Positive electrode composition for lithium secondary battery containing multifunctional surface deterioration prevention additive, positive electrode for lithium secondary battery and lithium secondary battery including same, method for manufacturing positive electrode composition for lithium secondary battery containing multifunctional surface deterioration prevention additive, and method for manufacturing slurry including same

Abstract

The present invention relates to a positive electrode composition for a lithium secondary battery to which a multifunctional surface deterioration prevention additive is added. The positive electrode composition comprises: a positive electrode active material including a lithium transition metal oxide; and at least one functional group having an organic framework and capable of bonding to a transition metal atom.

Description

A positive electrode composition for a lithium secondary battery with a multifunctional surface degradation prevention additive added thereto, a positive electrode for a lithium secondary battery and a lithium secondary battery comprising the same, a method for producing a positive electrode composition for a lithium secondary battery with a multifunctional surface degradation prevention additive added thereto, and a method for producing a slurry comprising the same

[0001] The present invention relates to a positive electrode composition for a lithium secondary battery and a manufacturing method thereof, wherein surface deterioration is prevented by adding a multifunctional surface deterioration prevention additive.

[0002] Lithium secondary batteries generate electrical energy by exploiting the oxidation and reduction reactions that occur when lithium ions are inserted and removed from the anode and cathode. Therefore, materials capable of insertion and extraction of lithium ions are used as the anode and cathode, and the cathode material, in particular, plays a crucial role in determining the battery's capacity and performance.

[0003] One approach to improving the capacity and performance of lithium secondary batteries involves designing the cathode active material to be a lithium transition metal oxide containing nickel (Ni). Nickel significantly increases battery capacity by increasing the number of lithium ions that can enter the lithium layer within the lithium transition metal oxide. Nickel also offers the advantages of low production costs and environmental friendliness.

[0004] As such, increased nickel content translates into increased capacity for lithium secondary batteries. Therefore, active efforts are being made to adopt lithium transition metal oxides containing high nickel content as cathode active materials. However, increasing nickel content also presents challenges.

[0005] As the nickel content increases, the surface deterioration of the cathode active material becomes more severe.

[0006] The cause is cation mixing. This is a phenomenon that mainly occurs on the surface of the cathode active material, and nickel (Ni) in an ionic state is contained in the lithium transition metal oxide. 2+ ) of similar size lithium ions (Li+ ) is a phenomenon that takes the place of .

[0007] This blocks the movement path of lithium ions on the surface of the positive electrode material, reducing the output and energy density of the battery.

[0008] In addition, it causes irreversible phase transformation of lithium transition metal oxides located on the surface of the cathode active material, easily causes cracks to form in the cathode active material particles, and causes the transition metal to dissolve through the cracks that occur. The dissolution of the transition metal reduces the capacity and lifespan of the battery.

[0009] In addition, hydrofluoric acid (HF) generated by electrochemical decomposition of the electrolyte corrodes metal materials such as battery containers and current collectors, and causes transition metals to be dissolved through cracks that occur on the surface of positive electrode active material particles.

[0010] The phenomenon of surface deterioration of lithium transition metal oxides caused by high nickel content is also found in cathode active materials containing other transition metal components, such as LiCoO2, LiFePO4, LiMn2O4, and OLO (Over-lithiated Oxide).

[0011] Coating and doping methods have been introduced in the past as methods to prevent such surface deterioration phenomena, but each has limitations in that it cannot avoid surface deterioration due to phase transformation and corrosion, and another method, a synthesis method that adjusts the ratio of ternary transition metals constituting the positive electrode active material stepwise from the particle surface to the center, has the problem of a complicated process.

[0012] Therefore, it can be said that the development of a method that effectively prevents surface deterioration of lithium transition metal oxide-based cathode active materials containing transition metals, especially those containing a high nickel content, and at the same time is easy for industrial application is a major task for the industry.

[0013] In order to solve the above-described problems of the present invention, the present invention provides a lithium secondary battery positive electrode composition having a multifunctional surface deterioration prevention additive added thereto, which effectively suppresses surface deterioration of a lithium transition metal oxide-based positive electrode active material containing a transition metal, particularly containing a high content of nickel, while being easy to apply to industry, a positive electrode for a lithium secondary battery comprising the same, and a lithium secondary battery.

[0014] Another object of the present invention is to provide a method for producing a positive electrode composition for a lithium secondary battery to which the aforementioned multifunctional surface degradation prevention additive is applied and a slurry containing the same.

[0015] In order to solve the above-described problem, the present invention provides a positive electrode composition for a lithium secondary battery with a multifunctional surface degradation prevention additive, comprising a positive electrode active material including a lithium transition metal oxide and an organic skeleton, and including an additive including at least one functional group capable of bonding with a transition metal atom, wherein the additive can bind to a transition metal atom present on the surface of the positive electrode active material and suppress the transition metal atom from moving within the lithium transition metal oxide lattice.

[0016] In one embodiment of the present invention, the functional group may be bonded to a transition metal atom through a condensation reaction.

[0017] In one embodiment of the present invention, the organic skeleton is sp 2 May contain carbon.

[0018] In one embodiment of the present invention, the organic skeleton may include unshared electrons.

[0019] In one embodiment of the present invention, the cathode active material may include at least one of the cathode active materials represented by the following chemical formulas 1 to 5.

[0020] [Chemical Formula 1]

[0021] LiCoO2

[0022] [Chemical Formula 2]

[0023] LiNi 1-x-y Co x Mn y O2

[0024] In the above chemical formula 2, 0 <x≤0.2, 0<y≤0.2이다.

[0025] [Chemical Formula 3]

[0026] LiMaPO4

[0027] In the above chemical formula 3, Ma is one or more elements selected from Fe, Co, Ni, and Mn.

[0028] [Chemical Formula 4]

[0029] LiMb2O4

[0030] In the above chemical formula 4, Mb is one or more elements selected from Mn, Ni, and Co.

[0031] [Chemical Formula 5]

[0032] Li a M' b M'' c M''' d O2

[0033] In the above chemical formula 5, each of M', M'', and M''' may be one or more elements selected from Fe, Co, Ni, and Mn. In the above chemical formula 5, 1 <a, (a-1)+b+c+d=1일 수 있다.

[0034] In one embodiment of the present invention, the organic skeleton includes a porphyrin-based organic substance, and the functional group may include at least one selected from the group consisting of a hydroxyl group (-OH), a carboxyl group (-COOH), a sulfonic acid group (-SO3H), and a combination thereof.

[0035] In one embodiment of the present invention, the additive may include one or more of the compounds represented by the following chemical formulas 6 to 17.

[0036] [Correction pursuant to Rule 91, September 12, 2025]

[0037] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 6] [Chemical Formula 7]

[0038] [Correction pursuant to Rule 91, September 12, 2025]

[0039] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 8] [Chemical Formula 9]

[0040] [Correction pursuant to Rule 91, September 12, 2025]

[0041] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 10] [Chemical Formula 11]

[0042] [Correction pursuant to Rule 91, September 12, 2025]

[0043] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 12] [Chemical Formula 13]

[0044] [Correction pursuant to Rule 91, September 12, 2025]

[0045] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 14] [Chemical Formula 15]

[0046] [Correction pursuant to Rule 91, September 12, 2025]

[0047] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 16] [Chemical Formula 17]

[0048] In one embodiment of the present invention, the additive may be added in an amount of 1 wt% or less relative to the positive electrode active material.

[0049] Another embodiment of the present invention for solving the above-described problem may be a lithium secondary battery positive electrode including a lithium secondary battery positive electrode composition to which a multifunctional surface deterioration prevention additive is added, and a lithium secondary battery including the same.

