Dry binder, electrode and rechargeable lithium battery including same, and method of manufacturing electrode

Abstract

Provided are a dry binder including a cross-linking reaction product of a polyurethane-based polymer cross-linked by an epoxy cross-linking agent, an electrode including the dry binder, a rechargeable lithium battery including the dry binder, and a method of manufacturing the electrode.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2024-0135944, filed on October 7, 2024, and Korean Patent Application No. 10-2025-0139310, filed on September 25, 2025, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entireties by reference. TECHNICAL FIELD

[0002] The present disclosure relates to a dry binder, an electrode including the same, and a rechargeable lithium battery including the same. BACKGROUND

[0003] As the increasing presence of electronic devices using batteries, such as exemplified by mobile phones, laptop computers, electric vehicles, and the like, the demand for rechargeable batteries that are small, light in weight, and relatively high in capacity is increasing. In particular, because rechargeable lithium batteries are light in weight and have a high energy density, rechargeable lithium batteries can be advantageous as power sources for portable devices.

[0004] Rechargeable lithium batteries include positive and negative electrodes including active materials capable of intercalating and deintercalating lithium ions and an electrolyte solution that generates electric energy through oxidation and reduction reactions when lithium ions are intercalated and deintercalated from the positive and negative electrodes.

[0005] Transition metal compounds, such as exemplified by lithium cobalt-based oxides, lithium nickel-based oxides, and lithium manganese-based oxides, are mainly used as positive electrode active materials for rechargeable lithium batteries, and crystalline carbon materials, such as exemplified by natural graphite or artificial graphite, or amorphous carbon materials are used as negative electrode active materials.

[0006] Binders are used in various components of these rechargeable lithium batteries. Binders should have high adhesion strength, but binders having high adhesion strength can generally have the disadvantage of increasing resistance. SUMMARY

[0007] Some example embodiments include a dry binder having high adhesion strength, being environmentally friendly, and can be used in a dry process.

[0008] Some example embodiments include an electrode having desired or improved tensile strength and adhesion strength by including a dry binder.

[0009] Some example embodiments provide a rechargeable lithium battery having desired or improved cycle life characteristics by including a dry binder.

[0010] In some example embodiments, the dry binder includes a crosslinked reaction product of a polyurethane-based polymer crosslinked by an epoxy crosslinking agent.

[0011] In some example embodiments, an electrode for a rechargeable lithium battery includes the aforementioned dry binder and an electrode active material.

[0012] In some example embodiments, a rechargeable lithium battery includes a positive electrode, a negative electrode, and an electrolyte, wherein at least one of the negative electrode and the positive electrode includes the aforementioned dry binder.

[0013] In some example embodiments, a method for manufacturing an electrode includes dry mixing an electrode active material, a binder, and a conductive material to prepare a composition for forming an electrode, and coating the composition for forming an electrode on an electrode current collector to form the electrode. The binder includes a crosslinked reaction product of a polyurethane-based polymer crosslinked by an epoxy crosslinking agent.

[0014] Because the dry binder does not use fluorine in the dry electrode manufacturing process, the dry binder is environmentally friendly, and can improve tensile strength and adhesion strength. By including the dry binder, an electrode having desired or improved tensile strength and adhesion strength and a rechargeable lithium battery having desired or improved cycle life characteristics can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figures 1 to 4 is a view schematically showing a rechargeable lithium battery according to some example embodiments. DETAILED DESCRIPTION

[0016] Hereinafter, example embodiments are described in detail so that those skilled in the art can easily implement them. However, the present disclosure can be implemented in many different forms, and is not interpreted to be limited to the example embodiments set forth herein.

[0017] The terms used herein are only used to describe example embodiments, and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, singular expressions include plural expressions.

[0018] As used herein, "combination thereof" means a mixture, a laminate, a composite, a copolymer, an alloy, a blend, a reaction product, etc. of ingredients.

[0019] Here, it should be understood that terms such as "include", "comprise" or "have" are intended to designate the presence of features, numbers, steps, elements or combinations thereof described, but do not exclude the presence or addition of one or more other features, numbers, steps, elements or combinations thereof.

[0020] In the drawings, the thicknesses of layers, films, panels, regions, etc., are exaggerated for clarity. Like reference numerals designate like elements throughout the specification. It is to be understood that when a quantity is described as "over" or "under" another quantity, that quantity can be directly on the other quantity or an intervening quantity can also be present. Conversely, when a quantity is described as "directly on" another quantity, there is no intervening quantity present.

[0021] Further, a "layer" herein includes not only a shape formed on an entire surface when viewed from a plan view, but also a shape formed on a partial surface.

[0022] The average particle diameter can be measured by a method known to those skilled in the art (for example, by a particle size analyzer, or by a transmission electron microscope image or a scanning electron microscope image). Alternatively, it can be measured by using a dynamic light scattering method, performing data analysis, counting the number of particles in each particle size range, and obtaining an average particle diameter value therefrom. Unless otherwise defined, the average particle diameter can refer to the diameter of a particle having a cumulative volume of 50% by volume in a particle size distribution (D 50 ). As used herein, unless otherwise provided by definition, the average particle diameter refers to the diameter of a particle having a cumulative volume of 50% by volume in a particle size distribution obtained by randomly measuring the size (diameter or major axis length) of about 20 particles in a scanning electron microscope image (D 50 ).

[0023] Herein, "or" is not to be construed as an exclusive sense, for example, "A or B" is construed to include A, B, A+B, etc.

[0024] Herein, "dry binder" means a binder that can be used to manufacture an electrode in a dry manner without using a solvent. For example, "dry binder" refers to a binder used in a dry electrode in which an active material, a dry binder, and an optional conductive material are mixed without a solvent to prepare an active material layer composition, and an electrode is prepared using the composition.

[0025] When the term "about" or "substantially" is used in the present specification in connection with a numerical value, it means that the relevant numerical value includes a tolerance of ±10% around the stated numerical value. When a range is specified, the range includes all values therebetween, such as in increments of 0.1%.

