Method for preparing monodisperse single-crystal cathode materials

Abstract

The method includes providing a metal salt solution including nickel, cobalt, manganese, aluminum, or a combination thereof; combining the metal salt solution with a basic solution, wherein the combined metal salt solution and basic solution are maintained at a pH of 10 or less to form a metal hydroxide precursor. To form a cathode active material, the method further includes adding a lithium compound to the metal hydroxide precursor to form a metal hydroxide precursor mixture; and heat-treating the metal hydroxide precursor mixture to form a single crystal cathode active material.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 404,579, filed September 8, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] The field of the invention is methods for making single crystal cathode active materials. [Background technology]

[0003] Single-crystal cathode active materials (CAMs) for lithium-ion batteries may have advantages over conventional layered oxide cathode active materials. For example, single-crystal cathode active materials (sometimes referred to as single-crystal monolithic cathode active materials) can have one or more of higher mechanical strength, structural stability, thermal stability, and longer cycle life compared to polycrystalline cohesive cathode active materials.

[0004] Previous attempts to produce single-crystal CAM have involved co-precipitation followed by multiple calcination or annealing steps. See, for example, International Publication No. 2020 / 082019. Particle size control can be difficult. Therefore, co-precipitation methods sometimes involve milling the first calcined particles, followed by one or more additional annealing steps. See, for example, International Publication No. 2022 / 026014. Other methods include the use of molten salts, sol-gel processing, and hydrothermal reactions.

[0005] A simplified process that provides monodisperse single crystal particles of a desired size would be an advancement in the art. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2020 / 082019 [Patent Document 2] International Publication No. 2022 / 026014 Summary of the Invention

[0007] Disclosed herein is a method of making a single crystal cathode active material, the method including: providing a metal salt solution including nickel, cobalt, manganese, aluminum, or a combination thereof; combining the metal salt solution with a basic solution, wherein the combination of the metal salt solution and the basic solution is maintained at a pH of 10 or less to form a metal hydroxide precursor; adding a lithium compound to the metal hydroxide precursor to form a metal hydroxide precursor mixture; and heat-treating the metal hydroxide precursor mixture to form a single crystal cathode active material.

[0008] Also disclosed is a method of making a monodisperse single crystal cathode active material, comprising: providing a metal hydroxide precursor comprising nickel, cobalt, manganese, aluminum, or a combination thereof, wherein the metal hydroxide precursor is characterized as being semi-crystalline and in the beta phase, such as CuK α Also disclosed herein is a method for producing a cathode active material comprising a beta phase characterized by a peak at 17 to 23 degrees 2θ when analyzed by X-ray diffraction using X-rays, and a mesophase characterized by HO, ROH, RCOOH, anions, or combinations thereof incorporated into the structure of the mesophase, where R is an alkyl group of 1 to 3 carbon atoms; adding a lithium compound to a metal hydroxide precursor to form a mixture; and heating the mixture in a single-step calcination to form a monodisperse single crystalline cathode active material having a unimodal particle size distribution and a D50 particle size distribution of 100 nanometers (nm) to 5 micrometers (μm) or a D90 particle size distribution of 1 to 10 μm.

[0009] Further, the present invention provides a metal hydroxide composition comprising: a metal hydroxide comprising nickel, cobalt, manganese, aluminum, or a combination thereof, wherein the metal hydroxide is characterized as being semi-crystalline, having a beta phase, and wherein the beta phase is CuK. αWhen analyzed by X-ray diffraction using a line, it is characterized by a peak at 17 to 23 degrees 2θ, has the formula M(OH)2, where M is Ni, Co, Mn, Al, or a combination thereof, a beta phase, and an intermediate phase, wherein H2O, ROH, RCOOH, an anion, or a combination thereof is incorporated into the structure of the intermediate phase, and R is an alkyl group having 1 to 3 carbon atoms. A metal hydroxide composition containing the intermediate phase is disclosed herein.

[0010] Also, a single crystal cathode active material having the formula Li x MO2, wherein M is Ni, Co, Mn, Al, or a combination thereof, 0 < x ≦ 1.2, a unimodal particle size distribution and a D50 particle size distribution of 100 nm to 5 μm, or a D90 particle size distribution of 1 to 10 μm, and the presence of Li2SO4, is also disclosed.

[0011] Here, reference is made to the drawings, which are exemplary embodiments and like elements are numbered alike.

Brief Description of the Drawings

[0012] [Figure 1] Scanning electron micrograph (SEM) of the coprecipitated particles of Example 1.

[0013] [Figure 2] SEM of the coprecipitated particles of Example 2.

[0014] [Figure 3] SEM of the coprecipitated particles of Example 3.

[0015] [Figure 4] SEM of the coprecipitated particles of Example 4.

[0016] [Figure 5] SEM of the coprecipitated particles of Example 5.

[0017] [Figure 6A] 10 is an SEM image of cathode active material particles according to Example 6.

[0018] [Figure 6B] 10 is an SEM image of cathode active material particles according to Example 6.

[0019] [Figure 7] 1 is a graph of intensity (arbitrary units) versus diffraction angle (2θ degrees) showing the results of X-ray diffraction (XRD) analysis when the mixed metal hydroxides of Comparative Example 1 and Examples 1 to 4 were analyzed using Cu Kα radiation.

[0020] [Figure 8] 1 is a graph of intensity (arbitrary units) versus diffraction angle (2θ degrees) showing an X-ray diffraction (XRD) analysis of the mixed metal hydroxide of Example 5 when analyzed using Cu Kα radiation.

[0021] [Figure 9] 1 is a graph of intensity (arbitrary units) versus diffraction angle (2θ degrees) showing the results of X-ray diffraction analysis of the cathode active material of Example 6 using Cu Kα radiation.

[0022] [Figure 10] 1 is a graph of intensity (arbitrary units) versus diffraction angle (2θ degrees) showing an X-ray diffraction analysis of the cathode active material of Example 7 when analyzed using Cu Kα radiation.

[0023] [Figure 11] 1 is a graph of distribution density versus particle size (micrometers, μm) showing the particle size distribution of cathode active material particles synthesized in Example 6.

[0024] [Figure 12] 1 is a graph of distribution density versus particle size (micrometers, μm) showing the particle size distribution of cathode active material particles synthesized in Comparative Example 2.

[0025] [Figure 13]1 is a graph of intensity (arbitrary units) versus diffraction angle (2θ degrees) showing the results of X-ray diffraction analysis when the cathode active material of Comparative Example 2 was analyzed using Cu Kα radiation. DETAILED DESCRIPTION OF THE INVENTION

[0026] The methods disclosed herein provide an efficient means for producing monodisperse single crystal cathode active materials without the need for multiple firing or annealing steps, milling, complex chemistries, or high-energy processes often associated with sol-gel, molten salt, or hydrothermal methods.

