Binder for negative electrode of rechargeable lithium battery and rechargeable lithium battery including same

Abstract

A binder for a negative electrode of a rechargeable lithium battery and a rechargeable lithium battery including the same are provided. The binder includes a copolymer configured from a unit derived from an aromatic vinyl-based monomer, a unit derived from a (meth) acrylate-based monomer, and a unit derived from a triene-based monomer.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0134923 filed in the Korean Intellectual Property Office on October 11, 2023, the entire contents of which are incorporated herein by reference. Technical Field

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

[0003] In response to the recent rapid popularization of electronic devices (such as mobile phones, laptop computers, electric vehicles, etc.) using rechargeable lithium batteries (or lithium secondary batteries), the demand for secondary batteries with relatively high energy density and high capacity is rapidly increasing. Therefore, research and development to improve the performance of lithium secondary batteries is actively being carried out.

[0004] A rechargeable lithium battery is a battery including a positive electrode and a negative electrode including an active material capable of inserting and extracting lithium ions. The battery includes an electrolyte, and if (for example, when) lithium ions are inserted / extracted into / from the positive electrode and the negative electrode, electric energy is generated through oxidation and reduction reactions.

[0005] A negative electrode for a rechargeable lithium battery is required (or desired) to have low electrode plate resistance and high adhesion of a negative electrode active material layer to a current collector. Summary of the invention

[0006] One or more aspects relate to a binder for a negative electrode of a rechargeable lithium battery, which realizes a negative electrode active material layer having low negative plate resistance and high adhesion (adhesion) to a current collector.

[0007] One or more aspects relate to a negative electrode for a rechargeable lithium battery and a rechargeable lithium battery including the negative electrode, the negative electrode including the binder described herein.

[0008] One or more aspects relate to a binder for a negative electrode of a rechargeable lithium battery, the binder including a unit derived from an aromatic vinyl-based monomer, a unit derived from a (meth)acrylate-based monomer, and a unit derived from a triene-based monomer.

[0009] One or more aspects relate to a negative electrode for a rechargeable lithium battery, the negative electrode including the binder described herein.

[0010] One or more aspects relate to a rechargeable lithium battery including the negative electrode for a rechargeable lithium battery described herein, a positive electrode, and an electrolyte.

[0011] One or more aspects relate to a binder for a negative electrode of a rechargeable lithium battery, which can provide a negative electrode active material layer having low negative plate resistance and high adhesion to a current collector.

[0012] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosed present embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The foregoing and other objects, features and advantages of the present disclosure will become more apparent to those skilled in the art by describing in more detail exemplary embodiments of the present disclosure with reference to the accompanying drawings. In the accompanying drawings: Figures 1 to 4 are each a schematic diagram of a rechargeable lithium battery according to one or more embodiments; and Figure 5 A method of measuring adhesion force regarding Experimental Example 2 is shown. DETAILED DESCRIPTION

[0014] In order to fully understand the construction and effects of the present disclosure, the exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings, and those skilled in the art can easily practice the exemplary embodiments of the present disclosure. However, it should be noted that this is provided by way of example, the present disclosure is not limited thereto, and is only limited by the scope of the claims described in more detail herein. On the contrary, the exemplary embodiments are provided only to disclose the present disclosure and to enable those skilled in the art to fully understand the scope of the present disclosure.

[0015] In the drawings, the thickness of layers, films, panels, regions, etc. are exaggerated for clarity, and the same reference numerals always represent the same elements, and repeated descriptions thereof may not be provided in the specification. Unless otherwise specified in the specification, if (for example, when) a part of a layer, film, region, panel, etc. is referred to as being "on" another part, this includes not only the case where the part is "directly on" the other part, but also the case where other parts are interposed therebetween.

[0016] Unless otherwise specified in the specification, a singular expression may include a plural expression. In addition, unless otherwise specified, "A or B" may mean "including A, including B, or including A and B".

[0017] In the specification, "a combination thereof (or a combination thereof)" may refer to a mixture, a laminate, a composite, a copolymer, an alloy, a blend, and a reaction product of the components.

[0018] As used in this specification, the terms "include", "comprising", "having" and their variations 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 thereof. However, the use of these terms does not prevent or exclude the possibility of the presence or addition of one or more other components, features, quantities, steps (e.g., actions or tasks), elements and / or their (e.g., any suitable) combinations thereof.

[0019] In one or more embodiments, the term “layer” herein includes not only a shape formed or disposed on the entire surface if (for example, when) viewed from a plan view, but also a shape formed or disposed on a partial surface.

[0020] 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 parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings set forth herein, the first element, first component, first region, first layer or first part described herein may be referred to as the second element, second component, second region, second layer or second part.

[0021] As used herein, the term "and / or" includes any 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 if (for example, when) before / after a list of elements, rather than modifying 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 refer to only a, only b, only c, (for example, simultaneously) both a and b, (for example, simultaneously) both a and c, (for example, simultaneously) both b and c, all of a, b, and c, or variations thereof.

[0022] Spatially relative terms such as "under...", "below...", "below (lower part)", "above...", "above (upper part)", 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 spatially relative terms are intended to cover different orientations of the device in use or operation in addition to the orientation shown in the drawings. For example, if (for example, when) the device in the drawings is turned over, the elements described as "under" or "below" other elements or features will be oriented as "above" the other elements or features. Therefore, the example term "under..." can (for example, simultaneously) cover both the above and below orientations. The device can be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative terms used herein can be interpreted accordingly.

[0023] Unless otherwise defined, all terms used herein (including chemical terms, technical terms, and scientific terms) have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It will also be understood that terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense.

[0024] Example embodiments are described herein with reference to cross-sectional views which are schematic diagrams of idealized embodiments. As such, variations in the shapes of the illustrations due to, for example, manufacturing techniques and / or tolerances are to be expected. Therefore, the embodiments described herein should not be construed as limited to the specific shapes of the regions as shown herein, but rather include shape deviations due to, for example, manufacturing. For example, a region shown or described as flat may typically have rough and / or nonlinear features. In addition, the sharp corners shown may be rounded. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the precise shape of the regions, and are not intended to limit the scope of the claims presented.

