Positive active material composition rich in lithium and manganese

Abstract

The present disclosure provides a positive active material composition rich in lithium and manganese. The positive electrode active material may include a compound represented by Formula 1 or Formula 2: Li < 1.10 > Mn < 0.52 > Ni (0.38-x) A (x-a) MaO < 2 > (1), Li < 1.12 > Mn < 0.51 > Ni (0.37-x) A (x-a) MaO < 2 > (2). A is Co, Cr, or a combination thereof, M is W + 6, Ta + 5, V + 5, or a combination thereof, 0 < x < 0.1, 0 < a < 0.04, and 3.8 < average oxidation state of Mn ions < 4.0.

Description

Technical Field

[0001] In at least one aspect, there is provided a positive electrode active material for a lithium ion battery. Background Art

[0002] Compared with currently used nickel cobalt manganese and nickel cobalt aluminum materials, lithium and manganese rich (LMR) positive electrode active materials are considered promising next-generation cathode materials due to their weight energy density. Inherent problems of LMR, such as voltage decay during cycling, rate capacity, cycle performance, and volume energy density, have hindered widespread commercialization. Summary of the Invention

[0003] In at least one aspect, there is provided a positive electrode active material. The positive electrode active material includes a compound represented by Formula 1:

[0004] Li 1.10 Mn 0.52 Ni (0.38-x) A (x-a) M a O2 (1)

[0005] where A is Co, Cr, or a combination thereof, M is W +6 , Ta +5 , V +5 or a combination thereof, 0 < x < 0.06, 0 < a < 0.02, and 3.9 ≤ average oxidation state of Mn ions < 4.0.

[0006] In another aspect, there is provided a positive electrode active material. The positive electrode active material includes a compound represented by Formula 2:

[0007] Li 1.12 Mn 0.51 Ni (0.37-x) A (x-a) M a O2 (2)

[0008] where A is Co, Cr, or a combination thereof, M is W +6 , Ta +5 , V +5 or a combination thereof, 0 < x < 0.1, 0 < a < 0.04, and 3.8 < average oxidation state of Mn ions < 4.0.

[0009] In another aspect, there is provided a rechargeable lithium ion battery including at least one lithium ion battery cell. Each lithium ion battery cell includes a positive electrode (which includes a compound represented by Formula 1 or Formula 2), a negative electrode including a negative electrode active material, and an electrolyte in contact with the positive electrode and the negative electrode.

[0010] Advantageously, the positive electrode active material is composed of a material having a lower average Mn oxidation state (i.e., a higher amount of Mn in the composition) than the positive electrode active materials of the prior art. +3 In addition, when the Ni and Li contents are the same as those of the positive electrode active material in the prior art, this new LMR composition can also have a lower Co content. +3 and lower Li + The compositions may alleviate issues with LMR, such as voltage fade during cycling, rate capability, cycling performance, and / or lower volumetric energy density.

[0011] On the other hand, the cathode materials provided herein minimize the energy density reduction while alleviating other inherent issues such as voltage decay during cycling, rate compatibility, and cycling performance.

[0012] The foregoing summary is illustrative only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1A is a schematic cross-section of a positive electrode including cathode active material on a single side of a current collector.

[0014] Figure 1B is a schematic cross-section of a positive electrode including cathode active material on both sides of a current collector.

[0015] Figure 2 It is a general curve graph of voltage and capacity.

[0016] Figure 3 Yes Figure 1A Schematic cross section of a battery cell with a positive electrode.

[0017] Figure 4 Yes Figure 2 Schematic cross section of a battery pack of battery cells. DETAILED DESCRIPTION

[0018] As required, detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the present invention that can be implemented in various forms and alternative forms. The drawings are not necessarily drawn to scale; some features may be enlarged or minimized to show details of specific components. Therefore, the specific structural details and functional details disclosed herein are not to be interpreted as limiting, but only as a representative basis for teaching those skilled in the art to adopt the present invention in various ways.