[0027] In particular, it has been found that careful control of the pH during coprecipitation of metal sulfate solutions leads to unique metal hydroxide precursors that can be easily mixed with lithium compounds and calcined to produce small, monodisperse, single-crystal cathode active material particles. Calcination can be performed in a single step, although additional steps are not excluded.

[0028] metal hydroxide The metal hydroxide precursors formed or used by the methods disclosed herein can be characterized as including a beta phase and an intermediate phase. The beta phase can be characterized by X-ray diffraction (XRD) as showing peaks within the range of 17 - 23 degrees 2θ when analyzed using Cu Kα radiation. The beta phase can be crystalline, amorphous, or can include a combination of crystalline and amorphous particles. The beta phase can have the formula M(OH)2, where M is a metal. For example, the metal M can be nickel, cobalt, manganese, aluminum, or a combination thereof. As another example, the metal can include nickel, cobalt, and manganese in a molar ratio of greater than 0 to 1 mole of nickel: greater than 0 to 1 mole of cobalt: greater than 0 to 1 mole of manganese; or preferably, 1 mole of nickel: 0.1 - 0.2 moles of cobalt: 0.1 - 0.2 moles of manganese. For example, the nickel: cobalt: manganese molar ratio can be 1:0.125:0.125, or 1:0.18:0.18.

[0029] The X-ray diffraction pattern can also, alternatively, or in some examples, show an alpha phase. The alpha phase is characterized by peaks within the range of 5 - 15 degrees 2θ when analyzed by X-ray diffraction using Cu K α radiation. X-ray diffraction can be measured using a commercially available X-ray diffractometer such as a Rigaku TM Miniflex. <​​​​- , SO4 2- , NO3 - , CO3 2- , F - , Cl - , or a combination thereof. Z is preferably water or sulfate ion, more preferably water. The Z element is incorporated into the structure of the mesophase. In one embodiment, O <y<0.75、0.1<y<0.65、または0.2<y<0.55である。

[0031] The metal hydroxide precursor can include residual sulfur in an amount of at least 0.1 weight percent (wt%) to less than 3 wt% residual S content, preferably less than 2.5 wt%, and more preferably less than 2 wt%, each based on the total weight of the metal hydroxide precursor.

[0032] In one embodiment, the metal hydroxide precursor has a tap density of 0.1 grams per cubic centimeter (g / cc) to 1.5 g / cc, preferably 0.1 to 1 g / cc, and more preferably 0.1 to 0.5 g / cc. Tap density may be determined according to ASTM B527, the contents of which are incorporated herein by reference in their entirety.

[0033] Method for preparing metal hydroxides To prepare the metal hydroxide precursor, a metal salt solution can be provided. The metal salt solution can be combined with a basic solution to cause precipitation of the metal hydroxide precursor. The metal salt solution includes a metal salt of nickel, cobalt, manganese, aluminum, or a combination thereof.

[0034] For example, the metal salt solution can be a metal sulfate solution, a metal hydroxide solution, or a metal nitrate solution. The metal salt solution can contain one metal or a mixture of two or more metals. In the solution, the metal(s) are present in ionic form. In one embodiment, the metal salt solution is an aqueous solution of a sulfate salt. The sulfate salt may include nickel sulfate, manganese sulfate, cobalt sulfate, aluminum sulfate, or a combination thereof. Examples include the use of NiSO4·6H2O-, MnSO4·H2O, and CoSO4·7H2O.

[0035] The concentration of the metal salt in the metal salt solution can be, for example, 0.2 to 2.2 moles of metal salt per kilogram (molar) of solvent, or 0.2 to 3 moles of metal salt per liter (molar) of solution. The solvent in the metal salt solution can include water. The metal salt solution can include metals obtained from recycled feedstocks, preferably post-industrial recycled feedstocks, post-consumer recycled feedstocks, or combinations thereof. In one embodiment, the nickel, cobalt, manganese, aluminum, or combinations thereof of the metal salt solution are obtained from recycled feedstocks.

[0036] The basic solution can include an alkali metal hydroxide, ammonium hydroxide, or a combination thereof. Any suitable alkali metal hydroxide can be used. The alkali metal can be Li, Na, K, Rb, Cs, Fr, or a combination thereof. For example, the alkali metal hydroxide and ammonium hydroxide can be present in a molar ratio of 2:1 to 1:2, or 1.5:1 to 1:1.5, or 1.2:1 to 1:1. When the basic solution includes a combination, a separate solution can be added to the metal salt solution, or the basic solution can be precombined and then combined with the metal salt solution. The ammonia concentration can be 0.2 to 20 molar, or 0.2 to 19 molar. The alkali hydroxide concentration can be 0.2 to 20 molar, or 0.2 to 30 molar.

[0037] The basic solution(s) and the metal salt solution can be combined in a batch mode. Alternatively, one of the metal salt and basic solution can be placed in a vessel and the other solution can be added as a continuous feed. As yet another example, both the basic solution(s) and the metal salt solution(s) can be added continuously to a vessel.

[0038] The pH of the combination of the metal salt solution and the basic solution is 10 or less, preferably less than 10. At higher pHs, no alpha or mesophases are observed by X-ray diffraction. At pH 7-8, the alpha phase is observed, and mesophases and beta phases may not be observed. At a pH of at least 8 to 10, useful combinations of beta and mesophases are observed. Thus, the pH of the combination of the metal salt solution and the basic solution can be at least 8, or at least 8.5, or at least 9, or at least 9.5, or up to 10, or up to 9.5, or up to 9, or up to 8.5.

[0039] The combination can be heat-treated at a temperature ranging from 25 to 60°C. The combination can be stirred, for example, in a continuous stirred tank reactor. The stirring speed can be in the range of 200 to 1000 RPM. The metal hydroxide formed in the combined solution can have a solids loading of 2 to 20 wt. %, preferably 5 to 15 wt. %, and more preferably 8 to 15 wt. %, based on the total weight of the combined solution. The metal hydroxide precipitate can be collected by any suitable solid-liquid separation technique, such as filtration, centrifugation, decantation, or other suitable solid / liquid separation process, or a combination thereof. The isolated precipitate can be washed. Washing can reduce the conductivity of the filtrate to a desired level, for example, to less than 400 microsiemens per centimeter (μS / cm), or to less than 350 μS / cm.

[0040] Method for preparing monodispersed single-crystal cathode active material The metal hydroxides described above can be used to form the cathode active material. In particular, a lithium compound can be added to the metal hydroxide to form a mixture that is then heated to form the cathode active material.

