the described element and some of which exclude the element and / or include alternative elements. Similarly, alternative language such as "or" refers to "one or more embodiments of the present disclosure", each of which includes the corresponding listed item.

[0028] As used herein, "consisting essentially of" indicates that any additional components will not substantially affect the chemical, physical, optical, or electrical properties of the semiconductor film.

[0029] Furthermore, in this specification, the phrase "in a plane" or "plan view" indicates viewing the target portion from the top, and the phrase "in a cross-section" indicates viewing a cross-section formed by vertically cutting the target portion from the side.

[0030] As used herein, the term "particle size" refers to the average diameter of a particle when the particle is spherical (e.g., when), and refers to the average major axis length of a particle when the particle is non-spherical (e.g., when). For example, the average particle size can be measured by a method that is very suitable for those skilled in the art. For example, it can be measured by a particle size analyzer, or can be measured by a transmission electron microscope image or a scanning electron microscope image. It can be possible to measure by using the dynamic light scattering method, perform data analysis, count the number of particles in each particle size range, and thus calculate to obtain the average particle size value. Unless otherwise defined, the average particle size can refer to the diameter (D50) of the particles with a cumulative volume of 50% by volume in the particle size distribution. If (e.g., when) measured by laser diffraction, the particles to be measured are dispersed in a dispersion medium, and then introduced into a conventional laser diffraction particle size measuring device (e.g., MT3000 available from Microtrac Co., Ltd.) using ultrasonic waves of about 28 kHz, and after irradiating with a power of 60 W, the average particle size (D50) based on the 50% particle size distribution in the measuring device can be calculated. As used herein, if (e.g., when) no other definition is provided, the average particle size refers to the diameter (D50) of the particles with a cumulative volume of 50% by volume in the particle size distribution obtained by randomly measuring the sizes (diameter or length of the major axis) of about 20 particles in a scanning electron microscope image.

[0031] Figure 1 A simplified conceptual diagram of a rechargeable lithium battery according to one or more embodiments of the present disclosure is shown. Referring to Figure 1 , the rechargeable lithium battery may include a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte ELL.

[0032] The positive electrode 10 and the negative electrode 20 may be spaced apart and / or separated (e.g., separated or disengaged) from each other across the separator 30. The separator 30 may be disposed between the positive electrode 10 and the negative electrode 20. The positive electrode 10, the negative electrode 20, and the separator 30 may be in contact with the electrolyte ELL. The positive electrode 10, the negative electrode 20, and the separator 30 may be impregnated in the electrolyte ELL.

[0033] The electrolyte ELL may be a medium through which lithium ions move between the positive electrode 10 and the negative electrode 20. In the electrolyte ELL, lithium ions may move through the separator 30 toward one of the positive electrode 10 and the negative electrode 20.

[0034] Positive electrode 10

[0035] The positive electrode 10 for a rechargeable lithium battery may include a current collector COL1 and a positive electrode active material layer PAML formed on the current collector COL1. The positive electrode active material layer PAML may include a positive electrode active material, and may further include a binder and / or a conductive material (e.g., an electronic conductor).

[0036] For example, the positive electrode 10 may further include an additive that can serve as a sacrificial positive electrode.

[0037] Based on 100 wt% of the positive electrode active material layer PAML, the amount of the positive electrode active material may be in the range of about 90 wt% to about 99.5 wt%. Based on 100 wt% of the positive electrode active material layer PAML, the amounts of the binder and the conductive material may each independently be about 0.5 wt% to about 5 wt%.

[0038] The binder can be used to improve the adhesion of the positive electrode active material particles to each other, and can also be used to improve the adhesion of the positive electrode active material to the current collector COL1. The binder may include, for example, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, a polymer containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, an epoxy resin, a (meth)acrylic resin, a polyester resin, or nylon, but the present disclosure is not limited thereto.

[0039] The conductive material (e.g., an electronic conductor) can be used to provide conductivity to the electrode, and any suitable conductive material that does not cause a chemical change in the battery can be used as the conductive material (e.g., for providing the battery). Examples of the conductive material may include carbonaceous materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube; metal powders or metal fibers containing at least one (e.g., one or more) selected from copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; and / or any suitable mixture thereof.

[0040] Al can be used as the current collector COL1, but the present disclosure is not limited thereto.

[0041] Positive electrode active material

[0042] The positive electrode active material in the positive electrode active material layer PAML may include a compound (e.g., a lithiated insertion compound) that can reversibly intercalate and deintercalate lithium. For example, the positive electrode active material may include at least one type or kind of composite oxide, and the composite oxide includes lithium and a metal selected from cobalt, manganese, nickel, and / or any suitable combination thereof.

[0043] The composite oxide may include a lithium transition metal composite oxide, for example, 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, and / or a combination thereof (for example, any suitable combination).

[0044] For example, the positive electrode active material may include a compound represented by any one selected from the following chemical formulas: 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 O 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 O 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 O 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 GeO2 (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 Mn2G b O4 (0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1); Li a Mn1-g G g PO4 (0.90 ≤ a ≤ 1.8, 0 ≤ g ≤ 0.5); Li (3-f) Fe2(PO4)3 (0 ≤ f ≤ 2); and Li a FePO4 (0.90 ≤ a ≤ 1.8).