[0026] Dry binder In some example embodiments, the dry binder includes a cross-linking reaction product in which a polyurethane-based polymer is cross-linked by an epoxy cross-linking agent.

[0027] The dry binder makes the electrode active material particles adhere to each other, and makes the active material adhere to the current collector. Research has been conducted on developing a dry electrode manufacturing process that is environmentally friendly and efficient in manufacturing. Fluorine-based binders such as, for example, polytetrafluoroethylene (PTFE) can be used as the dry binder. However, due to recent environmental issues, it can be advantageous to replace the fluorine-based binder such as PTFE with a more environmentally friendly material.

[0028] Accordingly, binders that do not contain fluorine atoms are being researched. However, most binders that do not contain fluorine atoms generally have poor adhesion properties, and thus do not reach the adhesion level of PTFE.

[0029] Accordingly, a dry binder that has desirable or improved adhesion properties and can improve battery performance as a replacement material for fluorine-based binders such as PTFE can be advantageous.

[0030] Accordingly, in some example embodiments, by introducing a binder having improved adhesion properties, electrolyte solution stability, and current density, etc. into an electrode without containing fluorine atoms, a dry binder capable of improving battery performance is provided.

[0031] In some example embodiments, the polyurethane-based polymer can include a structural unit represented by Chemical Formula 1.

[0032] Chemical Formula 1:

[0033] In Chemical Formula 1, R 1 is or includes a linking group, the linking group is independently or includes a substituted or unsubstituted C1 to C20 alkylene, a substituted or unsubstituted C3 to C20 cycloalkylene, or a combination thereof, n is an integer in the range of 1 to 300, and represents a connection site to the main chain.

[0034] The substituted or unsubstituted C1 to C20 alkylene can include a structural unit of -(CH2) n wherein n is an integer in the range of 1 to 14.

[0035] At least one non-adjacent methylene (-(CH2)-) among the linking groups can be replaced with at least one of -NH-, -C(=O)-, and a combination thereof.

[0036] In some example embodiments, the polyurethane-based polymer can further include at least one of an ether group-containing structural unit, an ester group-containing structural unit, and a combination thereof.

[0037] The polyurethane-based polymer including the structural unit including an ether group can include a structural unit represented by Chemical Formula 1-1, the polyurethane-based polymer including the structural unit including an ester group can include a structural unit represented by Chemical Formula 1-2, and the polyurethane-based polymer including the structural unit including an ether group and the structural unit including an ester group can include a structural unit represented by Chemical Formula 1-3.

[0038] Chemical Formula 1-1: .

[0039] Chemical Formula 1-2: .

[0040] Chemical Formula 1-3: .

[0041] In Chemical Formula 1-1, Chemical Formula 1-2, and Chemical Formula 1-3, R 1 , R 3 , R 4 , and R 5 are each independently or include a linking group, the linking group is or includes a substituted or unsubstituted C1 to C20 alkylene, a substituted or unsubstituted C3 to C20 cycloalkylene, or a combination thereof, x, y, and z are mole fractions of each structural unit and are each independently in a range of about 0 to about 1, n is an integer in a range of 1 to about 200, and represents a connection site with a main chain.

[0042] The content of each of the structural unit including an ether group, the structural unit including an ester group, and the combination of the structural unit including an ether group and the structural unit including an ester group can be in a range of about 0 mol% to about 70 mol% based on 100 mol% of the polyurethane-based polymer.

[0043] The substituted or unsubstituted C1 to C20 alkylene can include a structural unit of -(CH2) n , where n is an integer in a range of 2 to 14.

[0044] At least one non-adjacent methylene (-(CH2)-) among the linking groups can be replaced with at least one of -NH-, -C(=O)-, and a combination thereof.

[0045] In some example embodiments, R 1 , R 3 , R 4 , and R 5 may include any one of the moieties of Group 1.

[0046] Group 1: ; ; ; .

[0047] In Group 1, represents a bonding site to the main chain.

[0048] In some example embodiments, the content of the polyurethane-based polymer can be in the range of about 60 parts by weight to about 95 parts by weight, for example, in the range of about 70 parts by weight to about 90 parts by weight, based on 100 parts by weight of the dry binder. Within the above range, the electrode manufacturing process using the dry binder is easier, and the adhesion strength of the electrode can be improved.

[0049] The weight average molecular weight (Mw) of the polyurethane-based polymer can be in the range of about 600 g / mol to about 800,000 g / mol. Within the above range, the electrode manufacturing process using the dry binder is easier, and the adhesion strength of the electrode can be improved.

[0050] The epoxy crosslinking agent can include at least one of the compounds represented by Chemical Formula 2-1, Chemical Formula 2-2, Chemical Formula 2-3, Chemical Formula 2-4, and Chemical Formula 2-5.

[0051] Chemical Formula 2-1: .

[0052] Chemical Formula 2-2: .

[0053] Chemical Formula 2-3: .

[0054] Chemical Formula 2-4: .

[0055] Chemical Formula 2-5: .

[0056] In Chemical Formula 2-1, Chemical Formula 2-2, Chemical Formula 2-3, Chemical Formula 2-4, and Chemical Formula 2-5, R 6 , R 10 , and R 11 each independently is or includes a substituted or unsubstituted C1 to C6 alkylene, R 7 , R 8 , and R 9the same or different, and each independently is or includes hydrogen (H), deuterium, or a substituted or unsubstituted C1 to C6 alkyl group, n is an integer greater than or equal to 1 and less than or equal to about 30, and a, b, and c are each independently an integer greater than or equal to 0 and less than or equal to 4.

[0057] In some example embodiments, the content of the epoxy crosslinking agent can be in the range of about 5 parts by weight to about 40 parts by weight, for example, in the range of about 10 parts by weight to about 30 parts by weight, based on 100 parts by weight of the dry binder. Within the above range, the crosslinking agent can form a crosslinking bond with the polyurethane-based polymer to improve the adhesion strength.