[0041] Surprisingly, it has been discovered that small, unimodal, monodisperse, single-crystal cathode active materials can be formed in a single heating step when the metal hydroxide comprises a beta phase and an interphase. Without wishing to be bound by theory, it is possible that the beta phase acts as a nucleus and the interphase functions as a particle growth agent that promotes particle growth during heating (e.g., calcination).

[0042] The lithium compound can include lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, or a combination thereof. The molar ratio of the lithium compound to the metal hydroxide compound can be 1 to 1.2, preferably 1.02 to 1.15, or more preferably 1.05 to 1.10.

[0043] The heating step can include calcination or sintering and can include heating at a temperature of 600 to 1100°C, preferably 800 to 1000°C, and more preferably 850 to 950°C. Heating can be performed, for example, for 2 to 24 hours. While a single heating step has been found to form small, monomodal, monodispersed single-crystal cathode active materials, additional heating steps can be used. In some examples, the mixture subjected to heating can include 0.1 to 4 wt. % lithium carbonate, based on the total weight of the mixture. In some embodiments, the additional heating step is excluded from the method.

[0044] The method can further include washing the cathode active material after heating. Washing can be performed with any suitable liquid, such as water or C 1-4 This may include washing with an aqueous solution of water containing an alcohol (e.g., methanol, ethanol, isopropanol, butanol).

[0045] Monodispersed single-crystal cathode active material The monodisperse single-crystal cathode active material formed by the above method can have the formula Li x MO2, where M is Ni, Co, Mn, Al, or a combination thereof, and 0 < x ≦ 1.2. For example, the single-crystal cathode active material can be Li x Ni y Co z Mn v O2, where 0 < x ≦ 1.2 and 0.8 ≦ (y + z + v) ≦ 1.1. In one example, y can be from 0.1 to 1, z can be from 0.01 to 0.1, v can be from 0.01 to 0.1, preferably y can be from 0.5 to 1, z can be from 0.02 to 0.1, and v can be from 0.02 to 0.1. As a specific example, y can be from 0.7 to 1, z can be from 0.02 to 0.1, and v can be from 0.02 to 0.1. In one aspect, the single-crystal cathode active material can have the formula LiNi 0.88 Co 0.06 Mn 0.06 O2.

[0046] The single-crystal cathode active material can have a unimodal particle size distribution, can be monodisperse, and can have a small particle size. For example, the D50 particle size can be at least 100 nanometers (nm) to less than 20 micrometers (μm). Within this range, the D50 particle size can be 500 nm to 10 μm, or 1 to 5 μm, or 1 to 3 μm. The D90 particle size can be 1 to 20 μm. Within this range, the D90 particle size can be 3 to 20 μm, or 5 to 8 μm. The particle size and distribution can be determined using a particle size analyzer, such as a HELOS-RODOS model H3365. The particle size can be determined using the wet method. The D50 particle size represents the median diameter, that is, the particle size at 50% cumulative distribution. The D90 particle size represents the particle size at 90% cumulative distribution and means that 90% or the particles are smaller than this size. The D50 particle size, D90 particle size, and particle size distribution can be determined according to ASTM C115, the content of which is incorporated herein by reference in its entirety.

[0047] Single crystal active materials made according to the methods disclosed herein using sulfate salts can have residual Li2SO4. The presence of sulfate salts can be seen in Figure 9, where Cu K α When analyzed using X-rays, the value may be determined from the X-ray diffraction peak at 22 to 29 degrees 2θ.

[0048] The cathode active material contains less than 10 wt % or less than 7 wt % residual lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, lithium sulfate, or a combination thereof on the surface of the cathode active material, based on the total weight of the cathode active material. For example, the cathode active material may contain 0 to 10 wt %, or 0 to 7 wt %, or 0 to 5 wt %, or 0 to 3 wt %, or greater than 0 to 10 wt %, or greater than 0 to 7 wt %, or greater than 0 to 5 wt %, or greater than 0 to 3 wt % residual lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, lithium sulfate, or a combination thereof on the surface of the cathode active material, each based on the total weight of the cathode active material.

[0049] In one embodiment, the cathode active material is characterized by an average discharge capacity of greater than 200 milliamp-hours per gram (mAh / g) at a C / 3 discharge rate for half cells over 100 cycles. The half cells may use a lithium metal anode. The C / 3 rate refers to the current that discharges the battery in 3 hours and can be determined using a cathode active material specific capacity of 230 mAh / g.

[0050] Electrode and cell formation method The cathode active materials disclosed herein can be used to form cathodes by combining the cathode active material with a conductive material such as carbon black and a binder material such as a suitable polymeric material (e.g., polyvinylidene fluoride, a cellulosic polymer, etc.) and applying the combination to a current collector. The combination can be in the form of a slurry including a carrier solvent such as N-methylpyrrolidone (NMP). The electrode can be used in energy storage devices. [Example]

[0051] Test Method: Particle size distribution (PSD) was characterized in the examples using a HELOS&RODOS model H3365 (software PAQXOS 5.1.1) particle size analyzer. For analysis, less than 100 milligrams (mg) of powder was dispersed in 20 milliliters (mL) of water and sonicated for 1 minute before analysis. Standard measurement ranges (e.g., R3 and R5: 0.5-875 μm) were used for measurements. For X-ray diffraction (XRD) analysis, Rigaku TM A Miniflex was used in the examples. A voltage of 40 kV and a Cu radiation source of 15 mA were used. The wavelengths of Ka1 and Ka2 were 1.54059 Å and 1.54441 Å, respectively. Scan conditions were: 1D scan (θ / 2θ, D / tex Ultra detector) with a step width of 0.01° and a scan rate of 10° / min. The scan range was 5 to 80 degrees 2θ.

[0052] Scanning electron micrographs, Phenon TM Images were collected using an XL microscope. The accelerating voltage was 15 kV at a magnification of 20,000–25,000x. Backscattering mode was used for all images.

[0053] Residual Li determination was performed using a Metrohm ion exchanger to measure the residual lithium content in the cathode active material. TM The samples were characterized by automatic titration. HCl (0.1 normal (N)) standard was used for the titration, and two titration endpoints were detected. The two endpoint pH values ​​corresponded to 8.1 and 4.4, respectively. The lithium hydroxide and lithium carbonate contents (wt%) could be determined by the volume of HCl required to reach the first and second titration endpoints.

