Method for producing lithiated transition metal oxides

Abstract

Methods for forming electrochemically active materials, such as lithiated transition metal oxides, are provided that address existing issues of yield and calcination. The method includes forming the material in the presence of a processing additive including potassium prior to calcination that produces the active material having an increased primary particle size.

Description

[0001] This application is a divisional application of application number 201980073276.3, application date November 8, 2019, and invention name “Method for Producing Lithiated Transition Metal Oxides”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application relies on and claims priority from U.S. Provisional Application No. 62 / 757,875, filed on November 9, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0004] The present invention relates to the formation of electrochemically active materials suitable for use in primary or secondary batteries, and more particularly to the formation of lithiated transition metal oxides. Background Art

[0005] The formation of electrochemically active materials for batteries generally involves two main steps. First, a precursor is formed, such as by a coprecipitation reaction, whereby transition metals in the form of hydroxides or carbonates are intermixed to form a precursor powder. This precursor is then mixed with a lithium compound and calcined at high temperature to form the active material.

[0006] There is a great desire to improve the electrochemical properties of the active materials formed in these methods and to reduce the production costs. The performance of electrode materials for lithium ion batteries is improved by reducing the particle size of the electrode materials. This is generally due to three main advantages of small particle size. First, smaller particle size is associated with a larger surface area believed to lead to improved charge transfer kinetics. Second, small particle size improves the diffusion kinetics of lithium ions into the interior of the particles, resulting in greater capacity at higher charge / discharge rates. Finally, smaller particles lead to a larger effective contact surface with the electrolyte, which is associated with a greater probability of incorporating lithium ions from the electrolyte and increasing the power density of the battery cell. Therefore, attempts to reduce the particle size of active materials are an ongoing area of ​​research. Recent developments have enabled nanoscale particle sizes to be achieved.

[0007] Although successful in many respects, previous efforts at improving battery cell performance have not achieved the full theoretical capacity of these active materials.Therefore, there remains a need for improved methods of forming electrochemically active materials for electrochemical cells. Summary of the invention

[0008] The following summary is provided to facilitate an understanding of some of the unique and innovative features of the present disclosure and is not intended to be a complete description. A complete understanding of the various aspects of the present disclosure can be obtained by taking the entire specification, claims, drawings, and abstract as a whole.

[0009] A method for improving the resulting electrochemical capacity of an electrochemically active material, such as a lithiated transition metal oxide, is provided. The method includes forming a lithiated transition metal oxide, comprising intermixing a transition metal precursor, a processing additive, and a lithium compound to form an active material precursor, and heating the active material precursor to a temperature, optionally 700° C. or higher, under an oxidizing atmosphere, the heating continuing for a calcination time sufficient to form a lithiated transition metal oxide having a plurality of primary particles having a particle size. Without being limited to a particular theory, it is believed that by increasing the particle size of the active material precursor when combined with the processing additive (optionally by forming a particle size within a predetermined range), an improved transport of the active material in an oxidizing atmosphere is achieved, improving the overall resulting material. Optionally, a processing additive is added to the system prior to a first calcination. Optionally, the active material precursor is subjected to a first calcination (optionally, prior to exposure to a processing additive), and the resulting particles are then intermixed with the processing additive to form a second lithiated transition metal oxide having a particle size greater than the first particle size achieved according to the first calcination. The second lithiated transition metal precursor may then be subjected to a second calcination. The processing aid optionally includes potassium, and is optionally a potassium salt, optionally a carbonate or hydroxide of potassium. The processing additive may be present in 0.1 wt % to 10 wt %. In some aspects, improved results may be achieved by forming particles having a particle size of 2 μm or greater, optionally 2 μm to 15 μm, optionally 4 μm to 15 μm. In some aspects, the molar ratio of lithium to transition metal in the active material precursor is 0.8 to 1.1. In some aspects, the transition metal precursor optionally includes Ni, Co, Mn, Al, Mg, Ti, Zr, Nb, Hf, V, Cr, Sn, Cu, Mo, W, Fe, Si, B, other transition metals, or rare earth elements or any combination thereof. The lithium compound is optionally lithium hydroxide, lithium oxide, lithium carbonate, lithium nitrate, lithium sulfate, lithium acetate, lithium peroxide, lithium bicarbonate, lithium halide or a combination thereof. Optionally, the heating step is under an oxidizing atmosphere, optionally under an oxygen-rich or ozone-rich atmosphere, where "rich" is relative to the oxygen or ozone level in the Earth's atmospheric air at sea level. The heating step is optionally at a temperature of 700° C. to 1000° C. The calcination time is optionally 1-60 hours. The lithiated transition metal oxide formed from the method provided herein optionally has a crushing strength of less than 40 Newtons. The lithiated transition metal oxide is optionally crushed and optionally pre-charged for subsequent use in an electrochemical cell or other desired use. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The aspects set forth in the drawings are illustrative and exemplary in nature and are not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative aspects can be understood when read in conjunction with the following drawings, and wherein:

[0011] Figure 1 illustrates a schematic diagram of a method for forming a lithiated transition metal oxide provided herein according to some aspects;

[0012] Figure 2A The figure shows that in the absence of K 2 CO 3 LiNiO formed and calcined without processing additives 2 Scanning electron microscopy image of particles (5 μm scale bar), illustrating the relatively small primary particle size;

[0013] Figure 2B The diagram shows that in the presence of K 2 CO 3 LiNiO formed and calcined without processing additives 2 Scanning electron microscopy image of particles (5 μm scale bar), illustrating the relatively large primary particle size;

[0014] Figure 3A The figure shows that in the absence of K 2 CO 3 LiNi formed and calcined without processing additives 0.8 Co 0.1 Mn 0.1 O 2 Scanning electron microscope image of the particles (2.5 μm scale bar), illustrating the relatively small primary particle size; and

[0015] Figure 3B The diagram shows that in the presence of K 2 CO 3 LiNi formed and calcined without processing additives 0.8 Co 0.1 Mn 0.1 O 2 Scanning electron microscope image of particles (2.5 μm scale bar), illustrating the relatively large primary particle size. DETAILED DESCRIPTION

[0016] The present disclosure relates to a new method for forming electrochemically active materials that are optionally used in electrochemical cells. Rather than focusing on the composition or structure of such active materials, the present invention is directed to reducing the time required to produce electrochemically active materials by reducing the calcination time and, in some aspects, reducing the hardness of the material after calcination. It has been found that intentionally forming a relatively large primary particle size before calcination increases the yield of the calcination reaction and improves material handling in calcination and downstream processes. Existing methods for producing electrochemically active materials result in a final primary particle size of less than 500 nm. These small primary particle sizes are considered desirable due to electrochemical performance. However, the inventors have found that by increasing the size of the primary particles before the final calcination, improved performance can be achieved with reduced production time / cost. Therefore, the methods of the present invention are in direct contradiction to existing methods because they result in relatively large particle sizes, optionally with a diameter of about 2 μm or more. It is these relatively large particle size materials that undergo the calcination reaction.

[0017] Additionally, the provided methods meet the need for reduced costs due at least to greater throughput and more efficient formation of electrochemically active materials.Estimates of production costs indicate that using large particle sizes as described herein in the production of electrochemically active materials will have significantly reduced costs relative to existing methods.

[0018] As used herein, the term "lithiated transition metal oxide" refers to a metal oxide, optionally a mixed metal oxide, comprising lithium and at least one transition metal, wherein the material has been calcined.

[0019] As used herein, the term "transition metal precursor" refers to a transition metal in the form of a hydroxide, oxide, oxyhydroxide, carbonate or nitrate.

[0020] As used herein, the term "lithium compound" refers to a lithium-containing composition in the form of lithium hydroxide, lithium oxide, lithium carbonate, lithium nitrate, lithium sulfate, lithium acetate, lithium peroxide, lithium bicarbonate, or lithium halide.

[0021] As used herein, the term "active material precursor" refers to the product of an intermixing between a lithium compound, a transition metal precursor, and in some aspects, a processing additive as provided herein.

[0022] The term "calcination" as used herein is understood to mean a heat treatment in the presence of an oxidizing atmosphere so as to cause a chemical transformation of the material.

[0023] Temperatures provided herein are optionally absolute temperatures as stated, or approximate temperatures defined as ±10°C of an absolute number.

[0024] As used herein, "particle size" is an identifiable structure with an increased diameter (average cross-sectional dimension) relative to the material produced in the absence of the processing additives provided herein, typically having a particle size of 0.5 micrometers (μm) or greater. Particle size is measured by a microscope such as a transmission electron microscope, rather than by a standard particle size analyzer.

