Cathode Materials and Processes

Abstract

The present invention relates to a process for preparing a particulate lithium manganese nickel spinel compound, and the materials produced thereby, in the field of battery materials. The process of the present invention uses a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and optionally an M-containing precursor, which precursors do not substantially form NOx gases during calcination. The particulate lithium manganese nickel spinel compound product of the process can be utilized in lithium-ion batteries.

Description

[Technical Field]

[0001] The present invention relates to processes for preparing lithium manganese nickel oxide spinel materials, the lithium manganese nickel oxide spinel materials resulting from those processes, and electrodes and cells containing these materials. [Background technology]

[0002] Lithium manganese oxides have been identified as useful cathode materials in lithium-ion batteries. Among the lithium manganese oxides, LiMn2O4 (stoichiometric spinel), Li2Mn4O9 (oxygen-enriched spinel), and Li4Mn5O 12 Compounds with spinel structures, such as (lithium-enriched spinels), have shown particular promise as cathode materials.

[0003] Such spinel compounds are made by combining metal salt precursor compounds, usually metal nitrates such as manganese nitrate. Nitrate precursors are not only expensive but also emit toxic NO x This requires treatment of the process exhaust gas to remove gases. However, no alternative approach to preparing suitably high-volume spinels has been proposed in the art.

[0004] Therefore, at high potentials vs. Li / Li + There is a need for an improved process for preparing spinel compounds for use in lithium battery applications, such as lithium ion battery applications, that can intercalate lithium at a rate that provides high capacity and provides a product with good cyclability (capacity retention). Summary of the Invention

[0005] The present inventors have discovered that a specific process for preparing lithium manganese nickel oxide (LMNO) spinel compounds not only provides compounds with high capacity and improved cyclability, but also reduces the toxicity of toxic NOx It has been found to eliminate the production of exhaust gases, thereby eliminating the need for costly, difficult and potentially dangerous exhaust gas treatment.

[0006] Accordingly, a first aspect of the present invention is a process for preparing a particulate lithium manganese nickel spinel compound, the process comprising: (a) preparing a composition comprising a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and optionally an M-containing precursor, wherein a single compound may optionally contain two or more of Mn, Ni, and M; (b) grinding the composition; and (c) calcining the product of step (b); M is one or more elements selected from Al, Mg, Ti, Co, Cu, and Cr; The Mn-containing precursor, Ni-containing precursor, Li-containing precursor, and optional M-containing precursor may be converted to NO during calcination in step (c). x It is selected so that substantially no gas is formed.

[0007] Some embodiments provide a process for preparing a particulate lithium manganese nickel spinel compound of formula I: Li x Mn y Ni z M a O b Formula I This process is (a) preparing a composition comprising a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and optionally an M-containing precursor, wherein a single compound may optionally contain two or more of Mn, Ni, and M; (b) grinding the composition; and (c) calcining the product of step (b); wherein M is one or more elements selected from Al, Mg, Ti, Co, Cu, and Cr; 0.8≦x≦1.2, y=2-za, 0.2 <z<1.2であり、 0≦a≦0.06, 3.5≦b≦4.5, The Mn-containing precursor, Ni-containing precursor, Li-containing precursor, and optional M-containing precursor may be converted to NO during calcination in step (c). x It is selected so that substantially no gas is formed.

[0008] The manufacturing method of the present invention produces NO when fired. x Select starting materials that do not generate gas, thereby reducing the x This eliminates the need for costly, difficult, and potentially dangerous exhaust gas treatment to remove gases (i.e., NO, NO2, or mixtures thereof). Furthermore, the product spinel has very good properties. High capacities of at least 120 mAh / g can be achieved, and in some cases, as high as 134 mAh / g can be achieved. The product has a 6 mg / cm 2 The battery can retain at least 93% of its initial capacity after 200 cycles at a C / 2 discharge rate at 23° C. with an electrode load of 1000 kJ / cm2, and in some cases can retain as much as 96% of its initial capacity.

[0009] A second aspect of the invention is a lithium manganese nickel spinel compound obtained or obtainable by a process according to the first aspect.

[0010] A third aspect of the present invention provides a positive electrode active material comprising a compound according to the second aspect.

[0011] A fourth aspect of the present invention provides an electrode comprising a material according to the third aspect.

[0012] A fifth aspect of the invention provides a lithium secondary cell or battery comprising an electrode according to the fourth aspect.

[0013] A sixth aspect of the invention is the use of a compound according to the second aspect in a lithium secondary cell or battery.

[0014] A seventh aspect of the present invention relates to the production of particulate lithium manganese nickel spinel compounds from a calcination process. x A method for reducing or eliminating the emission of gas products, the method comprising: x selecting the Mn-containing precursor, the Ni-containing precursor, the Li-containing precursor, and optionally the M-containing precursor such that substantially no gas is formed, where M is one or more elements selected from Al, Mg, Co, Cu, Cr, and Ti.

[0015] An eighth aspect of the present invention is a method for improving the initial capacity and / or cyclability of a particulate lithium manganese nickel spinel compound, the method comprising: removing, during the preparation of the lithium manganese spinel compound, a D 90 The method includes using a Mn-containing precursor having a particle size. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a plot of the specific capacity of three comparative materials (Samples C, D, and E) at various discharge rates ("C-rates"). [Figure 2] 1 shows the specific capacity of three comparative materials (Samples C, D and E) plotted against the number of discharge cycles. [Figure 3] 1 is a plot of the discharge potential curves of three comparative materials (Samples C, D, and E). [Figure 4] 1 is a plot of the discharge potential curves for a material made according to a process of the present invention (Sample A) and a comparative material (Sample C). [Figure 5] 1 is a plot of the specific capacity of a material made according to a process of the present invention (Sample A) and a comparative material (Sample C) at various discharge rates ("C-rates"). [Figure 6] 1 shows the specific capacity of a material made according to a process of the present invention (Sample A) and a comparative material (Sample C) plotted against the number of discharge cycles. [Figure 7]1 is a plot of discharge potential curves for two different materials (Samples A and B) made according to the process of the present invention. [Figure 8] 1 shows (a) the particle size distribution of the first MnCO3 powder used as a precursor, and (b) the particle size distribution of the second MnCO3 powder used as a precursor. [Figure 9] 1 shows (a) the particle size distribution of a lithium manganese nickel spinel material (Sample A) prepared by the process of the present invention, and (b) an SEM image of a lithium manganese nickel spinel material (Sample A) prepared by the process of the present invention. [Figure 10] 1 shows an XRD scan of a lithium manganese nickel spinel material (Sample A) prepared by the process of the present invention. [Figure 11] 1 shows the discharge curves of a lithium manganese nickel spinel material (Sample F) at various discharge rates. [Figure 12] 1 shows the particle size distribution of MnCO3 powder used as a precursor in Comparative Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0017] Preferred and / or optional features of the invention will now be described. Any aspect of the invention may be combined with any other aspect of the invention unless the context requires otherwise. Any preferred and / or optional feature of any aspect may be combined with any aspect of the invention, either singly or in any combination, unless the context requires otherwise.

[0018] The exact composition of the final lithium manganese nickel spinel product in the process of the present invention is not particularly limited. The present invention relates to an improved process applicable to the preparation of a range of lithium manganese nickel spinel materials, and one skilled in the art can adjust the types and amounts of starting materials accordingly depending on the desired end product.

[0019] In some embodiments, the particulate lithium manganese nickel spinel compound has a composition according to Formula I, Li x Mn y Ni z M a O b Formula I where M is one or more elements selected from Al, Mg, Ti, Co, Cu, and Cr, 0.8 ≦ x ≦ 1.2, y = 2 - z - a, 0.2 < z < 1.2, 0 ≦ a ≦ 0.06, 3.5 ≦ b ≦ 4.5.

