Negative electrode for rechargeable lithium battery and rechargeable lithium battery comprising the same

Abstract

Disclosed is a negative electrode for a rechargeable lithium battery and a rechargeable lithium battery including the same. The negative electrode includes a negative electrode active material layer including a negative electrode active material, an additive, and a binder. The additive includes MOH (where M is or includes an alkali metal) in a range of about 1: about 0.4 to about 1.5: about 0.4 to about 1.5 by weight, a polymer including R-O repeating units (where R is or includes a substituted or unsubstituted alkylene or phenylene), and a cationic polymer including an ammonium group.

Description

Technical Field

[0001] This disclosure relates to a negative electrode for a rechargeable lithium battery and a rechargeable lithium battery including the negative electrode. Background Technology

[0002] The increasing presence of battery-powered electronic devices (such as mobile phones, laptops, and electric vehicles) is driving a growing demand for rechargeable batteries with relatively high capacity and light weight. Specifically, rechargeable lithium-ion batteries have attracted attention as a power source for portable devices due to their lighter weight and higher energy density. Therefore, improving the performance of rechargeable lithium-ion batteries can be advantageous.

[0003] A rechargeable lithium battery includes a positive electrode and a negative electrode containing active materials capable of inserting and deintercalating lithium ions, as well as an electrolyte solution, and generates electrical energy through oxidation and reduction reactions when lithium ions are deintercalated from the positive electrode and inserted into the negative electrode, and deintercalated from the negative electrode and inserted into the positive electrode. Summary of the Invention

[0004] Some example embodiments include a negative electrode for rechargeable lithium batteries that exhibits both improved capacity and cycle life characteristics.

[0005] Another example embodiment includes a rechargeable lithium battery that includes the negative electrode.

[0006] One or more example embodiments include a negative electrode comprising a negative electrode active material layer comprising a negative electrode active material, additives, and a binder, wherein the additives comprise MOH (where M is or includes an alkali metal), a polymer comprising RO repeating units (where R is or includes substituted or unsubstituted alkylene or phenylene), and a cationic polymer comprising ammonium groups in a weight ratio ranging from about 1:about 0.4 to about 1.5:about 0.4 to about 1.5.

[0007] Another example embodiment includes a rechargeable lithium battery comprising a negative electrode, a positive electrode, and an electrolyte.

[0008] The negative electrode according to one or more example embodiments may exhibit desired or improved cycle life characteristics and desired or improved high-rate charge-discharge characteristics. Attached Figure Description

[0009] Figures 1 to 4 This is a schematic diagram illustrating a rechargeable lithium battery according to some example embodiments. Detailed Implementation

[0010] Example embodiments are described in detail below. However, these embodiments are merely examples, and this disclosure is not limited thereto; rather, this disclosure is defined by the scope of the claims.

[0011] As used herein, unless otherwise specifically defined, it is understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, the element may be directly on the other element, or there may be intervening elements therein.

[0012] Unless otherwise stated in this specification, things expressed in the singular may also include the plural. In addition, unless otherwise stated, "A or B" may mean "including A, including B, or including both A and B".

[0013] As used herein, “combination of” can refer to mixtures, laminates, complexes, copolymers, alloys, blends, reaction products, etc. of the components.

[0014] As used herein, unless otherwise defined, particle size can refer to the average particle size. Furthermore, particle size can refer to the average particle size (Dsize). 50 ), average particle size (D 50 The average particle size (D) represents the diameter of particles that constitute 50% of the cumulative volume in the particle size distribution. 50 The particle size can be measured using methods known to those skilled in the art, for example, by using a particle size analyzer, or by using a transmission electron microscope (TEM) or a scanning electron microscope (SEM). In some example embodiments, a dynamic light scattering measurement device is used to perform data analysis and count the number of particles in each particle size range. Thus, the average particle size (D) can be readily obtained by calculation. 50 The average particle size (D) is calculated based on 50% of the particle size distribution in the measuring device. In some example embodiments, laser diffraction can be used for measurement. When measured by laser diffraction, for example, the particles to be measured are dispersed in a dispersion medium, and then a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000) is introduced, and ultrasonic waves at approximately 28 kHz are irradiated with a 60 W output. 50 ).

[0015] In some example embodiments, the average particle size can be measured by the various methods described above, for example, by a particle size analyzer.

[0016] In some example embodiments, thickness may be measured using cross-sectional SEM or TEM images, but this disclosure is not limited thereto, and thickness may be measured using any method in the relevant art capable of measuring thickness. The thickness may be an average thickness.

[0017] As used herein, soft carbon refers to graphitizable carbon materials that can be graphitized by heat treatment at high temperatures (e.g., 2800°C), while hard carbon refers to non-graphitizable carbon materials that cannot be graphitized by heat treatment. Soft carbon and hard carbon are known in the art.

[0018] In some example embodiments, crystalline carbon and amorphous carbon can be classified by X-ray diffraction analysis. Crystalline carbon includes natural graphite and synthetic graphite. Natural graphite refers to naturally occurring graphite obtained by separation from minerals and has a d002 of about 3.350 Å to about 3.360 Å in X-ray diffraction analysis. Synthetic graphite refers to graphite produced by graphitization and has a d002 of about 3.355 Å to about 3.365 Å in X-ray diffraction analysis. Amorphous carbon has a d002 of less than or equal to about 3.34 Å when analyzed by X-ray diffraction. X-ray diffraction analysis (XRD) uses CuKα rays as the target line and uses an X-ray diffractometer, such as X'Pert (manufacturer: Malvern Panalytical), and to improve peak intensity resolution, the monochromator equipment can be removed and measurements performed. Measurement conditions can be 2θ = 10° to 80°, scanning speed (° / s) = 0.044 to 0.089, and step size (° / step) = 0.013 to 0.039.

[0019] In some example embodiments, the weight-average molecular weight can be measured, for example, by gel permeation chromatography.