[0045] In the foregoing chemical formulae, A can be Ni, Co, Mn, and / or a combination thereof (e.g., any suitable combination), X can be Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, and / or a combination thereof (e.g., any suitable combination), D can be O, F, S, P, and / or a combination thereof (e.g., any suitable combination), G can be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, and / or a combination thereof (e.g., any suitable combination), and L 1 can be Mn, Al, and / or a combination thereof (e.g., any suitable combination).

[0046] For example, the positive electrode active material can be a high-nickel type positive electrode active material. Based on the amount of the lithium-free metal in 100 mol% of the lithium transition metal composite oxide, the nickel content (e.g., amount) of the high-nickel type positive electrode active material is equal to or greater than about 80 mol%, equal to or greater than about 85 mol%, equal to or greater than about 90 mol%, equal to or greater than about 91 mol%, or equal to or greater than about 94 mol%, and equal to or less than about 99 mol%. The high-nickel type positive electrode active material can achieve high capacity, and thus can be applied to high-capacity and high-density rechargeable lithium batteries.

[0047] Negative electrode 20

[0048] The negative electrode 20 for a rechargeable lithium battery can include a current collector COL2 and a negative electrode active material layer NAML positioned on the current collector COL2. The negative electrode active material layer NAML can include a negative electrode active material, and can also include a binder and / or a conductive material (e.g., an electronic conductor).

[0049] For example, the negative electrode active material layer NAML can include about 90 wt% to about 99 wt% of a negative electrode active material, about 0.5 wt% to about 5 wt% of a binder, and about 0 wt% to about 5 wt% of a conductive material.

[0050] The binder can be used to improve the adhesion of the negative electrode active material particles to each other, and can also be used to improve the adhesion of the negative electrode active material to the current collector COL2. The binder can include a non-aqueous binder, an aqueous binder, a dry binder, and / or a combination thereof (e.g., any suitable combination).

[0051] The non-aqueous binder may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, and / or a combination thereof (e.g., any suitable combination).

[0052] The aqueous binder may include styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluorine-containing elastomer, polyethylene oxide, polyvinylpyrrolidone, epichlorohydrin polymer, polyphosphazene, poly(meth)acrylonitrile, ethylene-propylene-diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and / or a combination thereof (e.g., any suitable combination).

[0053] If (e.g., when) the aqueous binder is used as the negative electrode binder, it may further include a cellulose compound capable of providing viscosity. The cellulose compound may include at least one (e.g., one or more) selected from carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts. The alkali metal may include Na, K, or Li.

[0054] The dry binder may include fibrillatable polymer materials, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and / or a combination thereof (e.g., any suitable combination).

[0055] The conductive material (e.g., electronic conductor) can be used to provide conductivity to the electrode, and any suitable conductive material that does not cause chemical changes in the battery can be used as the conductive material (e.g., for setting up the battery). For example, the conductive material may include: carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube; metal powders or metal fibers including one or more of copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; and / or a mixture thereof (e.g., any suitable mixture).

[0056] The current collector COL2 may include copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and / or a combination thereof (e.g., any suitable combination).

[0057] The electrode density of the negative electrode may be in the range of about 1.0 g / cm³ (g / cc) to about 2.0 g / cc, for example, it may be in the range of about 1.0 g / cc to about 1.8 g / cc, or it may be in the range of about 1.3 g / cc to about 1.8 g / cc.

[0058] In this specification, the term "electrode density" may refer to the density calculated by dividing the measured loading amount of an electrode by the thickness of the electrode after charging and discharging (e.g., once or twice) at 0.1C to 0.2C under the condition that the electrode is sufficiently impregnated with an electrolytic solution.

[0059] If (e.g., when) the electrode density of the negative electrode is within the above range, it may be possible to effectively improve the fast charge / discharge characteristics and cycle life characteristics, e.g., high-rate cycle life characteristics.

[0060] Negative electrode active material

[0061] The negative electrode active material in the negative electrode active material layer NAML may include a material capable of reversibly intercalating and deintercalating lithium ions, lithium metal, a lithium metal alloy, a material capable of doping and undoping lithium, or a transition metal oxide.

[0062] The material capable of reversibly intercalating and deintercalating lithium ions may include carbon-based negative electrode active materials, e.g., crystalline carbon, amorphous carbon, and / or any suitable combination thereof. For example, crystalline carbon may include graphite, such as natural graphite or artificial graphite in an unshaped, flaky, lamellar, spherical, or fibrous form, and amorphous carbon may include soft carbon, hard carbon, mesophase pitch carbon, or calcined coke.

[0063] The lithium metal alloy may include an alloy of lithium and a metal selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn.

[0064] The material capable of doping and undoping lithium may include Si-based negative electrode active materials or Sn-based negative electrode active materials. The Si-based negative electrode active materials may include silicon, a silicon-carbon composite, SiO x (0 < x ≤ 2), an Si-Q alloy (where Q is an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element (excluding Si), a Group 15 element, a Group 16 element, a transition metal, a rare earth element, and / or any suitable combination thereof), and / or any suitable combination thereof. The Sn-based negative electrode active materials may include Sn, SnO2, SnO x (0 < x ≤ 2), Sn-based alloys, and / or any suitable combination thereof.