[0054] Electrode preparation: Cathode active material (CAM) powder was mixed with conductive carbon black and PVDF binder in a weight ratio of 94:3:3. The mixture was mixed in a THINKY MIXER with N-methyl-2-pyrrolidone (NMP) to adjust the rheology of the slurry. TMMixing was performed using a planetary mixer. Mixing conditions: 10 cycles of 1 minute at 2000 RPM with a 1-minute rest period between cycles. The slurry was then cast onto Al foil using a 254 mm doctor blade, followed by drying at 60 °C to remove most of the NMP solvent, followed by drying at 120 °C for 5 minutes. The cast film was then further dried at 110 °C overnight and under vacuum for at least 12 hours to ensure proper drying and PVDF curing. Coin half cells (CR2032) with a Li metal anode were assembled using an electrolyte containing 1.2 M LiPF6 in ethylene carbonate (EC):ethyl methyl carbonate (EMC) (3:7 v / v%) + 2 wt% vinylene carbonate (VC) and tested using an Arbin tester.

[0055] Electrochemical test protocol: The coin half cells were first charged using a constant current / constant voltage (CC-CV) protocol at a C / 10 constant charge current to a cutoff voltage of 4.3 V, followed by constant voltage charging until the charge current decreased to C / 20. The cells were then discharged at different C-rates with a discharge cutoff voltage of 2.8 V. The charge / discharge rates were determined based on the weight of the cathode active material, assuming a specific capacity of 230 mAh / g.

[0056] Comparative Example 1 A metal sulfate solution (MSO4) of NiSO4·6H2O, MnSO4·H2O, and CoSO4·7H2O in water was prepared with a Ni:Mn:Co stoichiometry of 8:1:1 and a total concentration of 2 moles per liter (M). Separate feeds of aqueous ammonium hydroxide (NH4OH) (5 M) and NaOH (2 M) solutions were used as the chelating and precipitating agents, respectively. A 3-liter (L) continuous stirred tank reactor (CSTR) was charged with a 0.75 M NH4OH solution, followed by the co-addition of the metal sulfate solution (MSO4), NH4OH, and NaOH. The flow rates of the MSO4 and NH4OH feeds were maintained at 0.108 liters per hour (L / h) and 0.083 L / h, respectively, such that the NH3:M molar ratio was kept constant at 1.92. To promote continuous precipitation, the NaOH addition rate was also kept constant at 0.108 L / h. The system reached steady state after 48–50 h, at which point all reagent concentrations remained constant. The reactor temperature was maintained at 50°C with an agitation rate of 1085 revolutions per minute (RPM). The solution pH was kept constant at 11.3 by adjusting the metal and NH4OH feeds. To prevent transition metal oxidation, the solution was continuously purged with N2 and blanketed with N2. The X-ray diffraction (XRD) pattern of the product is shown in Figure 7.

[0057] Example 1 A 0.6 m (molar, i.e., moles of solute (e.g., mixed metal sulfate) / kilogram of solvent) mixed metal sulfate solution (Ni / Co = 90 / 10) and a basic solution (i.e., 0.6 m aqueous NH4OH solution (aq) containing deionized (DI) water) were prepared. The mixed metal solution and the basic solution were preheated to 40 °C. Equal amounts of the mixed metal and basic solutions (i.e., 100 milliliters (mL) of each) were premixed in a 1 liter (L) reaction vessel and maintained at 40 °C. The mixed metal solution and the basic solution were co-added to the reactor at a rate of 1 mL / min, and mixing was continued for 5 hours. The pH of the solution was 7.01. The solid loading in the slurry was 1.1 wt%. The precipitate was then separated by filtration and washed with DI water until the conductivity of the filtrate was less than 350 microsiemens / centimeter (mS / cm). An SEM of the resulting mixed metal hydroxide is shown in Figure 1. The XRD pattern of the product is shown in FIG.

[0058] Example 2 A 0.6 m mixed metal sulfate solution (Ni / Co = 90 / 10) and a basic solution (i.e., 0.6 m NH4OH (aqueous) and 0.2 m NaOH solution) were prepared using DI water. The mixed metal solution and the basic solution were preheated to 40 °C. Equal amounts of the mixed metal solution and the basic solution (i.e., 100 mL each) were premixed in a 1 L reaction vessel and maintained at 40 °C. The mixed metal solution and the basic solution were co-added to the reactor at a rate of 1 mL / min, and mixing was continued for 5 hours. The pH of the solution was 7.41. The solid loading in the slurry was 1.6 wt%. The precipitate was then isolated by filtration and washed with DI water until the filtrate conductivity was less than 350 μS / cm. An SEM of the product is shown in Figure 2. An XRD of the product is shown in Figure 7.

[0059] Example 3 A 0.9 m mixed metal sulfate solution (Ni / Co = 90 / 10) and two separate basic solutions (i.e., 0.9 m NH4OH (aqueous) and 0.96 m NaOH solution) were prepared using DI water. The mixed metal solution and both basic solutions were preheated to 40 °C. Equal amounts of the mixed metal solution and basic solutions (i.e., 70 mL each) were mixed in a 1 L reaction vessel and maintained at 40 °C. All solutions, i.e., the mixed metal solution and the two basic solutions, were co-added to the reactor at a rate of 0.7 mL / min and mixed for 5 hours. The pH of the solution was 8.55. The solid loading in the slurry was 2.5 wt%. The precipitate was then isolated by filtration and washed with DI water until the filtrate conductivity was less than 350 μS / cm. An SEM of the product is shown in Figure 3. An XRD of the product is shown in Figure 7.

[0060] Example 4 A 0.9 m mixed metal sulfate solution (Ni / Co = 90 / 10) and two separate basic solutions (i.e., 0.9 m NH4OH (aqueous) and 1.29 m NaOH solution) were prepared using DI water. The mixed metal sulfate solution and both basic solutions were preheated to 40 °C. Equal amounts of the mixed metal sulfate solution and basic solution (i.e., 70 mL each) were premixed in a 1 L reaction vessel, and the temperature was maintained at 40 °C. The mixed metal sulfate solution and the two basic solutions were co-added to the reactor at a rate of 0.7 mL / min and then mixed for 5 hours. The pH of the solution was 9.54. The solid loading in the slurry was 2.6 wt % based on the total weight of the slurry. The precipitate was then isolated by filtration and washed with DI water until the filtrate conductivity was less than 350 μS / cm. An SEM of the product is shown in Figure 4. An XRD of the product is shown in Figure 7.