[0020] When the terms “about” or “substantially” are used in conjunction with numerical values ​​in this specification, it is intended that the relevant numerical values ​​include a tolerance of ±10% around the stated value. When a range is specified, the range includes all values ​​within that range, such as increments of 0.1%.

[0021] The negative electrode for a rechargeable lithium battery according to one or more example embodiments includes a negative electrode active material layer, the negative electrode active material layer comprising a negative electrode active material, additives, and a binder. The additives include MOH (wherein M is or includes an alkali metal), polymers containing repeating RO units (wherein R is or includes substituted or unsubstituted alkylene or phenylene), and cationic polymers containing ammonium groups, in a weight ratio ranging from about 1:about 0.4 to about 1.5:about 0.4 to about 1.5.

[0022] In one or more example embodiments, the weight ratio of the MOH, the polymer containing the RO repeating unit, and the cationic polymer containing the ammonium group may be in the range of about 1: about 0.4 to about 1.2: about 0.4 to about 1.2.

[0023] When the weight ratio of MOH, polymer containing RO repeating units, and cationic polymer containing ammonium groups is within the above range, the processability of the negative electrode active material layer slurry and the negative electrode preparation can be ensured.

[0024] In an MOH, M is or includes an alkali metal, and may be or include Li, Na, or combinations thereof. For example, an MOH may be or include LiOH, NaOH, or combinations thereof.

[0025] In polymers containing repeating RO units, R can be or includes substituted or unsubstituted alkylene or phenylene. Alkylenes can be or include C2 to C30 alkylenes. In substituted alkylenes, the substituents can be or include halogenated or unsubstituted C1 to C5 alkylenes.

[0026] In one or more example embodiments, the polymer containing the RO repeating unit can be represented by the following chemical formula 1.

[0027] Chemical Formula 1: ; Wherein, R is or includes substituted or unsubstituted alkylene or phenylene, and n is an integer in the range of about 1 to about 200,000.

[0028] In one or more example embodiments, the polymer containing the RO repeating unit may be or include at least one of polyethylene oxide, polypropylene oxide, polyphenylene ether, and combinations thereof.

[0029] The cationic polymer containing an ammonium group may be or include at least one of polyethyleneimine, poly(diallyldimethylammonium chloride), poly(allylamine hydrochloride), poly(4-vinylbenzyltrimethylammonium chloride), and combinations thereof.

[0030] The additive can be neutral or weakly alkaline, and can have a pH range of, for example, from about 5 to about 9. Because the additive exhibits alkalinity, it can address the problems of viscosity reduction and processability degradation caused by the acidity of the slurry-type composition (negative electrode composition).

[0031] In one or more example embodiments, based on a 100 wt% negative electrode active material layer, the amount of additive can range from about 0.1 wt% or more, about 1 wt% or less, or from about 0.3 wt% to about 0.7 wt%. When the amount of additive meets the above ranges, the viscosity of the negative electrode composition can be maintained as needed, and the adhesion strength of the negative electrode active material layer to the current collector can be improved. The occurrence of negative electrode cracking can be reduced or suppressed, and the separation of the negative electrode active material during full charging can be effectively reduced or suppressed.

[0032] In one or more example embodiments, the adhesive may be or include a self-healing adhesive, a water-based adhesive, a non-water-based adhesive, or a combination thereof. In another example embodiment, the adhesive may be or include a self-healing adhesive, or may be a self-healing adhesive and a water-based adhesive.

[0033] When used in combination with a self-healing binder, the effects of the additives according to one or more example embodiments can be improved or maximized; therefore, including a self-healing binder in the binder may be suitable. The use of a self-healing binder and an aqueous binder can enhance the stability of the negative electrode slurry during its preparation, thereby ensuring improved processability.

[0034] Self-healing binders comprise copolymers, which include a polymeric electrolyte, a conductive polymer, and a multidentate chelating agent. The self-healing binder can be or includes a copolymer of a polymeric electrolyte, a conductive polymer, and a multidentate chelating agent. When the self-healing binder includes all three components, the desired self-healing effect (such as effectively reducing or suppressing the degradation of cycle life characteristics caused by volume expansion during charge and discharge) can be achieved, thus enhancing cycle life characteristics. When none of the polymeric electrolyte, conductive polymer, and multidentate chelating agent is included, the desired self-healing effect may not be obtained.

[0035] Because self-healing binders exhibit acidity, negative electrode compositions including the binder also exhibit acidity, which can lead to reduced viscosity and deterioration of the processability of the negative electrode preparation. Such problems can be reduced or prevented by using the self-healing binder in combination with additives according to one or more example embodiments in the negative electrode composition. For example, by adding an alkaline additive, the acidification of the negative electrode composition caused by the use of the self-healing binder can be neutralized, thereby effectively reducing or preventing the disadvantages associated with acidity.

[0036] In one or more example embodiments, the polymer electrolyte may be or include a polymer electrolyte having at least one functional group (such as or including at least one of carbonyl, undissociated functional group (RH), carboxylic acid, sulfonic acid, phosphoric acid, ether, and amino groups). The undissociated functional group (RH) may be or include at least one of carboxylic acid, sulfonic acid, and phosphoric acid groups. Non-limiting examples of polymer electrolytes may be or include at least one of poly(2-acrylamido-2-methyl-1-propanesulfonic acid), polyacrylic acid, poly(meth)acrylic acid, and combinations thereof. In one or more example embodiments, (meth)acrylic acid may refer to acrylic acid or methacrylic acid.

[0037] In one example embodiment, the conductive polymer may be or include at least one of poly(3,4-ethylenedioxythiophene), (PEDOT), polyaniline, polypyrrole, polyfuran, polythiophene, polyselenophene, 3,4-propylenedioxythiophene-2,5-dicarboxylic acid (ProDOT), and combinations thereof.