[0025] A method for forming an electrochemically active material suitable for optionally reversibly embedding Li is provided. Optionally, the electrochemically active material is a transition metal oxide, an iron phosphate, a titanate active material, a LiMnO system that may or may not include other elemental components, or a LiCoO system that may or may not include other elemental components. Illustrative examples of transition metal oxide electrochemically active materials include, but are not limited to, chemical substances based on LiNiMO, where M is optional in the material and can be any transition metal, rare earth, or a combination thereof. Although most of the present disclosure relates to transition metal oxide electrochemically active materials, such as those based on Ni on an atomic basis, it should be understood that the methods of increasing the primary particle size and calcination are equally attributable to other electrochemically active materials.

[0026] It has been found that by intermixing a processing additive including potassium with an active material precursor, a relatively large particle size of primary particles can be achieved during the calcination reaction. Without being limited to a particular theory, it is believed that the larger particle size promotes improved transmission of an oxidizing atmosphere or its components during calcination, thereby allowing a suitable final product to be formed with a reduced calcination time. In addition, some aspects of the methods provided herein provide materials with reduced hardness relative to existing methods, thereby improving subsequent processability for final incorporation into an electrode or other suitable uses. Therefore, in some aspects, the method provided in the present disclosure includes: intermixing a transition metal precursor, a lithium compound, and a processing additive to form an active material precursor; and heating the active material precursor to a temperature of 700° C. or higher under an oxidizing atmosphere, and heating for a calcination time sufficient to form a lithiated transition metal oxide having a primary particle size of 0.5 mm or greater. In some aspects, the transition metal precursor and the lithium compound are first intermixed, a first calcination is performed, and then the particles are intermixed with the processing additive and a second calcination reaction is performed to form a relatively large primary particle size.

[0027] It should be understood that the method includes forming an active material precursor before or simultaneously with the combination with the processing additive. The active material precursor is formed by intermixing the Li compound with the transition metal precursor. Optionally, the active material precursor is formed by intermixing the transition metal precursor with the Li compound in the absence of other materials or in the absence of the processing additive. Optionally, the processing additive is combined with the active material precursor after calcining. Alternatively, the processing additive is intermixed with the transition metal precursor and the Li compound simultaneously, so that the Li compound and the transition metal precursor are optionally not significantly or intentionally mixed before combining with the processing additive.

[0028] The lithium compound used herein is any suitable lithium compound known in the art for forming an electrochemically active material, optionally lithium hydroxide, lithium oxide, lithium carbonate, lithium nitrate, lithium sulfate, lithium acetate, lithium peroxide, lithium bicarbonate, lithium halide or a combination thereof.

[0029] The lithium compound is intermixed with the transition metal precursor. The transition metal precursor can be formed by any method known in the art. In some aspects, the transition metal precursor can be formed by a coprecipitation reaction, wherein hydroxides, carbonates, nitrates or other known suitable transition metal forms are used to form a solution. By adjusting the pH of the solution, the precipitate of the transition metal forms a transition metal precursor.

[0030] The step of intermixing the transition metal precursor and the lithium compound and optionally processing additives can be carried out at various temperatures, optionally 0° C. to 100° C. or even higher, optionally 10° C. to 40° C. The intermixing can be carried out at any suitable pressure, optionally about 1 atmosphere.

[0031] The transition metal can be any transition metal suitable for use in an electrochemical cell. Illustrative examples of transition metals include, but are not limited to, Ni, Co, Mn, Al, Mg, Ti, Zr, Nb, Hf, V, Cr, Sn, Cu, Mo, W, Fe, Si, B or other transition metals. Optionally, the transition metal used herein includes or does not include a rare earth metal. Rare earth metals are particularly optionally La, Nd, Y. In some aspects, the transition metal precursor includes Ni, Mn, Co, Fe or a combination thereof. In some aspects, the transition metal precursor includes Ni.