[0025] 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 including the corresponding listed items. Descriptions of features or aspects within each embodiment should generally be considered available for other similar features or aspects in other embodiments.

[0026] In this context, "consisting essentially of" means that any additional components will not substantially affect the chemical, physical, optical, or electrical properties of the semiconductor film.

[0027] Furthermore, in this specification, the phrase "on a plane" or "plan view" means observing a target portion from the top, and the phrase "on a cross section" means observing a cross section formed by vertically cutting the target portion from the side.

[0028] In the context of the present application and unless defined otherwise, the term "use" and variations thereof may be considered synonymous with the term "utilize" and variations thereof, respectively.

[0029] Unless otherwise defined in the specification, the particle size may be an average particle size. In addition, the particle size refers to the average particle size (D50) corresponding to the cumulative volume of 50 vol% in the particle size distribution. The average particle size (D50) can be measured by a method widely suitable in the art, for example, using a particle size analyzer, a transmission electron microscope image, or a scanning electron microscope image. As another method, the average particle size (D50) can be measured by using a measuring instrument using a dynamic light scattering method, analyzing the data to count the number of particles in each particle size range, and calculating the average particle size from the result. In one or more embodiments, the laser diffraction method can be used for measurement. For example, if (for example, when) the laser diffraction method is used for measurement, the particles to be measured are dispersed in a dispersion medium, and then a commercially available laser diffraction particle size measuring instrument (for example, MT 3000 commercially available from MicRotRac) is used at an output of 60W with ultrasound irradiation having a frequency of about 28 kHz, and the average particle size (D50) corresponding to 50% in the particle size distribution in the measuring instrument is calculated.

[0030] In the specification, "(meth)acrylic acid" means acrylic acid and / or methacrylic acid.

[0031] In the specification, if (for example, when) a numerical range is described, the expression “X to Y” means “X or more and Y or less (≥X, and ≤Y)”.

[0032] Binders for negative electrodes of rechargeable lithium batteries A binder for a negative electrode of a rechargeable lithium battery according to one or more embodiments includes a unit derived from an aromatic vinyl-based monomer, a unit derived from a (meth)acrylate-based monomer, and a unit derived from a triene-based monomer.

[0033] If (for example, when) applied to a negative electrode active material layer, a binder comprising units derived from an aromatic vinyl monomer and units derived from a (meth) acrylate monomer can reduce the negative electrode plate resistance. However, the negative electrode active material layer comprising the binder will have low adhesion to the current collector. In some embodiments, a negative electrode comprising a negative electrode active material layer having high adhesion to the current collector is advantageous. For example, a negative electrode comprising a negative electrode active material layer having high adhesion can increase the reliability of a rechargeable lithium battery.

[0034] The unit derived from the triene-based monomer can realize a negative electrode active material layer having high adhesion to a current collector through a binder while maintaining low negative electrode plate resistance.

[0035] The triene monomer may be a compound (e.g., an organic small molecule) having three double bonds in one monomer. If (e.g., when) the monomer is copolymerized with an aromatic vinyl monomer and a (meth) acrylate monomer, one or two double bonds remaining unpolymerized may exist in a free state (e.g., unreacted form). The double bonds existing in a free state (e.g., unreacted form) may be used to (e.g., expected to) increase the adhesion of the negative electrode active material layer to the current collector (e.g., copper atoms of a copper current collector) by allowing additional (e.g., molecular scale) interactions with the current collector. However, without being bound by any particular theory, it is believed that the increase in adhesion achieved by the binder according to one or more embodiments described herein is not limited thereto.

[0036] In one or more embodiments, the binder may be a (meth)acrylic copolymer of a monomer mixture (eg, a monomer mixture including an aromatic vinyl-based monomer, a (meth)acrylic ester-based monomer, and a triene-based monomer).

[0037] In one or more embodiments, the triene monomer may (e.g., needs to) be included in an appropriate or suitable content (e.g., amount) range relative to the total amount of the aromatic vinyl monomer and the (meth) acrylic acid ester monomer. Therefore, the adhesion to the current collector can be increased without affecting the aspect of reducing the negative plate resistance of the units derived from the aromatic vinyl monomer and the units derived from the (meth) acrylic acid ester monomer. For example, relative to the total amount (100 parts by weight) of the aromatic vinyl monomer and the (meth) acrylic acid ester monomer, the content of the triene monomer can be about 1 part by weight to about 100 parts by weight, for example, about 1 part by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight or 90 parts by weight, for example, about 1 part by weight to about 90 parts by weight, about 5 parts by weight to about 60 parts by weight, about 10 parts by weight to about 60 parts by weight, or about 1 part by weight to about 50 parts by weight. Within the range, the adhesion improvement produced by adding the triene monomer to the combination of the aromatic vinyl monomer and the (meth) acrylic acid ester monomer can be obtained or achieved.

[0038] In one or more embodiments, the triene monomer may be included in the monomer mixture in an amount of about 3 wt % to about 45 wt % relative to the total amount of the monomer mixture. Within the range, if (for example, when) the triene monomer is copolymerized with the aromatic vinyl monomer and the (meth) acrylate monomer, significant aspects of reducing negative plate resistance and increasing adhesion may be obtained or achieved, and the function of the negative electrode may not be affected (or substantially affected). For example, relative to the total amount of the monomer mixture, the content of the triene monomer can be about 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt%, 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, or 45wt%, for example, about 5wt% to about 45wt%, about 15wt% to about 40wt%, about 10wt% to about 30wt%, about 5wt% to about 35wt%, or about 5wt% to about 25wt%. Within the range, the negative electrode plate resistance can be significantly reduced, and the adhesion force can also be significantly increased.