[0019] Unless in the examples or where otherwise expressly indicated, all numerical quantities in this specification indicating amounts of materials or conditions of reaction and / or use should be understood as modified by the word "about" to describe the broadest scope of the invention. Practice within the stated numerical limits is generally preferred. Furthermore, unless expressly stated to the contrary, when a given chemical structure includes a substituent on a chemical moiety (e.g., on an aryl, alkyl, etc.), the substituent is attributed to a more general chemical structure that comprises the given structure; otherwise, percentages, "parts," and ratio values ​​are by weight; the term "polymer" includes "oligomers," "copolymers," "terpolymers," and the like; molecular weights provided for any polymer refer to weight average molecular weights unless otherwise indicated; description of a group or class of materials as suitable or preferred for a given purpose in conjunction with the present invention implies that mixtures of any two or more of the members of the group or class are equally suitable or preferred; description of ingredients in chemical terms refers to the ingredients when added to any combination specified in the specification, and does not necessarily exclude chemical interactions between the ingredients of the mixture once mixed; the first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation herein and applies mutatis mutandis to normal grammatical variations of the initially defined abbreviation; and, unless expressly stated to the contrary, measurements of properties are determined by the same techniques as previously or later mentioned for the same property.

[0020] It must also be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to a component in the singular is intended to include a plurality of components.

[0021] It must also be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to a component in the singular is intended to include a plurality of components.

[0022] As used herein, the term "about" means that the amount or value in question can be the specified specific value or some other value in its neighborhood. Typically, the term "about" indicating a value is intended to indicate a range within + / - 5% of the value. As an example, the phrase "about 100" indicates a range of 100+ / - 5, i.e., a range of 95 to 105. Typically, when the term "about" is used, it is expected that similar results or effects according to the present invention can be obtained within a range of + / - 5% of the indicated value.

[0023] As used herein, the term "and / or" means that all or only one of the elements of the group may be present. For example, "A and / or B" shall mean "only A or only B, or both A and B". In the case of "only A", the term also covers the possibility that B is not present, i.e., "only A, but no B".

[0024] It should also be understood that the present invention is not limited to the specific embodiments and methods described below, as specific components and / or conditions may vary of course. In addition, the terminology used herein is only used to describe the purpose of specific embodiments of the present invention, and is not intended to be limiting in any way.

[0025] The term "comprising" is synonymous with "including," "having," "containing," or "characterized by." These terms are inclusive and open-ended and do not exclude additional, unrecited elements or method steps.

[0026] The phrase "consisting of" excludes any element, step, or ingredient not specified in the claim. When the phrase appears in a clause in the body of a claim, rather than immediately following the preamble, it limits only the elements set forth in that clause; the entire claim does not exclude other elements.

[0027] The phrase "consisting essentially of" limits the scope of a claim to the specified materials or steps, plus those that do not materially affect one or more of the basic and novel characteristics of the claimed subject matter.

[0028] The phrase “consisting of means “including” or “composed of.” Generally, the phrase is used to indicate that an object is formed of a material.

[0029] With respect to the terms "comprising," "consisting of," and "consisting essentially of," where one of these three terms is used herein, the presently disclosed and claimed subject matter may include the use of either of the other two terms.

[0030] The term "one or more" means "at least one", and the term "at least one" means "one or more". The terms "one or more" and "at least one" include "plurality" and "multiple" as subsets. In a refinement, "one or more" includes "two or more".

[0031] The terms "substantially," "generally," or "about" may be used herein to describe the disclosed or claimed embodiments. The term "substantially" may modify a value or relative property disclosed or claimed in the present disclosure. In such instances, "substantially" may mean that the value or relative property it modifies is within ±0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, or 10% of the value or relative property.

[0032] It should also be understood that integer ranges explicitly include all intermediate integers. For example, the integer range 1 to 10 explicitly includes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Similarly, the range 1 to 100 includes 1, 2, 3, 4, ..., 97, 98, 99, 100. Similarly, when any range is required, the intermediate values ​​that are the difference between the upper and lower limits divided by the increment of 10 can be considered as alternative upper or lower limits. For example, if the range is 1.1 to 2.1, the following values ​​1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0 can be selected as lower or upper limits.