[0032] In some aspects, the transition metal precursor includes Ni at an atomic percentage (at%) of 10 at% or more relative to other transition metals in the transition metal precursor, optionally 20 at% or more, optionally 30 at% or more, optionally 40 at% or more, optionally 50 at% or more, optionally 60 at% or more, optionally 70 at% or more, optionally 80 at% or more, optionally 90 at% or more, optionally 95 at% or more, optionally 96 at% or more, optionally 97 at% or more, optionally 98 at% or more, optionally 99 at% or more. Optionally, the atomic percentage of Ni is 70 at% to 99 at% or more. Optionally, the atomic percentage of Ni is 80 at% to 99 at% or more. Optionally, the atomic percentage of Ni is 90 at% to 99 at% or more. Optionally, Ni is the only transition metal designed or present in the material so that Ni is present at substantially 100 at%.

[0033] Optionally, the transition metal precursor includes Ni and one or more other transition metals. One or more other transition metals (except Ni) are each separately and optionally present in 0at% to 90at%, optionally 1at% to 90at%. Optionally, one or more other transition metals are each separately and optionally present in 0at% to 50at%, optionally 1at% to 50at%. Optionally, one or more other transition metals are each separately and optionally present in 1at% to 30at%, optionally 1at% to 20at%, optionally 1at% to 10at%, 1at% to 7at%, 1at% to 5at%, 2at% to 20at%, 5at% to 20at%, 10at% to 20at%. Optionally, 1, 2, 3 or more other transition metals except Ni are present in the transition metal precursor.

[0034] According to some aspects, the method provided herein has the advantage that raw precursor materials can be used, eliminating the requirement for highly purified or refined materials. For example, when nickel is used as a transition metal precursor, Ni can be of mine grade. The transition metal precursor can be of mine grade, or can be further processed or refined.

[0035] The transition metal precursor is intermixed with the lithium compound and optionally a processing additive to form an active material precursor. Intermixing is optionally carried out to form a substantially uniform material, thereby achieving excellent mixing of the material and achieving close contact between the Li compound and the transition metal precursor. A high shear mixer can be used, such as a Kawata Super Piccolo mixer or an Eirich mixer. Any suitable stirring blade can be used, such as a pin type blade, a star blade or a micro-granulation type blade. The tip speed of the blade is associated with the amount of shear or friction delivered to the material. The tip speed is optionally 5-30 meters per second (m / s), optionally 10-25m / s.

[0036] The stoichiometric ratio of Li to the transition metal may be any suitable ratio, optionally 0.8 to 1.1 or any value or range therebetween. Optionally, the ratio of Li to the transition metal may be 0.9 to 1.1, optionally 0.95 to 1.1, optionally 0.95 to 1.05. In the case of a Ni-containing active material precursor, the stoichiometric ratio is measured as the ratio between Li and Ni in the material. The stoichiometric ratio of Li to the transition metal may be measured by any method known in the art. Illustratively, standard methods of inductively coupled plasma atomic emission spectroscopy (ICP) or atomic absorption spectroscopy are used, optionally as described by JRDean (Practical Inductively Coupled Plasma Spectroscopy), Chichester, England: Wiley, 2005, 65-87) and Welz and Sperling (Atomic Absorption Spectrometry, 3rd edition, Weinheim, Germany: Wiley VCH, 1999, 221-294). Illustratively, the chemical composition of each sample can be examined by a Varian Liberty 100 inductively coupled plasma (ICP) system.

[0037] In some aspects, the method includes forming a first active material precursor having a plurality of primary particles having a first particle size. Thus, the active material precursor is formed according to conventional techniques and can therefore be defined by typical parameters of such materials, such as particle size, porosity, density, among others. Optionally, the first active material precursor is subjected to a calcination reaction to produce a first lithiated transition metal oxide having a plurality of primary particles having a first particle size. Optionally, the first transition metal oxide is then intermixed with a processing additive and the resulting mixture is subjected to a second calcination reaction to produce a second lithiated transition metal oxide having a plurality of primary particles having a second particle size, wherein the second particle size is greater than the first particle size.

[0038] The particle size can be determined using any known method, but is optionally obtained by microscopy. Optionally, the particle size can be obtained by sieving the material, scanning electron microscopy, transmission electron microscopy, or other suitable methods (such as aspects where the particle size is too large for a standard particle size analyzer or the material is not suitable for analysis in a standard particle analyzer). Optionally, the particle size is obtained using a particle analyzer capable of measuring particle sizes up to 8 millimeters (mm) or more, such as a SympaTec Helos particle size analyzer.