[0039] In one or more embodiments, the monomer mixture may exclude (e.g., substantially free of) diene monomers. The binder may exclude (e.g., substantially free of any) units derived from diene monomers. Here, "diene monomers" may be monomers having two double bonds in one monomer, and suitable typical types or types of diene monomers in the art may be used. For example, the diene monomer may be a C4 to C10 diene monomer, and, for example, may be butadiene. Here, "substantially free of" means that the content of the diene monomer in the monomer mixture may be about 0.1wt% or less, for example, 0wt% to about 0.1wt%, or 0wt%, and relative to the total amount (100wt%) of the binder, the content of the unit derived from the diene monomer may be about 0.1wt% or less, for example, 0wt% to about 0.1wt%, or 0wt%.

[0040] In one or more embodiments, the total amount of the aromatic vinyl monomer, the (meth)acrylate monomer, and the triene monomer may be about 99.5 wt % or more, for example, about 99.8 to about 100 wt %, for example, 100 wt %, relative to the total amount of the monomer mixture.

[0041] Hereinafter, the aforementioned monomers will be described in more detail.

[0042] The triene-based monomer may be a monomer having three double bonds in the monomer, and may be, for example, a monomer having a structure of Chemical Formula 1.

[0043] Chemical formula 1

[0044] In Chemical Formula 1, R1, R2, R3, R4, R5, R6, R7 and R8 may each independently be hydrogen or a C1 to C5 alkyl group, X and Z may each independently be a single bond or a C1 to C5 alkylene group, M and N may each independently be 0 or 1, and M+N may be 1.

[0045] In Chemical Formula 1, “single bond” refers to a bond between carbon atoms (C and C) directly connected.

[0046] In one or more embodiments, R1, R2, R3, R4, R5, R6, R7 and R8 may each independently be hydrogen or a C1 to C3 alkyl group, for example, hydrogen or methyl.

[0047] In one or more embodiments, R1 and R2 may each independently be a C1 to C5 alkyl group, for example, a C1 to C3 alkyl group, for example, a methyl group. The compound of Formula 1 in which R1 and R2 are connected to a carbon atom having a double bond (for example, connected to another carbon atom) may allow the side chain of the binder to branch to achieve additional interaction with the current collector, and thus may increase adhesion to the current collector.

[0048] In one or more embodiments, X and Z may each independently be a single bond or a C1 to C3 alkylene group, for example, a methylene group, an ethylene group, or a propylene group.

[0049] For example, the compound of Chemical Formula 1 may include at least one (eg, one or more) selected from the group consisting of myrcene (Chemical Formula 1-1), ocimene (Chemical Formula 1-2), and alloocimene (Chemical Formula 1-3): Chemical formula 1-1

[0050] Chemical formula 1-2

[0051] Chemical formula 1-3 .

[0052] The (meth)acrylate-based monomer may reduce the negative electrode plate resistance of the binder by being included in the monomer mixture.

[0053] The (meth)acrylate monomer may be a (meth)acrylate having an ester portion and having a substituted or unsubstituted straight or branched C1 to C20 alkyl group at the ester portion. For example, the (meth)acrylate monomer may be 2-ethylhexyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, isobornyl acrylate, isovinyl acrylate, isovinyl methacrylate, and / or (e.g., any suitable) combination thereof.

[0054] In one or more embodiments, the (meth)acrylate monomer may be a (meth)acrylate having an unsubstituted linear or branched C1 to C20 alkyl group, for example, a (meth)acrylate having an unsubstituted linear or branched C1 to C10 alkyl group or a C1 to C5 alkyl group.

[0055] In one or more embodiments, the (meth)acrylate-based monomer may be a (meth)acrylate having a linear or branched C1 to C20 alkyl group (eg, a linear or branched C1 to C10 alkyl group or a C1 to C5 alkyl group) and substituted with one or more hydroxyl groups.

[0056] The content of the (meth)acrylate monomer may be about 5 wt % to about 45 wt % relative to the total amount of the monomer mixture. Within the described range, the aspect of reducing the resistance of the electrode plate may be obtained or achieved, and the appropriate or suitable amount of the (meth)acrylate monomer may prevent or reduce the reduction of adhesion to the current collector. For example, relative to the total amount of the monomer mixture, the content of the monomer can be about 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt%, 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt% or 45wt%, for example, about 5wt% to about 35wt% or about 10wt% to about 35wt%.

[0057] The aromatic vinyl-based monomer may be a substituted or unsubstituted styrene-based monomer, and may be styrene, α-methylstyrene, β-methylstyrene, p-tert-butylstyrene, chlorostyrene, and / or (eg, any suitable) combinations thereof.

[0058] Relative to the total amount of the monomer mixture, the content of the aromatic vinyl monomer can be about 10wt% to about 90wt%. Within the range, a hard domain for imparting elasticity to the binder can be formed. For example, relative to the total amount of the monomer mixture, the content of the monomer can be about 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 85wt% or 90wt%, for example, about 30wt% to about 70wt%, for example, about 40wt% to about 60wt%.

[0059] According to one or more embodiments, the binder may be an aqueous binder. Therefore, the binder may be appropriately or suitably applied to the negative electrode, but the present disclosure is not limited thereto.

[0060] The binder according to one or more embodiments can be prepared by polymerizing a monomer mixture through a suitable typical method in the art. The polymerization process can be emulsion polymerization, suspension polymerization, solution polymerization, etc.

[0061] Emulsion polymerization can be carried out in the presence of an emulsifier. The emulsifier can be an alkali metal salt of a higher fatty acid, a salt of N-acrylic amino acid, an alkyl ether carbonate, an acylated peptide, an alkyl sulfonate, an alkyl benzene sulfonate, a salt of an alkyl amino acid, an alkyl naphthalene sulfonate, a sulfosuccinate, a sulfonated oil, an alkyl sulfate, an alkyl ether sulfate, an alkyl aryl ether sulfate, an alkyl amide sulfate, an alkyl phosphate, an alkyl ether phosphate, an alkyl aryl ether phosphate and / or its (for example, any suitable) combination. For example, the emulsifier can be sodium dodecylbenzene sulfonate. In certain embodiments, the alkyl group of the emulsifier can be a C1 to C20 alkyl group.