[0033] When referring to a numerical quantity, in one refinement, the term "less than" includes a non-inclusive lower limit that is 5% of the number indicated after "less than." For example, in one refinement, "less than 20" includes a non-inclusive lower limit of 1. Thus, this refinement of "less than 20" includes a range between 1 and 20. In another refinement, the term "less than" includes a non-inclusive lower limit that is, in ascending order of priority, 20%, 10%, 5%, or 1% of the number indicated after "less than."

[0034] The term "positive electrode" means the cell electrode from which current flows when a lithium-ion cell or battery is discharged. Sometimes, the "positive electrode" is referred to as the "cathode."

[0035] The term "negative electrode" refers to the battery cell electrode into which current flows when the lithium-ion battery cell is discharged. Sometimes, the "negative electrode" is called the "anode."

[0036] The term "cell" or "battery cell" means an electrochemical unit made of at least one positive electrode, at least one negative electrode, an electrolyte, and a separator.

[0037] The term "battery" or "battery pack" means an electrical storage device made of at least one battery cell. In a refinement, a "battery" or "battery pack" is an electrical storage device made of a plurality of battery cells.

[0038] The term "specific capacity" refers to the capacity per unit mass of the cathode or anode active material. The unit of specific capacity is milliampere-hour per gram (mAh / g).

[0039] Abbreviations:

[0040] "LMR" stands for lithium and manganese rich layered oxide.

[0041] "mAh" stands for milliampere-hour.

[0042] "mAh / g" means milliampere-hours per gram.

[0043] Reference Figure 1A and Figure 1B provide a schematic view of a positive electrode including a positive electrode active material. The positive electrode 10 includes a positive electrode active material layer 12 disposed above and generally in contact with the positive electrode current collector 14. Generally, the positive electrode current collector 14 is a metal plate or metal foil made of a metal such as aluminum, copper, platinum, zinc, titanium, etc. Currently, aluminum is most commonly used for the positive electrode current collector. The positive electrode active material is represented by Formula 1:

[0044] Li 1.10 Mn 0.52 Ni (0.38-x) A (x-a) M a O2 (1)

[0045] Wherein:

[0046] A is Co, Cr, or a combination thereof;

[0047] M is W+6, Ta+5, V+5, or a combination thereof;

[0048] 0 < x < 0.06;

[0049] 0 < a < 0.02; and

[0050] 3.9 ≤ average oxidation state of Mn ions < 4.0.

[0051] Figure 1A shows a positive electrode including a positive electrode active material on one side of the current collector, while Figure 1B shows a positive electrode including a positive electrode active material on both sides of the current collector.

[0052] In one variant, 0.01 < x < 0.04. In an improved embodiment, x is at least 0, 0.005, or 0.01 in ascending order of priority, and at most 0.06, 0.05, or 0.04 in ascending order of priority.

[0053] In one variant, 0 < a ≤ 0.01. In an improved embodiment, x is at least 0, 0.001, or 0.002 in ascending order of priority, and at most 0.02, 0.015, or 0.01 in ascending order of priority.

[0054] In one variant, the average oxidation state of Mn ions is 3.94 to 3.98. In an improved embodiment, the average oxidation state of the ions is at least 3.9, 3.92, or 3.94 in ascending order of priority, and at most 4, 3.99, or 3.98 in ascending order of priority.

[0055] Figure 2A total curve graph of voltage and capacity is provided. Generally, it is desirable to maximize the slope region and minimize the plateau region. This can be achieved by increasing the incorporation of Mn +3 to obtain a maximized slope region. This can be achieved by incorporating hexavalent and pentavalent dopant ions into the positive electrode active material. The hexavalent and pentavalent dopant ions include W +6 , Ta +5 , and V +5 . The larger ionic sizes of W +6 and Ta +5 can result in better rate capacity, and Mn +3 results in better electronic conductivity.