[0039] In the methods provided herein, a lithiated transition metal oxide having a plurality of primary particles having a particle size of 0.5 micrometers (μm) or greater is formed, wherein the particle size is related to the diameter of the sphere using methods recognized in the art. Optionally, the particle size is 0.5 μm to 15 μm or any value or range therebetween. Optionally, the particle size is 2 μm to 15 μm. Optionally, the particle size is 4 μm to 15 μm. Optionally, the particle size is or is greater than 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm or greater. Optionally, the particle size is 0.5 μm to 10 μm, 0.5 μm to 9 μm, 0.5 μm to 8 μm, 0.5 μm to 7 μm, 0.5 μm to 6 μm, 0.5 μm to 5 μm, 0.5 μm to 4 μm, 1 μm to 15 μm, 1 μm to 10 μm, 1 μm to 9 μm, 1 μm to 8 μm, 1 μm to 7 μm, 1 μm to 6 μm, 1 μm to 5 μm. m, 2μm to 15μm, 2μm to 10μm, 2μm to 9μm, 2μm to 8μm, 2μm to 7μm, 2μm to 6μm, 2μm to 4μm, 2μm to 4μm or 2μm to 3μm, 4μm to 15μm, 4μm to 10μm, 4μm to 9μm, 4μm to 8μm, 4μm to 7μm, 4μm to 6μm or 4μm to 5μm.

[0040] The lithium transition metal oxide optionally includes a plurality of primary particles having a particle size of 2 μm or greater, optionally 4 μm or greater, and can be formed by combining an active material precursor or one or more transition metal precursors, a lithium compound, and one or more processing additives. The processing additive is a compound including potassium, optionally a potassium salt. In a specific aspect, the processing additive is a carbonate or hydroxide of potassium, illustratively K 2 CO 3 Or KOH. Optionally, the processing additive does not include KOH.

[0041] The processing additive is combined with other desired materials in the method as provided herein in a weight percentage of 0.1% to 10% or any value or range therebetween, wherein the weight percentage is relative to the sum of the other materials in the active material precursor. Optionally, the processing aid is present in a weight percentage of 0.1% to 20%, optionally 0.1% to 10%, optionally 0.1% to 8%, optionally 0.1% to 7%, optionally 0.1% to 5%, optionally 0.1% to 1%, optionally 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20% or more.

[0042] The processing aid may be combined with the active material precursor by simple addition, spraying or other suitable methods.

[0043] The active material precursor, optionally its components, and one or more processing additives are intermixed to provide a coated or substantially uniformly intermixed mixture. The formation of the active material precursor and the processing aid can be carried out in the same or different container as the step of intermixing the lithium compound and the transition metal precursor, or it can occur in the same container.

[0044] The resulting lithiated transition metal oxides provided herein optionally have a crush strength lower than that of a compositionally identical material formed by conventional methods without a processing aid provided herein. The crush strength can be measured by standard procedures recognized in the art. Optionally, the crush strength is less than 40 Newtons. Optionally, the crush strength is 40 Newtons or less, optionally 35 Newtons or less, optionally 30 Newtons or less, optionally 25 Newtons or less, optionally 20 Newtons or less, optionally 15 Newtons or less, optionally 10 Newtons or less, optionally 9 Newtons or less, optionally 8 Newtons or less, optionally 7 Newtons or less, optionally 6 Newtons or less, optionally 5 Newtons or less, optionally 4 Newtons or less, optionally 3 Newtons or less, optionally . Newtons or less. Optionally, the crush strength is 60% or less, optionally 50% or less, optionally 40% or less, optionally 30% or less of the crush strength of a compositionally identical material formed by conventional methods without the processing aids provided herein.

[0045] After forming the active material precursor either alone or in the presence of a processing additive as provided herein, the resulting material is subjected to a solid phase reaction, such as calcination. A saggar can be used for the calcination process of the present disclosure, but the calcination process is improved due to the reduced processing time for achieving the desired particle size of the resulting lithiated transition metal oxide. In addition to standard kilns and saggars, the material of the present invention can be calcined in a fluidized bed calciner, a rotary kiln, a roller-bottom kiln, or other such devices.

[0046] The calcination process is carried out at a calcination temperature and an oxidizing atmosphere and for a calcination time suitable for forming a lithiated transition metal oxide. The calcination temperature is optionally any temperature equal to or higher than 700 degrees Celsius (°C). The calcination temperature is optionally 700°C to 1000°C or any value or range therebetween. Optionally, the calcination temperature is 750°C to 950°C, optionally 750°C to 900°C.