[0062] The initiator may be an azo compound initiator such as azoisobutyronitrile, ammonium persulfate, potassium persulfate, hydrogen peroxide, tert-butyl hydroperoxide, and / or (eg, any suitable) combinations thereof.

[0063] The content of the emulsifier may be about 0.1 parts by weight to about 3 parts by weight, for example, about 0.1 parts by weight to about 2 parts by weight, relative to the total content (e.g., amount) of the monomer mixture (100 parts by weight). If (e.g., when) the content (e.g., amount) of the emulsifier falls within the range, adhesion may be improved, and a binder having a size more suitable for promoting dispersion may be obtained.

[0064] The initiator may be included in an amount of about 0.1 parts by weight to about 3 parts by weight, for example, about 0.1 parts by weight to about 2 parts by weight, relative to the total content (eg, amount) of the monomer mixture (100 parts by weight).

[0065] The binder may have an average particle size (D50) of about 10 nanometers (nm) to about 500 nm, for example, about 50 nm to about 300 nm (for example, may be in the form of particles having an average particle size (D50) of about 10 nanometers (nm) to about 500 nm, for example, about 50 nm to about 300 nm). Within the range, a negative electrode that appropriately or suitably ensures its processability may be manufactured. In this specification, when the particle is spherical, "diameter" means the average particle size, and when the particle is non-spherical, "diameter" means the length of the major axis.

[0066] Negative electrode for rechargeable lithium battery The negative electrode for a rechargeable lithium battery may include a current collector and a negative electrode active material layer disposed on the current collector, and the negative electrode active material layer may include a binder for the negative electrode of the rechargeable lithium battery described herein. The negative electrode active material layer may further include a negative electrode active material. The negative electrode active material layer may further include a conductive material. In addition to the binder for the negative electrode of the rechargeable lithium battery described herein, the negative electrode active material layer may further include other binders.

[0067] For example, the negative electrode active material layer may include from about 90 wt% to about 99 wt% of a negative electrode active material, from about 0.5 wt% to about 5 wt% of a binder, and from about 0 wt% to about 5 wt%, for example, from about 0.5 wt% to about 5 wt% of a conductive material.

[0068] The negative electrode active material may include a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, a lithium metal alloy, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0069] As a material capable of reversibly intercalating / deintercalating lithium ions, a carbon-based negative electrode active material may be used, for example, crystalline carbon, amorphous carbon, and / or a combination thereof (e.g., any suitable combination). Examples of crystalline carbon include amorphous, plate-like, flaky, spherical, or fibrous natural graphite or artificial graphite, and examples of amorphous carbon include soft carbon, hard carbon, mesophase pitch carbide, and / or calcined coke, etc.

[0070] As a lithium metal alloy, 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 may be used.

[0071] As a material capable of doping and dedoping lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. The Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiO x (0 < x < 2), a Si-Q alloy (where Q is selected from alkali metals, alkaline earth metals, group 13 elements, group 14 elements (excluding Si), group 15 elements, group 16 elements, transition metals, rare earth elements, and / or a combination thereof (e.g., any suitable combination)), and / or a combination thereof (e.g., any suitable combination). The Sn-based negative electrode active material may be Sn, SnO2, SnO x (0 < x < 2), a Sn-based alloy, and / or a combination thereof (e.g., any suitable combination).

[0072] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one or more embodiments, the silicon-carbon composite may be in the form of silicon particles (primary silicon particles) coated with amorphous carbon. For example, the silicon-carbon composite may include secondary particles (cores) formed by aggregating primary silicon particles and an amorphous carbon coating layer (shell) arranged on the surface of the secondary particles. Amorphous carbon may also be arranged between primary silicon particles, so that the primary silicon particles may be coated with amorphous carbon. The secondary particles may be present in the amorphous carbon matrix in a dispersed state.

[0073] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles (primary silicon particles) and an amorphous carbon coating layer disposed on a surface of the core.

[0074] The Si-based negative electrode active material or the Sn-based negative electrode active material may be used in combination with the carbon-based negative electrode active material.

[0075] According to one or more embodiments, the negative electrode may include only a binder for a negative electrode of a rechargeable lithium battery as a binder.

[0076] According to one or more embodiments, in addition to the binder for the negative electrode of the rechargeable lithium battery, the negative electrode may further include other binders. As other binders, non-aqueous binders, aqueous binders, dry binders and / or (for example, any suitable) combinations thereof may be used.

[0077] The non-aqueous binder may be polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, and / or (eg, any suitable) combinations thereof.

[0078] The aqueous binder can be selected from styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluororubber, polyethylene oxide, polyvinyl pyrrolidone, polyepichlorohydrin, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinyl pyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenol resin, epoxy resin, polyvinyl alcohol and / or (e.g., any suitable) combination thereof.

[0079] If (for example, when) an aqueous binder is used as a negative electrode binder, a cellulose compound capable of imparting viscosity may also be included. As the cellulose compound, a mixture of one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and alkali metal salts thereof may be used. As the alkali metal, Na, K, or Li may be used.

[0080] The dry binder is a polymer material that allows for fiberization, and may be, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and / or (eg, any suitable) combinations thereof.

[0081] Conductive materials can be used to impart conductivity to the electrode, and any conductive material can be used as long as it does not cause chemical changes in the battery and is an electronic conductive material. Non-limiting examples of conductive materials include: carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, carbon nanotube, etc.; metal-based materials including copper, nickel, aluminum, silver, etc. and in the form of metal powder or metal fiber; conductive polymers such as polyphenylene derivatives, etc.; and / or (e.g., any suitable) mixtures thereof.