[0038] In one or more example embodiments, the multidentate chelating agent may have 2 to 6 acidic or basic functional groups, and the acidic or basic functional groups may be or include at least one of a carboxylic acid group (-COOH), a sulfonic acid group, an amino group, a phosphate group (-PO3H2), and a hydroxyl group (-OH). Non-limiting examples of multidentate chelating agents may be phytic acid, tannic acid, or combinations thereof.

[0039] In the self-healing binder, based on 100 wt% of the self-healing binder, the amount of polymeric electrolyte can be from about 30 wt% to about 95 wt%, from about 30 wt% to about 80 wt%, or from about 30 wt% to about 70 wt%. When the amount of polymeric electrolyte is within this range, desired or improved processability of the negative electrode can be obtained, and the dispersibility of the slurry used to prepare the negative electrode can be desired or improved, and high adhesive strength of the negative electrode can be achieved.

[0040] In the self-healing adhesive, based on 100 wt% of the self-healing adhesive, the amount of conductive polymer can be in the range of about 2 wt% to about 60 wt%, about 2 wt% to about 40 wt%, or about 10 wt% to about 40 wt%. Amounts of conductive polymer within the above ranges improve the conductivity of the negative electrode.

[0041] In the self-healing binder, based on 100 wt% of the self-healing binder, the amount of the multi-toothed chelating agent can be in the range of about 3 wt% to about 68 wt%, about 5 wt% to about 25 wt%, or about 15 wt% to about 40 wt%. When the amount of the multi-toothed chelating agent is within the above range, the self-healing performance of the negative electrode can be further improved.

[0042] The self-healing adhesive according to one or more example embodiments may be or include copolymers of polymeric electrolytes, conductive polymers and multidentate chelating agents that can be polymerized, and the weight-average molecular weight (Mw) of the copolymer is not limited, but may be in the range of about 5,000 g / mol to about 100,000,000 g / mol, for example.

[0043] In one or more example embodiments, the self-healing adhesive can be prepared by polymerizing a polymeric electrolyte, a conductive polymer, and a multidentate chelating agent, and the polymerization can be, but is not limited to, free radical polymerization. The polymerization technique can be any technique, as long as it can produce a copolymer. In the polymerization, the initiator can be, or includes, at least one, but is not limited to, ammonium persulfate, sodium persulfate, potassium persulfate, 2,2-azobis(2-amidinylpropane) dihydrochloride, 2,2-azobis(N,N-dimethylene)isobutamidine dihydrochloride, 2-(carbamoylazo)isobutyronitrile, 2,2-azobis2-(2-imidazolin-2-yl)propane dihydrochloride, and 4,4-azobis(4-cyanopentanoic acid) and combinations thereof.

[0044] The waterborne adhesive may be or include at least one of styrene-butadiene rubber (SBR), acrylated styrene-butadiene rubber (ABR), acrylonitrile-butadiene rubber, acryloyl rubber, butyl rubber, fluororubber, and combinations thereof.

[0045] Non-aqueous adhesives may be or include at least one of polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, and combinations thereof.

[0046] In one or more example embodiments, based on a 100wt% negative electrode active material layer, the amount of binder can be in the range of about 0.5wt% to about 10wt%, about 1wt% to about 5wt%, or about 3wt% to about 5wt%. When the amount of binder is within the above range, the capacity retention rate can be enhanced and the capacity can be further increased. For example, if the binder is a self-healing binder and its amount is within the range, a self-healing effect can be effectively obtained, that is, an effect for self-repairing negative electrode cracks caused by charging and discharging.

[0047] When the binder is or includes a self-healing binder and a water-based binder, the mixing ratio of the self-healing binder and the water-based binder can be a weight ratio in the range of about 1:10 to about 10:1 or a weight ratio of about 2:8 to about 8:2. When the mixing ratio of the self-healing binder and the water-based binder is within the above range, the processability of the negative electrode slurry and the negative electrode preparation can be enhanced.

[0048] In one or more example embodiments, the negative electrode active material layer may further comprise a cellulose compound. The cellulose compound may be or include at least one of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts. The alkali metal may be or include at least one of Na, K, and Li.

[0049] Based on 100 wt% of the negative electrode active material layer, the amount of the cellulose-based compound can be in the range of about 0.5 wt% to about 10 wt%, about 0.7 wt% to about 8 wt%, or about 1 wt% to about 6 wt%. When the amount of the cellulose-based compound falls within the above range, the dispersion of the active material and the conductive material can be improved, and the flexibility and adhesion of the negative electrode can be ensured.

[0050] In one or more exemplary embodiments, the negative electrode active material can be or include a silicon-based negative electrode active material. When the binder is applied to the silicon-based negative electrode active material rather than the carbon-based active material, the effect produced by the binder can be more effectively achieved. Although the silicon-based negative electrode active material can improve the current density and high capacity of the battery, the silicon-based negative electrode active material may undergo severe volume expansion during charge and discharge, which may cause cracks to occur in the negative electrode active material layer. The self-healing binder can effectively avoid or inhibit the generation of cracks and can form a uniform negative electrode active material layer when used together with the cellulose-based compound and the aqueous binder.

[0051] In one or more exemplary embodiments, the silicon-based negative electrode active material can be or include at least one of silicon, silicon oxide (SiO x , 0 < x ≤ 2), and a silicon-carbon composite including silicon and carbon.

[0052] The silicon-carbon composite can be or include a composite of silicon and carbon. The carbon can include amorphous carbon or a combination of amorphous carbon and crystalline carbon. The crystalline carbon can be natural graphite, artificial graphite or a combination thereof in an unspecified shape, plate-like, flaky, spherical or fibrous shape. The amorphous carbon can be or include at least one of soft carbon, hard carbon, mesophase pitch carbide, sintered coke and their combinations.