[0047] The calcination time is optionally 0.2 to 60 hours or any value or range therebetween. Optionally, the calcination time is 0.2 to 50 hours, optionally 1 to 50 hours, optionally 1 to 60 hours, optionally 10 to 50 hours, optionally 10 to 20 hours. Optionally, the calcination time is less than 60 hours, optionally less than 50 hours, optionally less than 40 hours, optionally less than 30 hours, optionally less than 25 hours, optionally less than 20 hours, optionally less than 15 hours, optionally less than 10 hours.

[0048] Calcination is carried out in an atmosphere suitable for oxidizing the active material precursor. The atmosphere may include an oxidant in a suitable amount or concentration, optionally oxygen, ozone or other suitable agent, the oxidizing atmosphere is optionally in the form of an oxygen-enriched atmosphere, wherein the concentration of oxygen is greater than the concentration of oxygen in the surrounding earth air at sea level. Optionally, the atmosphere is air. Optionally, the atmosphere is provided at a suitable pressure, optionally at about 1 atmosphere. The atmosphere is optionally contacted with the active material precursor at a flow rate that provides a desired number of atmosphere exchanges in the oven. The number of atmosphere exchanges per hour is optionally 3 to 150, optionally 3 to 100, optionally 5 to 150, optionally 5 to 100.

[0049] The resulting lithium transition metal oxide is optionally subjected to one or more post-calcination processes. In some aspects, the lithium transition metal oxide is subjected to crushing, grinding or other processes to reduce the size of the aggregates or pulverize the aggregates to improve downstream processing to ensure homogeneity of the mixture and improve intermixing with binders, conductive compounds or other materials suitable for forming electrodes.

[0050] The lithium transition metal oxides may be used in primary or secondary electrochemical cells. When used in primary electrochemical cells, the lithium transition metal oxides may be subjected to a pre-charging step prior to incorporation into the primary cell, as is recognized in the art.

[0051] Various aspects of the present invention are described by the following non-limiting examples. These examples are for illustrative purposes only and do not limit any practice of the present invention. It should be understood that various changes and modifications may be made without departing from the spirit and scope of the present invention.

[0052] Example

[0053] Embodiment 1:

[0054] Refined nickel hydroxide was used to form the active material precursor. 6.7 g of nickel hydroxide (as described in U.S. Pat. Nos. 6,432,580 and 6,444,363), 3.35 g of lithium hydroxide (LiOH*H 2 O) and 0.1 g of K 2 CO 3 (2 wt% (relative to nickel hydroxide)). The materials were dry mixed to homogeneity using a SPEX CETRIPREP 8000 mixer / grinder for 20 minutes. 2 CO 3 In the case of forming a compositionally identical material.

[0055] The obtained active material precursor was heated at 885°C in a flowing O at a flow rate of 21 SCFH (about 100 exchange rate). 2Calcination was performed in 4% MgCl 2 O. Calcination was performed for 15 hours. Some of the resulting calcined granules were manually crushed using a mortar and pestle and optionally pre-charged by standard techniques for downstream electrochemical analysis.

[0056] The presence or absence of K was investigated by SEM using a JEOL-JSM6320F scanning electron microscope (SEM, JEOL, Tokyo, Japan) with energy dispersive spectroscopy (EDS). 2 CO 3 The particle topology of the material formed in the case of Figure 2A and 2B As shown in the figure. The primary particles in the lithiated transition metal oxides exhibit relatively small primary particle sizes, with the average size after washing being generally less than 3.6 μm. In contrast, when K 2 CO 3 When the active material precursor is formed under the condition of , the obtained primary particles generally have an average particle size of 7.88 μm or more.

[0057] The lithiated transition metal oxide materials were crushed and precharged according to standard procedures for subsequent electrochemical analysis. Electrochemical studies were conducted in a half-cell configuration with a Hg / HgO reference electrode and a 30% KOH solution as the background. The cathode powder was formed by mixing the lithiated transition metal oxide materials with Teflonized acetylene black (TAB-2) at 50% w / w and compacting them on a nickel mesh for testing. The battery was continuously discharged at a constant rate of 9mA / g down to -0.8V (compared to the Hg / HgO reference electrode). Table 1 shows the resulting capacity, particle size and crush strength of the material.