[0065] The silicon-carbon composite can be a composite of silicon and amorphous carbon. According to one or more embodiments, the silicon-carbon composite can have a structure in which amorphous carbon coats the surface of silicon particles. For example, the silicon-carbon composite can include secondary particles (cores) in which primary silicon particles are assembled and an amorphous carbon coating layer (shells) located on the surface of the secondary particles. Amorphous carbon can also be located between the primary silicon particles. For example, the primary silicon particles can be coated with amorphous carbon. The secondary particles can be dispersed in an amorphous carbon matrix.

[0066] The silicon-carbon composite can also include crystalline carbon. For example, the silicon-carbon composite can include a core containing crystalline carbon and silicon particles, and can also include an amorphous carbon coating layer located on the surface of the core.

[0067] Si-based negative electrode active materials or Sn-based negative electrode active materials can be used in combination with carbon-based negative electrode active materials.

[0068] Separator 30

[0069] Based on the type or kind of the rechargeable lithium battery, the separator 30 can be present between the positive electrode 10 and the negative electrode 20. The separator 30 can include at least one (e.g., one or more) selected from polyethylene, polypropylene, and polyvinylidene fluoride (e.g., among polyethylene, polypropylene, and polyvinylidene fluoride), and can have a multilayer separator thereof, such as one selected from polyethylene / polypropylene double-layer separators, polyethylene / polypropylene / polyethylene triple-layer separators, and polypropylene / polyethylene / polypropylene triple-layer separators.

[0070] The separator 30 can include a porous substrate and a coating layer located on one or both (e.g., opposite) surfaces of the porous substrate, and the coating layer includes an organic material, an inorganic material, and / or a combination thereof (e.g., any suitable combination).

[0071] The porous substrate can be a polymer layer including at least one selected from polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetals, polyamides, polyimides, polycarbonates, polyether ketones, polyaryl ether ketones, polyetherimides, polyamideimides, polybenzimidazoles, polyethersulfones, polyphenylene ethers, cycloolefin copolymers, polyphenylene sulfides, polyethylene naphthalate, glass fibers, Teflon, and polytetrafluoroethylene, or can be a copolymer or mixture including two or more of the materials mentioned herein.

[0072] The organic material can include polyvinylidene fluoride-based copolymers or (meth)acrylic acid copolymers.

[0073] The inorganic material may include inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and / or combinations thereof (e.g., any suitable combination), but the present disclosure is not limited thereto.

[0074] The organic material and the inorganic material may be mixed and present in a coating layer, or may be present as a stack of a coating layer including the organic material and a coating layer including the inorganic material.

[0075] Electrolyte ELL

[0076] The electrolyte ELL for a rechargeable lithium battery may include a non-aqueous organic solvent and a lithium salt.

[0077] The non-aqueous organic solvent may serve as a medium for transporting ions participating in the electrochemical reaction of the battery.

[0078] The non-aqueous organic solvent may include carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, aprotic solvents, and / or combinations thereof (e.g., any suitable combination).

[0079] The carbonate solvents may include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), ethyl methyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), or butylene carbonate (BC).

[0080] The ester solvents may include methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, caprolactone, mevalonolactone, valerolactone, or caprolactone.

[0081] The ether solvents may include dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, or tetrahydrofuran. The ketone solvents may include cyclohexanone. The aprotic solvents may include: nitriles, such as R-CN (wherein R is a hydrocarbon group having a C2 to C20 straight-chain, branched-chain, or cyclic structure and may include double bonds, aromatic rings, or ether groups); amides, such as dimethylformamide; dioxolanes, such as 1,3-dioxolane or 1,4-dioxolane; or sulfolane.

[0082] The non-aqueous organic solvent may be used alone or as a mixture of two or more substances.

[0083] In some embodiments, if (e.g., when) a carbonate solvent is used, a cyclic carbonate and a linear carbonate may be mixed and used, and the cyclic carbonate and the linear carbonate may be mixed at a volume ratio of about 1:1 to about 1:9.

[0084] The lithium salt may be a material dissolved in a non-aqueous organic solvent to serve as a source of lithium ions in a battery, and functions to allow the basic operation of a rechargeable lithium battery and facilitate the movement of lithium ions between the positive electrode and the negative electrode. The lithium salt may include, for example, at least one selected from LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO2, LiAlCl4, LiPO2F2, LiCl, LiI, LiN(SO3C2F5)2, Li(FSO2)2N, lithium bis(fluorosulfonyl)imide (LiFSI), LiC4F9SO3, LiN(C x F 2x+1 SO2)(C y F 2y+1 SO2) (where x and y are integers between 1 and 20), lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluoro bis(oxalato)phosphate (LiDFOB), and lithium bis(oxalato)borate (LiBOB).