[0056] In one variant, the Mn in Formula 1 includes Mn with an oxidation value of +3 and Mn with an oxidation value of +4. In another variant, the positive electrode active material of Formula 1 has an average oxidation state of Ni ions of approximately 2. Specific positive electrode active materials are provided in Table 1.

[0057] Table 1. Positive Electrode Active Material Composition of Formula 1

[0058]

[0059] It is observed that these materials have an average oxidation state of Ni ions of approximately 2.

[0060] In one variant, the positive electrode active material is represented by Formula 2:

[0061] Li 1.12 Mn 0.51 Ni (0.37-x) A (x-a) M a O2 (2)

[0062] Where:

[0063] A is Co, Cr, or a combination thereof;

[0064] M is W +6 , Ta +5 , V +5 , or a combination thereof;

[0065] 0 < x < 0.1;

[0066] 0 < a < 0.04; and

[0067] 3.8 < average oxidation state of Mn ions < 4.0.

[0068] In one variant, 0.02 < x < 0.09. In an improved scheme, x is at least 0, 0.01, or 0.02 in ascending order of priority, and at most 0.1, 0.095, or 0.09 in ascending order of priority.

[0069] In one variant, 0<a≤0.03. In one refinement, a is at least 0, 0.001 or 0.0015 in increasing order of preference, and at most 0.04, 0.035 or 0.03 in increasing order of preference.

[0070] In one variation, the average oxidation state of the Mn ions is 3.86 to 3.98. In one refinement, the average oxidation state of the ions is at least 3.8, 3.82, 3.84, or 3.86 in increasing order of preference, and at most 4, 3.99, or 3.98 in increasing order of preference.

[0071] In one variation, the Mn in Formula 2 includes Mn with an oxidation number of +3 and Mn with an oxidation number of +4. In another variation, the positive active material of Formula 2 has an average oxidation state of Ni ions of about 2. Specific positive active materials are provided in Table 2.

[0072] Table 2. Positive electrode active material composition of Formula 2

[0073]

[0074] These materials were observed to have an average oxidation state of the Ni ions of about 2.

[0075] refer to Figure 3 , a schematic diagram of a rechargeable lithium-ion battery cell incorporating the positive electrode of FIG. 1 is provided. The battery cell 20 includes a positive electrode 10 as described above, a negative electrode 22, and a separator 24 interposed between the positive electrode and the negative electrode. The negative electrode 22 includes a negative electrode collector 26 and a negative electrode active material layer 28 disposed above the negative electrode collector and generally in contact with the negative electrode collector. Typically, the negative electrode collector 26 is a metal plate or metal foil composed of a metal such as aluminum, copper, platinum, zinc, titanium, etc. At present, copper is most commonly used for the negative electrode collector. The battery cell 20 is immersed in an electrolyte 30 enclosed by a battery cell housing 32. The electrolyte 30 is absorbed into the separator 24. In other words, the separator 24 includes an electrolyte 30, thereby allowing lithium ions to move between the negative electrode 22 and the positive electrode 10. The electrolyte 30 includes a non-aqueous organic solvent and a lithium salt. The non-aqueous organic solvent is used as a medium for transmitting ions participating in the electrochemical reaction. Advantageously, battery cell 20 may have a cathode specific capacity greater than 200 mAh / g at 0.1°C.

[0076] refer to Figure 4 , providing a positive electrode and Figure 3 A schematic diagram of a rechargeable lithium-ion battery having a battery cell. The rechargeable lithium-ion battery 40 includes Figure 3 Typically, the rechargeable lithium-ion battery 40 includes Figure 3 At least one battery cell 20 of the design iEach lithium-ion battery cell has 20 i The invention comprises: a positive electrode 10 including a compound represented by Formula 1 or Formula 2; a negative electrode 22 including a negative electrode active material; and an electrolyte 30, wherein i is an integer mark for each battery cell. The mark i is from 1 to nmax, wherein nmax is the total number of battery cells in the rechargeable lithium ion battery 40. The electrolyte 30 includes a non-aqueous organic solvent and a lithium salt. The non-aqueous organic solvent is used as a medium for transporting ions participating in the electrochemical reaction. A plurality of battery cells may be connected in series, in parallel, and / or in combination thereof. A voltage output from the battery 40 is provided across terminals 42 and 44. Advantageously, the rechargeable lithium ion battery 40 may have a cathode specific capacity greater than 200 mAh / g at 0.1°C for each battery cell therein.