[0061] Example 5 DI water was used to prepare a 2.1 m mixed metal sulfate solution (Ni / Co / Mn = 1.89 m / 0.105 m / 0.105 m) and two separate basic solutions (i.e., 15 m NHOH(aq) and 8.33 m NaOH solutions). When preparing the mixed metal sulfate and NaOH solutions, a continuous N purge was utilized to displace any dissolved oxygen in the solution and avoid Mn oxidation in the subsequent co-precipitation. For the NHOH(aq) solution, an appropriate amount of water was purged with N, then the N purge was stopped, followed by the addition of the desired amount of concentrated NHOH(aq). The mixed metal solution and both basic solutions were preheated to 40 °C. The mixed metal and basic solutions were then premixed in a 1 L reaction vessel at a ratio of 14:2:5 (e.g., 140, 20, and 50 mL for mixed metal, NHOH(aq), and NaOH, respectively) and maintained at 40 °C. The mixed metal sulfate solution and the two basic solutions were added to the reactor at rates of 1.4, 0.2, and 0.5 mL, respectively, and mixed for 5 h. The solution was continuously purged with N2 and blanketed with N2 to prevent transition metal oxidation.

[0062] The pH of the solution was 8.92. The solids loading in the slurry was 8.9 wt %, based on the total weight of the slurry. The precipitate was then isolated by filtration and washed with DI water until the filtrate conductivity was less than 350 μS / cm.

[0063] The SEM of the product is shown in Figure 4. The XRD of the product is shown in Figure 8.

[0064] Example 6 The product of Example 5 was mixed with 15 μm lithium hydroxide monohydrate in a molar ratio of Li / Me=1.08 (Me is a combination of metallic Ni, Co, and Mn), followed by high-temperature calcination at 900° C. for 10 hours under an oxygen atmosphere. Figure 9 shows the XRD pattern, which indicates that the product is a highly ordered cation with a low Li / Ni cation disorder of 2.17 mole percent and a trace amount of lithium sulfate. TIFF2025531831000002.tif1016 shows a layered cathode active material (CAM). The particle size distribution analysis results are shown in Figure 11. The product had a D50 of 2.01 micrometers (μm) and a D90 of 5.03 μm.

[0065] Example 7 The product of Example 6 was further washed to remove residual Li compounds. 3 grams (g) of the CAM of Example 6 was rinsed with 60 g of cold DI water (T<10°C) for 10 minutes. The CAM was filtered and rinsed with an additional 60 g of cold DI water. The rinse water was analyzed for residual Li by titration. Residual LiOH and Li2CO3 were 0.09 wt% and 0.04 wt%, respectively, based on the total weight of the CAM before washing. The wet cake was further dried and analyzed by XRD to ensure structural integrity. As shown in Figure 10, the XRD pattern after the washing procedure was essentially the same as that of Example 6, but without the small peak associated with trace amounts of lithium sulfate.

[0066] Comparative Example 2 The product of Comparative Example 1 was calcined as described in Example 6. The particle size distribution is shown in Figure 12. D50 was 12.43 mm; D90 was 20.47 mm. The XRD of the product is shown in Figure 13.

[0067] Example 8: Electrochemical evaluation of the product of Example 7 The cathode active material of Example 7 was coated with conductive carbon (LITX 1000 manufactured by Cabot Corporation) using N-methyl-2-pyrrolidone (NMP) as a solvent. TM HP) and polyvinylidene fluoride (PVDF) binder (Kynar from Arkema) TM 500) in a weight ratio of 94:3:3 to prepare a slurry. TMA mixer was used. First, the PVDF binder and conductive carbon were mixed with NMP to obtain a uniform mixture. Then, the cathode active material and additional NMP were added and mixed until the desired viscosity (2000-5000 centipoise (cP)) was obtained. The final solids content was approximately 65 wt.% based on the total weight of the mixture, achieving a slurry with a honeycomb-like consistency. Al foil was used as the current collector, and a drawdown bar coater was used as the coating device for the slurry. The as-coated slurry was rapidly dried at 60°C for 5 minutes, then at 120°C for 5 minutes, and then vacuum dried at 110°C overnight. The mass loading of the cathode active material was approximately 20 mg / cm. 2 The final coating thickness was calendered to reach 30% of the targeted press porosity, resulting in a cathode with a coating thickness of 110 micrometers.

[0068] 2032-type coin cells were used for electrochemical evaluation, using Li metal as the cathode and anode, and an electrolyte of 1.2 M LiPF6 in EC:EMC (3:7) with 2 wt% VC based on the total weight of LiPF6, EC, and EMC. Upon assembly, each cell was given a 6-hour rest period before the formation cycle. The formation cycle involved a C / 10 charge to 4.3 V at a constant voltage (CV), held at 4.3 V until the current density decreased to C / 20, followed by a C / 10 discharge to 2.8 V with a 10-minute rest period. After the three formation cycles, the cells were subjected to 100 C / 3 charge-discharge cycles. The charge-discharge rate was determined based on the weight of the cathode active material, assuming a capacity of 230 mAh / g.

[0069] The present disclosure further encompasses the following aspects.

[0070] Embodiment 1. A method of making a single crystal cathode active material, the method comprising: providing a metal salt solution comprising nickel, cobalt, manganese, aluminum, or a combination thereof; combining the metal salt solution with a basic solution, wherein the combination of the metal salt solution and the basic solution is maintained at a pH of 10 or less to form a metal hydroxide precursor; adding a lithium compound to the metal hydroxide precursor to form a metal hydroxide precursor mixture; and heat-treating the mixture to form a single crystal cathode active material.

[0071] Embodiment 2. The method of embodiment 1, wherein the pH is at least 7, preferably at least 8.

[0072] Embodiment 3. The method of embodiment 1 or 2, wherein the metal salt solution is a metal sulfate solution in water, preferably an aqueous solution comprising NiSO4·-6H2O, MnSO4·H2O, and CoSO4·7H2O.

[0073] Embodiment 4. The method of any preceding embodiment, wherein the basic solution comprises an alkali metal hydroxide, ammonium hydroxide, or a combination thereof, preferably sodium hydroxide and ammonia, and more preferably, the sodium hydroxide and ammonia are present in a ratio of 2:1 to 1:2, preferably 1.5:1 to 1:1.5, more preferably 1.2:1 to 1:1.

[0074] Embodiment 5. The method of any preceding embodiment, wherein the metal hydroxide precursor mixture is semi-crystalline and comprises a beta phase (B) and an intermediate phase (I).

[0075] Embodiment 6. The beta phase has the formula M(OH), wherein M comprises Ni, Mn, Co, Al, or a combination thereof, and the beta phase is CuK α 6. The method of embodiment 5, wherein the compound is characterized by a peak at 17 to 23 degrees 2θ when analyzed by X-ray diffraction using X-rays.

[0076] Aspect 7. The intermediate phase has the formula M(OH)2·yZ, where M includes Ni, Mn, Co, Al, or a combination thereof, 0 < y < 0.75, and Z represents H2O, a solvent, an anion, or a combination thereof, the solvent is preferably ROH or RCOOH, R is an alkyl group having 1 to 3 carbon atoms, or Z is preferably OH - , SO4 2- , NO3 - , CO3 2- , F - , Cl - , or a combination thereof, more preferably H2O or SO4 2- , more preferably H2O, the method according to embodiment 5 or 6.