[0058] The weight average molecular weight (Mw) of the epoxy crosslinking agent can be in the range of about 170 g / mol to about 100,000 g / mol, for example, in the range of about 170 g / mol to about 6,000 g / mol. Within the above range, the epoxy crosslinking agent can form a crosslinking bond with the polyurethane-based polymer to improve the adhesion strength.

[0059] In some example embodiments, the epoxy crosslinking agent can include at least one of ethylene glycol diglycidyl ether, bisphenol A novolac, cresol novolac, and phenol novolac.

[0060] The dry binder includes the polyurethane-based polymer and the epoxy crosslinking agent, and has an effect of improving the tensile strength and the adhesion strength by crosslinking, so that the polyurethane-based polymer and the epoxy crosslinking agent can be effectively used as the dry binder included in the positive electrode and the negative electrode for the rechargeable lithium battery.

[0061] Electrode Some example embodiments include an electrode for a rechargeable lithium battery including the dry binder according to the foregoing example embodiments and an electrode active material. The content of the dry binder is in the range of about 0.5 parts by weight to about 20 parts by weight, based on 100 parts by weight of the electrode active material.

[0062] The electrode can be manufactured by providing an electrode composition for a rechargeable lithium battery including the dry binder of the foregoing example embodiments and an electrode active material; coating the electrode composition on a current collector; and pressing the current collector.

[0063] The electrode can be a negative electrode or a positive electrode. The dry binder has a high adhesion strength and a low electrical resistance even when used in a negative electrode that undergoes a large volume change due to charging and discharging of a rechargeable lithium battery, and thus can contribute to improving the performance of the rechargeable lithium battery.

[0064] Hereinafter, a positive electrode and a negative electrode for a rechargeable lithium battery according to some example embodiments are described.

[0065] Negative electrode The negative electrode includes a current collector and a negative electrode active material layer on the current collector. The negative electrode active material layer includes a negative electrode active material, and can further include a binder and / or a conductive material. The binder can be or include the aforementioned example embodiments of the dry binder.

[0066] For example, the negative electrode active material layer can include about 90 wt% to about 99.5 wt% of the negative electrode active material, about 0.5 wt% to about 5 wt% of the binder, and about 0 wt% to about 5 wt% of the conductive material.

[0067] The negative electrode active material can include at least one of a material that reversibly intercalates / deintercalates lithium ions, lithium metal, a lithium metal alloy, a material capable of doping / de-doping lithium, and a transition metal oxide.

[0068] The material that reversibly intercalates / deintercalates lithium ions can include, for example, crystalline carbon, amorphous carbon, or a combination thereof as a carbon-based negative electrode active material. The crystalline carbon can be irregular or sheet, flake, spherical, or fibrous natural graphite or artificial graphite. The amorphous carbon can be or include at least one of soft carbon, hard carbon, meso-phase pitch carbonization product, calcined coke, etc.

[0069] The lithium metal alloy includes an alloy of lithium with a metal such as or including at least one of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn.

[0070] The material capable of doping / de-doping lithium can be or include a Si-based negative electrode active material or a Sn-based negative electrode active material. The Si-based negative electrode active material can include silicon, a silicon-carbon composite, SiO x (0 < x ≤ 2), a Si-Q alloy (where Q is or includes an element such as or including at least one of 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 combinations thereof), and combinations thereof. The Sn-based negative electrode active material can be or include at least one of Sn, SnO2, a Sn-based alloy, and combinations thereof.

[0071] The silicon-carbon composite can be or include a composite of silicon and amorphous carbon. According to some example embodiments, the silicon-carbon composite can be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles. For example, the silicon-carbon composite can include secondary particles (cores) in which silicon primary particles are assembled and an amorphous carbon coating layer (shell) on the surface of the secondary particles. Amorphous carbon can also exist between the silicon primary particles, for example, the silicon primary particles can be coated with amorphous carbon. The secondary particles can be dispersed in an amorphous carbon matrix.

[0072] The silicon-carbon composite can also include crystalline carbon. For example, the silicon-carbon composite can include a core including crystalline carbon and silicon particles and an amorphous carbon coating layer on the surface of the core.

[0073] The Si-based negative electrode active material or the Sn-based negative electrode active material can be mixed with the carbon-based negative electrode active material.

[0074] The binder causes the negative electrode active material particles to adhere to each other, and causes the negative electrode active material to adhere to the current collector. The binder can include an additional binder in addition to the dry binder according to some example embodiments. Examples of the additional binder can include at least one of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, an oxirane-containing polymer, polyvinylpyrrolidone, polyurethane, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, nylon, etc., but is not limited thereto.

[0075] The electrically conductive material is included to provide electrode conductivity, and any electrically conductive material can be used as the electrically conductive material, unless the electrically conductive material causes an adverse chemical change in the battery. Examples of the electrically conductive material include at least one of a carbon-based material such as natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, carbon nanofiber, carbon nanotube, etc.; a metal-based material including at least one of a metal powder or a metal fiber of copper, nickel, aluminum, silver, etc.; an electrically conductive polymer such as a polyaniline derivative; or a mixture thereof.

[0076] The negative electrode current collector can include at least one of a copper foil, a nickel foil, a stainless steel foil, a titanium foil, a nickel foam, a copper foam, a polymer substrate coated with an electrically conductive metal, and a combination thereof.

[0077] Positive electrode The positive electrode can include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer can include a positive electrode active material, and can also include a binder and / or an electrically conductive material. The binder can be or include the binder of the foregoing example embodiments.

[0078] The content of the positive electrode active material can be in the range of about 90 wt% to about 99.5 wt% or about 90 wt% to about 99.0 wt% based on 100 wt% of the positive electrode active material layer, and the content of each of the binder and the conductive material can be in the range of about 0.5 wt% to about 5 wt% based on 100 wt% of the positive electrode active material layer.