[0085] Rechargeable lithium battery

[0086] Based on the shape of the rechargeable lithium battery, the rechargeable lithium battery may be classified into cylindrical, prismatic, pouch-type, and coin-type (categories). Figures 2 to 5 A simplified diagram of a rechargeable lithium battery according to one or more embodiments is shown. Figure 2 A cylindrical battery is shown, Figure 3 A prismatic battery is shown, and Figure 4 and Figure 5 A pouch-type (or category) battery is shown. Referring to Figures 2 to 4 , the rechargeable lithium battery 100 may include an electrode assembly 40 and a housing 50 that houses the electrode assembly 40. In the electrode assembly 40, a separator 30 is disposed between the positive electrode 10 and the negative electrode 20. The positive electrode 10, the negative electrode 20, and the separator 30 may be impregnated with an electrolyte. As Figure 2 shown, the rechargeable lithium battery 100 may include a sealing member 60 for sealing the housing 50. In some embodiments, as Figure 3 shown, the rechargeable lithium battery 100 may include a positive electrode lead tab 11, a positive electrode terminal 12, a negative electrode lead tab 21, and a negative electrode terminal 22. As Figure 4 shown, the rechargeable lithium battery 100 may include electrode tabs, such as a positive electrode tab 71 and a negative electrode tab 72, that serve as a circuit path for inducing current generated in the electrode assembly 40 from the outside. AsFigure 5 As shown, the rechargeable lithium battery 100 may include an electrode tab 70 that serves as a circuit path for inducing a current generated in the electrode assembly 40 from the outside.

[0087] In one or more embodiments described herein, a detailed description of technical features that duplicate the technical features discussed with reference to Figures 1 to 5 will not be provided, and their differences will be discussed in more detail.

[0088] Figure 6 A cross-sectional view of an electrode for a rechargeable lithium battery according to one or more embodiments of the present disclosure is shown. Referring to Figure 6 , a current collector COL and a multi-active material layer AML on one surface of the current collector COL may be provided. The multi-active material layer AML may include a first electrode mixture layer AML1 on the current collector COL, a second electrode mixture layer AML2 on the first electrode mixture layer AML1, and a third electrode mixture layer AML3 on the second electrode mixture layer AML2. Each of the first electrode mixture layer AML1, the second electrode mixture layer AML2, and the third electrode mixture layer AML3 may include an electrode active material ACT and a binder BND.

[0089] According to one or more embodiments of the present disclosure, the electrode for a rechargeable lithium battery may be a positive electrode or a negative electrode. If (e.g., when) the electrode is a positive electrode, the electrode active material ACT may be a positive electrode active material such as lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate-based compounds, cobalt-free nickel manganese-based oxides, and / or any suitable combination thereof.

[0090] If (e.g., when) the electrode is a negative electrode, the electrode active material ACT may be a negative electrode active material such as Si-based materials, Sn-based materials, carbon-based materials, etc. The carbon-based materials may include at least one selected from crystalline artificial graphite, crystalline natural graphite, amorphous hard carbon, low-crystalline soft carbon, carbon black, acetylene black, Ketjen black, conductive carbon black (super P), graphene, and fibrous carbon.

[0091] In one or more embodiments, the first electrode mixture layer AML1, the second electrode mixture layer AML2, and the third electrode mixture layer AML3 may include the same electrode active material. In one or more embodiments, the first electrode mixture layer AML1, the second electrode mixture layer AML2, and the third electrode mixture layer AML3 may include different electrode active materials.

[0092] The first electrode mixture layer AML1, the second electrode mixture layer AML2, and the third electrode mixture layer AML3 may have different binder dosages (e.g., may each independently have different binder dosages). In the present disclosure, the binder dosage may be the ratio of the weight of the binder in the electrode mixture layer to the total weight of the electrode mixture layer. The binder dosage of the first electrode mixture layer AML1 may be greater than the binder dosage of the second electrode mixture layer AML2, and the binder dosage of the second electrode mixture layer AML2 may be greater than the binder dosage of the third electrode mixture layer AML3.

[0093] The difference in the binder ratio between the first electrode mixture layer AML1 and the second electrode mixture layer AML2 may be in the range of about 0.1 to about 0.6, e.g., may be in the range of about 0.1 to about 0.4 or about 0.2 to about 0.3. The difference in the binder ratio between the second electrode mixture layer AML2 and the third electrode mixture layer AML3 may be in the range of about 0 to about 0.4, e.g., may be in the range of about 0.1 to about 0.4 or about 0.2 to about 0.3.

[0094] In this specification, the term "binder ratio" may refer to the ratio of the weight of the binder included in each layer to the total weight of the binder included in the first electrode mixture layer AML1, the second electrode mixture layer AML2, and the third electrode mixture layer AML3. For example, if (e.g., when) 1 is given as the total weight of the binder included in the first electrode mixture layer AML1, the second electrode mixture layer AML2, and the third electrode mixture layer AML3, the term "binder ratio" may refer to the weight ratio of the binder included in each layer. The binder ratio may be a dimensionless value, and the sum of the binder ratios in each layer may be 1. In the electrodes according to one or more embodiments of the disclosure, since the electrode mixture layers have substantially the same base area, the binder ratio of each electrode mixture layer can be obtained by Equation 1.