[0077] refer to Figure 3 and Figure 4 The separator 24 physically separates the negative electrode 22 from the positive electrode 10, thereby preventing short circuits while allowing lithium ions to be transported for charging and discharging. Therefore, the separator 24 can be made of any material suitable for this purpose. Examples of suitable materials that can constitute the separator 24 include, but are not limited to, polytetrafluoroethylene (e.g., ), fiberglass, polyester, polyethylene, polypropylene, and combinations thereof. The separator 24 may be in the form of a woven fabric or a nonwoven fabric. For example, polyolefin-based polymer separators such as polyethylene and / or polypropylene are commonly used in lithium-ion batteries. In order to ensure heat resistance or mechanical strength, a coated separator including a ceramic or polymer material coating may be used.

[0078] The electrolyte 30 includes a lithium salt dissolved in a non-aqueous organic solvent. Therefore, the electrolyte 30 includes lithium ions, which can be embedded in the positive electrode active material during charging and embedded in the anode active material during discharging. Examples of lithium salts include, but are not limited to, LiPF6, LiBF4, LiSbF6, LiAsF6, LiC4F9SO3, LiClO4, LiAlO2, LiAlCl4, LiCl, LiI, LiB(C2O4)2, and combinations thereof. In a refinement, the electrolyte includes a lithium salt in an amount of about 0.1M to about 2.0M.

[0079] Electrolyte 30 may include a non-aqueous organic solvent and a lithium salt. Advantageously, the non-aqueous organic solvent is used as a medium for transporting ions and in particular lithium ions participating in the electrochemical reaction. Suitable non-aqueous organic solvents include carbonate-based solvents, ester-based solvents, ether-based solvents, ketone-based solvents, alcohol-based solvents, aprotic solvents, and combinations thereof. Examples of carbonate-based solvents include, but are not limited to, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methylethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, and combinations thereof. Examples of ester-based solvents include, but are not limited to, methyl acetate, ethyl acetate, n-propyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, decanolactone, valerolactone, mevalonolactone, caprolactone, and combinations thereof. Examples of ether-based solvents include, but are not limited to, dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethoxyethane, 2-methyltetrahydrofuran, tetrahydrofuran, and the like, and ketone-based solvents may include cyclohexanone, and the like. Examples of alcohol-based solvents include, but are not limited to, methanol, ethanol, n-propanol, isopropanol, etc. Examples of aprotic solvents include, but are not limited to, nitriles such as R-CN (wherein R is a C2-20 straight, branched or cyclic hydrocarbon, which may include a double bond, an aromatic ring or an ether bond), amides such as dimethylformamide, dioxolanes such as 1,3-dioxolanes, cyclopentane, etc. Advantageously, non-aqueous organic solvents may be used alone. In other variations, a mixture of non-aqueous organic solvents may be used. Such mixtures are generally formulated to optimize battery performance. In an improved embodiment, carbonate-based solvents are prepared by mixing cyclic carbonates and linear carbonates. In one variation, the electrolyte 30 may also include a vinylene carbonate-based or ethylene carbonate-based compound to extend the battery cycle life.

[0080] The negative electrode 22 and the positive electrode 10 can be made by methods known to those skilled in the art of lithium-ion batteries. Typically, an active material (e.g., a positive electrode or a negative electrode active material) is mixed with a conductive material and a binder in a solvent (e.g., N-methylpyrrolidone) into an active material composition and the composition is coated on a current collector. Electrode manufacturing methods are well known and therefore are not described in detail in this specification. The solvent includes N-methylpyrrolidone and the like, but is not limited thereto.