[0077] Aspect 8. Nickel, cobalt, manganese, aluminum, or a combination thereof is included in nickel, cobalt, and manganese at a molar ratio of Ni:Co:Mn of greater than 0 to greater than 1:greater than 0 to greater than 1:greater than 0 to greater than 1, preferably 1:0.125:0.125, most preferably 1:0.18:0.18, the method according to any of the preceding aspects.

[0078] Aspect 9. The metal hydroxide precursor includes a residual S content of at least 0.1 wt% to less than 3 wt%, preferably less than 2.5 wt%, more preferably less than 2 wt%, based on the total weight of the metal hydroxide precursor, the method according to any of the preceding aspects.

[0079] Aspect 10. The lithium compound includes lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, or a combination thereof, the method according to any of the preceding aspects.

[0080] Aspect 11. The heat treatment includes heat treatment at a temperature of 600 to 1100 °C for 2 to 24 hours, preferably 800 to 1000 °C, more preferably 850 to 950 °C, the method according to any of the preceding aspects.

[0081] Aspect 12. The heat treatment step is only one, the method according to any of the preceding aspects.

[0082] Aspect 13. The method according to any one of the preceding aspects, wherein the molar ratio of the lithium compound to the metal hydroxide precursor is 1 to 1.2, preferably 1.02 to 1.15, more preferably 1.05 to 1.10.

[0083] Aspect 14. The method according to any one of the preceding aspects, wherein the cathode active material has the formula Li x MO2, wherein M is Ni, Co, Mn, Al, or a combination thereof, and 0 < x ≤ 1.2.

[0084] Aspect 15. The cathode active material has the formula Li x Ni y Co z Mn v O2, wherein 0 < x ≤ 1.2 and 0.8 ≤ (y + z + v) ≤ 1.1, preferably, wherein y is 0.1 to 1, z is 0.01 to 0.1, v is 0.01 to 0.1, and more preferably the formula LiNi 0.88 Co 0.06 Mn 0.06 O2, the method according to aspect 14.

[0085] Aspect 16. The method according to any one of the preceding aspects, wherein the cathode active material formed during the heat treatment comprises a monodisperse single crystal having a unimodal particle size distribution.

[0086] Aspect 17. The method according to any one of the preceding aspects, wherein the cathode active material comprises a single crystal having a D50 particle size determined according to ASTM C115 that is greater than 100 nm and less than 10 μm, preferably 1 to 5 μm, more preferably 1 to 3 μm.

[0087] Aspect 18. The method according to any one of the preceding aspects, wherein the cathode active material comprises a single crystal having a D90 particle size determined according to ASTM C115 that is greater than 1 μm and less than 20 μm, preferably 3 to 10 μm, more preferably 5 to 8 μm.

[0088] Embodiment 19. The method of any preceding embodiment, further comprising washing the cathode active material after the heat treatment.

[0089] Embodiment 20. The method of any preceding embodiment, wherein the cathode active material comprises less than 10, preferably less than 7 wt.%, based on the total weight of the cathode active material, of residual lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, lithium sulfate, or a combination thereof on a surface of the cathode active material.

[0090] Embodiment 21. The method of any preceding embodiment, wherein the cathode active material is characterized by an average discharge capacity of greater than 200 mAh / g at a C / 3 discharge rate for half cells over 100 cycles.

[0091] Embodiment 22. The method of any preceding embodiment, wherein the metal salt solution comprises metals obtained from recycled feedstock, preferably post-industrial recycled feedstock, post-consumer recycled feedstock, or a combination thereof.

[0092] Embodiment 23. The method of any preceding embodiment, wherein the mixture subjected to the heat-treating step comprises 0.1 to 5 wt. % lithium carbonate.

[0093] Embodiment 24. A method of making a monodisperse single crystalline cathode active material, comprising providing a metal hydroxide precursor comprising nickel, cobalt, manganese, aluminum, or a combination thereof, wherein the metal hydroxide precursor is characterized as being semi-crystalline and in the beta phase, such as CuK. α a beta phase characterized by peaks at 17 to 23 degrees 2θ when analyzed by X-ray diffraction using X-rays;

[0094] a mesophase characterized in that HO, ROH, RCOOH, anions, or combinations thereof are incorporated into the structure of the mesophase, and R is an alkyl group of 1 to 3 carbon atoms; adding a lithium compound to a metal hydroxide precursor to form a mixture; and heating the mixture in a single-step calcination to form a monodisperse single crystalline cathode active material having a unimodal particle size distribution and a D50 particle size distribution of 100 nm to 5 μm or a D90 particle size distribution of 1 to 10 μm.

[0095] 25. The anion is OH - , SO4 2- , NO3 - , CO3 2- , F - , Cl - or a combination thereof.

[0096] Embodiment 26 The method of embodiment 24, wherein water, sulfate ions, or both are incorporated into the structure of the mesophase.

[0097] Embodiment 27. The method of any one of embodiments 24-26, wherein the beta phase has the formula M(OH)2, where M is Ni, Co, Mn, Al, or a combination thereof.

[0098] Embodiment 28. The method of any one of embodiments 24 to 27, wherein the nickel, cobalt, manganese, aluminum, or combination thereof comprises nickel, cobalt, and manganese, and the molar ratio of Ni:Co:Mn is greater than 0 to 1: greater than 0 to 1: greater than 0 to 1, preferably 1:0.125:0.125, and most preferably 1:0.18:0.18. (90 / 5 / 5).

[0099] Embodiment 29. The method of any one of embodiments 24 to 28, wherein the lithium compound comprises lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, or a combination thereof.

[0100] Aspect 30. The method according to any one of Aspects 24 to 29, wherein the heat treatment includes heating at a temperature of 600 to 1100 °C for 2 to 24 hours, preferably 800 to 1000 °C, or more preferably 850 to 950 °C.

[0101] Aspect 31. The method according to any one of Aspects 24 to 30, wherein the molar ratio of the lithium compound to the metal hydroxide precursor is 1 to 1.2, preferably 1.02 to 1.15, more preferably 1.05 to 1.10.

[0102] Aspect 32. The method according to any one of Aspects 24 to 31, wherein the cathode active material has the formula Li x MO2, where M is Ni, Co, Mn, Al, or a combination thereof, and 0 < x ≤ 1.2.

[0103] Aspect 33. The method according to Aspect 32, wherein the cathode active material has the formula Li x Ni y Co z Mn v O2, where 0 < x ≤ 1.2 and 0.8 ≤ (y + z + v) ≤ 1.1, preferably, where y is 0.1 to 1, z is 0.01 to 0.1, v is 0.01 to 0.1, and more preferably the formula LiNi 0.88 Co 0.06 Mn 0.06 O2.