[0079] The positive electrode active material can be or include a compound capable of intercalating and deintercalating lithium (lithiated intercalation compound). For example, one or more types of composite oxides of lithium and a metal such as or including at least one of cobalt, manganese, nickel, and combinations thereof can be used.

[0080] The composite oxide can be or include a lithium transition metal composite oxide, and examples thereof can include at least one of lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate-based compounds, lithium nickel manganese-based oxides not containing cobalt, and combinations thereof.

[0081] As an example, a compound represented by any one of the following chemical formulas can be used. Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b 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 G e O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Lia 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 Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3(0≤f≤2); Li a FePO4(0.90≤a≤1.8).

[0082] In the above chemical formula, A is or includes at least one of Ni, Co, Mn, and combinations thereof; X is or includes at least one of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, and combinations thereof; D is or includes at least one of O, F, S, P, and combinations thereof; G is or includes at least one of Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, and combinations thereof; and L 1 is or includes at least one of Mn, Al, and combinations thereof.

[0083] The positive electrode active material can be or include at least one of, for example, a lithium nickel-based oxide represented by Chemical Formula 11, a lithium cobalt-based oxide represented by Chemical Formula 12, a lithium iron phosphate-based compound represented by Chemical Formula 13, a lithium nickel-manganese-based oxide not containing cobalt represented by Chemical Formula 14, and combinations thereof.

[0084] Chemical Formula 11: Li a1 Ni x1 M 1 y1 M 2 z1 O 2-b1 X b1 .

[0085] In Chemical Formula 11, 0.9≤a1≤1.8, 0.3≤x1≤1, 0≤y1≤0.7, 0≤z1≤0.7, 0.9≤x1+y1+z1≤1.1, and 0≤b1≤0.1, M 1 and M 2each independently is or includes one or more of Al, B, Ba, Ca, Ce, Co, Cr, Cu, Fe, Mg, Mn, Mo, Nb, Si, Sn, Sr, Ti, V, W, and Zr, and X is or includes at least one of F, P, and S.

[0086] In Chemical Formula 11, 0.6≤x1≤1, 0≤y1≤0.4, and 0≤z1≤0.4, or 0.8≤x1≤1, 0≤y1≤0.2, and 0≤z1≤0.2.

[0087] Chemical Formula 12: Li a2 Co x2 M 3 y2 O 2-b2 X b2 .

[0088] In Chemical Formula 12, 0.9≤a2≤1.8, 0.7≤x2≤1, 0≤y2≤0.3, 0.9≤x2+y2≤1.1, and 0≤b2≤0.1, M 3 is or includes at least one of Al, B, Ba, Ca, Ce, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Se, Si, Sn, Sr, Ti, V, W, Y, Zn, and Zr, and X is or includes at least one of F, P, and S.

[0089] Chemical Formula 13: Li a3 Fe x3 M 4 y3 PO 4-b3 X b3 .

[0090] In Chemical Formula 13, 0.9≤a3≤1.8, 0.6≤x3≤1, 0≤y3≤0.4, and 0≤b3≤0.1, M 4 is or includes at least one of Al, B, Ba, Ca, Ce, Co, Cr, Cu, Mg, Mn, Mo, Ni, Se, Si, Sn, Sr, Ti, V, W, Y, Zn, and Zr, and X is or includes at least one of F, P, and S.

[0091] Chemical Formula 14: Li a4 Ni x4 Mn y4 M 5 z4 O 2-b4 X b4 .

[0092] In Chemical Formula 14, 0.9 ≤ a4 ≤ 1.8, 0.8 ≤ x4 < 1, 0 < y4 ≤ 0.2, 0 ≤ z4 ≤ 0.2, 0.9 ≤ x4 + y4 + z4 ≤ 1.1, and 0 ≤ b4 ≤ 0.1, M 5 is or includes at least one of Al, B, Ba, Ca, Ce, Cr, Fe, Mg, Mo, Nb, Si, Sn, Sr, Ti, V, W, and Zr, and X is or includes at least one of F, P, and S.

[0093] For example, the positive electrode active material can be or include a high-nickel positive electrode active material, the nickel content in the high-nickel positive electrode active material being greater than or equal to about 80 mol%, greater than or equal to about 85 mol%, greater than or equal to about 90 mol%, greater than or equal to about 91 mol%, or greater than or equal to about 94 mol% and less than or equal to about 99 mol% based on 100 mol% of metals other than lithium in a lithium transition metal composite oxide. The high-nickel positive electrode active material can achieve a high capacity, and can be applied to a rechargeable lithium battery having a high capacity and a high density.

[0094] The aforementioned dry binder can be used as a positive electrode binder, and can further include other additional binders. The positive electrode binder improves the adhesion properties of the positive electrode active material particles to each other and to the current collector. As such additional binders, any binder commonly used in the art can be used without limitation. Examples of the additional binder can include at least one of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, an oxirane-containing polymer, polyvinyl pyrrolidone, polyurethane, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, and nylon, but are not limited thereto.

[0095] The electrically conductive material is included to provide electrode conductivity, and any electrically conductive material can be used as the electrically conductive material, unless the electrically conductive material causes a chemical change in the battery. Examples of the electrically conductive material can include at least one of carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, carbon nanofiber, carbon nanotube, or the like; metal-based materials including metal powder or metal fiber of at least one of copper, nickel, aluminum, silver, or the like; electrically conductive polymers such as polyaniline derivatives; or a mixture thereof.

[0096] The current collector can include Al, but is not limited thereto.

[0097] Electrolyte The electrolyte for the rechargeable lithium battery can be or include, for example, an electrolyte solution, which can include a non-aqueous organic solvent and a lithium salt.

[0098] The non-aqueous organic solvent constitutes a medium for transporting ions participating in electrochemical reactions of the battery. The non-aqueous organic solvent can be or include at least one of a carbonate-based solvent, an ester-based solvent, an ether-based solvent, a ketone-based solvent, an alcohol-based solvent, an aprotic solvent, and combinations thereof.