[0020] In Formula I, 0.8 ≦ x ≦ 1.2. In some embodiments, x is 0.9 or more, or 0.95. In some embodiments, x is 1.1 or less, or 1.05 or less. In some embodiments, 0.90 ≦ x ≦ 1.10, for example, 0.95 ≦ x ≦ 1.05. In some embodiments, x is about 1.0, for example, equal to 1.0.

[0021] In Formula I, 0.2 < z < 1.2. In some embodiments, 0.2 < z < 1.15, for example, 0.2 < z < 1.1, 0.2 < z < 1.05, 0.2 < z < 1.0, 0.2 < z < 0.95, 0.2 < z < 0.9, ....... 0.3 < z < 0.6. In some embodiments, 0.3 < z < 0.5. In some embodiments, z is about 0.4, for example, equal to 0.4.

[0022] 注:原文中“0.2<z<0.8、0.25<z<0.8、0.3<z<0.8、0.3<z<0.75、0.3<z<0.7、0.3<z<0.65、又は0.3<z<0.6である。”部分的省略号为原文重复内容,我按照原文格式保留了省略号。实际翻译时,你可根据完整内容准确翻译。In Formula I, 0 ≦ a ≦ 0.06. In some embodiments, 0 ≦ a ≦ 0.06, for example, 0 ≦ a ≦ 0.059, 0 ≦ a ≦ 0.058, 0 ≦ a ≦ 0.057, 0 ≦ a ≦ 0.056, 0 ≦ a ≦ 0.055, 0 ≦ a ≦ 0.054, 0 ≦ a ≦ 0.053, 0 ≦ a ≦ 0.052, 0 ≦ a ≦ 0.051, 0 ≦ a ≦ 0.05, 0.01 ≦ a ≦ 0.06, 0.02 ≦ a ≦ 0.06, 0.03 ≦ a ≦ 0.06, 0.03 ≦ a ≦ 0.055, 0.03 ≦ a ≦ 0.05, 0.035 ≦ a ≦ 0.06, or 0.04 ≦ a ≦ 0.06. In some embodiments, a = 0. In some embodiments, a is about 0.05, for example, equal to 0.05.

[0023] In Formula I, 3.5 ≦ b ≦ 4.5. In some embodiments, 3.55 ≦ b ≦ 4.45, for example 3.6 ≦ b ≦ 4.4, 3.65 ≦ b ≦ 4.35, 3.7 ≦ b ≦ 4.3, 3.75 ≦ b ≦ 4.25, 3.8 ≦ b ≦ 4.2, 3.85 ≦ b ≦ 4.15, 3.9 ≦ b ≦ 4.1, or 3.95 ≦ b ≦ 4.05. In some embodiments, b is about 4, for example, equal to 4.

[0024] In Formula I, M is one or more elements selected from Al, Mg, Co, Cu, and Cr. In some embodiments, M is Al. In some embodiments, M is Al and 0 < a ≦ 0.06, for example, 0 < a ≦ 0.059, 0 < a ≦ 0.058, 0 < a ≦ 0.057, 0 < a ≦ 0.056, 0 < a ≦ 0.055, 0.01 < a ≦ 0.06, 0.02 < a ≦ 0.06, 0.03 < a ≦ 0.06, or a is about 0.05, for example, equal to 0.05.

[0025] In formula I, y is (2 - z - a). In some embodiments, 0.74 < y < 1.8, for example, 0.75 < y < 1.8, 0.8 < y < 1.8, 0.85 < y < 1.8, 0.9 < y < 1.8, 0.95 < y < 1.8, 1.0 < y < 1.8, 1.05 < y < 1.8, 1.1 < y < 1.8, 1.15 < y < 1.8, 1.2 < y < 1.8, 1.25 < y < 1.8, 1.3 < y < 1.8, 1.3 < y < 1.75, 1.3 < y < 1.7, 1.4 < y < 1.7, or 1.5 < y < 1.7. In some embodiments, y is about 1.55, for example, equal to 1.55.

[0026] In some embodiments, 0.8 ≤ x ≤ 1.2, 0.2 < z < 1.2, 0 ≤ a ≤ 0.06, 3.5 ≤ b ≤ 4.5, where M is Al.

[0027] In some embodiments, 0.8 ≤ x ≤ 1.2, 0.2 < z < 0.6, 0 ≤ a ≤ 0.06, 3.5 ≤ b ≤ 4.5.

[0028] In some embodiments, 0.9 ≤ x ≤ 1.1, 0.2 < z < 0.6, 0 ≤ a ≤ 0.06, 3.5 ≤ b ≤ 4.5. <00003​​​​​​​​​​​​​​​​​​​ 0≦a≦0.06, 3.9≦b≦4.1.

[0031] In some embodiments, 0.9≦x≦1.1, 0.3 <z<0.5であり、 a=0, 3.9≦b≦4.1.

[0032] In some embodiments, 0.9≦x≦1.1, 0.3 <z<0.5であり、 0.04≦a≦0.06, 3.9≦b≦4.1, In the formula, M is Al.

[0033] In some embodiments, the lithium manganese nickel spinel compound of formula I is LiMn 1.6 Ni 0.4 O4 type IA LiMn 1.55 Ni 0.4 Al 0.05 O b Formula IB LiMn 1.55 Ni 0.4 Ti 0.05 O b formula IC LiMn 1.55 Ni 0.4 Co 0.05 O b Expression ID LiMn 1.50 Ni 0.45 Al 0.05 O b Expression IE LiMn 1.45 Ni 0.5 Al 0.05 O b Expression IF

[0034] where 3.5≦b≦4.5. In some embodiments, the lithium manganese nickel spinel compound of formula I is selected from one of formulas IA through IF, where b=4. In some embodiments, the lithium manganese nickel spinel compound is a compound according to formula IB, where b=4.

[0035] In some embodiments, the particulate lithium manganese nickel spinel compound is a crystalline (or substantially crystalline) material. In some embodiments, the compound crystallizes in the space group Fd-3m. In some embodiments, the lattice parameter is 8.170-8.180 Å, e.g., 8.170-8.175 Å, e.g., 8.170-8.174 Å, e.g., 8.171-8.174 Å.

[0036] The lithium manganese nickel spinel particles typically have a D of at least 4.0 μm, e.g., at least 4.1 μm, at least 4.2 μm, at least 4.3 μm, at least 4.4 μm, at least 4.5 μm, at least 4.6 μm, or at least 4.7 μm. 50 In some embodiments, the lithium manganese nickel spinel particles have a D of at least 7.0 μm, e.g., at least 7.1 μm, at least 7.2 μm, at least 7.3 μm, or at least 7.4 μm. 50 The particles of the lithium manganese nickel spinel typically have a particle size D of 10.0 μm or less, e.g., 10.0 μm or less, 9.5 μm or less, 9.0 μm or less, 8.5 μm or less, 8.0 μm or less, 7.9 μm or less, 7.8 μm or less, 7.7 μm or less, 7.6 μm or less, or 7.5 μm or less. 50 In some embodiments, the particle size is D 50 The particle size is about 4.0 μm to about 10.0 μm, for example, about 5.0 μm to about 9.0 μm. Unless otherwise specified in this specification, D 50 The particle size is Dv 50(volume median diameter) and can be determined by dynamic light scattering (e.g., using a Malvern Mastersizer 2000), e.g., according to ASTM B822 of 2017 under Mie scattering theory.