[0053] Silicon-carbon composites can take the form of silicon particles and amorphous carbon coated on the surface of the silicon particles. For example, a silicon-carbon composite may include silicon particles and an amorphous carbon coating on the surface of the silicon particles. In another example embodiment, the silicon-carbon composite may include secondary particles (cores) in which primary silicon particles are aggregated and an amorphous carbon coating (shell) on the surface of the secondary particles. Amorphous carbon may also be present between the primary silicon particles; for example, the primary silicon particles may be coated with amorphous carbon. For example, the secondary particles may be dispersed in an amorphous carbon matrix. The primary silicon particles may be or include nano-silicon particles. The average particle size of the nano-silicon particles may be in the range of about 10 nm to about 900 nm, about 10 nm to about 800 nm, about 10 nm to about 500 nm, about 10 nm to about 300 nm, or about 10 nm to about 200 nm. When the average particle size of the nano-silicon particles is within the above ranges, excessive volume expansion occurring during charge and discharge can be reduced or suppressed, and the interruption of conductive paths due to particle breakage during charge and discharge can be reduced or prevented. In one or more example embodiments, the particle size of the silicon secondary particles may be unrestricted.

[0054] The thickness of the amorphous carbon coating can be controlled as needed, but can be in the range of, for example, about 2 nm to about 800 nm, about 5 nm to about 600 nm, about 10 nm to about 400 nm, or about 20 nm to about 200 nm. The thickness of the amorphous carbon coating can be measured by SEM or TEM images of the cross-section of the silicon-carbon composite, but is not limited thereto, and any method in the relevant art capable of measuring the thickness of the amorphous carbon coating can be used.

[0055] The average particle size of the silicon-carbon composite can be appropriately controlled and can be, for example, less than or equal to about 30 μm, such as about 1 μm to about 30 μm, about 2 μm to about 25 μm, about 3 μm to about 20 μm, or about 5 μm to about 15 μm.

[0056] Based on a 100 wt% silicon-carbon composite, the amount of silicon particles can range from about 30 wt% to about 70 wt% or from about 40 wt% to about 65 wt%. Based on a 100 wt% silicon-carbon composite, the amount of amorphous carbon can range from about 30 wt% to about 70 wt% or from about 35 wt% to about 60 wt%. When the amounts of silicon particles and amorphous carbon meet the above ranges, higher capacity can be achieved.

[0057] In one or more example embodiments, the silicon-carbon composite may include a core comprising silicon particles and crystalline carbon, and an amorphous carbon coating layer on the surface of the core. For example, the silicon-carbon composite may include a core and an amorphous carbon coating layer on the core, the core comprising primary silicon particles and secondary particles of aggregated crystalline carbon. The amorphous carbon may be located between the primary silicon particles or between the crystalline carbon particles, such that the amorphous carbon can fill the spaces between the primary silicon particles or between the crystalline carbon particles.

[0058] When the silicon-carbon composite comprises silicon particles, crystalline carbon, and amorphous carbon, based on 100 wt% of silicon particles, amorphous carbon, and crystalline carbon, the amount of crystalline carbon can range from about 10 wt% to about 70 wt% or from about 20 wt% to about 60 wt%. The amount of amorphous carbon can range from about 20 wt% to about 40 wt% or from about 20 wt% to about 30 wt%, and the amount of silicon particles can range from about 10 wt% to about 70 wt% or from about 10 wt% to about 60 wt%.

[0059] In the negative electrode according to one or more example embodiments, in addition to silicon-based negative electrode active materials, carbon-based negative electrode active materials may also be included as negative electrode active materials. When silicon-based negative electrode active materials are used together with carbon-based negative electrode active materials, the mixing ratio of silicon-based negative electrode active materials and carbon-based negative electrode active materials can be in the range of about 1:99 to about 99:1 by weight. In one or more example embodiments, the mixing ratio of silicon-based negative electrode active materials and carbon-based negative electrode active materials can be in the range of about 5:95 to about 20:80 by weight.

[0060] Crystalline carbon may be or includes graphite, such as natural or artificial graphite in unspecified shape, in tabular, flake, spherical or fibrous form, and amorphous carbon may be or includes at least one of soft carbon, hard carbon, mesophase pitch carbide, sintered coke, etc.

[0061] In the negative electrode active material layer, based on a 100wt% negative electrode active material layer, the amount of negative electrode active material can be in the range of about 70wt% to about 98wt%.

[0062] In one or more example embodiments, the negative electrode active material layer may further include a conductive material. When the negative electrode active material layer also includes a conductive material, the amount of negative electrode active material in the negative electrode active material layer, based on 100 wt% of the negative electrode active material layer, may range from about 70 wt% to about 99 wt%; the total amount of additives and binders, and (optionally) cellulose compounds, based on 100 wt% of the negative electrode active material layer, may range from about 0.6 wt% to about 21 wt%; and the amount of conductive material, based on the total amount of the negative electrode active material layer of 100 wt%, may range from about 0.01 wt% to about 20 wt%.

[0063] Conductive materials may be included to provide conductivity for the negative electrode. Any electrically conductive material may be used as the conductive material unless it causes a chemical change. Non-limiting examples of conductive materials may include: carbon-based materials, such as at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, etc.; metallic materials such as metal powders or metal fibers, including at least one of copper, nickel, aluminum, silver, etc.; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0064] In one or more example embodiments, the negative electrode includes a current collector that supports the negative electrode active material layer.

[0065] The current collector may include, but is not limited to, at least one of copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, and combinations thereof.

[0066] Rechargeable lithium batteries: Another example embodiment includes a rechargeable lithium battery comprising a negative electrode, a positive electrode, and an electrolyte.

[0067] Positive electrode: The positive electrode includes a current collector and a layer of positive electrode active material formed on the current collector. The layer of positive electrode active material includes positive electrode active material and may also include a binder and / or a conductive material.

[0068] For example, the positive electrode may also include additives that can constitute a sacrificial positive electrode.

[0069] Based on a 100wt% positive electrode active material layer, the amount of positive electrode active material can be in the range of about 90wt% to about 99.5wt%, and based on a 100wt% positive electrode active material layer, the amounts of binder and conductive material can each be in the range of about 0.5wt% to about 5wt%.