[0082] The negative electrode current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a conductive metal-coated polymer substrate, and / or (eg, any suitable) combinations thereof.

[0083] The negative electrode active material layer may further include an additive. The additive may include one or more of a thickener, a dispersant, and a filler.

[0084] The content (e.g., amount) of the additive varies according to the type or kind of the active material, the composition of the binder, and the type or kind of the additive, and may be about 0.1 wt % to about 10 wt % relative to the binder composition excluding the solvent. Within the range, aspects of the additive may be expressed, and the relative proportion of the binder in the binder composition for the negative electrode may be ensured to express desired or appropriate aspects caused by the binder.

[0085] If (for example, when) the viscosity of the slurry is low, a thickener can be added to facilitate the coating process on the current collector. As a thickener, for example, one or more of carboxymethyl cellulose, carboxyethyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and polyvinyl alcohol can be selected and used. If (for example, when) the negative electrode active material layer also includes a conductive material, the negative electrode active material layer may include about 90wt% to about 98wt% of the negative electrode active material, about 1wt% to about 5wt% of the binder and about 1wt% to about 5wt% of the thickener.

[0086] The dispersant may be selected from materials that enhance the dispersibility of the negative electrode active material and the conductive material in the slurry. The dispersant may be selected from cationic dispersants, anionic dispersants, and nonionic dispersants, and may be selected and used from one or more of materials whose lipophilic portion is a C5 to C20 hydrocarbon, an acrylic acid oligomer, an ethylene oxide oligomer, a propylene oxide oligomer, an ethylene oxide / propylene oxide oligomer, or a urethane oligomer.

[0087] The current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a conductive metal-coated polymer substrate, and / or (eg, any suitable) combinations thereof.

[0088] Rechargeable lithium battery According to another aspect of the present disclosure, a rechargeable lithium battery is provided, the rechargeable lithium battery including the negative electrode described herein, a positive electrode, and an electrolyte.

[0089] Positive electrode A positive electrode for a rechargeable lithium battery may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0090] In one or more embodiments, the positive electrode may further include an additive that can function as a sacrificial positive electrode.

[0091] The positive electrode active material may be contained in an amount of about 90 wt % to about 99.5 wt % relative to 100 wt % of the positive electrode active material layer, and the binder and the conductive material may each be contained in an amount of about 0.5 wt % to about 5 wt % relative to 100 wt % of the positive electrode active material layer.

[0092] As the positive electrode active material, a compound capable of reversibly inserting / deinserting lithium ions (lithium insertion compound) can be used. For example, one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel and / or any suitable combination thereof can be used.

[0093] The composite oxide may be a lithium transition metal composite oxide, and non-limiting examples of the positive electrode active material include lithium nickel oxide, lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate compounds, cobalt-free nickel manganese oxide, and / or (eg, any suitable) combinations thereof.

[0094] In one or more embodiments, the positive electrode active material may be a compound represented by any one of 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 G e O2 (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, 0 ≤ e ≤ 0.1), Li a NiG b O2 (0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1), Li a CoG b O2 (0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1), Li a Mn 1-b G b O2 (0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1), Li a 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) and Li a FePO4 (0.90 ≤ a ≤ 1.8).

[0095] In the chemical formula, A may be Ni, Co, Mn, and / or (e.g., any suitable) combination thereof; X may be Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, and / or (e.g., any suitable) combination thereof; D may be O, F, S, P, and / or (e.g., any suitable) combination thereof; G may be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, and / or (e.g., any suitable) combination thereof; and L 1 It may be Mn, Al, and / or (eg, any suitable) combination thereof.

[0096] In one or more embodiments, the positive electrode active material can be a nickel-rich positive electrode active material, which includes nickel in an amount of about 80 mol% or more, about 85 mol% or more, about 90 mol% or more, about 91 mol% or more, or about 94 mol% or more and about 99 mol% or less relative to 100 mol% of the metal (excluding lithium) in the lithium transition metal composite oxide. The nickel-rich positive electrode active material can achieve high capacity and can therefore be applied to rechargeable lithium batteries with high capacity and high density.

[0097] The binder can be used to smoothly adhere the positive electrode active material particles to each other and to smoothly adhere the positive electrode active material particles to the current collector. Representative examples of the binder include polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth) acrylated styrene-butadiene rubber, epoxy resin, (meth) acrylic resin, polyester resin, nylon, etc., but the present disclosure is not limited thereto.

[0098] Conductive materials can be used to impart conductivity to the electrode, and any conductive material can be used as long as it does not cause chemical changes in the battery and is an electronic conductive material. Non-limiting examples of conductive materials include: carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, carbon nanotube, etc.; metal-based materials including copper, nickel, aluminum, silver, etc. and in the form of metal powder or metal fiber; conductive polymers such as polyphenylene derivatives, etc.; and / or (e.g., any suitable) mixtures thereof.

[0099] As the current collector, Al may be used, but the present disclosure is not limited thereto.

[0100] Electrolyte The electrolyte for a rechargeable lithium battery includes a non-aqueous organic solvent and a lithium salt.

[0101] The non-aqueous organic solvent may serve as a medium through which ions involved in an electrochemical reaction of a battery may migrate.

[0102] The non-aqueous organic solvent may be a carbonate solvent, an ester solvent, an ether solvent, a ketone solvent, an alcohol solvent, an aprotic solvent, and / or (eg, any suitable) combinations thereof.

[0103] As the carbonate solvent, dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), ethylmethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC) and the like can be used.

[0104] As the ester solvent, methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanoic acid lactone, mevalonolactone, valerolactone, caprolactone, or the like can be used.