[0081] The positive electrode active material layer 12 includes a positive electrode active material represented by Formula 1 or Formula 2, a binder, and a conductive material. The binder can increase the bonding properties of the positive electrode active material particles to each other and to the positive electrode current collector 14. Examples of suitable binders include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene butadiene rubber, acrylate styrene butadiene rubber, epoxy resin, nylon, etc., and combinations thereof. The conductive material provides conductivity to the positive electrode 10. Examples of suitable conductive materials include, but are not limited to, natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, copper, metal powder, metal fiber, and combinations thereof. Examples of metal powders and metal fibers include nickel, aluminum, silver, and the like.

[0082] The negative electrode active material layer 26 includes a negative electrode active material, a binder, and optionally a conductive material. The negative electrode active materials used herein may be those known to those skilled in the art of lithium ion batteries. The negative electrode active materials include, but are not limited to, carbon-based negative electrode active materials, silicon-based negative electrode active materials, and combinations thereof. Suitable carbon-based negative electrode active materials may include graphite and graphene. Suitable silicon-based negative electrode active materials may include at least one selected from silicon, silicon oxide, silicon oxide coated with conductive carbon on the surface, and silicon coated with conductive carbon on the surface. For example, silicon oxide may be of the formula SiO z Description, wherein z is 0.09 to 1.1. A mixture of a carbon-based negative electrode active material and a silicon-based negative electrode active material can also be used for the negative electrode active material.

[0083] The negative electrode binder increases the bonding properties of the negative electrode active material particles to each other and to the current collector. The binder can be a non-aqueous binder, an aqueous binder, or a combination thereof. Examples of non-aqueous binders can be polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or a combination thereof. The aqueous binder can be a rubber-based binder or a polymer resin binder. Examples of rubber-based binders include, but are not limited to, styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluororubber, and combinations thereof. Examples of polymer resin binders include, but are not limited to, polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene oxide, polyvinyl pyrrolidone, epichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, ethylene-propylene-diene copolymer, polyvinyl pyridine, chlorosulfonated polyethylene, latex, polyester resin, acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0084] While the above describes exemplary embodiments, these embodiments are not intended to describe all possible forms of the invention. Rather, the words used in the specification are descriptive words rather than limiting words, and it is to be understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of the various embodiments may be combined to form further embodiments of the invention.

[0085] According to the present invention, there is provided a positive electrode active material having a compound represented by Formula 1: Li 1.10 Mn 0.52 Ni (0.38-x) A (x-a) M a O2 (1), wherein:

[0086] A is Co, Cr, or a combination thereof;

[0087] M is W +6 、Ta +5 、V +5 or a combination thereof;

[0088] 0 < x < 0.06;

[0089] 0 < a < 0.02; and

[0090] 3.9 ≤ average oxidation state of Mn ions < 4.0.

[0091] According to an embodiment, 0.01 < x < 0.04.

[0092] According to an embodiment, 0 < a ≤ 0.01.

[0093] According to an embodiment, 3.94 ≤ average oxidation state of Mn ions ≤ 3.98.

[0094] According to an embodiment, the present invention is further characterized by a material selected from the group consisting of: Li 1.10 Mn 0.52 Ni 0.33 Co 0.04 W 0.01 O2, Li 1.10 Mn 0.52 Ni 0.33 Co 0.04 Ta 0.01 O2, Li 1.10 Mn 0.52 Ni 0.33 Co 0.04 V 0.01 O2, Li 1.10 Mn 0.52 Ni 0.33 Co 0.03 W 0.02O2, Li 1.10 Mn 0.52 Ni 0.33 Co 0.03 Ta 0.02 O2 and Li 1.10 Mn 0.52 Ni 0.33 Co 0.03 V 0.02 O2.

[0095] According to an embodiment, the Ni has an average oxidation state of about 2.