[0037] The lithium manganese nickel spinel particles typically have a D of at least 1.5 μm, e.g., at least 1.6 μm, at least 1.7 μm, at least 1.8 μm, at least 1.9 μm, at least 2.0 μm, at least 2.2 μm, or at least 2.5 μm. 10 The particles of the lithium manganese nickel spinel typically have a particle size D of 4.0 μm or less, e.g., 3.9 μm or less, 3.8 μm or less, 3.7 μm or less, 3.6 μm or less, or 3.5 μm or less. 10 In some embodiments, the particle size is D 10 The particle size is about 1.5 μm to about 4.0 μm, for example, about 1.6 μm to about 3.9 μm, about 1.7 μm to about 3.8 μm, about 1.8 μm to about 3.7 μm, about 1.9 μm to about 3.6 μm, or about 2.5 μm to about 3.6 μm. 10 The particle size is about 1.0 μm to about 2.7 μm, for example, about 1.05 μm to about 3.7 μm, or about 1.1 μm to about 3.7 μm. 10 Particle size refers to Dv10 (the 10% intercept in the cumulative volume distribution) and can be determined by dynamic light scattering (e.g., using a Malvern Mastersizer 2000), for example, according to ASTM B822 of 2017 under the Mie scattering theory.

[0038] The particles of lithium manganese spinel typically have a D of at least 12.0 μm, e.g., at least 12.5 μm, at least 13.0 μm, at least 13.5 μm, at least 14.0 μm, at least 14.5 μm, or at least 15.0 μm. 90 The particles of the lithium manganese nickel spinel typically have a particle size D of 18.0 μm or less, e.g., 17.9 μm or less, 17.8 μm or less, 17.5 μm or less, 17.0 μm or less, or 16.5 μm or less. 90In some embodiments, the particle size is D 90 The particle size is about 12.0 μm to about 18.0 μm, for example, about 12.5 μm to about 18.0 μm, about 13.0 μm to about 18.0 μm, about 13.0 μm to about 17.0 μm, about 13.5 μm to about 17.0 μm, about 14.0 μm to about 18.0 μm, about 15.0 μm to about 17.0 μm, about 15.5 μm to about 17.0 μm, about 16.0 μm to about 16.5 μm, about 14.0 μm to about 16.0 μm, about 14.0 μm to about 15.5 μm, about 14.0 μm to about 15.0 μm, about 14.0 μm to about 14.5 μm, or about 14.5 μm to about 15 μm. 90 Particle size refers to Dv90 (the 90% intercept in the cumulative volume distribution) and can be determined by dynamic light scattering (e.g., using a Malvern Mastersizer 2000), for example, according to ASTM B822 of 2017 under the Mie scattering theory.

[0039] In some embodiments, the particulate lithium manganese nickel spinel crystallites are substantially octahedral in shape as determined from analysis of SEM images.

[0040] In some embodiments, the particulate lithium manganese nickel spinel compound has a bimodal particle size distribution, in which a first peak occurs between about 4.0 and 7.0 μm and a second peak occurs between about 10.0 and 13.0 μm.

[0041] In some embodiments, the lithium manganese nickel spinel has a tap density of about 1.9 g / cm 3 ~ approx. 2.4g / cm 3 is.

[0042] The tap density of a material may suitably be measured according to ASTM B527. In some embodiments, the BET surface area of ​​the lithium manganese nickel spinel is about 0.5 cm 2 / g ~ approx. 2.5cm 2 / g, for example, about 0.6 cm 2 / g ~ approx. 2.0cm 2 / g, approx. 0.6cm 2 / g ~ approx. 1.5cm 2 / g, approx. 0.7cm 2 / g ~ approx. 1.4cm 2 / g, or approximately 1.0 cm 2 / g.

[0043] The BET surface area of ​​a material may suitably be measured by gas adsorption, i.e. the Brunauer, Emmett and Teller (Emmett and Teller, BET) method according to DIN 66131 (multipoint determination), for example on a Gemini 2360 (Micromeritics) instrument.

[0044] In the process according to the present invention, the first step (a) involves preparing a composition comprising a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and optionally an M-containing precursor.

[0045] In some embodiments, step (a) comprises preparing a slurry comprising a solvent, a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and optionally an M-containing precursor. Thus, some embodiments of the present invention provide a process for preparing a particulate lithium manganese nickel spinel compound, the process comprising: (a) preparing a slurry comprising a solvent, a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and optionally an M-containing precursor, wherein a single compound may optionally contain two or more of Mn, Ni, and M; (b) milling the slurry; (c) calcining the product of step (b); wherein M is one or more elements selected from Al, Mg, Ti, Co, Cu, and Cr; The Mn-containing precursor, Ni-containing precursor, Li-containing precursor, and optional M-containing precursor may be converted to NO during calcination in step (c). x It is selected so that substantially no gas is formed.

[0046] Milling a slurry rather than a dry precursor composition can help provide a more homogeneous mixture of the precursor components.

[0047] In some embodiments, the process further comprises drying the slurry after the grinding step (b) and before the calcining step (c). Drying may comprise spray drying.

[0048] In some embodiments, the solvent is water. In some embodiments, the solvent can be an alcohol.

[0049] In some embodiments, the first step (a) comprises preparing a composition comprising a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and an M-containing precursor. In some embodiments, the first step (a) comprises preparing a slurry comprising a solvent, a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and an M-containing precursor.

[0050] In some embodiments, one or more of the Mn-containing precursor, Ni-containing precursor, Li-containing precursor, and (if present) the M-containing precursor are soluble in the solvent, hi some embodiments, one or more of the Mn-containing precursor, Ni-containing precursor, Li-containing precursor, and (if present) the M-containing precursor are insoluble in the solvent.

[0051] As used herein, "soluble" refers to a solubility of at least 5 g / 100 mL, e.g., at least 10 g / 100 mL, at 25° C. As used herein, "insoluble" refers to a solubility of less than 0.10 g / 100 mL, e.g., less than 0.05 g / 100 mL, e.g., less than 0.02 g / 100 mL, at 25° C.

[0052] In some embodiments, one of the Mn-containing precursor, the Ni-containing precursor, the Li-containing precursor, and the M-containing precursor (if present) is soluble in the solvent, hi some embodiments, the Li-containing precursor is soluble in the solvent, and each of the Mn-containing precursor, the Ni-containing precursor, and the M-containing precursor (if present) is insoluble in the solvent.

[0053] In some embodiments, the first step (a) comprises providing a solution of a Li-containing precursor and adding a Mn-containing precursor, a Ni-containing precursor, and optionally an M-containing precursor to the solution to prepare a slurry. In some embodiments, the solution is an aqueous solution. In some embodiments, each of the Mn-containing precursor, the Ni-containing precursor, and (if present) the M-containing precursor is insoluble in the solvent.

[0054] In some embodiments, the first step (a) comprises dissolving a Li-containing precursor in a solvent and adding a Mn-containing precursor, a Ni-containing precursor, and optionally an M-containing precursor to the solution to prepare a slurry. In some embodiments, each of the Mn-containing precursor, the Ni-containing precursor, and the M-containing precursor (if present) is insoluble in the solvent.

[0055] In some embodiments, the first step (a) further comprises stirring or agitating the solution / slurry during and / or after addition of the precursor.

[0056] In some embodiments, the stirring or agitation of the slurry or solution may be carried out for a period of, for example, at least 10 minutes, at least 20 minutes, or at least 30 minutes, which may be less than 5 hours, for example, less than 2 hours.

[0057] In some embodiments, the first step (a) comprises dissolving a Li-containing precursor in a solvent, adding a Ni-containing precursor and (if present) an M-containing precursor to the solution, stirring or agitating the slurry, then adding a Mn-containing precursor and stirring or agitating the slurry again.

[0058] In some embodiments, the composition prepared in step (a) further comprises H3BO3. Without wishing to be bound by theory, H3BO3 is believed to support crystallization during synthesis, and as a result, lower temperatures can be used.

[0059] Mn-containing precursors are highly sensitive to NO during calcination. x The Mn-containing precursor may be any compound of Mn that does not substantially generate products. In some embodiments, the Mn-containing precursor is insoluble in water at 25° C. In some embodiments, the Mn-containing precursor comprises or consists of one or more of MnCO3, MnO, and Mn3O4. In some embodiments, the Mn-containing precursor comprises or consists of MnCO3.