[0095] [Equation 1]

[0096]

[0097] For example, the first electrode mixture layer AML1 may have a binder dosage of about 5 wt% and a thickness THK1 of about 20 micrometers (μm), the second electrode mixture layer AML2 may have a binder dosage of about 2 wt% and a thickness THK2 of about 40 μm, and the third electrode mixture layer AML3 may have a binder dosage of about 0.5 wt% and a thickness THK3 of about 40 μm. In this case, the first electrode mixture layer AML1 may have a binder ratio of about 0.5, the second electrode mixture layer AML2 may have a binder ratio of about 0.4, and the third electrode mixture layer AML3 may have a binder ratio of about 0.1.

[0098] The binder dosage of the first electrode mixture layer AML1 may be greater than that of the second electrode mixture layer AML2, and with respect to the total weight of the first electrode mixture layer AML1, the binder dosage of the first electrode mixture layer AML1 may be in the range of about 0.5 wt% to about 10 wt%, for example, it may be in the range of about 2 wt% to about 8 wt%. The binder dosage of the first electrode mixture layer AML1 in the direction of contact with the current collector COL may be greater than that of the second electrode mixture layer AML2 and the third electrode mixture layer AML3 in the direction of contact with the current collector COL, and this configuration may increase the adhesion strength between the current collector and the electrode mixture layer.

[0099] If (for example, when) the binder dosage of the first electrode mixture layer AML1 is excessively (or substantially) greater than the above range, the amounts of the active material and the conductive material will relatively decrease. Therefore, the internal resistance of the electrode will increase, the conductivity will decrease, and the capacity and energy density will decrease.

[0100] The binder dosage of the second electrode mixture layer AML2 may be less than that of the first electrode mixture layer AML1 and greater than that of the third electrode mixture layer AML3. With respect to the total weight of the second electrode mixture layer AML2, the binder dosage of the second electrode mixture layer AML2 may be in the range of about 0.5 wt% to about 10 wt%, for example, it may be in the range of about 0.5 wt% to about 4 wt%, or it may be in the range of about 2 wt% to about 4 wt%. The binder dosage of the third electrode mixture layer AML3 may be less than that of the second electrode mixture layer AML2, and with respect to the total weight of the third electrode mixture layer AML3, the binder dosage of the third electrode mixture layer AML3 may be in the range of about 0.1 wt% to about 5 wt%, for example, it may be in the range of about 0.1 wt% to about 4 wt%. The reduction in the binder dosages of the second electrode mixture layer AML2 and the third electrode mixture layer AML3 may cause the electrode to have high conductivity and improved capacity characteristics.

[0101] If (e.g., when) the difference in the amount of binder between adjacent electrode mixture layers is greater than about 5 wt%, significant compositional non-uniformity of the electrodes can cause delamination between adjacent electrode mixture layers. According to one or more embodiments of the present disclosure, the multi-active material layer AML can be formed of three or more layers, and the amount of binder in the second electrode mixture layer AML2 can be greater than that in the third electrode mixture layer AML3. The amount of binder can have a gradient that gradually decreases in the direction from the first electrode mixture layer AML1 to the third electrode mixture layer AML3.

[0102] As discussed herein, if (e.g., when) the amount of binder in the electrode mixture layer gradually decreases as the distance from the current collector COL increases, significant compositional non-uniformity between adjacent electrode mixture layers can be reduced to lower the interfacial resistance. Therefore, delamination between adjacent electrode mixture layers can be prevented or reduced.

[0103] The binder BND can include a non-aqueous binder, an aqueous binder, a dry binder, and / or a combination thereof (e.g., any suitable combination). For example, the binder BND can include at least one selected from polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), mussel protein, polyolefin binders, and silane binders, and can include, for example, a styrene-butadiene rubber (SBR) binder.

[0104] In one or more embodiments, the first electrode mixture layer AML1, the second electrode mixture layer AML2, and the third electrode mixture layer AML3 can include the same binder. In one or more embodiments, the first electrode mixture layer AML1, the second electrode mixture layer AML2, and the third electrode mixture layer AML3 can include different binders.

[0105] According to one or more embodiments of the present disclosure, the electrode for a rechargeable lithium battery can further include a conductive material CDM for improving conductivity. Any conductive material can be used as the conductive material CDM unless it causes a chemical change. In one or more embodiments, the first electrode mixture layer AML1, the second electrode mixture layer AML2, and the third electrode mixture layer AML3 can include the same conductive material. In one or more embodiments, the first electrode mixture layer AML1, the second electrode mixture layer AML2, and the third electrode mixture layer AML3 can include different conductive materials.

[0106] According to one or more embodiments of the present disclosure, an electrode for a rechargeable lithium battery may further include a filler to inhibit or reduce the swelling of the electrode. For example, the filler may include olefin polymers such as polyethylene and polypropylene, or fibrous materials such as glass fiber and carbon fiber. The type or kind of the filler may be the same for each layer, or the types (kinds) of the fillers included in two or more layers may be different from each other.