[0099] The carbonate-based solvent can include at least one of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), methyl ethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), or the like. The ester-based solvent can include at least one of methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanolide, methyl hydroxyvalerate, valerolactone, caprolactone, or the like. The ether-based solvent can include at least one of dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, or the like. In addition, the ketone-based solvent can include cyclohexanone or the like. The alcohol-based solvent can include ethanol, isopropyl alcohol, or the like. The aprotic solvent can include at least one of a nitrile such as R-CN (wherein R is a C2 to C20 linear, branched, or cyclic hydrocarbon group, and can include a double bond, an aromatic ring, or an ether group, etc.); an amide such as dimethylformamide; a dioxolane such as 1,3-dioxolane, 1,4-dioxolane, or the like; a sulfolane; or the like.

[0100] The non-aqueous organic solvent can be used alone, or in combination of two or more types of solvents, and when two or more types of solvents are used in combination, the mixing ratio can be appropriately adjusted according to the intended battery performance, which is widely understood by those skilled in the relevant art.

[0101] When the carbonate-based solvent is used, a cyclic carbonate and a chain carbonate can be mixed, and the cyclic carbonate and the chain carbonate can be mixed in a volume ratio ranging from about 1:1 to about 1:9.

[0102] The non-aqueous organic solvent can further include an aromatic hydrocarbon-based organic solvent. For example, the carbonate-based solvent and the aromatic hydrocarbon-based organic solvent can be mixed in a volume ratio ranging from about 1:1 to about 30:1.

[0103] The electrolyte solution can further include at least one of a vinyl ethylene carbonate compound, a vinylene carbonate compound, and an ethylene carbonate compound to improve the battery cycle life.

[0104] Representative examples of the ethylene carbonate compound can include at least one of fluoroethylene carbonate, difluoroethylene carbonate, chloroethylene carbonate, dichloroethylene carbonate, bromoethylene carbonate, dibromoethylene carbonate, nitroethylene carbonate, and cyanoethylene carbonate.

[0105] The lithium salt dissolved in the organic solvent supplies lithium ions in the battery, enables the rechargeable lithium battery to operate, and improves the transport of lithium ions between the positive electrode and the negative electrode. Examples of the lithium salt can include 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) (wherein x and y are integers of 1 to 20), lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluoro(oxalato)borate (LiDFOB), lithium difluorobis(oxalato)phosphate (LiDFBOP), and lithium bis(oxalato)borate (LiBOB).

[0106] The concentration of the lithium salt can be in the range of about 0.1 M to about 2.0 M. When the concentration of the lithium salt is in the above range, the electrolyte solution has a suitable ionic conductivity and viscosity, and thus desired or improved performance can be achieved and lithium ions can move effectively.

[0107] Separator Depending on the type of the rechargeable lithium battery, a separator can be present between the positive electrode and the negative electrode. The separator can include at least one of polyethylene, polypropylene, polyvinylidene fluoride, and a multi-layer film of two or more layers thereof (e.g., a mixed multi-layer film such as a polyethylene / polypropylene double-layer separator, a polyethylene / polypropylene / polyethylene triple-layer separator, a polypropylene / polyethylene / polypropylene triple-layer separator, etc.).

[0108] The separator can include a porous substrate and a coating layer including an organic material, an inorganic material, or a combination thereof on one surface or both surfaces of the porous substrate.

[0109] The porous substrate can be or include a polymeric film formed of or including any one of or a copolymer or mixture of two or more of at least one of polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyacetals, polyamides, polyimides, polycarbonates, polyether ketones, polyaryletherketones, polyether ether ketones, polyetherimides, polyamideimides, polybenzimidazoles, polyethersulfones, polyphenylene oxides, cyclic olefin copolymers, polyphenylene sulfides, polyethylene naphthalate, glass fibers, TEFLON, and polytetrafluoroethylene, or the like.

[0110] The porous substrate can have a thickness in a range of about 1 µm to about 40 µm, for example, in a range of about 1 µm to about 30 µm, about 1 µm to about 20 µm, about 5 µm to about 15 µm, or about 10 µm to about 15 µm.

[0111] The organic material can include a (meth)acrylic copolymer including a first structural unit derived from a (meth)acrylamide and a second structural unit including at least one of a structural unit derived from a (meth)acrylic acid or a (meth)acrylate and a structural unit derived from a (meth)acrylamide sulfonic acid or a salt thereof.

[0112] The inorganic material can include inorganic particles such as or including at least one of Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof, but is not limited thereto. The average particle diameter (D 50 ) of the inorganic particles can be in a range of about 1 nm to about 2000 nm, for example, in a range of about 100 nm to about 1000 nm or about 100 nm to about 700 nm.

[0113] The organic material and the inorganic material can be mixed in one coating layer, or a coating layer including the organic material and a coating layer including the inorganic material can be stacked together.

[0114] The thickness of the coating layer can be in a range of about 0.5 µm to about 20 µm, for example, in a range of about 1 µm to about 10 µm or about 1 µm to about 5 µm.

[0115] Rechargeable lithium battery The rechargeable lithium battery can be classified into a cylindrical battery, a prismatic battery, a pouch battery, a coin-type battery, or the like according to its shape. Figures 1 to 4To show a schematic view of a rechargeable lithium battery according to some example embodiments, wherein Figure 1 is a cylindrical battery, Figure 2 is a prismatic battery, and Figure 3 and Figure 4 is a pouch battery.

[0116] Referring to Figures 1 to 4 , the rechargeable lithium battery 100 can include an electrode assembly 40 having a separator 30 interposed between a positive electrode 10 and a negative electrode 20, the electrode assembly 40 being constructed in a case 50. The positive electrode 10, the negative electrode 20, and the separator 30 can be impregnated with an electrolyte solution (not shown). As shown in Figure 1 , the rechargeable lithium battery 100 can include a sealing member 60 sealing the case 50.