[0060] Ni-containing precursors are highly sensitive to NO during calcination. x The Ni-containing precursor can be any compound of Ni that does not substantially generate products. In some embodiments, the Ni-containing precursor is insoluble in water at 25° C. In some embodiments, the Ni-containing precursor comprises or consists of one or more compounds selected from Ni(OH), NiO, NiO(OH), nickel sulfate, nickel acetate, and hydrated forms thereof. In some embodiments, the Ni-containing precursor comprises or consists of Ni(OH) or a hydrated form thereof.

[0061] The Li-containing precursors were found to produce NO x The Li-containing precursor can be any compound of Li that does not substantially generate products. In some embodiments, the Li-containing precursor is soluble in water at 25° C. In some embodiments, the Li-containing precursor comprises or consists of one or more compounds selected from LiOH, Li2CO3, and hydrated forms thereof. In some embodiments, the Li-containing precursor comprises or consists of LiOH or hydrated forms thereof.

[0062] M-containing precursors produce NO during calcination. xThe M-containing precursor can be any compound of element M that does not substantially generate products. In some embodiments, the M-containing precursor is insoluble in water at 25° C. In some embodiments, the M-containing precursor comprises one or more compounds selected from M hydroxides, M oxides, M sulfates, M carbonates, M acetates, and hydrated forms thereof. In some embodiments, the M-containing precursor comprises an Al-containing precursor. In some embodiments, the Al-containing precursor comprises or consists of one or more of Al(OH)3 and Al2(SO4)3. In some embodiments, the Al-containing precursor comprises or consists of Al(OH)3.

[0063] In some embodiments, two or more of the Mn-containing precursor, the Ni-containing precursor, and (if present) the M-containing precursor may be provided as a single compound, for example, a mixed metal hydroxide such as a mixed nickel manganese hydroxide.

[0064] NO x "NO" refers to one or both of the two gases nitrogen dioxide (NO2) and nitric oxide (NO). x The term "substantially no gassing" means that the firing does not x No or no gas products are produced x Negligible amounts of NO so that no treatment of the exhaust gas to remove x This means that gas products are produced. For example, in some embodiments, NO produced during calcination x The amount of NO in the exhaust gas from the firing x In some embodiments, the NO produced during calcination is in an amount such that the concentration of NO is less than 50 ppm, e.g., less than 45 ppm, less than 40 ppm, less than 35 ppm, less than 30 ppm, less than 25 ppm, less than 20 ppm, less than 15 ppm, less than 10 ppm, less than 5 ppm, or less than 1 ppm. x The amount of NO in the exhaust gas from the firing xis an amount such that the concentration of is less than 0.9 ppm, e.g., less than 0.8 ppm, less than 0.7 ppm, less than 0.6 ppm, less than 0.5 ppm, less than 0.2 ppm, or less than 0.1 ppm, and in some embodiments, is about 0 ppm.

[0065] NO in exhaust gases from chemical processes x Detects and NO x Suitable methods for monitoring the levels of NO and NO2 are known to those skilled in the art and include gas phase FTIR techniques and mass spectrometry. For example, an Antaris (RTM) IGS FTIR Analyzer from Thermo Scientific (RTM) may be used to monitor the levels of NO and NO2 in the exhaust base.

[0066] Those skilled in the art will recognize that NO x Suitable precursor compounds can be selected that do not substantially generate products. For example, precursor compounds used in this process may be selected that do not generate products in the presence of nitrates. x It is substantially free of N-containing anions, which can cause exhaust emissions.

[0067] In particular, the precursor compounds used in this process are characterized by the presence of nitrates, which are not NO x The term "substantially nitrate-free" refers to the absence of nitrates, for example, unavoidable nitrates as impurities or in the presence of significant amounts of NO x The present invention is intended to tolerate trace amounts of nitrates that do not generate CO₂ and therefore do not require exhaust gas treatment. In some embodiments, each precursor contains less than 10 wt.% nitrates relative to the weight of the metal elements in the precursor. For example, in some embodiments, a Mn-containing precursor contains less than 10 wt.% nitrates (NO₃) relative to the amount of Mn in the precursor. For comparison, the compound Mn(NO₃)₂ contains 225.7 wt.% nitrates relative to the amount of Mn in the compound.

[0068] In some embodiments, each precursor contains less than 5 wt. % nitrate, e.g., less than 4 wt. %, less than 3 wt. %, less than 2 wt. %, less than 1 wt. %, less than 0.9 wt. %, less than 0.5 wt. %, or less than 0.1 wt. %, based on the weight of the metal element in the precursor.

[0069] In some embodiments, each precursor contains less than 5 wt. % nitrogen atoms, e.g., less than 4 wt. %, less than 3 wt. %, less than 2 wt. %, less than 1 wt. %, less than 0.9 wt. %, less than 0.5 wt. %, or less than 0.1 wt. % nitrogen atoms, based on the weight of the metal element in the precursor, including nitrogen present in compounds such as nitrates, nitrites, nitrides, and any organic nitrogen-containing species.

[0070] In some embodiments, the D of the Mn-containing precursor 90 The particle size is at least 2.0 μm, e.g., at least 2.1 μm, at least 2.2 μm, at least 2.3 μm, at least 2.4 μm, or at least 2.5 μm. In some embodiments, the D of the Mn-containing precursor 90 The particle size is 120 μm or less, for example 119 μm or less, 118 μm or less, 117 μm or less, 116 μm or less, 115 μm or less, or 114 μm or less.

[0071] In some embodiments, the D of the Mn-containing precursor 90 The particle size is less than 4 μm. 90 The inventors have found that the use of a Mn-containing precursor in an initial slurry having a particle size provides a superior product with improved capacity and improved cyclability. The inventors have surprisingly found that this also provides a product with particularly high phase purity, as evidenced by analysis of the XRD pattern of the material. In some embodiments, the D of the Mn-containing precursor 90 The particle size is less than 3 μm, which provides particularly good results. In some embodiments, the D of the Mn-containing precursor 90The particle size is less than 2.9 μm, e.g., less than 2.8 μm, less than 2.7 μm, less than 2.6 μm, less than 2.5 μm, less than 2.4 μm, less than 2.3 μm, less than 2.2 μm, less than 2.1 μm, or less than 2.2 μm.

[0072] In some embodiments, the D of the Mn-containing precursor 90 The particle size is about 2.0 μm to about 120 μm, e.g., about 2.0 μm to about 115 μm, about 2.0 μm to about 100 μm, about 2.0 μm to about 50 μm, about 2.0 μm to about 20 μm, about 2.0 μm to about 15 μm, or about 2.0 μm to about 10 μm. In some embodiments, the D of the Mn-containing precursor 90 The particle size is about 2.0 μm to about 4.0 μm, for example, about 2.0 μm to about 3.0 μm, 2.1 μm to about 3.0 μm, about 2.2 μm to about 3.0 μm, about 2.3 μm to about 3.0 μm, about 2.3 μm to about 2.9 μm, about 2.3 μm to about 2.8 μm, about 2.3 μm to about 2.7 μm, about 2.4 μm to about 2.6 μm, or about 2.5 μm.

[0073] In some embodiments, the D of the Mn-containing precursor 50 The particle size is less than 2 μm, e.g., less than 1.9 μm, less than 1.8 μm, less than 1.7 μm, less than 1.6 μm, or less than 1.5 μm. In some embodiments, the D of the Mn-containing precursor 50 The particle size is at least 1.0 μm, e.g., at least 1.05 μm, at least 1.1 μm, at least 1.15 μm, or at least 1.2 μm. In some embodiments, the D 50 The particle size is about 1.0 μm to about 80 μm, e.g., about 1.2 μm to about 75 μm, about 1.2 μm to about 70 μm, about 1.2 μm to about 65 μm, about 1.0 μm to about 50 μm, about 1.0 μm to about 20 μm, or about 1.0 μm to about 5 μm. In some embodiments, the D of the Mn-containing precursor 50 The particle size is about 1.0 μm to about 2.0 μm, for example, about 1.0 μm to about 1.5 μm.