[0050] Another embodiment of the present invention for solving the above-described problem is a method for manufacturing a positive electrode composition for a lithium secondary battery with a multifunctional surface degradation prevention additive added, comprising the steps of mixing a positive electrode active material including a lithium transition metal oxide and an additive in an organic solvent environment, performing centrifugal separation, and drying in an oven, wherein the additive may include at least one functional group capable of bonding with an organic skeleton and a transition metal atom.

[0051] In one embodiment of the present invention, the mixing step may be performed at 10°C to 80°C.

[0052] Another embodiment of the present invention for solving the above-described problem is a method for manufacturing a positive electrode slurry for a lithium secondary battery with a multifunctional surface degradation prevention additive, comprising the steps of preparing a positive electrode composition including a positive electrode active material including a lithium transition metal oxide and an additive, and mixing the positive electrode composition with a conductive material, a binder, and a solvent to manufacture a slurry, wherein the additive may include at least one functional group capable of bonding to an organic skeleton and a transition metal atom.

[0053] In one embodiment of the present invention, the step of preparing the positive electrode composition may include the step of mixing the positive electrode active material including the lithium transition metal oxide and the additive in an organic solvent environment, the step of performing centrifugal separation, and the step of drying in an oven.

[0054] In one embodiment of the present invention, the step of preparing the positive electrode composition may include the step of preparing a positive electrode active material powder including a lithium transition metal oxide and the step of mixing the positive electrode active material powder with an additive.

[0055] In one embodiment of the present invention, the mixing step may be performed at 5°C to 80°C.

[0056] The present invention has the advantage that nickel is fixed within the lattice according to the above-described configuration and bonding relationship, thereby suppressing nickel displacement and resulting phase transformation, and effectively suppressing surface deterioration.

[0057] In addition, it has the advantage of forming a stable CEI (cathode electrolyte interphase) around the cathode active material, thereby suppressing the formation of cracks in the cathode active material and preventing the elution of transition metals.

[0058] Additionally, it has the advantage of preventing the reduction in battery capacity and lifespan by capturing corrosive hydrofluoric acid (HF) and preventing corrosion caused by hydrofluoric acid and the elution of transition metals.

[0059] In addition, the multifunctional surface deterioration prevention additive disclosed in the present invention can be expected to have a surface deterioration prevention effect even when simply added to a lithium transition metal oxide-based cathode active material, and thus has the advantage of being very easy to apply to industry.

[0060] In addition, the multifunctional surface deterioration prevention additive disclosed in the present invention can prevent surface deterioration even in a small amount, and is also inexpensive, so it has an economical advantage.

[0061] In addition, the multifunctional surface degradation prevention additive disclosed in the present invention can be mixed with a lithium transition metal oxide-based cathode active material and exhibit an effect through a room temperature process, so it is easy to apply in various stages of lithium secondary battery manufacturing, and has an economical advantage in terms of process cost.

[0062] FIG. 1 is a drawing showing the movement of lithium ions at the interface between a lithium transition metal oxide-based cathode active material and an electrolyte during charging and discharging of a lithium secondary battery, and the appearance of an additive disclosed in one embodiment of the present invention being combined with the cathode active material.

[0063] FIG. 2 illustrates the appearance of an additive disclosed in one embodiment of the present invention being bonded to the periphery of a lithium transition metal oxide-based cathode active material and the properties of the functional group and organic skeleton in the additive.

[0064] FIG. 3 is a flowchart of a method for manufacturing a positive electrode composition for a lithium secondary battery with a multifunctional surface degradation prevention additive added according to one embodiment of the present invention.

[0065] FIG. 4 is a flowchart of a method for manufacturing a positive electrode slurry for a lithium secondary battery with a multifunctional surface degradation prevention additive added according to one embodiment of the present invention.

[0066] FIG. 5 is a flowchart showing one embodiment of detailed steps of the step of preparing the bipolar composition in FIG. 4.

[0067] FIG. 6 is a flowchart showing another embodiment of the detailed steps of the step of preparing the bipolar composition in FIG. 4.

[0068] Figure 7 is an SEM image of (a) NCM811 and (b) NCM811 with TCPP added.

[0069] Figure 8 is a TEM image of NCM811 with TCPP added.

[0070] Figure 9 shows the results of measuring the initial capacity of lithium secondary batteries manufactured including comparative group 1, comparative group 2, and experimental group 1.

[0071] Figure 10 shows the results of measuring the rate characteristics of lithium secondary batteries manufactured including comparative group 1, comparative group 2, and experimental group 1.

[0072] Figure 11 shows the results of measuring the life characteristics of lithium secondary batteries manufactured including comparative group 1, comparative group 2, and experimental group 1.

[0073] Figure 12 is an SEM image showing the surface and internal corrosion state of the cathode active material after a life characteristic test of a lithium secondary battery manufactured including Comparative Group 1, Comparative Group 2, and Experimental Group 1.

[0074] Figure 13 shows the results of measuring the rate characteristics of lithium secondary batteries manufactured including comparative group 3 and experimental group 2.

[0075] Figure 14 shows the results of measuring the life characteristics of lithium secondary batteries manufactured including comparative group 3 and experimental group 2.

[0076] Figure 15 shows the results of measuring the life characteristics of lithium secondary batteries manufactured using the comparative group 4 and experimental group 3 methods.

[0077] This specification clarifies the scope of the present invention and explains the principles of the present invention and discloses embodiments thereof to enable those skilled in the art to practice the invention. The disclosed embodiments may be implemented in various forms.

[0078] It should be understood that terms such as “include,” “may include,” or “have,” which may be used in various embodiments of the present invention, are intended to indicate the presence of a feature described in the specification (e.g., a function, a number, a step, an operation, a component, a part, or a combination thereof), and do not preclude the possibility of the presence or addition of one or more other features.

[0079] As used herein, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0080] When a component is referred to as being “connected, coupled” to another component, it should be understood that the component may be directly connected or coupled to the other component, but that there may also be a new component between the component and the other component. Conversely, when a component is referred to as being “directly connected” or “directly coupled” to another component, it should be understood that no new component exists between the component and the other component.

[0081] The terms "first," "second," etc., used herein may be used to describe various components, but the components should not be limited by the terms. The terms are used solely to distinguish one component from another.

[0082] Hereinafter, a preferred embodiment of a positive electrode composition for a lithium secondary battery to which a multifunctional surface degradation prevention additive according to one embodiment of the present invention is added will be described in detail.

[0083] First, the present invention relates to a positive electrode composition for a lithium secondary battery to which a multifunctional surface degradation prevention agent is added, and which comprises a positive electrode active material including a lithium transition metal oxide and an additive.

[0084] The additive disclosed in the present invention can prevent surface deterioration of the positive electrode active material simply by adding it to the positive electrode active material and mixing it, and has the advantage of not requiring high-temperature heat treatment or a special synthesis method.

[0085] Below, we will examine each configuration in detail.

[0086] <Cathode active material>

[0087] Here, the cathode active material is a cathode active material that can be used in a lithium ion secondary battery, and may be a lithium transition metal oxide-based cathode active material.

[0088] In one embodiment, the cathode active material including a lithium transition metal oxide may include at least one of the cathode active materials represented by the following chemical formulas 1 to 5.

[0089] [Chemical Formula 1]

[0090] LiCoO2

[0091] [Chemical Formula 2]

[0092] LiNi 1-x-y Co x Mn y O2

[0093] In the above chemical formula 2, 0 <x≤0.2, 0<y≤0.2일 수 있다. 예를 들어, 상기 화학식 2는 LiNi 0.6 Co 0.2 Mn 0.2 It could be O2.