[0096] According to the present invention, there is provided a positive electrode active material having a compound represented by Formula 2: Li 1.12 Mn 0.51 Ni (0.37-x) A (x-a) M a O2 (2), wherein:

[0097] A is Co, Cr, or a combination thereof;

[0098] M is W +6 , Ta +5 , V +5 , or a combination thereof;

[0099] 0 < x < 0.1;

[0100] 0 < a < 0.04; and

[0101] 3.8 < average oxidation state of Mn ions < 4.0.

[0102] According to an embodiment, 0.02 < x < 0.09.

[0103] According to an embodiment, 0 < a ≤ 0.03.

[0104] According to an embodiment, 3.86 ≤ average oxidation state of Mn ions ≤ 3.98.

[0105] According to an embodiment, the present invention is further characterized by a material selected from the group consisting of: Li 1.12 Mn 0.51 Ni 0.29 Co 0.065 W 0.015 O2, Li 1.12 Mn 0.51 Ni 0.29 Co 0.065 Ta 0.015 O2, Li 1.12 Mn 0.51 Ni 0.29 Co 0.065 V 0.015O2, Li 1.12 Mn 0.51 Ni 0.29 Co 0.05 W 0.03 O2, Li 1.12 Mn 0.51 Ni 0.29 Co 0.05 Ta 0.03 O2 and Li 1.12 Mn 0.51 Ni 0.29 Co 0.05 V 0.03 O2.

[0106] According to the embodiment, the Ni has an average oxidation state of about 2.

[0107] According to the present invention, there is provided a rechargeable lithium-ion battery having at least one lithium-ion battery cell, each lithium-ion battery cell comprising: a positive electrode including a compound represented by Formula 1 or Formula 2:

[0108] Li 1.10 Mn 0.52 Ni (0.38-x) A (x-a) M a O2 (1)

[0109] Li 1.12 Mn 0.51 Ni (0.37-x) A (x-a) M a O2 (2)

[0110] Wherein:

[0111] A is Co, Cr or a combination thereof,

[0112] M is W +6 , Ta +5 , V +5 or a combination thereof,

[0113] 0 < x < 0.1,

[0114] 0 < a < 0.04, and

[0115] 3.8 < average oxidation state of Mn ions < 4.0;

[0116] a negative electrode including a negative electrode active material; and

[0117] an electrolyte contacting the positive electrode and the negative electrode.

[0118] According to the embodiment, 0.01 < x < 0.09.

[0119] According to an embodiment, 0<a≤0.03.

[0120] According to an embodiment, 3.86≤the average oxidation state of the Mn ions≤3.98.

[0121] According to an embodiment, the present invention is also characterized by a material selected from the group consisting of: Li 1.10 Mn 0.52 Ni 0.33 Co 0.04 W 0.01 O2、Li 1.10 Mn 0.52 Ni 0.33 Co 0.04 Ta 0.01 O2、Li 1.10 Mn 0.52 Ni 0.33 Co 0.04 V 0.01 O2、Li 1.10 Mn 0.52 Ni 0.33 Co 0.03 W 0.02 O2、Li 1.10 Mn 0.52 Ni 0.33 Co 0.03 Ta 0.02 O2、Li 1.10 Mn 0.52 Ni 0.33 Co 0.03 V 0.02 O2、Li 1.12 Mn 0.51 Ni 0.29 Co 0.065 W 0.015 O2、Li 1.12 Mn 0.51 Ni 0.29 Co 0.065 Ta 0.015 O2、Li 1.12 Mn 0.51 Ni 0.29 Co 0.065 V 0.01 5O2、Li 1.12 Mn 0.51 Ni 0.29 Co 0.05 W 0.03 O2、Li 1.12 Mn 0.51 Ni 0.29 Co 0.05 Ta 0.03 O2 and Li1.12 Mn 0.51 Ni 0.29 Co 0.05 V 0.03 O2.