[0074] In some embodiments, the D of the Mn-containing precursor 10The particle size is less than 15 μm, e.g., less than 12 μm, less than 10 μm, less than 9 μm, or less than 8 μm. In some embodiments, the D of the Mn-containing precursor 10 The particle size is less than 2 μm, e.g., less than 1.5 μm, less than 1.4 μm, less than 1.3 μm, less than 1.2 μm, less than 1.1 μm, or less than 1 μm. In some embodiments, the D of the Mn-containing precursor 10 The particle size is at least 0.4 μm, e.g., at least 0.45 μm, at least 0.5 μm, at least 0.55 μm, or at least 0.6 μm. In some embodiments, the D 10 The particle size is about 0.4 μm to about 15 μm, e.g., about 0.4 μm to about 12 μm, about 0.4 μm to about 10 μm, about 0.4 μm to about 9 μm, about 0.4 μm to about 8 μm, about 0.45 μm to about 8 μm, about 0.5 μm to about 8 μm, about 0.55 μm to about 8 μm, or about 0.6 μm to about 8 μm. In some embodiments, the D of the Mn-containing precursor 10 The particle size is about 0.4 μm to about 2.0 μm, for example, about 0.5 μm to about 2.0 μm, or about 0.5 μm to about 1.0 μm.

[0075] In some embodiments, the Mn-containing precursor has a D of about 2.0 μm to about 4.0 μm. 90 Particle size: about 1.0 μm to about 1.5 μm D 50 particle size and D of about 0.5 μm to about 1.0 μm 10 In some embodiments, the Mn-containing precursor has a particle size of about 2.0 μm to about 3.0 μm. 90 Particle size: about 1.0 μm to about 1.5 μm D 50 particle size and D of about 0.5 μm to about 1.0 μm 10 It has a particle size.

[0076] Mn-containing precursors with the preferred particle size distribution are commercially available, for example, from Tropaq. Alternatively, the desired D 90can be obtained by grinding a precursor with a larger particle size until the correct particle size is reached, for example, using a grinding machine. The nature of the grinding machine is not particularly limited. It can be, for example, a ball mill, a planetary ball mill, a rolling bed mill, or a pearl mill.

[0077] In some embodiments, the D of the Ni-containing precursor 90 The particle size is less than 25 μm, e.g., less than 20 μm, or less than 15 μm. In some embodiments, the D 90 The particle size is 10 μm to 25 μm, for example, 10 μm to 20 μm, 10 μm to 15 μm, or 12 μm to 14 μm. In some embodiments, the D 50 The particle size is less than 15 μm, e.g., less than 10 μm, or less than 8 μm. In some embodiments, the D 50 The particle size is 5 μm to 15 μm, for example, 5 μm to 12 μm, 5 μm to 10 μm, or 5 μm to 8 μm. In some embodiments, the D 10 The particle size is less than 5 μm, e.g., less than 3 μm, less than 2 μm, less than 1 μm, or less than 0.8 μm. In some embodiments, the D 10 The particle size is 0.1 μm to 5 μm, for example, 0.2 μm to 5 μm, 0.5 μm to 2 μm, or 0.5 μm to 1 μm.

[0078] In some embodiments, the D of an M-containing precursor (e.g., an Al-containing precursor) 90 The particle size is less than 200 μm, e.g., less than 190 μm, less than 180 μm, less than 170 μm, or less than 160 μm. In some embodiments, the D of the M-containing precursor 90 The particle size is 120 μm to 200 μm, for example, 130 μm to 170 μm, 140 μm to 160 μm, or 145 μm to 155 μm. In some embodiments, the D of the M-containing precursor 50 The particle size is less than 120 μm, e.g., less than 115 μm, less than 110 μm, less than 105 μm, less than 100 μm, less than 95 μm, or less than 90 μm. 50The particle size is 50 μm to 120 μm, for example, 60 μm to 100 μm, 60 μm to 90 μm, or 80 μm to 90 μm. In some embodiments, the D of the M-containing precursor 10 The particle size is less than 60 μm, e.g., less than 55 μm, less than 50 μm, or less than 45 μm. In some embodiments, the D of the M-containing precursor 10 The particle size is 30 μm to 55 μm, for example, 35 μm to 55 μm, 35 μm to 50 μm, or 40 μm to 45 μm.

[0079] In step (b) of the process, the composition prepared in step (a) is subjected to grinding. Any suitable grinding equipment known to those skilled in the art can be used. The nature of the grinding equipment is not particularly limited. For example, it can be a ball mill, a planetary ball mill, a rolling bed mill, or a pearl mill. Grinding can be carried out until the particles reach the desired size. For example, the composition is typically ground to a size of less than 50 μm, e.g., less than 40 μm, less than 30 μm, or less than 20 μm. 50 The mixture is ground to a particle size.

[0080] The use of such a milling step means that larger particle size precursors can be used in the process with little or no negative impact on the structure or properties of the product, making the process more economical and more easily scalable as larger particle size precursors are cheaper.

[0081] Thus, in some embodiments, the process comprises: (a) preparing a composition comprising a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and optionally an M-containing precursor, wherein a single compound may optionally contain two or more of Mn, Ni, and M; (b) grinding the composition; and (c) calcining the product of step (b); wherein M is one or more elements selected from Al, Mg, Ti, Co, Cu, and Cr; The Mn-containing precursor, Ni-containing precursor, Li-containing precursor, and optional M-containing precursor may be converted to NO during calcination in step (c). x is selected so that substantially no gas is formed; The Mn-containing precursor has a D90 particle size of at least 10 μm, e.g., at least 20 μm, at least 30 μm, at least 40 μm, at least 50 μm, at least 60 μm, at least 70 μm, at least 80 μm, at least 90 μm, at least 100 μm, or at least 110 μm. In some embodiments, the Mn-containing precursor has a D10 particle size of at least 2 μm (e.g., at least 5 μm), a D50 particle size of at least 10 μm (e.g., at least 50 μm), and a D90 particle size of at least 10 μm (e.g., at least 80 μm). In this manner, a more economical process for preparing high-quality products is provided.

[0082] In some embodiments, the composition is a slurry, and the slurry is subjected to milling in step (b).

[0083] In some embodiments, the composition is ground in a pearl mill, which offers the advantage that the composition is in a circulating flow and is therefore ground several times.

[0084] In some embodiments, milling comprises milling in the presence of an inert milling medium, such as abrasive beads.

[0085] In some embodiments, the abrasive beads used in milling comprise zirconium oxide (ZrO2).

[0086] In some embodiments, the polishing beads have a diameter of less than 1 mm, e.g., less than 0.9 mm, less than 0.8 mm, or less than 0.7 mm. In some embodiments, 0.6 mm ZrO2 polishing beads are used.

[0087] In some embodiments, milling is carried out for at least 30 minutes, e.g., at least 45 minutes, at least 60 minutes, at least 75 minutes, at least 90 minutes, or at least 105 minutes. In some embodiments, milling is carried out for up to 5 hours, e.g., up to 4.5 hours, up to 4 hours, up to 3.5 hours, up to 3 hours, or up to 2.5 hours.

[0088] In some embodiments, milling is carried out for at least 2 hours. Such extended milling times allow for the use of larger particle size precursors without compromising product structure or properties, thereby providing a more economical process, as explained above.

[0089] In some embodiments, the slurry has a solids content of at least 10% by weight, e.g., at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, or at least 40% by weight, when added to the mill. In some embodiments, the slurry has a solids content of up to 80% by weight, e.g., up to 75%, up to 70%, up to 65%, up to 60%, up to 55%, or up to 50% by weight, when added to the mill. In some embodiments, the slurry has a solids content of 10-80% by weight, e.g., 10-70%, 20-70%, 30-70%, 30-60%, 40-60%, or 40-50% by weight, when added to the mill.