[0058] Table 1:

[0059]

[0060] Embodiment 2:

[0061] By adding 1.4 g of LiOH and 0.1 g of K 2 CO 3 5 g of precursor Ni (2 wt% (relative to mixed metal hydroxide)) was added 0.8 Co 0.1 Mn 0.1 (OH) 2 To prepare the lithium cathode material LiNi 0.8 Co 0.1 Mn 0.1 O 2 The control material was formed in the same manner, but in the absence of K 2 CO3 The materials were mechanically mixed using a SPEX CETRIPREP 8000 mixer / grinder for 20 minutes. The resulting powdered mixture was then sintered at 850°C for 15 hours. The resulting lithiated composite material was then cooled to 25°C.

[0062] The morphology of the ions in the absence or presence of K was investigated by SEM using a JEOL-JSM6320F scanning electron microscope (SEM, JEOL, Tokyo, Japan) with energy dispersive spectroscopy (EDS). 2 CO 3 The particle topology of NCM 811 material formed under the condition of Figure 3A and 3B The relative particle sizes are shown in Table 2.

[0063] Table 2: In the presence or absence of K 2 CO 3 The average particle size of the NCM material manufactured under the condition.

[0064]

[0065] For electrochemical analysis, the calcined material was ground in a mortar / pestle and pre-charged by standard techniques. The capacity level and cycle life of the de-lithiated cathode material in a CR2032 coin cell using lithium metal as the counter electrode were studied. The lithiated composite material was formed into a cathode powder for testing by mixing with Super 65 carbon (7.5wt%) from Timcal, graphite KS10 (7.5wt%) from Timcal, and 6wt% of PVDF (Kynar) binder. An anhydrous solvent (1-methyl-2-pyrrolidone) was then added to the powder mixture to form a slurry. The slurry was then coated on an aluminum substrate. The coating was dried at 85°C for several hours and rolled to a final thickness of about 60μm. The cathode and anode materials were separated by a microporous polypropylene separator (MTI) wetted with an electrolyte consisting of 1 M LiPF dissolved in a 1:1:1 volume mixture of ethylene carbonate (EC), dimethyl carbonate (DMC), and diethyl carbonate (DEC) from Novolyte. 6 Solution composition. The battery cells were crimped and used to probe the capacity and cycle life of the lithiated composites. The battery cell assembly and crimping were performed in a glove box.

[0066] Tests on the cathode materials were run at constant current charge and discharge (0.1C) using a Solatron 1470 battery test unit and an Arbin Instrument battery tester power system to determine capacity and cycling capability. The coin cells were charged and discharged at voltages between 4.3 V and 3.0 V. Cycling performance testing was performed at charge and discharge currents of 18 mA / g each.

[0067] The foregoing description of one or more specific aspects is merely exemplary in nature and is in no way intended to limit the scope of the invention, its application or use, which, of course, may vary. The disclosure is provided in connection with the non-limiting definitions and terms included herein. These definitions and terms are not intended to serve as limitations on the scope or practice of the invention, but are presented for illustrative and descriptive purposes only. Although the method or composition is described as a sequence of individual steps or using specific materials, it should be understood that it is readily understood by those skilled in the art that the steps or materials may be interchangeable, so that the description of the present invention may include multiple parts or steps arranged in many ways.

[0068] It will be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one (individual) element, component, region, layer or part from another (individual) element, component, region, layer or part. Therefore, without departing from the teachings of this article, the "first element", "component", "region", "layer" or "part" discussed below may be referred to as a second (or other) element, component, region, layer or part.

[0069] The terms used herein are only for the purpose of describing specific embodiments and are not intended to be restrictive. Unless otherwise clearly stated in the content, the singular forms "one or a kind (a)", "one or a kind (an)" and "the or described (the)" used herein are intended to include plural forms, including "at least one (kind)". "Or" means "and / or". The term "and / or" used herein includes any and all combinations of one or more of the associated listed items. It will be further understood that when used in this specification, the terms "comprise" and / or "comprising" or "include" and / or "including" specify the presence of specified features, regions, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components and / or their groups. The term "or a combination thereof" means a combination including at least one of the aforementioned elements.

[0070] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. It will also be further understood that, unless expressly defined herein, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal manner.

[0071] Various modifications of the invention in addition to those shown and described herein will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.