[0094] Preferably, 0 in the above chemical formula 2 <x≤0.1, 0<y≤0.1일 수 있다. 예를 들어, 상기 화학식 2는 LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.85 Co 0.75 Mn 0.75 It could be O2.

[0095] More preferably, 0 in the above chemical formula 2 <x≤0.05, 0<y≤0.05일 수 있다. 예를 들어, 상기 화학식 2는 LiNi 0.9 Co 0.05 Mn 0.05 It could be O2.

[0096] [Chemical Formula 3]

[0097] LiMaPO4

[0098] In the above chemical formula 3, Ma is one or more elements selected from Fe, Co, Ni, and Mn. For example, the above chemical formula 3 may be LiFePO4.

[0099] [Chemical Formula 4]

[0100] LiMb2O4

[0101] In the above chemical formula 4, Mb is one or more elements selected from Mn, Ni, and Co. For example, the above chemical formula 4 may be LiMn2O4.

[0102] [Chemical Formula 5]

[0103] Li a M' b M'' c M''' d O2

[0104] In the above chemical formula 5, each of M', M'', and M''' may be one or more elements selected from Fe, Co, Ni, and Mn. In the above chemical formula 5, 1 <a, (a-1)+b+c+d=1일 수 있다.

[0105] Additionally, the cathode active material may include a material that can be conventionally coated or doped on a lithium transition metal oxide-based cathode active material, without being limited thereto.

[0106] Additives

[0107] In one embodiment of the present invention, the additive may be a material including a functional group capable of bonding to a transition metal atom in an organic skeleton.

[0108] FIG. 1 is a drawing showing the movement of lithium ions at the interface between a lithium transition metal oxide-based cathode active material and an electrolyte during charging and discharging of a lithium secondary battery, and the appearance of an additive disclosed in one embodiment of the present invention being combined with the cathode active material.

[0109] Referring to Figure 1, insertion and extraction of lithium ions occur at the surface of the positive electrode active material forming an interface with the electrolyte.

[0110] During this process, a cation mixing phenomenon may occur, in which lithium ions are desorbed from the lithium transition metal oxide lattice and the vacant spaces are occupied by transition metals.

[0111] Cation mixing occurs more readily as the content of transition metals in lithium transition metal oxides increases. When cation mixing occurs, transition metal ions block the migration paths through which lithium ions intercalate and deintercalate, thereby reducing the output and energy density of lithium secondary batteries. Furthermore, the movement of transition metal ions within the lattice causes phase transformation of the lithium transition metal oxide, destabilizing the lattice.

[0112] This cation mixing phenomenon is the main cause of surface deterioration of lithium transition metal oxide-based cathode active materials.

[0113] The additive disclosed in the present invention is a material containing a functional group capable of bonding with a transition metal atom, and as illustrated in FIG. 1, can form a bond with a transition metal atom within a lithium transition metal oxide lattice on the surface of a positive electrode active material.

[0114] Accordingly, the mobility of transition metal atoms is restricted, fixing their positions within the lithium transition metal oxide lattice. By restricting the mobility of transition metals, the aforementioned cation mixing phenomenon is suppressed, preventing surface deterioration of the cathode active material and preventing a decline in the output and energy density of lithium secondary batteries.

[0115] Specifically, the additive disclosed in the present invention may be a substance containing at least one functional group capable of bonding with a transition metal atom through a condensation reaction.

[0116] Additionally, each functional group may form a bond with one or two transition metal atoms within the cathode active material lattice.

[0117] For example, the functional group may include at least one selected from the group consisting of a hydroxyl group (-OH), a carboxyl group (-COOH), a sulfonic acid group (-SO3H), and combinations thereof, and the hydroxyl group, the carboxyl group, and the sulfonic acid group may each form a bond with one to two transition metal atoms within the positive electrode active material lattice. Preferably, the functional group may include at least one carboxyl group (-COOH).

[0118] Additionally, in one embodiment of the present invention, the additive may include at least two functional groups, either homologous or heterologous, in the organic skeleton, and each of the two or more functional groups included in the additive may form a bond with one or two transition metal atoms within the cathode active material lattice.

[0119] For example, the additive may contain two or more carboxyl groups (-COOH), in which case each carboxyl group may form bonds with up to two transition metal atoms, such that the additive as a whole may form bonds with four or more transition metal atoms by the two or more carboxyl groups.

[0120] Accordingly, transition metal atoms within the cathode active material lattice can be more effectively fixed with a small amount of additive, and surface deterioration of the cathode active material can be more effectively prevented.

[0121] At this time, two or more functional groups included in the organic skeleton may be selected from the group consisting of a hydroxyl group (-OH), a carboxyl group (-COOH), a sulfonic acid group (-SO3H), and a combination thereof.

[0122] Next, in one embodiment of the present invention, the additive has an organic skeleton, and the organic skeleton is sp 2 May contain carbon.

[0123] FIG. 2 illustrates the appearance of an additive disclosed in one embodiment of the present invention being bonded to the periphery of a lithium transition metal oxide-based cathode active material and the properties of the functional group and organic skeleton in the additive.

[0124] Referring to Figure 2, the additive is sp 2 Because it contains carbon, it is stable in organic electrolytes and has lithium affinity. In addition, the aforementioned functional group forms a bond with transition metals, showing transition metal affinity.

[0125] Therefore, when the additive is added to the cathode active material, the functional group faces the cathode active material and the organic skeleton faces the electrolyte, and the additive can surround the cathode active material in a micelle structure without any special conditions or treatments.

[0126] Also, the sp of the additive that surrounds the positive electrode active material 2 Carbon, due to its lithium affinity, facilitates the formation of a cathode electrolyte interphase (CEI) around the cathode active material and stabilizes the resulting CEI. This suppresses cracking in the cathode active material particles and prevents the dissolution of transition metals in these cracks, thereby preventing a decline in the capacity and lifespan of lithium secondary batteries.

[0127] Next, in one embodiment of the present invention, an additive disclosed has an organic skeleton, and the organic skeleton may include unshared electrons. Preferably, the organic skeleton may include electron donor nitrogen.

[0128] Unpaired electrons can capture hydrofluoric acid (HF), which is generated by the electrochemical decomposition of the organic electrolyte during long-term battery operation. Hydrofluoric acid is a corrosive substance that corrodes metallic materials such as the battery container and current collector, and causes transition metals to leach through cracks that form on the surface of the cathode active material particles.

[0129] Therefore, the additive can suppress corrosion by retaining hydrofluoric acid by including unshared electrons, prevent transition metals from being eluted from the cathode active material, and improve the long-term operation stability of lithium secondary batteries.

[0130] As an example of an organic skeleton having the aforementioned characteristics, the additive disclosed in the present invention may include a porphyrin-based organic material as the organic skeleton.

[0131] In addition, as an example of an additive disclosed in the present invention having an organic skeleton and functional group having the above-described characteristics, it may include one or more of the compounds represented by the following chemical formulas 6 to 17. Preferably, it may be Tetrakis(4-carboxyphenyl)porphyrin.