[0090] In some embodiments, the grinding speed in step (b) is at least 1000 rpm, e.g., at least 1500 rpm, at least 2000 rpm, or at least 2500 rpm. In some embodiments, the grinding speed is about 3000 rpm.

[0091] When the composition to be milled contains a solvent (ie, when the composition is a slurry), after milling in step (b), the milled slurry is dried.

[0092] Any suitable drying method known to those skilled in the art may be used, but preferably the slurry is spray dried, which makes the drying process easier to scale up.

[0093] Other possible drying methods include drying the slurry in a heated vacuum oven.

[0094] In some embodiments, the slurry is spray dried at a temperature of at least 150°C, e.g., at least 160°C, at least 170°C, at least 180°C, at least 190°C, at least 200°C, or at least 210°C. In some embodiments, the slurry is spray dried at a temperature of up to 280°C, e.g., up to 270°C, up to 260°C, up to 250°C, up to 240°C, or up to 230°C. In some embodiments, the slurry is spray dried at a temperature of 150-280°C, e.g., 160-270°C, 170-270°C, 180-270°C, 180-260°C, 180-250°C, 190-250°C, 190-240°C, 200-240°C, 200-230°C, or 210-230°C.

[0095] Those skilled in the art will appreciate that the temperature selection will depend on the scale of the spray drying process, with higher temperatures being possible for larger scale processes (eg, up to about 400° C.).

[0096] In some embodiments, the nozzle outlet temperature during the spray drying process is maintained at a temperature of 80-130° C., e.g., 80-120° C., 90-120° C., or 100-120° C. As will be appreciated by those skilled in the art, the outlet temperature can be adjusted by adjusting the pump speed.

[0097] The product of the drying step is a dry material which is calcined in step (c).

[0098] Calcination of the composition is carried out in step (c).

[0099] In some embodiments, during calcination, the material is exposed to a temperature of at least 350° C., e.g., at least 360° C., at least 370° C., at least 380° C., at least 390° C., at least 400° C., at least 410° C., at least 420° C., at least 430° C., or at least 440° C. In some embodiments, at least a portion of the calcination is carried out at a temperature of at least 750° C., e.g., at least 760° C., at least 770° C., at least 780° C., at least 790° C., at least 800° C., at least 810° C., at least 820° C., at least 830° C., or at least 840° C.

[0100] In some embodiments, during at least a portion of the firing, the material is exposed to a temperature of 350-950°C, e.g., 400-900°C, 440-860°C, 750-950°C, 760-940°C, 770-930°C, 780-920°C, 790-910°C, 800-900°C, 810-890°C, 820-880°C, 830-870°C, or 840-860°C. In some embodiments, during at least a portion of the firing, the material is exposed to a temperature of about 850°C. In some embodiments, during at least a portion of the firing, the material is exposed to a temperature of about 450°C.

[0101] In some embodiments, firing involves heating the material to an ambient temperature T0 up to a temperature T1 (with a rise time t 0-1 The heating is performed by heating the material at T1 (over a period of time t1) and holding the material at T1 for a time t1. In some embodiments, T1 is a temperature between 350 and 950°C, e.g., 400-900°C, 440-860°C, 750-950°C, 760-940°C, 770-930°C, 780-920°C, 790-910°C, 800-900°C, 810-890°C, 820-880°C, 830-870°C, or 840-860°C. In some embodiments, T1 is a temperature of about 850°C. T0 can be about room temperature.

[0102] In some embodiments, t1 is at least 10 minutes, e.g., at least 20 minutes, at least 30 minutes, at least 40 minutes, or at least 50 minutes. In some embodiments, t1 is up to 15 hours, e.g., up to 14.5 hours, up to 14 hours, up to 13.5 hours, up to 13 hours, up to 12.5 hours, or up to 12 hours. In some embodiments, t1 is between 20 minutes and 15 hours, e.g., between 1 hour and 15 hours, between 5 hours and 15 hours, or between 8 minutes and 13 hours. In some embodiments, t1 is about 12 hours.

[0103] In some embodiments, t 0-1 is about 1 to 10 hours, for example, about 2 to 8 hours, about 2 to 6 hours, about 3 to 6 hours, or about 5 hours.

[0104] Calcination can be carried out in any suitable calcination furnace, non-limiting examples of which include furnaces such as batch furnaces.

[0105] After firing, the material can be allowed to cool at ambient temperature.

[0106] The heating step may be carried out in air. In other embodiments, the calcination step may be carried out in a CO2-free atmosphere. For example, CO2-free air may flow over the material being calcined during calcination and, optionally, during cooling. The CO2-free air may be, for example, a mixture of oxygen and nitrogen. The CO2-free atmosphere may be oxygen (e.g., pure oxygen). Preferably, the atmosphere is an oxidizing atmosphere. As used herein, the term "CO2-free" is intended to include an atmosphere containing less than 100 ppm CO2, e.g., less than 50 ppm CO2, less than 20 ppm CO2, or less than 10 ppm CO2. These CO2 levels may be achieved by removing CO2 using a CO2 scrubber.

[0107] In some embodiments, the method further comprises a post-calcination step (d) of deagglomerating the calcined material, which in some embodiments comprises low-energy milling.

[0108] In some embodiments, the method further comprises sieving the material. In some embodiments, the method further comprises deagglomeration followed by sieving. In some embodiments, a sieve having an opening size of less than 60 μm, e.g., less than 55 μm or less than 50 μm, is used.

[0109] The process of the present invention may further include forming an electrode (typically a cathode) comprising the lithium manganese nickel spinel compound. Typically, this is done by forming a slurry of the particulate lithium manganese nickel spinel compound, applying the slurry to the surface of a current collector (e.g., an aluminum current collector), and optionally treating (e.g., calendering) the slurry to increase the density of the electrode. The slurry may include one or more of a solvent, a binder, a carbon material, and further additives.

[0110] Typically, the electrodes of the present invention have a density of at least 2.5 g / cm 3 , at least 2.8g / cm 3 , or at least 3 g / cm 3 This gives an electrode density of 4.5 g / cm 3 or less than 4g / cm 3 The electrode density may be the electrode density (mass / volume) of the electrode, not including the current collector on which the electrode is formed, and therefore includes the active material, any additives, any additional carbon material, and any remaining binder.

[0111] The process of the present invention may further include constructing a battery or electrochemical cell comprising an electrode comprising lithium nickel oxide. The battery or cell typically further comprises an anode and an electrolyte. The battery or cell may typically be a secondary (rechargeable) lithium (e.g., lithium-ion) ion battery.

[0112] A second aspect of the invention is a lithium manganese nickel spinel compound obtained or obtainable by a process according to the first aspect.

[0113] The lithium manganese spinel compounds are characterized by high initial capacity and high capacity retention. In some embodiments, the compounds exhibit excellent electrical conductivity at 23° C., a discharge rate of C / 2, and an electrode loading of 6 mg / cm. 2 The battery retains at least 92%, e.g., at least 92.5%, at least 93%, at least 93.5%, at least 94%, at least 94.5%, at least 95%, or at least 95.5% of its capacity after 200 cycles at 1000 rpm.

[0114] In some embodiments, the compound provides an initial capacity of at least 125 mAh / g, e.g., at least 126 mAh / g, at least 127 mAh / g, at least 128 mAh / g, at least 129 mAh / g, at least 130 mAh / g, at least 131 mAh / g, at least 132 mAh / g, at least 133 mAh / g, at least 134 mAh / g, or at least 135 mAh / g.

[0115] A third aspect of the present invention provides a positive electrode active material comprising a compound according to the second aspect.

[0116] A fourth aspect of the present invention provides an electrode comprising a material according to the third aspect.