[0104] Aspect 34. The method according to any one of Aspects 24 to 33, further comprising washing the cathode active material after the heat treatment.

[0105] Aspect 35. The method according to any one of Aspects 24 to 34, wherein the cathode active material contains less than 10% by weight, based on the total weight of the cathode active material, of lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, lithium sulfate, or a combination thereof on the surface of the cathode active material.

[0106] Aspect 36. The method according to any one of Aspects 24 to 35, wherein the cathode active material is characterized by an average discharge capacity exceeding 200 mAh / g at a discharge rate of C / 3 for a half cell over 100 cycles.

[0107] Aspect 37. The method according to any one of Aspects 24 to 36, wherein the mixture subjected to heat treatment contains 0.1 to 5% by weight of lithium carbonate.

[0108] Aspect 38. A metal hydroxide composition comprising: a metal hydroxide containing nickel, cobalt, manganese, aluminum, or a combination thereof, the metal hydroxide being semi-crystalline, characterized by being in the beta phase and having a peak at 17 to 23 degrees 2θ when analyzed by X-ray diffraction using Cu K α radiation, having the formula M(OH)2, wherein M is Ni, Co, Mn, Al, or a combination thereof, the beta phase, and

[0109] an intermediate phase, characterized in that H2O, ROH, RCOOH, anions, or a combination thereof are incorporated into the structure of the intermediate phase, and R is an alkyl group having 1 to 3 carbon atoms, the intermediate phase.

[0110] Aspect 39. The metal hydroxide composition according to Aspect 38, wherein water, sulfate ions, or both are incorporated into the structure of the intermediate phase.

[0111] Aspect 40. A single crystal cathode active material having the formula Li x MO2, wherein M is Ni, Co, Mn, Al, or a combination thereof, 0 < x ≦ 1.2, having a D50 particle size distribution of 100 nm to 5 μm or a unimodal particle size distribution of a monodisperse single crystal having a D90 particle size of 1 to 10 μm, and the presence of Li2SO4.

[0112] Aspect 41. The presence of Li2SO4 is Cu K α41. The single crystal active material of embodiment 40, as determined by a peak at 22 to 29 degrees 2θ when analyzed by X-ray diffraction using X-rays.

[0113] Example 42: The single crystalline active material of example 40 or 42, made by the method of any one of examples 1-37.

[0114] Embodiment 43: The metal hydroxide composition of embodiment 38 or 39 made by a process comprising: providing a metal salt solution comprising nickel, cobalt, manganese, aluminum, or a combination thereof; and combining the metal salt solution with a basic solution, wherein the combined metal salt solution and the basic solution are maintained at a pH of less than or equal to 10, preferably at least 7, and more preferably at least 8, to form a metal hydroxide precursor.

[0115] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., the range "up to 25% by weight, or more specifically, 5% to 20% by weight" includes the endpoints of the range "5% to 25% by weight" and all intermediate values, etc.). Additionally, stated upper and lower limits can be combined to form ranges (e.g., "at least 1 or at least 2% by weight" and "up to 10 or 5% by weight" can be combined as the ranges "1 to 10% by weight" or "1 to 5% by weight" or "2 to 10% by weight" or "2 to 5% by weight"). "Or" means "and / or" unless otherwise specified.

[0116] The present disclosure may alternatively comprise, consist of, or consist essentially of any suitable components disclosed herein. The present disclosure may additionally or alternatively be formulated to be devoid of or substantially free of any components, materials, ingredients, adjuvants, or species used in prior art compositions or that are not necessary to achieve the function and / or purpose of the present disclosure.

[0117] All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in this application contradicts or conflicts with a term in an incorporated reference, the term from this application will take precedence over the conflicting term from the incorporated reference.

[0118] Unless otherwise specified herein, all test standards are the latest standards in effect as of the filing date of this application or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

Claims

1. A method for producing a single-crystal cathode active material: To provide a metal salt solution containing nickel, cobalt, manganese, aluminum, or a combination thereof; The metal salt solution and the basic solution are combined, wherein the combination of the metal salt solution and the basic solution is maintained at a pH of 10 or less, and a metal hydroxide precursor is formed; Adding a lithium compound to the aforementioned metal hydroxide precursor to form a metal hydroxide precursor mixture; and The metal hydroxide precursor mixture is heat-treated to form the single-crystal cathode active material. Methods that include...

2. The metal salt solution is a metal sulfate solution in water, preferably NiSO4. ４ 6H ２ O, MnSO ４ ・H ２ O, and CoSO ４ 7H ２ It is an aqueous solution containing O; and The method according to claim 1, wherein the basic solution comprises an alkali metal hydroxide, ammonium hydroxide, or a combination thereof, preferably sodium hydroxide and ammonia, and more preferably the sodium hydroxide and ammonia are present in a ratio of 2:1 to 1:2, preferably 1.5:1 to 1:1.5, and more preferably 1.2:1 to 1:

1.

3. The method according to claim 1, wherein the metal hydroxide precursor mixture is semicrystalline and comprises a beta phase (B) and an intermediate phase (I).

4. The aforementioned beta phase is given by formula M(OH) ２ The formula comprises, where M includes Ni, Mn, Co, Al, or a combination thereof, and the beta phase is Cu K α When analyzed by X-ray diffraction using lines, it is characterized by a peak at 17–23 degrees 2θ; and The intermediate phase has the formula M(OH) ２ ·yZ, where M includes Ni, Mn, Co, Al, or a combination thereof, 0 < y < 0.75, and Z represents H ２ O, a solvent, an anion, or a combination thereof, the solvent being preferably ROH or RCOOH, R being an alkyl group of 1 to 3 carbon atoms, or Z being preferably OH － 、SO ４ ２－ 、NO ３ － 、CO ３ ２－ 、F － 、Cl － 、or a combination thereof, more preferably H ２ O or SO ４ ２－ 、more preferably H ２ O, The method according to claim 3.

5. The method according to claim 1, wherein the nickel, cobalt, manganese, aluminum, or combination thereof comprises nickel, cobalt, and manganese in a Ni:Co:Mn molar ratio of greater than 0 to 1:0 to greater than 1:0 to greater than 1, preferably 1:0.125:0.125, and most preferably 1:0.18:0.

18.

6. The method according to claim 1, wherein the metal hydroxide precursor contains a residual sulfur content of at least 0.1% to less than 3% by weight, preferably 0.1% to less than 2.5% by weight, and more preferably 0.1% to less than 2% by weight, based on the total weight of the metal hydroxide precursor.