[0132] [Correction pursuant to Rule 91, September 12, 2025]

[0133] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 6] [Chemical Formula 7]

[0134] [Correction pursuant to Rule 91, September 12, 2025]

[0135] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 8] [Chemical Formula 9]

[0136] [Correction pursuant to Rule 91, September 12, 2025]

[0137] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 10] [Chemical Formula 11]

[0138] [Correction pursuant to Rule 91, September 12, 2025]

[0139] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 12] [Chemical Formula 13]

[0140] [Correction pursuant to Rule 91, September 12, 2025]

[0141] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 14] [Chemical Formula 15]

[0142] [Correction pursuant to Rule 91, September 12, 2025]

[0143] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 16] [Chemical Formula 17]

[0144] In one embodiment of the present invention, the additive may be added in an amount of 1 wt% or less relative to the positive electrode active material.

[0145] That is, the additive disclosed in one embodiment of the present invention has an advantage of effectively binding to a cathode active material even in a small amount due to a functional group having transition metal affinity and an organic skeleton having lithium affinity, suppressing movement of transition metal atoms within the lattice, effectively wrapping the cathode active material so that a cathode electrolyte interphase (CEI) is stably formed and maintained, and also suppressing corrosion of hydrofluoric acid (HF), thereby effectively preventing surface deterioration of the cathode active material even in a very small amount of 1 wt% or less compared to the cathode active material.

[0146] Next, according to another embodiment of the present invention, a positive electrode for a lithium secondary battery and a lithium secondary battery including a positive electrode composition for a lithium secondary battery to which the multifunctional surface degradation prevention additive is added can be provided.

[0147] The positive electrode for a lithium secondary battery disclosed in this example and the lithium secondary battery including the same also include a positive electrode composition for a lithium secondary battery to which a multifunctional surface deterioration prevention additive is added, and show excellent characteristics in terms of capacity, output, and lifespan, which will be described in detail through experimental examples described below.

[0148] Next, with reference to FIG. 3, a method for manufacturing a positive electrode composition for a lithium secondary battery with a multifunctional surface degradation prevention additive added, which is another embodiment of the present invention, will be described.

[0149] FIG. 3 is a flowchart of a method for manufacturing a positive electrode composition for a lithium secondary battery with a multifunctional surface degradation prevention additive added according to one embodiment of the present invention.

[0150] A method for manufacturing a positive electrode composition for a lithium secondary battery with a multifunctional surface degradation prevention additive added according to one embodiment disclosed in the present invention may include a step of mixing a positive electrode active material and an additive in an organic solvent environment (S100), a step of performing centrifugal separation (S200), a washing step (not shown), and a step of drying in an oven (S300).

[0151] The step of mixing the cathode active material and the additive in an organic solvent environment (S100) is a step of introducing the cathode active material containing a lithium transition metal oxide and the additive into an organic solvent and mixing them.

[0152] Specifically, the cathode active material including a lithium transition metal oxide may include at least one of the cathode active materials represented by the following chemical formulas 1 to 5, similar to the above-described examples.

[0153] [Chemical Formula 1]

[0154] LiCoO2

[0155] [Chemical Formula 2]

[0156] LiNi 1-x-y Co x Mn y O2

[0157] In the above chemical formula 2, 0 <x≤0.2, 0<y≤0.2일 수 있다. 예를 들어, 상기 화학식 2는 LiNi 0.6 Co 0.2 Mn 0.2 It could be O2.

[0158] Preferably, 0 in the above chemical formula 2 <x≤0.1, 0<y≤0.1일 수 있다. 예를 들어, 상기 화학식 2는 LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.85 Co 0.75 Mn 0.75It could be O2.

[0159] More preferably, 0 in the above chemical formula 2 <x≤0.05, 0<y≤0.05일 수 있다. 예를 들어, 상기 화학식 2는 LiNi 0.9 Co 0.05 Mn 0.05 It could be O2.

[0160] [Chemical Formula 3]

[0161] LiMaPO4

[0162] In the above chemical formula 3, Ma is one or more elements selected from Fe, Co, Ni, and Mn. For example, the above chemical formula 3 may be LiFePO4.

[0163] [Chemical Formula 4]

[0164] LiMb2O4

[0165] In the above chemical formula 4, Mb is one or more elements selected from Mn, Ni, and Co. For example, the above chemical formula 4 may be LiMn2O4.

[0166] [Chemical Formula 5]

[0167] Li a M' b M'' c M''' d O2

[0168] In the above chemical formula 5, each of M', M'', and M''' may be one or more elements selected from Fe, Co, Ni, and Mn. In the above chemical formula 5, 1 <a, (a-1)+b+c+d=1일 수 있다.

[0169] Additionally, the cathode active material may include a material that can be conventionally coated or doped on a lithium transition metal oxide-based cathode active material, without being limited thereto.

[0170] Next, the additive may be a material containing a functional group capable of bonding with a transition metal atom in an organic skeleton, similar to the aforementioned embodiment. Accordingly, the additive may form a bond with a transition metal atom within a lithium transition metal oxide lattice on the surface of the positive electrode active material.

[0171] Specifically, the additive disclosed in the present invention may be a substance containing at least one functional group capable of bonding with a transition metal atom through a condensation reaction.

[0172] Additionally, each functional group may form a bond with one or two transition metal atoms within the cathode active material lattice.

[0173] For example, the functional group may include at least one selected from the group consisting of a hydroxyl group (-OH), a carboxyl group (-COOH), a sulfonic acid group (-SO3H), and combinations thereof, and the hydroxyl group, the carboxyl group, and the sulfonic acid group may each form a bond with one to two transition metal atoms within the positive electrode active material lattice. Preferably, the functional group may include at least one carboxyl group (-COOH).

[0174] Additionally, in one embodiment of the present invention, the additive may include at least two functional groups, either homologous or heterologous, in the organic skeleton, and each of the two or more functional groups included in the additive may form a bond with one or two transition metal atoms within the cathode active material lattice.

[0175] Accordingly, transition metal atoms within the cathode active material lattice can be more effectively fixed with a small amount of additive, and surface deterioration of the cathode active material can be more effectively prevented.

[0176] At this time, two or more functional groups included in the organic skeleton may be selected from the group consisting of a hydroxyl group (-OH), a carboxyl group (-COOH), a sulfonic acid group (-SO3H), and a combination thereof.

[0177] Additionally, the additive has an organic skeleton, and the organic skeleton is sp 2 May contain carbon.

[0178] Additionally, the additive has an organic skeleton, and the organic skeleton may include unpaired electrons. Preferably, the organic skeleton may include electron donor nitrogen.

[0179] An example of an additive having the aforementioned properties may include a porphyrin-based organic material as the organic skeleton.

[0180] For example, the additive may include one or more of the compounds represented by the following chemical formulae 6 to 17. Preferably, it may be Tetrakis(4-carboxyphenyl)porphyrin.

[0181] [Correction pursuant to Rule 91, September 12, 2025]

[0182] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 6] [Chemical Formula 7]

[0183] [Correction pursuant to Rule 91, September 12, 2025]

[0184] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 8] [Chemical Formula 9]

[0185] [Correction pursuant to Rule 91, September 12, 2025]

[0186] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 10] [Chemical Formula 11]

[0187] [Correction pursuant to Rule 91, September 12, 2025]

[0188] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 12] [Chemical Formula 13]

[0189] [Correction pursuant to Rule 91, September 12, 2025]

[0190] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 14] [Chemical Formula 15]

[0191] [Correction pursuant to Rule 91, September 12, 2025]

[0192] [Correction pursuant to Rule 91, September 12, 2025] [Chemical Formula 16] [Chemical Formula 17]

[0193] At this time, the additive may be added in an amount of 1 wt% or less relative to the positive electrode active material.