[0105] As ether solvents, dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, etc. can be used. As ketone solvents, cyclohexanone, etc. can be used. As alcohol solvents, ethanol, isopropanol, etc. can be used, and as aprotic solvents, nitrile (such as R-CN (R is a C2 to C20 straight chain, branched or cyclic hydrocarbon group and can include a double bond, an aromatic ring or an ether group)); amides, such as dimethylformamide, etc.; dioxolanes, such as 1,3-dioxolane, 1,4-dioxolane, etc.; cyclopentane; etc. can be used.

[0106] As the nonaqueous organic solvent, those listed herein before may be used alone or in combination of two or more thereof.

[0107] In some embodiments, if (eg, when) a carbonate-based solvent is used, a mixture of a cyclic carbonate and a linear carbonate may be used, and the cyclic carbonate and the linear carbonate may be mixed in a volume ratio of 1:1 to 1:9.

[0108] The lithium salt may be a material that acts as a lithium ion source in the battery to allow the basic operation of the rechargeable lithium battery by dissolving in an organic solvent and is used to promote the migration of lithium ions between the positive electrode and the negative electrode. Representative examples of lithium salts include those 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+1SO2)(C y F 2y+ 1SO2) (x and y are integers of 1 to 20), at least one (e.g., one or two or more) of lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalato)phosphate (LiDFOB), and lithium bis(oxalato)borate (LiBOB).

[0109] According to the type or kind of the rechargeable lithium battery, a separator may be present between the positive electrode and the negative electrode.

[0110] Diaphragm As the diaphragm, polyethylene, polypropylene, polyvinylidene fluoride or a multilayer film of two or more layers thereof can be used, and a mixed multilayer film such as a double-layer diaphragm of polyethylene / polypropylene, a triple-layer diaphragm of polyethylene / polypropylene / polyethylene, and a triple-layer diaphragm of polypropylene / polyethylene / polypropylene can be used.

[0111] The separator may include a porous substrate and a coating layer disposed on one surface or both surfaces (eg, opposite surfaces) of the porous substrate, and may include an organic material, an inorganic material, and / or a (eg, any suitable) combination thereof.

[0112] The porous substrate can be a polymer film formed by any one polymer or copolymer selected from polyolefins (such as polyethylene, polypropylene, etc.), polyesters (such as polyethylene terephthalate, polybutylene terephthalate, etc.), polyacetals, polyamides, polyimides, polycarbonates, polyether ketones, polyaryletherketones, polyetherimides, polyamideimides, polybenzimidazoles, polyethersulfones, polyphenylene oxides, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fibers, Teflon, and polytetrafluoroethylene, or a mixture of at least two (e.g., two or more).

[0113] The organic material may include a polyvinylidene fluoride-based polymer or a (meth)acrylic polymer.

[0114] 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 (e.g., any suitable) combinations thereof, but the present disclosure is not limited thereto.

[0115] The organic material and the inorganic material may exist in a mixed state in one coating layer, or exist in the form of a coating layer including (eg, containing) an organic material and a coating layer including (eg, containing) an inorganic material stacked therein.

[0116] Rechargeable lithium batteries may be classified into a cylindrical form, a prismatic form, a pouch form, a coin form, etc. according to their shapes. Figures 1 to 4 each is a schematic diagram of a rechargeable lithium battery according to one or more embodiments, Figure 1 A cylindrical battery is shown, Figure 2 A prismatic cell is shown, and Figure 3 and Figure 4 A pouch type or bag type battery is shown. Figures 1 to 4 , the rechargeable lithium battery 100 may include an electrode assembly 40 in which a separator 30 is interposed between a positive electrode 10 and a negative electrode 20, and a case 50, and the electrode assembly 40 is embedded in the case 50. The positive electrode 10, the negative electrode 20, and the separator 30 may be impregnated with an electrolyte. Figure 1 As shown in , the rechargeable lithium battery 100 may include a sealing member 60 that seals the housing 50. Figure 2 In the embodiment, 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. Figure 3 and Figure 4 As shown in , the rechargeable lithium battery 100 may include electrode tabs 70 (ie, a positive electrode tab 71 and a negative electrode tab 72 ) that may serve as electrical paths for guiding current formed in the electrode assembly 40 to the outside.

[0117] The rechargeable lithium battery according to one or more embodiments of the present disclosure may be applied to vehicles, mobile phones, and / or one or more suitable types (kinds) of electrical devices, but the present disclosure is not limited thereto.

[0118] Terms such as "substantially", "about", and "approximately" are used as relative terms rather than as terms of degree, and are intended to account for the inherent deviations in measured or calculated values ​​that one of ordinary skill in the art will recognize. They may include the stated value and an acceptable range of deviation determined by one of ordinary skill in the art, taking into account 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.

[0119] The numerical ranges disclosed herein include and are intended to disclose all sub-ranges of the same numerical precision. For example, a 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 2.4 to 7.6. Therefore, the applicant reserves the right to amend this specification and claims to explicitly recite any sub-ranges contained within the ranges explicitly recited herein.

[0120] Hereinafter, examples and comparative examples of the present disclosure will be described.The following examples are given for illustrative purposes only and are not intended to limit the scope of the present disclosure.

[0121] Example Example 1 Based on the total amount of 100wt%, 15wt% of myrcene, 35wt% of n-butyl acrylate and 50wt% of styrene are mixed to obtain a monomer mixture. 100 weight portions of the resulting mixture are mixed with a sodium dodecylbenzene sulfonate emulsifier, an azo compound initiator and water. In this case, relative to the mixture of 100 weight portions, the emulsifier is used in an amount of 0.3 weight portion, and relative to the mixture of 100 weight portions, the initiator is used in an amount of 0.5 weight portion.

[0122] Subsequently, the resulting mixture is subjected to emulsion polymerization to prepare an aqueous binder dispersion containing a copolymer including a unit derived from myrcene, a unit derived from n-butyl acrylate, and a unit derived from styrene.