[0117] Further, in Figure 2 , the rechargeable lithium battery 100 can include a positive electrode lead tab 11, a positive electrode terminal 12 connected to the positive electrode lead tab 11, a negative electrode lead tab 21, and a negative electrode terminal 22 connected to the negative electrode lead tab 21. As shown in Figure 3 and Figure 4 , the rechargeable lithium battery 100 can include Figure 4 an electrode tab 70 as shown in Figure 3 or a positive electrode tab 71 and a negative electrode tab 72 as shown in , the electrode tab 70 / 71 / 72 forms an electrical path for conducting electric current formed in the electrode assembly 40 to the outside of the rechargeable lithium battery 100.

[0118] The following examples are described below. However, the following examples are only examples of the present disclosure, and the present disclosure is not limited to the following examples.

[0119] Example 1 Example 1-1: Preparation of dry binder Elastollan 11 produced by BASF as a polyurethane-based polymer including an ether group-containing structural unit and bisphenol A (EPICLON AM-020-P produced by DIC as a cross-linking agent were mixed in a weight ratio of 7:3 in a Thinky mixer at 2000 rpm for 3 minutes to prepare a cross-linked dry adhesive.

[0120] Example 1-2: Manufacture of negative electrode After the manufactured dry binder was pulverized, 3 wt% of the dry binder, 95 wt% of artificial graphite as the negative electrode active material, and 2 wt% of carbon black (Super P produced by Timcal) as the conductive material were mixed, and calendering treatment was performed at 1 rpm and 180°C to manufacture a sheet-shaped negative electrode active material layer. The negative electrode active material layer was pressed and attached to both sides of a copper current collector at 180°C to manufacture a negative electrode having a total of 250 μm thick negative electrode active material layer.

[0121] Example 1-3: Manufacture of battery cell A half-cell was manufactured using the negative electrode together with a lithium metal counter electrode and an electrolyte. The electrolyte was prepared by dissolving 1M LiPF6 in a mixed solvent of ethylene carbonate and diethyl carbonate at a volume ratio of 50:50.

[0122] Example 2 The dry binder, the negative electrode, and the battery cell were manufactured in the same manner as in Example 1, except that Elastollan 12 produced by BASF as a polyurethane-based polymer including an ether group-containing structural unit and bisphenol A (EPICLON AM-020-P produced by DIC) as a crosslinking agent were mixed at a weight ratio of 7:3 to prepare a crosslinked dry binder, and the thickness of the negative electrode active material layer was changed to 180 μm.

[0123] Example 3 The dry binder, the negative electrode, and the battery cell were manufactured in the same manner as in Example 1, except that Elastollan 800 produced by BASF as a polyurethane-based polymer including an ether group-containing structural unit and bisphenol A (EPICLON AM-020-P produced by DIC) as a crosslinking agent were mixed at a weight ratio of 6.5:3.5 to prepare a crosslinked dry binder, and the thickness of the negative electrode active material layer was changed to 200 μm.

[0124] Example 4 The dry binder, the negative electrode, and the battery cell were manufactured in the same manner as in Example 1, except that Elastollan 800 produced by BASF as a polyurethane-based polymer including an ether group-containing structural unit and phenol novolak-based crosslinking agent (EPICLON N-770 produced by DIC) were mixed at a weight ratio of 9:1 to prepare a crosslinked dry binder, and the thickness of the negative electrode active material layer was changed to 180 μm.

[0125] Example 5 A dry binder, a negative electrode, and a battery cell were manufactured in the same manner as in Example 1, except that Elastollan 800 produced by BASF and a cresol novolak type crosslinking agent (EPICLON N-665 produced by DIC) as a polyurethane-based polymer including an ether group-containing structural unit were mixed at a weight ratio of 8:2 to prepare a crosslinked dry binder, and the thickness of the negative electrode active material layer was changed to 220 μm.

[0126] Example 6 A dry binder, a negative electrode, and a battery cell were manufactured in the same manner as in Example 1, except that Elastollan 12 produced by BASF and a phenol novolak type crosslinking agent (EPICLON N-770 produced by DIC) as a polyurethane-based polymer including an ether group-containing structural unit were mixed at a weight ratio of 9:1 to prepare a crosslinked dry binder, and the thickness of the negative electrode active material layer was changed to 230 μm.

[0127] Example 7 A dry binder, a negative electrode, and a battery cell were manufactured in the same manner as in Example 1, except that Elastollan 11 produced by BASF and a cresol novolak type crosslinking agent (EPICLON N-665 produced by DIC) as a polyurethane-based polymer including an ether group-containing structural unit were mixed at a weight ratio of 8:2 to prepare a crosslinked dry binder, and the thickness of the negative electrode active material layer was changed to 200 μm.

[0128] Example 8 A dry binder, a negative electrode, and a battery cell were manufactured in the same manner as in Example 1, except that Elastollan 11 produced by BASF and ethylene glycol diglycidyl ether (Sigma Aldrich Corporation) as a crosslinking agent as a polyurethane-based polymer including an ether group-containing structural unit were mixed at a weight ratio of 9:1 to prepare a crosslinked dry binder, and the thickness of the negative electrode active material layer was changed to 260 μm.

[0129] Comparative Example 1 A dry binder, a negative electrode, and a battery cell were manufactured in the same manner as in Example 1, except that only Elastollan 11 produced by BASF was used as a polyurethane-based polymer including an ether group-containing structural unit to prepare a dry binder, and the thickness of the negative electrode active material layer was changed to 150 μm.

[0130] Comparative Example 2 A dry binder, a negative electrode, and a battery cell were manufactured in the same manner as in Example 1, except that only a phenol novolak-based dry binder (EPICLON N-770 produced by DIC) was used to prepare the dry binder, and the thickness of the negative electrode active material layer was changed to 100 μm.

[0131] Comparative Example 3 A negative electrode and a battery cell were manufactured in the same manner as in Example 1, except that Elastollan 11 produced by BASF and a phenol novolak-based cross-linking agent (EPICLON N-770 produced by DIC) as a polyurethane-based polymer including an ether group-containing structural unit were mixed in an NMP solvent at a weight ratio of 7:3 to prepare a cross-linked wet binder, and the thickness of the negative electrode active material layer was changed to 220 μm.