[0070] The positive electrode active material may include a lithiation intercalation compound that can reversibly insert and deintercalate lithium ions. In one or more example embodiments, one or more composite oxides of metals (such as or including at least one of cobalt, manganese, nickel, and combinations thereof) and lithium may be used.

[0071] The composite oxide can be or includes lithium transition metal composite oxides, and examples of such composite oxides can include at least one of lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free lithium nickel-manganese oxides, and combinations thereof.

[0072] As an example, a compound represented by any of the following chemical formulas can be used. Li a A 1-b X b O2-c D c (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05);Li a Mn 2-b X b About 4-c D c (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05);Li a Ni 1-b-c Co b X c About 2-α D α (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.5,0<α<2);Li a Ni 1-b- c Mn b X c About 2-α D α (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.5,0<α<2);Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8,0≤b≤0.9,0≤c≤0.5,0≤d≤0.5,0≤e≤0.1);Li a NiG b O2(0.90≤a≤1.8,0.001≤b≤0.1);Li a CoG b O2(0.90≤a≤1.8,0.001≤b≤0.1);Li a Mn 1-b G b O2(0.90≤a≤1.8,0.001≤b≤0.1);Li a 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).

[0073] In the above chemical formulas, 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 It is or includes at least one of Mn, Al and combinations thereof.

[0074] For example, the positive electrode active material can be or includes a high-nickel positive electrode active material. Based on 100 mol% of metals other than lithium in the lithium transition metal composite oxide, the high-nickel positive electrode active material has a nickel content of 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%. High-nickel positive electrode active materials can achieve high capacity and can be applied to high-capacity, high-density rechargeable lithium batteries.

[0075] The binder is configured to adhere positive electrode active material particles to each other and to adhere the positive electrode active material to the current collector. Non-limiting examples of the binder may include at least one of, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylate resin, polyester resin, and nylon.

[0076] Conductive materials can provide electrode conductivity for the positive electrode, and any electrically conductive material can be used as the conductive material unless it causes a chemical change. Non-limiting examples of conductive materials may include: carbon-based materials, such as at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, carbon nanotubes, etc.; metallic materials such as metal powders or metal fibers, including at least one of copper, nickel, aluminum, silver, etc.; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0077] Current collectors may include Al, but are not limited to this.

[0078] Electrolytes: Electrolytes include non-aqueous organic solvents and lithium salts.

[0079] Non-aqueous organic solvents constitute the medium for transporting ions that participate in the electrochemical reactions of the battery.

[0080] Non-aqueous organic solvents may be or include at least one of carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, aprotic solvents, and combinations thereof.

[0081] Carbonate solvents may 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), and butyl carbonate (BC).

[0082] Ester solvents may include at least one of the following: methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanoic acid lactone, γ-butyrolactone, mevalonate lactone, valeronate lactone, caprolactone, etc.

[0083] Ether solvents may include at least one of dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, etc. Ketone solvents may include cyclohexanone, etc. Alcohol solvents may include ethanol, isopropanol, etc. Aprotic solvents may include at least one of the following: nitriles, such as R-CN (wherein R is a C2 to C20 straight-chain, branched, or cyclic hydrocarbon group, and may include double bonds, aromatic rings, or ether groups, etc.); amides, such as dimethylformamide; dioxolane, such as 1,3-dioxolane, 1,4-dioxolane, etc.; sulfolane, etc.

[0084] Non-aqueous organic solvents can be used alone or in mixtures of two or more types of solvents.

[0085] When using carbonate solvents, cyclic carbonates and chain carbonates can be mixed, and the cyclic carbonates and chain carbonates can be mixed in a volume ratio ranging from about 1:1 to about 1:9.

[0086] The electrolyte may also include at least one of the following as an additive: vinyl ethyl carbonate, vinylene carbonate, difluoroethylene carbonate, chloroethylene carbonate, dichloroethylene carbonate, bromoethylene carbonate, dibromoethylene carbonate, nitroethylene carbonate, cyanoethylene carbonate, fluoroethylene carbonate, and combinations thereof.

[0087] Lithium salts dissolved in organic solvents supply lithium ions in batteries, enabling rechargeable lithium batteries to operate and improving lithium ion transport between the positive and negative electrodes. Non-limiting examples of lithium salts may include at least one of the following: 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+ 1SO2) (where x and y are integers from about 1 to about 20), lithium trifluoromethane sulfonate, lithium tetrafluoroethane sulfonate, lithium difluoro(oxalate)borate (LiDFOB), lithium difluorobis(oxalate)phosphate (LiDFBOP), and lithium bis(oxalate)borate (LiBOB).

[0088] Diaphragm: Depending on the type of rechargeable lithium battery, a separator may be present between the positive and negative electrodes. Suitable separator materials may include at least one of polyethylene, polypropylene, polyvinylidene fluoride, and multilayers thereof (such as polyethylene / polypropylene double-layer separators, polyethylene / polypropylene / polypropylene triple-layer separators, and polypropylene / polypropylene / polypropylene triple-layer separators).

[0089] The membrane may include a porous substrate and a coating layer on one or both surfaces of the porous substrate, comprising organic materials, inorganic materials or combinations thereof.

[0090] The porous substrate may be or include a membrane formed or comprising any one or two or more copolymers or mixtures of the following: polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetal, polyamide, polyimide, polycarbonate, polyetherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fiber, and polytetrafluoroethylene (TEFLON).

[0091] Organic materials may include polymers such as polyvinylidene fluoride or (meth)acrylic acid polymers.

[0092] Inorganic materials may include, but are not limited to, inorganic particles containing 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.

[0093] Organic and inorganic materials can be mixed in a coating layer, or a coating layer containing organic materials and a coating layer containing inorganic materials can be stacked together.