[0122] According to an embodiment, each battery cell further includes a separator interposed between the positive electrode and the negative electrode.

[0123] According to an embodiment, the Ni has an average oxidation state of about 2.

Claims

1. A positive electrode active material, which comprises a compound represented by Formula 1: Li 1.10 Mr 0.52 Ni (0.38-x) Co (x-a) M a O2 (1) Wherein: M is for W +6 、 +5 、V +5 or a combination thereof; 0<x<0.06； 0 < a < 0.02; and 3.9 < average oxidation state of Mn ions < 4.

0.

2. The positive electrode active material according to claim 1, wherein 0.001 < x < 0.

055.

3. The positive electrode active material according to claim 1, wherein 0.01 < a < 0.

02.

4. The positive electrode active material according to claim 1, wherein 3.92 < average oxidation state of Mn ions < 3.

98.

5. The positive electrode active material according to claim 1, comprising a material selected from the group consisting of: Li 1.10 Mn 0.52 Ni 0.33 Co 0.04 W 0.01 O2、Li 1.10 Mn 0.52 Ni 0.33 Co 0.04 Ta 0.01 O2、Li 1.10 Mn 0.52 Ni 0.33 Co 0.04 V 0.01 O2、Li 1.10 Mn 0.52 Ni 0.33 Co 0.03 W 0.02 O2、Li 1.10 Mn 0.52 Ni 0.33 Co 0.03 Ta 0.02 O2 and Li 1.10 Mn 0.52 Ni 0.33 Co 0.03 V 0.02 O2.

6. The positive electrode active material according to claim 1, wherein the Ni has an average oxidation state of about 2.

7. A positive electrode active material, which comprises a compound represented by Formula 2: Li 1.12 Mr 0.51 Ni (0.37-x) Co (x-a) M a O2 (2) Wherein: M is for W +6 、 +5 、V +5 or a combination thereof; 0<x<0.1； 0 < a < 0.04; and 3.8 < average oxidation state of Mn ions < 4.

0.

8. The positive electrode active material according to claim 7, wherein 0.001 < x < 0.

099.

9. The positive electrode active material according to claim 7, wherein 0.01 < a < 0.

03.

10. The positive electrode active material according to claim 7, wherein 3.92 < average oxidation state of Mn ions < 3.

98.

11. The positive electrode active material according to claim 7, comprising a material selected from the group consisting of: Li 1.12 Mn 0.5 1Ni 0.29 Co 0.065 W 0.015 O2、Li 1.12 Mn 0.51 Ni 0.29 Co 0.065 Ta 0.015 O2、Li 1.12 Mn 0.51 Ni 0.29 Co 0.065 V 0.015 O2、Li 1.12 Mn 0.51 Ni 0.29 Co 0.05 W 0.03 O2、Li 1.12 Mn 0.51 Ni 0.29 Co 0.05 Ta 0.03 O2 and Li 1.12 Mn 0.51 Ni 0.29 Co 0.05 V 0.03 O2.

12. The positive electrode active material according to claim 7, wherein the Ni has an average oxidation state of about 2.

13. A rechargeable lithium-ion battery, which comprises at least one lithium-ion battery cell, and each lithium-ion battery cell comprises: A positive electrode, the positive electrode comprising a compound represented by Formula 1 or Formula 2: Li 1.10 Mr 0.52 Ni (0.38-x) Co (x-a )M a O2 (1) Li 1.12 Mr 0.51 Ni (0.37-x) Co (x-a) M a O2 (2) Wherein: M is for W +6 、 +5 、V +5 or a combination thereof, 0<x<0.1， 0 < a < 0.04, and 3.8 < average oxidation state of Mn ions < 4.0; A negative electrode, the negative electrode comprising a negative electrode active material; and An electrolyte, the electrolyte contacting the positive electrode and the negative electrode.

14. The rechargeable lithium-ion battery according to claim 13, wherein 0.001 < x < 0.

06.

15. The rechargeable lithium-ion battery according to claim 13, wherein 0.01 < a < 0.02.

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