[0107] Return reference Figure 6 , the first thickness THK1 of the first electrode mixture layer AML1 may be less than the second thickness THK2 of the second electrode mixture layer AML2 and the third thickness THK3 of the third electrode mixture layer AML3. The second thickness THK2 may be substantially the same as or different from the third thickness THK3.

[0108] For example, the first thickness THK1, the second thickness THK2, and the third thickness THK3 may have a ratio of a:1:1. In this case, "a" may be in the range of about 0.3 to about 0.7, for example, may be in the range of about 0.3 to about 0.6 or about 0.4 to about 0.6.

[0109] In some embodiments, since the current collector COL is coated with the first electrode mixture layer AML1 having a small thickness (e.g., the first thickness THK1) close to the current collector COL, an increased adhesion performance may exist between the multi-active material layer AML and the current collector COL. In some embodiments, since the current collector COL is coated with the second electrode mixture layer AML2 and the third electrode mixture layer AML3 having a large thickness (e.g., the second thickness THK2 and the third thickness THK3) away from the current collector COL, the amount of the active material may be increased, which may result in an improvement in the lithium conductivity. If (e.g., when) the first thickness THK1, the second thickness THK2, and the third thickness THK3 satisfy the above range, the battery may exhibit fast charging performance while maintaining high stability.

[0110] The rechargeable lithium battery according to one or more embodiments of the present disclosure may be used in (e.g., applied to) motor vehicles, mobile phones, and / or any other electrical devices, but the present disclosure is not limited thereto.

[0111] Terms such as "substantially", "about", and "approximate" are used as relative terms rather than degree terms and are intended to explain the inherent deviation of measured or calculated values that would be recognized by a person of ordinary skill in the art. They may include the stated value and an acceptable range of deviation determined by a person of ordinary skill in the art considering the limitations and errors associated with the measurement of the quantity. For example, "about" may refer to one or more standard deviations, or ±30%, ±20%, ±10%, ±5% of the stated value.

[0112] The numerical ranges disclosed herein include and are intended to disclose all sub-ranges subsumed therein with the same numerical precision. For example, the range of "1.0 to 10.0" includes all sub-ranges having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Accordingly, the applicant reserves the right to amend this specification and the claims to expressly recite any sub-ranges subsumed within the ranges expressly recited herein.

[0113] Embodiments and comparative examples of the present disclosure will be described below. However, the following examples are merely one or more possible embodiments of the present disclosure, and the present disclosure is not limited to the following examples.

[0114] Example

[0115] Example 1

[0116] Preparation of the first negative electrode mixture slurry

[0117] Using styrene-butadiene rubber (SBR) as the binder, and using a silicon-graphite composite and graphite in a weight ratio of 95:5 as the negative electrode active material, the binder, the negative electrode active material, and carbon black (conductive material) are weighed in a ratio of 5.8:90:4.2, and then added to distilled water and mixed to prepare a negative electrode mixture slurry for the first negative electrode mixture layer.

[0118] Preparation of the second negative electrode mixture slurry

[0119] Using styrene-butadiene rubber (SBR) as the binder, and using a silicon-graphite composite and graphite in a weight ratio of 95:5 as the negative electrode active material, the binder, the negative electrode active material, and carbon black (conductive material) are weighed in a ratio of 1.7:95:3.3, and then added to distilled water and mixed to prepare a negative electrode mixture slurry for the second negative electrode mixture layer.

[0120] Preparation of the third negative electrode mixture slurry

[0121] Using styrene-butadiene rubber (SBR) as the binder, and using a silicon-graphite composite and graphite in a weight ratio of 95:5 as the negative electrode active material, the binder, the negative electrode active material, and carbon black (conductive material) are weighed in a ratio of 0.4:95:4.6, and then added to distilled water and mixed to prepare a negative electrode mixture slurry for the third negative electrode mixture layer.

[0122] Manufacture of the negative electrode

[0123] The first negative electrode mixture slurry is coated on a copper current collector with a thickness of 20 micrometers (μm), the second negative electrode mixture slurry is coated on the first negative electrode mixture layer with a thickness of 40 μm, the third negative electrode mixture slurry is coated on the second negative electrode mixture layer with a thickness of 40 μm, and then all (e.g., all) slurry components are dried and roll-pressed to manufacture a negative electrode with a total thickness of 80 μm.

[0124] The binder ratio and binder distribution of each layer are listed in Table 1 and Figure 7 in.

[0125] Example 2

[0126] A negative electrode is manufactured by the same method as in Example 1, except that the first negative electrode mixture slurry is coated with a thickness of 15 μm when manufacturing the negative electrode of Example 1.

[0127] The binder ratio and binder distribution of each layer are listed in Table 1 and Figure 7 in.

[0128] Example 3

[0129] A negative electrode is manufactured by the same method as in Example 1, except that the first negative electrode mixture slurry is coated with a thickness of 25 μm when manufacturing the negative electrode of Example 1.

[0130] The binder ratio and binder distribution of each layer are listed in Table 1 and Figure 7 in.