[0123] The aqueous binder dispersion, carboxymethyl cellulose thickener, and a mixture of graphite and silicon-carbon composite as a negative electrode active material are mixed in an aqueous solvent to prepare a negative electrode active material slurry. In this case, the negative electrode active material slurry is prepared so as to include 97 wt % of the negative electrode active material, 1 wt % of the carboxymethyl cellulose thickener, and 2 wt % of the binder based on the solid content (e.g., amount) excluding water.

[0124] The negative electrode active material slurry was coated on a copper foil current collector, dried, and roll-pressed to manufacture a negative electrode.

[0125] A battery with a single cell capacity of 700 milliampere hours (mAh) was manufactured by a typical method using a negative electrode, a positive electrode and an electrolyte. As an electrolyte, an electrolyte obtained by dissolving 1.5M LiPF6 in ethylene carbonate:ethyl methyl carbonate:dimethyl carbonate (volume ratio of 30:50:20) was used. As a positive electrode, a positive electrode formed by mixing 96wt% of LiCoO2, 2wt% of Ketjen black and 2wt% of polyvinylidene fluoride in an N-methylpyrrolidone solvent was used to prepare a positive electrode active material slurry, coating the positive electrode active material slurry on an aluminum current collector, and drying and rolling.

[0126] Example 2 to Example 5 An aqueous binder dispersion was prepared in substantially the same manner as in Example 1, except that the contents (e.g., amounts) of myrcene, n-butyl acrylate, and styrene in the monomer mixture were changed as shown in Table 1 based on 100 wt % of the total amount. A negative electrode and a battery were manufactured in substantially the same manner as in Example 1, except that the obtained aqueous binder dispersion was used.

[0127] Example 6 An aqueous binder dispersion was prepared in substantially the same manner as in Example 1, except that the contents (e.g., amounts) of ocimene, n-butyl acrylate, and styrene in the monomer mixture were changed as shown in Table 1 based on 100 wt % of the total amount. A negative electrode and a battery were manufactured in substantially the same manner as in Example 1, except that the obtained aqueous binder dispersion was used.

[0128] Example 7 An aqueous binder dispersion was prepared in substantially the same manner as in Example 1, except that the contents (e.g., amounts) of alloocimene, n-butyl acrylate, and styrene in the monomer mixture were changed as shown in Table 1 based on 100 wt % of the total amount. A negative electrode and a battery were manufactured in substantially the same manner as in Example 1, except that the obtained aqueous binder dispersion was used.

[0129] Comparative Example 1 An aqueous binder dispersion was prepared in substantially the same manner as in Example 1, except that 50 wt % of n-butyl acrylate and 50 wt % of styrene were used in the monomer mixture based on 100 wt % of the total amount. A negative electrode and a battery were manufactured in substantially the same manner as in Example 1, except that the obtained aqueous binder dispersion was used.

[0130] Comparative Example 2 An aqueous binder dispersion was prepared in substantially the same manner as in Example 1, except that 50 wt % of styrene and 50 wt % of butadiene were used in the monomer mixture based on 100 wt % of the total amount. A negative electrode and a battery were manufactured in substantially the same manner as in Example 1, except that the obtained aqueous binder dispersion was used.

[0131] Comparison Example 3 An aqueous binder dispersion was prepared in substantially the same manner as in Example 1, except that 35 wt % of n-butyl acrylate, 50 wt % of styrene, and 15 wt % of butadiene were used in the monomer mixture based on 100 wt % of the total amount. A negative electrode and a battery were manufactured in substantially the same manner as in Example 1, except that the obtained aqueous binder dispersion was used.

[0132] In Table 1, “-” indicates that the corresponding monomer is not included (the corresponding monomer content (eg, amount) is 0 wt %).

[0133] Experimental Example 1: DC internal resistance (DC-IR, unit: mΩ) Each battery having a single cell capacity of 700 milliampere hours (mAh) manufactured according to the aforementioned examples and comparative examples was charged and discharged once, wherein it was charged at a constant current / constant voltage of 0.2C / 4.2V and a cutoff value of 0.05C, left to stand for 10 minutes, and discharged at a constant current of 0.33C and a cutoff value of 2.5V, and left to stand for 10 minutes. The direct current internal resistance (DC-IR) was measured by measuring the voltage drop (V) occurring when a current of 1C was passed in the state of charge 50 (SOC50) for 10 seconds, and the state of charge 50 (SOC50) is the state in which the battery is charged to 50% of the charge capacity (and this also refers to the battery being discharged to 50%) if (for example, when) the total charge capacity of the battery is set to 100%. In some embodiments, the DC-IR is 100 milliohms (mΩ) or less.

[0134] Experimental Example 2: Adhesion force (unit: gf / mm) The adhesion between the current collector and the negative electrode active material layer in each of the negative electrodes manufactured according to the aforementioned examples and comparative examples was measured using a UTM tensile strength tester. Figure 5 The method of measuring adhesion is shown, in which a glass slide 1 (length × width = 7 cm × 2.5 cm) is attached to one surface of a double-sided adhesive tape 2 (length × width = 4 cm × 2.5 cm), and a negative electrode (3 + 4) is attached to the other surface of the double-sided adhesive tape to prepare Figure 5 The negative electrode (3+4) includes a current collector 4 and a negative electrode active material layer 3 each having a length×width=7 cm×2.5 cm. The sample is mounted on a universal testing machine (UTM) tensile strength tester, and the adhesion force is measured if (for example, when) the negative electrode (3+4) is detached from the glass slide 1 in the direction of the arrow at a peeling angle of 180°, a peeling temperature of 25°C, and a peeling speed of 100 millimeters per minute (mm / min). In some embodiments, the adhesion force is 1.20 grams-force per millimeter (gf / mm) or more.

[0135] Table 1

[0136] As shown in Table 1, the binders for a negative electrode of a rechargeable lithium battery according to Examples 1 to 7 provide a negative electrode active material layer having low electrode plate resistance and high adhesion to a current collector.