[0072] The patents, publications and applications mentioned in the specification are indicative of the levels of those skilled in the art to which the invention pertains. These patents, publications and applications are incorporated herein by reference to the same extent as if each individual patent, publication or application was specifically and individually incorporated herein by reference.

[0073] The foregoing description is illustrative of certain aspects of the invention and is not intended to limit the practice thereof.

Claims

1. A method for forming lithiated transition metal oxide particles, include: intermixing one or more transition metal precursors, a lithium compound, and a processing additive including potassium to form an active material precursor; as well as The active material precursor is heated to a temperature of 700° C. or higher in an oxidizing atmosphere for a calcination time sufficient to form a lithiated transition metal oxide having a plurality of primary particles having a particle size.

2. The method according to claim 1, in, The processing additive includes potassium carbonate or hydroxide, or a combination thereof.

3. The method according to claim 1, in, The primary particles have a particle diameter of 2 μm or more.

4. The method according to claim 1, in, The primary particles have a particle size of 4 μm to 15 μm.

5. The method of any one or more of claims 1-4, further comprising mixing the lithiated transition metal oxide with a binder.

6. The method according to any one or more of claims 1 to 4, in, The molar ratio of lithium to transition metal in the active material precursor is 0.8 to 1.

1.

7. The method according to any one or more of claims 1 to 4, in, The processing additive is present at 0.1 wt % to 10 wt %.

8. The method according to any one or more of claims 1 to 4, in, The transition metal precursor includes Ni, Co, Mn, Al, Mg, Ti, Zr, Nb, Hf, V, Cr, Sn, Cu, Mo, W, Fe, Si, Zn, B, other transition metals, rare earth elements or combinations thereof.

9. The method according to any one or more of claims 1 to 4, in, The lithium compound is selected from the group consisting of lithium hydroxide, lithium oxide, lithium carbonate, lithium nitrate, lithium sulfate, lithium acetate, lithium peroxide, lithium bicarbonate, lithium halide, and combinations thereof.

10. The method of any one or more of claims 1-4, further comprising crushing the lithiated transition metal oxide particles.

11. The method according to any one or more of claims 1 to 4, in, The heating step is carried out in a fluidized bed calciner, a rotary kiln or a roller hearth kiln.

12. The method according to any one or more of claims 1 to 4, in, The oxidizing atmosphere is an oxygen-rich atmosphere.

13. The method according to any one or more of claims 1 to 4, in, The lithiated transition metal oxide has a crush strength of less than 40 Newtons.

14. The method according to any one or more of claims 1 to 4, in, The temperature is 700°C to 1000°C.

15. The method according to any one or more of claims 1 to 4, in, The time is 0.2 to 60 hours.

16. A method for forming a lithiated transition metal oxide, include: mixing a nickel-containing material and a lithium compound to form an active material precursor; heating the active material precursor to a temperature of 700° C. or higher in an oxidizing atmosphere for a calcination time sufficient to form first lithiated transition metal oxide particles having a plurality of primary particles having a first particle size; intermixing the first lithiated transition metal oxide particles with a processing additive comprising potassium to form second lithiated transition metal oxide particles; and The second active material precursor is heated to a temperature of 700° C. or higher in an oxidizing atmosphere to form particles, wherein the plurality of primary particles have a second particle size, wherein the second particle size is larger than the first particle size.

17. The method according to claim 16, in, The second lithiated transition metal oxide has a plurality of primary particles having a second particle size of 2 μm or more.

18. The method according to any one of claims 16, in, The second particle size is 6 μm to 15 μm.

19. The method according to any one of claims 16 to 18, in, The nickel-containing material includes nickel monoxide, nickel hydroxide, nickel oxyhydroxide, nickel trioxide, nickel carbonate, nickel nitrate or any combination thereof.

20. The method according to any one of claims 16 to 18, in, The nickel-containing material further includes Al, Co, Mn or any combination thereof.

21. The method according to any one of claims 16 to 18, in, The lithium compound is selected from the group consisting of lithium hydroxide, lithium oxide, lithium carbonate, lithium nitrate, lithium sulfate, lithium acetate, lithium peroxide, lithium bicarbonate, lithium halide, and combinations thereof.

22. The method according to any one of claims 16 to 18, in, The processing additive is present in an amount of 0.5% to 5% by weight of the active material precursor as a whole.

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