[0131] [Comparative Example 1]

[0132] Preparation of the first negative electrode mixture slurry

[0133] Styrene-butadiene rubber (SBR) is used as the binder, and a silicon-graphite composite and graphite with a weight ratio of 95:5 are used as the negative electrode active material, so that the binder, negative electrode active material, and carbon black (conductive material) are weighed in a ratio of 3.6:95:1.4, and then added to distilled water and mixed to prepare a negative electrode mixture slurry for the first negative electrode mixture layer.

[0134] Preparation of the second negative electrode mixture slurry

[0135] Styrene-butadiene rubber (SBR) is used as the binder, and a silicon-graphite composite and graphite with a weight ratio of 95:5 are used as the negative electrode active material, so that the binder, negative electrode active material, and carbon black (conductive material) are weighed in a ratio of 0.4:95:4.6, and then added to distilled water and mixed to prepare a negative electrode mixture slurry for the second negative electrode mixture layer.

[0136] Manufacture of the negative electrode

[0137] The first negative electrode mixture slurry is coated on a copper current collector with a thickness of 50 μm, the second negative electrode mixture slurry is coated on the first negative electrode mixture layer with a thickness of 50 μm, and then all (e.g., all) slurry components are dried and roll-pressed to fabricate a negative electrode with a total thickness of 80 μm.

[0138] The binder ratio and binder distribution of each layer are listed in Table 1 and Figure 8 in.

[0139] [Comparative Example 2]

[0140] Preparation of the first negative electrode mixture slurry

[0141] Styrene-butadiene rubber (SBR) is used as a binder, and a silicon-graphite composite and graphite with a weight ratio of 95:5 are used as negative electrode active materials, such that the binder, negative electrode active materials, and carbon black (conductive material) are weighed in a ratio of 8.4:90:1.6, and then added to distilled water and mixed to prepare a negative electrode mixture slurry for the first negative electrode mixture layer.

[0142] Preparation of the second negative electrode mixture slurry

[0143] Styrene-butadiene rubber (SBR) is used as a binder, and a silicon-graphite composite and graphite with a weight ratio of 95:5 are used as negative electrode active materials, such that the binder, negative electrode active materials, and carbon black (conductive material) are weighed in a ratio of 0.4:95:4.6, and then added to distilled water and mixed to prepare a negative electrode mixture slurry for the second negative electrode mixture layer.

[0144] Fabrication of the negative electrode

[0145] The first negative electrode mixture slurry is coated on a copper current collector with a thickness of 20 μm, the second negative electrode mixture slurry is coated on the first negative electrode mixture layer with a thickness of 80 μm, and then all the slurry is dried and roll-pressed to fabricate a negative electrode with a total thickness of 80 μm.

[0146] The binder ratio and binder distribution of each layer are listed in Table 1 and Figure 8 in.

[0147] [Comparative Example 3]

[0148] A negative electrode is fabricated by the same method as in Example 1, except that the first negative electrode mixture slurry is coated with a thickness of 10 μm when fabricating the negative electrode of Example 1.

[0149] The binder ratio and binder distribution of each layer are listed in Table 1 and Figure 8 in.

[0150] [Comparative Example 4]

[0151] The negative electrode was fabricated by the same method as in Example 1, except that the first negative electrode mixture slurry was coated at a thickness of 30 μm during the fabrication of the negative electrode of Example 1.

[0152] The binder ratio and binder distribution of each layer are listed in Table 1 and Figure 8 .

[0153] Table 1

[0154]

[0155] Evaluation Example: Adhesion Strength of Electrode Plate

[0156] The adhesion strength tests were performed on the negative electrodes fabricated in Examples 1 to 3 and Comparative Examples 1 to 4. After slicing the surface of each of the negative electrodes fabricated in Examples 1 to 3 and Comparative Examples 1 to 4 and fixing it on a glass slide, the 180° peel strength was measured while peeling off the electrode current collector, and the results are listed in Figure 9 .

[0157] Referring to Figure 9 , it was determined that the adhesion strength in the case where the multi-active material layer is formed of three layers (e.g., when) is superior to the adhesion strength in the case where the multi-active material layer is formed of only two layers (e.g., when). In addition, it was determined that if (e.g., when) the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer have a certain thickness ratio, the adhesion strength increases.

[0158] According to one or more embodiments of the present disclosure, an electrode for a rechargeable lithium battery may include a multi-active material layer. The thickness of the first electrode mixture layer adjacent to the current collector may be less than the thickness of the second electrode mixture layer spaced apart from and / or separated (e.g., spaced or separated) from the current collector. The first electrode mixture layer and the second electrode mixture layer may have different amounts of binder. Accordingly, the adhesion strength between the current collector and the active material layer may increase. Accordingly, the rechargeable lithium battery according to the present disclosure may maintain excellent or appropriate capacity and density characteristics.