[0094] Rechargeable lithium batteries can be classified into cylindrical, square, pouch, and coin types based on their shape. Figures 1 to 4 This is a schematic diagram illustrating a rechargeable lithium battery according to some example embodiments. Figure 1 A cylindrical battery is shown. Figure 2 A prismatic battery is shown, and Figure 3 and Figure 4 A pouch-type battery is shown. (See reference) Figures 1 to 4 The rechargeable lithium battery 100 includes an electrode assembly 40 and a housing. The electrode assembly 40 includes a separator 30 between a positive electrode 10 and a negative electrode 20, and the electrode assembly 40 is housed within the housing. The positive electrode 10, the negative electrode 20, and the separator 30 may be impregnated with an electrolyte (not shown). Figure 1 As shown, the rechargeable lithium battery 100 may include a sealing member 60 of the sealed housing 50. Figure 2 In this context, the rechargeable lithium battery 100 may include a positive electrode lead connector 11, a positive electrode terminal 12 connected to the positive electrode lead connector 11, a negative electrode lead connector 21, and a negative electrode terminal 22 connected to the negative electrode lead connector 21. For example... Figure 3 and Figure 4 As shown, the rechargeable lithium battery 100 includes Figure 4 The electrode connector 70 shown is or Figure 3 The positive electrode terminal 71 and negative electrode terminal 72 shown herein form an electrical path for guiding the current generated in the electrode assembly 40 to the outside of the rechargeable lithium battery 100.

[0095] The rechargeable lithium battery according to one or more example embodiments can be used in, for example, automobiles, mobile phones and / or various types of electronic devices, but this disclosure is not limited thereto.

[0096] Examples and comparative examples of this disclosure are described below. However, these examples should not in any sense be construed as limiting the scope of the disclosure.

[0097] Example 1: An additive was prepared by mixing LiOH, polyethylene oxide (PEO), and polyethyleneimine (PEI) in a weight ratio of 40:30:30.

[0098] A copolymer of polyacrylic acid (PAA), phytic acid (PA), and poly(3,4-ethylenedioxythiophene) (PEDOT) was prepared by free radical polymerization using ammonium persulfate (APS) initiator, followed by filtration and drying to obtain a self-healing adhesive. The copolymer (weight average molecular weight: 1,000,000 g / mol) of PAA, phytic acid, and PEDOT was used as a self-healing adhesive. In the prepared self-healing adhesive, based on 100 wt% of the self-healing adhesive, the amount of polyacrylic acid was 70 wt%, the amount of phytic acid was 20 wt%, and the amount of poly(3,4-ethylenedioxythiophene) was 10 wt% of the self-healing adhesive.

[0099] A slurry of negative electrode active material was prepared by mixing 95.5 wt% of a mixture of artificial graphite and silicon-carbon composite as negative electrode active material (mixing ratio of artificial graphite and silicon-carbon composite = 96:4 by weight), 1 wt% of carboxymethyl cellulose, 1.5 wt% of styrene-butadiene rubber, 0.5 wt% of additives and 1.5 wt% of self-healing binder in water.

[0100] The silicon-carbon composite comprises aggregates and a soft carbon coating layer formed on the aggregates. The aggregates are secondary particles of artificial graphite and silicon aggregates. Here, based on the total amount of the silicon-carbon composite, the amount of artificial graphite is 50 wt%, the amount of silicon nanoparticles is 30 wt%, and the amount of amorphous carbon is 20 wt%.

[0101] The negative electrode active material slurry was coated onto a Cu foil current collector and dried at 110°C, followed by pressing. The resulting product was then further dried under vacuum at 140°C for 4 hours to prepare the negative electrode.

[0102] A half-cell is constructed using a negative electrode, a lithium metal counter electrode, and an electrolyte. The electrolyte is 1.0 M LiPF6 dissolved in a mixed solvent of ethylene carbonate, ethyl methyl carbonate, and dimethyl carbonate (30:50:20 volume ratio).

[0103] Example 2: The negative electrode and half-cell are manufactured using essentially the same steps as in Example 1, except that a slurry of the negative electrode active material is prepared by mixing 95.9 wt% of a mixture of artificial graphite and silicon-carbon composite as the negative electrode active material (mixing ratio of artificial graphite and silicon-carbon composite = 96:4 by weight), 1 wt% of carboxymethyl cellulose, 1.5 wt% of styrene-butadiene rubber, 0.1 wt% of additives, and 1.5 wt% of self-healing binder in water.

[0104] Example 3: The negative electrode and half-cell are manufactured using essentially the same steps as in Example 1, except that a slurry of the negative electrode active material is prepared by mixing 95 wt% of a mixture of artificial graphite and silicon-carbon composite (mixing ratio of artificial graphite and silicon-carbon composite = 96:4 by weight), 1 wt% of carboxymethyl cellulose, 1.5 wt% of styrene-butadiene rubber, 1 wt% of additives, and 1.5 wt% of self-healing binder in water.

[0105] Example 4: The negative electrode and half cell are manufactured using essentially the same steps as in Example 1, except that LiOH, polyethylene oxide (PEO), and polyethyleneimine (PEI) are mixed in a weight ratio of 30:35:35 (i.e., 1:about 1.17:about 1.17) to prepare the additive.

[0106] Example 5: The negative electrode and half-cell are manufactured using essentially the same steps as in Example 1, except that LiOH, polyethylene oxide (PEO), and polyethyleneimine (PEI) are mixed in a weight ratio of 50:25:25 (i.e., 1:0.5:0.5) to prepare the additive.

[0107] Example 6: The negative electrode and half-cell are manufactured using essentially the same steps as in Example 1, except that LiOH, polyethylene oxide (PEO), and polyethyleneimine (PEI) are mixed in a weight ratio of 45:35:20 (i.e., 1:about 0.78:about 0.4) to prepare the additive.

[0108] Example 7: The negative electrode and half-cell are manufactured using essentially the same steps as in Example 1, except that LiOH, polyethylene oxide (PEO), and polyethyleneimine (PEI) are mixed in a weight ratio of 35:25:40 (i.e., 1:about 0.7:about 1.14) to prepare the additive.