[0132] Comparative Example 4-1 A negative electrode and a battery cell were manufactured in the same manner as in Example 1, except that a PTFE binder (DF 681F produced by Syensqo) was used as a dry binder, and the thickness of the negative electrode active material layer was changed to 220 μm.

[0133] Comparative Example 4-2 A negative electrode and a battery cell were manufactured in the same manner as in Comparative Example 4-1, except that the negative electrode active material layer was pressed together with a copper current collector in which an adhesion primer layer composed of a PVDF binder and carbon black (Spuer P produced by Timcal) as a conductive material was additionally formed.

[0134] Evaluation Example 1: Tensile strength and adhesive strength The tensile strength of the sheet-shaped negative electrode active material layer according to Examples 1 to 8 and Comparative Examples 1 to 4-1 was measured by a universal testing machine (UTM) tensile strength tester, and the results are shown in Table 1 below.

[0135] Evaluation Criteria: When the tensile strength was greater than 1.5 N, a was given, when the tensile strength was in a range of greater than 1.0 N and less than or equal to 1.5 N, an was given, and when the tensile strength was less than or equal to 1.0 N, an X was given.

[0136] Subsequently, the adhesion strength between the current collector and the negative electrode active material layer of the negative electrode according to Examples 1 to 8 and Comparative Examples 1 to 4-1 was measured by using a UTM tensile strength tester. Here, each sample was prepared by attaching a glass slide to one side of a double-sided tape, and then attaching each negative electrode to the other side of the double-sided tape. The sample was mounted on the UTM tensile strength tester to measure the adhesion strength by peeling the negative electrode from the glass slide to a peeling angle of 180°, and the results are shown in Table 1 below.

[0137] Evaluation Criteria: When the measured value was 0.8 gf / mm or less, X was given, when the measured value was 0.8 gf / mm to 1.0 gf / mm, O was given, and when the measured value was more than 1.0 gf / mm, was given.

[0138] Table 1:

[0139] Referring to Table 1, Comparative Example 1 using a binder including no epoxy crosslinking agent but only a polyurethane-based polymer exhibited deteriorated tensile strength and adhesion strength. In Comparative Example 2 using only an epoxy crosslinking agent as a binder, the flexibility of the electrode plate was reduced, causing a crack and making it difficult to form an electrode, as a result of which it was impossible to measure the tensile strength and the adhesion strength. Comparative Example 3 performing a wet process by adding a polyurethane-based polymer and an epoxy crosslinking agent to a solvent exhibited slightly deteriorated tensile strength and adhesion strength. Comparative Example 4-1 using a PTFE binder exhibited deteriorated adhesion strength.

[0140] On the contrary, Examples 1 to 8 using a mixed binder of a polyurethane-based polymer and an epoxy crosslinking agent exhibited improved adhesion strength and tensile strength through a crosslinking reaction between the polyurethane-based polymer and the epoxy crosslinking agent.

[0141] Evaluation Example 2: Evaluation of storage stability of binder The binder in a powder state according to Examples 1 to 8 and Comparative Examples 1, 2, and 4-1 was mixed at 2000 rpm in a Thinky mixer, respectively, compared to the slurry of Comparative Example 3, to evaluate whether an electrode could be formed just after mixing and after 3 days, and the storage stability results are shown in Table 2 below.

[0142] Evaluation Criteria: When an electrode could be formed, O was given, and when an electrode could not be formed, X was given.

[0143] Table 2:

[0144] Referring to Table 2, for Examples 1 to 8, the electrode could be formed immediately after mixing or after 3 days. However, in Comparative Example 2 in which the epoxy crosslinking agent was used alone, the flexibility of the electrode plate was low, cracks were induced, and it was difficult to form the electrode. In Comparative Example 3, the electrode could be formed immediately after mixing, but after 3 days of mixing, the electrode could not be formed due to a sharp increase in viscosity. Thus, for long-term storage of the mixture containing the epoxy crosslinking agent, it is advantageous to use a dry binder mixed with powder.

[0145] Evaluation Example 3: Electrolyte solution stability The electrolyte solution stability was measured by immersing the negative electrodes of Examples 1 to 8 and Comparative Examples 1 to 4-2 in an electrolyte solution to check whether peeling occurred after 3 days at 60°C, and the results are shown in Table 3 below.

[0146] Evaluation Criteria: The electrolyte solution stability was evaluated by giving X to peeling, which was used as a criterion. Even when peeling was not observed, but when it could be pushed by hand after evaluation, O was given. When neither peeling nor pushing was possible, X was given.

[0147] Table 3:

[0148] Referring to Table 3, when the polyurethane-based polymer of Comparative Example 1 was used alone as the binder, the electrolyte stability was deteriorated. In Examples 1 to 8, the epoxy crosslinking agent reduced the swelling property, thereby improving the electrolyte solution safety.

[0149] Evaluation Example 4: Current density and initial charge / discharge efficiency The half-cells of Examples 1 to 8 and Comparative Examples 1 to 4-2 were charged at a constant current of 0.5 C to a voltage of 4.25 V, and cut off in a constant voltage mode of 4.25 V at a current rate of 0.02 C. Subsequently, the cells were discharged at a constant current of 0.5 C to a voltage of 2.8 V.

[0150] Evaluation Criteria: If the current density was 4 mA / cm 2 or less, X was given, if the current density was greater than 4 mA / cm 2 and less than or equal to 5 mA / cm 2 , O was given, and if the current density was greater than 5 mA / cm 2 , X was given.

[0151] If the initial charge / discharge efficiency is 90% or more, then a is given, if the initial charge / discharge efficiency is greater than or equal to 87% and less than 90%, then a is given, if the initial charge / discharge efficiency is greater than or equal to 84% and less than 87%, then a is given, and if the initial charge / discharge efficiency is less than 84%, then X is given.