7. The lithium compound may include lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, or a combination thereof; The heat treatment includes heat treatment at a temperature of 600 to 1100°C for 2 to 24 hours, preferably at 800 to 1000°C, more preferably at 850 to 950°C; Is there only one heat treatment process? The pH is at least 7, preferably at least 8; The cathode active material contains less than 10% by weight, preferably less than 7% by weight, of residual lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, lithium sulfate, or a combination thereof on the surface of the cathode active material, based on the total weight of the cathode active material; The metal salt solution contains a metal obtained from recycled feedstock, preferably post-industrial recycled feedstock, post-consumer recycled feedstock, or a combination thereof; The mixture subjected to the heat treatment step contains 0.1 to 5% by weight of lithium carbonate; The molar ratio of the lithium compound to the metal hydroxide precursor is 1 to 1.2, preferably 1.02 to 1.15, more preferably 1.05 to 1.10; or, The combination of those, The method according to claim 1.

8. The cathode active material is of formula Li ｘ MO ２ The method according to claim 1, wherein the formula is Ni, Co, Mn, Al, or a combination thereof, and 0 < x ≤ 1.

2.

9. The cathode active material is of formula Li ｘ Ni ｙ Co ｚ Mn ｖ O ２ The formula has the following characteristics: 0 < x ≤ 1.2 and 0.8 ≤ (y + z + v) ≤ 1.1, preferably where y is 0.1 to 1, z is 0.01 to 0.1, and v is 0.01 to 0.1, more preferably the formula LiNi ０．８８ Co ０．０６ Mn ０．０６ O ２ The method according to claim 8, wherein the method is characterized by having the following:

10. The method according to claim 1, wherein the cathode active material formed during the heat treatment includes a monodisperse single crystal having a monomodal grain size distribution.

11. The cathode active material is D50 particle size determined according to ASTM C115, which is greater than 100 nm and less than 10 μm, preferably 1 to 5 μm, more preferably 1 to 3 μm; and The D90 particle size, determined according to ASTM C115, is greater than 1 μm and less than 20 μm, preferably 3 to 10 μm, and more preferably 5 to 8 μm. The method according to claim 1, comprising a single crystal having the following properties.

12. The method according to claim 1, wherein the cathode active material is characterized by having an average discharge capacity of more than 200 mAh / g at a discharge rate of C / 3 for half a cell over 100 cycles.

13. A method for producing a monodisperse single crystal cathode active material, To provide a metal hydroxide precursor containing nickel, cobalt, manganese, aluminum, or a combination thereof, The aforementioned metal hydroxide precursor is characterized by being semi-crystalline. It is the beta phase, Cu K α When analyzed using X-ray diffraction, the beta phase is characterized by a peak at 17–23 degrees 2θ, Intermediate phase, H ２ O, ROH, RCOOH, OH － SO ４ ２－ NO ３ － CO ３ ２－ F － , Cl － To provide a metal hydroxide precursor comprising an intermediate phase characterized in that an anion containing, or a combination thereof, or a combination thereof is incorporated into the structure of the intermediate phase, preferably water, sulfate ions, or both, are incorporated into the structure of the intermediate phase, and R is an alkyl group with 1 to 3 carbon atoms; Adding a lithium compound to the metal hydroxide precursor to form a mixture; and The mixture is heated in a single-step calcination to form a monodisperse single-crystal cathode active material having a unimodal particle size distribution and a D50 particle size distribution of 100 nm to 5 μm, a D90 particle size distribution of 1 to 10 μm, or both. Methods that include...

14. The aforementioned beta phase is given by formula M(OH) ２ The method according to claim 13, wherein M is Ni, Co, Mn, Al, or a combination thereof.

15. The method according to claim 13, wherein the nickel, cobalt, manganese, aluminum, or combination thereof comprises nickel, cobalt, and manganese, and the molar ratio of Ni:Co:Mn is greater than 0 to greater than 1:0 to greater than 1:0 to greater than 1, preferably 1:0.125:0.125, most preferably 1:0.18:0.

18.

16. The lithium compound may include lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, or a combination thereof; The heat treatment includes heating at a temperature of 600 to 1100°C for 2 to 24 hours, preferably at 800 to 1000°C, or more preferably at 850 to 950°C; The molar ratio of the lithium compound to the metal hydroxide precursor is 1 to 1.2, preferably 1.02 to 1.15, and more preferably 1.05 to 1.10; The cathode active material contains less than 10% by weight of residual lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, lithium sulfate, or a combination thereof on the surface of the cathode active material, based on the total weight of the cathode active material; The mixture subjected to the heat treatment contains 0.1 to 5% by weight of lithium carbonate; or, The combination of those, The method according to claim 13.

17. The cathode active material is of formula Li ｘ MO ２ The formula has, where M is Ni, Co, Mn, Al, or a combination thereof, 0 < x ≤ 1.2, and preferably the cathode active material is of the formula Li ｘ Ni ｙ Co ｚ Mn ｖ O ２ The formula has the following characteristics, where 0 < x ≤ 1.2 and 0.8 ≤ (y + z + v) ≤ 1.1, preferably y is 0.1 to 1, z is 0.01 to 0.1, v is 0.01 to 0.1, and more preferably the formula LiNi ０．８８ Co ０．０６ Mn ０．０６ O ２ The method according to claim 13, having the following characteristics.

18. The method according to claim 13, wherein the cathode active material is characterized by having an average discharge capacity of more than 200 mAh / g at a discharge rate of C / 3 for half a cell over 100 cycles.

19. A metal hydroxide composition, which includes: The material contains a metal hydroxide comprising nickel, cobalt, manganese, aluminum, or a combination thereof, wherein the metal hydroxide is semi-crystalline. It is the beta phase, Cu K α When analyzed by X-ray diffraction using a linear X-ray beam, it is characterized by a peak at 17–23 degrees 2θ, and the formula M(OH) ２ The formula has a beta phase in which M is Ni, Co, Mn, Al, or a combination thereof. Intermediate phase, H ２ The intermediate phase is characterized in that O, ROH, RCOOH, anions, or combinations thereof are incorporated into the structure of the intermediate phase, where R is an alkyl group with 1 to 3 carbon atoms, and preferably water, sulfate ions, or both are incorporated into the structure of the intermediate phase. A metal hydroxide composition containing the following:

20. Formula Li ｘ MO ２ A single crystal cathode active material having the formula, where M is Ni, Co, Mn, Al, or a combination thereof, and 0 < x ≤ 1.

2. A monomodal grain size distribution of a monodisperse single crystal having a D50 grain size distribution of 100 nm to 5 μm, a D90 grain size of 1 to 10 μm, or both, and Li ２ SO ４ The existence of A single-crystal cathode active material characterized by the following:

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