[0109] Example 8: The negative electrode and half-cell are manufactured using essentially the same steps as in Example 1, except that LiOH, polyethylene oxide (PEO), and polyethyleneimine (PEI) are mixed in a weight ratio of 45:20:35 (i.e., 1:about 0.4:about 0.78) to prepare the additive.

[0110] Example 9: The negative electrode and half-cell are manufactured using essentially the same steps as in Example 1, except that LiOH, polyethylene oxide (PEO), and polyethyleneimine (PEI) are mixed in a weight ratio of 35:40:25 (i.e., 1:about 1.14:about 0.7) to prepare the additive.

[0111] Compare with Example 1: A negative electrode active material slurry was prepared by mixing 96 wt% of a mixture of artificial graphite and silicon-carbon composite (mixing ratio of artificial graphite to silicon-carbon composite = 96:4 by weight), 1 wt% of carboxymethyl cellulose, 1.5 wt% of styrene-butadiene rubber, and 1.5 wt% of a self-healing binder in water. The negative electrode active material slurry was coated onto a Cu foil current collector and dried at 110°C, followed by pressing. The resulting product was then further dried under vacuum at 140°C for 4 hours to prepare the negative electrode. However, a uniform negative electrode was not obtained using this process. Therefore, battery manufacturing is not feasible.

[0112] Compare with Example 2: The negative electrode active material slurry was prepared using essentially the same steps as in Example 1, except that an additive was used, prepared by mixing LiOH, polyethylene oxide, and polyethyleneimine in a weight ratio of 20:40:40 (i.e., 1:2:2). The negative electrode active material slurry was coated onto a Cu foil current collector and dried at 110°C, followed by pressing. The resulting product was then further dried under vacuum at 140°C for 4 hours to prepare the negative electrode. However, the negative electrode was not successfully prepared using this process. Therefore, battery fabrication is not feasible.

[0113] Compare with Example 3: The negative electrode active material slurry was prepared using essentially the same steps as in Example 1, except that an additive was used, prepared by mixing LiOH, polyethylene oxide, and polyethyleneimine in a weight ratio of 60:20:20 (i.e., 1:approx. 0.3:approx. 0.3). The negative electrode active material slurry was coated onto a Cu foil current collector and dried at 110°C, followed by pressing. The resulting product was then further dried under vacuum at 140°C for 4 hours to prepare the negative electrode. However, the negative electrode was not successfully prepared using this process. Therefore, battery fabrication is not feasible.

[0114] Compare with Example 4: The negative electrode and half-cell are manufactured using essentially the same steps as in Example 2, except that an additive is used, which is prepared by mixing LiOH, polyethylene oxide and polyethyleneimine in a weight ratio of 50:40:10 (i.e., 1:0.8:0.2).

[0115] Compare with Example 5: The negative electrode is prepared using essentially the same steps as in Example 2, except that an additive is used, which is prepared by mixing LiOH, polyethylene oxide and polyethyleneimine in a weight ratio of 30:20:50 (i.e., 1:about 0.7:about 1.67).

[0116] The half-cell is manufactured using essentially the same steps as in Example 1, except that a negative electrode is used.

[0117] Compare with Example 6: The negative electrode is prepared using essentially the same steps as in Example 2, except that an additive is used, which is prepared by mixing LiOH, polyethylene oxide and polyethyleneimine in a weight ratio of 50:10:40 (i.e. 1:0.2:0.8).

[0118] The half-cell is manufactured using essentially the same steps as in Example 1, except that a negative electrode is used.

[0119] Compare with Example 7: The negative electrode is prepared using essentially the same steps as in Example 2, except that an additive is used, which is prepared by mixing LiOH, polyethylene oxide and polyethyleneimine in a weight ratio of 30:50:20 (i.e., 1:about 1.67:about 0.67).

[0120] The half-cell is manufactured using essentially the same steps as in Example 1, except that a negative electrode is used.

[0121] The composition of the negative electrode according to Examples 1 to 9 and Comparative Examples 1 to 7 is summarized in Table 1 below.

[0122] Table 1:

[0123] Experimental Example 1) Evaluation of Emulsification Index The negative electrode slurries according to Examples 1 to 9 and Comparative Examples 1 to 7 were allowed to stand for three days, and the phase separation region was evaluated, for example, by measuring the height of the phase separation point. The emulsification index was calculated by dividing the measured height by the slurry height before standing. The results are shown in Table 2 below.

[0124] Experimental Example 2) Evaluation of the Adhesion Strength of the Negative Electrode The adhesion strength of the negative electrodes according to Examples 1 to 9 and Comparative Examples 1 to 7 was measured by the following steps.

[0125] Adhesive tape was attached to the glass slide and then to the negative electrode active material layer. The adhesive strength was measured by peeling the tape and the negative electrode active material layer using a 180° universal tensile testing machine (UTM). The peeling speed was set to 100 mm / min, and the adhesive strength was measured three (3) times to calculate the average strength required for a 40 mm peel. The results are shown in Table 2 below.

[0126] Experimental Example 3) Evaluation of the occurrence of electrolyte side reactions Electrolyte side reactions of the negative electrodes according to Examples 1 to 9 and Comparative Examples 1 to 7 were confirmed by observing battery expansion caused by gas generation. After formation and charging / discharging, cases where battery expansion was visually observed were marked as "O", and cases where no expansion was observed were marked as "X", as shown in Table 2 below.

[0127] Experimental Example 4) Evaluation of the separation ratio of a fully charged negative electrode The half-cells according to Examples 1 to 9 and Comparative Examples 1 to 7 were fully charged at 4.2V, 0.1C, and 0.02C cutoff. The negative electrode was then separated after charging.

[0128] By comparing the area of ​​the negative electrode before charging with the area that remains attached to the current collector after charging, cases with a value less than 90% are marked as separation (O), and cases with a value of 90% or greater are marked as no separation (X), as shown in Table 2 below.