[0117] A fifth aspect of the present invention provides a lithium secondary battery comprising an electrode according to the fourth aspect.

[0118] Another aspect of the invention is the use of a compound according to the second aspect in a lithium secondary cell or battery.

[0119] The present invention will now be described with reference to the following examples, which are provided to aid in the understanding of the invention and are not intended to limit its scope. [Example]

[0120] Example 1 - LiMn from hydroxide and carbonate precursors 1.55 Ni 0.4 Al 0.05 Preparation of O4 58.4 g of LiOH.HO (SQM) was dissolved in 250 mL of HO. Ni(OH) (Todini GmbH, D50 = 5.9 μm) and Al(OH) (Clariant, D90 = 152.77 μm, D50 = 87.63 μm, D10 = 43.29 μm) were added along with an additional 50 mL of HO, and the slurry was mixed using an Ultra Turrax disperser at 3000 rpm for 30 min.

[0121] MnCO3 with a D90 particle size of 2.5 μm, a D50 particle size of 1.23 μm, and a D10 particle size of 0.62 μm (Tropaq UF, Clariant) was added and the slurry was mixed at 6000 rpm for an additional 20 min. The particle size distribution of the MnCO3 powder is shown in Figure 8(a).

[0122] Then, 1.14 g of H3BO3 and 2.3 g of LiOH were thoroughly mixed in a pestle and mortar and added to the slurry along with an additional 300 mL of H2O.

[0123] The slurry was then milled in a pearl mill for 2 hours. The chamber was 80% filled with 0.6 mm ZrO2 balls, and the slurry had a solids content of 42 wt. %. The mill speed was 3000 rpm, and the pump speed was 2500 rpm.

[0124] After milling, the slurry was spray dried at 220°C using a Buchi lab spray dryer, adjusting the pump speed to maintain an outlet temperature of 110°C. The collected powder was then calcined in air using a Nabertherm batch furnace by heating to 850°C over 5 hours and then holding at 850°C for 12 hours. After calcination, the powder was removed from the furnace and allowed to cool to ambient temperature. The powder was then lightly milled in a Fritsch mill to deagglomerate it and passed through a 45 μm sieve.

[0125] The product, herein designated "Sample A," was found to have a D50 particle size of 5.68 μm. A typical particle size distribution is shown in Figure 9(a).

[0126] Figure 9(b) shows an SEM image of the lithium manganese nickel spinel material prepared in Example 1. Figure 10 shows the XRD plot of the material.

[0127] Example 2 - LiMn from hydroxide and carbonate precursors 1.55 Ni 0.4 Al 0.05 Preparation of O4 The method of Example 1 was followed, except that the MnCO precursor used had a D90 particle size of 113.6 μm, a D50 particle size of 60.61 μm, and a D10 particle size of 7.84 μm (Tropaq HP, Clariant). The particle size distribution of the MnCO powder is shown in Figure 8(b). The product is referred to herein as "Sample B."

[0128] Comparative Example 1 - LiMn from Nitrate and Carbonate Precursors 1.55 Ni 0.4 Al 0.05 Preparation of O4 Mn(NO3)2.4H2O, Ni(NO3)2.6H2O, and Al(NO3)3.9H2O were dissolved in deionized water for 30 minutes using an Ultra Turrax mixer. Separately, LiOH.H2O was dissolved in deionized water along with H3BO3. The LiOH / H3BO3 solution was then added dropwise to the mixed metal nitrate solution. The suspension was mixed in the Ultra Turrax mixer for 10 minutes, then in a Pendraulik mixer for 60 minutes.

[0129] MnCO3 with a D90 particle size of 2.5 μm, a D50 particle size of 1.23 μm, and a D10 particle size of 0.62 μm (Tropaq UF) was added, and the suspension was then mixed for an additional hour. The suspension was then milled in a bead mill for 1 hour. The grinding chamber was filled 75% with 1.3 mm ZrO2 balls, and the solids content of the suspension was 50%. Milling was carried out for 3 x 20-minute periods, with a 20-minute rest period between each milling period.

[0130] The milled suspension was spray dried at 220 °C, maintaining the pump rate to keep the outlet temperature at approximately 110 °C. The collected powder was then calcined in air at 450 °C for 1 h and then at 850 °C for 12 h. After calcination, the powder was lightly crushed to deagglomerate it and passed through a 45 μm sieve.

[0131] The product, herein designated "Sample C," was found to have a D90 particle size of 11.01 μm, a D50 particle size of 4.79 μm, and a D10 particle size of 1.68 μm.

[0132] Comparative Example 2 - LiMn from Nitrate and Carbonate Precursors 1.55 Ni 0.4 Al 0.05 Preparation of O4 The method of Comparative Example 1 was followed, except that the MnCO3 precursor used had a D90 particle size of 113.6 μm, a D50 particle size of 60.61 μm, and a D10 particle size of 7.84 μm (Tropaq HP).

[0133] The product, herein designated "Sample D", was found to have a D90 particle size of 13.50 μm, a D50 particle size of 5.65 μm, and a D10 particle size of 2.13 μm.

[0134] Comparative Example 3 - LiMn from Nitrate and Carbonate Precursors 1.55 Ni 0.4 Al 0.05 Preparation of O4 The method of Comparative Example 1 was followed, except that the MnCO precursor used had a D90 particle size of 113.6 μm, a D50 particle size of 60.61 μm, and a D10 particle size of 7.84 μm (Tropaq HP). Additionally, after addition of the MnCO, milling in the bead mill was carried out for 4 hours instead of 1 hour.

[0135] The product, herein designated "Sample E", was found to have a D90 particle size of 12.73 μm, a D50 particle size of 5.98 μm, and a D10 particle size of 2.47 μm.

[0136] Comparative Example 4 LiMn from nitrate and carbonate precursors 1.55 Ni 0.4 Al 0.05 Preparation of O4 Mn(NO3)2.4H2O, Ni(NO3)2.6H2O, and Al(NO3)3.9H2O were dissolved in deionized water for 30 minutes using an Ultra Turrax mixer. Separately, LiOH.H2O was dissolved in deionized water along with H3BO3. The LiOH / H3BO3 solution was then added dropwise to the mixed metal nitrate solution. The suspension was mixed in the Ultra Turrax mixer for 10 minutes, then in a Pendraulik mixer for 60 minutes.

[0137] MnCO3 with a D90 particle size of 54.17 μm, a D50 particle size of 31.74 μm, and a D10 particle size of 18.07 μm (Tropaq Type N) was added, and the suspension was then mixed for an additional hour. The suspension was not subjected to any milling or grinding. The PSD of Tropaq Type N MnCO3 is provided in Figure 12.

[0138] The suspension was spray dried at 220°C, and the pump rate was maintained to maintain an outlet temperature of approximately 110°C. The collected powder was then calcined in air at 450°C for 1 hour, then at 850°C for 12 hours. After calcination, the powder was lightly crushed to deagglomerate it and passed through a 45 μm sieve. The product is referred to herein as "Sample F."

[0139] Electrochemical Testing Electrodes were fabricated using a 40% solids ink with a 90:5:5 active material:carbon:binder blend. A 10 wt% solution of polyvinylidene fluoride (PVdF; Solvay Solexis Solef 5130) in N-methylpyrrolidone (NMP, ex. Aldrich) was prepared. 2 g of this solution was extracted and 3.5 g of NMP was added. 0.2 g of carbon black (Timcal, Super P Li) was added, and the composition was mixed for 1 hour at 4000 rpm using a tube drive. 3.6 g of the active material prepared in the above examples and comparative examples was added, and the mixture was further mixed for 1 hour at 4000 rpm using a tube drive.