[0159] The battery management system (BMS) device and / or any other related device or component according to embodiments of the present disclosure described herein can be implemented using any suitable hardware, firmware (e.g., application specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, the components of the device can be formed on a single integrated circuit (IC) chip or on separate IC chips. Additionally, the components of the device can be implemented on a flexible printed circuit film, tape carrier package (TCP), printed circuit board (PCB), or formed on a substrate. Further, the components of the device can be processes or threads running on one or more processors in one or more computing devices that execute computer program instructions and interact with other system components for performing the functions described herein. The computer program instructions are stored in a memory, which can be implemented in a computing device using standard memory devices (such as, by way of example, random access memory (RAM)). The computer program instructions can also be stored in other non-transitory computer-readable media (such as, by way of example, CD-ROM, flash drive, etc.). Moreover, those skilled in the art should recognize that, without departing from the scope of the present disclosure, the functions of a computing device can be combined or integrated into a single computing device, or the functions of a particular computing device can be distributed across one or more other computing devices.

[0160] Although the present disclosure has been described in connection with what are presently considered to be example embodiments, it will be understood that the present disclosure is not limited to the disclosed example embodiments and is intended to cover one or more suitable modifications and equivalent arrangements included within the spirit and scope of the appended claims and their equivalents. Accordingly, the above embodiments should be understood as examples and in no way limit the present disclosure.

Claims

1. An electrode, the electrode comprising: A current collector; And A multi-active material layer on the current collector, The multi-active material layer comprising: a first electrode mixture layer on the current collector; a second electrode mixture layer on the first electrode mixture layer; and a third electrode mixture layer on the second electrode mixture layer, each of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer comprising an electrode active material and a binder, the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer each independently having a binder dosage, their binder dosages being different from each other, a first thickness of the first electrode mixture layer being less than a second thickness of the second electrode mixture layer, and the first thickness being less than a third thickness of the third electrode mixture layer, Wherein the electrode is for a rechargeable lithium battery.

2. The electrode according to claim 1, wherein, The second thickness is the same as the third thickness.

3. The electrode according to claim 1, wherein, The first thickness, the second thickness, and the third thickness have a ratio of a:1:1, Wherein a is from 0.3 to 0.

7.

4. The electrode according to claim 1, wherein, The binder of each of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer comprises at least one selected from polyvinylidene fluoride, styrene-butadiene rubber, mussel protein, polyolefin binders, and silane binders.

5. The electrode according to claim 1, wherein The binder of each of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer comprises a styrene-butadiene rubber binder.

6. The electrode according to claim 1, wherein The binder dosage of the first electrode mixture layer is greater than the binder dosage of the second electrode mixture layer, and Wherein the binder dosage of the first electrode mixture layer is greater than the binder dosage of the third electrode mixture layer.

7. The electrode according to claim 6, wherein The binder dosage of the second electrode mixture layer is greater than the binder dosage of the third electrode mixture layer.

8. The electrode according to claim 1, wherein, The electrode is a multi-layer positive electrode or a multi-layer negative electrode.

9. The electrode according to claim 1, wherein, At least one selected from the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer further comprises a conductive material.

10. An electrode, the electrode comprising: A current collector; And A multi-active material layer on the current collector, The multi-active material layer comprising: a first electrode mixture layer on the current collector; a second electrode mixture layer on the first electrode mixture layer; and a third electrode mixture layer on the second electrode mixture layer, each of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer may comprise an electrode active material and a binder, the difference in the binder ratio between the first electrode mixture layer and the second electrode mixture layer being from 0.1 to 0.6, and the difference in the binder ratio between the second electrode mixture layer and the third electrode mixture layer being from 0 to 0.4, Wherein the electrode is for a rechargeable lithium battery.

11. The electrode according to claim 10, wherein, The amount of the binder in the multi-active material layer has a gradient decreasing in the direction from the first electrode mixture layer to the third electrode mixture layer.

12. The electrode according to claim 10, wherein, The binder dosage of the first electrode mixture layer is greater than that of the second electrode mixture layer, and the binder dosage of the first electrode mixture layer is 2 wt% to 8 wt%.

13. The electrode according to claim 10, wherein The binder dosage of the second electrode mixture layer is less than that of the first electrode mixture layer and greater than that of the third electrode mixture layer, and the binder dosage of the second electrode mixture layer is 0.5 wt% to 4 wt%.

14. The electrode according to claim 10, wherein, The binder dosage of the third electrode mixture layer is less than that of the second electrode mixture layer, and the binder dosage of the third electrode mixture layer is 0.1 wt% to 4 wt%.

15. The electrode according to claim 10, wherein, The first thickness of the first electrode mixture layer is less than the second thickness of the second electrode mixture layer, and the first thickness is less than the third thickness of the third electrode mixture layer.

16. The electrode according to claim 15, wherein The first thickness, the second thickness, and the third thickness have a ratio of a:1:1, where a is 0.3 to 0.

7.

17. The electrode according to claim 10, wherein, The binder of each of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer includes at least one selected from polyvinylidene fluoride, styrene-butadiene rubber, mussel protein, polyolefin binders, and silane binders.

18. The electrode according to claim 10, wherein, The binder of each of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer includes a styrene-butadiene rubber binder.

19. The electrode according to claim 10, wherein, One of the first electrode mixture layer, the second electrode mixture layer, and the third electrode mixture layer further includes a conductive material.

20. A rechargeable lithium battery, the rechargeable lithium battery including the electrode according to any one of claims 1 to 19.

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