[0129] Experimental Example 5) Evaluation of Battery Resistance The resistance of the half-cells according to Examples 1 to 9 and Comparative Examples 1 to 7 was evaluated using DC internal resistance (DC-IR). For resistance measurement, the battery was charged and discharged at 0.5C at SOC50 (based on 100% total battery charge capacity, charged to 50% charge capacity), and then discharged at 1C for 10 seconds at SOC50. The resistance of the battery after undergoing the above charge and discharge process was measured.

[0130] The results are shown in Table 2 below.

[0131] Table 2:

[0132] As shown in Table 2, the negative electrodes of Examples 1 to 9 exhibited the desired or improved adhesion strength during full charging, with no electrolyte side reactions and no negative electrode separation. Furthermore, the negative electrodes of Examples 1 to 9 exhibited low battery resistance.

[0133] In contrast, in Comparative Example 1, which did not use additives, it was impossible to manufacture a negative electrode and a battery. Comparative Examples 2 and 3, which used additives with an inappropriate mixing ratio of LiOH, PEO, and PEI, failed to manufacture negative electrodes and batteries, and Comparative Example 4 exhibited low adhesion strength and significantly high battery resistance. Comparative Example 5 showed electrolyte side reactions, therefore, battery evaluation was not possible. Comparative Example 6 showed extremely high battery resistance, and Comparative Example 7 exhibited low adhesion strength and negative electrode separation during full charging, therefore, battery evaluation was not possible.

[0134] While this disclosure has been described in conjunction with exemplary embodiments now considered to be practical, it will be understood that the disclosure is not limited to the disclosed embodiments. Rather, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A negative electrode for a rechargeable lithium battery, the negative electrode comprising: The negative electrode active material layer includes the negative electrode active material, additives, and binders. The additives comprise, by weight, the following components in the range of 1:0.4 to 1.5:0.4 to 1.5: MOH, where M includes alkali metals; A polymer comprising repeating RO units, wherein R comprises substituted or unsubstituted alkylene or phenylene; and Cationic polymers containing ammonium groups.

2. The negative electrode for a rechargeable lithium battery according to claim 1, wherein, M includes at least one of Li, Na, and combinations thereof.

3. The negative electrode for a rechargeable lithium battery according to claim 1, wherein, The polymer containing RO repeating units is represented by chemical formula 1: Chemical Formula 1: ， in: R is a substituted or unsubstituted alkylene or phenylene, and n is an integer in the range of 1 to 200,000.

4. The negative electrode for a rechargeable lithium battery according to claim 1, wherein, The polymer containing RO repeating units includes at least one of polyethylene oxide, polypropylene oxide, polyphenylene ether, and combinations thereof.

5. The negative electrode for a rechargeable lithium battery according to claim 1, wherein, The ammonium-containing cationic polymers include at least one of polyethyleneimine, poly(diallyldimethylammonium chloride), poly(allylamine hydrochloride), poly(4-vinylbenzyltrimethylammonium chloride), and combinations thereof.

6. The negative electrode for a rechargeable lithium battery according to claim 1, wherein, The negative electrode active material includes silicon-based negative electrode active materials.

7. The negative electrode for a rechargeable lithium battery according to claim 1, wherein, Based on 100 wt% of the negative electrode active material layer, the amount of the additive is 0.1 wt% or more and 1.0 wt% or less.

8. The negative electrode for a rechargeable lithium battery according to claim 1, wherein, The adhesive includes at least one of self-healing adhesives, water-based adhesives, non-water-based adhesives, and combinations thereof.

9. The negative electrode for a rechargeable lithium battery according to claim 8, wherein, The adhesive includes a self-healing adhesive.

10. The negative electrode for a rechargeable lithium battery according to claim 8, wherein, The adhesives include self-healing adhesives and water-based adhesives.

11. The negative electrode for a rechargeable lithium battery according to claim 8, wherein, The adhesive includes a self-healing adhesive, which includes a copolymer, and the copolymer includes at least one of a polymeric electrolyte, a conductive polymer, and a multidentate chelating agent.

12. The negative electrode for a rechargeable lithium battery according to claim 8, wherein, The adhesive includes self-healing adhesives and water-based adhesives. The self-healing adhesive includes copolymers, and the copolymers include at least one of polymeric electrolytes, conductive polymers, and multidentate chelating agents.

13. The negative electrode for a rechargeable lithium battery according to claim 11, wherein, The polymer electrolyte includes at least one functional group, which includes at least one of carbonyl, undissociated functional group RH, carboxylic acid, sulfonic acid, phosphate, ether, and amino groups.

14. The negative electrode for a rechargeable lithium battery according to claim 11, wherein, The polymer electrolyte includes at least one of poly(2-acrylamido-2-methyl-1-propanesulfonic acid), polyacrylic acid, poly(meth)acrylic acid, and combinations thereof.

15. The negative electrode for a rechargeable lithium battery according to claim 11, wherein, The conductive polymer includes at least one of poly(3,4-ethylenedioxythiophene), polyaniline, polypyrrole, polyfuran, polythiophene, polyselenophene, 3,4-propylenedioxythiophene-2,5-dicarboxylic acid, and combinations thereof.

16. The negative electrode for a rechargeable lithium battery according to claim 11, wherein, The multidentate chelating agent has 2 to 6 acidic or basic functional groups.

17. The negative electrode for a rechargeable lithium battery according to claim 16, wherein, One of the acidic functional groups or one of the basic functional groups includes at least one of a carboxylic acid group, a sulfonic acid group, an amino group, a phosphate group, and a hydroxyl group.

18. The negative electrode for a rechargeable lithium battery according to claim 11, wherein, The multidentate chelating agent includes at least one of phytic acid, tannic acid, and combinations thereof.

19. A rechargeable lithium battery, said rechargeable lithium battery comprising: The negative electrode according to any one of claims 1 to 18; Positive electrode; and Electrolytes.

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