[0137] The battery management system (BMS) device and / or any other related device or component according to the embodiments of the present disclosure described herein may be implemented using any suitable hardware, firmware (e.g., an application specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, the components of the device may be formed on an integrated circuit (IC) chip or on separate IC chips. In addition, the components of the device may be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or formed on a substrate. In addition, the components of the device may be processes or threads that execute computer program instructions and interact with other system components for performing the functions described herein, running on one or more processors in one or more computing devices. The computer program instructions are stored in a memory that can be implemented in a computing device using a standard memory device (such as a random access memory (RAM) as an example). The computer program instructions may also be stored in other non-transitory computer-readable media, such as a CD-ROM, a flash drive, etc. as an example. In addition, those skilled in the art should recognize that, without departing from the scope of the present disclosure, the functions of the computing device may be combined or integrated into a single computing device, or the functions of a particular computing device may be distributed across one or more other computing devices.

[0138] The exemplary embodiments of the present disclosure have been described, but the present disclosure is not limited thereto. One or more suitable other modifications may be implemented within the scope of the claims, the specific embodiments of the present disclosure, and the drawings, and are also included within the scope of the present disclosure. Therefore, any modified embodiments may not be understood separately from the technical ideas and aspects of the present disclosure, and the modified embodiments are within the scope of the attached claims and their equivalents.

Claims

1. A binder, comprising: Units derived from aromatic vinyl monomers; Units derived from (meth)acrylate monomers; as well as Units derived from triene monomers, The binder is used in a negative electrode of a rechargeable lithium battery.

2. The adhesive according to claim 1, wherein The triene monomer is a monomer comprising Chemical Formula 1: Chemical formula 1 In Chemical Formula 1, R1, R2, R3, R4, R5, R6, R7 and R8 are each independently hydrogen or C1 to C5 alkyl, X and Z are each independently a single bond or a C1 to C5 alkylene group, M and N are each independently 0 or 1, and M+N is 1.

3. The adhesive according to claim 1, wherein The triene monomer includes at least one selected from the group consisting of myrcene of Chemical Formula 1-1, ocimene of Chemical Formula 1-2, and alloocimene of Chemical Formula 1-3: Chemical formula 1-1 Chemical formula 1-2 Chemical formula 1-3 。 4. The adhesive according to claim 1, wherein The (meth)acrylic acid ester monomer is a (meth)acrylic acid ester having a substituted or unsubstituted linear or branched C1 to C20 alkyl group in the ester portion.

5. The adhesive according to claim 1, wherein The aromatic vinyl-based monomer is a substituted or unsubstituted styrene-based monomer.

6. The adhesive according to claim 1, wherein The binder is a water-based binder.

7. The adhesive according to claim 1, wherein The binder is a (meth)acrylic copolymer of a monomer mixture, and the monomer mixture includes the aromatic vinyl-based monomer, the (meth)acrylic ester-based monomer, and the triene-based monomer.

8. The adhesive according to claim 7, wherein The amount of the triene-based monomer is 1 to 100 parts by weight relative to 100 parts by weight of the total amount of the aromatic vinyl-based monomer and the (meth)acrylic ester-based monomer.

9. The adhesive according to claim 7, wherein The amount of the triene monomer is 3 wt % to 45 wt % relative to the total amount of the monomer mixture.

10. The adhesive according to claim 7, wherein Relative to the total amount of the monomer mixture, the monomer mixture comprises: 3wt% to 45wt% of the triene monomer; 5wt% to 45wt% of the (meth)acrylate monomer; and 10wt% to 90wt% of the aromatic vinyl-based monomer.

11. The adhesive according to claim 10, wherein The triene monomer is at least one selected from the group consisting of myrcene, ocimene, alloocimene and combinations thereof.

12. The adhesive according to claim 10, wherein The (meth)acrylate monomer is at least one selected from 2-ethylhexyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, isobornyl acrylate, isovinyl acrylate, isovinyl methacrylate and combinations thereof.

13. The adhesive according to claim 10, wherein The aromatic vinyl monomer is at least one selected from the group consisting of styrene, α-methylstyrene, β-methylstyrene, p-tert-butylstyrene, chlorostyrene and combinations thereof.

14. The adhesive according to claim 10, wherein The triene-based monomer is myrcene, the (meth)acrylate-based monomer is n-butyl acrylate, and the aromatic vinyl-based monomer is styrene.

15. The adhesive according to claim 7, wherein The total amount of the aromatic vinyl-based monomer, the (meth)acrylate-based monomer, and the triene-based monomer is at least 99.5 wt % relative to the total amount of the monomer mixture.

16. The adhesive according to claim 1, wherein The binder includes a unit derived from a diene monomer, and an amount of the unit derived from the diene monomer is at most 0.1 wt % relative to the total amount of the binder.

17. The adhesive according to claim 1, wherein The binder is in the form of particles having an average particle size D50 of 10 nm to 500 nm.

18. A rechargeable lithium battery, comprising: A negative electrode comprising the binder according to claim 1; Positive electrode; as well as Electrolyte.

19. The rechargeable lithium battery according to claim 18, wherein: The binder comprises a (meth)acrylic copolymer of a monomer mixture, wherein the monomer mixture comprises an aromatic vinyl monomer, a (meth)acrylic ester monomer and a triene monomer. Relative to the total amount of the monomer mixture, the monomer mixture comprises: 3wt% to 45wt% of the triene monomer; 5wt% to 45wt% of the (meth)acrylate monomer; and 10wt% to 90wt% of the aromatic vinyl-based monomer.

20. The rechargeable lithium battery according to claim 19, wherein: The triene monomer is at least one selected from myrcene, ocimene, alloocimene and a combination thereof, The (meth)acrylate monomer is at least one selected from 2-ethylhexyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, isobornyl acrylate, isovinyl acrylate, isovinyl methacrylate, and combinations thereof, and The aromatic vinyl monomer is at least one selected from the group consisting of styrene, α-methylstyrene, β-methylstyrene, p-tert-butylstyrene, chlorostyrene and combinations thereof.

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