[0152] Table 4:

[0153] Referring to Table 4 above, the half-cells of Examples 1 to 8 in which the negative electrode has a relatively high dielectric constant exhibited high current density and initial charge / discharge efficiency.

[0154] In contrast, in the half-cell of Comparative Example 1 which does not have a crosslinking agent and the half-cell of Comparative Example 3 which includes a wet binder, a caking phenomenon occurred, resulting in high resistance. This resulted in a decrease in battery performance, with low current density and initial charge / discharge efficiency. In addition, the half-cell of Comparative Example 4-2 exhibited high current density, but exhibited low initial charge / discharge efficiency due to the low reduction stability of the negative electrode.

[0155] While the present disclosure has been described in connection with what is presently considered to be the practical example embodiments, it is to be understood that the disclosure is not limited to the disclosed example embodiments. On the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0156] Explanation of symbols: 100: rechargeable lithium battery; 10: positive electrode 11: positive electrode lead tab; 12: positive electrode terminal 20: negative electrode; 21: negative electrode lead tab 22: negative electrode terminal; 30: separator 40: electrode assembly; 50: case 60: sealing member; 70: electrode tab 71: positive electrode tab; 72: negative electrode tab.

Claims

1. A dry adhesive, said dry adhesive comprising: Crosslinking products of polyurethane polymers through epoxy crosslinking agents.

2. The dry adhesive according to claim 1, wherein, Based on 100 parts by weight of the dry adhesive, the content of the polyurethane polymer is in the range of 60 parts by weight to 95 parts by weight.

3. The dry adhesive according to claim 1, wherein, Based on 100 parts by weight of the dry adhesive, the content of the epoxy crosslinking agent is in the range of 5 parts by weight to 40 parts by weight.

4. The dry adhesive according to claim 1, wherein, The polyurethane polymer comprises structural units represented by chemical formula 1: Chemical Formula 1: ； In chemical formula 1, R 1 Includes a linking group, which is independently at least one of substituted or unsubstituted C1 to C20 alkylene, substituted or unsubstituted C3 to C20 cycloalkylene, and combinations thereof. n is an integer in the range of 1 to 300, and Indicates the connection point with the main chain.

5. The dry adhesive according to claim 1, wherein, The polyurethane polymer includes at least one structural unit represented by chemical formula 1-1, chemical formula 1-2, and chemical formula 1-3: Chemical formula 1-1: ； Chemical formulas 1-2: ； Chemical formulas 1-3: ； Among them, in chemical formulas 1-1, 1-2, and 1-3, R 1 R 3 R 4 and R 5 Each component independently includes a linking group, said linking group comprising at least one of substituted or unsubstituted C1 to C20 alkylene groups, substituted or unsubstituted C3 to C20 cycloalkylene groups, and combinations thereof. x, y, and z are the mole fractions of each structural unit and are each independently in the range of 0 to 1. n is an integer in the range of 1 to 200, and This indicates the connection point with the main chain.

6. The dry adhesive according to claim 5, wherein, The substituted or unsubstituted C1 to C20 alkylene groups include -(CH2). n - is a structural unit, where n is an integer in the range of 1 to 14.

7. The dry adhesive according to claim 6, wherein, At least one non-adjacent methylene group represented by -(CH2)- among the substituted or unsubstituted C1 to C20 alkylene groups is replaced by at least one of -NH-, -C(=O)-, and combinations thereof.

8. The dry adhesive according to claim 1, wherein, The epoxy crosslinking agent includes at least one of the compounds represented by chemical formulas 2-1, 2-2, 2-3, 2-4, and 2-5: Chemical formula 2-1: ； Chemical formula 2-2: ； Chemical formula 2-3: ； Chemical formula 2-4: ； Chemical formula 2-5: ； Among them, in chemical formulas 2-1, 2-2, 2-3, 2-4, and 2-5, R 6 R 10 and R 11 Each independently comprises substituted or unsubstituted C1 to C6 alkylene groups, R 7 R 8 and R 9 The same or different and each independently includes hydrogen, deuterium or substituted or unsubstituted C1 to C6 alkyl groups, n is an integer greater than or equal to 1 and less than or equal to 30, and a, b and c are each independently an integer greater than or equal to 0 and less than or equal to 4.

9. The dry adhesive according to claim 1, wherein, The weight-average molecular weight of the polyurethane polymer is in the range of 600 g / mol to 800,000 g / mol.

10. The dry adhesive according to claim 1, wherein, The weight-average molecular weight of the epoxy crosslinking agent is in the range of 170 g / mol to 6,000 g / mol.

11. An electrode for a rechargeable lithium battery, the electrode comprising: The dry adhesive according to any one of claims 1 to 10; as well as Electrode active material.

12. The electrode according to claim 11, wherein, Based on 100 parts by weight of the electrode active material, the content of the dry binder is in the range of 0.5 parts by weight to 20 parts by weight.

13. The electrode according to claim 11, wherein, The electrode is a negative electrode.

14. The electrode according to claim 13, wherein, The negative electrode includes a negative electrode active material, which includes at least one of carbon-based negative electrode active materials, silicon-based negative electrode active materials, and combinations thereof.

15. The electrode according to claim 11, wherein, The electrode is a positive electrode.

16. A rechargeable lithium battery, said rechargeable lithium battery comprising: Positive electrode; negative electrode; as well as Electrolytes, Wherein, at least one of the negative electrode and the positive electrode comprises the dry binder according to any one of claims 1 to 10.

17. A method for manufacturing an electrode, the method comprising the following steps: Electrode active material, binder and conductive material are mixed in a dry manner to prepare a composition for forming electrodes; as well as The composition for forming the electrode is coated onto the electrode current collector to form the electrode. The adhesive includes a crosslinking reaction product of a polyurethane polymer crosslinked by an epoxy crosslinking agent.

18. The method according to claim 17, wherein, The electrode is formed by a rolling process.

Images