[0194] That is, the additive disclosed in one embodiment of the present invention has an advantage of effectively binding to a cathode active material even in a small amount due to a functional group having transition metal affinity and an organic skeleton having lithium affinity, suppressing movement of transition metal atoms within the lattice, effectively wrapping the cathode active material so that a cathode electrolyte interphase (CEI) is stably formed and maintained, and also suppressing corrosion of hydrofluoric acid (HF), thereby effectively preventing surface deterioration of the cathode active material even in a very small amount of 1 wt% or less compared to the cathode active material.

[0195] Next, the solvent into which the positive electrode active material and additives are added may be an organic solvent.

[0196] An example of an organic solvent may include, but is not limited to, ethanol.

[0197] Next, the method of mixing the cathode active material and additive in an organic solvent environment may be magnetic stirring, but is not limited thereto.

[0198] In particular, the process of mixing the positive electrode active material and additives in an organic solvent environment can be performed at room temperature.

[0199] Specifically, the room temperature may be 0°C to 100°C. Alternatively, it may be 10°C to 100°C. Alternatively, it may be 0°C to 80°C. Preferably, it may be 10°C to 80°C. More preferably, it may be 20°C to 50°C.

[0200] The step of performing centrifugal separation (S200) is performed after mixing the positive electrode active material and the additive in an organic solvent environment by magnetic stirring, etc., and is intended to obtain only the positive electrode active material (or positive electrode composition) to which the additive is combined.

[0201] The washing step is performed to wash the obtained positive electrode composition (or positive electrode active material combined with an additive), and the drying step (S300) in an oven can be performed to remove moisture or organic solvent remaining in the positive electrode composition.

[0202] Next, with reference to FIGS. 3 to 6, a method for manufacturing a positive electrode slurry for a lithium secondary battery with a multifunctional surface degradation prevention additive added, which is another embodiment of the present invention, will be described.

[0203] FIG. 3 is a flow chart of a method for producing a positive electrode composition for a lithium secondary battery with a multifunctional surface degradation prevention additive added thereto according to one embodiment of the present invention. FIG. 4 is a flow chart of a method for producing a positive electrode slurry for a lithium secondary battery with a multifunctional surface degradation prevention additive added thereto according to one embodiment of the present invention. FIG. 5 is a flow chart showing one embodiment of detailed steps of the step of preparing the positive electrode composition in FIG. 4. FIG. 6 is a flow chart showing another embodiment of detailed steps of the step of preparing the positive electrode composition in FIG. 4.

[0204] Referring to FIG. 4, a method for manufacturing a positive electrode slurry for a lithium secondary battery with a multifunctional surface degradation prevention additive added according to one embodiment disclosed in the present invention may include a step of preparing a positive electrode composition (S1000) and a step of manufacturing a slurry (S2000).

[0205] The step of preparing the bipolar composition (S1000) can be divided into three methods again.

[0206] Looking at the first method for preparing a positive electrode composition, it can be prepared according to the method for manufacturing a positive electrode composition for a lithium secondary battery to which the aforementioned multifunctional surface degradation prevention additive is added.

[0207] As shown in Fig. 3, it may include a step of mixing a positive electrode active material and an additive in an organic solvent environment (S100), a step of performing centrifugal separation (S200), a washing step, and a step of drying in an oven (S300).

[0208] At this time, the details of the positive electrode active material, additive, organic solvent, and performing method can be interpreted in the same manner as described in the above-described example (e.g., method for producing positive electrode slurry for lithium secondary battery with multifunctional surface deterioration prevention additive added), and duplicate descriptions will be omitted.

[0209] Referring to FIG. 5, a second method for preparing a positive electrode composition may include a step of preparing positive electrode active material powder (S1110) and a step of mixing positive electrode active material powder and an additive (S1120).

[0210] This is a method of simply mixing positive electrode active material powder and additives and adding them during slurry production.

[0211] Simple mixing can be understood as mixing the positive electrode active material and additives in powder form in a container and shaking them, or stirring them with a hand or a stick, without any special device (e.g., a stirring device, a ball milling device, etc.) or special conditions (e.g., heating, pressurized conditions, or solvent conditions, etc.).

[0212] In addition, this method simplifies the manufacturing process of a cathode slurry for a lithium secondary battery and has an economic advantage because it does not require special equipment or special conditions that are required in existing coating methods, milling methods, doping methods, etc.

[0213] At this time, the detailed properties and examples of the cathode active material and additives used are the same as in the above-described examples, and duplicate descriptions will be omitted.

[0214] Referring to FIG. 6, a third method for preparing a positive electrode composition may include a step (S1210) of preparing positive electrode active material powder and additive powder.

[0215] This method involves preparing the positive electrode active material and additives in powder form and introducing them into the slurry manufacturing step described below. Strictly speaking, unlike the first and second methods described above, the positive electrode composition in this method, in which the additive and positive electrode active material are combined, is formed during the mixing process introduced into the slurry manufacturing step.

[0216] As with the second method described above, the additive disclosed in the present invention can be understood as a method that can be attempted in that it forms a bond with the positive electrode active material through a spontaneous condensation reaction in a moisture-free environment.

[0217] In addition, the additive disclosed in the present invention can be understood as a method that can be attempted in that it is expected to have an effect of preventing deterioration of the surface of the positive electrode active material even with a content of 1 wt% or less compared to the positive electrode active material.

[0218] The detailed properties and examples of the cathode active material and additives used are the same as in the above-described examples, and duplicate descriptions will be omitted.

[0219] The next step for preparing a slurry is to prepare a slurry by adding and mixing the positive electrode composition, conductive material, binder, and solvent prepared in the previous step.

[0220] Specifically, the conductive material is not particularly limited as long as it is a conventionally known conductive material that has conductivity without maintaining chemical changes in the anode composition.

[0221] For example, conductive materials of the carbon black series such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black, conductive materials of the conductive fiber series such as carbon fiber or metal fiber, conductive materials of the metal powder series such as fluorocarbon, aluminum, and nickel powder, conductive materials of the conductive metal oxide series such as titanium oxide, and conductive materials of the polyphenylene derivative series can be used.

[0222] Next, the binder is not particularly limited as long as it is a conventionally known binder that can perform the role of holding the positive electrode active material and the conductive material.

[0223] For example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyacrylic acid (PAA), and polyamideimide (PAI) can be used.

[0224] Next, a solvent for preparing a slurry may be a conventionally known solvent such as N-methyl-2-pyrrolidone (NMP), polypyrrolidone, isopropanol, petroleum ether, tetrahydrofuran, ethyl acetate, N,N-dimethylacetamide, N,N-dimethylformamide, n-hexane, and halogenated hydrocarbons.

[0225] Next, the additive may be added in an amount of 0.1 wt% to 1 wt% relative to the positive electrode active material in the positive electrode composition, and the weight ratio of the positive electrode composition, conductive material, and binder may be such that the positive electrode composition is included in an amount of 90 wt% to 98 wt%, the conductive material is included in an amount of 1 wt% to 5 wt%, and the binder is included in an amount of 1 wt% to 5 wt%.

[0226] Hereinafter, the contents and results of an experiment performed on a lithium secondary battery positive electrode composition with a multifunctional surface degradation prevention additive added thereto, manufactured including a method for manufacturing a lithium secondary battery positive electrode composition with a multifunctional surface degradation prevention additive added thereto according to one embodiment of the present invention, and a lithium secondary battery manufactured including the same will be examined.

[0227] <Experimental Example 1> - Surface Verification Experiment

[0228] 1. Experimental method

[0229] a) (Comparative group 1 - NCM811) NCM811 (LiNi) was synthesized using a conventional method. 0.8 Co 0.1 Mn 0.1 O2) was manufactured to prepare control group 1.