[0140] The resulting ink was deposited onto aluminum foil using a fixed blade coater to provide a foil coated on both sides with a wet thickness of 170 μm. The foil was pre-dried on a heating plate at 50°C and then dried under vacuum at 120°C for 120 minutes. After drying, the electrode sheet was cut into 13 mm diameter (1.33 cm area) foils. 2 The electrode was then cut into 10 t / cm 2 electrodes and further dried in vacuum at 160°C overnight. 2 The electrode was compacted twice for 1 min at a static pressure of 0.05 MPa. The thickness of the dried and compacted electrode was 45 μm, and the typical loading of active material was 5-10 mg / cm. 2 It was.

[0141] Tests were performed in half cells with a 15 mm lithium foil disk as the counter electrode, a PSI glass fiber separator, and 0.4 mL of electrolyte composed of fluorinated ethylene carbonate (FEC):DMC in a volume ratio of 1:4. Galvanostatic cycling tests were performed at C / 2 vs. Li / Li between 3.0 V and 5.1 V. + This was performed by cycling the cells at a ratio of 0.1:1.

[0142] The specific capacity of the three different materials is plotted against discharge rate in Figure 1. The plot shows the specific capacity of the materials prepared in Comparative Examples 1, 2, and 3 (Samples C, D, and E, respectively). The plot shows that to match the capacity and rate performance of the material in Comparative Example 1 (prepared from a smaller particle size Mn precursor), the milling time must be increased by 1 to 4 hours when a larger Mn precursor particle size is used. In other words, 4 hours of milling was required to achieve the same degree of uniformity in the material prepared from the larger particle size Mn precursor.

[0143] Figure 2 is a plot of the cycle life of the materials of Comparative Examples 1, 2, and 3 (Samples C, D, and E, respectively). The results show that to match the cycle life of the material of Comparative Example 1 (prepared from a smaller particle size Mn precursor), the milling time must be increased by 1 to 4 hours when a larger Mn precursor particle size is used.

[0144] Figure 3 shows the discharge curves of the materials of Comparative Examples 1, 2, and 3 (Samples C, D, and E, respectively). The results show that the materials of Comparative Examples 1 and 3 have comparable specific energies, while the material of Comparative Example 2 has a lower specific energy, which is consistent with the results shown in Figures 1 and 2. Figure 3 also shows that the Mn(III) plateau at 4.0 V is longer for Comparative Examples 2 and 3 than for Comparative Example 1, indicating that the Mn precursor in Comparative Examples 2 and 3 was partially oxidized during the fabrication process.

[0145] 4 plots the specific capacity of the materials of Example 1 and Comparative Example 1 (Samples A and C, respectively). The results show that the capacity of the material of Example 1 is higher than that of the material of Comparative Example 1.

[0146] Figure 5 shows that the rate capabilities of the materials of Example 1 and Comparative Example 1 (Samples A and C, respectively) were comparable. The results, shown in Figure 6, reveal no difference in life cycle performance over the test period (25 cycles).

[0147] Thus, compared to existing processes that use nitrate precursors, it is possible to obtain phase-pure materials with similar particle size, higher capacity, and comparable rate capability and cycle life using the process of the present invention. x No gases are produced and therefore no exhaust gas treatment is required.

[0148] FIG. 7 shows the specific capacitance of the materials of Example 1 and Example 2 (Samples A and B, respectively).

[0149] XRD showed that a single phase was formed in both Examples 1 and 2 with comparable lattice parameters. This suggests that the same amounts of Ni and Al were incorporated into the lattice despite the change in precursor. However, the results in Figure 7 show that the material of Example 2, made using the larger MnCO precursor, has a lower capacity (128 mAh / g) than that of Example 1 (134 mAh / g). This may be due to some oxidation of Mn(II) to Mn(III) during the preparation of the product of Example 2.

[0150] Figure 11 shows the discharge curves of the material of Comparative Example 4 at five different discharge rates: D / 5 (5 hours), 1D (1 hour), 3D (20 minutes), 5D (12 minutes), and 10D (6 minutes). Compared to the material of the present invention, the discharge curves in Figure 11 show a shorter, high-voltage plateau, indicating a relatively lower specific capacity and lower specific energy even at low discharge rates.

Claims

1. 1. A process for preparing a particulate lithium manganese nickel spinel compound, said process comprising: (a) preparing a composition comprising a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and optionally an M-containing precursor, wherein a single compound may optionally contain two or more of Mn, Ni, and M; (b) grinding the composition; and (c) calcining the product of step (b); M is one or more elements selected from Al, Mg, Ti, Co, Cu, and Cr; the Mn-containing precursor, the Ni-containing precursor, the Li-containing precursor, and the optional M-containing precursor are selected such that substantially no NOx gases are formed during the calcination in step (c); A process wherein the D 90 particle size of the Mn-containing precursor is less than 4 μm, such as less than 3 μm or less than 2.5 μm.

2. 10. The process of claim 1, wherein the amount of NOx produced during the calcination is such that the concentration of NOx in the exhaust gas from the calcination is less than 50 ppm.

3. 3. The process of claim 1 or 2, wherein each of the Mn-containing precursor, Ni-containing precursor, Li-containing precursor, and optional M-containing precursor is substantially nitrate-free, e.g., contains less than 5 wt. % nitrate based on the weight of the metal element in the precursor.

4. D of the Mn-containing precursor ５０ The process of any one of claims 1 to 3, wherein the particle size is less than 2 μm.

5. D of the Mn-containing precursor １０ The process of any one of claims 1 to 4, wherein the particle size is less than 1 μm.

6. The Mn-containing precursor has a D of about 2.0 μm to about 4.0 μm. ９０ Particle size, D of about 1.0 μm to about 1.5 μm ５０ particle size, and D of about 0.5 μm to about 1.0 μm １０ The process of any one of claims 1 to 5, wherein the particle size is

7. The particulate lithium manganese nickel spinel compound has a D of about 1.0 μm to about 3.0 μm. １０ The process of any one of claims 1 to 6, wherein the particle size is

8. The particulate lithium manganese nickel spinel compound has a D of about 8.0 μm to about 15.0 μm. ９０ The process of any one of claims 1 to 7, wherein the particle size is

9. The Mn-containing precursor is MnCO ３ The process according to any one of claims 1 to 8, comprising:

10. The Ni-containing precursor is Ni(OH). ２ or a hydrated form thereof.

11. The process of any one of claims 1 to 10, wherein the Li-containing precursor comprises LiOH or a hydrated form thereof.

12. 12. The process of any one of claims 1 to 11, wherein the composition is a slurry comprising a solvent, the Mn-containing precursor, the Ni-containing precursor, the Li-containing precursor, and optionally the M-containing precursor.

13. 13. The process of claim 12, further comprising the step of drying the slurry after said grinding step (b) and before said calcining step (c), said drying preferably comprising spray drying.

14. 14. The process of claim 12 or 13, wherein step (a) comprises preparing a slurry comprising a solvent, a Mn-containing precursor, a Ni-containing precursor, a Li-containing precursor, and a M-containing precursor.

15. The M-containing precursor is an Al-containing precursor, preferably Al(OH). ３ The process according to any one of claims 1 to 14, comprising:

16. The process of any one of claims 1 to 15, wherein step (b) is carried out in a pearl mill.

17. The process of any one of claims 1 to 16, wherein in step (c), the calcination is carried out at a temperature of from 350 to 950°C.

18. the particulate lithium manganese nickel spinel compound has a composition according to Formula I, Li ｘ Mn ｙ Ni ｚ M ａ O ｂ Formula I wherein M is one or more elements selected from Al, Mg, Ti, Co, Cu, and Cr; 0.8≦x≦1.2, y=2−z−a, 0.2<z<1.2, 0≦a≦0.06, The process of any one of claims 1 to 17, wherein 3.5≦b≦4.

5.

19. 0.9≦x≦1.1, 0.3<z<0.5, 0.04≦a≦0.06, 3.9≦b≦4.1, 20. The process of claim 18, wherein M is Al.

Images