[0230] b) (Experimental group 1 - TCPP / NCM811) Dissolve tetrakis(4-carboxyphenyl)porphyrin (hereinafter referred to as “TCPP”) in ethanol using a magnetic stirrer to create a solution.

[0231] NCM811 cathode material manufactured using the same synthesis method as the above comparative group 1 was added to the prepared solution and magnetic stirring was performed.

[0232] Afterwards, wash with ethanol through a centrifuge and dry in an oven to prepare experimental group 1.

[0233] c) Compare SEM and TEM images of the manufactured control group and experimental group.

[0234] 2. Experimental Results

[0235] Figure 7 is an SEM image of (a) NCM811 and (b) NCM811 with TCPP added. Figure 8 is a TEM image of NCM811 with TCPP added.

[0236] Referring to Fig. 7, it can be confirmed that TCPP binds to the transition metal on the surface of NCM811 and uniformly wraps the surface of NCM811 like a micelle structure. Referring to Fig. 8, it can be confirmed that TCPP added in an amount of 1 wt% relative to NCM811 forms a uniform layer with a thickness of approximately 15 nm around NCM811.

[0237] <Experimental Example 2> - Battery Performance Verification Experiment

[0238] 1. Experimental method

[0239] a) (Comparative group 1, experimental group 1) Prepare comparative group 1 and experimental group 1 of the aforementioned experimental example 1 in the same manner.

[0240] b) (Comparative group 2 - NiTCPP / NCM811) NiTCPP, which is Ni bound to TCPP, was dissolved in ethanol solvent using a magnetic stirrer to create a solution.

[0241] NCM811 cathode material manufactured using the same synthesis method as the above comparative group 1 was added to the prepared solution and magnetic stirring was performed.

[0242] Afterwards, wash with ethanol through a centrifuge and dry in an oven to prepare the experimental group.

[0243] c) The positive electrode active material of the above comparative group 1 and the positive electrode compositions of comparative group 2 and experimental group 1 are dissolved in an NMP solvent at a weight ratio of “positive electrode active material or positive electrode composition: conductive material: binder = 90:5:5”, and applied onto aluminum foil to manufacture a positive electrode, thereby forming a lithium metal negative electrode and a battery.

[0244] d) Confirm the initial capacity characteristics, rate characteristics, and life characteristics of the manufactured lithium secondary batteries, including Comparative Group 1, Comparative Group 2, and Experimental Group 1.

[0245] e) The initial capacity characteristics were compared by measuring the first cycle at 0.05C based on 1C (C-rate) = 200 mA / g, and the cycle characteristics were measured for 3 cycles at 0.1C based on 1C (C-rate) = 200 mA / g in the voltage range of 2.7 V to 4.3 V, and then the results at 0.5 C.

[0246] 2. Experimental Results 1 - Initial Capacity

[0247] Figure 9 shows the results of measuring the initial capacity of lithium secondary batteries manufactured including comparative group 1, comparative group 2, and experimental group 1.

[0248] Referring to Figure 9, experimental group 1 had a first cycle discharge capacity of 218.42 mAh·g at 0.05 C. -1 This was measured, and the initial capacity of experimental group 1 was approximately 25 mAh·g compared to control group 1. -1 You can see that it has increased.

[0249] 3. Experimental Results 2 - Rate Characteristics

[0250] Figure 10 shows the results of measuring the rate characteristics of lithium secondary batteries manufactured including comparative group 1, comparative group 2, and experimental group 1.

[0251] Referring to Figure 10, the discharge capacity of experimental group 1 is 128.65 mAh·g at 5C. -1 This is measured to be approximately 55 mAh·g compared to NCM811. -1 There were many, and it was confirmed that the rate characteristics were improved through this.

[0252] 4. Experimental Results 3 - Lifespan Characteristics

[0253] Figure 11 shows the results of measuring the life characteristics of lithium secondary batteries manufactured including Comparative Group 1, Comparative Group 2, and Experimental Group 1. Figure 12 shows SEM images confirming the surface and internal corrosion state of the positive electrode active material after the life characteristic test of lithium secondary batteries manufactured including Comparative Group 1, Comparative Group 2, and Experimental Group 1.

[0254] Referring to Figure 11, experimental group 1 showed a discharge capacity retention rate of 92.5% after 300 cycles, confirming a lifespan characteristic that was improved by 15% compared to comparative group 1 (77.5%), and experimental group 1 (92.5%) showed a lifespan characteristic that was improved by 54% compared to comparative group 2 (38.5%).

[0255] Referring to Fig. 12, after the battery life characteristic test, in the case of comparative group 1 (Fig. 12(a)), it was confirmed that F was unevenly distributed on the surface of the positive electrode active material and that surface corrosion had occurred, and it was also confirmed that cracks and corrosion had occurred inside the positive electrode active material.

[0256] In addition, in the case of Comparative Group 2 (Fig. 12(c)), it was confirmed that surface corrosion occurred even though F was distributed relatively uniformly on the surface of the cathode active material compared to Comparative Group 1 (Fig. 12(a)), and it was confirmed that cracks and corrosion also occurred inside the cathode active material.

[0257] Meanwhile, in the case of experimental group 1 (Fig. 12(b)), it was confirmed that F was uniformly distributed on the surface of the positive electrode active material and that surface corrosion was prevented, and it was also confirmed that cracks and corrosion were prevented inside the positive electrode active material.

[0258] Interpreting the difference in results, first of all, the types of internal corrosion include inter-granular cracks that occur when the lithium passages on the surface of the positive electrode material are blocked or the volume expansion of the particles is severe, and surface-induced cracks that progress from the surface to the inside due to hydrofluoric acid (HF). It can be understood that both inter-granular cracks and surface-induced cracks were effectively prevented in experimental group 1.

[0259] In particular, the comparison between comparative group 2, in which F was uniformly distributed on the surface of the cathode active material compared to comparative group 1, but surface corrosion was confirmed, and experimental group 1 shows that the experimental group 1 also effectively prevents surface corrosion.

[0260] <Experimental Example 3> - LFP Application Experiment

[0261] 1. Experimental method

[0262] a) (Comparison group 3 - LFP) Comparison group 3 was prepared using commercially available LFP (LiFePO4).

[0263] b) (Experimental group 2 - TCPP / LFP) Dissolve TCPP in ethanol solvent using a magnetic stirrer to make a solution.

[0264] An LFP cathode material manufactured using the same synthetic method as the comparative group 3 was added to the prepared solution and magnetic stirring was performed.

[0265] Afterwards, wash with ethanol through a centrifuge and dry in an oven to prepare experimental group 2.

[0266] c) The positive electrode active material of the comparative group 3 and the positive electrode composition of the experimental group 2 are dissolved in an NMP solvent at a weight ratio of “positive electrode active material or positive electrode composition: conductive material: binder = 90:5:5”, and applied onto aluminum foil to manufacture a positive electrode, thereby forming a battery with a lithium metal negative electrode.

[0267] d) Confirm the rate characteristics and life characteristics of the manufactured lithium secondary batteries, including comparative group 3 and experimental group 2.

[0268] e) The cycle characteristics were measured and compared for 3 cycles of 0.1C and then 1C at 1C=170 mA / g in the voltage range of 2.0 V - 4.2 V.

[0269] 2. Experimental Results 1 - Rate Characteristics

[0270] Figure 13 shows the results of measuring the rate characteristics of lithium secondary batteries manufactured including comparative group 3 and experimental group 2.

[0271] Referring to Figure 13, the discharge capacity of experimental group 2 is approximately 128 mAh·g at 5C. -1 This was measured to be approximately 5 mAh·g compared to control group 3 -1There were many, and it was confirmed that the rate characteristics were improved through this.

[0272] 3. Experimental Results 2 - Lifespan Characteristics

[0273] Figure 14 shows the results of measuring the life characteristics of lithium secondary batteries manufactured including comparative group 3 and experimental group 2.

[0274] Referring to Figure 14, after 450 cycles, experimental group 2 showed a discharge capacity retention rate of approximately 65%, confirming a lifespan characteristic that was improved by 15% compared to comparative group 3 (50%).

[0275] <Experimental Example 4> - Lifetime characteristics of lithium secondary batteries manufactured using the third positive electrode slurry manufacturing method

[0276] 1. Experimental method

[0277] a) Among the methods for manufacturing a cathode slurry for a lithium secondary battery with the aforementioned multifunctional surface degradation prevention additive, a cathode slurry was prepared using the third method, and a lithium secondary battery manufactured using the cathode slurry was prepared as experimental group 3. A lithium secondary battery manufactured using a conventional method (comparative group 4) was prepared as a comparative group. This experiment was conducted to confirm the effectiveness of the third method by comparing the life characteristics of comparative group 4 and experimental group 3.

[0278] b) The manufacturing method of (Comparative Group 4 - NCM811) is as follows:

[0279] - NCM811 (LiNi) cathode active material available on the market 0.8 Co 0.1 Mn 0.1 Prepare O2)

[0280] - Prepare a cathode slurry by dissolving the cathode active material: conductive material: binder in a weight ratio of 90:5:5 in NMP solvent.

[0281] - The manufactured positive electrode slurry is applied onto aluminum foil to manufacture a positive electrode, and combined with a lithium metal negative electrode to form a battery.

[0282] c) The manufacturing method of (Experimental Group 3 - TCPP / NCM811) is as follows:

[0283] - NCM811 (LiNi) cathode active material using conventional synthesis method 0.8 Co 0.1 Mn 0.1 O2) is manufactured and prepared in powder form.

[0284] - Prepare TCPP with additives

[0285] - The cathode active material powder, conductive agent, and binder are mixed together with additives in a weight ratio of “cathode active material: conductive agent: binder = 90:5:5” to produce cathode slurry.

[0286] - The manufactured slurry is applied onto aluminum foil to manufacture a positive electrode, and combined with a lithium metal negative electrode to form a battery.

[0287] d) Cycle characteristics were measured for lithium secondary batteries manufactured using the methods of Comparative Group 4 and Experimental Group 3. Cycle characteristics were measured and compared for 3 cycles of 0.1C and then 1C, based on 1C = 200mA / g in the voltage range of 2.7V - 4.3V.

[0288] 2. Experimental results

[0289] a) Figure 15 shows the results of measuring the life characteristics of lithium secondary batteries manufactured including comparative group 4 and experimental group 3.

[0290] b) Referring to FIG. 15, the discharge capacity retention rate of experimental group 3 after 200 cycles was approximately 60% (180 mA / g -> 110 mA / g), confirming a 15% improved life characteristic compared to comparative group 4 (approximately 45%, 180 mA / g -> 80 mA / g).

[0291] c) These results can be interpreted to indicate that the additive effectively binds to the positive electrode active material in all three methods disclosed in the present invention and can prevent surface deterioration of the positive electrode active material.

[0292] - First: A method of manufacturing a cathode composition by mixing an additive and a cathode active material in an organic solvent environment, and then manufacturing a cathode slurry by mixing the cathode composition with a conductive agent, binder, and solvent.

[0293] - Second: A method of manufacturing a cathode composition by simply mixing cathode active material powder and additives, and then manufacturing a cathode slurry by mixing the cathode composition with a conductive agent, binder, and solvent.

[0294] - Third: A method for producing a cathode slurry by directly mixing the cathode active material and additives with a conductive agent, binder, and solvent.

[0295] The foregoing description of the present invention is provided for illustrative purposes only. Those skilled in the art will readily appreciate that modifications to other specific embodiments can be made without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting.

[0296] For example, although the present invention has been described with reference to an embodiment illustrated in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and variations of the embodiments are possible from this.

[0297] Therefore, the true technical protection scope of the present invention is indicated by the technical idea of ​​the patent claims described below, and all changes or modified forms derived from the image and scope of the patent claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims

1. A cathode active material comprising a lithium transition metal oxide; and An additive having an organic skeleton and including at least one functional group capable of bonding to a transition metal atom, The above additives are, A lithium secondary battery positive electrode composition with a multifunctional surface degradation prevention additive added, characterized in that the functional group binds to a transition metal atom present on the surface of the positive electrode active material and inhibits the transition metal atom from moving within the lithium transition metal oxide lattice.

2. In paragraph 1, The above functional group is, A positive electrode composition for a lithium secondary battery, comprising a multifunctional surface degradation prevention additive characterized by bonding with a transition metal atom through a condensation reaction.

3. In paragraph 2, The above organic skeleton is sp 2 A positive electrode composition for a lithium secondary battery, characterized in that it contains carbon and has a multifunctional surface degradation prevention additive added thereto.

4. In paragraph 2 or 3, A positive electrode composition for a lithium secondary battery, characterized in that the organic skeleton includes a non-covalent electron, and to which a multifunctional surface degradation prevention additive is added.

5. In paragraph 2, A lithium secondary battery positive electrode composition with a multifunctional surface deterioration prevention additive, characterized in that the positive electrode active material comprises at least one of the positive electrode active materials represented by the following chemical formulas 1 to 5: [Chemical Formula 1] LiCoO2 [Chemical Formula 2] LiNi 1-x-y Co x Mr y O2 In the above chemical formula 2, 0 <x≤0.2, 0<y≤0.2이다. [Chemical Formula 3] LiMaPO4 In the above chemical formula 3, Ma is one or more elements selected from Fe, Co, Ni, and Mn. [Chemical Formula 4] LiMb2O4 In the above chemical formula 4, Mb is one or more elements selected from Mn, Ni, and Co. [Chemical Formula 5] Li a M' b M'' c M''' d O2 In the above chemical formula 5, each of M', M'', and M''' may be one or more elements selected from Fe, Co, Ni, and Mn. In the above chemical formula 5, 1 <a, (a-1)+b+c+d=1일 수 있다.

6. In paragraph 4, The above organic skeleton includes a porphyrin-based organic substance, A lithium secondary battery positive electrode composition with a multifunctional surface deterioration prevention additive added, characterized in that the functional group includes at least one selected from the group consisting of a hydroxyl group (-OH), a carboxyl group (-COOH), a sulfonic acid group (-SO3H), and combinations thereof.

7. [Revised on 12.09.2025 by Article 91 of the Rules] In paragraph 4, the additive is characterized in that it includes at least one of the compounds represented by the following chemical formulas 6 to 17, wherein a positive electrode composition for a lithium secondary battery is added with a multifunctional surface deterioration prevention additive: [Chemical Formula 6] [Chemical Formula 7] [Chemical Formula 8] [Chemical Formula 9] [Chemical Formula 10] [Chemical Formula 11] [Chemical Formula 12] [Chemical Formula 13] [Chemical Formula 14] [Chemical Formula 15] [Chemical Formula 16] [Chemical Formula 17] 8. In paragraph 1, A lithium secondary battery positive electrode composition with a multifunctional surface deterioration prevention additive, characterized in that the additive is added in an amount of 1 wt% or less relative to the positive electrode active material.

9. A positive electrode for a lithium secondary battery, comprising a positive electrode composition for a lithium secondary battery to which a multifunctional surface deterioration prevention additive according to Article 1 is added.

10. A lithium secondary battery comprising a positive electrode for a lithium secondary battery according to Article 9.

11. A step of mixing a cathode active material including a lithium transition metal oxide and an additive in an organic solvent environment; a step of performing centrifugation; and Includes a drying step in an oven, The above additives are, organic skeleton; and A method for producing a positive electrode composition for a lithium secondary battery, wherein a multifunctional surface degradation prevention additive is added, characterized in that it contains at least one functional group capable of bonding with a transition metal atom.

12. In paragraph 11, The above mixing step is, A method for producing a positive electrode composition for a lithium secondary battery, characterized in that the positive electrode composition is prepared by adding a multifunctional surface degradation prevention additive, and is performed at a temperature of 10°C to 80°C.

13. In paragraph 11, The above functional group is, A method for producing a positive electrode composition for a lithium secondary battery, to which a multifunctional surface degradation prevention additive is added, characterized in that it combines with a transition metal atom through a condensation reaction.

14. In paragraph 13, The above organic skeleton is sp 2 A method for producing a positive electrode composition for a lithium secondary battery, wherein a multifunctional surface degradation prevention additive is added, characterized in that it contains carbon.

15. In paragraph 13 or 14, A method for producing a positive electrode composition for a lithium secondary battery, wherein the organic skeleton includes a non-covalent electron and a multifunctional surface degradation prevention additive is added.

16. In paragraph 13, A method for manufacturing a positive electrode composition for a lithium secondary battery with a multifunctional surface deterioration prevention additive, characterized in that the positive electrode active material comprises at least one of the positive electrode active materials represented by the following chemical formulas 1 to 5: [Chemical Formula 1] LiCoO2 [Chemical Formula 2] LiNi 1-x-y Co x Mr y O2 In the above chemical formula 2, 0 <x≤0.2, 0<y≤0.2이다. [Chemical Formula 3] LiMaPO4 In the above chemical formula 3, Ma is one or more elements selected from Fe, Co, Ni, and Mn. [Chemical Formula 4] LiMb2O4 In the above chemical formula 4, Mb is one or more elements selected from Mn, Ni, and Co. [Chemical Formula 5] Li a M' b M'' c M''' d O2 In the above chemical formula 5, each of M', M'', and M''' may be one or more elements selected from Fe, Co, Ni, and Mn. In the above chemical formula 5, 1 <a, (a-1)+b+c+d=1일 수 있다.

17. In paragraph 15, The above organic skeleton includes a porphyrin-based organic substance, A method for producing a positive electrode composition for a lithium secondary battery, wherein the functional group includes at least one selected from the group consisting of a hydroxyl group (-OH), a carboxyl group (-COOH), a sulfonic acid group (-SO3H), and a combination thereof, and a multifunctional surface deterioration prevention additive is added.

18. [Revised on 12.09.2025 by Article 91 of the Rules] A method for producing a positive electrode composition for a lithium secondary battery with a multifunctional surface deterioration prevention additive added, characterized in that the additive comprises at least one of the compounds represented by the following chemical formulas 6 to 17: [Chemical Formula 6] [Chemical Formula 7] [Chemical Formula 8] [Chemical Formula 9] [Chemical Formula 10] [Chemical Formula 11] [Chemical Formula 12] [Chemical Formula 13] [Chemical Formula 14] [Chemical Formula 15] [Chemical Formula 16] [Chemical Formula 17] 19. A step of preparing a cathode composition including a cathode active material including a lithium transition metal oxide and an additive; It comprises a step of preparing a slurry by mixing the above positive electrode composition with a conductive material, a binder, and a solvent, The above additives are, organic skeleton; and A method for producing a positive electrode slurry for a lithium secondary battery, wherein a multifunctional surface degradation prevention additive is added, characterized in that it contains at least one functional group capable of bonding with a transition metal atom.

20. In paragraph 19, The step of preparing the above bipolar composition is: A step of mixing the positive electrode active material including the lithium transition metal oxide and the additive in an organic solvent environment; a step of performing centrifugation; and A method for producing a positive electrode slurry for a lithium secondary battery, comprising adding a multifunctional surface degradation prevention additive, characterized in that it includes a drying step in an oven.

21. In paragraph 19, The step of preparing the above bipolar composition is: A step of preparing a cathode active material powder containing a lithium transition metal oxide; and A method for producing a cathode slurry for a lithium secondary battery, characterized in that it comprises a step of mixing the cathode active material powder and an additive, and has a multifunctional surface deterioration prevention additive added thereto.

22. In paragraph 20, The above mixing step is, A method for producing a positive electrode slurry for a lithium secondary battery, characterized in that it is performed at 5°C to 80°C and has a multifunctional surface degradation prevention additive added thereto.

23. In paragraph 19, The above functional group is, A method for producing a cathode slurry for a lithium secondary battery, wherein a multifunctional surface degradation prevention additive is added, characterized in that it combines with a transition metal atom through a condensation reaction.

24. In paragraph 23, The above organic skeleton is sp 2 A method for producing a positive electrode slurry for a lithium secondary battery, wherein a multifunctional surface degradation prevention additive is added, characterized in that it contains carbon.

25. In paragraph 23 or 24, A method for producing a positive electrode slurry for a lithium secondary battery, wherein the organic skeleton includes a non-covalent electron and a multifunctional surface degradation prevention additive is added.

26. In paragraph 23, A method for manufacturing a cathode slurry for a lithium secondary battery with a multifunctional surface deterioration prevention additive, characterized in that the cathode active material comprises at least one of the cathode active materials represented by the following chemical formulas 1 to 5: [Chemical Formula 1] LiCoO2 [Chemical Formula 2] LiNi 1-x-y Co x Mr y O2 In the above chemical formula 2, 0 <x≤0.2, 0<y≤0.2이다. [Chemical Formula 3] LiMaPO4 In the above chemical formula 3, Ma is one or more elements selected from Fe, Co, Ni, and Mn. [Chemical Formula 4] LiMb2O4 In the above chemical formula 4, Mb is one or more elements selected from Mn, Ni, and Co. [Chemical Formula 5] Li a M' b M'' c M''' d O2 In the above chemical formula 5, each of M', M'', and M''' may be one or more elements selected from Fe, Co, Ni, and Mn. In the above chemical formula 5, 1 <a, (a-1)+b+c+d=1일 수 있다.

27. In paragraph 25, The above organic skeleton includes a porphyrin-based organic substance, A method for producing a positive electrode slurry for a lithium secondary battery, wherein the functional group comprises at least one selected from the group consisting of a hydroxyl group (-OH), a carboxyl group (-COOH), a sulfonic acid group (-SO3H), and a combination thereof, and a multifunctional surface deterioration prevention additive is added.

28. [Correction pursuant to Rule 91 12.

09. [2025] In the 25th paragraph, a method for manufacturing a positive electrode slurry for a lithium secondary battery with a multifunctional surface deterioration prevention additive added, characterized in that the additive comprises at least one of the compounds represented by the following chemical formulas 6 to 17: [Chemical Formula 6] [Chemical Formula 7] [Chemical Formula 8] [Chemical Formula 9] [Chemical Formula 10] [Chemical Formula 11] [Chemical Formula 12] [Chemical Formula 13] [Chemical Formula 14] [Chemical Formula 15] [Chemical Formula 16] [Chemical Formula 17]

Images